HEAT GUN

Description

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Japanese patent application serial number 2024-205194 filed on Nov. 26, 2024, the contents of which are fully incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a heat gun.

BACKGROUND

A heat gun that is configured to blow air heated by a heating element from an outlet is known. For example, China Utility Model Publication No. 207907487 discloses a heat gun having a heater housing that houses a heating element, and a cover part that houses the heater housing.

SUMMARY

The cover part may be heated by heat transfer from the heating element in use of the heat gun. If excessively heated, an outermost layer of the cover part may be changed in material or shape, so that a user may not be able to easily hold the cover part. It is accordingly desirable to provide a heat gun in which heat is not easily transferred from the heating element to the outermost layer of the cover part.

The present discloser can be embodied as the following aspects.

According to one non-limiting aspect of the present disclosure, a heat gun is provided that is configured to heat and blow air. The heat gun includes a fan, a heating element, a heater housing, an inner cover part and an outer cover part. The fan is rotated by driving of a motor and generates air flow. The heating element generates heat by energization. The heater housing houses the heating element. The heater housing includes: (i) a cylindrical body extending in a longitudinal direction that defines a front-rear direction of the heat gun; (ii) a flow passage that is defined inside the body and through which the air flow passes, and (iii) an outlet that is formed in a front end part of the body and from which the air flow passing through the flow passage is blown to the outside. The inner cover part is arranged outside of the heater housing in a radial direction orthogonal to the longitudinal direction of the heater housing, and covers at least part of the heater housing. The outer cover part is arranged outside of the inner cover part in the radial direction so as to be apart from the inner cover part, and covers at least part of the inner cover part. At least one through-opening is defined between the outer cover part and the inner cover part.

In the heat gun according to this aspect, an air layer is formed between the outer cover part and the inner cover part, so that heat transfer from the inner cover part to the outer cover part is restrained or prevented. Thus, heat is not easily transferred from the heating element to the outer cover part, and the outer cover part is restrained or prevented from being changed in material or shape.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the outer appearance of a heat gun according to a first embodiment.

FIG. 2 is a sectional view taken along line II-II in FIG. 1.

FIG. 3 is an explanatory view showing a blower part, a heating element and a detachment mechanism in an enlarged view.

FIG. 4 is a perspective view showing the outer appearance of the heating element.

FIG. 5 is a perspective view showing the outer appearance of the detachment mechanism.

FIG. 6 is a sectional view with the detachment mechanism operated.

FIG. 7 is a front view of the detachment mechanism.

FIG. 8 is a front view for showing a positional relation between a through-opening of the detachment mechanism and a body housing.

FIG. 9 is a sectional view taken along line IX-IX in FIG. 7.

FIG. 10 is a sectional view taken along line X-X in FIG. 3.

FIG. 11 is a first explanatory view showing a modification of a connection part.

FIG. 12 is a second explanatory view showing a modification of the connection part.

FIG. 13 is a third explanatory view showing a modification of the connection part.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Representative, non-limiting examples of the present invention are described in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed below may be utilized separately or in conjunction with other features and teachings to provide improved tools and manufacturing and using methods of the tools.

Moreover, combinations of features and steps disclosed within the following detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the representative examples described above and below, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.

All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.

In at least one non-limiting embodiment according to the present disclosure, the heat gun may further have a grip part that extends in a direction crossing the longitudinal direction. The outer cover part may overlap with a half or more of a region of the heating element when the heat gun is viewed from above, where the extending direction of the grip part defines an up-down direction of the heat gun.

According to this embodiment, the outer cover part can be suitably held by a user, so that the workability of the heat gun is improved.

In addition or in the alternative to the preceding embodiment, the heat gun may further have at least one connection part that connects an outer surface of the inner cover part and an inner surface of the outer cover part and defines the at least one through-opening together with the outer cover part and the inner cover part.

According to this embodiment, the outer cover part is arranged radially outside of the inner cover part so as to be apart from the inner cover part, with a simple structure having the connection part.

In addition or in the alternative to the preceding embodiments, the heat gun may further have a body housing that houses the fan. The outer cover part may be arranged apart from the inner cover part and the body housing.

According to this embodiment, heat transfer from the outer cover part to the body housing is restrained or prevented.

In addition or in the alternative to the preceding embodiments, the heat gun may further have a grip part that extends in a direction crossing the longitudinal direction. The extending direction of the grip part may define an up-down direction of the heat gun. The at least one through-opening may be defined to include at least either one of a first through-opening that is arranged directly above a center of the heater housing, and a second through-opening that is arranged directly below the center of the heater housing, when the heat gun is viewed from the front.

According to this embodiment, the connection part is not arranged at least either directly above or directly below the center of the heater housing. Thus, when the heat gun is used in an attitude in which the grip part extends in the vertical direction, heat from the heating element is restrained or prevented from being transferred in the vertical direction via the connection part.

In addition or in the alternative to the preceding embodiments, the heat gun may further have a grip part that extends in a direction crossing the longitudinal direction. The extending direction of the grip part may define an up-down direction of the heat gun, and a direction orthogonal to the front-rear direction and the up-down direction may define a left-right direction. The at least one through-opening may be defined to include at least either one of a third through-opening that is arranged to the right of a center of the heater housing, and a fourth through-opening that is arranged to the left of the center of the heater housing, when the heat gun is viewed from the front.

According to this embodiment, the connection part is not arranged at least either to the left or right of the center of the heater housing. Thus, when the heat gun is used in an attitude in which the grip part extends in a direction orthogonal to the vertical direction, heat from the heating element is restrained or prevented from being transferred in the vertical direction via the connection part.

In addition or in the alternative to the preceding embodiments, the heat gun may further have a body housing that houses the fan. The at least one through-opening may be arranged to include a region that does not overlap with the body housing, when the heat gun is viewed from the front.

According to this embodiment, air easily passes through the through-opening, so that the effect of air-cooling the outer cover part and the inner cover part by provision of the through-opening is improved.

In addition or in the alternative to the preceding embodiments, a length of the outer cover part in the front-rear direction may be smaller than a length of the inner cover part in the front-rear direction.

According to this embodiment, a part of the inner cover part is exposed to the outside without being covered by the outer cover part, so that the effect of air-cooling the inner cover part is improved.

In addition or in the alternative to the preceding embodiments, a front end of the outer cover part may be arranged rearward of a front end of the inner cover part.

According to this embodiment, the vicinity of the outlet of the heat gun is reduced in diameter, compared with a configuration in which the front end of the inner cover part is flush with the front end of the outer cover part. Thus, the vicinity of the outlet of the heat gun does not easily come into contact with an object to be heat treated, so that the workability is improved in the vicinity of the object to be heat treated with the heat gun.

In addition or in the alternative to the preceding embodiments, the outer cover part may have a projection protruding outward from an outer surface of the outer cover part in the radial direction.

According to this embodiment, the projection serves as a slip stopper, so that the outer cover part of the heat gun is easy to hold.

In addition or in the alternative to the preceding embodiments, the heat gun may further have a push-out part that is arranged between the heater housing and the inner cover part and connected to the inner cover part. The outer cover part and the inner cover part may be integrally movable forward. When the outer cover part is moved forward, the push-out part may be moved forward together with the inner cover part to forwardly push out a nozzle attachment fitted on a front end part of the heater housing.

According to this embodiment, the nozzle attachment fitted on the heater housing can be detached in a simple manner by utilizing the outer cover part and the inner cover part.

In addition or in the alternative to the preceding embodiments, the heat gun may have a maximum length of 160 mm to 200 mm in the front-rear direction.

According to this embodiment, the heat gun is provided that is easy to carry.

In addition or in the alternative to the preceding embodiments, the distance between an outer surface of the inner cover part and an inner surface of the outer cover may be 5 mm or more.

According to this embodiment, the thickness of the air layer between the inner cover part and the outer cover part is secured, so that heat transfer from the inner cover part to the outer cover part is effectively restrained or prevented.

In addition or in the alternative to the preceding embodiments, a ratio of a width of a contour of an outer surface of the outer cover part in the radial direction to a width of a contour of an outer surface of the inner cover part in the radial direction may be 125% or more.

According to this embodiment, heat transfer from the inner cover part to the outer surface of the outer cover part is effectively restrained or prevented by arranging the outer surface of the outer cover part apart from the outer surface of the inner cover part.

In addition or in the alternative to the preceding embodiments, the heat gun may further have a battery mounting part configured to electrically connect a battery that supplies power to the heating element. The maximum temperature of a front end part of the heater housing may be 600° C. or higher when the heat gun is driven by the battery.

According to this embodiment, the heat gun is provided with high portability and configured to blow air flow of higher temperature than a conventional one.

A. First Embodiment

A1. The structure of a heat gun 100:

The structure of a heat gun 100 according to the first embodiment of the present disclosure is now described with reference to FIGS. 1 to 4. As shown in FIG. 1, the heat gun 100 is a heat treatment power tool that blows heated air from an outlet 66. The heat gun 100 is used for various applications such as bending a resin product, peeling off a coating or an adhesive seal, deforming a resin tube by heating, drying a material, and rust proofing.

As shown in FIG. 1, an outer shell of the heat gun 100 is defined by a body housing 10 and a detachment mechanism 50. The detachment mechanism 50 is mounted to an end part of the body housing 10. A heater housing 60 is housed in the detachment mechanism 50. The heater housing 60 has a generally cylindrical, elongate shape. A longitudinal direction of the heater housing 60 defines a blowing direction of air from the heat gun 100.

The body housing 10 includes a handle housing 12 and a blower housing 14. The blower housing 14 has a generally circular cylindrical, elongate shape extending parallel to the longitudinal direction of the heater housing 60. The handle housing 12 extends in a direction crossing a longitudinal direction of the blower housing 14 (in this embodiment, in a direction substantially orthogonal to the longitudinal direction) substantially from a center of the blower housing 14 in the longitudinal direction. The detachment mechanism 50 is mounted to an end part of the blower housing 14.

In this specification, as for the directions of the heat gun 100, the longitudinal direction of the heater housing 60 is defined as a front-rear direction of the heat gun 100. In the front-rear direction, the side of the outlet 66 is defined as a front side, and the side of an inlet 142 is defined as a rear side. As shown in FIG. 2, the heat gun 100 according to this embodiment has a maximum length L1 of approximately 190 mm in the front-rear direction, and is of an easy-to-carry handy type. It is desirable that the maximum length L1 is 160 mm to 200 mm in order to enhance the portability. Thus, the heat gun 100 according to this embodiment is also referred to as a portable heat treatment tool.

In this specification, a direction orthogonal to the longitudinal direction and corresponding to the extending direction of the handle housing 12 is defined as an up-down direction. In the up-down direction, the side of the blower housing 14 is defined as an upper side, and the side of a protruding end (free end) of the handle housing 12 is defined as a lower side. A direction orthogonal to the front-rear direction and the up-down direction is defined as a left-right direction. A direction orthogonal to the longitudinal direction is defined as a radial direction. The radial direction means a radial direction centering on the longitudinal direction.

As shown in FIGS. 1 and 2, the blower housing 14 is connected to the upper side of the handle housing 12. The blower housing 14 has a generally circular cylindrical shape extending in the front-rear direction. The blower housing 14 has the inlet 142 though which outside air is sucked in, an opening 144 and an operating part 18.

The inlet 142 is formed in a rear part of the blower housing 14. The inlet 142 is an opening that communicates the inside of the blower housing 14 with the outside. The opening 144 is formed in a front end of the blower housing 14.

The blower housing 14 houses a blower part 30 for generating air flow. The heater housing 60 is arranged in front of the blower part 30. A rear part of the heater housing 60 is housed in the blower housing 14, and a front part of the heater housing 60 protrudes forward from the opening 144 and is exposed from the blower housing 14. The heater housing 60 houses a heating element 70. The heating element 70 heats the air flow supplied from the blower part 30.

The detachment mechanism 50 is mounted to the front end opening 144 of the blower housing 14. The detachment mechanism 50 is arranged outside of the heating element 70 and the heater housing 60 in the radial direction, and also serves as a cover for covering the circumferences of the heating element 70 and the heater housing 60.

As shown in FIGS. 1 and 2, the handle housing 12 includes a grip part 20, a switch 24, a trigger 26 and a controller 80. The trigger 26 is provided on the front side of the grip part 20. The trigger 26 is configured to be depressed and released by a user.

The switch 24 is housed inside the handle housing 12 behind the trigger 26. The switch 24 is connected to the controller 80. The switch 24 is switched on and off according to the depressing operation of the trigger 26. In this embodiment, the heat gun 100 has a lock-on button 28 having a function of maintaining the heat gun 100 in an ON state.

As shown in FIG. 2, the grip part 20 has a generally circular cylindrical shape extending in a direction orthogonal to the longitudinal direction. The grip part 20 is a part of the handle housing 12 and is configured to be held by a user. The handle housing 12 is integrally formed with the blower housing 14. Thus, the handle housing 12 and the blower housing 14 form the integral body housing 10. The body housing 10 is, for example, formed of a resin material and formed by fixedly joining a pair of right and left housing halves.

As shown in FIG. 2, a battery mounting part 40 is provided on the protruding end of the handle housing 12. The battery mounting part 40 is configured such that a rechargeable battery BT is removably mounted thereto. In FIG. 2, for ease of technical understanding, only an outer contour of the battery BT is shown by a broken line. The battery BT is a power source that can be repeatedly charged, and is a known battery pack or secondary battery, such as a lithium-ion battery including cells. The battery BT has, for example, a rated voltage of 36V and a battery capacity of 4.0 to 5.0 Ah.

The battery mounting part 40 includes terminals 42 and recessed guide grooves 44. The guide grooves 44 are configured to be engaged with rails 172 formed on the battery BT and define a mounting/removing direction of the battery BT. The terminals 42 are connected to a power terminal formed on the battery BT. The terminals 42 are electrically connected to the controller 8, a motor 32 and the heating element 70, via wirings arranged in the body housing 10. The heat gun 100 may have a power cord for supplying power from an external AC power source, in place of the battery mounting part 40.

As shown in FIG. 1, in this embodiment, a lower end of the handle housing 12, on which the battery mounting part 40 is formed, is configured to have a length and a width in the front-rear and left-right directions larger than the outer diameter of the grip part 20. A right surface of a right part 40R of the lower end of the handle housing 12 is configured to be substantially flush with a right surface of a right part 14R of the blower housing 14. When the heat gun 100 is placed on a horizontal plane in an attitude with the right parts 14R and 40R facing vertically downward (hereinafter also referred to as a “first attitude”), the longitudinal direction of the heater housing 60 is substantially parallel to the horizontal plane.

A left surface of a left part 40L of the lower end of the handle housing 12 is configured to be substantially flush with a left surface of a left part 14L of the blower housing 14. When the heat gun 100 is placed on a horizontal plane in an attitude with the left parts 14L and 40L facing vertically downward (hereinafter also referred to as a “second attitude”), the longitudinal direction of the heater housing 60 is substantially parallel to the horizontal plane.

Further, in the heat gun 100 of this embodiment, a rear part 40B of the lower end of the handle housing 12 is configured to be substantially flush with a rear part 14B of the blower housing 14. When the heat gun 100 is placed on a horizontal plane in an attitude with the rear parts 14B and 40B facing vertically downward (hereinafter also referred to as a “third attitude”), the longitudinal direction of the heater housing 60 is substantially orthogonal to the horizontal plane.

The controller 80 is housed in the lower end of the handle housing 12. In this embodiment, the controller 80 is housed directly above the battery mounting part 40. The controller 80 is formed by a computer that includes a CPU as a processor, a memory such as a RAM and a ROM, and a timer. The controller 80 supplies power from the battery BT to the blower part 30 and the heating element 70. The controller 80 receives control signals from the switch 24 and the operating part 18 and supplies power to the blower part 30 and the heating element 70 according to the received signal.

The operating part 18 is arranged on an upper part of the blower housing 14. The operating part 18 is a switch group for adjusting the temperature and air volume of the air flow blown from the heat gun 100. A user can adjust, for example, the air volume and temperature of the air flow, by operating the switch group of the operating part 18. The maximum air volume of the heat gun 100 of this embodiment can be adjusted, for example, up to 200 L/min, which is larger than 100 L/min that is one example of the maximum air volume of a conventional product. The maximum air temperature of the heat gun 100 of this embodiment can be adjusted to 600° C. or higher, which is higher than 550° C. that is one example of the maximum air temperature of a conventional product. The air volume and temperature are set with the operating part 18 and outputted to the controller 80.

As shown in FIGS. 2 and 3, the heat gun 100 of this embodiment has the blower part 30, the heating element 70, the heater housing 60 for housing the heating element 70, and the detachment mechanism 50.

The blower part 30 has the motor 32, a fan 34 and an inner housing 36. The motor 32 is, for example, a brushless DC motor. As shown in FIG. 3, the motor 32 is housed substantially in the center of the blower housing 14. Power is supplied from the battery BT to the motor 32 via the controller 80.

The motor 32 includes a motor body part 320 including a stator and a rotor, and a motor shaft 322. In this embodiment, a rotational axis RX of the motor shaft 322 is substantially parallel to the longitudinal direction of the heater housing 60. Thus, the rotational axis RX of the motor shaft 322 extends in the front-rear direction. The fan 34 is fixed to a front end part of the motor shaft 322. The rotational axis of the motor shaft 322 may cross or orthogonally cross the longitudinal direction of the heater housing 60.

The fan 34 is, for example, a centrifugal fan, and is rotated by rotational driving of the motor 32. The fan 34 generates air flow by integrally rotating with the motor shaft 322.

The inner housing 36 is fixed to the inside of the blower housing 14, and houses the motor 32 and the fan 34. The inner housing 36 has a generally circular cylindrical shape elongate in the front-rear direction. A front end 36F of the inner housing 36 defines an opening. The opening of the front end 36F of the inner housing 36 communicates with a rear end opening of the heater housing 60. An inner surface of the inner housing 36 defines a flow passage 38 through which air flow generated by the fan 34 is led to the heater housing 60.

As shown in FIG. 3, the heater housing 60 is connected to a front end of the blower part 30. The heater housing 60 includes a body 62, a flow passage 64 and the outlet 66.

The body 62 defines an outer shell of the heater housing 60. The body 62 has a cylindrical shape (in this embodiment, a circular cylindrical shape) extending in the front-rear direction. The body 622 includes a steel pipe 622 and a mica pipe 624. The mica pipe 624 is disposed between the heating element 70 and the steel pipe 622 and restrains or prevents heat transfer from the heating element 70 to the steel pipe 622.

An inner surface of the body 62 defines the flow passage 64 through which air flow is led forward within the heater housing 60. A rear end opening of the body 62 communicates with the opening of the front end 36F of the inner housing 36, and air flow is led in from the flow passage 38 of the blower part 30 through this opening. An opening of a front end part 60F of the body 62 communicates the flow passage 64 with the outside and serves as the outlet 66 from which the air flow of the flow passage 64 is blown to the outside. The heating element 70 is arranged in the flow passage 64.

As shown in FIG. 4, the heating element 70 has support bodies 72 and heater bodies 76. Each of the support bodies 72 is a columnar ceramic extending in the longitudinal direction of the heater hosing 60. A groove 74 is formed on an outer surface of the support body 72 in the radial direction. The number of the grooves 74 corresponds to the number of the heater bodies 76. In this embodiment, eight grooves 74 are provided, and the heater bodies 76 are respectively arranged in the eight grooves 74. The support bodies 72 gather and store heat generated from the heater bodies 76.

Each of the heater bodies 76 is formed of a heating wire that generates heat by energization. Power from the battery BT is supplied to the heater body 76 via the controller 80, and the heater body 76 then generates heat at a high temperature, for example, 600° C. or higher.

The heater body 76 is formed in a circular cylindrical shape by spirally winding the heating wire. The heater body 76 having a circular cylindrical shape allows air flow to easily pass therethrough. Thus, the passage resistance inside the heater housing 60 is reduced, and reduction of the air volume of the air flow from the outlet 66 is restrained or prevented. Further, the surface area of the heater body 76 in contact with the air flow is increased, so that the heat generated from the heater body 76 is efficiently transferred.

The air supplied from the blower part 30 is heated to a high temperature by the heating element 70 when passing through the flow passage 64 inside the heater housing 60. The heated air is led forward from the outlet 66 of the front end part 60F of the heater housing 60 to the outside. The maximum temperature of the air flow blown from the outlet 66 is 600° C. or higher. The temperature of the air flow blown from the outlet 66 can be obtained, for example, by measuring the temperature of the outlet 66 or a member provided in the outlet 66 by using a thermometer, a thermocouple, a temperature sensor or other various methods, during driving of the heat gun 100.

As shown in FIG. 2, a radially outer surface of the front end part 60F of the heater housing 60 is configured such that a nozzle attachment 90 is fitted thereon.

The nozzle attachment 90 is provided to change the direction of the air flow blown from the outlet 66. The nozzle attachment 90 has various shapes corresponding to applications for heat treatment by the heat gun 100. In FIG. 2, an example of the nozzle attachment 90 is shown having a generally circular cylindrical shape having a front opening and a rear opening larger than the front opening. The shape of the nozzle attachment 90 is not limited to this, but can be appropriately replaced with the nozzle attachment 90 having a suitable shape for the intended use of the heat gun 100.

The inner diameter of the rear end opening of the nozzle attachment 90 is substantially equal to the outer diameter of the front end part 60F of the heater housing 60. The nozzle attachment 90 is fitted onto the heater housing 60, for example, by press fitting. The nozzle attachment 90 is held on the front end part 60F of the heater housing 60 by frictional force strong enough to prevent slipping off the heater housing 60. In the heat gun 100 of this embodiment, the nozzle attachment 90 can be detached from the heat gun 100 in a simple manner using the detachment mechanism 50.

A2. Air flow path in the heat gun 100:

In FIG. 3, a flow path FL of air flowing within the heat gun 100 is shown by solid arrow. FIG. 3 conceptually shows the flow path FL, and does not accurately show the flow path of air flow within the heat gun 100. Further, the air flow path is not limited to that shown in FIG. 3.

When a user manually depresses the trigger 26, the motor 32 is driven and the fan 34 is rotated. When the fan 34 is rotated, outside air is led into the flow passage 38 of the inner housing 36 from the inlet 142. The air led in from the outside forms air flow and passes through the flow passage 38. The air flow flowing through the flow passage 38 passes through the inside and the periphery of the motor 32 and is led into the flow passage 64 of the body 62 of the heater housing 60.

The air flow flowing through the flow passage 64 is heated by passing through the periphery of the heating element 70 disposed in the flow passage 64, and blown to the outside from the outlet 66 formed in the front end part 60F of the heater housing 60. Where the nozzle attachment 90 is attached to the front end part 60F, the air flow is supplied to the inside of the nozzle attachment 90 through the outlet 66 and blown to the outside from the front end opening of the nozzle attachment 90.

A3. The structure of the detachment mechanism 50:

The structure of the detachment mechanism 50 is now described with reference to FIGS. 3 and 5 to 10. As shown in FIG. 3, the detachment mechanism 50 is held in the front end opening 144 of the blower housing 14.

The detachment mechanism 50 is configured to be movable relative to the heater housing 60 in the front-rear direction. In FIG. 3, the detachment mechanism 50 is shown in an initial position in which the detachment mechanism 50 is located at the rearmost position (rearmost end).

The nozzle attachment 90 can be detached from the heater housing 60 by sliding the detachment mechanism 50 forward from the initial position. The nozzle attachment 90 can be detached in a simple manner by using the detachment mechanism 50, so that the detachment mechanism 50 is also referred to as a quick release mechanism. The detachment mechanism 50 is arranged radially outside of the heating element 70 and the heater housing 60, and also serves as a cover for covering the circumferences of the heating element 70 and the heater housing 60.

As shown in FIGS. 3 and 5, the detachment mechanism 50 has an inner cover part 52, an outer cover part 54 and a push-out part 58. The inner cover part 52 has a cylindrical shape corresponding to the heater housing 60. Specifically, the inner cover part 52 has a generally circular cylindrical shape elongate in the longitudinal direction of the heater housing 60. As shown in FIG. 3, the inner cover part 52 is arranged radially outside of the heater housing 60 so as to cover at least part of the heater housing 60. In the example shown in FIG. 3, the inner cover part 52 covers from the vicinity of a rear end to the vicinity of a front end of the heater housing 60. The inner cover part 52 is formed of a material having a low thermal conductivity such as a resin material, and restrains or prevents heat transfer from the heater housing 60 to the outside.

As shown in FIG. 3, the push-out part 58 is fixed to an inner surface 521 of the inner cover part 52. The push-out part 58 is a metal member having a generally circular cylindrical shape corresponding to the outer shape of the heater housing 60. The push-out part 58 is fastened to a projection 52P (see FIG. 10) formed on the inner surface 521 of the inner cover part 52. Thus, the push-out part 58 is integrally moved with the inner cover part 52 by user's operation of the detachment mechanism 50. The push-out part 58 has an inner diameter slightly larger than the outer diameter of the heater housing 60. Thus, the push-out part 58 is moved in the front-rear direction along the outer surface of the heater housing 60.

When the detachment mechanism 50 is operated to move the inner cover part 52 forward as shown in FIG. 6, a front end 58F of the push-out part 58 abuts on a rear end of the nozzle attachment 90 fitted onto the front end part 60F of the heater housing 60. The front end 58F of the push-out part 58 pushes out the rear end of the nozzle attachment 90 forward relative to the heater housing 60 against the frictional force between the nozzle attachment 90 and the heater housing 60. As a result, the nozzle attachment 90 is detached from the heater housing 60.

As shown in FIG. 5, a spiral guide groove 528 is formed in the vicinity of a rear end of an outer surface 522 of the inner cover part 52. The guide groove 528 is threadedly engaged in a slidable manner with a spiral guide projection 148 (see FIG. 6) formed in the vicinity of the opening 144 of the blower housing 14.

When the inner cover part 52 is turned in a counterclockwise direction when the heat gun 100 is viewed from the front in the front-rear direction, the guide projection 148 is spirally slid along the guide groove 528. As a result, the inner cover part 52 is moved forward along the longitudinal direction of the heater housing 60 while turning relative to the heater housing 60. When the inner cover part 52 is turned in a clockwise direction relative to the heater housing 60, the guide projection 148 is spirally slid in a reverse direction along the guide groove 528. As a result, the inner cover part 52 is moved rearward along the longitudinal direction of the heater housing 60.

In this embodiment, a front end of the blower housing 14 is connected to a rear end of the inner cover part 52 via a coil spring (not shown). When the inner cover part 52 is located in the initial position, the coil spring is compressed. When the inner cover part 52 is moved forward by operating the detachment mechanism 50, the inner cover part 52 is moved forward against the biasing force of the coil spring. Thus, the coil spring applies a biasing force for returning the inner cover part 52 to the initial position, to the inner cover part 52 placed forward of the initial position. With this configuration, the inner cover part 52 moved forward by operating the detachment mechanism 50 can be easily moved back to the initial position. Further, when the detachment mechanism 50 is used, excessive forward movement of the inner cover part 52 is restrained or prevented by the biasing force for returning the inner cover part 52 to the initial position being applied to the inner cover part 52. Thus, the inner cover part 52 is prevented from slipping off the heater housing 60.

The outer cover part 54 is an outermost layer of the detachment mechanism 50 and serves as an operation part for operating the detachment mechanism 50. Where the grip part 20 of the handle housing 12 is defined as a first grip part, the outer cover part 54 also serves as a second grip part configured to be held by a user. Where the heat gun 100 does not have the detachment mechanism 50, the outer cover part 54 only serves as the second grip part.

As shown in FIGS. 3 and 5, the outer cover part 54 has a generally circular cylindrical shape elongate in the longitudinal direction of the heater housing 60. The outer cover part 54 is arranged radially outside of the inner cover part 52 so as to cover at least part of the inner cover part 52. In this embodiment, the outer cover part 54 is a separate and independent member from the body housing 10 and is arranged apart from the body housing 10.

As shown in FIGS. 3 and 5, the outer cover part 54 is apart from the inner cover part 52. A front opening 540F is formed in a front end 54F of the outer cover part 54 and defined by the front end 54F of the outer cover part 54 and the outer surface 522 of the inner cover part 52. A rear opening 540B is formed in a rear end 54B of the outer cover part 54 and defined by the rear end 54B of the outer cover part 54 and the outer surface 522 of the inner cover part 52.

A through-opening 53 is defined between the outer cover part 54 and the inner cover part 52. The through-opening 53 is a space defined between the outer surface 522 of the inner cover part 52 and an inner surface 541 of the outer cover part 54. The through-opening 53 extends from the front opening 540F to the rear opening 540B. An air layer is formed between the outer cover part 54 and the inner cover part 52, so that heat transfer from the inner cover part 52 to the outer cover part 54 is restrained or prevented. Further, the outer cover part 54 and the inner cover part 52 are easily air-cooled by provision of the through-opening 53 between the outer cover part 54 and the inner cover part 52. Thus, the temperature rise of the outer cover part 54 and the inner cover part 52 is efficiently restrained or prevented.

As shown in FIG. 7, in this embodiment, the outer cover part 54 is connected to the inner cover part 52 via connection parts 55. The connection parts 55 connect the outer surface 522 of the inner cover part 52 and the inner surface 541 of the outer cover part 54. The outer cover part 54 is held on the inner cover part 52 apart from the inner cover part 52 via the connection parts 55. Thus, the outer cover part 54 is connected to the inner cover part 52 with a simple structure. Further, a user can suitably operate the detachment mechanism 50 by operating the outer cover part 54, to which heat is little transferred from the heater housing 60, instead of the inner cover part 52 close to the heater housing 60.

As shown in FIGS. 3 and 5, in this embodiment, the outer cover part 54 has a projection 56 protruding radially outward from an outer surface 542 of the outer cover part 54. The projection 56 has a larger diameter than the other parts of the outer cover part 54. The projection 56 is formed in the vicinity of the front end 54F on a peripheral part of the outer surface 542 of the outer cover part 54. The projection 56 serves as a slip stopper when the outer cover part 54 is held by a user. Thus, the user can easily hold the outer cover part 54 and suitably operate the detachment mechanism 50.

As shown in FIG. 7, in this embodiment, each of the connection parts 55 is a plate-like member elongate in the front-rear direction. A thickness TH1 of the connection part 55 is smaller than a radial thickness TH2 of the outer cover part 54. This configuration efficiently restrains or prevents heat transfer from the inner cover part 52 to the outer cover part 54 via the connection part 55. The thickness TH1 may further be smaller than a radial thickness TH3 of the inner cover part 52. The thickness TH1 of the connection part 55 means a thickness in a circumferential direction orthogonal to the radial direction. The thickness TH1 may be a maximum or average value of the thickness of the connection part 55. The thicknesses TH2 and TH3 may be maximum or average values of the thicknesses of the outer cover part 54 and the inner cover part 52, respectively. In this embodiment, the projection 56 is not included in the thickness TH2, but may be included in the thickness TH2.

As shown in FIG. 7, in this embodiment, the outer cover part 54 and the inner cover part 52 are connected via four connection parts 55. In FIG. 7, a center CP of the heater housing 60 is shown when the detachment mechanism 50 is viewed from the front. The center CP means a center of the outer shape of the heater housing 60 in front view. In this embodiment, the rotational axis RX of the motor shaft 322 and a central axis of the heater housing 60 pass through the center CP.

The four connection parts 55 partition the through-opening 53 into four upper, lower, left and right regions when the detachment mechanism 50 is viewed from the front. Specifically, the four connection parts 55 partition the through-opening 53 into a first through-opening 53A including a region RA directly above the center CP, a second through-opening 53B including a region RB directly below the center CP, a third through-opening 53C including a region RC to the right of the center CP, and a fourth through-opening 53D including a region RD to the left of the center CP.

In heat treatment by the heat gun 100, the heat gun 100 can be used in various attitudes. When holding the grip part 20 and using the heat gun 100, the user often holds the heat gun 100 in an attitude (hereinafter referred to as a normal attitude) in which the extending direction of the grip part 20 extends in the vertical direction, and the blower part 30 and the heating element 70 are placed above the grip part 20 in the vertical direction, and the rotational axis RX of the motor shaft 322 extends substantially in the horizontal direction.

In the heat gun 100 of this embodiment, the first through-opening 53A is formed in the region RA directly above the heater housing 60 that is a heat source. In other words, the connection parts 55 are arranged avoiding the region RA directly above the heater housing 60. This restrains or prevents heat transfer from the heater housing 60 and the inner cover part 52 to the connection parts 55 when the heat gun 100 is used in the normal attitude. Thus, the temperature rise of the outer cover part 54 is more efficiently restrained or prevented.

In heat treatment on an object located at a low position, the heat gun 100 may be used in an attitude (hereinafter referred to as a reverse attitude) in which the heat gun 100 is turned upside down relative to the normal attitude. Specifically, in the reverse attitude, the extending direction of the grip part 20 extends in the vertical direction, and the blower part 30 and the heating element 70 are placed below the grip part 20 in the vertical direction, and the rotational axis RX of the motor shaft 322 extends substantially in the horizontal direction.

In the heat gun 100 of this embodiment, the second through-opening 53B is formed in the region RB directly below the heater housing 60. This more efficiently restrains or prevents heat transfer from the heater housing 60 and the inner cover part 52 to the outer cover part 54 via the connection parts 55 when the heat gun 100 is used in the reverse attitude.

Further, in the heat gun 100 of this embodiment, the third through-opening 53C is formed in the right region RC to the right of the heater housing 60. This more efficiently restrains or prevents heat transfer from the heater housing 60 and the inner cover part 52 to the outer cover part 54 via the connection parts 55 when the heat gun 100 is used in the second attitude.

In the heat gun 100 of this embodiment, the fourth through-opening 53D is formed in the left region RD to the left of the heater housing 60. This more efficiently restrains or prevents heat transfer from the heater housing 60 and the inner cover part 52 to the outer cover part 54 via the connection parts 55 when the heat gun 100 is used in the first attitude.

The through-opening 53 is arranged not to overlap with the body housing 10 in the front-rear direction. In FIG. 8, regions R1, R2, R3, R4 in which the through-opening 53 does not overlap with the body housing 10 are shown by hatching when the heat gun 100 is viewed from the front. In the regions R1, R2, R3, R4 shown in FIG. 8, no object exists in the front-rear direction. In this embodiment, the through-openings 53B, 53C and 53D except for the first through-opening 53A are arranged to include the regions R1, R2, R3, R4 that do not overlap with the body housing 10. A rear opening 540B of the through-opening 53 is avoided from being closed by the body housing 10, so that air easily passes through the through-opening 53. Thus, the effect of air-cooling the outer cover part 54 and the inner cover part 52 by provision of the through-opening 53 is improved.

In FIG. 9, a distance CL between the outer surface 522 of the inner cover part 52 and the inner surface 541 of the outer cover part 54 is shown. The distance CL is a height of the through-opening 53 in the radial direction, and also a length of the connection parts 55 in the radial direction. The distance CL can also be referred to as a separation distance from the inner cover part 52 to the outer cover part 54. In this embodiment, the distance CL is 5 mm or more. Provision of the distance CL of 5 mm or more ensures the thickness of the air layer between the inner cover part 52 and the outer cover part 54, and thus effectively restrains or prevents heat transfer from the inner cover part 52 to the outer cover part 54.

The distance CL can be calculated with a numerical expression: CL=(W2−W1)·(½), where W2 is the maximum width of the contour (the inner diameter) of the inner surface 541 of the outer cover part 54 and W1 is the maximum width of the contour of the outer surface 522 of the inner cover part 52. In this embodiment, the inner cover part 52 and the outer cover part 54 both have a generally circular cylindrical shape. Thus, the maximum width of the contour of the inner surface 541 of the outer cover part 54 corresponds to the maximum value of the inner diameter of the outer cover part 54, and the maximum width of the contour of the outer surface 522 of the inner cover part 52 corresponds to the maximum value of the outer diameter of the inner cover part 52.

In this embodiment, the ratio of a width W3 to the width W1 is 125% or more, where the width W3 is the maximum width of the contour of the outer surface 542 of the outer cover part 54. The maximum width of the contour of the outer surface 542 of the outer cover part 54 corresponds to the maximum value of the outer diameter of the outer cover part 54. The configuration having a sufficient distance from the outer surface 522 of the inner cover part 52 to the outer surface 542 of the outer cover part 54 effectively restrains or prevents heat transfer from the inner cover part 52 to the outer cover part 54. The widths W1, W2, W3 may be minimum or average values of the widths, instead of the maximum widths, respectively. In this embodiment, the projection 56 is not included in the width W3, but it may be included in the width W3.

The front end 54F of the outer cover part 54 is arranged rearward of a front end 52F of the inner cover part 52. Thus, a line SL connecting the front end 54F of the outer cover part 54 and the front end 52F of the inner cover part 52 is inclined in the front-rear direction. In other words, the detachment mechanism 50 is configured to have an outer shape having a diameter decreasing forward. With this configuration, the vicinity of the outlet 66 of the heat gun 100 is reduced in diameter, compared with a configuration in which the front end 52F of the inner cover part 52 is flush with the front end 54F of the outer cover part 54. Thus, the vicinity of the outlet 66 of the heat gun 100 does not easily come into contact with an object to be heat treated. Further, the vicinity of the outlet 66 of the heat gun 100 can be inclined to a horizontal plane during heat treatment. Thus, the workability is improved in the vicinity of the object to be heat treated with the heat gun 100.

As shown in FIG. 9, a length 54L of the outer cover part 54 in the front-rear direction is shorter than a length 52L of the inner cover part 52 in the front-rear direction. Thus, a part of the inner cover part 52 is exposed to the outside without being covered by the outer cover part 54, so that the effect of air-cooling the inner cover part 52 is improved.

As described above, the front end 54F of the outer cover part 54 is arranged rearward of the front end 52F of the inner cover part 52. Further, the rear end 54B of the outer cover part 54 is arranged forward of a rear end 52B of the inner cover part 52. The outer cover part 54 thus covers a prescribed range between the front end 52F and the rear end 52B of the inner cover part 52 in the front-rear direction.

The length 54L of the outer cover part 54 is preferably one third or more, and more preferably a half or more, of the length 52L of the inner cover part 52. With this configuration, the user can easily hold the outer cover part 54 and suitably operate the detachment mechanism 50, while heat transfer from the inner cover part 52 to the outer cover part 54 is restrained or prevented.

In FIG. 10, a region S1 and a region S2 that are respectively occupied by the heating element 70 and the outer cover part 54 are shown when the heat gun 100 is viewed from above. A region S3 in which the region S1 and the region S2 overlap with each other is also shown. For ease of understanding, the regions S1 and S2 are shown hatched, and the region S3 is shown cross-hatched. The region S1 occupied by the heating element 70 means a region occupied by members that heat air flow within the heater housing 60. In this embodiment, the region S1 is a region occupied by the support bodies 72 and the heater bodies 76. In FIG. 10, the detachment mechanism 50 is placed at the rear end initial position.

As shown in FIG. 10, the region S3 is configured to have a half or more of the area of the region S1. Thus, the outer cover part 54 overlaps with a half or more of the region of the heating element 70 when the heat gun 100 is viewed from above. In the heat gun 100 of this embodiment, the provision of the through-opening 53 restrains or prevents heat transfer from the inner cover part 52 to the outer cover part 54. Thus, the area of the outer cover part 54 overlapping with the heating element 70 can be increased as compared with a conventional one. By provision of the outer cover part 54 covering a half or more of the inner cover part 52, a user is prevented from touching the inner cover part 52 and allowed to easily hold the detachment mechanism 50, so that the workability of the heat gun 100 is improved.

When the detachment mechanism 50 is moved forward to a position to detach the nozzle attachment 90, the front end 54F of the outer cover part 54 is located rearward of a front end of the heating element 70. Thus, the outer cover part 54 overlaps with a half or more of the region of the heating element 70 even when the detachment mechanism 50 is moved to a front end position. It may however be configured such that the outer cover part 54 overlaps with a half or more of the region of the heating element 70 only when the detachment mechanism 50 is located in the initial position.

As described above, the heat gun 100 of this embodiment has the outer cover part 54 that is arranged radially outside of the inner cover part 52 so as to be apart from the inner cover part 52 and covers part of the inner cover part 52. The through-opening 53 is defined between the outer cover part 54 and the inner cover part 52 and extends from the front opening 540F of the front end 54F of the outer cover part 54 to the rear opening 540B rearward of the front end 54F of the outer cover part 54. The air layer formed between the outer cover part 54 and the inner cover part 52 restrains or prevents heat transfer from the inner cover part 52 to the outer cover part 54. Further, the outer cover part 54 and the inner cover part 52 are easily air-cooled by provision of the through-opening 53. Thus, heat is not easily transferred from the heating element 70 to the outer cover part 54 and the temperature rise of the outer cover part 54 is restrained or prevented.

The heat gun 100 of this embodiment has the connection parts 55 that connect the outer surface 522 of the inner cover part 52 and the inner surface 541 of the outer cover part 54 and define the through-opening 53 together with the outer cover part 54 and the inner cover part 52. The outer cover part 54 is arranged radially outside of the inner cover part 52 in a simple manner by connecting the outer cover part 54 and the inner cover part 52 via the connection parts 55. By connecting the outer cover part 54 and the inner cover part 52 via the connection parts 55, the inner cover part 52 can be operated via the outer cover part 54. Thus, the detachment mechanism 50 can be operated by operating the outer cover part 54 instead of the inner cover part 52, so that the convenience of the heat gun 100 is improved.

B. Other Embodiments

(B1) In the above-described first embodiment, the outer cover part 54 and the inner cover part 52 are connected via the four connection parts 55, but the number of the connection parts 55 is not limited to four, and any number of (one or more) connection parts 55 may be provided as shown below.

FIG. 11 shows an example in which the outer cover part 54 and the inner cover part 52 are connected via two connection parts 55. In the example shown in FIG. 11, the two connection parts 55 are arranged to the left and right of the center CP, respectively, when the detachment mechanism 50 is viewed from the front. Thus, the two connection parts 55 partition the through-opening 53 into a through-opening 53E including the region RA directly above the center CP and a through-opening 53F including the region RB directly below the center CP. The through-openings 53E and 53F are examples of the “first through-opening” and the “second through-opening”, respectively. Like this example, a third through-opening including the region RC to the right of the center CP and a fourth through-opening including the region RD to the left of the center CP may be omitted, but this is not limitative. For example, only either one of the third and fourth through-openings may be defined. The two connection parts 55 may be arranged above and below the center CP of the heater housing 60, respectively.

FIG. 12 shows an example in which the outer cover part 54 and the inner cover part 52 are connected via three connection parts 55. In the example shown in FIG. 12, the three connection parts 55 are arranged to the upper right side and the upper left side of the center CP and directly below the center CP when the detachment mechanism 50 is viewed from the front. Thus, the three connection parts 55 partition the through-opening 53 into a through-opening 53G including the region RA directly above the center CP, a through-opening 53H including the region RC to the right of the center CP, and a through-opening 53I including the region RD to the left of the center CP. The through-openings 53G, 53H and 53I are examples of the “first through-opening”, the “third through-opening” and the “fourth through-opening”, respectively. Like this example, only either one of the first and second through-openings may be provided.

FIG. 13 shows an example in which the outer cover part 54 and the inner cover part 52 are connected via one connection part 55. The connection part 55 is arranged only directly below the center CP. Thus, the connection part 55 defines one through-opening 53J together with the outer cover part 54 and the inner cover part 52. The through-opening 53J includes the region RA directly above the center CP, the region RC to the right of the center CP, and the region RD to the left of the center CP. The through-opening 53J is an example of the “first through-opening”, the “third through-opening” and the “fourth through-opening”. Like this example, only one through-opening 53 may be defined. The one through-opening 53 may be defined to include regions above and below the center CP and to the left and right of the center CP.

(B2) In the first embodiment, the outer cover part 54 and the inner cover part 52 are connected via the connection parts 55, but the heat gun 100 may not have the connection parts 55. In this case, the outer cover part 54 may be arranged apart from the inner cover part 52 so as to cover at least part of the inner cover part 52, for example, by being connected to the body housing 10. In this case, the outer cover part 54 may be integrally formed with the body housing 10.

(B3) In the first embodiment, the heat gun 100 has the detachment mechanism 50, but it may not have the detachment mechanism 50. In this case, the inner cover part 52 may be fixed to the opening 144 of the blower housing 14, or integrally formed with the body housing 10. The outer cover part 54 may be connected to the inner cover part 52 via the connection parts 55. In a structure having no connection parts 55, the outer cover part 54 may be directly connected to the body housing 10. In this case, the outer cover part 54 may be integrally formed with the body housing 10.

(B4) In the first embodiment, the rotational axis RX of the motor shaft 322 is substantially parallel to the longitudinal direction of the heater housing 60 (more specifically, the longitudinal direction of the body 62), but the rotational axis RX may cross or orthogonally cross the longitudinal direction.

(B5) In the first embodiment, the outer cover part 54, the inner cover part 52, the push-out part 58 and the heater housing 60 all have a generally circular cylindrical shape elongate in the longitudinal direction of the heater housing 60, but at least any one of these members may have a cylindrical shape other than the circular cylindrical shape. For example, the sectional shape of at least any one of these members in a direction orthogonal to the longitudinal direction may be various geometrical shapes other than a circular shape, including a triangular, rectangular, pentagonal, hexagonal, octagonal or other polygonal shape, or it may be an elliptical or oval shape. The outer cover part 54 and the inner cover part 52 may be of any shape, provided that their function as a cover for covering the circumferences of the heating element 70 and the heater housing 60 is secured. The sectional shapes of the outer cover part 54, the inner cover part 52, the push-out part 58 and the heater housing 60 may not conform to each other, but their sectional shapes may conform to each other in any combination of these members. In a structure in which the outer cover part 54, the inner cover part 52 and the push-out part 58 have the function of the detachment mechanism 50, it is preferable that at least the push-out part 58 has a shape conforming to the outer shape of the heater housing 60.

In a structure in which the heater housing 60 has a sectional shape other than a circular shape, the center CP of the heater housing 60 may be a center of gravity of the sectional shape of the heater housing 60. The center CP of the heater housing 60 may be an intersection of a first line parallel to the left-right direction at a position where the width of the sectional shape of the heater housing 60 in the left-right direction is at the maximum, and a second line parallel to the up-down direction at a position where the width (height) of the sectional shape of the heater housing 60 in the up-down direction is at the maximum.

Correspondences between the features of the above-described embodiments and the features of the present disclosure are as follows. The features of the above-described embodiments are merely exemplary and do not limit the features of the present disclosure.

The heat gun 100 is an example of the “heat gun”. The motor 32 is an example of the “motor”. The fan 34 is an example of the “fan”. The heating element 70 is an example of the “heating element”. The heater housing 60 is an example of the “heater housing”. The body 62 is an example of the “body”. The longitudinal direction of the heater housing 60 and the longitudinal direction of the body 62 are examples of the “longitudinal direction”. The flow passage 64 is an example of the “flow passage”. The outlet 66 is an example of the “outlet”. The inner cover part 52 is an example of the “inner cover part”. The outer cover part 54 is an example of the “outer cover part”. The through-opening 53 is an example of the “through-opening”. The first through-opening 53A, the second through-opening 53B, the third through-opening 53C and the fourth through-opening 53D are examples of the “first through-opening”, the “second through-opening”, the “third through-opening” and the “fourth through-opening”, respectively. The grip part 20 is an example of the “grip part”. The connection part 55 is an example of the “connection part”. The body housing 10 is an example of the “body housing”. The length 52L and the length 54L are examples of the “length of the inner cover part” and the “length of the outer cover part”, respectively. The front end 52F and the front end 54F are examples of the “front end of the inner cover part” and the “front end of the outer cover part”, respectively. The projection 56 is an example of the “projection”. The push-out part 58 is an example of the “push-out part”. The length L1 is an example of the “maximum length in the front-rear direction”. The battery BT is an example of the “battery”. The battery mounting part 40 is an example of the “battery mounting part”.

Further, in view of the nature of the present disclosure and the above-described embodiments and the modifications thereto, the following aspects are provided. At least one of the aspects can be employed in combination with at least one of the above-described embodiments and modifications and the claimed invention.

(Aspect 1) A thickness of the connection part in a direction orthogonal to the radial direction is smaller than a thickness of the outer cover part in the radial direction.

The thickness TH1 and the thickness TH2 of the above-described embodiment are examples of the “thickness of the connection part” and the “thickness of the outer cover part in the radial direction” in this aspect, respectively.

This configuration efficiently restrains or prevents heat transfer from the inner cover part to the outer cover part via the connection part. Further, the volume of the air layer between the inner cover part and the outer cover is increased, so that heat transfer from the inner cover part to the outer cover part is more efficiently restrained or prevented.

The present disclosure is not limited to any of the above-described embodiments but may be implemented by a diversity of configurations without departing from the scope of the disclosure. For example, the technical features of any of the above embodiments may be replaced or combined appropriately, in order to solve part or all of the problems described above or in order to achieve part or all of the advantageous effects described above. Any of the technical features may be omitted appropriately unless the technical feature is described as essential in the description hereof.

DESCRIPTION OF THE NUMERALS

10: body housing, 12: handle housing, 14: blower housing, 14B: rear part, 14L: left part, 14R: right part, 18: operating part, 20: grip part, 24: switch, 26: trigger, 28: lock-on button, 30: blower part, 32: motor, 34: fan, 36: inner housing, 36F: front end, 38: flow passage, 40: battery mounting part, 40B: rear part, 40L: left part, 40R: right part, 42: terminal, 44: guide groove, 50: detachment mechanism, 52: inner cover part, 52B: rear end, 52F: front end, 52P: projection, 53, 53E, 53F, 53F, 53G, 53H, 53I, 53J: through-opening, 53A: first through-opening, 53B: second through-opening, 53C: third through-opening, 53D: fourth through-opening, 54: outer cover part, 54B: rear end, 54F: front end, 55: connection part, 56: projection, 58: push-out part, 58F: front end, 60: heater housing, 60F: front end part, 62: body, 64: flow passage, 66: outlet, 70: heating element, 72: support body, 74: groove, 76: heater body, 80: controller, 90: nozzle attachment, 100: heat gun, 142: inlet, 144: opening, 148: guide projection, 320: motor body, 322: motor shaft, 521: inner surface, 522: outer surface, 528: guide groove, 540B: rear opening, 540F: front opening, 541: inner surface, 542: outer surface, 622: steel pipe, 624: mica pipe, BT: battery, CP: center, FL: flow path, RX: rotational axis