A Compressor Unit for Vehicle

Description

TECHNICAL FIELD

The present disclosure relates to the technical field of air compressors for use in vehicles such as commercial vehicles or railcars, and in particular to external heat insulation for preventing oil emulsification of a volumetric air compressors intended for these applications.

BACKGROUND

During the operation of a vehicle, the outside air flow will take away a lot of temperature from the compressor, or in a low temperature environment, the internal temperature of the compressor cannot rise fast enough, so that the internal temperature of the compressor is too low, and the moisture of the sucked-in air condenses in the internal parts of the compressor and mixes with the oil, resulting in the phenomenon of oil emulsification, which is a serious danger for the compressor, as lubrication cannot be carried out and corrosion will occur.

In order to solve the above-mentioned problems, it is an object of the present disclosure to propose an external heat insulation for preventing oil emulsification in a volumetric air compressor.

SUMMARY

The purpose of this part is to summarize some aspects of the embodiments of the present disclosure as well as to briefly describe some preferred embodiments. Simplifications or omissions may be made in this part, as well as in the summary of the specification and the disclosure title of this application, to avoid obscuring the purpose of this part, the summary of the specification, and the disclosure title, and such simplifications or omissions are not to be used to limit the scope of the present disclosure.

In view of the problems in the prior art, the present disclosure is proposed.

Accordingly, it is an object of the present disclosure to provide an external protective covering member used as a heat insulation for preventing oil emulsification in a volumetric air compressor. The external protective covering member also prevents contamination of the air compressor body by sewage, dust, and other road and track dirt while the vehicle is in operation.

In order to solve the above technical problems, according to one aspect of the present disclosure, the present disclosure provides the following technical solution.

A compressor unit for a vehicle, the compressor unit comprising a volumetric air compressor, wherein the compressor unit further comprises an external heat insulation for preventing the condensation of water within the volumetric air compressor, wherein the external heat insulation is provided at least on a surface of the body of the volumetric air compressor.

As a preferred embodiment of the compressor unit for a vehicle as described in the present disclosure, the external heat insulation comprises a protective layer and a heat insulation plate, the protective layer being provided at least on the surface of the body of the volumetric air compressor, and the heat insulation plate being provided in the gap between the protective layer and the body of the volumetric air compressor.

As a preferred embodiment of the compressor unit for a vehicle as described in the present disclosure, the body of the volumetric air compressor is mounted at a designated position in the vehicle by means of the external heat insulation.

As a preferred embodiment of the compressor unit for a vehicle as described in the present disclosure, the external heat insulation is provided with openings, the openings being used for one or more of wiring harnesses, pneumatic lines and coolant lines, and/or being used for fixation of the compressor unit.

As a preferred embodiment of the compressor unit for a vehicle as described in the present disclosure, the external heat insulation of the volumetric air compressor is of split type to facilitate maintenance and repair of components of the volumetric air compressor.

As a preferred embodiment of the compressor unit for a vehicle as described in the present disclosure, the external heat insulation comprises a plurality of portions formed separately, the plurality of portions being detachably connected to each other to cover the surface of the body of the volumetric air compressor.

As a preferred embodiment of the compressor unit for a vehicle as described in the present disclosure, the plurality of portions comprises a front portion covering the front end of the volumetric air compressor body, an upper portion covering the upper and side portions of the volumetric air compressor body, and a bottom portion covering the bottom portion of the volumetric air compressor body, wherein the front portion, the upper portion and the bottom portion are formed separately.

As a preferred embodiment of the compressor unit for a vehicle as described in the present disclosure, the external heat insulation is provided with an opening exposing the oil removal cartridge of the volumetric air compressor, and the external heat insulation further comprises a cover adapted to detachably cover the opening.

As a preferred embodiment of the compressor unit for a vehicle as described in the present disclosure, the cover detachably covers the opening by means of a band member.

As a preferred embodiment of the compressor unit for a vehicle as described in the present disclosure, the external heat insulation is provided with a first band fixing hole adjacent to one side of the opening and across the opening with a second band fixing hole on the opposite side of the opening, and that the fasteners pass through the retaining rings at both ends of the band member aligned with the first band fixing hole and the second band fixing hole, respectively, thereby the cover detachably covering the opening.

As a preferred embodiment of the compressor unit for a vehicle as described in the present disclosure, the cover detachably covers the opening by means of fasteners, wherein the fasteners pass through a first fixing hole on the external heat insulation and a second fixing hole on the cover.

As a preferred embodiment of the compressor unit for a vehicle as described in the present disclosure, the external heat insulation is provided with a first protruding portion adjacent to one side of the opening and across the opening with a second protruding portion on the opposite side of the opening, by attaching retaining rings at both ends of a band member to the first protruding portion and the second protruding portion, the cover detachably covers the opening.

As a preferred embodiment of the compressor unit for a vehicle as described in the present disclosure, the cover detachably covers the opening by means of a snap connection.

As a preferred embodiment of the compressor unit for a vehicle as described in the present disclosure, the snap connection comprises resilient snap members provided on the cover and slots provided on the external heat insulation, wherein the resilient snap members of the cover engage the slots of the external heat insulation of the external heat insulation, thereby the cover detachably covering the opening.

As a preferred embodiment of the compressor unit for a vehicle as described in the present disclosure, the snap connection comprises resilient snap members provided on the external heat insulation and slots provided on the cover, wherein the resilient snap members of the external heat insulation engage the slots of the cover, thereby the cover detachably covering the opening.

As a preferred embodiment of the compressor unit for a vehicle as described in the present disclosure, the compressor unit further comprises drive means for driving the volumetric air compressor.

The present disclosure also provides a vehicle wherein the vehicle is mounted with the above-mentioned compressor unit.

As a preferred embodiment of the external heat insulation for preventing oil emulsification of a volumetric air compressor as described in the present disclosure, the volumetric air compressor body is mounted at a designated location in the vehicle by means of the external heat insulation of the air compressor.

As a preferred embodiment of the external heat insulation for preventing oil emulsification of the volumetric air compressor as described in the present disclosure, the external heat insulation of the air compressor is provided with mounting screws and mounting screw holes.

As a preferred embodiment of the external heat insulation for preventing oil emulsification of a volumetric air compressor as described in the present disclosure, the external heat insulation of the air compressor is of a split type, which facilitates the maintenance and upkeep of the parts.

As a preferred embodiment of the external heat insulation for preventing oil emulsification in a volumetric air compressor as described in the present disclosure, the heat insulation panels are connected to each other by clasps.

As a preferred embodiment of the external heat insulation for preventing oil emulsification in a volumetric air compressor as described in this patent, the thermal insulation plates are interconnected by screws and threaded clips.

The beneficial effects of the present disclosure compared to the prior art are:

• • 1. It can effectively prevent the condensation of water at the internal parts of the compressor, so that oil emulsification will not occur. It prevents the compressor body from being contaminated by sewage, dust, and other road and rail dirt while the vehicle is in operation.
  • 2. The split design is easy to maintain. This allows access to the dedicated area of the compressor to replace wearing parts such as filter cartridges without removing the compressor from the vehicle.

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the present disclosure will be described in detail in the following in combination with the accompanying drawings and detailed embodiments, and it will be obvious that the accompanying drawings in the following description are only some of the embodiments of the present disclosure, and for the person of ordinary skill in the field, other accompanying drawings can be obtained according to these drawings without paying creative labor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic diagram of a structure of a compressor unit of the present disclosure.

FIG. 2 illustrates a schematic diagram of the inner cavity structure of the external heat insulation of the compressor unit of the present disclosure.

FIG. 3 illustrates a three-dimensional view of a compressor unit of the present disclosure as viewed from the top.

FIG. 4 illustrates a three-dimensional view of the compressor unit of the present disclosure as viewed from the bottom.

FIG. 5 illustrates a three-dimensional view of the compressor unit of the present disclosure, wherein the cover of the external insulation member is removed.

FIG. 6 illustrates an exploded view of an external heat insulation of the compressor unit of the present disclosure.

FIG. 7 illustrates a three-dimensional view of a first embodiment of a detachable connection of a cover of the external heat insulation of the compressor unit of the present disclosure.

FIG. 8 illustrates a sectional view of details about portions in circles A and B in FIG. 7.

FIG. 9 illustrates a three-dimensional view of a second embodiment of the detachable connection of the cover of the external heat insulation of the compressor unit of the present disclosure, wherein a first state of the external heat insulation of the second embodiment is shown on the top and a second state of the external heat insulation is shown on the bottom.

FIG. 10 illustrates a sectional view of details about portions in circles A and B in FIG. 9.

FIG. 11 illustrates a three-dimensional view of details about a portion in circles C and A in FIG. 9, wherein in A of FIG. 11 the cover of the external heat insulation is removed.

FIG. 12 illustrates a three-dimensional view of a third embodiment of the detachable connection of the cover of the external heat insulation of the compressor unit of the present disclosure.

FIG. 13 illustrates a sectional view of details about portions of circles A and B in FIG. 12.

FIG. 14 illustrates a three-dimensional view of a variation of the third embodiment of the detachable connection of the cover of the external heat insulation of the compressor unit of the present disclosure.

FIG. 15 illustrates a sectional view of details about a portion in circle A in FIG. 14.

DETAILED DESCRIPTION OF THE DRAWINGS

In order to make the above objects, features and advantages of the present disclosure more apparent and understandable, the following description of the specific embodiments of the present disclosure is given in combination with the accompanying drawings.

Many specific details are set forth in the following description in order to fully understand the present disclosure, but the present disclosure can also be implemented in other ways different from those described herein, and thus the present disclosure is not limited by the specific embodiments disclosed below.

Secondly, the present disclosure is described in detail in conjunction with the schematic drawings, and in detailing the embodiments of the present disclosure, for the purpose of illustration, the sectional drawings indicating the structure of the device will not be partially enlarged in accordance with the general scale, and the the schematic drawings are only examples, which shall not limit the scope of protection of the present disclosure herein. In addition, three-dimensional spatial dimensions of length, width, and depth should be included in the actual fabrication.

In order to make the objects, technical solutions and advantages of the present disclosure clearer, embodiments of the present disclosure will be described in further detail below in combination with the accompanying drawings.

The present disclosure provides the following technical solution: an external protective housing (i.e., an external heat insulation) for preventing oil emulsification of a volumetric air compressor. The external heat insulation also prevents contamination of the air compressor body by sewage, dust, and other road or track dirt while the vehicle is in operation.

FIGS. 1 to 2 illustrate a schematic structural diagram of an embodiment of an external heat insulation for preventing oil emulsification of a volumetric air compressor of the present disclosure. The main part of the figures includes a body 1 of a volumetric air compressor, an external heat insulation 2 of the air compressor, mounting slots 3, and a wire opening 4 of the air compressor.

Referring again to FIGS. 1 to 2, the outer wall of the volumetric air compressor body 1 is provided with an external heat insulation 2 of the air compressor. The external heat insulation 2 of the air compressor comprises a heat insulating plate 2-1 and a heat insulating layer 2-2 (i.e., a protective layer 2-2), wherein the protective layer 2-2 is provided on a surface of the volumetric air compressor body 1 and wherein the heat insulating layer 2-1 is provided in the gap between the protective layer 2-2 and the volumetric air compressor body 1. The external heat insulation 2 of the air compressor may be provided with openings (e.g., in the upper side portion, the bottom side portion or the side portions on both sides of the external heat insulation 2), the openings may be used for one or more of the wiring harnesses, the pneumatic lines and the coolant lines and/or may be used for the fixation of the compressor unit. In one embodiment, the openings are shown as mounting slots 3 and a wire opening 4 for the air compressor, but it will be appreciated that other forms of openings may also be used.

Referring again to FIGS. 1 to 2, the volumetric air compressor body 1 is mounted at a designated location in the vehicle by means of an external heat insulation 2 of the air compressor. The external heat insulation 2 of the air compressor is provided with mounting screws and mounting screw holes. The external heat insulation 2 of the air compressor is of a split type, which facilitates maintenance and care of the parts; and the parts of the external heat insulation 2 of the split design can be connected to each other by means of snap fasteners or screws and clips.

The working principle of the external heat insulation 2 in the present disclosure is that the external heat insulation 2 can effectively prevent the generation of oil emulsification during use. It can avoid the contamination of the air compressor body by sewage, dust, etc. during the operation of the vehicle; it can improve the impact resistance of the air compressor, so that the air compressor can work stably under the bad working conditions; it can improve the service life of the air compressor and reduce the maintenance cost.

Reference is made to FIGS. 3 to 5, which illustrate a three-dimensional view of a compressor unit 100 of an embodiment of the present disclosure. The compressor unit 100 includes a volumetric air compressor body 1 and an external heat insulation 2.

The external heat insulation 2 is provided on the volumetric air compressor body 1. The shape of the external heat insulation 2 may be adapted to the shape of the volumetric air compressor body 1, and the external heat insulation 2 surrounds the volumetric air compressor body 1 at least partially or completely around the volumetric air compressor body 1.

The compressor unit 100 may further comprise a drive device 50. The drive device 50 is used to drive the operation of the volumetric air compressor and may be, for example, an electric motor, a hydraulic drive, a gearbox, etc. The drive device 50 is coupled to an end of the volumetric air compressor body 1. In the embodiment, the external heat insulation 2 is shown as not enclosing the drive unit 50, but it is to be understood that the external heat insulation 2 can be designed to enclose the drive unit 50, as well as both the volumetric air compressor body 1 and the drive device 50, as desired.

Referring to FIG. 6, the external heat insulation 2 is of a split design and may comprise a plurality of portions formed separately, the plurality of portions being detachably connected to each other to cover the surface of the volumetric air compressor body 1. The plurality portions may include a front portion 21, an upper portion 22, a bottom portion 23, and a cover 24.

In the present disclosure, the bottom direction is a direction toward the carrying member like a sheet metal plate or a vehicle frame (not shown) for the volumetric air compressor body 1 near the exterior; the upper direction is a direction opposite to the bottom direction; the rear direction is a direction toward an end portion of the volumetric air compressor body 1 coupled to the drive device 50; and the front direction is a direction opposite to the rear direction.

Referring to FIG. 4, the bottom portion 23 is used to cover the bottom of the volumetric air compressor body 1, and to carry the volumetric air compressor body 1 and attach the volumetric air compressor body 1 to the carrier member (not shown). The carrier member is then bolted to the chassis of the vehicle, thereby realizing fixation of the volumetric air compressor body 1 to the vehicle. The bottom portion 23 may be provided with heat insulation fixing holes 231 aligned with air compressor fixing holes (not shown) on the bottom of the volumetric air compressor body 1. The bolts may be passed through the heat insulation fixing holes 231 of the bottom portion 23 and the air compressor fixing holes of the volumetric air compressor body 1, thereby fixing the bottom portion 23 to the bottom of the volumetric air compressor body 1. The bottom portion 23 may also be provided with mounting slots 3. The mounting slots 3 are aligned with the mounting holes (not shown) on the bottom of the volumetric air compressor body 1 and the mounting holes on the carrier member. Connecting parts such as screws, studs, and the like may pass through the mounting holes of the carrier member and the mounting slots 3, and be fastened in the mounting holes of the volumetric air compressor body 1, thereby securing the bottom portion 23 of the external heat insulation 2, the volumetric air compressor body 1, and the carrier member together, wherein the bottom portion 23 of the external heat insulation 2 is disposed between the volumetric air compressor body 1 and the carrier member.

Referring back to FIG. 6, an upper portion 22 is used to cover an upper portion as well as a side portion of the volumetric air compressor body 1, and is used to connect with a bottom portion 23 so as to substantially encircle the volumetric air compressor body 1 to cover the volumetric air compressor body 1. The upper portion 22 has a main body 221 that covers the upper portion of the volumetric air compressor body 1, and two side portions 222 that extend toward the bottom from the two sides of the main body 221. The side portions 222 cover both sides of the volumetric air compressor body 1. The side portions 222 are connected to the bottom portion 23 at a bottom end by means of connection members such as screws or the like.

The front portion 21 is used to cover the front end portion of the volumetric air compressor body 1, the front end portion being an end portion opposite to the end portion where the drive device 50 is coupled to the volumetric air compressor body 1. The front portion 21 is also used to combine with the upper portion 22 and the bottom portion 23 to substantially cover the volumetric air compressor body 1. The two sides of the front portion 21 are connected to the two side portions 222 of the upper portion 22, respectively, by means of connecting members such as screws or the like.

A first notch 213 is provided at the upper edge of the front portion 21. A corresponding second notch 223 is provided at the front edge of the upper portion 22. The combination of the first notch 213 and the second notch 223 can form an opening 25. As shown in FIG. 5, the opening 25 is used to suitably expose the oil removal cartridge 15 of the air compressor after the front portion 21, the upper portion 22, and the bottom portion 23 are coupled together to allow access to the oil removal cartridge 15 through the opening 25. The oil removal cartridge 15 is a component of a volumetric air compressor that needs to be replaced periodically with use.

The cover 24 is adapted to cover the opening 25. The outer contour of the cover 24 may match the inner contour of the opening 25. The cover 24 is detachably coupled to the front portion 21 and the upper portion 22 in a manner that will be detailed below.

The front portion 21 and upper portion 22 may be provided with various opening cut-outs, and the opening cut-outs can be the wire opening 4. The opening cut-outs are used to allow passage of components such as wiring harnesses, pneumatic lines, cooling lines, and the like of the air compressor.

The detachable connection of the cover 24 allows exposing the oil removal cartridge 15 of the air compressor without removing the rest of the external heat insulation 2, thus permitting easy removal and replacement of the oil removal cartridge 15.

In addition, since the front portion 21 and the upper portion 22 are secured to each other or to the bottom portion 23 only by screws, it is possible to easily remove the front portion 21 and the upper portion 22 after simply disconnecting various pipelines, wiring harnesses, and the like of the air compressor, thereby making it easy to perform maintenance, repair, and other work on other parts of the air compressor in the event of a malfunction.

It is noted that the embodiment illustrated in FIGS. 3-5 is only one example of a split design for the external heat insulation 2, and the external heat insulation 2 may include any other suitable split design. For example, the external heat insulation 2 may include a front portion, a cartridge portion, and a cover, wherein the front portion and the cover are similar to the front portion 21 and the cover 24 illustrated in FIGS. 3-5, and wherein the cartridge portion includes the top portion 22 and the bottom portion 23 illustrated in FIGS. 3-5 that are formed as one piece. For example, the external heat insulation 2 may include an L-shaped portion, an upper portion, and a cover, wherein the upper portion and the cover are similar to the upper portion 22 and the cover 24 shown in FIGS. 3-5, and the L-shaped portion includes the front portion 21 and the bottom portion 23 shown in FIGS. 3-5 that are formed as one piece. As a further example, the external heat insulation 2 may include a front portion, a first upper portion, a second upper portion, a bottom portion, and a cover, wherein the front portion, the bottom portion, and the cover are similar to the front portion 21, the bottom portion 23, and the cover 24 illustrated in FIGS. 3-5, wherein the first upper portion and the second upper portion are two separate portions and are formed as one piece to correspond to the upper portion 22 illustrated in FIGS. 3-5.

FIGS. 7-15 illustrate different embodiments of the detachable connection of the cover 24, respectively. The detachable connection of the cover 24 will be illustrated with the split design shown in FIGS. 3-5. It is then to be understood that the detachable connection of the cover 24 may be applied to any other suitable split design of the external heat insulation 2.

Reference is made to FIG. 7, which illustrates a first embodiment of the detachable connection of the cover 24.

In this embodiment, the cover 24 is detachably attached to the front side portion (e.g., front portion 21) and the upper side portion (e.g., upper portion 22) of the external heat insulation 2 by means of a band member 31.

Continued reference is made to FIG. 8, which illustrates a cross-sectional view of the portions in circles A and B in FIG. 7. The front portion 21 and the upper portion 22 are provided with band fixing holes 41 adjacent the first notch 213 and the second notch 223, respectively. the band fixing holes 41 may be threaded holes. The band fixing holes 41 of the front portion 21 and the upper portion 22 are preferably disposed in the same plane which is parallel to the direction of extension of the front portion to the rear portion of the volumetric air compressor body 1.

The band member 31 has retaining rings 311 at its ends. Each retaining ring 311 is arranged to be substantially aligned with a corresponding band fixing hole 41. Screw fasteners 51 are threaded through the aligned band fixing holes 41 and retaining rings 311, and are screwed into the band fixing holes 41, thereby fixing the band member 31 to the external heat insulation 2.

The length of the band member 31 may be designed to be substantially equal to the shortest distance passing from the band fixing hole 41 of the front portion 21 along the outer surface of the cover 24 to the band fixing hole 41 of the upper portion 22, or the length of the band member 31 may be designed to be slightly less than the the shortest distance in the event that the band member 31 is a resilient member. As a result, when the band member 31 is secured to the external heat insulation 2 by means of the fasteners 51, the band member 31 will press against the cover 24 towards the interior of the external heat insulation 2, thereby firmly connecting the cover 24 to the front portion 21 and the upper portion 22.

In the event that the cover 24 needs to be removed, one of the fasteners 51 can be loosened and disengaged from the band fixing hole 41, thereby releasing a corresponding end of the band member 31 to permit removal of the cover 24.

Reference is made to FIGS. 9 to 11, which illustrate a second embodiment of the detachable connection of the cover 24. The upper side of FIG. 9 illustrates a first state of the external heat insulation 2 in the second embodiment, and the bottom side illustrates a second state of the external heat insulation 2 in the second embodiment.

Referring to FIG. 10, in a second embodiment, an upper side portion (e.g., the upper portion 22) of the external heat insulation 2 is provided with a first fixing hole 42 (e.g., refer to A in FIG. 10) adjacent to the second notch 223. The cover 24 has an extension portion 241. The extension portion 241 covers at least the portion of the upper portion 22 provided with the first fixing hole 42 when the cover 24 is connected to the upper portion 22. The cover 24 is provided with a second fixing hole 242 at the extension portion 241 that is aligned with the first fixing hole 42 of the upper portion 22. One or both of the first fixing hole 42 and the second fixing hole 242 may be a threaded hole.

Alternatively, it will be appreciated by those skilled in the art that the upper side portion (e.g., upper portion 22) of the external heat insulation 2 may not be provided with the first fixing hole 42, while the front side portion (e.g., the front portion 21) of the external heat insulation 2 may be provided with the band fixing hole adjacent to the first notch 213, and that the extension portion 241 of the cover 24 may cover at least the portion of the front portion 21 that is provided with the band fixing hole and is provided with a cover fixing hole that is aligned with the band fixing hole of the front portion 21.

Referring to A and C in FIG. 11, an upper side portion (e.g., the upper portion 22) of the external heat insulation 2 is provided with a first protruding portion 225 adjacent to the first fixing hole 42 and offset toward the rear from the first fixing hole 42, and a front side portion (e.g., the front portion 21) of the external heat insulation 2 is provided with a second protruding portion 215 adjacent to the first notch 213. The first protruding portion 225 may be in the form of a shape that bends toward the rear, and the second protruding portion 215 may have a shape that is bent toward the bottom.

In a first state of the second embodiment of the external heat insulation 2 as shown on the top in FIG. 9, the cover 24 is detachably connected to the upper portion 22 by means of fasteners 52, such as screws, wherein the fasteners 52 are screwed to the aligned first fixing hole 42 and the second fixing hole 242, thereby connecting the upper portion 22 and the cover 24 together (refer to A in FIG. 10). When it is necessary to remove the cover 24 in the first state, the fasteners 52 can be loosen and disengaged from the first fixing hole 42 and the second fixing hole 242, thereby releasing the cover 24 from the upper portion 22.

In the second state of the external heat insulation 2 of the second embodiment as shown on the bottom in FIG. 9, a band member 32 may be provided. The band member 32 may be similar to the band member 31 of the first embodiment. The band member 32 likewise has retaining rings at both ends. The band member 32 is resilient and the length of the band member 32 is slightly less than the shortest distance passing from the first protruding portion 225 of the upper portion 22 along the outer surface of the cover 24 to the second protruding portion 215 of the front portion 21. Unlike the first embodiment, the band member 32 is attached to (e.g., hooked onto) the first protruding portion 225 of the upper portion 22 and the second protruding portion 215 of the front portion 21 by means of the retaining rings, respectively. As a result, the band member 32 will be pressed against the cover 24 towards the interior of the external heat insulation 2, thereby securely connecting the cover 24 to both the front portion 21 and the upper portion 22. In the event that it is necessary to remove the cover 24 in a second state, the band member 32 may be stretched to disengage one of the retaining rings from the corresponding protruding portion, thereby releasing the cover 24 from the front portion 21 and the upper portion 22.

The detachable connection of the cover 24 of the second embodiment allows the cover 24 to be detachably connected to the upper portion 22 firstly in a first state and to be detachably connected to the front portion 21 and the upper portion 22 in a second state by means of the band member 32 without the aid of the fastener 52.

The fastening screws are susceptible to damage or loss after multiple disassemblies during exchange of the oil removal cartridge or other repair or maintenance operations of the external heat insulation 2. The detachable connection of the cover 24 of the second embodiment makes it possible to easily connect the cover 24 to the front portion 21 and the upper portion 22 of the external heat insulation 2 with the help of the band member 32 only and without the need for other special tools, after the fastening screws have been damaged or lost.

Reference is made to FIGS. 12 through 13, which illustrate a third embodiment of the detachable connection of the cover 24.

In this embodiment, the cover 24 is connected to the external heat insulation 2 by a snap connection.

As shown in A and B of FIG. 13, the cover 24 is provided with resilient snap fastener members 246 adjacent to the first notch 213 in the front side portion (e.g., the front portion 21) and the second notch 223 in the upper side portion (e.g., the upper portion 22), respectively. The front portion 21 and the upper portion 22 are provided with slots 216 and 226 corresponding to the snap fastener members 246 at the first notch 213 and the second notch 223, respectively.

Upon connecting the cover 24 to the external heat insulation 2, the resilient snap fastener member 246 of the cover 24 may be inserted into and engage the slots 216 and 226 of the front portion 21 and the upper portion 22, thereby forming a snap connection that connects the cover 24 to the external heat insulation 2. The resilient snap member 246 provides an elastic force to prevent the snap member 246 from disengaging from the corresponding slot.

When it is necessary to remove the cover 24, a force resisting the elastic force is applied to disengage the snap members 246 from the slots 216 and 226, thereby permitting release of the cover 24 from the front portion 21 and the upper portion 22.

Reference is made to FIGS. 14 to 15, which illustrate a variation of the third embodiment of the detachable connection of the cover 24.

In a variant embodiment, the cover 24 is also connected to the external heat insulation 2 by means of a snap connection.

Unlike the third embodiment, in the variant embodiment, the upper portion 22 is provided with two oppositely resilient snap fasteners 227 adjacent to the second notch 223, at positions corresponding to the sides of the cover 24. The cover 24 is provided with two slots 247 corresponding to the snap fasteners 227.

Upon connecting the cover 24 to the external heat insulation 2, the two resilient snap fastener members 227 of the upper portion 22 may be inserted into and engage each of the two slots 247 of the cover 24, thereby forming a snap connection that connects the cover 24 to the external heat insulation 2. The resilient snap fastener members 227 provide an elastic force to prevent the snap fastener members 227 from disengaging from the corresponding slots.

When it is necessary to remove the cover 24, a force resisting the elastic force is applied to disengage the snap member 227 of the upper portion 22 from the slot 247 of the cover 24, thereby permitting the release of the cover 24 from the front portion 21.

Alternatively, it will be appreciated by those skilled in the art that the upper portion 22 may not be provided with snap fasteners 227, and the front portion 21 may be provided with two resilient snap fasteners adjacent to the first notch 213 at locations corresponding to the sides of the cover 24.

Although the present disclosure has been described above with reference to the embodiments, various improvements can be made, and parts thereof can be replaced with equivalents without departing from the scope of the present disclosure. In particular, as long as there is no structural conflict, the features in the embodiments disclosed herein may be used in combination with each other in any manner, and the cases of such combinations are not exhaustively described in this specification merely for the sake of saving space and resources. Therefore, the present disclosure is not limited to the particular embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.