JPS60227928A - Bending method of reinforcing bar - Google Patents

Abstract

PURPOSE:To execute bending by which each side is not twisted in the plane by forming substantially and simultaneously two adjacent bend parts, when bending a reinforcing bar in two parts or more at intervals. CONSTITUTION:A bending metallic die 10 and a rotary roller 11 are placed in bend parts 2, 2 where a short side part 3 of a reinforcing bar 1 becomes a projecting state, the roller 11 is rotated simultaneously around the periphery of the metallic mold 10 in the directions as indicated with arrows A, B, and the short side part 3 is formed. Subsequently, the metallic die 10 of the right side is shifted to a bending position D, the roller 11 is rotated slightly in the direction as indicated with an arrow E, the bend part 2 is formed as pre-working for forming exactly a side part 4c, and subsequently, in the left side,too, the same operation is executed at a bending position C. Next, the metallic die 10 is fixed to the bending positions C and D, two rollers 11 are rotated simultaneously in the directions as indicated with arrows G, H, and the side parts 4b, 4c are bent simultaneously by a desired angle and formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention provides a method for bending reinforcing bars that reduces twisting when the reinforcing bars are bent at two or more locations spaced apart.

[Prior art]

Reinforcing bars for reinforcing concrete structures are often bent into various shapes such as ``J'', ``Δ'', etc.On the other hand, the surface of the reinforcing bars used for this purpose is made of concrete. Two or more ribs are formed on the surface to increase the bonding strength.

Normally, when bending reinforcing bars, multiple reinforcing bars are arranged and fed to a bending machine and bent at the same time to improve efficiency, but when reinforcing bars are fed to a bending machine at random, the direction of the ribs Because each side is not bent in the same plane, for example,
In the case of reinforcing bars that are bent in a ``kuji'' shape, the opposing sides are twisted laterally.

The cause of this "kink" is often due to the ribs formed on the surface of the reinforcing bars, and in order to prevent this defect by hammering, in the past, workers had to check each reinforcing bar one by one in the direction of the ribs. They are then fed to a bending machine for processing.

Due to these circumstances, currently no reinforcing bar processing machine capable of automatically supplying reinforcing bars has been developed.

More specifically, examples of the shapes of various types of reinforcing bars for concrete include those shown in FIGS. 1 to 3.

In Fig. 1, a reinforcing bar 1 is provided with two bent parts 2 to form a square shape. In Fig. 2, a reinforcing bar 1 is provided with bent portions 2 at three locations, and the short side portion 3 of each end is further bent into an L-shape to form a substantially U-shape as a whole. FIG. 3 shows a structure in which the short side portion 3 is bent into a V-shape, and the whole is formed into a substantially U-shape.

Now, when the reinforcing bars are bent in this way, as shown in FIG.
c are not parallel in the horizontal plane, and the end portion of the side portion 4C is “twisted” by a distance of δ with respect to the side piece portion 4b. That is, one side piece is floating relative to the other side piece.

It is very difficult to handle reinforcing bars whose side parts are twisted and bent as described above when bundling them or using them as aggregates for columns. 4c had to be manually corrected so that they were parallel, and the work was very complicated.

Therefore, the present inventors made various changes such as (changing the shape of the rotating roller of the Al reinforcing bar bending machine to one with a guide groove, (adding a bl twist prevention plate, and (C) modifying the reaction force receiver to increase its weight. I tried various methods, but none of them were able to prevent the twisting.

[Purpose and outline of the invention]

An object of the present invention is to provide a method for manufacturing a reinforcing bar in which each side is bent in a plane when two or more bent portions are formed at intervals in the reinforcing bar.

To achieve the above object, the present invention provides a method for bending a reinforcing bar in which side portions are formed on both sides of a central portion.
It is characterized in that both sides are bent substantially simultaneously when the side sides are bent with respect to the central side.

〔Example〕

Next, referring to the drawings, a method of processing a reinforcing bar having the shape shown in FIG. 2 (or FIG. 3) according to an embodiment of the present invention will be described.

(1st step) First, the reinforcing bar 1 is cut into a predetermined length.

(Second process) As shown in Fig. 5, the bending die (fixed roller) 10 and rotating roller 11 of the reinforcing bar bending machine are moved to a predetermined distance to fix the bending die 10, and then With the short side 3 protruding, the rotary roller 11 is simultaneously moved (rotated) around the bending mold 10 in the directions of arrows A and B, and the short side 3 is
form.

(Third step) As shown in FIG. 6, one (right side in this embodiment) of the bending die 10 is moved to the bending position iD, and the rotary roller 11 is moved around the bending die 10 in the direction of arrow E. By slightly rotating it, the bent portion 2 for forming the side portion 4C is formed slightly.

This step corresponds to pre-processing to accurately position the bent portion 2 and to accurately form the side portions 4b and 4c, and is determined experimentally depending on the type of reinforcing bar. .

(Fourth process) Next, as shown in FIG. By rotating it, the side portion 4b is slightly formed like the side portion 4c. The angle between the side portion 4b and the center side portion 4a is the same as that of the side portion 4C formed in the third step.

(Fifth step) The prototype of the reinforcing bar l shown in FIG. 2 was formed through the above steps, and two pieces were formed with the bending mold IO fixed at bending positions C and D as shown in FIG. Rotating rollers 11 are simultaneously rotated around the bending die 10 in the directions of arrows G and H to simultaneously bend and form the side portions 4b and 4c at a desired angle, thereby completing the reinforcing bar 1 shown in FIG.

〔Effect of the invention〕

The present invention is characterized in that when the side portions 4b and 4c are bent on both sides of the central side portion 4a as described above, the side portions 4b and 4c are bent substantially at the same time.

When forming the two bent portions 2 in this way, instead of bending one portion one by one, the two bent portions 2 are bent substantially simultaneously, and when looking at the side portions 4b and 4c from the side, Even with reinforcing bars that have protruding ribs on the surface,
They can be formed substantially parallel. (4th
(In the figure, the side part 4C can be bent to the position 4c'.) The present invention makes it possible to simultaneously bend a large number of reinforcing bars without causing a single twist, regardless of the presence or absence of ribs. According to the present invention, it is possible to manufacture a bending machine that can perform consistent operations of automatically supplying, automatically bending, and automatically discharging a large number of reinforcing bars.

As explained in the embodiments, the present invention can be effectively applied to the manufacture of reinforcing bars bent into a corner shape, but is not limited to this, and can be effectively applied to manufacturing reinforcing bars bent into a corner shape, a triangular shape, or other shapes. It can also be used for forming reinforcing bars.

[Brief explanation of the drawing]

FIGS. 1, 2, and 3 are front views of the reinforcing bars bent into an opening shape, and FIG. 4 is a perspective view showing the twisted state of the reinforcing bars shown in FIG. 1. FIG. 5, FIG. 6, FIG. 7, and FIG. 8 are explanatory diagrams of the order of the reinforcing bar bending method according to the present invention. 1...Reinforcement bar, 2...Bent part, 3...Short side part, 4a
...Central side part, 4b, 4c...Side side part, 10...
Bending mold, 11...rotating roller. Agent: Patent Attorney Shin Ogawa − Patent Attorney Ken Noguchi Teru Patent Attorney Kazuhiko Saishita

Claims (1)

[Claims] A method for bending reinforcing bars, characterized in that, when bending reinforcing bars at two or more locations at a certain interval, bends at two adjacent locations are formed substantially simultaneously.