BINDING MACHINE

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC § 119 from Japanese Patent Application No. 2024-073421 filed on Apr. 30, 2024, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a binding machine for binding a to-be-bound object such as a reinforcing bar with a wire.

BACKGROUND ART

For concrete buildings, reinforcing bars are used so as to improve strength. The reinforcing bars are bound with wires so that the reinforcing bars do not deviate from predetermined positions during concrete placement.

In the related art, suggested is a binding machine referred to as a reinforcing bar binding machine configured to wind a wire on two or more reinforcing bars and to twist the wire wound on the reinforcing bars, thereby binding the two or more reinforcing bars with the wire.

The binding machine guides the wire fed by a drive force of a motor and curled to a binding portion, which twists the wire by a guide called a curl guide or the like, and twists the wire wound around the reinforcing bars by the binding portion, thereby binding the reinforcing bars with the wire. In order to guide the curled wire to the binding portion, a binding machine is suggested which has a guiding facilitation part that comes into contact with a wire from a radially outer side of a loop formed by the curled wire and applies, to the wire, a force that changes a feeding path of the wire (for example, see Patent Literature 1).

In addition, when a diameter of the reinforcing bars to be bound with the wire increases, it is necessary to increase a diameter of the feeding path of the wire that is wound in an annular shape around the reinforcing bars. Therefore, a reinforcing bar binding machine is suggested which can reliably guide the wire to the binding portion even when the diameter of the feeding path of the wire, which becomes an annular shape, increases (for example, see Patent Literature 2).

Patent Literature: JP2022-164438A

Patent Literature: JP7302302B

In the binding machine of the related art in which the diameter of the reinforcing bars to be bound with the wire is small and the diameter of the feeding path of the wire, which is wound in an annular shape, is also small, the wire guided to the curl guide passes through a path spaced from a bottom surface portion of the curl guide. In contrast, when the diameter of the feeding path of the wire, which is wound in an annular shape, increases, a tip of the wire guided to the curl guide comes into contact with the bottom surface portion of the curl guide. For this reason, the resistance caused by friction when the wire slides along the bottom surface portion increases, potentially making it impossible to feed the wire to the binding portion.

An object of the present disclosure is to provide a binding machine configured to be able to reliably guide a wire whose tip is in contact with a bottom surface portion of a curl guide.

SUMMARY OF INVENTION

An aspect of the present disclosure is a binding machine including: a wire feeding portion configured to feed a wire; a curl forming portion configured to form an annular feeding path for winding the wire fed by the wire feeding portion around a to-be-bound object; and a binding portion configured to twist the wire wound on the to-be-bound object. The curl forming portion includes an arm part configured to curl the wire fed by the wire feeding portion, and a curl guide part configured to guide the wire curled by the arm part to the binding portion. The curl guide part includes a bottom surface portion on a radially outer side of the annular feeding path. The bottom surface portion includes a guiding portion forming at least a part of a tip portion side of the curl guide part and configured to guide a tip of the wire toward a base end portion side of the curl guide part.

In addition, another aspect of the present disclosure is a binding machine including: a wire feeding portion configured to feed a wire; a curl forming portion configured to form an annular feeding path for winding the wire fed by the wire feeding portion around a to-be-bound object; and a binding portion configured to twist the wire wound on the to-be-bound object. The curl forming portion includes an arm part configured to curl the wire fed by the wire feeding portion, and a curl guide part configured to guide the wire curled by the arm part to the binding portion. The curl guide part includes a bottom surface portion on a radially outer side of the annular feeding path, the bottom surface portion includes a guiding portion forming at least a part of a tip portion side of the curl guide part, the guiding portion has an inclined surface inclined with respect to the bottom surface portion in a direction in which a first end portion on the tip portion side of the curl guide part becomes closer to the arm part than a second end portion on a base end portion side of the curl guide part. The inclined surface is configured such that a dimension of the first end portion with respect to the second end portion is longer in a direction parallel to a virtual extension line of the bottom surface portion than in a direction orthogonal to the virtual extension line of the bottom surface portion.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is an internal configuration view showing an example of a reinforcing bar binding machine of the present embodiment, as viewed from a side.

FIG. 1B is a side view of main parts showing the example of the reinforcing bar binding machine of the present embodiment.

FIG. 2 is an appearance side view showing the example of the reinforcing bar binding machine of the present embodiment.

FIG. 3A is an appearance perspective view showing the example of the reinforcing bar binding machine of the present embodiment.

FIG. 3B is an appearance perspective view showing the example of the reinforcing bar binding machine of the present embodiment.

FIG. 4A is a side view of main parts showing an example of an operation of the reinforcing bar binding machine of the present embodiment.

FIG. 4B is a side view of main parts showing an example of the operation of the reinforcing bar binding machine of the present embodiment.

FIG. 4C is a side view of main parts showing an example of the operation of the reinforcing bar binding machine of the present embodiment.

FIG. 4D is a side view of main parts showing an example of the operation of the reinforcing bar binding machine of the present embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an example of a reinforcing bar binding machine as an embodiment of the binding machine of the present disclosure will be described with reference to the drawings.

Configuration Example of Reinforcing Bar Binding Machine of Present Embodiment

FIG. 1A is an internal configuration view showing an example of a reinforcing bar binding machine of the present embodiment, as viewed from a side, FIG. 1B is a side view of main parts showing the example of the reinforcing bar binding machine of the present embodiment, and FIG. 2 is an appearance side view showing the example of the reinforcing bar binding machine of the present embodiment. In addition, FIGS. 3A and 3B are appearance perspective views showing the example of the reinforcing bar binding machine of the present embodiment.

A reinforcing bar binding machine 1A has such a shape that an operator grips with a hand, and includes a main body part 10 and a handle part 11. In addition, the reinforcing bar binding machine 1A feeds wires W in a forward direction indicated by an arrow F, winds the wires around reinforcing bars S, which are a to-be-bound object, feeds the wires W wound around the reinforcing bars S in a reverse direction indicated by an arrow R, winds the wires on the reinforcing bars S, and twists the wires W, thereby binding the reinforcing bars S with the wires W. The reinforcing bar binding machine 1A binds the reinforcing bars S with a plurality of wires W, in this example, two wires W.

In order to implement the above-described functions, the reinforcing bar binding machine 1A includes a magazine 2 in which the wires W are accommodated, a wire feeding portion 3 that feeds the wires W, and a wire guide portion 4 that guides the wires W, which are fed by the wire feeding portion 3. In addition, the reinforcing bar binding machine 1A includes a curl forming portion 5 that forms an annular feeding path for winding the wires W, which are fed by the wire feeding portion 3, around the reinforcing bars S, and a cutting portion 6 that cuts the wires W wound on the reinforcing bars S. In addition, the reinforcing bar binding machine 1A includes a binding portion 7 that twists the wires W wound on the reinforcing bars S, and a drive portion 8A that drives the binding portion 7. In addition, the reinforcing bar binding machine 1A includes a tip guide part 9 (9L, 9R) against which the reinforcing bars S are butted and which supports the curl forming portion 5.

The magazine 2 is an example of an accommodation portion, and a reel 20 on which the long wires W are wound to be reeled out is rotatably and detachably accommodated therein. For the wire W, a wire made of a plastically deformable metal wire, a wire having a metal wire covered with a resin, or a twisted wire is used. In a configuration in which the reinforcing bars S are bound with two wires W, the two wires W are wound on the reel 20 and can be pulled out at the same time from the reel 20.

The wire feeding portion 3 includes a pair of feeding gears 30 that sandwiches and feeds the wires W. In the wire feeding portion 3, a rotating operation of a feeding motor (not shown) is transmitted to the feeding gears 30, causing the feeding gears 30 to rotate. Additionally, in the wire feeding portion 3, a rotation direction of the feeding motor (not shown) is switched between forward and reverse directions to switch a rotation direction of the feeding gears 30, thereby switching a feeding direction of the wires W between the forward and reverse directions. In the configuration where the reinforcing bars S is bound with two wires W, the wire feeding portion 3 aligns the two wires W in a radial direction of the wires W and feeds the wires.

The wire guide portion 4 is arranged on upstream and downstream sides of the feeding gears 30 with respect to the feeding direction of the wires W that are fed in the forward direction. In the configuration where the reinforcing bars S are bound with two wires W, the wire guide portion 4 aligns the two entering wires W in parallel along a direction in which the pair of feeding gears 30 is aligned and guides the same between the pair of feeding gears 30.

The curl forming portion 5 includes an arm part 50 that curls the wires W, which are fed by the wire feeding portion 3, and a curl guide part 51 that guides the wires W curled by the arm part 50 to the binding portion 7. The curl forming portion 5 curls the wires W, which are fed by the wire feeding portion 3 and pass through the arm part 50, by the arm part 50 and guides the wires W curled by the arm part 50 to the binding portion 7 by the curl guide part 51. Thereby, the curl forming portion 5 forms a feeding path of the wires W, represented by a two-dot chain line, passing through the curl guide part 51 from the arm part 50 and reaching the binding portion 7. The feeding path of the wires W passing through the curl guide part 51 from the arm part 50 and reaching the binding portion 7 is called an annular feeding path Ru.

The arm part 50 has a groove portion 50a, which has a width through which the wires W pass and is formed along a circumferential direction of the annular feeding path Ru. In the configuration where the reinforcing bars S are bound with two wires W, the arm part 50 aligns the two entering wires W in parallel in a direction in which the wires are aligned along an axial direction of the annular feeding path Ru.

The curl guide part 51 has a width-expanding portion 52, into which the wires W curled by the arm part 50 enter, and a return guide portion 53, which guides the wires W entering the width-expanding portion 52 to the binding portion 7.

The width-expanding portion 52 has a bottom surface portion 52a provided on a radially outer side of the annular feeding path Ru, and side surface portions 52b provided on both sides in the axial direction of the annular feeding path Ru.

The bottom surface portion 52a has a guiding portion 52c, which constitutes at least a part of a tip portion 51a side of the curl guide part 51.

The guiding portion 52c has an inclined surface 52d provided on a trajectory, along which the tips of the wires W entering the width-expanding portion 52 pass, on the radially outer side of the annular feeding path Ru. The inclined surface 52d of the guiding portion 52c is configured as a flat surface in the present example. In the guiding portion 52c, the inclined surface 52d extends from a tip portion 51a side of the curl guide part 51 toward a base end portion 51b side of the curl guide part 51, which is an end portion on the binding portion 7 side, by a length, within which the tips of the wires W entering the width-expanding portion 52 are assumed to come into contact with the inclined surface, and connects to the bottom surface portion 52a.

In the guiding portion 52c, the inclined surface 52d is inclined with respect to the bottom surface portion 52a in a direction in which a first end portion 52c1, which is an end portion on the tip portion 51a side of the curl guide part 51, becomes closer to the arm part 50 than a second end portion 52c2, which is an end portion on the bottom surface portion 52a side.

The inclined surface 52d is configured such that a dimension of the first end portion 52c1 relative to the second end portion 52c2 is longer in a direction parallel to a virtual extension line of the bottom surface portion 52a than in a direction orthogonal to the virtual extension line of the bottom surface portion 52a. That is, the guiding portion 52c is configured such that a length L of the inclined surface 52d from the first end portion 52c1 to the second end portion 52c2 along a direction parallel to a plane of the bottom surface portion 52a is greater than a height H of the first end portion 52c1 of the inclined surface 52d relative to the bottom surface portion 52a along a direction intersecting the plane of the bottom surface portion 52a.

Thereby, in the guiding portion 52c, the inclined surface 52d extends along the circumferential direction of the annular feeding path Ru on the tip portion 51a side of the curl guide part 51 with respect to the bottom surface portion 52a. In the guiding portion 52c, a cross-sectional shape of the inclined surface 52d in a direction parallel to the annular feeding path Ru, that is, a cross-sectional shape of the inclined surface 52d when the curl guide part 51 is viewed from a side along the axial direction of the annular feeding path Ru extends, in the present example, in a straight line shape in a predetermined direction along the circumferential direction of the annular feeding path Ru.

In addition, the bottom surface portion 52a extends along the circumferential direction of the annular feeding path Ru on the base end portion 51b side of the curl guide portion 51 with respect to the guide portion 52c. The bottom surface portion 52a, when the curl guide part 51 is viewed from a side along the axial direction of the annular feeding path Ru, has a cross-sectional shape extending in a straight line in a predetermined direction along the circumferential direction of the annular feeding path Ru, in the present example, in a tangential direction of a vertex of a portion of the annular feeding path Ru facing the bottom surface portion 52a.

The side surface portions 52b and 52b include first side surface portions 52b1 (52b1L, 52b1R), which are composed of surfaces with parallel spacing, and second side surface portions 52b2 (52b2L, 52b2R), which are composed of surfaces with spacing that narrows from the tip portion 51a side toward the base end portion 51b side of the curl guide part 51.

The first side surface portions 52b1L and 52b1R extend from the tip portion 51a of the curl guide part 51 toward the base end portion 51b side of the curl guide part 51 by a predetermined length.

The first side surface portions 52b1L and 52b1R and the second side surface portions 52b2L and 52b2R protrude toward a radially inner side of the annular feeding path Ru with respect to the inclined surface 52d of the guiding portion 52c and the bottom surface portion 52a.

In the side surface portions 52b and 52b, the entirety of the first side surface portions 52b1L and 52b1R and parts of the second side surface portions 52b2L and 52b2R on sides connecting to the first side surface portions 52b1L and 52b1R are provided on both side portions of the inclined surface 52d. In addition, in the side surface portions 52b and 52b, the remainders of the second side surface portions 52b2L and 52b2R are provided on both side portions of the bottom surface portion 52a.

Thereby, the guiding portion 52c has a shape in which a width of the inclined surface 52d is the same at the portions where the first side surface portions 52b1L and 52b1R are provided on both sides. In addition, the guiding portion 52c has a shape in which a width of the inclined surface 52d gradually narrows from the tip portion 51a side toward the base end portion 51b side of the curl guide part 51 at the portions where the second side surface portions 52b2L and 52b2R are provided on both sides. The bottom surface portion 52a has a shape in which a width gradually narrows from the tip portion 51a side toward the base end portion 51b side of the curl guide part 51.

In the side surface portions 52b and 52b, the first side surface portion 52b 1L and the second side surface portion 52b2L and the inclined surface 52d of the guiding portion 52c are in contact with each other, respectively so as to prevent the wire W from entering between the first side surface portion 52b 1L and the second side surface portion 52b2L and the inclined surface 52d of the guiding portion 52c. Note that a gap narrower than a diameter of the wire W may be formed between the first side surface portion 52b 1L and the second side surface portion 52b2L and the inclined surface 52d of the guiding portion 52c.

Additionally, in the side surface portions 52b and 52b, the first side surface portion 52b1R and the second side surface portion 52b2R and the inclined surface 52d of the guiding portion 52c are in contact with each other, respectively, so as to prevent the wire W from entering between the first side surface portion 52b1R and the second side surface portion 52b2R and the inclined surface 52d of the guiding portion 52c. Note that a gap narrower than the diameter of the wire W may be formed between the first side surface portion 52b1R and the second side surface portion 52b2R and the inclined surface 52d of the guiding portion 52c.

In the side surface portions 52b and 52b, the second side surface portion 52b2L and the bottom surface portion 52a are in contact with each other so as to prevent the wire W from entering between the second side surface portion 52b2L and the bottom surface portion 52a. Note that a gap narrower than the diameter of the wire W may be formed between the second side surface portion 52b2L and the bottom surface portion 52a.

Additionally, in the side surface portions 52b and 52b, the second side surface portion 52b2R and the bottom surface portion 52a are in contact with each other so as to prevent the wire W from entering between the second side surface portion 52b2R and the bottom surface portion 52a. Note that a gap narrower than the diameter of the wire W may be formed between the second side surface portion 52b2R and the bottom surface portion 52a.

The return guide portion 53 has an inclined portion 53a provided on the radially outer side of the annular feeding path Ru, and side surface portions 53b (53bL, 53bR) provided on both sides in the axial direction of the annular feeding path Ru.

The inclined portion 53a is configured as a surface inclined with respect to the bottom surface portion 52a in the direction toward the binding portion 7 along the circumferential direction of the annular feeding path Ru. The inclined portion 53a extends along the circumferential direction of the annular feeding path Ru on the base end portion 51b side of the curl guide part 51 with respect to the bottom surface portion 52a. The inclined portion 53a, when the curl guide part 51 is viewed from a side along the axial direction of the annular feeding path Ru, extends in a straight line in a predetermined direction along the circumferential direction of the annular feeding path Ru, in the present example, in a tangential direction of the annular feeding path Ru.

The side surface portions 53bL and 53bR are composed of surfaces with parallel spacing along the direction in which the inclined portion 53a extends. The side surface portions 53bL and 53bR protrude toward the radially inner side of the annular feeding path Ru with respect to the inclined portion 53a. In the configuration where the reinforcing bars S are bound with two wires W, the return guide portion 53 has the side surface portions 53bL and 53bR facing each other at a distance of about twice the diameter of the wire W, and aligns the two entering wires W in parallel in the direction in which the wires are aligned along the axial direction of the annular feeding path Ru.

In the curl guide part 51, the bottom surface portion 52a, first side surface portions 52b1L and 52b1R, and second side surface portions 52b2L and 52b2R of the width-expanding portion 52, and the side surface portions 53bL and 53bR of the return guide portion 53 are formed integrally by press processing of sheet metal such as iron. Additionally, in the curl guide part 51, the guiding portion 52c manufactured in a predetermined shape using a plate material such as iron is fixed to the bottom surface portion 52a by welding or the like. Additionally, in the curl guide part 51, a plate material, such as iron, formed with the inclined portion 53a is fixed between the side surface portions 53bL and 53bR by a fastening member. Note that in the curl guide part 51, the guiding portion 52c may be configured integrally with the bottom surface portion 52a by press processing or the like.

The cutting portion 6 includes a fixed blade part 60, a movable blade part 61 that cuts the wires W in cooperation with the fixed blade part 60, and a transmission mechanism 62 that transmits an operation of the binding portion 7 to the movable blade part 61. The cutting portion 6 cuts the wires W by a rotating operation of the movable blade part 61 about the fixed blade part 60 as a fulcrum shaft.

The binding portion 7 includes a wire locking body 70 to which the wires W are locked, and a sleeve 71 for actuating the wire locking body 70. The drive portion 8 includes a twist motor 80 and a decelerator 81 that performs deceleration and torque amplification.

In the reinforcing bar binding machine 1A, the handle part 11 extends downward from the main body part 10. In addition, a battery 15 is detachably mounted to a lower part of the handle part 11. In addition, in the reinforcing bar binding machine 1A, the magazine 2 is provided in front of the handle part 11.

In the reinforcing bar binding machine 1A, a trigger 12 is provided on a front side of the handle part 11, and a switch 13 is provided inside the handle part 11. In the reinforcing bar binding machine 1A, a control portion 100 controls the twist motor 80 and the feeding motor (not shown), in response to a state of the switch 13 that is pressed by an operation on the trigger 12.

The tip guide part 9L is provided at a front end portion of the main body part 10, on one side. The tip guide part 9L includes a butting portion 9La against which the reinforcing bars S are butted, an arm support portion 90L supported by the arm part 50, a curl guide support portion 91L supported by the curl guide part 51, and a main body support portion 92L supported by the main body part 10.

In the tip guide part 9L, the arm support portion 90L is fixed to the arm part 50 by screws 90s. Additionally, in the tip guide part 9L, the curl guide support portion 91L is fixed to the curl guide part 51 by a screw 91s. Additionally, in the tip guide part 9L, the main body support portion 92L is fixed to the main body part 10 by screws 92s.

The tip guide part 9R is provided at a front end portion of the main body part 10, on the other side. The tip guide part 9R includes a butting portion 9Ra against which the reinforcing bars S are butted, an arm support portion 90R supported by the arm part 50, a curl guide support portion 91R supported by the curl guide part 51, and a main body support portion 92R supported by the main body part 10.

In the tip guide part 9R, the arm support portion 90R is fixed to the arm part 50 by screws 90s. Additionally, in the tip guide part 9R, the curl guide support portion 91R is fixed to the curl guide part 51 by a screw 91s. Additionally, in the tip guide part 9R, the main body support portion 92R is fixed to the main body part 10 by screws 92s.

Example of Operational Effects of Reinforcing Bar Binding Machine of Present Embodiment

FIGS. 4A to 4D are side views of main parts showing an example of an operation of the reinforcing bar binding machine of the present embodiment. Below, an operation of binding the reinforcing bars S with the wires W by the reinforcing bar binding machine 1A of the present embodiment will be described with reference to each drawing. Note that in FIGS. 4A to 4D, the reinforcing bars as a to-be-bound object are not shown.

When the reinforcing bars S are inserted between the arm part 50 and the curl guide part 51 of the curl forming portion 5 and the trigger 12 is operated, the feeding motor (not shown) is driven in the forward rotation direction, and the wires W sandwiched by the pair of feeding gears 30 are fed in the forward direction indicated by the arrow F.

In the configuration where the reinforcing bars S are bound with two wires W, the two wires W are fed aligned in parallel along the axial direction of the annular feeding path Ru by the wire feeding portion 3 and the wire guide portion 4.

The wires W, which are fed in the forward direction, pass through the wire locking body 70 of the binding portion 7 and are fed to the arm part 50 of the curl forming portion 5. The wires W pass through the curl guide 50 and are thus curled to be wound around the reinforcing bars S along the annular feeding path Ru.

The wires W curled by the arm part 50 are guided to the curl guide part 51 by being further fed in the forward direction by the wire feeding portion 3 and enter the curl guide part 51 from the width-expanding portion 52. The curl guide part 51 is provided with the width-expanding portion 52 on the tip portion 51a side, so that the wires W curled by the arm part 50 enter between the first side surface portions 52b1L and 52b1R, and the tips of the wires W are directed toward the bottom surface portion 52a.

In a configuration where the bottom surface portion 52a is not provided with the guiding portion 52c, the tips of the wires W entering between the first side surface portions 52b1L and 52b1R come into contact with the bottom surface portion 52a. In the state in which the tips of the wires W are in contact with the bottom surface portion 52a of the curl guide part 51, the wires W are further fed in the forward direction by the wire feeding portion 3, so that a force to move the tips of the wires W from the tip portion 51a side toward the base end portion 51b side of the curl guide part 51 is applied to the wires W.

However, in the configuration where the bottom surface portion 52a is not provided with the guiding portion 52c, there is a possibility that the tips of the wires W, which are fed in the forward direction by the wire feeding portion 3, cannot move along the surface of the bottom surface portion 52a from the tip portion 51a side toward the base end portion 51b side of the curl guide part 51. If the tips of the wires W cannot move along the surface of bottom surface portion 52a, the wires W cannot be guided to the binding portion 7.

Whether the tip of the wire W can move along the surface of the bottom surface portion 52a in the state in which the tip of the wire W is in contact with the bottom surface portion 52a of the curl guide part 51 depends on an entering angle of the wire W with respect to the bottom surface portion 52a just before the tip of the wire W, upon entering the width-expanding portion 52, comes into contact with the bottom surface portion 52a.

Therefore, the reinforcing bar binding machine 1A includes the guiding portion 52c having the inclined surface 52d and provided on the bottom surface portion 52a on the tip portion 51a side of the curl guide part 51.

As shown in FIG. 4A, in the guiding portion 52c, the inclined surface 52d is inclined with respect to the bottom surface portion 52a such that an entering angle θ1 of the wire W with respect to the inclined surface 52d just before the tip of the wire W, upon entering the width-expanding portion 52, comes into contact with the inclined surface 52d becomes 50° or less. Note that the entering angle refers to an angle at the moment the wire W comes into contact with the inclined surface 52d, or just before such contact, and does not indicate an angle at the moment the wire W moves after coming into contact with the inclined surface 52d.

The wires W, which are fed in the forward direction by the wire feeding portion 3 and curled by the arm part 50 and enter the width-expanding portion 52, are stretched in a straight line shape over a predetermined length range on the tip side. The entering angle of the wire W with respect to the inclined surface 52d of the guiding portion 52c refers to an angle, when the curl guide part 51 is viewed from a side along the axial direction of the annular feeding path Ru, formed between a direction in which the tip side of the wire W, just before coming into contact with the inclined surface 52d, is stretched in a straight line shape and the inclined surface 52d.

Note that if the wire W is stretched in a curved shape over a predetermined length range from the tip, a tangent to the tip of the wire W or a vertex near the tip may be regarded as the direction in which the tip side of the wire W is stretched. In this case, an angle formed between a direction in which the tangent to the tip of the wire W, just before coming into contact with the inclined surface 52d, or the vertex near the tip extends and the inclined surface 52d may be regarded as the entering angle of the wire W with respect to the inclined surface 52d.

In addition, during an operation of cutting the wire W by the cutting portion 6, a portion on the tip side of the wire W may be deformed into a shape bent at an obtuse angle. In this case, an angle formed between a stretching direction of the deformed portion on the tip side of the wire W and the inclined surface 52d may be regarded as the entering angle of the wire W with respect to the inclined surface 52d.

When the wires W are further fed in the forward direction by the wire feeding portion 3 in the state in which the tips of the wires W are in contact with the inclined surface 52d of the guiding portion 52c, the tips of the wires W can move along the inclined surface 52d of the guiding portion 52c toward the base end portion 51b side of the curl guide part 51 if the entering angle θ1 of the wires W with respect to the inclined surface 52d is 50° or less. Thereby, the tips of the wires W, which are fed in the forward direction by the wire feeding portion 3, move to a position where they come into contact with the bottom surface portion 52a, as shown in FIG. 4B.

When the wires W entering the curl guide part 51 from the width-expanding portion 52 are located near the first side surface portion 52b1L, the tips of the wires W move along the inclined surface 52d of the guiding portion 52c toward the base end portion 51b side of the curl guide part 51, and the wire W comes into contact with the first side surface portion 52b 1L, so that the wires are guided between the side surface portions 53bL and 53bR of the return guide portion 53. In addition, when the wires W entering the curl guide part 51 from the width-expanding portion 52 are located near the first side surface portion 52b 1R, the tips of the wires W move along the inclined surface 52d of the guiding portion 52c toward the base end portion 51b side of the curl guide part 51, and the wire W comes into contact with the first side surface portion 52b1R, so that the wires are guided between the side surface portions 53bL and 53bR of the return guide portion 53.

The reinforcing bar binding machine 1A is configured so that an entering angle θ2 of the wire W with respect to the bottom surface portion 52a is also 50° or less. Accordingly, when the wires W are further fed in the forward direction by the wire feeding portion 3 in the state in which the tips of the wires W are in contact with the bottom surface portion 52a, the tips of the wires W can move along the surface of the bottom surface portion 52a toward the base end portion 51b side of the curl guide part 51. Thereby, the tips of the wires W, which are fed in the forward direction by the wire feeding portion 3, move to a position where they come into contact with the inclined portion 53a, as shown in FIG. 4C. In addition, when the wires W are fed to the position where the tips of the wires W come into contact with the inclined portion 53a, portions, in the circumferential direction, of the wires W come into contact with the bottom surface portion 52a and the inclined surface 52d of the guiding portion 52c.

The reinforcing bar binding machine 1A is configured so that an entering angle θ3 of the wire W with respect to the inclined portion 53a is also 50° or less. Accordingly, when the wires W are further fed in the forward direction by the wire feeding portion 3 in the state in which the tips of the wires W are in contact with the inclined portion 53a, the tips of the wires W can move along the surface of the inclined portion 53a toward the base end portion 51b side of the curl guide part 51. Thereby, the tips of the wires W, which are fed in the forward direction by the wire feeding portion 3, are guided to the binding portion 7, as shown in FIG. 4D. In addition, when the wires W are fed to a position where the tips of the wires W are guided to the binding portion 7, portions, in the circumferential direction, of the wires W come into contact with the bottom surface portion 52a.

When the wires W are further fed in the forward direction by the wire feeding portion 3, the wires W pass through the wire locking body 70 and are fed to a position where the tips of the wires W are butted against a feeding regulation portion 18, at which point the driving of the feeding motor (not shown) is stopped.

After the feeding of the wires W in the forward direction is stopped, the twist motor 80 is driven in the forward rotation direction. The sleeve 71 is regulated from rotation in an operation area where the wires W are locked by the wire locking body 70. Thereby, the rotation of the twist motor 80 is converted into linear motion, causing the sleeve 71 to move in a direction of arrow A1, which is a forward direction. When the sleeve 71 moves in the forward direction, the wires W are locked by a predetermined operation of the wire locking body 70.

After advancing the sleeve 71 to the position where the wires W are locked by the wire locking body 70, the rotation of the twist motor 80 is temporarily stopped and the feeding motor is driven in the reverse rotation direction.

Thereby, the pair of feeding gears 30 is reversely rotated and the wires W sandwiched between the pair of feeding gears 30 are fed in the reverse direction denoted with the arrow R. The operation of feeding the wires W in the reverse direction winds the wires W on the reinforcing bars S.

After winding the wires W on the reinforcing bars S and stopping the driving of the feeding motor in the reverse rotation direction, the twist motor 80 is driven in the forward rotation direction, so that the sleeve 71 moves further in the forward direction indicated by arrow A1. The operation of the sleeve 71 moving in the forward direction is transmitted to the cutting portion 6 by the transmission mechanism 62, so that the movable blade part 61 rotates, and the wires W are cut at a predetermined position by an operation of the fixed blade part 60 and the movable blade part 61.

By driving the twist motor 80 in the forward rotation direction, the sleeve 71 is moved in the forward direction indicated by arrow A1 to cut the two wires W, and almost simultaneously, the wires W are pushed in the forward direction by the wire locking body 70, and tip sides and terminal end sides of the wires W are bent toward the reinforcing bars S.

After bending the tip sides and terminal end sides of the wires W toward the reinforcing bars S, the twist motor 80 is driven further in the forward rotation direction, so that the sleeve 71 moves further in the forward direction. When the sleeve 71 moves to a predetermined position, the regulation on the rotation of the sleeve 71 is released.

Thereby, the twist motor 80 is driven further in the forward rotation direction, so that the sleeve 71 rotates and an operation of twisting the wires W locked by the wire locking body 70 is started. When it is detected that the load on the twist motor 80 reaches its maximum as the wires W are twisted, the forward rotation of the twist motor 80 is stopped. Subsequently, when the twist motor 80 is driven in the reverse rotation direction, the sleeve 71 moves in a direction of arrow A2, which is a rearward direction, with its rotation regulated.

When the sleeve 71 moves in the rearward direction, the locking of the wires W by the wire locking body 70 is released, and the wires W, which have bound the reinforcing bars S, are disengaged from the wire locking body 70.

In a configuration of the curl forming portion 5 in which a radial length of the annular feeding path Ru is about 60 mm, the wires W curled by the arm part 50 and guided to the curl guide part 51 pass through a path spaced apart from the bottom surface portion 52a in the curl guide part 51.

In contrast, in a configuration of the curl forming portion 5 in which the radial length of the annular feeding path Ru is about 100 mm or longer, the wires W curled by the arm part 50 and guided to the curl guide part 51 pass through a path in which the tips come into contact with the bottom surface portion 52a.

Therefore, the reinforcing bar binding machine 1A includes the guiding portion 52c provided on the bottom surface portion 52a on the tip portion 51a side of the curl guide part 51. Thereby, the wires W curled by the arm part 50 and guided to the curl guide part 51 come into contact with the inclined surface 52d of the guiding portion 52c at the tips thereof.

When the wires W are further fed in the forward direction by the wire feeding portion 3 in the state in which the tips of the wires W are in contact with the inclined surface 52d, the tips of the wires W can move along the inclined surface 52d of the guiding portion 52c toward the base end portion 51b side of the curl guide part 51. Thereby, the tips of the wires W, which are fed in the forward direction by the wire feeding portion 3, can be moved to a position where they come into contact with the bottom surface portion 52a, and the wires W are further fed in the forward direction, so that the wires W can be guided to the binding portion 7 and a binding operation can be performed.

Note that an angle of the inclined surface 52d of the guiding portion 52c with respect to the bottom surface portion 52a is preferably 50° or less. In addition, a cross-sectional shape of the bottom surface portion 52a, when the curl guide part 51 is viewed from a side along the axial direction of the annular feeding path Ru, may be a multi-step shape having at least one step, or may be an arc shape. When the cross-sectional shape of the bottom surface portion 52a is an arc shape, the angle of the inclined surface 52d with respect to the bottom surface portion 52a may be defined based on a tangent to a vertex of the arc shape.

As described above, an aspect of the present disclosure is a binding machine including: a wire feeding portion configured to feed a wire; a curl forming portion configured to form an annular feeding path for winding the wire fed by the wire feeding portion around a to-be-bound object; and a binding portion configured to twist the wire wound on the to-be-bound object. The curl forming portion includes an arm part configured to curl the wire fed by the wire feeding portion, and a curl guide part configured to guide the wire curled by the arm part to the binding portion. The curl guide part includes a bottom surface portion on a radially outer side of the annular feeding path. The bottom surface portion includes a guiding portion forming at least a part of a tip portion side of the curl guide part and configured to guide a tip of the wire toward a base end portion side of the curl guide part.

In addition, another aspect of the present disclosure is a binding machine including: a wire feeding portion configured to feed a wire; a curl forming portion configured to form an annular feeding path for winding the wire fed by the wire feeding portion around a to-be-bound object; and a binding portion configured to twist the wire wound on the to-be-bound object. The curl forming portion includes an arm part configured to curl the wire fed by the wire feeding portion, and a curl guide part configured to guide the wire curled by the arm part to the binding portion. The curl guide part includes a bottom surface portion on a radially outer side of the annular feeding path, the bottom surface portion includes a guiding portion forming at least a part of a tip portion side of the curl guide part, the guiding portion has an inclined surface inclined with respect to the bottom surface portion in a direction in which a first end portion on the tip portion side of the curl guide part becomes closer to the arm part than a second end portion on a base end portion side of the curl guide part. The inclined surface is configured such that a dimension of the first end portion with respect to the second end portion is longer in a direction parallel to a virtual extension line of the bottom surface portion than in a direction orthogonal to the virtual extension line of the bottom surface portion.

In the present disclosure, when the wire is fed by the wire feeding portion in a state in which the tip of the wire is in contact with the guiding portion, the tip of the wire can move along the surface of the guiding portion toward the base end portion side of the curl guide part. This makes it possible to guide the wire to the binding portion and to perform a binding operation.

According to the present disclosure, it is possible to provide a binding machine configured to be able to reliably guide a wire whose tip is in contact with a bottom surface portion of a curl guide.