JPH072201U - Twisting hook actuation mechanism of the binding machine - Google Patents

Abstract

(57) [Abstract] [Purpose] Bundling capable of reliably grasping a part of the wire ring formed around the material to be bound even when the torsion hook is in the standby position in a state of deviating from the initial angle position. A twist hook operating mechanism of a machine is provided. [Structure] A torsion hook actuating mechanism has a control device for controlling starting and stopping of a hook drive motor. The control device starts and controls the hook drive motor so that the hook drive shaft is normally rotated with a torque smaller than the static friction of the sleeve. When the hook drive motor is started to rotate in the normal direction, the twist hook operating mechanism causes the sleeve to rotate normally along with the hook drive shaft, and the protrusion formed on the sleeve engages the normal rotation stopper to form the twist hook and the twist hook to move the wire loop. The part is positioned at the initial angular position where it can be grasped with certainty, and then, while the hook drive shaft further rotates in the forward direction, the sleeve is advanced by the engagement of the protrusion and the forward rotation stopper, and the wire ring is moved at the initial angle position. Close the twisting hook in the direction to grasp.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention binds a material to be bound by grasping a part of a wire ring formed by annularly winding around a material to be bound (for example, a plurality of reinforcing bars) with a twist hook and twisting the wire multiple times. The present invention relates to an operation mechanism of a torsion hook of a binding machine.

[0002]

[Prior art and its problems]

 As a twisting hook actuating mechanism of the above-mentioned type binding machine, one disclosed in Japanese Patent Publication No. 3-60989 is known. According to this torsion hook actuating mechanism, a chuck that slides in the axial direction is arranged on the outer periphery of the torsion hook support shaft that pivotally supports the torsion hook, and the movement of the chuck in the axial direction with respect to the torsion hook support shaft by the cam is performed. Open and close the twist hook.

According to the binding machine described in Japanese Patent Publication No. 3-60989, it is necessary to stop the torsion hook at a predetermined angular position after the binding work consisting of a series of steps is completed. For this reason, the torsion hook support shaft is rotated in the reverse direction after the binding work is completed and the torsion hook is opened, and at the same time, the torsion hook support member is brought into contact with the torsion hook support member, and the torsion hook support shaft is rotated to reverse the torsion hook support shaft. Prevent rotation. As a result, the torsion hook is stopped at the predetermined angle position. Since the twist hook abutting member is arranged at a position close to the bound member in the binding machine, the twist hook abutting member may hit the bound material during the binding work and may be damaged.

[0004]

[Problems to be solved by the device]

 In order to eliminate the drawbacks of the binding machine described in Japanese Examined Patent Publication No. 3-60989, the applicant of the present application filed a twist hook operating mechanism for the binding machine according to Japanese Patent Application No. 4-40687. This twist hook actuating mechanism continuously feeds the binding wire to an arc-shaped guide arranged in front of the wire feeding mechanism, and the wire fed from the tip of the arc-shaped guide is wound around the material to be bound multiple times. In the binding machine that binds the material to be bound, the hook drive motor is driven by turning the wire loop to form a wire ring, and grasping and twisting a part of this wire ring with the twist hook that is rotated forward and reverse by the hook drive motor. The hook drive shaft, which is connected to the shaft via a speed reducer, and the torsion hook support shaft, which is arranged in front of the hook drive shaft, are coaxially and relatively rotatably connected to each other, and a spiral groove is formed on the outer peripheral surface of the hook drive shaft. Then, a torsion hook with a long hole is pivotally supported on the hook support shaft so as to be openable and closable, and a sleeve is arranged on the outer peripheral surface of the hook drive shaft and the torsion hook support shaft. hand It is rotatable in a fixed range and axially movable, is fixed in the rotational direction with respect to the torsion hook support shaft, and is axially movable in a fixed range. A spherical ball storage part that partially engages the spiral groove is formed, and a pin that loosely fits into the long hole of the torsion hook is fixed near the tip of the sleeve. A plurality of protrusions are formed on the sleeve, and a forward rotation stopper and a reverse rotation stopper that engage with these protrusions to prevent forward and reverse rotation of the sleeve are arranged in the binding machine body near the outer peripheral surface of the sleeve.

When the hook drive shaft rotates in the normal direction, the protrusion engages with the normal rotation stopper to prevent the sleeve from rotating in the forward direction, and moves the sleeve axially forward together with the ball, whereby the twist hook is closed in the closing direction. When the sleeve rotates, the projection is removed from the forward rotation stopper at the front end of the axial movement range of the sleeve, and the sleeve and the hook drive shaft are integrally rotated in the forward direction. When the hook drive shaft reverses, the protrusion and the reverse stopper engage to move the sleeve axially to the standby position.

In the normal state, just before the twisting operation, the above-mentioned twist hook is positioned at a right angle and open with respect to a part of the wire ring around the material to be bound. At the start of the twisting motion, the twisting hook is closed so as to grasp a part of the wire ring by the forward movement of the sleeve due to the forward rotation of the hook drive motor, and then the forward rotation causes the wire ring to be twisted multiple times. The diameter is reduced and wound around the outer periphery of the material to be bound. After the twisting operation is completed, the twist hook is opened by the reverse rotation of the hook drive motor to release the wire loop. The torsion hook is then reversed to the initial angular position and then retracted to the standby position. As a result, the binding machine completes one cycle of the binding work.

According to the binding machine of Japanese Patent Application No. 4-40687, the sleeve for controlling the opening / closing and rotation of the twist hook is connected to the hook drive shaft through the ball loosely fitted in the spiral groove. When its rotation is blocked, moves forward by the normal rotation of the hook drive shaft, and moves backward by reverse rotation of the hook drive shaft. Therefore, if the twisting hook is caught on the wire ring wound around the outer periphery of the material to be bound after the twisting and the reverse rotation is prevented, the sleeve waits in the open state without returning to the initial angle position. It retreats to the position. When the sleeve retracts to the standby position, the hook drive motor stops and one bundling cycle is completed. Therefore, the twist hook starts the next cycle of the binding work at a position deviated from the initial angle position.

When the hook drive motor is started at the start of the next cycle of the binding work, the hook drive shaft also starts to rotate normally. At this time, the sleeve does not follow the rotation of the hook drive shaft due to its inertia at rest, and is pushed forward in the axial direction through the balls in the spiral groove. As a result, the twist hook that is out of the initial angular position does not face a part of the wire ring at a right angle, and it may be impossible to grasp a part of the wire ring. In this case, the twisting hook cannot perform twisting work, and the binding machine causes a binding error.

Therefore, an object of the present invention is to secure a part of the wire loop formed around the material to be bound by the twist hook even when the twist hook is in the standby position with the twist hook deviated from the initial angular position. It is to provide a twisting hook actuating mechanism of a binding machine that can be grasped in detail.

[0010]

[Means for Solving the Problems]

 According to the present invention, a wire is continuously supplied to an arc-shaped guide arranged at the front end of the binding machine body, and the wire fed from the tip of the arc-shaped guide is wound around the material to be bound to form a wire ring. In a binding machine that binds materials to be bound by grasping and twisting a part of this wire ring with a twist hook driven by a hook drive motor, a hook is attached to the front end of the hook drive shaft rotated by the hook drive motor. The support shaft is coaxially and rotatably coupled to each other, the spiral groove is formed on the outer peripheral surface of the hook drive shaft, the sleeve is externally fitted to the hook drive shaft and the twist hook support shaft, and the sleeve is hooked. It is rotatable in the spiral groove range and movable in the axial direction with respect to the drive shaft, and is rotationally integrated with the hook support shaft and movable in the spiral groove range in the spiral groove range. A spherical ball receiving portion that engages with the spiral groove is formed, and a twisting hook that is opened and closed by axial movement of the sleeve with respect to the hook drive shaft is pivotally supported by the hook support shaft, and the outer peripheral surface of the sleeve has its peripheral surface. A plurality of protrusions are formed in the direction, and a forward rotation stopper and a reverse rotation stopper are arranged on the binding machine body near the outer peripheral surface of the sleeve, and engage with the protrusions to prevent forward rotation and reverse rotation of the sleeve, and to drive the hook. A control device for controlling the start and stop of the motor, which controls the start of the hook drive motor so that the hook drive shaft rotates forward with a torque smaller than the static friction of the sleeve. The sleeve rotates forward with the hook drive shaft, the projection engages the forward rotation stopper to position the torsion hook at the initial angular position, and then the hook drive shaft rotates further forward. Then, the sleeve is advanced by the engagement of the protrusion and the forward rotation stopper, and the twist hook is closed in the direction to grasp the wire ring at the initial angular position, and the protrusion is aligned at the front end of the axial movement range of the sleeve. It is characterized in that the sleeve and the hook drive shaft are integrally rotated in the forward direction after being removed from the rotation stopper, and when the hook drive shaft is rotated in the reverse direction, the protrusion and the reverse rotation stopper are engaged to retract the sleeve to the standby position.

[0011]

[Operation and effect of the device]

 According to the present invention, the rotation at the time of starting the hook drive motor is the speed at which the hook drive shaft is normally rotated with a torque smaller than the static friction of the sleeve, so that relative rotation due to inertia between the hook drive shaft and the sleeve occurs. do not do. The forward rotation of the hook drive shaft causes the sleeve to forwardly rotate, and after moving the torsion hook to the initial angular position, the protrusion is engaged with the forward rotation stopper to stop the forward rotation, move forward, and close the torsion hook. At this time, the twist hook faces the wire ring at a right angle, and the wire ring is reliably gripped. As a result, the occurrence of a binding error is eliminated.

[0012]

【Example】

 FIG. 1 shows the internal structure of the binding machine. A substantially T-shaped main body 1 has a binding wire 3 wound around a bobbin 2 arranged at the rear end (the left end in FIG. 1) of the main body 1 and a straight guide 4 arranged at the upper end of the main body 1. , A wire supply mechanism a that is arranged at the front end of the main body 1 (the right end in FIG. 1) and that continuously supplies the curved guide 5 having an arc shape, and a bundled material 6 (for example, a plurality of bundled materials) fed from the front end of the curved guide 5. (A rebar, etc.) of a wire loop 3a formed by winding a plurality of times around the wire loop 3a, and a twisting hook 8 grasps and twists the wire loop 3a, a trigger switch 9, a wire supply mechanism a and a wire twisting mechanism b. A control device (for example, a microcomputer chip) that controls the rotations of the wire feed motor 10 and the hook drive motor 7 of the wire supply mechanism a and the wire twisting mechanism b based on signals from a sensor provided on the And provided It has been.

The wire supply mechanism a has a wire feed motor 10 which is an ordinary DC motor provided inside the rear end of the main body 1. The drive shaft of the wire feed motor 10 is connected to the wire feed drive roller 13 via a reduction gear 11. The wire feed drive roller 13 cooperates with a wire feed driven roller (not shown) to feed the wire 3 from the bobbin 2 to the linear guide 4.

The curved guide 5 has an arc-shaped fixed frame 14. As shown in FIGS. 1 and 2, the fixed frame 14 includes a frame main body 14a having a U-shaped cross section, and a frame main body 14a at a rear portion in the wire traveling direction and a front portion in the wire traveling direction of the frame main body 14a. It comprises a spring bearing 14b facing the inner surface. A movable plate 16 whose overall shape is substantially the same as that of the frame body 14a is arranged between the frame body 14a and the spring receiver 14b. The movable plate 16 is biased by a compression coil spring 15 provided between the spring receiver 14b and the movable plate 16 so as to be pressed against the frame body 14a. Near the inner surface of the movable plate 16, an arc-shaped guide groove 17 that is opened laterally (on the side of the frame body 14a) is formed. When the wire 3 is guided, the guide groove 17 forms a wire guide passage whose side is closed by the frame body 14a.

When the wire 3 passes through the guide groove 17, the wire 3 is plastically deformed in an arc shape, is fed out from the front end of the bending guide 5 and forms a ring of ring around the material to be bound 6, and the bending guide 5 is again formed. A plurality of windings (for example, three times) of the wire ring 3a is formed around the material to be bound 6 so as to enter the guide groove 17 from the rear end of the cable 5. At this point, the wire 3 is cut by the wire cutting mechanism c described later. After cutting the wire 3, the wire ring 3a tilts the movable plate 16 against the spring force of the compression coil spring 15 to a position indicated by a broken line by a worker pulling the binding machine away from the material to be bound 6, and guides it. The groove 17 is opened to the side and separated from the bending guide 5.

As shown in FIG. 1, a wire cutting mechanism c is arranged above the front end of the main body 1. A shearing cutter 18 is arranged at a connecting portion between the linear guide 4 and the curved guide 5. The shearing cutter 18 is rotated by a rod 19 extending along the linear guide 4 and a link plate 20 connected to the rear end of the rod 19 so that the rear end of the curved guide 5 and the front end of the linear guide 4 are rotated. The wire 3 is sheared in cooperation with the wire guide 40 disposed therebetween. The link plate 20 is formed with an operating piece 21 extending downward and operatively linked to the wire twisting mechanism b.

The rotation speed of the reduction gear 11 is detected by a wire feed amount sensor 22 including a magnet 22a fixed to the outer periphery of the reduction gear 11 of the wire feed motor 10 and a hall element 22b fixed to the main body 1. To be done. The wire feed amount sensor 22 outputs a predetermined wire feed amount detection signal when the feed amount of the wire 3 reaches a predetermined amount (that is, a predetermined rotation speed of the reduction gear 11). When the control device receives the predetermined wire feed amount detection signal, the control device stops the wire feed motor 10 and starts the hook drive motor 7 of the wire twisting mechanism b by the start control.

The wire twisting mechanism b moves the twisting hook 8 in the axial direction between the standby position and the operating position by the hook drive motor 7. The twisting hook 8 of the wire twisting mechanism b advances from the standby position to the operating position while the hook driving motor 7 is rotating in the normal direction, grasps and twists a part of the wire ring 3a, while the hook driving motor 7 rotates in the reverse direction. While doing so, it retreats from the operating position to the standby position and releases the twisted wire loop 3a.

The wire twisting mechanism b includes a hook drive shaft 24 (see FIG. 3) connected to a drive shaft of a DC motor type hook drive motor 7 arranged substantially in the center of the main body 1 via a reduction mechanism 23. At the front end of the hook drive shaft 24, there is provided a hook support shaft 25 which is coaxial with the hook drive shaft 24 via a ball connecting mechanism 24a composed of a spherical ball and an annular groove, and which is integrally rotatably moved forward and backward. The tip portion of the hook support shaft 25 is formed as a yoke, and the pivot shaft 8a pivotally supports the substantially L-shaped torsion hook 8 so as to be openable and closable. A sleeve assembly 26 is fitted onto the outer peripheral portion of the connecting portion between the hook drive shaft 24 and the hook support shaft 25. As shown in FIG. 1, below the sleeve assembly 26, a forward rotation stopper 27 and a reverse rotation stopper 28, which engage with the protrusion 34 of the sleeve assembly 26, are arranged in the main body 1. . As shown in FIG. 3, a spiral groove 29 is formed on the outer peripheral surface of the tip end portion of the hook drive shaft 24 within a certain range in the axial direction of the hook drive shaft 24. A long hole 30 is formed at the center of the torsion hook 8.

The sleeve assembly 26 has a structure in which an outer sleeve 26a and an inner sleeve 26b inserted in the outer sleeve 26a are integrally pin-coupled (not shown). The sleeve assembly 26 is rotatable and forward / backward with respect to the hook drive shaft 24, while being integrally rotatable with the hook support shaft 25 and forward / backward.

A ball accommodating portion 39 for accommodating two balls 31 loosely fitted in the spiral groove 29 at circumferentially opposite positions of the inner sleeve 26b is formed near the rear end of the inner sleeve 26b. ing. The ball accommodating portion 39 has a structure in which a retaining ring is fitted in circular holes formed at positions facing each other in the circumferential direction of the inner sleeve 26b. At the tip of the outer sleeve 26a, a pair of notches 33 that allow the torsion hook 8 to be opened and closed are formed at positions facing each other in the circumferential direction of the outer sleeve 26a. A claw 26c is formed at the tip of the outer sleeve 26a to cooperate with the tip of the torsion hook 8 to grasp the wire ring 3a.

As best shown in FIG. 3B, a plurality of (eg, four) projections 34 are provided on the outer peripheral surface of the rear end portion of the outer sleeve 26a at equal intervals in the circumferential direction. There is. Only one protrusion 34a is longer than the other three protrusions 34b in the axial direction of the sleeve assembly 26. The forward rotation stopper 27 and the reverse rotation stopper 28 are attached to the main body 1 via a bracket 35. As shown in FIG. 4 (b), the forward / reverse stoppers 27 and 28 are pivotally movable in the closing directions, and are biased in the opening directions by torsion coil springs. The reverse rotation stopper 28 is located axially forward of the sleeve assembly 26 with respect to the forward rotation stopper 27.

The protrusion 34 rides over the forward rotation stopper 27 when the sleeve assembly 26 rotates in the reverse direction, and engages with the forward rotation stopper 27 when the sleeve assembly 26 rotates in the forward direction, so that the sleeve assembly 26 rotates normally. Prevent. On the other hand, the protrusion 34 engages with the reverse rotation stopper 28 when the sleeve assembly 26 rotates in the reverse direction, and prevents the sleeve assembly 26 from rotating in the reverse direction, while overcoming the normal rotation stopper 27 when the sleeve assembly 26 rotates in the normal direction.

When the wire twisting mechanism b is in the standby position and the hook drive shaft 24 rotates in the normal direction, the projection 34a engages with the normal rotation stopper 27 to prevent the sleeve assembly 26 from rotating in the normal direction. For this reason, the sleeve assembly 26 advances together with the pair of balls 31 from the standby position to the operating position, during which the torsion hook 8 is pivoted in the direction of closing with respect to the leg 26c to partially remove the wire ring 3a. Figure out At this time, the pair of balls 31 are at the front end of the spiral groove 29, and the forward rotation stopper 27 and the projection 34a are disengaged. After that, the hook drive shaft 24 rotates forward together with the sleeve assembly 26, and the twist hook 8 twists the wire ring 3a. When the hook drive motor 7 is rotated in the reverse position in the operating position, one of the protrusions 34 first engages the reverse rotation stopper 28 to prevent the sleeve assembly 26 from rotating.

As shown in FIG. 1, a bulging plate 37 bulging in the radial direction is fixed to the rear end of the sleeve assembly 26. A magnet 38 a is fixed to the rear surface of the overhang plate 37. On the other hand, the hall element 38b is arranged on the front surface of the cover of the speed reduction mechanism 23. A standby position sensor 38 is configured by the magnet 38a and the hall element 38b. The standby position sensor 38 detects that the sleeve assembly 26 (that is, the twist hook 8) is in the standby position. The overhanging plate 37 is engageable with the operating piece 21 of the link plate 20.

The operation of the torsion hook operating mechanism will be described below. When the operator arranges the curved guide 5 around the material to be bound 6 and presses the trigger switch 9, the wire feed motor 10 is activated, and the wire feeding mechanism a causes the wire 3 of a predetermined amount to be wrapped around the material to be bound 6. To form a wire ring 3a wound a plurality of times. Then, the hook drive motor 7 is activated by the sequence set by the control device to rotate normally.

The control device activates the hook drive motor 7 by the following method. That is, the hook drive motor 7 is started and stopped by turning on / off a switching element that receives a drive signal from the control device and performs a switching operation. When the hook drive motor 7 is started, a drive signal having a pulse waveform is output from the control device to the switching element, and the switching element is turned on / off with an extremely short width to supply a small effective power to the hook drive motor 7. As shown by the solid line in FIG. 11C, the rotation speed of the hook drive motor 7 is reduced as compared with the case without the start control shown by the alternate long and short dash line. For example, after the start signal of the hook drive motor 7 is output, the switching element is changed so as to output a pulse waveform drive signal having an on time width of 45 μs and an off time width of 200 μs for about 0.1 seconds. To drive. As a result, the hook drive shaft 24 rotates with a torque smaller than the static friction of the sleeve assembly 26, the sleeve assembly 26 also rotates integrally with the hook drive shaft 24, and the torsion hook 8 rotates up to about 180 °. It The torsion hook 8 is positioned at the initial angular position by the engagement between the protrusion 34a and the forward rotation stopper 27 during the rotation thereof. After 0.1 second has elapsed from the activation of the hook drive motor 7, a continuous ON signal is output from the control device to the switching element, and the hook drive motor 7 is normally rotated. After that, the wire twisting mechanism a operates normally.

The sleeve assembly 26 is prevented from rotating due to the engagement between the protrusion 34 a and the normal rotation stopper 27, and moves forward. As the sleeve assembly 26 advances, the torsion hook 8 closes against the leg 26c and grasps a portion of the wire annulus 3c. During this time, the projecting plate 37 also moves forward, and the link plate 20 is rotated via the operating piece 21. As a result, the shearing cutter 18 is rotationally driven with respect to the wire guide 40, the wire guide 40 and the wire passage in the shearing cutter 18 are displaced from each other, and the wire 3 is located immediately before the rear end of the bending guide 5. Sheared.

When the ball 31 reaches the front end of the spiral groove 29, the protrusion 34 a of the sleeve assembly 26 is disengaged from the forward rotation stopper 27. After that, the sleeve assembly 26 rotates forward with the hook drive shaft 24, and the twist hook 8 twists the wire ring 3a a plurality of times. During this time, the protrusion 34 of the sleeve assembly 26 allows the torsion hook 8 to rotate in the normal direction while overcoming the reverse rotation stopper 28.

When the wire is twisted a predetermined number of times, the load torque of the twist hook drive motor 7 rapidly increases. This sudden increase in load torque is detected by a load torque sensor (not shown). Upon receipt of this load torque detection signal, the control device reverses the torsion hook drive motor 7. As a result, the sleeve assembly 26 is also rotated integrally with the hook drive shaft 24. However, any one protrusion 34 of the sleeve assembly 26 abuts the reversing stopper 28 within the range of ¼ rotation of the sleeve assembly 26, and prevents the reversing of the sleeve assembly 26. In the case of the present embodiment, four protrusions 34 are provided at equal intervals in the circumferential direction of the sleeve assembly 26, so the maximum reverse rotation amount of the sleeve assembly 26 is 90 °. Therefore, due to the reverse rotation of the twist hook 8, the twisted part of the wire ring 3a is not excessively twisted back.

By blocking the reverse rotation of the sleeve assembly 26, the sleeve assembly 26 begins to retract and first opens the torsion hook 8 (see FIG. 7). When the sleeve assembly 26 is further retracted, the protrusion 34b is disengaged from the reverse rotation stopper 28, and the sleeve assembly 26 is reversed until the projection 34a is engaged with the reverse rotation stopper 28. When the projection 34a engages the reverse stopper 28 (see FIG. 8), the torsion hook 8 returns to the initial angular position, and thereafter, the sleeve assembly 26 retracts to the standby position (see FIG. 9). This is detected by the standby position sensor 38. The control device stops the torsion hook drive motor 7 in response to the detection signal from the standby position sensor 38. Even when the torsion hook 8 does not return to the initial angular position, as described above, the torsion hook 8 returns to the initial angular position by the start control of the hook drive motor 7 in the cycle after the binding work.

In the above embodiment, the torsion hook 8 is substantially L-shaped, but as shown in FIG. 10, it has a symmetrical shape and uses a pair of torsion hooks 8a that open and close to each other. May be.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view of the internal structure of a binding machine having a twist hook actuating mechanism according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

3 (a) and 3 (b) are respectively a longitudinal sectional view and a lateral sectional view of a main part of the wire twisting mechanism of the binding machine in FIG.

4A and 4B are respectively a side view and a front view of the wire twisting mechanism immediately after starting at a standby position.

5A and 5B are a side view and a front view, respectively, of a wire twisting mechanism in which an operating position is reached and a wire ring is grasped.

6 (a) and 6 (b) are a side view and a front view of the wire twisting mechanism immediately after starting the reverse rotation of the hook drive motor after the wire twisting operation is completed.

7 (a) and 7 (b) are respectively a side view and a front view of the wire twisting mechanism with a twist hook opened.

8A and 8B are respectively a side view and a front view of the wire twisting mechanism with the twisting hook returned to the initial angular position.

9A and 9B are a side view and a front view, respectively, of the wire twisting mechanism in a state of returning to the standby position.

FIG. 10 is a plan view of a twist hook according to another embodiment.

11 (a), (b) and (c) are respectively,
FIG. 7 is a waveform diagram of a start signal of the hook drive motor, a drive signal of the hook drive motor, and a rotation speed of the hook drive motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bundler main body 3 Wire 3a Wire ring 5 Circular guide 6 Bundled material 7 Hook drive motor 8 Torsion hook 24 Hook drive shaft 25 Hook support shaft 26 Sleeve assembly 27 Forward rotation stopper 28 Reverse rotation stopper 29 Spiral groove 31 Spherical ball 34 Protrusion 39 Ball storage

Claims (1)

[Scope of utility model registration request] 1. A wire is continuously supplied to an arc-shaped guide arranged at a front end of a binding machine body, and a wire fed from a tip of the arc-shaped guide is wound around a material to be bound to form a wire ring. In a binding machine for binding a material to be bound by grasping and twisting a part of the wire ring with a twist hook driven by a hook drive motor, a hook support shaft is attached to a front end of a hook drive shaft rotated by the hook drive motor. Are coaxially and rotatably connected to each other, a spiral groove is formed on the outer peripheral surface of the hook drive shaft, a sleeve is externally fitted on the hook drive shaft and the twist hook support shaft, and the sleeve is attached to the hook drive shaft. On the other hand, it is rotatable and axially movable within the range of the spiral groove, is rotationally integrated with the hook support shaft, and axially movable within the range of the spiral groove. , A spherical ball accommodating portion that engages with the spiral groove is formed, and a torsion hook that is opened and closed by axial movement of the sleeve with respect to the hook drive shaft is pivotally supported by the hook support shaft, and the outer peripheral surface of the sleeve has a circumferential direction. A plurality of protrusions are formed on the hook, and a forward rotation stopper and a reverse rotation stopper are arranged on the binding machine body in the vicinity of the outer peripheral surface of the sleeve, and engage with the protrusions to prevent the forward rotation and the reverse rotation of the sleeve. Is a control device for controlling the start and stop of the hook drive motor so that the hook drive shaft is normally rotated with a torque smaller than the static friction of the sleeve. Forward rotation with the hook drive shaft, the projection engages the forward rotation stopper to position the torsion hook at the initial angular position, and then
In the process of the hook drive shaft further rotating in the forward direction, the sleeve is advanced by the engagement of the protrusion and the forward rotation stopper, and the twist hook is closed in the direction to grasp the wire ring at the initial angular position, and the axial movement range of the sleeve is adjusted. At the front end, the projection is removed from the normal rotation stopper, the sleeve and the hook drive shaft are integrally rotated in the forward direction, and when the hook drive shaft is rotated in the reverse direction, the projection and the reverse rotation stopper are engaged to retract the sleeve to the standby position. A torsion hook actuation mechanism characterized in that