Reinforcing steel positioning and bending device for house building projects

Abstract

The utility model relates to the field of building engineering construction equipment discloses a steel bar positioning and bending device for house building engineering, including the shell, the inner wall right side of shell is connected with the square one of sliding, the inner wall left side of shell is connected with the square two of sliding, the outer wall left side of square one is fixedly connected with the transmission gear strip of front part, the right side of square one's outer wall is equipped with the square groove, the outer wall right side of square two is fixedly connected with the transmission gear strip of back part, the right side of square two's outer wall is equipped with the square groove, the adjacent side of transmission gear strip is engaged with gear no.

Description

Technical Field

[0001] This utility model relates to the field of construction equipment for building engineering, and in particular to a rebar positioning and bending device for building construction. Background Technology

[0002] In building construction, a rebar positioning and bending device is an important piece of construction equipment. It is mainly used for precise positioning and bending of rebar at specific angles to meet the shape requirements of rebar in different parts of the building structure. This rebar positioning and bending device can bend straight rebar into various shapes according to design requirements to adapt to the rebar arrangement of different building components such as beams, columns, and slabs. Its precise positioning function ensures that the positional deviation of the rebar is minimal during the bending process, which greatly improves construction efficiency, reduces rework caused by inaccurate rebar positioning, and effectively shortens the construction period of building projects.

[0003] Early rebar positioning and bending devices mainly consisted of a mechanical positioning structure, a manual bending mechanism, and a basic frame. During operation, workers manually placed the rebar on the positioning structure and manually controlled the bending mechanism to bend the rebar using the lever principle. Because the positioning structure was just a simple slot and clamp, it was difficult to adapt to various specifications of rebar, resulting in inaccurate positioning, large deviations in bending angle and position, and limited power of the bending mechanism. When dealing with high-strength rebar, not only was the bending efficiency low, but the equipment was also prone to damage. Existing rebar positioning and bending devices are driven by hydraulic and servo motors, which provide stronger power and more precise control, improving bending efficiency and quality.

[0004] However, there are still cases where manual loading and unloading of rebar positioning and bending devices are required. This not only exposes workers to the operating area of ​​the equipment, posing safety hazards, but also makes it difficult to maintain complete consistency in the placement and force of the rebars during manual operation, resulting in insufficient accuracy in loading and unloading. Utility Model Content

[0005] To overcome the above shortcomings, this utility model provides a steel bar positioning and bending device for building construction, which aims to solve the problems of inaccurate manual bending and personal safety hazards during the bending process in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A rebar positioning and bending device for building construction includes a housing. A first block is slidably connected to the right side of the inner wall of the housing, and a second block is slidably connected to the left side of the inner wall of the housing. A transmission gear rack is fixedly connected to the front left side of the outer wall of the first block, and a square groove is formed on the right side of the outer wall of the first block. A transmission gear rack is fixedly connected to the rear right side of the outer wall of the second block, and a square groove is formed on the right side of the second block. A servo motor is fixedly connected to the top of the inner wall of the housing, and a second gear is fixedly connected to the output end of the servo motor. The front and rear sides of the outer wall of the second gear... All are meshed with the two transmission gear racks. An arc-shaped slotted plate is fixedly connected to the front bottom of the inner wall of both blocks. A semi-circular block is fixedly connected to the rear bottom of the inner wall of both blocks. A servo motor is fixedly connected to the bottom of both blocks. A bending device is fixedly connected to the output end of the servo motor. A hydraulic telescopic rod is fixedly connected to the middle of the front side of the inner wall of the outer shell. A right-angle pressure block is fixedly connected to one end of the hydraulic telescopic rod. A pushing mechanism is provided on the left side of the outer shell. The pushing mechanism is used to push the reinforcing bar.

[0008] As a further description of the above technical solution:

[0009] The pushing mechanism includes a horizontal plate, which is fixedly connected to the middle left side of the inner wall of the outer shell. A second limiting plate is fixedly connected to the top front side of the horizontal plate. A grooved gear rack is fixedly connected to the middle top side of the horizontal plate. A C-shaped frame is slidably connected to the rear side of the grooved gear rack. A push plate is fixedly connected to the right side of the C-shaped frame. A first servo motor is fixedly connected to the left side of the C-shaped frame. A first gear is fixedly connected to the output end of the first servo motor. The outer wall of the first gear meshes with the grooved gear rack. A first limiting plate is slidably connected to the left side of the outer shell. A threaded rod with a handle is rotatably connected to the right side of the first limiting plate. The outer wall of the threaded rod with a handle is threadedly connected to the outer shell.

[0010] As a further description of the above technical solution:

[0011] An observation window is provided on the front side of the outer casing, and a lighting lamp is fixedly connected to the top side of the front part of the inner wall of the outer casing.

[0012] As a further description of the above technical solution:

[0013] An alarm light is fixedly connected to the rear side of the housing, and an alarm sounder is fixedly connected to the left side of the alarm light.

[0014] As a further description of the above technical solution:

[0015] A discharge drawer is slidably connected to the bottom of the inner wall of the outer casing, and a guide rod is fixedly connected to the top of the discharge drawer.

[0016] As a further description of the above technical solution:

[0017] The bottom front and rear sides of the shell are fixedly connected to the legs, and the bottom of the legs is fixedly connected to the shock-absorbing pads.

[0018] As a further description of the above technical solution:

[0019] A protective box is fixedly connected to the top rear side of the horizontal plate, and an emergency brake button is fixedly connected to the bottom front side of the inner wall of the protective box.

[0020] As a further description of the above technical solution:

[0021] A length controller is rotatably connected to the middle of the bottom side of the inner wall of the protective box, and a curvature controller is rotatably connected to the right side of the bottom of the inner wall of the protective box.

[0022] This utility model has the following beneficial effects:

[0023] 1. In this utility model, the reinforcing bar is placed between the arc-shaped slotted plate and the semi-circular block. The hydraulic telescopic rod pushes the right-angle pressure block to press the middle of the reinforcing bar tightly. The servo motor two drives the bending device to bend the reinforcing bar. After completion, it is reset. Then, the servo motor three makes the gear two rotate, which drives the transmission gear rack to bring the first block and the second block closer together. After reaching the bending point, a second bend is performed. Finally, the hydraulic telescopic rod controls the third bend and the falling of the reinforcing bar. This reduces manual operation during bending, thereby reducing safety hazards and controlling the bending angle and side length.

[0024] 2. In this utility model, before the device is operated, the threaded rod with handle is rotated to move the limiting plate one left and right to adapt to the length of the reinforcing bar. Then, the reinforcing bar is placed in the U-shaped guide rail composed of the horizontal plate, the limiting plate two, and the grooved gear rack. Subsequently, the servo motor one drives the gear one to rotate. Under the action of the grooved gear rack, the C-shaped frame pushes the push plate to the right, causing the reinforcing bar to move to the left side of the limiting plate one and clamp the reinforcing bar with the limiting plate one. After the middle part of the reinforcing bar is clamped by the right-angle pressure block and the arc-shaped slotted plate, the push plate releases the left side of the reinforcing bar, realizing the pushing of the reinforcing bar. Attached Figure Description

[0025] Figure 1 This is a perspective view of a steel bar positioning and bending device for building construction proposed in this utility model.

[0026] Figure 2 This is a rear view of a steel bar positioning and bending device for building construction proposed in this utility model;

[0027] Figure 3 This is a side view of a steel bar positioning and bending device for building construction proposed in this utility model;

[0028] Figure 4This utility model provides a structural schematic diagram of a bending device for positioning and bending steel bars in building construction.

[0029] Figure 5 This is a schematic diagram of the grooved gear rack mechanism of a steel bar positioning and bending device for building construction proposed in this utility model.

[0030] Legend:

[0031] 1. Outer shell; 2. Pushing mechanism; 201. Horizontal plate; 202. Grooved gear rack; 203. C-shaped frame; 204. Push plate; 205. Gear 1; 206. Servo motor 1; 207. Limiting plate 1; 208. Limiting plate 2; 209. Threaded rod with handle; 3. Block 1; 4. Block 2; 5. Transmission gear rack; 6. Square slot; 7. Gear 2; 8. Arc-shaped slotted plate; 9. Semicircular block; 10. Servo motor 2; 11. Bending device; 12. Right-angle pressure block; 13. Hydraulic telescopic rod; 14. Observation window; 15. Lighting lamp; 16. Alarm light; 17. Alarm sounder; 18. Discharge drawer; 19. Guide rod; 20. Leg; 21. Shock-absorbing pad; 22. Bending controller; 23. Length controller; 24. Emergency brake button; 25. Protective box; 26. Servo motor 3. Detailed Implementation

[0032] 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.

[0033] Reference Figure 1 , Figure 3 and Figure 4This utility model provides an embodiment of a rebar positioning and bending device for building construction, comprising a housing 1, which is the load-bearing structure of the device. The inner wall of the housing 1 has grooves on its front and rear sides to facilitate the sliding of blocks 3 and 4. A horizontal strip is fixed to the middle of the right side of the inner wall of the housing 1. Block 3 is slidably connected to the right side of the inner wall of the housing 1, and block 4 is slidably connected to the left side of the inner wall of the housing 1. Two C-shaped fixing brackets are fixed to both sides of blocks 3 and 4 to facilitate the fixing of the arc-shaped grooved plate 8 and the semi-circular block 9. A transmission gear rack 5 is fixedly connected to the left side of the front part of the wall. The transmission gear rack 5 drives the corresponding fixed blocks 1 3 and 2 4 to move. A square groove 6 is opened on the right side of the outer wall of block 1 3 to facilitate the sliding of the transmission gear rack 5. A transmission gear rack 5 is fixedly connected to the right side of the rear part of the outer wall of block 2 4. A square groove 6 is opened on the right side of the outer wall of block 2 4. A servo motor 3 26 is fixedly connected to the top of the inner wall of the outer shell 1. The servo motor 3 26 is used to output kinetic energy to drive the rotation of gear 2 7. The output end of the servo motor 3 26 is fixedly connected to gear 2 7. 7. The outer wall of the second gear 7 meshes with the two transmission gear racks 5 on both the front and rear sides. Rotation of the second gear 7 causes the transmission gear racks 5 on both sides to move the corresponding fixedly connected blocks 3 and 4 closer and further apart. An arc-shaped slotted plate 8 is fixedly connected to the front bottom of the inner wall of blocks 3 and 4. A right-angled V-shaped groove is formed on the rear side of the arc-shaped slotted plate 8. A semi-circular block 9 is fixedly connected to the rear bottom of the inner wall of both blocks 3 and 4. The semi-circular block 9 is used to guide the bending of the reinforcing bars. A servo motor is fixedly connected to the bottom of both blocks 3 and 4. The second machine 10, the second servo motor 10 is used to drive the bending machine 11 to rotate, the output end of the second servo motor 10 is fixedly connected to the bending machine 11, the bending machine 11 bends the steel bar under the action of the second servo motor 10, the middle of the front side of the inner wall of the outer shell 1 is fixedly connected to the hydraulic telescopic rod 13, the hydraulic telescopic rod 13 pushes the right angle pressure block 12 to bend the steel bar, one end of the hydraulic telescopic rod 13 is fixedly connected to the right angle pressure block 12, the rear side of the right angle pressure block 12 is smooth, the left side of the outer shell 1 is provided with the pushing mechanism 2, the pushing mechanism 2 is used to push the steel bar;

[0034] Specifically, the reinforcing bar enters the guide track formed by the arc-shaped slotted plate 8 and the semi-circular block 9. At this time, the right-angle pressure block 12 is pressed tightly against the middle of the reinforcing bar by the hydraulic telescopic rod 13. At this time, the two servo motors 10 rotate simultaneously, causing the bending device 11 to bend the reinforcing bar. After bending, the bending device 11 returns to its original position. At this time, the servo motor 26 rotates and the gear 7 rotates, causing the blocks 3 and 4 to move closer to each other under the drive of the transmission gear rack 5. After reaching the second bending point, the servo motor 10 rotates again to drive the bending device 11 to bend the reinforcing bar a second time. After bending, the bending device 11 returns to its original position. At this time, the hydraulic telescopic rod 13 retracts, causing the reinforcing bar to slowly descend to the bottom of the arc-shaped slotted plate 8. When the hydraulic telescopic rod 13 expands again, the right-angle pressure block 12 bends the reinforcing bar a third time. Finally, the hydraulic telescopic rod 13 retracts, causing the reinforcing bar to fall downwards. This reduces manual operation when bending the reinforcing bar, thereby achieving precise control of the bending angle and side length and reducing safety hazards.

[0035] Reference Figure 1 , Figure 2 and Figure 5 The pushing mechanism 2 includes a horizontal plate 201, which is fixedly connected to the middle left side of the inner wall of the outer casing 1. A second limiting plate 208 is fixedly connected to the top front side of the horizontal plate 201. The second limiting plate 208 is used to limit the movement of the reinforcing bars, so that the reinforcing bars are vertically arranged on the guide rail between the second limiting plate 208 and the grooved gear rack 202. A grooved gear rack 202 is fixedly connected to the middle top side of the horizontal plate 201. The rear side of the grooved gear rack 202 is slotted to facilitate the sliding of the C-shaped frame 203. The front side meshes with a gear 1 205. The gear 1 205 rotates under the drive of a servo motor 1 206. Under the action of the grooved gear rack 202, the servo motor 1 206 and the C-shaped frame 203 move left and right. The rear side of the grooved gear rack 202 is slidably connected to the C-shaped frame 203. Servo motor 206 and push plate 204 form a C-shaped mechanism that slides on slotted gear rack 202. Push plate 204 is fixedly connected to the right side of C-shaped frame 203 and is used to push the reinforcing bar. Servo motor 206 is fixedly connected to the left side of C-shaped frame 203 and provides power for gear 205 to rotate. Gear 205 is fixedly connected to the output end of servo motor 206. Limiting plate 207 is slidably connected to the left side of housing 1. Push plate 204 pushes the reinforcing bar until it is limited by limiting plate 207. A threaded rod with handle 209 is rotatably connected to the right side of limiting plate 207. The outer wall of threaded rod with handle 209 is threadedly connected to housing 1. Rotation of threaded rod with handle 209 drives limiting plate 207 to move left and right.

[0036] Specifically, before the device is operated, the threaded rod 209 with a handle is rotated to move the limiting plate 207 left and right to adjust the length of the reinforcing bar. The reinforcing bar is placed in the U-shaped guide rail composed of the horizontal plate 201, the limiting plate 208, and the grooved gear rack 202. The servo motor 206 drives the gear 205 to rotate. Under the action of the gear rack on the grooved gear rack 202, the gear 205 causes the C-shaped frame 203 to move to the right. At the same time as the C-shaped frame 203 moves, it pushes the push plate 204. The push plate 204 pushes the reinforcing bar to the right until one end of the reinforcing bar moves to the left side of the limiting plate 207. The push plate 204 and the limiting plate 207 clamp the two sides of the reinforcing bar until the middle of the reinforcing bar is clamped by the right-angle pressure block 12 and the arc-shaped slotted plate 8. At this time, the push plate 204 releases the left side of the reinforcing bar, thereby achieving the pushing of the reinforcing bar.

[0037] Reference Figure 1 , Figure 2 and Figure 3 An observation window 14 is provided on the front side of the outer casing 1, which facilitates observation of the operation of the device. A lighting lamp 15 is fixedly connected to the top front part of the inner wall of the outer casing 1. The lighting lamp 15 is used for internal lighting of the device. An alarm lamp 16 is fixedly connected to the rear side of the outer casing 1. The alarm lamp 16 emits a light signal to warn of problems with the device. An alarm sounder 17 is fixedly connected to the left side of the alarm lamp 16. The alarm sounder 17 is used to emit an audible signal when an alarm occurs. A discharge drawer 18 is slidably connected to the bottom of the inner wall of the outer casing 1. The discharge drawer 18 is used to transport the processed steel bars. A guide rod 19 is fixedly connected to the top of the discharge drawer 18. The guide rod 19 is located at the bottom of the V-shaped groove on the arc-shaped slotted plate 8 and is used to guide the steel bars to fall.

[0038] Specifically, the observation window 14 facilitates observation of the device's operation, the lighting lamp 15 illuminates the outer casing 1 in dim light, the alarm lamp 16 emits a light signal when the device malfunctions, the alarm sounder 17 emits an audible signal, and the discharge drawer 18 slides to position the guide rod 19 at the bottom of the V-shaped groove of the arc-shaped slotted plate 8, thereby causing the reinforcing bar to fall along the guide rod 19.

[0039] Reference Figure 1 , Figure 2 and Figure 3The bottom front and rear sides of the outer shell 1 are fixedly connected to the legs 20. The legs 20 are used to raise the outer shell 1 so that the outer shell 1 does not contact the ground. The bottom of the legs 20 is fixedly connected to the shock-absorbing pads 21 to reduce the shaking of the device. The top rear side of the horizontal plate 201 is fixedly connected to the protective box 25. The protective box 25 protects the switch of the device to prevent accidental activation. The bottom front side of the inner wall of the protective box 25 is fixedly connected to the emergency brake button 24. The emergency brake button 24 is used to stop the device in case of failure. The middle of the bottom side of the inner wall of the protective box 25 is rotatably connected to the length controller 23. The length controller 23 controls the rotation of the servo motor 3 26 to make the blocks 1 3 and 2 4 move closer and further apart, thereby controlling the length of each bend. The bottom right side of the inner wall of the protective box 25 is rotatably connected to the bending controller 22. The bending controller 22 controls the rotation amplitude of the servo motor 2 10, thereby controlling the rotation angle of the bending device 11 to control the bending angle of the steel bar.

[0040] Specifically, the stand 20 raises the outer shell 1 to prevent corrosion when the ground is wet; the shock-absorbing pad 21 reduces the shaking of the device; the protective box 25 protects the device switch to prevent accidental activation; the emergency brake button 24 stops the device immediately in case of malfunction; the length controller 23 controls the rotation of the servo motor 26 to move the blocks 3 and 4 closer and further apart, thereby controlling the length of each bend of the steel bar; the bending controller 22 controls the rotation amplitude of the servo motor 10, thereby controlling the rotation angle of the bender 11 and thus controlling the bending angle of the steel bar.

[0041] Working principle: Before using the device, the steel bar first enters the guide track formed by the arc-shaped slotted plate 8 and the semi-circular block 9. At this time, the hydraulic telescopic rod 13 pushes the right-angle pressure block 12 to press it tightly against the middle of the steel bar. Then, the two servo motors 10 rotate simultaneously, driving the bending device 11 to bend the steel bar. After completion, the bending device 11 resets. Then, the servo motor 26 rotates to make the gear 7 rotate, which in turn makes the transmission gear rack 5 pass through the square slot 6, driving the blocks 3 and 4 sliding on the front and back sides inside the outer shell 1 to move closer to each other. After reaching the second bending point, the servo motor 10 rotates again, and the bending device 11 bends the steel bar a second time. After the bending ends and the bending device 11 resets, the hydraulic telescopic rod 13 retracts, and the steel bar slowly descends to the bottom of the arc-shaped slotted plate 8. At this time, the hydraulic telescopic rod 13 expands, and the right-angle pressure block 12 bends the steel bar a third time. Finally, the hydraulic telescopic rod 13 retracts, and the steel bar falls downwards. The bending of the steel bar reduces manual operation, achieves precise control of the bending angle and side length, and reduces safety hazards.

[0042] Before the device is operated, the threaded rod 209 with a handle is rotated to move the limiting plate 207 left and right to adapt to the length of the reinforcing bar. Then, the reinforcing bar is placed into the U-shaped guide rail composed of the horizontal plate 201, the limiting plate 208, and the grooved gear rack 202. Next, the servo motor 206 starts running, driving the gear 205 to rotate. Under the action of the gear rack on the grooved gear rack 202, the gear 205 causes the C-shaped frame 203 to move to the right. When the C-shaped frame 203 moves, it pushes the push plate 204, which in turn pushes the reinforcing bar to move to the right until one end of the reinforcing bar moves to the left side of the limiting plate 207. At this time, the push plate 204 and the limiting plate 207 clamp the two sides of the reinforcing bar until the middle of the reinforcing bar is clamped by the right-angle pressure block 12 and the arc-shaped slotted plate 8. Then, the push plate 204 moves to the left to release the left side of the reinforcing bar, thereby achieving the pushing of the reinforcing bar.

[0043] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A steel bar positioning and bending device for building construction, comprising a housing (1), characterized in that: A block 1 (3) is slidably connected to the right side of the inner wall of the outer shell (1), and a block 2 (4) is slidably connected to the left side of the inner wall of the outer shell (1). A transmission gear rack (5) is fixedly connected to the left front part of the outer wall of the block 1 (3). A square groove (6) is opened on the right side of the outer wall of the block 1 (3). A transmission gear rack (5) is fixedly connected to the right rear part of the outer wall of the block 2 (4). A square groove (6) is opened on the right side of the block 2 (4). A servo motor 3 (26) is fixedly connected to the top of the inner wall of the outer shell (1). A gear 2 (7) is fixedly connected to the output end of the servo motor 3 (26). The front and rear sides of the outer wall of the gear 2 (7) mesh with the two transmission gear racks (5). The inner walls of the first block (3) and the second block (4) are fixedly connected to the front side of the bottom of the inner wall with an arc-shaped slotted plate (8). The inner walls of the first block (3) and the second block (4) are fixedly connected to the rear side of the bottom of the inner wall with a semi-circular block (9). The bottom of the first block (3) and the second block (4) are fixedly connected to the bottom of the second servo motor (10). The output end of the second servo motor (10) is fixedly connected to a bending device (11). The inner wall of the outer shell (1) is fixedly connected to the middle of the front side with a hydraulic telescopic rod (13). One end of the hydraulic telescopic rod (13) is fixedly connected to a right-angle pressure block (12). The left side of the outer shell (1) is provided with a pushing mechanism (2). The pushing mechanism (2) is used to push the reinforcing bars.

2. The rebar positioning and bending device for building construction according to claim 1, characterized in that: The pushing mechanism (2) includes a horizontal plate (201), which is fixedly connected to the middle left side of the inner wall of the outer shell (1). A limit plate (208) is fixedly connected to the front top of the horizontal plate (201). A grooved gear rack (202) is fixedly connected to the middle top side of the horizontal plate (201). A C-shaped frame (203) is slidably connected to the rear side of the grooved gear rack (202). A push plate (204) is fixedly connected to the right side of the C-shaped frame (203). A servo motor (206) is fixedly connected to the left side of the frame (203). A gear (205) is fixedly connected to the output end of the servo motor (206). The outer wall of the gear (205) meshes with the grooved gear rack (202). A limit plate (207) is slidably connected to the left side of the outer shell (1). A threaded rod (209) with a handle is rotatably connected to the right side of the limit plate (207). The outer wall of the threaded rod (209) with a handle is threadedly connected to the outer shell (1).

3. The rebar positioning and bending device for building construction according to claim 1, characterized in that: An observation window (14) is provided on the front side of the outer shell (1), and a lighting lamp (15) is fixedly connected to the top side of the front part of the inner wall of the outer shell (1).

4. A rebar positioning and bending device for building construction according to claim 1, characterized in that: An alarm light (16) is fixedly connected to the rear side of the outer casing (1), and an alarm sounder (17) is fixedly connected to the left side of the alarm light (16).

5. A rebar positioning and bending device for building construction according to claim 1, characterized in that: The bottom of the inner wall of the outer shell (1) is slidably connected to a discharge drawer (18), and the top of the discharge drawer (18) is fixedly connected to a guide rod (19).

6. A rebar positioning and bending device for building construction according to claim 1, characterized in that: The bottom front and rear sides of the outer shell (1) are fixedly connected with legs (20), and the bottom of the legs (20) is fixedly connected with shock-absorbing pads (21).

7. A rebar positioning and bending device for building construction according to claim 2, characterized in that: A protective box (25) is fixedly connected to the top rear side of the horizontal plate (201), and an emergency brake button (24) is fixedly connected to the bottom front side of the inner wall of the protective box (25).

8. A rebar positioning and bending device for building construction according to claim 7, characterized in that: A length controller (23) is rotatably connected to the middle of the bottom side of the inner wall of the protective box (25), and a curvature controller (22) is rotatably connected to the right side of the bottom of the inner wall of the protective box (25).

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