JP3598785B2 - Brake mechanism of wire reel in rebar binding machine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a brake mechanism for stopping the rotation of a wire reel after sending out a binding wire of a predetermined length in a rebar binding machine.
[0002]
[Prior art]
In general, a reinforcing bar binding machine winds a binding wire of a predetermined length around a crossed rebar and twists the wire with a torsion hook to bind the wire. The wire is wound around a wire reel attached to the rear part of the binding machine main body. At the time of wire feeding, the wire is sent forward by wire feeding means. At this time, the wire reel rotates and the wire is unwound. The feed amount of the wire is precisely controlled, and when a predetermined length of wire is fed, the wire feed stops suddenly.
[0003]
[Problems to be solved by the invention]
However, according to the wire feed mechanism, when the feed of a predetermined length is performed, the feed of the wire is suddenly stopped, but the wire reel continues to rotate excessively due to inertia, so that the wire on the wire reel 20 as shown in FIG. Since the diameter of the wire 21 is expanded, the wire 21 is entangled and cannot be smoothly unwound, which may hinder the next wire feeding.
[0004]
As a countermeasure against this, it is conceivable to always apply a brake to the wire reel with a leaf spring or the like to prevent the coasting rotation of the wire reel, but in this case, the load of feeding increases, so the current consumption increases, The motor generates heat, causing problems such as a reduction in speed.
[0005]
SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a wire reel brake mechanism in a rebar tying machine capable of applying a brake to the rotation of the wire reel almost immediately after a predetermined wire feed is completed.
[0006]
[Means for Solving the Problems]
In order to solve the above problem, the wire reel brake mechanism in the reinforcing bar binding machine according to the present invention sends a binding wire forward from the binding machine main body from a wire reel rotatably provided at a rear portion of the binding machine main body and intersects. In a wire reel brake mechanism of a reinforcing bar binding machine, which is wound around a reinforcing bar and then twisted and bound with a torsion hook, an extension of a rotating shaft of a helical gear meshed and connected to a torsion motor driving the torsion hook. A brake means engageable with the peripheral portion of the wire reel is disposed on the upper side, and the brake means is urged by a spring in a direction away from the wire reel, and the thrust load generated when the torsional motor rotates forward is removed. The gear is moved in the axial direction of the rotating shaft, and the brake means is pushed to engage with the peripheral portion of the wire reel to apply a brake. When you reverse rotation to move in the reverse direction helical gear is moved away the brake means from the wire reel, characterized in that to release the brake.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
1 and 2 are a side view and a plan view, respectively, showing an outline of a binding mechanism in a reinforcing bar binding machine. In the figures, reference numeral 1 denotes a binding machine main body, and 2 denotes a wire reel rotatably provided at a rear portion of the binding machine main body 1. Is shown. A passage (not shown) for the wire 3 is formed in the binding machine main body 1, a feeding means 5 for sending the wire 3 forward is arranged in the passage, and the wire 3 is formed in a loop shape at a front portion of the binding machine main body 1. A guide 6 is provided to guide the user to bend. Further, the binding machine main body 1 is provided with a torsion hook 8 which is engaged with the wire 3 wound around the reinforcing bar 7 and twists. The torsion hook 8 is configured to be driven by a motor 9. . The feeding means 5 is also driven by another motor (not shown).
[0008]
The rebar tying machine sends out a wire 3 of a predetermined length from the wire reel 2 by the feeding means 5 and winds the wire 3 around the crossed rebar 7, and the torsion motor 9 is operated based on a signal from the feeding means 5. It operates to drive the torsion hook 8 to twist and bind the wire 3.
[0009]
Note that the torsion hook 8 is configured to initially rotate forward, advance to the wire loop and twist, and after the torsion is completed, reversely rotate and retract to the original position.
[0010]
Next, the wire reel 2 is composed of a drum 2a and a flange 2b, and is removably stored in a storage section 10 formed at one rear side of the binding machine main body 1. A brake mechanism is arranged in the vicinity thereof. That is, as shown in FIG. 3 (a), engagement portions 11 are cut out at regular intervals on a peripheral portion of the flange 2b of the wire reel 2, and the brake means 12 is provided at a position opposed to the engagement portions 11. Is arranged. The brake means 12 is configured to engage and disengage with the engaging portion 11 of the wire reel 2 by the spring force of the tension spring 13 and the axial movement of the operating shaft 14. A helical brake gear 15 is fixed to the operating shaft 14. As shown in FIG. 4A, a hook driving helical gear 16 associated with the torsion hook 8 meshes with the brake helical gear 15, and the hook driving helical gear 16 has a torsion helical gear. And meshes with a helical gear 17 provided on the output shaft of the motor 9.
[0011]
In addition, 18a and 18b are thrust bearings. When the hook driving helical gear 16 rotates and the braking helical gear 15 rotates, a thrust load is generated, whereby the braking helical gear 15 moves in the axial direction together with the operating shaft 14. Then, the thrust bearing 18b on the side closer to the wire reel 2 moves in the direction in which the operating shaft 14 approaches the wire reel 2 and pushes the brake means 12, so that the tip of the thrust bearing 18b is engaged with the peripheral edge of the wire reel 2. Sometimes, the brake is arranged at a position corresponding to one side of the helical gear 15. The thrust bearing 18b on the side remote from the wire reel 2 is provided with the brake sleeve when the operating shaft 14 moves in the direction away from the wire reel 2 and the brake means 12 is separated from the wire reel 2. It is arranged at a position where the other side of the gear 15 hits. The spring force of the tension spring 13 is set to be smaller than the thrust load.
[0012]
In the brake mechanism having the above structure, when the wire reel 2 rotates and the wire 3 is fed by a predetermined length and then the torsional motor 9 rotates forward, as shown in FIGS. 3 (a) and 4 (a). The hook driving helical gear 16 rotates and the torsion hook 8 rotates, and at the same time, the braking helical gear 15 rotates forward, but the thrust load generated at this time causes the helical gear 15 to operate. The shaft 14 moves toward the wire reel 2 along the axial direction and pushes the brake means 12 against the spring force of the tension spring 13 so that its tip engages with the peripheral edge of the wire reel 2. Stops suddenly.
[0013]
After the torsion hook rotates and grasps and twists the wire 3, the torsion motor 9 rotates in reverse to remove the torsion hook 8 from the wire 3, but at the same time the helical gear 15 for braking also rotates in reverse, so that the thrust load is increased. 3 (b) and 4 (b), the helical gear 15 for brake and the operating shaft 14 move in the direction away from the wire 3, and the brake means 12 is released from the wire reel 2 by the tension spring 13 to release the brake. By repeating the above operation, it is possible to apply an abrupt brake to the wire reel 2 after rotation.
[0014]
As described above, almost simultaneously with the completion of the feeding of the wire 3 having the predetermined length, the torsion motor 9 is operated, and the brake means 12 is operated at the time of the forward rotation to apply a brake to the wire reel 2 and rotate the wire reel 2. Suddenly stops, so that the wire reel 2 does not rotate too much and the diameter of the wire 3 does not expand, the wire 3 can always be sent smoothly, and disadvantages such as an increase in current consumption, heat generation of the motor, and a decrease in speed are caused. It can be prevented well.
[0015]
Further, the torsion motor 9 rotates forward and backward to drive the torsion hook 8, and this is used to perform the brake and the release thereof, so that a special drive control mechanism is not required.
[0016]
In each of the above examples, the brake is not limited to the one in which the brake means 12 is engaged with the engagement portion 11 of the wire reel 2. For example, a configuration may be adopted in which a brake is applied by strongly pressing a part of the brake means configured in the same manner as described above against the periphery of the wire reel.
[Brief description of the drawings]
FIG. 1 is a vertical cross-sectional view of a side surface showing an outline of a reinforcing bar binding machine. FIG. 2 is a cross-sectional view of a plane showing an outline of the reinforcing bar binding machine. FIGS. 4 (a) and 4 (b) are explanatory views showing an operation mode of the brake mechanism when the brake is released. FIG. 5 is an explanatory view showing a conventional state of a wire reel at the time of braking. ]
2 Wire reel 3 Wire 9 Torsion motor 12 Brake means 14 Operating shafts 15, 16, 17 Helical gear

Claims (1)

After wound around the reinforcing bars crossed by feeding the binding wire in front of the binding machine body from a wire reel rotatably provided in the rear of the binding machine body, wire in the reinforcing bar binding machine for binding by twisting in the torsional hook In the reel brake mechanism ,
Brake means engageable with the peripheral edge of the wire reel is disposed on the extension of the rotation shaft of the helical gear meshed with the torsion motor driving the torsion hook, and the brake means is moved away from the wire reel. Along with biasing the spring,
Due to the thrust load generated when the torsional motor rotates forward, the helical gear moves in the axial direction of the rotating shaft, pushes the brake means and engages with the periphery of the wire reel to apply a brake,
When the torsional motor rotates in the reverse direction, the helical gear moves in the reverse direction to move the brake means away from the wire reel to release the brake, and the brake mechanism for the wire reel in the reinforcing bar binding machine is provided.

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