JP2660472B2 - Rebar bender - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforcing bar bender, and more particularly, to a reinforcing bar bender capable of reducing the size of the whole shape and achieving smooth bending of a deformed reinforcing bar.

[0002]

2. Description of the Related Art There is known a portable reinforcing bar bender configured to bend a bar-shaped material such as a reinforcing bar. This type of reinforcing bar bender generally includes a fixed roller that forms a bending center of the reinforcing bar to be processed, a bending roller that presses the reinforcing bar against the fixed roller, and a moving shaft that carries the bending roller, and includes a moving shaft. It has a rotating member for moving along a predetermined curved path and a supporting member for bearing the reaction force of the bending force applied to the reinforcing bar (for example, a flat square 4 mm).
17312, Japanese Utility Model Application No. 4-47819, Japanese Utility Model Application No. 2-57742, etc.).

[0003] In the reinforcing bar bender having such a configuration, the bending roller is concentrically held on the outer periphery of the moving shaft, and is moved along a curved path centered on the fixed roller with the turning movement of the turning member. . The outer peripheral surface of the bending roller comes into contact with a reinforcing bar inserted between the bending roller and the fixed roller, and presses the reinforcing bar against the fixed roller. As a result, a bending force about the fixed roller acts on the reinforcing bar, and the reinforcing bar is bent at a predetermined angle about the fixed roller.

[0004]

With respect to such a reinforcing bar bender, a reduction in the size of the entire apparatus has been strongly demanded in recent years. However, in order to reduce the distance between the center axis of the bending roller and the center axis of the fixed roller and to reduce the size of the entire apparatus, it is necessary to secure a sufficient space for inserting a reinforcing bar between the bending roller and the fixed roller. Therefore, the outer diameter of the bending roller must be set as small as possible.

However, in the rebar bender of such a design, the bending roller having a small diameter is difficult to rotate smoothly during bending of the deformed reinforcing bar, and a relatively large frictional resistance is generated at a contact portion between the bending roller and the deformed reinforcing bar. As a result, it has been found that if excessive bending is performed on the deformed rebar, excessive internal stress is generated in the deformed rebar, and in extreme cases, the rebar may be broken.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a reinforcing bar bender which can reduce the size of the entire apparatus and can achieve smooth bending of deformed reinforcing bars. It is in.

[0007]

SUMMARY OF THE INVENTION In order to attain the above object, the present invention provides a fixed roller for forming a bending center of a reinforcing bar to be machined, and a bending roller for pressing the reinforcing bar against the fixed roller. A moving shaft that carries the bending roller, a rotating member that supports the moving shaft and moves the moving shaft along a predetermined curved path, and bears a reaction force of a bending force applied to the rebar. A bending member provided with a supporting member that performs bending, wherein a center axis of the bending roller is eccentric outward in a bending radial direction with respect to a center axis of the moving shaft.

According to the above configuration of the present invention, the bending roller is eccentric with respect to the moving axis. Therefore, the outer diameter of the bending roller can be set to be considerably large while securing a sufficient space for inserting the reinforcing bar between the bending roller and the fixed roller. The inventor prototyped a reinforcing bar bender in which the eccentric distance between the bending roller and the moving shaft was set to about 24 mm and the outer diameter of the bending roller was set to about 92 mm according to the configuration of the present invention. The inventor of the present invention tried bending a deformed reinforcing bar using this reinforcing bar bender. As a result, the bending roller rotated as desired, the breakage of the reinforcing bar did not occur, and smooth bending of the deformed reinforcing bar was achieved.

In a preferred embodiment of the present invention, the moving shaft includes a shaft portion penetrating a top plate constituting a main body casing of the reinforcing bar bender, and a radially expanding portion extending radially above the top plate. A central axis of the enlarged diameter portion is eccentric outward in the bending radial direction with respect to a central axis of the shaft portion, and the bending roller is disposed concentrically on an outer periphery of the enlarged diameter portion. . According to this configuration, since the center axis of the bending roller can be decentered by deforming the moving shaft, a bending roller having a special shape is not required.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a reinforcing bar bender according to the present invention will be described below in detail with reference to the accompanying drawings. 1 and 2 are a plan view and a side view showing an embodiment of a reinforcing bar bender according to the present invention.

As shown in FIGS. 1 and 2, a reinforcing bar bender 1 is provided with a casing 2 formed substantially in a box shape as a whole.
An electric motor 3 disposed on a side of the casing 2;
An operation unit 4 for manually controlling the operation of the electric motor 3 is provided. A fixed roller 5 serving as a bending center axis of the reinforcing bar W to be processed and a guide 6 for supporting the reinforcing bar W from a side surface are arranged at predetermined positions on a top plate 7 of the casing 2. The top plate 7 is formed with a curved groove 8 extending in a substantially semicircular shape with a predetermined radius of curvature around the fixed roller 5, and a moving shaft 9 extending upward through the curved groove 8 is provided with a bending roller 1.
0 is attached. The bending roller 10 applies a bending load to the reinforcing bar W by the movement of the moving shaft 9 along the curved groove 8.

The operation unit 4 includes a start switch 11 for connecting a main power supply, a pilot lamp 12 for displaying a start state, a start button 13 for starting the electric motor 3, and an emergency stop button 14 for emergency stop. . The operation unit 4 also includes a bending angle adjustment dial 15 for regulating the movement of the bending roller 10 and adjusting the bending angle of the reinforcing bar W.

FIGS. 3 and 4 are a longitudinal sectional view and a partially enlarged sectional view of the reinforcing bar bender shown in FIG. As shown in FIG. 3, the output shaft 20 of the electric motor 3 extends into the casing 2, and the worm gear formed at the tip of the rotation shaft meshes with the worm wheel gear 21. The worm wheel gear 21 is fixed to a vertical first shaft 23 rotatably supported by the casing 2. The pinion gear 22 is fixed to the first shaft 23 adjacent to the worm wheel gear 21, and the pinion gear 22 meshes with the large gear 24. The large gear 24 is rotatably supported by a vertical second shaft 26 rotatably supported by the casing 2, and is selectively connected to the second shaft 26 by an electromagnetic clutch 25.

An output gear 26 a formed at the upper end of the second shaft 26 meshes with the intermediate gear 27. Intermediate gear 27
Is fixed to a vertical third shaft 28 rotatably supported by the casing 2. The pinion gear 29 is the third shaft 28
And is meshed with the roller drive gear 30. Further, a spiral spring 40 is arranged around the third shaft 28. The inner end of the spiral spring 40 is fixed to the third shaft 28 by a screw or a bolt 41, and the outer end of the spiral spring 40 is fixed to the side wall of the casing 2 by a screw or a bolt (not shown). The spiral spring 40 biases the third shaft 28 so as to hold the bending roller 10 at the initial position.

The roller drive gear 30 is rotatably supported by a vertical fourth shaft 31 supported by the casing 2. A sprocket 32 is rotatably supported by a lower end portion of the fourth shaft 31, and the sprocket 32 includes a support arm 33 extending laterally. The sprocket 32
A pair is formed with an operation sprocket (not shown) rotated by the adjustment dial 15, and a roller chain 36 is wound around the sprocket 32 and the operation sprocket. A limit switch 34 is attached to the tip of the support arm 33, and the limit switch 34
It has a contact 34a that can contact the raised portion 30a of the roller drive gear 30.

As shown in FIG. 4, the fourth shaft 31 is
, And extends upward, and a fixed roller 5 is attached to an upper end portion thereof. The fixed roller 5 is disposed concentrically around the fourth shaft 31 and is rotatably supported by the fourth shaft 31. The bolt 52 is connected to the fourth shaft 31 via the holding plate 51.
And the fixed roller 5 is carried on the fourth shaft 31. A radial groove 53 is formed in the lower end surface of the fixed roller 5.
Are formed, and the groove 53 receives the projection 54 formed on the top plate 7. The projection 54 engages with the groove 53 to inhibit the rotation of the fixed roller 5.

As shown in FIG. 3, the limit switch 30
A moving shaft 9 is fixed to a peripheral area of the roller driving gear 30 located on the opposite side of the moving shaft 9, and the moving shaft 9 extends upward from the roller driving gear 30 and passes through the curved groove 8. As shown in FIG. 4, the moving shaft 9 has an enlarged diameter portion 91 above the top plate 7. The enlarged diameter portion 91 has an outer diameter considerably larger than the moving shaft 9, and the central axis 92 of the enlarged diameter portion 91 is
Are eccentric to the outside in the bending radial direction with respect to the center axis 93. The outer diameter of the enlarged diameter portion 91, the outer diameter of the bending roller 10, and the amount of eccentricity of the center axes 92 and 93 are, for example, about 79 mm, 92 mm.
mm and 24 mm, respectively.

The bending roller 10 is arranged concentrically around the enlarged diameter portion 91 and is rotatably supported by the moving shaft 9. Bolts 95 are fastened to the upper end axis of the enlarged diameter portion 91 via the holding plate 94, and the bending roller 10 is carried on the moving shaft 9. The reinforcing bar bender 1 configured as described above is operated as follows. Start switch 11 and start button 13
Is turned on, the electric motor 3 is operated, and the electromagnetic clutch 25 is engaged. The driving torque of the electric motor 3 is controlled by a plurality of gears 21, 22, 24, 26 a, 27, 29.
Is transmitted to the roller drive gear 30 at a predetermined reduction ratio via a power transmission mechanism including The roller drive gear 30 has a fourth
The movable shaft 9 and the bending roller 10 are rotated around a shaft 31.
Is moved as shown by the arrow in FIG. The speed is reduced at a predetermined gear ratio and transmitted to the roller drive gear 30. With the rotation of the roller drive gear 30, the moving shaft 9 and the bending roller 1
0 is moved along the curved groove 8 as shown by the arrow in FIG. The bending roller 10 abuts on the reinforcing bar W and rolls on the reinforcing bar W while pressing it against the fixed roller 5. Since the fixed roller 5 regulates the movement of the reinforcing bar W on the opposite side of the bending roller 10, and the guide 6 supports the reinforcing bar W on the same side as the bending roller 10, the reinforcing bar W is as shown by a broken line in FIG.
It is bent around the fixed roller 5.

The limit switch 34 is connected to the adjustment dial 15
Is set at a position corresponding to the set angle by setting a predetermined angle, and when the roller drive gear 30 rotates by a predetermined angle, the raised portion 30a of the roller drive gear 30
Contacts the contact 34a of the limit switch 34.
As a result, the limit switch 34 deactivates the power supply circuits of the electric motor 3 and the electromagnetic clutch 25. As a result, the electric motor 3 stops, and the electromagnetic clutch 25 is released. Thus, when the electromagnetic clutch 25 is released, the second shaft 2
6, the intermediate gear 27, the third shaft 28, the pinion gear 29, and the roller drive gear 30 are in a floating state.

The spiral spring 40 entrained during the rotation of the roller drive gear 30 rotates the third shaft 28 in the reverse direction by the stored energy, and the second shaft 26 and the intermediate gear 27 associated with the third shaft 28. , The pinion gear 29 and the roller drive gear 30 are reversed. Thus, the roller drive gear 30
The moving shaft 9 and the bending roller 10 supported by the moving member are moved in the direction opposite to the arrow in FIG. 1 and return to the initial position.

In the reinforcing bar bender 1 configured as described above, the bending roller 10 is supported by the enlarged diameter portion 91, and the central axis 92 of the enlarged diameter portion 91 is bent in the bending radial direction with respect to the central axis 93 of the moving shaft 9. The bending roller 10 is eccentric outward, and the outside diameter of the bending roller 10 is set to a sufficient outside diameter to smoothly bend the deformed reinforcing bar. When the bending of the deformed reinforcing bar was tried with such a reinforcing bar bender 1, smooth rotation of the bending roller 10 during the bending process was ensured, and no breakage of the reinforcing bar occurred. Thus, the desired bending process was performed on the deformed reinforcing bar. Was completed.

In the rebar bender 1, a radially enlarged portion 91 that expands in the radial direction above the top plate 7 is provided above the moving shaft 9, and the central axis 92 of the radially enlarged portion 91 is moved to Since the bending portion 10 is decentered outward in the bending radial direction with respect to the center axis 93 of the shaft portion, the bending roller 10 can be arranged concentrically on the outer periphery of the large-diameter portion 91. Therefore, according to the reinforcing bar vendor 1,
The bending roller 10 can be decentered without making the bending roller 10 a special shape.

The preferred embodiment of the present invention has been described in detail above. However, the present invention is not limited to the above-described embodiment, and various modifications or changes can be made within the scope of the invention described in the claims. It goes without saying that they are also included in the scope of the present invention. For example, in the above-described embodiment, the present invention is applied to a floor-standing type reinforcing bar bender, but the present invention may be applied to a hydraulically operated portable reinforcing bar bender.

[0024]

According to the above construction of the present invention, the center axis of the bending roller is decentered outward in the bending radial direction with respect to the center axis of the moving shaft, so that the entire apparatus can be reduced in size and deformed. A rebar bender that achieves smooth bending of rebar can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a reinforcing bar bender according to the present invention.

FIG. 2 is a side view of the reinforcing bar bender shown in FIG.

FIG. 3 is a longitudinal sectional view of the reinforcing bar bender shown in FIG.

FIG. 4 is a partially enlarged sectional view of the reinforcing bar bender shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rebar bender 2 Casing 3 Electric motor 4 Operation part 5 Fixed roller 6 Guide 7 Top plate 8 Curved groove 9 Moving axis 10 Bending roller 91 Large diameter part 92, 93 Center axis

Claims (2)

(57) [Claims] 1. A fixed roller forming a bending center of a reinforcing bar to be processed, a bending roller pressing the reinforcing bar against the fixed roller, a moving shaft carrying the bending roller, and supporting the moving shaft. A rebar bender comprising: a rotating member that moves the moving shaft along a predetermined curved path; and a supporting member that bears a reaction force of a bending force applied to the rebar. A bending bender eccentric outward in a bending radial direction with respect to a center axis of the moving shaft. 2. The moving shaft has a shaft portion that penetrates a top plate forming a main casing of a reinforcing bar bender, and a radially expanding portion that expands in a radial direction above the top plate. The central axis of the portion is eccentric outward in the bending radial direction with respect to the central axis of the shaft portion, and the bending roller is disposed concentrically on the outer periphery of the enlarged diameter portion. 2. The reinforcing bar bender according to 1.