JP3598784B2 - 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. Therefore, as shown in FIG. The diameter of the wire 26 expands, and the wire 26 becomes 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 that winds around a reinforcing bar and twists and binds with a torsion hook, swings in accordance with forward rotation and reverse rotation of a feed motor that feeds the binding wire from the wire reel. The moving lever is reciprocally swingable within a certain range, and the brake means moves in a direction away from the peripheral edge of the wire reel and in a direction engaging with the peripheral edge in accordance with the swing of the swing lever. It is allowed, by reverse rotation after feeding the tie wire by a predetermined length by the forward rotation of the feed motor, the upper Symbol wire reel the braking means Is engaged with the edge braking the rotation of the wire reel, during forward rotation of the feed motor, characterized in that by operating in a direction away said brake means from the periphery of the wire reel to release said 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 formed with a torsion hook 8 that is engaged with the wire 33 wound around the reinforcing bar 7 and twists. The torsion hook 8 is configured to be driven by a motor 9. .
[0008]
As shown in FIG. 2, the feed means 5 is composed of a pair of feed gears 5a, 5b, sandwiches the wire 3 between the peripheral surfaces of these feed gears 5a, 5b, and feeds the feed gears 5a, 5b by a feed motor. By driving the wire 5b, the wire 3 is rewound from the wire reel 2 and sent forward.
[0009]
The wire reel 2 includes a drum 2a and a flange 2b, and is removably stored in a storage unit 10 formed at one rear side of the binding machine main body 1.
[0010]
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.
[0011]
Next, a brake mechanism for the wire reel 2 is disposed between the wire feeding means 5 and the wire reel 2. That is, as shown in FIG. 1, groove-shaped engaging portions 11 are cut out at regular intervals on the peripheral portion of the flange 2b of the wire reel 2, and face the engaging portions 11 as shown in FIG. In the position, the central part of the brake means 12 is arranged rotatably by the support shaft 13. One end of the brake means 12 is disposed so as to be able to engage with the engaging portion 11 of the wire reel 2, and the other end is connected to a swing lever 16 mounted on the same coaxial 15 as one of the feed gears 5 a via a connecting link 14. are doing. As shown in FIGS. 4A and 4B, the base of the swing lever 15 is overlapped on the side surface of the feed gear 5a, and a plurality of (in this example) The four recesses 17 and the spring receiving groove 19 of the spring 18 are formed, and approximately half of the steel ball 20 is engaged with the concave portion 17, and the remaining portion is engaged with the spring receiving groove 19. As described above, since the steel ball 20 is engaged with the swing lever 16, the concave portion 17 of the feed gear 5 a, and the spring receiving groove 19, when the feed gear 5 a rotates, the swing lever 16 also normally rotates in the same direction. Move.
[0012]
On both sides of the swing lever 16, there are disposed detents 21 for restricting the rotation range of the swing lever 16. When the swing lever 16 engages with the detent 21, it cannot rotate any further.
[0013]
In the brake mechanism having the above configuration, when the feed motor rotates forward as shown in FIG. 2, the feed gears 5a and 5b rotate in the direction of the arrow, whereby the wire 3 on the wire reel 2 is rewound and sent forward. It is. When the feed gears 5a and 5b rotate, the swing lever 16 also rotates in the same direction, so that the connecting link 14 moves as shown in the figure and rotates the brake means 12 about the support shaft 13. At this time, since the tip of the brake means 12 moves away from the wire reel 2, the brake does not operate. In addition, the forward rotation of the feed motor causes the swing lever 16 to engage with the detent 21 while rotating in conjunction with the feed gear 5a and cannot rotate any more, whereas the feed gear 5a rotates. 4A, and the steel ball 20 of FIG. 4A engaged with the both escapes to the feed gear 5a side in accordance with the relative rotation. Therefore, only the feed gear 5a rotates, and the swing lever 16 stops.
[0014]
Next, after the wire 3 having a predetermined length is fed, the feed motor rotates reversely. As a result, the feed gears 5a and 5b also rotate in the reverse direction as indicated by the arrows, so that the steel ball 20 is engaged with the swing lever 16 and the feed gear 5a. Accordingly, the swing lever 16 also rotates in the opposite direction, and the connecting link 14 also moves as shown in FIG. 3 to rotate the brake means 12 in the opposite direction about the support shaft 13. At this time, the tip of the brake means 12 moves toward the wire reel 2 and engages with the engaging portion 11 (see FIG. 1) of the wire reel 2, so that the brake is operated on the wire reel 2 and the wire reel 2 is operated. The rotation of 2 stops suddenly. Also, when the swing lever 16 engages with the detent 21 during the rotation of the feed motor in the reverse direction, the steel ball 20 escapes to the feed gear 5a side. Therefore, only the feed gear 5a rotates, and the swing lever 16 stops.
[0015]
When the feed motor rotates forward again, the brake by the brake means 12 is released as described above, and the wire 3 is fed.
[0016]
As described above, almost simultaneously with the completion of the feeding of the wire 3 having the predetermined length, the feeding motor 9 is rotated in the reverse direction, the brake means 12 is operated, the brake is applied to the wire reel 2, and the rotation is suddenly stopped. Therefore, the diameter of the wire 3 does not expand due to excessive rotation of the wire reel 2, the wire 3 can always be smoothly fed, and disadvantages such as an increase in current consumption, heat generation of the motor 9, and a reduction in speed are satisfactorily prevented. can do.
[0017]
In each of the above-described examples, the brake is not limited to the one in which the brake means 12 is engaged with the engagement portion 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 plan view schematically showing a brake mechanism of a wire reel of the reinforcing bar binding machine. FIG. FIGS. 4 (a) and 4 (b) are longitudinal sectional views of a feed gear and a swing lever and a plan view of a swing lever. FIG. 5 is an explanatory view showing a state of a conventional wire reel at the end of wire feed. [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Bundling machine main body 2 Wire reel 3 Bundling wire 5 Feeding means 12 Brake means 16 Swing lever

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 ,
The swing lever can reciprocate within a certain range according to the forward rotation and the reverse rotation of the feed motor that sends out the binding wire from the wire reel, and the brake means operates the wire reel in accordance with the swing of the swing lever. Are linked to move in a direction away from the peripheral edge and in a direction engaging with the peripheral edge,
Is reversely rotated after feeding the tie wire by a predetermined length by the forward rotation of the feed motor, brakes the rotation of the wire reel is engaged with the peripheral edge portion of the upper Symbol wire reel the brake means, A brake mechanism for a wire reel in a rebar tying machine, characterized in that when the feed motor rotates forward, the brake means is operated in a direction away from the peripheral edge of the wire reel to release the brake.

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