JP4634857B2 - Rebar bending method and apparatus - Google Patents

Description

  The present invention relates to a method for bending a reinforcing bar particularly useful when a reinforcing bar is bent to form, for example, a frame-shaped hoop bar, and an apparatus therefor.

  Hoop bars (strip bars) formed by bending reinforcing bars into squares, rectangles, etc. and joining both ends fix the position of the main bars by attaching them to the outer periphery of the main bars such as reinforced concrete columns. Resist the force and prevent buckling of the main muscle due to compressive force.

In order to make such a hoop bar, a pair of bending units formed by combining a fulcrum roll and a force point roll swiveling around the fulcrum roll are used to bend the two bending positions of the reinforcing bar simultaneously in the same direction. A bending apparatus for processing is known (for example, Patent Document 1). The pair of bending units can be moved back and forth on a common straight line to change the interval between the bending positions, and a clamper for clamping the reinforcing bars being bent is arranged in the middle of the bending positions. Has been. Therefore, this method can be used to bend a linear reinforcing bar into a quadrangular frame by changing the interval between the bending units and performing two right angle bending processes at two locations.
JP 2003-117612 A

  According to such a conventional technique, it is sufficient that the rebar before processing to be carried into the bending unit is a straight line, but if the rebar before processing is bent or twisted, both ends of the rebar bent into a square shape do not face each other correctly. There is a problem that even if both ends of such a reinforcing bar are forcibly aligned and joined, a correct planar hoop bar cannot be formed. This problem is particularly noticeable when the rebar before processing is supplied in the form of a roll and is unwound for use. This is because it is not easy to correct the unrolled reinforcing bar into a correct straight line even through the correction device.

  Therefore, in view of the problems of the prior art, the object of the present invention is to bend the rebar before processing into a correct plane even if the rebar is bent or twisted by elastically deforming it so that it is bent in the bending direction. An object of the present invention is to provide a method of bending a reinforcing bar and an apparatus therefor.

  The structure of the first invention according to this application for achieving the above object (referring to the invention according to claim 1, hereinafter the same) is applied to a bending unit when bending a reinforcing bar simultaneously in the same direction by a pair of bending units. The rebars before being processed are carried in as if they are stretched, and the rebars are elastically bent and deformed by applying a force in the bending direction at the middle point of the bending unit without clamping the reinforcing bars, and are arranged between the bending units. The main point is to operate the bending unit by clamping the reinforcing bars with a clamper.

  In addition, the reinforcing bar before processing may be bent and deformed twice or more, and the time interval between the first bending deformation and the second bending deformation may be set as a short time interval. The bending unit may be operated by changing the interval between the bending units by temporarily restoring and re-clamping and re-clamping the reinforcing bars.

  The configuration of the second invention (referring to the invention according to claim 4, the same applies hereinafter) comprises a pair of bending units and a clamper disposed between the bending units, and the bending units are opposed to each other on a straight line. The clamper is elastically bent and deformed in the bending direction without clamping the unprocessed rebar that is carried over to the bending unit and clamps the rebar. The gist is to clamp.

  According to the configuration of the first aspect of the invention, the reinforcing bars before being processed are elastically bent and deformed in the bending direction by applying a force in the bending direction, so that the bending is restricted in the bending direction and the twist is not twisted. Distributed to the left and right. Therefore, by clamping the rebar in such a state and restraining it and operating the bending unit to perform bending, the shape after bending can be correctly made flat. In the present invention, the bending unit may be a conventional type in which the power point roll pivots around the fulcrum roll, and by simultaneously operating a pair corresponding to each bending position, each bending position is simultaneously bent in the same direction. It shall be. The bending angle at each bending position is typically 90 °, but may be less than 90 ° or more than 90 °.

  If the rebar before processing is bent or deformed two or more times at short time intervals, the rebar before processing will elastically recover from the first bending deformation and reciprocate in vibration. It is deformed again and clamped. Therefore, the rebar before processing can bend the bending more correctly in the bending direction, can distribute the twist more evenly, and can have a more flat shape after bending. At this time, the initial bending deformation may be applied for a short time of 0.5 seconds or less, for example, so as to apply a shocking force to the rebar before processing. You may apply power. The time interval between the first curve deformation and the second curve deformation is, for example, a short time of 0.5 seconds or less in order to cause a new curve deformation during a reciprocating rotation by elastic recovery from the previous curve deformation. It is good to do. The same applies to the time interval of each time when the curved deformation is performed twice or more.

  After one bending process, if the interval between the bending units is changed to a small value and the bending unit is operated again, a linear reinforcing bar is formed into a rectangular frame by setting the bending angle to 90 ° each time. be able to. At this time, by interposing a temporary unclamped state immediately before the second bending process, the deviation in the bending direction of each time can be minimized. However, the unclamped rebar shall be stably supported at the same height as, for example, the swivel table that supports the power point roll of the bending unit, and the unclamped time is the shortest time required for changing the position of the rebar. For example, it is preferably set to about 0.5 to 1 second.

  According to the configuration of the second invention, the first invention can be easily implemented by advancing a clamper that clamps the reinforcing bar to elastically deform the reinforcing bar before processing in the bending direction. Note that the clamper can apply a force necessary for bending deformation to the reinforcing bar by advancing in the bending direction via an air cylinder, for example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The reinforcing bar bending apparatus includes a pair of bending units 10 and 10 and a clamper 20 (FIGS. 1 and 2).

  The bending units 10 and 10 are mounted on the upper surfaces of the carriages 31 and 31 that move back and forth opposite to each other on the guide rails 32 that are arranged in a straight line. The clamper 20 is disposed between the bending units 10 and 10 on the carriages 31 and 31.

  Each bending unit 10 includes a fulcrum roll 11 and a force point roll 12 that turns around the fulcrum roll 11 (FIG. 3). However, FIGS. 3A and 3B are enlarged views of main parts of FIGS. 1 and 2, respectively.

  A top plate 31a is attached to the front upper surface of each carriage 31, and a circular turntable 13 is mounted on the top plate 31a at the same height. The fulcrum roll 11 is erected at the center position of the swivel table 13 and can be projected and retracted on the upper surface of the swivel table 13 via a linear drive source such as an air cylinder and a solenoid (not shown) in the carriage 31 (FIG. 3). (B) arrow K1 direction). On the other hand, the power point roll 12 is rotatably mounted on a shaft 12 a standing on the turning table 13. The power point roll 12 can be turned around the fulcrum roll 11 by rotating the turning table 13 through a rotation drive source in the cart 31 (not shown) (in the direction of arrow K2 in FIG. 3A). ).

  A stopper 14 is screwed onto the top plate 31a so as to partially protrude on the turntable 13. Spacers 14 a and 14 a are detachably attached to the front end of the stopper 14 in order to adjust and set a distance d between the outer periphery of the fulcrum roll 11.

  The bending unit 10 retracts the power point roll 12 near the stopper 14 (FIG. 3A), carries the reinforcing bar S into the space d between the fulcrum roll 11 and the stopper 14, and causes the power point roll 12 to be supported. By revolving around 11, the reinforcing bar S can be bent (in the direction of arrow K3 in FIG. 3A). This is because the reinforcing bar S is driven so that the stopper 14 side is restrained by the stopper 14 from the fulcrum roll 11 while the opposite side is wound around the fulcrum roll 11 by the power point roll 12. The distance d can be adjusted to the outer diameter of the reinforcing bar S by attaching / detaching the spacers 14 a and 14 a to / from the stopper 14, and the bending angle of the reinforcing bar S can be arbitrarily set by the turning angle of the power point roll 12. . Further, the bending direction of the reinforcing bar S (the direction of the arrow K3 in FIG. 3A) is in a plane parallel to the turntable 13 and the top plate 31a.

  The carriages 31 and 31 on which the bending units 10 and 10 are mounted are arranged so as to face each other with the clamper 20 in between (FIGS. 1 and 2). Therefore, when the carriages 31 and 31 are moved back and forth, the distance between the bending units 10 and 10 on the carriages 31 and 31 can be arbitrarily changed and set (solid lines and two-dot chain lines in FIGS. 1 and 2). .

  The interval between the bending units 10 and 10 on the carriages 31 and 31 is appropriately set, and the reinforcing bars S are loaded so as to be passed over the bending units 10 and 10 (the chain line in FIG. 1). When the force point rolls 12 and 12 are turned simultaneously by operating (in the directions of arrows K3 and K3 in FIG. 1), both ends of the reinforcing bar S can be simultaneously bent in the same direction (two-dot chain line in the same figure). However, in FIG. 1, the turning directions of the power point rolls 12 and 12 of the left and right bending units 10 and 10 are counterclockwise and clockwise, respectively. Further, if the bending angle of the reinforcing bar S by each bending unit 10 is 90 °, and the bending position of the reinforcing bar S by the bending units 10 and 10 is appropriately changed, the bending process is executed twice (arrow K4 in FIG. (K4 direction, arrow K5, K5 direction) and the reinforcing bar S can be formed in a rectangular frame shape. It is assumed that the clamper 20 clamps the intermediate point of the bending position of the reinforcing bar S during the bending process of the reinforcing bar S.

  The clamper 20 is mounted on the stand 21 between the carriages 31 and 31 (FIG. 4). However, FIG. 4A is an enlarged view corresponding to the arrow X in FIG. 2, and FIG. 4B is a view corresponding to the arrow Y in FIG.

  A vertical support plate 22 is attached to the upper end of the stand 21, and an air cylinder 23 with guide rods 23 a and 23 a is attached to the support plate 22 in the horizontal direction. A base plate 24 is fixed to the tip of the rod of the air cylinder 23, and the base plate 24 can be moved back and forth by the air cylinder 23 together with the guide rods 23a and 23a of the air cylinder 23. An air cylinder 26 is mounted upward on the lower surface of the bracket 25 protruding from the front surface of the base plate 24, and a clamp piece 27 is attached to the rod 26 a of the air cylinder 26 protruding on the bracket 25. . A guide plate 28 is provided on the bracket 25 so as to protrude forward of the bracket 25, and guide pieces 28a, 28a are fixed on the guide plate 28 so as to sandwich the rod 26a. In addition, the front end upper surface of the guide plate 28 and the front end outer surfaces of the guide pieces 28a and 28a are formed obliquely.

  The air cylinder 26 is a so-called rotary clamp cylinder. Therefore, when the rod 26a is extended, the air cylinder 26 can raise the clamp piece 27 and be orthogonal to the guide plate 28 and the guide pieces 28a, 28a (solid line in FIG. 4). The piece 27 can be lowered between the guide pieces 28a and 28a while being rotated so as to face the guide plate 28 and the guide pieces 28a and 28a (two-dot chain line in the figure). Therefore, when the reinforcing bar S exists so as to cross the guide plate 28 at the tips of the guide pieces 28a, 28a, the clamper 20 can lower the clamp piece 27 and clamp the reinforcing bar S on the guide plate 28. Further, the clamper 20 can apply a force so as to push the reinforcing bar S forward by the tips of the guide pieces 28a, 28a by extending the air cylinder 23 and advancing the whole (a dashed line in the figure). However, the reinforcing bar S at this time may be clamped by the clamp piece 27 or may not be clamped.

  On the other hand, in FIGS. 1 and 2, the guide plate 28 of the clamper 20 is set to substantially the same height as the top plates 31 a and 31 a of the carriages 31 and 31 and the turning tables 13 and 13 of the bending units 10 and 10. In addition, the rebar S before being carried in such a manner that it is carried over the bending units 10 and 10 crosses the guide plate 28 at the tips of the guide pieces 28a and 28a when the air cylinder 23 is shortened and the clamper 20 is retracted. . Therefore, when the clamper 20 is advanced in this state, the clamper 20 applies a force to the reinforcing bar S in the bending direction at the intermediate point of the bending units 10 and 10 (in the direction of arrow K6 in FIG. 1), and elastically moves the reinforcing bar S. Can be curved and deformed (solid line in the figure).

  The operation of such a bending apparatus is as follows.

  First, the power point roll 12 of each bending unit 10 is retracted near the stopper 14, the bending units 10, 10 are set at appropriate intervals via the carriages 31, 31, and the clamper 20 is moved backward to bend the bending units 10, 10. The unprocessed rebar S having a predetermined length is carried in such a manner as shown in FIG. 1 (dashed line in FIG. 1, time t = to in FIG. 5, hereinafter simply indicated as (t = to)).

  Subsequently, the clamper 20 is moved forward and backward immediately (t = t0 to t1), the rebar S is clamped, the bending units 10 and 10 are operated, and the rebar S is bent (t = t1 to t2). , Direction of arrows K4 and K4 in FIG. 1). When the clamper 20 is advanced, a force is applied to the intermediate point of the bending position of the reinforcing bar S by the bending units 10 and 10 to elastically deform the reinforcing bar S in the bending direction, and the bending of the reinforcing bar S before processing is bent. 10, the twisting of the reinforcing bar S can be distributed to the left and right of the clamper 20. In addition, by shortening the time interval Ta between the forward and backward movement of the clamper 20 before clamping and the forward movement for clamping to a short time of about 0.5 seconds or less, the elastic deformation is restored from the initial curved deformation and the reciprocating rotation is in progress. The rebar S is bent and deformed again, and the bending of the rebar S and the distribution of the twist can be made more correct.

  However, the bending deformation of the rebar S before clamping by the advancement of the clamper 20 may be performed only once, may be performed twice as shown in FIG. 5, or may be performed twice or more repeated every short time interval Ta. .

  When one bending process by the bending units 10 and 10 is completed (t = t2), the clamper 20 is retracted and the force point roll 12 of each bending unit 10 is returned to the original retracted position (t = t2 to t3). The carriages 31 and 31 are moved closer to the clamper 20 to reduce the interval between the bending units 10 and 10 (t = t3 to t4), and the bending units 10 and 10 are made to correspond to the next bending position. Thereafter, the clamper 20 temporarily unclamps and re-clamps the reinforcing bar S for a short time Tb, and operates the bending units 10 and 10 to bend the reinforcing bar S again (t = t5 to t6, FIG. 1). Arrow K5, K5 direction).

  Subsequently, the force point rolls 12 and 12 of the bending units 10 and 10 are returned to the retracted position (t = t6 to t7), the clamp of the reinforcing bar S by the clamper 20 is released, and then a rectangular frame shape is formed by a discharge device (not shown). The bent reinforcing bar S is discharged (in the direction of arrow K7 in FIG. 1). Note that the discharging device grips both opposite ends of the frame-shaped reinforcing bar S and transports them to the next welding step to join both ends. Further, when discharging the reinforcing bar S, the fulcrum roll 11 of each bending unit 10 is temporarily stored in the carriage 31 lower than the turning table 13 and the top plate 31a, and the discharging of the reinforcing bar S is allowed. Thereafter, the bending units 10 and 10 are separated from each other via the carriages 31 and 31 (t = t8 to t9), and the next bending cycle of the reinforcing bar S is repeated.

  In order to elastically curve and deform the rebar S before being processed, the pressing force and forward stroke of the clamper 20 by the air cylinder 23 are the outer diameter of the rebar S 10 to 16 mm and the interval between the bending positions by the bending units 10 and 10. As 1300-3300 mm, they are on the order of about 60 kg and about 50 mm, respectively. However, the optimum value of the pressing force of the clamper 20 and the forward stroke may vary depending on the degree of bending or twisting that may occur in the rebar S before processing, the outer diameter and type of the rebar S, the interval between bending positions, and the like. It is preferable to set as appropriate according to experimental trials. Further, the position at which the pressing force is applied to the reinforcing bar S by the clamper 20 does not need to be a strict intermediate point between the bending positions by the bending units 10 and 10, and the bending and twisting of the reinforcing bar S before processing can be appropriately regulated. As much as possible, it should be set at approximately the midpoint.

  The present invention is particularly useful when a pair of bending units 10 and 10 are used to form a hoop line by performing two bendings in the same direction at a bending angle of 90 ° twice. In addition, the present invention can be applied to a case where only one portion is bent at an arbitrary bending angle. For example, in FIG. 1, when only one bending unit 10 is used to bend the reinforcing bar S in the illustrated direction or in the direction opposite to the illustrated direction, if the reinforcing bar S is bent and elastically deformed, the reinforcing bar S before processing is bent. However, the entire shape after bending can be made flat and can be properly stored in one plane. However, at this time, the bending unit 10 on the unused side may be a simple stopper when the reinforcing bar S is curved. Further, the force that elastically deforms the reinforcing bar S is expressed as a pressing force or a tensile force via an engaging member other than the clamper 20 that engages the reinforcing bar S, instead of the pressing force that is generated by moving the clamper 20 forward. May be added.

Overall configuration plan view Front view of overall configuration Explanatory diagram of essential part configuration (1) Explanatory diagram of main part expansion configuration (2) Operation explanation diagram

Explanation of symbols

S ... Reinforcing bar Ta ... Time interval 10 ... Bending unit 20 ... Clamper 31 ... Dolly

Patent applicant
Attorney Tadaaki Matsuda, Attorney

Claims (4)

When bending a reinforcing bar in the same direction at the same time with a pair of bending units, carry the reinforcing bar before processing as if it is passed over the bending unit, and force the bending direction at the middle point of the bending unit without clamping the reinforcing bar. In addition, a method for bending a reinforcing bar, wherein the reinforcing bar is elastically bent and deformed , the reinforcing bar is clamped by a clamper disposed between the bending units, and the bending unit is operated. The machining before rebar is curved and deformed more than once, bending method of reinforcing bars according to claim 1, characterized in that the short time interval between the first curved deformation and the second curved deformation.   After execution of the method of bending a reinforcing bar according to claim 1 or 2, the bending deformation is restored to change the interval between the bending units, the reinforcing bar is temporarily unclamped and re-clamped, and the bending unit is operated. Rebar bending method characterized by the above. The bending unit includes a pair of bending units and a clamper disposed between the bending units. The bending unit is mounted on a carriage that moves back and forth in a straight line opposite to each other, and the clamper is attached to the bending unit. over and passes way elastically curved deformed in a bending direction without clamping the carried-in unprocessed reinforcing bar Rutotomoni, clamping the reinforcing bars, reinforcing bar bending device, characterized in that the unclamping.

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