A device for bending reinforcement bars
By using a step-by-step bending method and a limiting groove design, the problems of U-shaped springback and high energy consumption in bending small-radius anchor bars were solved, resulting in reduced equipment wear and improved dimensional accuracy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- LIAONING NORTH RUBBER & PLASTIC MASCH CO LTD
- Filing Date
- 2025-07-24
- Publication Date
- 2026-07-14
AI Technical Summary
Existing technologies suffer from U-shaped springback when bending small-radius anchor bars, resulting in high energy consumption and severe equipment wear, making it difficult to achieve the required precision.
The step-by-step bending method is adopted. First, the distance between the limit wheels is adjusted to be greater than the bending distance for preliminary bending. Then, it is tightened to the bending distance to complete the bending. Combined with the design of the reset component and the limit groove, the equipment load and energy consumption are reduced.
It reduces equipment wear and energy consumption, improves the dimensional accuracy of anchor bar production, and ensures the stability and precision of bending effect.
Smart Images
Figure CN224487493U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of bending technology, specifically to an anchor bar bending device. Background Technology
[0002] Bridge expansion joints: These are expansion joints that are typically installed between the ends of two beams, between the beam end and the abutment, or at the hinged joints of the bridge to accommodate bridge deck deformation.
[0003] Bridge expansion joints include anchor bars, which primarily serve to fix and connect components. By being fixed to the concrete structure, the anchor bars ensure the stability and durability of the expansion joint. The raw material for the anchor bars is twisted steel bars, which require bending during production.
[0004] Existing technologies generally employ a bending principle known as "three-point bending." The specific working method is as follows: the rebar to be bent is placed horizontally, with symmetrical sections on either side of the bending point supported by two fixed limiting points. Then, a hydraulic cylinder located directly above the center of the rebar drives a pressure head to move vertically downwards, applying pressure to the center of the rebar. Under the support and constraint of the two fixed points, the rebar undergoes plastic deformation at the point of pressure head application, forming a U-shaped bend.
[0005] Although this three-point bending method is relatively simple in structure and direct in control, and is widely used in most standard bending scenarios, it has a significant inherent drawback, especially when small radius bending is required:
[0006] U-shaped bend springback: Although bending the steel bar damages the material properties, there will still be a small range of springback after a U-shaped bend, which will make the opening of the U larger.
[0007] Small-radius bending consumes a lot of energy and puts a heavy burden on equipment: Bending with a very small fulcrum spacing L means that the effective bending deformation zone of the steel bar is short, and the stress concentration phenomenon of the material resisting deformation is more significant. At the same time, from the perspective of lever principle, the power arm (the horizontal distance from the fulcrum to the pressure point) for applying force by the pressure head is greatly shortened. These two factors together cause the hydraulic cylinder to output a huge downward force to overcome the yield strength of the material to complete the bending. This not only greatly increases energy consumption, but also places higher strength and rigidity requirements on key components such as the hydraulic system, pressure head structure, and frame, accelerates equipment wear, and may even lead to inaccurate bending angles or failure due to insufficient force. Utility Model Content
[0008] To address the aforementioned shortcomings of existing technologies, this utility model provides an anchor bar bending device. First, the distance between a pair of limiting wheels is adjusted to be greater than the bending distance. Then, the pressure head presses down on the center position of the rebar to a position that conforms to the bending radius for preliminary bending. Finally, the distance between the pair of limiting wheels is tightened to the bending distance to complete the bending. This step-by-step bending reduces wear and load on the equipment and reduces energy consumption.
[0009] To achieve the above objectives, this utility model provides the following technical solution: an anchor bar bending device, comprising a vertical plate, a pair of synchronously operating first hydraulic cylinders, a pair of limiting wheels, a second hydraulic cylinder, a pressure head, and a reset assembly. The pair of first hydraulic cylinders are fixedly mounted on the side wall of the vertical plate and are symmetrically designed. The telescopic ends of the first hydraulic cylinders face inward and are fixedly connected to a first mounting base. The pair of limiting wheels are rotatably mounted on the first mounting base. A first sliding groove is horizontally formed on the side wall of the vertical plate corresponding to the position of the first mounting base. A first sliding block is fixedly mounted on the first mounting base corresponding to the position of the first sliding groove. The first sliding block and the first sliding groove... The system features a sliding connection between the two hydraulic cylinders. The second hydraulic cylinder is fixedly mounted on the side wall of the upright plate and vertically positioned on the symmetrical line of a pair of first hydraulic cylinders. The telescopic end of the second hydraulic cylinder faces downward and is fixedly connected to a second mounting base. The pressure head is mounted on the second mounting base. A second sliding groove is vertically formed on the side wall of the upright plate corresponding to the position of the second mounting base. A second slider is fixedly mounted on the second mounting base corresponding to the position of the second sliding groove. The second slider is slidably connected to the second sliding groove. The reset assembly is mounted on the side wall of the upright plate and positioned on the symmetrical line of a pair of first hydraulic cylinders. The reset assembly can prevent axial movement of the material and push out the bent material.
[0010] Preferably, the reset assembly includes a support plate, a pair of limiting rods, a fixing plate, and a pair of compression springs. The fixing plate is fixedly mounted on the side wall of the upright plate. A pair of limiting holes are vertically opened on the fixing plate, and a pair of limiting rods vertically move through the limiting holes. The support plate is fixedly mounted on the upper end of the pair of limiting rods. A pair of compression springs are sleeved on the limiting rods and located between the support plate and the fixing plate. In the absence of external force, the upper surface of the support plate is flush with the top of the pair of limiting wheels.
[0011] Preferably, the support plate has a first limiting groove horizontally.
[0012] Preferably, a threaded hole is provided at the center of the fixing plate, a threaded rod is screwed into the threaded hole, and a contact sensor is provided at the center of the bottom of the support plate.
[0013] Preferably, the limiting wheel is provided with a third limiting groove, and the bottom of the pressure head is provided with a second limiting groove.
[0014] Preferably, the pressure head is detachably connected to the second mounting base by bolts.
[0015] This utility model provides an anchor bar bending device, which has the following beneficial effects:
[0016] 1. This utility model first adjusts the distance between a pair of limiting wheels to be greater than the bending distance, then presses the center position of the steel bar down to a position that meets the bending radius through the pressure head to perform preliminary bending, and finally tightens the distance between the pair of limiting wheels to the bending distance to complete the bending. Step-by-step bending reduces wear and load on the equipment and reduces energy consumption.
[0017] 2. In this invention, the steel bar is first bent at a distance greater than the bending spacing, and then bent at the normal bending radius. The two ends of the steel bar will move inward. However, when the bent steel bar is removed, there will be a small amount of springback. The inward movement of the two ends of the steel bar can just compensate for the springback, thereby improving the accuracy of the anchor bar production dimensions. Attached Figure Description
[0018] Figure 1 This is a front view of an anchor bar bending device according to the present invention;
[0019] Figure 2 This is a schematic diagram of the anchor bar bending device of this utility model when the pressure head is pressed down;
[0020] Figure 3 This is a schematic diagram of the anchor bar bending device of this utility model after the limiting wheel is tightened.
[0021] In the diagram: 1. Vertical plate; 2. First hydraulic cylinder; 3. First mounting base; 4. Limiting wheel; 5. First slider; 6. First slide groove; 7. Second hydraulic cylinder; 8. Second mounting base; 9. Pressure head; 10. Bolt; 11. Second slider; 12. Second slide groove; 13. Support plate; 14. Limiting rod; 15. Compression spring; 16. Fixing plate; 17. Threaded rod; 18. Threaded hole; 19. Limiting hole; 20. First limiting groove; 21. Second limiting groove; 22. Third limiting groove; 23. Contact sensor. Detailed Implementation
[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0023] like Figure 1-3As shown, an anchor bar bending device includes a vertical plate 1, a pair of synchronously operating first hydraulic cylinders 2, a pair of limiting wheels 4, a second hydraulic cylinder 7, a pressure head 9, and a reset assembly. The pair of first hydraulic cylinders 2 are fixedly mounted on the side wall of the vertical plate 1 and are symmetrically designed. The telescopic ends of the first hydraulic cylinders 2 face inward and are fixedly connected to a first mounting base 3. The pair of limiting wheels 4 are respectively rotatably mounted on the first mounting base 3. A first sliding groove 6 is horizontally opened on the side wall of the vertical plate 1 corresponding to the position of the first mounting base 3. A first slider 5 is fixedly mounted on the first mounting base 3 corresponding to the position of the first sliding groove 6. The first slider 5 is slidably connected to the first slide groove 6. The second hydraulic cylinder 7 is fixedly mounted on the side wall of the upright plate 1 and vertically located on the symmetrical line of a pair of first hydraulic cylinders 2. The telescopic end of the second hydraulic cylinder 7 faces downward and is fixedly connected to a second mounting base 8. The pressure head 9 is mounted on the second mounting base 8. A second slide groove 12 is vertically formed on the side wall of the upright plate 1 corresponding to the position of the second mounting base 8. A second slider 11 is fixedly mounted on the second mounting base 8 corresponding to the position of the second slide groove 12. The second slider 11 is slidably connected to the second slide groove 12. The reset assembly is provided. On the side wall of the upright plate 1 and located on the symmetrical line of a pair of first hydraulic cylinders 2, the reset assembly can prevent axial movement of materials and push out bent materials; the reset assembly includes a support plate 13, a pair of limiting rods 14, a fixing plate 16, and a pair of compression springs 15. The fixing plate 16 is fixedly installed on the side wall of the upright plate 1, and a pair of limiting holes 19 are vertically opened on the fixing plate 16. The pair of limiting rods 14 vertically move through the limiting holes 19. The support plate 13 is fixedly installed on the upper end of the pair of limiting rods 14, and the pair of compression springs 15 are sleeved on the limiting rods 14 and... Located between the support plate 13 and the fixed plate 16, the upper surface of the support plate 13 is flush with the top of a pair of limiting wheels 4 when there is no external force; the support plate 13 has a first limiting groove 20 horizontally; the fixed plate 16 has a threaded hole 18 at its center, and a threaded rod 17 is screwed into the threaded hole 18; a contact sensor 23 is provided at the center of the bottom of the support plate 13; a third limiting groove 22 is provided on the limiting wheel 4; a second limiting groove 21 is provided at the bottom of the pressure head 9; the pressure head 9 is detachably connected to the second mounting base 8 by bolts 10.
[0024] Its detailed connection methods are well-known technologies in this field. The following mainly introduces the working principle and process, as follows:
[0025] According to the instruction manual Figure 1-3As can be seen, when this utility model is in operation, the operator starts a pair of synchronously working first hydraulic cylinders 2 to adjust the distance between a pair of limit wheels 4. The distance can be adjusted to be greater than the bending distance. Then, the operator places the steel bar to be bent horizontally on the pair of limit wheels 4, with the two sides of the steel bar symmetrical. At this time, the operator starts the second hydraulic cylinder 7 to press the pressure block down on the center of the steel bar until it meets the bending radius, that is, the distance from the bottom of the pressure head 9 to the center line of the pair of limit wheels 4 is equal to the bending radius. Of course, it can also be slightly greater than the bending radius. This process is the initial bending. Finally, the pair of first hydraulic cylinders 2 work again to drive the pair of limit wheels 4 to tighten, so that the distance is the bending distance (twice the bending radius). During the tightening process, the two sides of the steel bar will continue to bend until the final bending state is reached. The second cylinder drives the pressure head 9 to retract, and the bent steel bar, i.e., the anchor bar, can be taken out. In this process, small errors are allowed in the placement of the reinforcing bars, the adjustment of the spacing of the limiting wheels 4, and the synchronous operation of the first hydraulic cylinder 2. The specific error depends on the length of the bent reinforcing bar and the bending radius. Those skilled in the art can judge based on their work experience and the allowable error of the anchor bars. Generally, the final error is within 2cm, ensuring that the finished product can be welded to the crossbeam of the bridge expansion joint. In this utility model, the bending spacing during the initial bending is greater than the normal bending spacing. Therefore, the force during bending is reduced, the wear and load on the equipment is reduced, and energy consumption is reduced. In addition, by first performing a bending greater than the bending spacing and then performing a bending with the normal bending radius, the two ends of the reinforcing bar will show an inward movement. When the bent reinforcing bar is removed, a small amount of springback will occur. The inward movement of the two ends of the reinforcing bar just compensates for the springback, thereby improving the accuracy of the anchor bar production dimensions. The problem of bending (inward movement) is cleverly used to solve another problem (springback).
[0026] The reset assembly includes a support plate 13, a pair of limiting rods 14, a fixing plate 16, and a pair of compression springs 15. The fixing plate 16 is fixedly mounted on the side wall of the upright plate 1, and a pair of limiting holes 19 are vertically opened on the fixing plate 16. The pair of limiting rods 14 vertically move through the limiting holes 19. The support plate 13 is fixedly mounted on the upper end of the pair of limiting rods 14. The pair of compression springs 15 are sleeved on the limiting rods 14 and located between the support plate 13 and the fixing plate 16. In the absence of external force, the upper surface of the support plate 13 is flush with the top of the pair of limiting wheels 4. During operation, the reinforcing bar can be placed on the pair of limiting wheels 4 and the support plate 13. The support plate 13 and the pressure head 9 press against each other to prevent the reinforcing bar from moving axially. After bending, the pressure head 9 retracts, and the reaction force of the compression springs 15 can push the reinforcing bar upward, making it easy for personnel to remove the bent reinforcing bar.
[0027] The support plate 13 has a first limiting groove 20 horizontally, the limiting wheel 4 has a third limiting groove 22, and the bottom of the pressure head 9 has a second limiting groove 21, which is used to limit the steel bar and improve its stability. The size of the limiting groove is designed as common knowledge to those skilled in the art, and the radius is generally equal to or greater than the radius of the steel bar.
[0028] The fixed plate 16 has a threaded hole 18 at its center, and a threaded rod 17 is screwed into the threaded hole 18. A contact sensor 23 is provided at the center of the bottom of the support plate 13. The threaded rod 17 can rotate to adjust the distance from the bottom of the support plate 13. In conjunction with the contact sensor 23, the downward pressing distance of the pressure head 9 can be detected, thereby controlling the operation of the second hydraulic cylinder 7. This is something that those skilled in the art can understand.
[0029] The pressure head 9 is detachably connected to the second mounting base 8 via bolts 10, allowing the pressure head 9 to be replaced according to different bending radii.
[0030] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. An anchor bar bending device, characterized in that, The assembly includes a vertical plate (1), a pair of synchronously operating first hydraulic cylinders (2), a pair of limit wheels (4), a second hydraulic cylinder (7), a pressure head (9), and a reset assembly. The pair of first hydraulic cylinders (2) are fixedly mounted on the side wall of the vertical plate (1) and are designed symmetrically on both sides. The telescopic ends of the first hydraulic cylinders (2) face inward and are fixedly connected to a first mounting base (3). The pair of limit wheels (4) are respectively rotatably mounted on the first mounting base (3). The side wall of the vertical plate (1) is horizontally provided with a first sliding groove (6) corresponding to the position of the first mounting base (3). The first mounting base (3) is fixedly provided with a first slider (5) corresponding to the position of the first sliding groove (6). The first slider (5) is slidably connected to the first sliding groove (6). The second hydraulic cylinder (7) is fixedly mounted on the side wall of the vertical plate (1). The second hydraulic cylinder (7) is fixedly installed on the side wall of the upright plate (1) and vertically located on the symmetrical line of a pair of first hydraulic cylinders (2). The telescopic end of the second hydraulic cylinder (7) faces downward and is fixedly connected to the second mounting seat (8). The pressure head (9) is set on the second mounting seat (8). The side wall of the upright plate (1) is vertically provided with a second sliding groove (12) corresponding to the position of the second mounting seat (8). The second mounting seat (8) is fixedly provided with a second slider (11) corresponding to the position of the second sliding groove (12). The second slider (11) is slidably connected to the second sliding groove (12). The reset assembly is set on the side wall of the upright plate (1) and located on the symmetrical line of a pair of first hydraulic cylinders (2). The reset assembly can prevent the material from moving axially and push out the bent material.
2. The anchor bar bending device according to claim 1, characterized in that, The reset assembly includes a support plate (13), a pair of limiting rods (14), a fixing plate (16), and a pair of compression springs (15). The fixing plate (16) is fixedly installed on the side wall of the upright plate (1). A pair of limiting holes (19) are vertically opened on the fixing plate (16). A pair of limiting rods (14) vertically move through the limiting holes (19). The support plate (13) is fixedly installed on the upper end of the pair of limiting rods (14). A pair of compression springs (15) are sleeved on the limiting rods (14) and located between the support plate (13) and the fixing plate (16). In the absence of external force, the upper surface of the support plate (13) is flush with the top of the pair of limiting wheels (4).
3. The anchor bar bending device according to claim 2, characterized in that, The support plate (13) has a first limiting groove (20) horizontally.
4. The anchor bar bending device according to claim 2, characterized in that, The fixed plate (16) has a threaded hole (18) at its center, and a threaded rod (17) is screwed into the threaded hole (18). A contact sensor (23) is provided at the center of the bottom of the support plate (13).
5. The anchor bar bending device according to claim 1, characterized in that, The limiting wheel (4) is provided with a third limiting groove (22), and the bottom of the pressure head (9) is provided with a second limiting groove (21).
6. The anchor bar bending device according to claim 1, characterized in that, The pressure head (9) is detachably connected to the second mounting base (8) by bolts (10).