Novel stamping equipment for vehicle accessory machining
By introducing multi-stage guiding, buffering, and auxiliary positioning structures into the stamping equipment, the problem of rigid collision between the upper and lower pressure plates is solved, the stamping accuracy and equipment life are improved, and the versatility and ease of operation of the equipment are enhanced.
Patent Information
- Application Number
- CN202511327365.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-17
- Publication Date
- 2025-11-18
AI Technical Summary
The lack of buffer devices in existing stamping dies leads to severe rigid collisions between the upper and lower pressure plates, which can easily damage the dies and affect production efficiency and quality.
The system employs a multi-stage guiding, buffering, and auxiliary positioning structure, including guide columns, buffering mechanisms, and lifting mechanisms, to ensure precise alignment of the upper and lower dies, reduce rigid collisions, and improve stamping accuracy and equipment lifespan through hydraulic cylinder drive and unloading spring buffering.
It effectively reduces rigid collisions during the stamping process, improves stamping accuracy and equipment lifespan, and enhances the equipment's versatility and ease of operation.
Smart Images

Figure CN120961698A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of stamping equipment, in particular to a new stamping equipment for vehicle accessory machining. BACKGROUND
[0002] Many accessories on the car are produced by stamping die, stamping die is a special process equipment for processing metal or non-metal materials into parts or semi-finished products in cold stamping processing. Stamping die plays an indispensable role in stamping forming process, greatly improving the production efficiency and production quality of products.
[0003] The stamping die generally includes an upper pressing plate and a lower pressing plate. In the process of stamping production, the upper pressing plate is driven by a cylinder to impact and extrude the lower pressing plate, thereby realizing the machining of accessories. However, in the prior art, no buffer device is designed between the upper pressing plate and the lower pressing plate during stamping of the lower pressing plate by the upper pressing plate. Due to the large impact force, the die is easily damaged.
[0004] Therefore, the present application provides a new stamping equipment for vehicle accessory machining to solve the above technical problems. SUMMARY
[0005] Therefore, it is necessary to provide a new stamping equipment for vehicle accessory machining to solve the above technical problems. The multi-stage guiding, buffering and auxiliary positioning structure ensures the accurate alignment of the upper die and the lower die during stamping, effectively reduces the rigid collision, and significantly improves the stamping precision and the service life of the equipment.
[0006] In order to solve the above technical problems, the present application adopts the following technical solutions:
[0007] A new stamping equipment for vehicle accessory machining is applied to vehicle accessory stamping machining.
[0008] The new stamping equipment for vehicle accessory machining specifically comprises:
[0009] A base, the upper part of the base is sequentially provided with a stamping lower die seat, a stamping upper die seat and a top frame from bottom to top; the upper end of the stamping lower die seat is fixedly connected with a stamping lower die block, the lower end of the stamping upper die seat is fixedly connected with a stamping upper die block, and vertical guide columns are arranged between the upper ends of the stamping lower die seat and the top frame; one end of the guide column is fixedly connected with the stamping lower die seat, and the other end of the guide column is fixedly connected with the top frame; the lower end of the top frame is provided with a lifting driving mechanism, and the lifting driving mechanism is used to drive the stamping upper die seat to move up and down;
[0010] The two ends of the stamping upper die seat are vertically and slidingly connected with guide columns at the same end, a buffer mechanism is arranged at the lower part of the guide column and at the position between the stamping lower die seat and the stamping upper die seat, and is used for buffering between the stamping lower die and the stamping upper die during stamping.
[0011] Two sides of the stamping lower die seat are provided with lifting mechanisms for lifting and supporting the stamping blank.
[0012] As a preferred embodiment of the novel stamping equipment for vehicle accessory machining provided by the application, the lifting driving mechanism comprises a hydraulic cylinder body, a hydraulic cylinder mounting rack is fixedly connected to the lower end of the top frame, the hydraulic cylinder body is fixed at the position inside the hydraulic cylinder mounting rack, and the telescopic end of the hydraulic cylinder body penetrates through the hydraulic cylinder mounting rack and is connected with the top of the stamping upper die seat.
[0013] As a preferred embodiment of the novel stamping equipment for vehicle accessory machining provided by the application, the buffer mechanism comprises a lower buffer cylinder, an upper buffer cylinder and a force relieving spring, the lower buffer cylinder is fixedly connected with the stamping lower die seat, the upper buffer cylinder is fixedly connected with the stamping upper die seat, the force relieving spring is located at the position between the lower buffer cylinder and the upper buffer cylinder, one end of the force relieving spring extends to the inside of the lower buffer cylinder, the other end of the force relieving spring extends to the inside of the upper buffer cylinder, the middle part of the upper buffer cylinder is fixedly connected with an upper limiting block, the middle part of the lower buffer cylinder is fixedly connected with a lower limiting block, the lower buffer cylinder, the upper buffer cylinder, the force relieving spring, the upper limiting block and the lower limiting block are coaxially arranged, the upper limiting block and the lower limiting block are located inside the force relieving spring, the upper buffer cylinder is slidingly connected with the guide column through the upper limiting block, and the lower buffer cylinder is slidingly connected with the guide column through the lower limiting block.
[0014] As a preferred embodiment of the novel stamping equipment for vehicle accessory machining provided by the application, the upper part of the stamping upper die seat is further provided with a positioning counterweight frame, the positioning counterweight frame is detachably fixedly connected with the stamping upper die seat, and the end part and the top frame end part of the stamping lower die seat are further vertically and fixedly connected with a positioning guide rod.
[0015] As a preferred embodiment of the novel stamping equipment for vehicle accessory machining provided by the application, the number of the lifting mechanisms is four, two lifting mechanisms are arranged at the two sides of the stamping lower die seat, and the two lifting mechanisms at the same side are arranged in parallel.
[0016] As a preferred embodiment of the novel stamping equipment for vehicle accessory machining provided by the application, the lifting mechanism comprises a movable arm, a mounting seat is rotatably connected to the lower end of the movable arm, the mounting seat is fixedly connected with the stamping lower die seat, a contact piece is rotatably connected to the upper end of the movable arm, an adjusting arm is further arranged above the movable arm, one end of the adjusting arm is rotatably connected with the stamping lower die seat, the other end of the adjusting arm is rotatably connected with a connecting sleeve, the connecting sleeve is slidably connected with the movable arm, and a limiting knob for movement limiting is further arranged on the outside of the connecting sleeve.
[0017] As a preferred embodiment of the novel stamping equipment for vehicle accessory machining provided by the application, the base comprises an outer frame, a conveying platform is arranged in the middle of the outer frame, guide rails are fixedly connected to the inner sides of the outer frame, movable seats are arranged on the guide rails, the movable seats can slide along the length direction of the guide rails, a plurality of weight wheels are arranged at the lower end of the movable seat, the bottom of the movable seat is slidably connected with the outer frame through the weight wheels, and the two sides of the stamping lower die seat are fixedly connected with the top of the two movable seats.
[0018] As a preferred embodiment of the novel stamping equipment for vehicle accessory machining provided by the application, the side surface of the guide rail is provided with a driving rod, the driving rod is threadedly connected with the corresponding movable seat, the driving rod is rotatably connected with the outer frame, the two driving rods are drivingly connected through a first transmission assembly, and a driving motor is further fixedly connected inside the outer frame, the output end of the driving motor is drivingly connected with one of the driving rods through a second transmission assembly.
[0019] Compared with the prior art, the application has the following beneficial effects:
[0020] The novel stamping equipment for vehicle accessory machining provided by the application ensures the accurate alignment of the upper die and the lower die in the stamping process through the multi-stage guiding, buffering and auxiliary positioning structure, effectively reduces the rigid collision, and significantly improves the stamping precision and the service life of the equipment.
[0021] The novel stamping equipment for vehicle accessory machining provided by the application is designed through the adjustable base and the liftable lifting support mechanism, can flexibly adapt to the blank machining requirements of different sizes and shapes, and enhances the universality and operation convenience of the equipment. BRIEF DESCRIPTION OF DRAWINGS
[0022] In order to more clearly illustrate the schemes in the application, the drawings needed in the following embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.
[0023] Figure 1 The overall structure schematic diagram of the new stamping equipment for vehicle accessory machining provided by the present application is shown in the figure.
[0024] Figure 2 The overall structure front view of the new stamping equipment for vehicle accessory machining provided by the present application is shown in the figure.
[0025] Figure 3 The structure schematic diagram of the lifting driving mechanism of the new stamping equipment for vehicle accessory machining provided by the present application is shown in the figure.
[0026] Figure 4 The structure schematic diagram of the buffer mechanism of the new stamping equipment for vehicle accessory machining provided by the present application is shown in the figure.
[0027] Figure 5 The structure schematic diagram of the positioning guide rod and the positioning counterweight frame of the new stamping equipment for vehicle accessory machining provided by the present application is shown in the figure.
[0028] Figure 6 The structure schematic diagram of the lifting mechanism of the new stamping equipment for vehicle accessory machining provided by the present application is shown in the figure.
[0029] Figure 7 The enlarged structure diagram of the lifting mechanism of the new stamping equipment for vehicle accessory machining provided by the present application is shown in the figure.
[0030] Figure 8 The structure schematic diagram of the base of the new stamping equipment for vehicle accessory machining provided by the present application is shown in the figure.
[0031] The figure mark description is as follows:
[0032] 1, base; 2, stamping lower die seat; 3, stamping lower die block; 4, stamping upper die seat; 5, stamping upper die block; 6, top frame; 7, guide column; 8, lifting driving mechanism; 9, buffer mechanism; 10, lifting mechanism; 11, hydraulic cylinder mounting frame; 12, hydraulic cylinder main body; 13, lower buffer cylinder; 14, upper buffer cylinder; 15, unloading spring; 16, upper limit block; 17, lower limit block; 18, positioning guide rod; 19, positioning counterweight frame; 20, sliding sleeve; 21, mounting seat; 22, movable arm; 23, contact piece; 24, adjusting arm; 25, connecting sleeve; 26, limit knob; 27, outer frame; 28, conveying platform; 29, guide rail; 30, movable seat; 31, weight wheel; 32, driving rod; 33, first transmission assembly; 34, driving motor; 35, second transmission assembly. DETAILED DESCRIPTION
[0033] In order to make the person skilled in the art better understand the technical scheme of the present application, the technical scheme in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor should belong to the scope of protection of the present application.
[0034] Embodiment one:
[0035] Please refer to Figure 1 - Figure 7 A new stamping equipment for vehicle accessory processing, comprising:
[0036] The base 1 is provided with a stamping lower die seat 2, a stamping upper die seat 4 and a top frame 6 from bottom to top in sequence; the upper end of the stamping lower die seat 2 is fixedly connected with a stamping lower module 3, the lower end of the stamping upper die seat 4 is fixedly connected with a stamping upper module 5, and vertical guide columns 7 are arranged between the upper ends of both ends of the stamping lower die seat 2 and the top frame 6, one end of the guide column 7 is fixedly connected with the stamping lower die seat 2, and the other end of the guide column 7 is fixedly connected with the top frame 6, which provides accurate guidance for the lifting movement of the stamping upper die seat 4, ensures that the stamping upper module 5 can be accurately aligned with the stamping lower module 3, and improves the stamping quality; the lower end of the top frame 6 is provided with a lifting driving mechanism 8, which is used to drive the stamping upper die seat 4 to move up and down, so as to realize the stamping action; specifically, the lifting driving mechanism 8 comprises a hydraulic cylinder main body 12, the lower end of the top frame 6 is fixedly connected with a hydraulic cylinder mounting frame 11, the hydraulic cylinder main body 12 is fixed at the position inside the hydraulic cylinder mounting frame 11, and the telescopic end of the hydraulic cylinder main body 12 penetrates through the hydraulic cylinder mounting frame 11 and is connected with the top of the stamping upper die seat 4.
[0037] The two ends of the upper stamping die base 4 are vertically and slidingly connected with the guide columns 7 at the same end, so as to ensure the stability of the upper stamping die base 4 during the lifting process. The lower part of the guide column 7 is provided with a buffer mechanism 9 at the position between the lower stamping die base 2 and the upper stamping die base 4, which is used for buffering between the lower stamping die base 3 and the upper stamping die base 5 during the stamping process. Specifically, the buffer mechanism 9 comprises a lower buffer cylinder 13, an upper buffer cylinder 14 and a force relief spring 15. The lower buffer cylinder 13 is fixedly connected with the lower stamping die base 2, the upper buffer cylinder 14 is fixedly connected with the upper stamping die base 4, and the force relief spring 15 is located between the lower buffer cylinder 13 and the upper buffer cylinder 14. One end of the force relief spring 15 extends to the inside of the lower buffer cylinder 13, and the other end of the force relief spring 15 extends to the inside of the upper buffer cylinder 14. The middle part of the upper buffer cylinder 14 is fixedly connected with an upper limiting block 16, and the middle part of the lower buffer cylinder 13 is fixedly connected with a lower limiting block 17. The lower buffer cylinder 13, the upper buffer cylinder 14, the force relief spring 15, the upper limiting block 16 and the lower limiting block 17 are coaxially arranged, and the upper limiting block 16 and the lower limiting block 17 are located inside the force relief spring 15. The upper buffer cylinder 14 is slidingly connected with the guide column 7 through the upper limiting block 16, and the lower buffer cylinder 13 is slidingly connected with the guide column 7 through the lower limiting block 17, so that the buffer mechanism 9 can buffer while not affecting the normal sliding of the upper stamping die base 4 along the guide column 7.
[0038] The two sides of the lower stamping die base 2 are provided with lifting mechanisms 10, which are used for supporting and lifting the stamping blank, and facilitate the placement and removal of the blank. The number of the lifting mechanisms 10 is four, and two lifting mechanisms 10 are arranged on each side of the lower stamping die base 2. The two lifting mechanisms 10 on the same side are arranged in parallel to provide uniform and stable support force.
[0039] Further, the upper stamping die base 4 is further provided with a positioning counterweight frame 19, which is detachably fixedly connected with the upper stamping die base 4. The end part of the lower stamping die base 2 and the end part of the top frame 6 are further vertically fixedly connected with a positioning guide rod 18. The end part of the positioning counterweight frame 19 is vertically and slidingly connected with the positioning guide rod 18 at the same end through a sliding sleeve 20.
[0040] As can be seen from the above, during work, first, the blank to be stamped is placed on the lifting mechanism 10, and the lifting mechanism 10 plays a preliminary supporting role on the blank. Then, the lifting driving mechanism 8 is started, the telescopic end of the hydraulic cylinder main body 12 is extended, and the upper stamping die base 4 is pushed to move downward along the guide column 7. During the descending process of the upper stamping die base 4, the positioning counterweight frame 19 slides along the positioning guide rod 18 through the sliding sleeve 20, which plays the role of auxiliary positioning, guiding and counterweighting, ensures the vertical descent of the upper stamping die base 4, further enhances the stability of the equipment structure, ensures the accurate relative position between the components during the stamping process, and improves the stamping precision.
[0041] When the upper die holder 4 drives the upper die module 5 to approach the lower die module 3, the buffer mechanism 9 begins to work. The upper buffer cylinder 14 first contacts the unloading spring 15, and the unloading spring 15 is compressed to absorb part of the impact force, reduce the rigid collision between the lower die module 3 and the upper die module 5 during the stamping process, protect the mold and equipment, and prolong the service life. With the continuous pushing of the hydraulic cylinder body 12, the upper die module 5 and the lower die module 3 complete the die closing, and the blank is stamped to form the required vehicle accessory shape. After the stamping is completed, the telescopic end of the hydraulic cylinder body 12 is retracted, driving the upper die holder 4 and the upper die module 5 to rise, thus completing a stamping process.
[0042] Embodiment two:
[0043] The new type of stamping equipment for vehicle accessory processing provided in embodiment one is further optimized, and specifically, as shown in Figure 8 The base 1 comprises an outer frame 27, the middle part of the outer frame 27 is provided with a conveying platform 28, both sides of the inner side of the outer frame 27 are fixedly connected with guide rails 29, the guide rails 29 are provided with movable seats 30, the movable seats 30 can slide along the length direction of the guide rails 29, the lower end of the movable seat 30 is provided with a plurality of weight wheels 31, the bottom of the movable seat 30 is slidably connected with the outer frame 27 through the weight wheels 31, and the two sides of the lower die holder 2 are respectively fixedly connected with the top of the two movable seats 30.
[0044] Further, in order to realize the driving of the movable seat 30 to adjust the position of the lower die holder 2, the side surface of the guide rail 29 is provided with a driving rod 32, the driving rod 32 is threadedly connected with the corresponding movable seat 30, the driving rod 32 is rotatably connected with the outer frame 27, the two driving rods 32 are drivingly connected through a first transmission assembly 33, and the inner side of the outer frame 27 is further fixedly connected with a driving motor 34. The output end of the driving motor 34 is drivingly connected with one of the driving rods 32 through a second transmission assembly 35.
[0045] Through the above structure design, on the basis of embodiment one, when it is necessary to adjust the position of the lower die holder 2, the driving motor 34 is started, and the driving motor 34 drives one of the driving rods 32 to rotate through the second transmission assembly 35. Since the two driving rods 32 are drivingly connected through the first transmission assembly 33, the other driving rod 32 will also rotate synchronously. When the driving rod 32 rotates, the movable seat 30 threadedly connected with the driving rod 32 slides along the length direction of the guide rail 29 under the limitation of the guide rail 29. The weight wheels 31 at the lower end of the movable seat 30 assist the sliding to reduce the friction force, so that the sliding is smoother. The movable seat 30 drives the lower die holder 2 to move, so as to realize the adjustment of the position of the lower die holder 2, so as to meet the stamping requirements of blanks of different sizes or shapes, and improve the versatility and flexibility of the equipment. After the adjustment is completed, the stamping processing operation can be carried out according to the working principle of embodiment one.
[0046] Embodiment Three
[0047] The new type of stamping equipment for processing vehicle accessories provided in Embodiment One is further optimized, specifically, as shown in Figure 7 The lifting mechanism 10 includes a movable arm 22, the lower end of the movable arm 22 is rotatably connected with a mounting seat 21, the mounting seat 21 is fixedly connected with the stamping lower die seat 2, the upper end of the movable arm 22 is rotatably connected with a contact piece 23 for directly contacting and supporting the blank, an adjusting arm 24 is further arranged above the movable arm 22, one end of the adjusting arm 24 is rotatably connected with the stamping lower die seat 2, the other end of the adjusting arm 24 is rotatably connected with a connecting sleeve 25, the connecting sleeve 25 is slidably connected with the movable arm 22, when the movable arm 22 rotates around the mounting seat 21, the connecting sleeve 25 will slide on the movable arm 22, so as to realize the lifting movement of the contact piece 23, facilitating the placing and taking out of the blank, a limiting knob 26 for movement limiting is further arranged on the outer side of the connecting sleeve 25, the movement of the connecting sleeve 25 can be limited by tightening the limiting knob 26, thereby realizing the movement limitation of the movable arm 22, the height positioning of the contact piece 23, and ensuring the normal operation of the lifting and supporting mechanism.
Claims
1. A novel stamping equipment for processing vehicle parts, characterized in that, include: A base (1) is provided above the base (1) from bottom to top, consisting of a lower stamping die base (2), an upper stamping die base (4), and a top frame (6). The upper end of the lower stamping die base (2) is fixedly connected to a lower stamping module (3), and the lower end of the upper stamping die base (4) is fixedly connected to an upper stamping module (5). Guide columns (7) are vertically arranged between the two ends of the upper end of the lower stamping die base (2) and the top frame (6). One end of the guide column (7) is fixedly connected to the lower stamping die base (2), and the other end of the guide column (7) is fixedly connected to the top frame (6). A lifting drive mechanism (8) is provided at the lower end of the top frame (6). The lifting drive mechanism (8) is used to drive the upper stamping die base (4) to move up and down. Both ends of the upper stamping die (4) are vertically slidably connected to the guide post (7) at the same end. A buffer mechanism (9) is provided at the lower part of the guide post (7) and at the position between the lower stamping die (2) and the upper stamping die (4) for buffering between the lower stamping die (3) and the upper stamping die (5) during the stamping process. Both sides of the stamping die base (2) are provided with a lifting mechanism (10) for supporting the stamping blank.
2. The novel stamping equipment for processing vehicle parts according to claim 1, characterized in that, The lifting drive mechanism (8) includes a hydraulic cylinder body (12). The lower end of the top frame (6) is fixedly connected to a hydraulic cylinder mounting bracket (11). The hydraulic cylinder body (12) is fixed inside the hydraulic cylinder mounting bracket (11). The telescopic end of the hydraulic cylinder body (12) passes through the hydraulic cylinder mounting bracket (11) and is connected to the top of the stamping upper die base (4).
3. The novel stamping equipment for processing vehicle parts according to claim 1, characterized in that, The buffer mechanism (9) includes a lower buffer cylinder (13), an upper buffer cylinder (14), and a stress relief spring (15). The lower buffer cylinder (13) is fixedly connected to the lower stamping die base (2), and the upper buffer cylinder (14) is fixedly connected to the upper stamping die base (4). The stress relief spring (15) is located between the lower buffer cylinder (13) and the upper buffer cylinder (14). One end of the stress relief spring (15) extends to the inside of the lower buffer cylinder (13), and the other end extends to the inside of the upper buffer cylinder (14). The middle of the upper buffer cylinder (14)... The upper buffer cylinder (14) is fixedly connected to the upper buffer cylinder (15), and the lower buffer cylinder (13) is fixedly connected to the middle of the upper buffer cylinder (17). The lower buffer cylinder (13), the upper buffer cylinder (14), the unloading spring (15), the upper buffer cylinder (16), and the lower buffer cylinder (17) are coaxially arranged. The upper buffer cylinder (16) and the lower buffer cylinder (17) are located inside the unloading spring (15). The upper buffer cylinder (14) is slidably connected to the guide post (7) through the upper buffer cylinder (16), and the lower buffer cylinder (13) is slidably connected to the guide post (7) through the lower buffer cylinder (17).
4. The novel stamping equipment for processing vehicle parts according to claim 1, characterized in that, A positioning counterweight frame (19) is also provided above the upper stamping die base (4). The positioning counterweight frame (19) is detachably and fixedly connected to the upper stamping die base (4). The end of the lower stamping die base (2) and the end of the top frame (6) are also vertically and fixedly connected to a positioning guide rod (18). The end of the positioning counterweight frame (19) is vertically and slidably connected to the positioning guide rod (18) at the same end through a sliding sleeve (20).
5. The novel stamping equipment for processing vehicle parts according to claim 1, characterized in that, The number of the lifting mechanisms (10) is four. Two lifting mechanisms (10) are provided on both sides of the stamping lower die base (2), and the two lifting mechanisms (10) on the same side are arranged in parallel.
6. The novel stamping equipment for processing vehicle parts according to claim 5, characterized in that, The lifting mechanism (10) includes a movable arm (22), the lower end of which is rotatably connected to a mounting base (21), the mounting base (21) being fixedly connected to a stamping lower die base (2), the upper end of which is rotatably connected to a contact element (23), and an adjusting arm (24) is also provided above the movable arm (22). One end of the adjusting arm (24) is rotatably connected to the stamping lower die base (2), and the other end of the adjusting arm (24) is rotatably connected to a connecting sleeve (25). The connecting sleeve (25) is slidably connected to the movable arm (22), and a limiting knob (26) for movement limitation is also provided on the outside of the connecting sleeve (25).
7. The novel stamping equipment for processing vehicle parts according to claim 1, characterized in that, The base (1) includes an outer frame (27), a conveying platform (28) is provided in the middle of the outer frame (27), and guide rails (29) are fixedly connected to both sides of the inner side of the outer frame (27). Movable seats (30) are provided on the guide rails (29). The movable seats (30) can slide along the length direction of the guide rails (29). Multiple load wheels (31) are provided at the lower end of the movable seats (30). The bottom of the movable seats (30) is slidably connected to the outer frame (27) through the load wheels (31). The two sides of the stamping die base (2) are fixedly connected to the top of the two movable seats (30) respectively.
8. The novel stamping equipment for processing vehicle parts according to claim 7, characterized in that, A drive rod (32) is provided on the side of the guide rail (29). The drive rod (32) is threadedly connected to the corresponding movable seat (30). The drive rod (32) is rotatably connected to the outer frame (27). The two drive rods (32) are connected by a first transmission component (33). A drive motor (34) is also fixedly connected inside the outer frame (27). The output end of the drive motor (34) is connected to one of the drive rods (32) by a second transmission component (35).