Tarpaulin jacking and rolling device for truck

Abstract

The utility model discloses a tarpaulin jacking and rolling device for a truck, which relates to the technical field of truck tarpaulin rolling and comprises two groups of longitudinal beams, a transverse plate fixed at the tops of the longitudinal beams and height fixing frames fixedly mounted on two sides of the transverse plate, and the longitudinal beams are symmetrically mounted on two sides of the bottom of the transverse plate. A sliding frame is jointly slidably mounted on the surfaces of the two longitudinal beams, and a top plate is fixedly mounted at the top of the transverse plate. The telescopic winding mechanism is arranged to drive and change the winding width, meanwhile, the standby telescopic overhauling mechanism can guarantee the tarpaulin arrangement and winding operation under the condition that the main lifting structure fails, and in cooperation with the jacking driving mechanism, the ultimate height can be achieved, and convenience is provided for tarpaulin arrangement and overhauling operation; the problems that in the background technology, a rolling shaft with the fixed width and tarpaulin borne by the rolling shaft easily exceed the width limit of a truck body, and when goods with different loading heights are loaded, an existing device lacks an effective adaptive adjusting mechanism are solved.

Description

Technical Field

[0001] This utility model relates to the field of truck tarpaulin winding technology, specifically to a truck tarpaulin lifting and winding device. Background Technology

[0002] In the truck transportation sector, tarpaulins are widely used to protect goods from wind and rain, prevent cargo from scattering, and meet environmental protection requirements. Traditionally, the operation of taking up and taking down truck tarpaulins relies mainly on manual labor. Drivers need to climb onto the truck bed to arrange and roll them up, which is not only inefficient but also poses safety hazards due to working at height. A slight mistake could lead to a fall and endanger the driver's life.

[0003] While some existing tarpaulin winding devices have achieved mechanization to some extent and reduced the burden of manual labor, they still have many shortcomings. For example, common winding shaft structures are fixed and their width is not adjustable. When trucks travel on narrow streets or make turns, the fixed-width winding shaft and the tarpaulin it carries can easily exceed the truck's width limit, increasing the risk of scraping against surrounding obstacles and potentially violating traffic regulations, thus affecting road safety and smooth traffic flow.

[0004] Meanwhile, existing equipment lacks an effective adaptive adjustment mechanism when dealing with goods of varying loading heights. If the load is high, conventionally high-height winding devices struggle to properly wind up and unwind the tarpaulin; adjusting the winding device height often requires additional tools or equipment, making the process cumbersome, time-consuming, and labor-intensive. This not only reduces the operational efficiency of trucks but may also lead to equipment damage and increased maintenance costs due to frequent adjustments.

[0005] In conclusion, developing a truck tarpaulin lifting and rewinding device that can flexibly adjust the width of the rewind shaft, adapt to different driving scenarios, and has a convenient lifting function to cope with different cargo loading heights has become an important problem that the truck transportation industry urgently needs to solve. Utility Model Content

[0006] The purpose of this invention is to provide a tarpaulin lifting and rewinding device for trucks to solve the problems mentioned in the background art.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0008] A truck tarpaulin lifting and rewinding device includes longitudinal beams, a cross plate fixed to the top of the longitudinal beams, and a height-fixing frame slidably installed on both sides of the cross plate. Two sets of longitudinal beams are provided and symmetrically installed on both sides of the bottom of the cross plate. A sliding frame is slidably installed on the surface of both sets of longitudinal beams. A top plate is provided on the top of the cross plate. The bottom of the top plate is fixedly installed with the bottom of the height-fixing frame. The back of the longitudinal beams is fixed to the truck bed. The outer surface of the sliding frame slides in cooperation with the inner wall of the height-fixing frame. A telescopic rewinding mechanism is fixedly installed on the top of the top plate.

[0009] The top of the front of the sliding frame is provided with a maintenance platform, and the bottom of the maintenance platform is provided with a spare telescopic maintenance mechanism, which is used to drive the maintenance platform to be raised and lowered on the sliding frame.

[0010] A lifting drive mechanism is provided on the inner side of the longitudinal beam, which is used to drive the sliding frame to rise and fall.

[0011] A further improvement of this utility model's technical solution lies in the following: the telescopic winding mechanism includes a dual-axis motor, a first threaded sleeve block, a first screw rod, a connecting frame, a telescopic cylinder, a limiting bolt, a limiting groove, a winding drum, and a roller motor. The dual-axis motor is fixedly installed at the center of the top of the top plate. The first screw rod has two sets symmetrically installed on the output ends of both sides of the dual-axis motor. The first threaded sleeve block is threadedly connected to the surface of the dual-axis motor and slides in cooperation with the top of the top plate. The connecting frame is fixedly installed on the top of the first threaded sleeve block. The roller motor is fixedly installed inside the telescopic cylinder. The telescopic cylinder is slidably installed at both ends of the winding drum. The limiting groove is opened on both sides of the front of the winding drum. The threaded end of the limiting bolt is fixedly installed with the telescopic cylinder and slides in cooperation with the inner wall of the limiting groove. The output end of the roller motor is fixedly installed with the inner side of the connecting frame.

[0012] Using the above technical solution, the dual-axis motor can drive the screw to rotate. When the symmetrical screw rotates, it can drive the threaded sleeve blocks to move closer and further apart. When the threaded sleeve blocks move closer together, they can drive the connecting frame to move closer together for retraction. During retraction, the limiting groove allows the telescopic cylinder to slide laterally while ensuring that the internal roller motor can drive the take-up drum to rotate after starting. The limiting bolt can prevent the telescopic cylinder from separating from the take-up drum.

[0013] A further improvement of the present invention is that the backup telescopic maintenance mechanism includes a support frame and a scissor-type lifting frame. The support frame is fixedly installed on both sides of the front of the sliding frame, and the scissor-type lifting frame is fixedly installed on the top of the support frame. The top of the scissor-type lifting frame is fixedly installed with the bottom of the maintenance platform.

[0014] The above technical solution supports the scissor lift frame and, after the scissor lift frame is started, it can lift the maintenance platform upward, making it convenient for truck drivers to arrange or maintain the tarpaulin. The scissor lift frame can be used when the lifting drive mechanism fails, and with the cooperation of the lifting drive mechanism, it can stand higher to facilitate the arrangement and tightening of the ropes on the top of the tarpaulin.

[0015] A further improvement of the present invention is that the lifting drive mechanism includes a winch, a wire rope, a fixing lug, and a hanging wheel. The winch is located at the bottom of the back of the truck cab. The hanging wheel is fixedly installed at the center of the bottom of the cross plate. One end of the wire rope is fixedly installed to the output end of the winch. The other end of the wire rope passes through the hanging wheel from top to bottom and is fixedly installed to the fixing lug. The fixing lug is fixedly installed on the top of the back of the sliding frame. The roller of the hanging wheel slides in cooperation with the wire rope.

[0016] Using the above technical solution, after the winch is started, the wire rope can be lifted upward by the scissor-type lifting frame through the top support of the gantry wheel. Then, the fixed ear drives the sliding frame to adjust its height, so that the sliding frame is raised to the required height, which makes it easier to arrange the tarpaulin and some goods.

[0017] A further improvement of the present invention is that the lifting drive mechanism further includes a lifting motor, a second screw, and a second screw sleeve block. The lifting motor is fixedly installed at the bottom of the longitudinal beam, the second screw is fixedly installed at the output end of the lifting motor, and the second screw sleeve block is fixedly installed on the side of the sliding frame near the longitudinal beam and is threadedly connected to the second screw.

[0018] In the above technical solution, after the lifting motor is started, it can drive the screw two to rotate. Then, the rotating screw two drives the screw sleeve block two to rise upward, thereby driving the sliding frame fixed thereto to rise upward for height adjustment.

[0019] A further improvement of the present invention is that the lifting drive mechanism further includes a base plate, a hydraulic rod, and a lifting truss. The base plate is fixedly installed at the bottom of the longitudinal beam, the hydraulic rod is fixedly installed at the top center of the base plate, the lifting truss is fixedly installed at the top of the inner side of the sliding frame, and the output end of the hydraulic rod is fixedly installed at the bottom of the lifting truss.

[0020] In the above technical solution, the base plate can provide fixed support for the hydraulic rod. After the hydraulic rod is started, it can drive the lifting truss to move upward through the output end. Then, the sliding frame fixed to the lifting truss can drive the sliding frame to lift upward, thereby achieving height adjustment.

[0021] A further improvement of this utility model is that: the front of the height-fixing frame is provided with positioning holes, and five sets of positioning holes are provided; electromagnetic spring pins are fixedly installed on both sides of the support frame, and the electromagnetic spring pins are inserted into the positioning holes.

[0022] Using the above technical solution, the positioning hole can provide five levels of lockable height. When the required height is reached, the electromagnetic spring pin can be de-energized, reducing the internal magnetic force. Under the action of the spring, it is inserted into the positioning hole to fix the height.

[0023] Due to the adoption of the above technical solution, the technological progress achieved by this utility model compared to the prior art is as follows:

[0024] This utility model provides a tarpaulin lifting and rewinding device for trucks. By setting a telescopic rewinding mechanism to drive and change the rewinding width, and by using a backup telescopic maintenance mechanism, the tarpaulin can be rewound and tidied even if the main lifting structure fails. In addition, in conjunction with the lifting drive mechanism, it can reach the maximum height to provide convenience for tarpaulin rewinding and maintenance operations. This solves the problems in the background art, such as the fixed width of the rewinding shaft and the tarpaulin it carries easily exceeding the width limit of the truck body, and the lack of an effective adaptive adjustment mechanism for existing devices when dealing with goods of different loading heights. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of this utility model;

[0026] Figure 2 This is a three-dimensional structural diagram of the back of this utility model;

[0027] Figure 3 This is a schematic diagram of the second type of lifting drive mechanism of this utility model;

[0028] Figure 4 This is a schematic diagram of the third type of lifting drive mechanism of this utility model.

[0029] In the diagram: 1. Longitudinal beam; 2. Height-fixing frame; 21. Positioning hole; 22. Electromagnetic spring pin; 3. Horizontal plate; 4. Sliding frame; 41. Support frame; 42. Scissor-type lifting frame; 43. Maintenance platform; 51. Winch; 52. Wire rope; 53. Fixing lug; 54. Hanging wheel; 501. Lifting motor; 502. Screw rod II; 503. Screw sleeve block II; 510. Base plate; 520. Hydraulic rod; 530. Lifting truss; 6. Top plate; 61. Dual-shaft motor; 62. Screw sleeve block I; 63. Screw rod I; 64. Connecting frame; 65. Telescopic cylinder; 66. Limit bolt; 67. Limit groove; 68. Winding drum; 69. Drum motor; 621. Sliding rail. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to embodiments:

[0031] Example 1

[0032] like Figure 1-4 As shown, this utility model provides a tarpaulin lifting and winding device for trucks, including a longitudinal beam 1, a horizontal plate 3 fixed to the top of the longitudinal beam 1, and a height-fixing frame 2 slidably installed on both sides of the horizontal plate 3. The longitudinal beam 1 is provided in two sets, symmetrically installed on both sides of the bottom of the horizontal plate 3. A sliding frame 4 is slidably installed on the surface of both sets of longitudinal beams 1. A top plate 6 is provided on the top of the horizontal plate 3, and the bottom of the top plate 6 is fixedly installed to the bottom of the height-fixing frame 2. The back of the longitudinal beam 1 is fixed to the truck bed. The outer surface of the sliding frame 4 slides against the inner wall of the height-fixing frame 2. A telescopic winding mechanism is fixedly installed on the top of the top plate 6. The telescopic winding mechanism includes a dual-shaft motor 61, a screw sleeve block 62, a screw rod 63, a connecting frame 64, a telescopic cylinder 65, and a limiting screw. Bolt 66, limiting groove 67, take-up drum 68 and roller motor 69, dual-shaft motor 61 is fixedly installed at the center of the top of top plate 6, screw 63 is provided in two sets and symmetrically installed on the output ends of dual-shaft motor 61 on both sides, screw sleeve block 62 is threadedly connected to the surface of dual-shaft motor 61 and slides with the top of top plate 6, connecting frame 64 is fixedly installed on the top of screw sleeve block 62, roller motor 69 is fixedly installed inside telescopic cylinder 65, telescopic cylinder 65 is slidably installed at both ends of take-up drum 68, limiting groove 67 is opened on both sides of the front of take-up drum 68, the threaded end of limiting bolt 66 is fixedly installed with telescopic cylinder 65 and slides with the inner wall of limiting groove 67, and the output end of roller motor 69 is fixedly installed with the inner side of connecting frame 64;

[0033] A maintenance platform 43 is provided on the top of the front of the sliding frame 4. A spare telescopic maintenance mechanism is fixedly installed at the bottom of the maintenance platform 43 and is used to drive the maintenance platform 43 to lift and lower on the sliding frame 4. The spare telescopic maintenance mechanism includes a support frame 41 and a scissor-type lifting frame 42. The support frame 41 is fixedly installed on both sides of the front of the sliding frame 4, and the scissor-type lifting frame 42 is fixedly installed on the top of the support frame 41. The top of the scissor-type lifting frame 42 is fixedly installed with the bottom of the maintenance platform 43.

[0034] A lifting drive mechanism is provided on the inner side of the longitudinal beam 1. The lifting drive mechanism is used to drive the sliding frame 4 to lift and lower.

[0035] In this embodiment, starting the dual-axis motor 61 can drive the screw 63 to rotate. When the symmetrical screw 63 rotates, it can drive the screw sleeve blocks 62 to move closer and further apart. When the screw sleeve blocks 62 move closer together, they can drive the connecting frame 64 to move closer together and retract. During retraction, the limiting groove 67 can facilitate the lateral sliding of the telescopic cylinder 65 while ensuring that the internal roller motor 69 can drive the take-up drum 68 to rotate after starting. The limiting bolt 66 can prevent the telescopic cylinder 65 from separating from the take-up drum 68. The support frame 41 can support the scissor-type lifting frame 42. After starting the scissor-type lifting frame 42, it can drive the maintenance platform 43 to be lifted upward, which is convenient for the truck driver to arrange or maintain the tarpaulin. The scissor-type lifting frame 42 can be used when the lifting drive mechanism fails. With the cooperation of the lifting drive mechanism, it can stand higher to facilitate the arrangement and tightening of the ropes on the top of the tarpaulin.

[0036] Example 2

[0037] like Figure 1-4 As shown, based on Embodiment 1, this utility model provides a technical solution: Preferably, the lifting drive mechanism includes a winch 51, a wire rope 52, a fixing lug 53, and a sheave 54. The winch 51 is located at the bottom of the back of the truck cab. The sheave 54 is fixedly installed at the center of the bottom of the horizontal plate 3. One end of the wire rope 52 is fixedly installed to the output end of the winch 51, and the other end of the wire rope 52 passes through the sheave 54 from top to bottom and is fixedly installed to the fixing lug 53. The fixing lug 53 is fixedly installed on the top of the back of the sliding frame 4. The roller of the sheave 54 slides in cooperation with the wire rope 52. The lifting drive mechanism also includes a lifting motor 501, a second screw 502, and a second screw sleeve block 503. The lifting motor 501 is fixedly installed at the bottom of the longitudinal beam 1, and the second screw sleeve block 503... 502 is fixedly installed at the output end of the lifting motor 501. The second screw sleeve block 503 is fixedly installed on the side of the sliding frame 4 near the longitudinal beam 1 and is threadedly connected to the second screw 502. The lifting drive mechanism also includes a base plate 510, a hydraulic rod 520 and a lifting truss 530. The base plate 510 is fixedly installed at the bottom of the longitudinal beam 1. The hydraulic rod 520 is fixedly installed at the top center of the base plate 510. The lifting truss 530 is fixedly installed at the top of the inner side of the sliding frame 4. The output end of the hydraulic rod 520 is fixedly installed at the bottom of the lifting truss 530. The front of the fixed height frame 2 is provided with positioning holes 21. Five sets of positioning holes 21 are provided. Electromagnetic spring pins 22 are fixedly installed on both sides of the support frame 41. The electromagnetic spring pins 22 are inserted into the positioning holes 21.

[0038] In this embodiment, after the winch 51 is started, the wire rope 52, supported by the top of the sheave 54, lifts the fixed lug 53 upward through the scissor-type lifting frame 42. The fixed lug 53 then drives the sliding frame 4 to adjust its height, raising it to the required height. This facilitates the handling of tarpaulins and some goods. After the lifting motor 501 is started, it drives the screw 502 to rotate. The rotating screw 502 then drives the screw sleeve 503 to rise, thereby lifting the fixed sliding frame 4 upward. The height can be adjusted. The base plate 510 can fix and support the hydraulic rod 520. After the hydraulic rod 520 is started, it can drive the lifting truss 530 to move upward through the output end. Then, the sliding frame 4 fixed to the lifting truss 530 can drive the sliding frame 4 to be lifted upward to realize the height adjustment. Through the hole 21, five locked heights can be provided. When the required height is reached, the electromagnetic spring pin 22 can be de-energized to reduce the internal magnetic force. Under the action of the spring, it is inserted into the positioning hole 21 to fix the height.

[0039] The working principle of the tarpaulin lifting and rewinding device for this truck will be explained in detail below.

[0040] like Figure 1-4 As shown, when the truck driver needs to roll up the tarpaulin, he can adjust the telescopic winding mechanism according to the actual needs, start the dual-shaft motor 61, and drive the screw 63 to rotate at its two output ends. The symmetrical screw 63 drives the screw sleeve block 62 to slide along the top of the top plate 6 through the thread transmission, so that they move closer or further apart, thereby driving the connecting frame 64 and the winding drum 68 installed on it to extend and retract synchronously. The telescopic cylinders 65 at both ends of the winding drum 68 can slide in the limiting groove 67. The limiting bolt 66 not only ensures the freedom of the telescopic cylinder 65 to move laterally, but also prevents it from separating from the winding drum 68. When the winding drum 68 is adjusted to a suitable width, the roller motor 69 starts and drives the winding drum 68 to rotate, thus completing the tarpaulin winding.

[0041] Furthermore, when the cargo in the truck bed is high, the height of the first drive sliding frame 4 can be changed, and then fixed with the corresponding positioning hole 21 by the electromagnetic spring pin 22, so that the sliding frame 4, the height-fixing frame 2, and the top plate 6 form a movable whole. Thus, the sliding frame 4 can be driven to adjust the height of the winding drum 68 on the top plate 6 to accommodate the items behind the truck bed.

[0042] When adjusting the tarpaulin, the driver can operate the lifting drive mechanism. If a winch 51, wire rope 52, and pulley 54 structure is used, this structure has a large adjustment stroke. Activating the winch 51 at the bottom of the truck cab rear, the pulley 54 changes the direction of tension in the wire rope 52, lifting the fixed lug 53 and causing the sliding frame 4 to rise. If a lifting motor 501, screw 502, and bolt block 503 structure is used, this structure has a medium stroke and requires a spare telescopic maintenance mechanism to reach the maximum height. The lifting motor 501 drives the screw 502 to rotate, driving the bolt block 503 to lift the sliding frame 4 upwards. If a base plate 510, hydraulic rod 520, and top... The lifting truss 530 structure has a large driving force but a short stroke. For higher positions, a backup telescopic maintenance mechanism is needed to lift to the limit position. After the hydraulic rod 520 is activated, it pushes the lifting truss 530, which drives the sliding frame 4 to rise. When the sliding frame 4 rises to a suitable height, the scissor-type lifting frame 42 can further lift the maintenance platform 43 upward, making it easier for the driver to arrange or maintain the tarpaulin. At the same time, the electromagnetic spring pin 22 cooperates with the positioning hole 21 on the fixed height frame 2 to lock the sliding frame 4 at five different heights, ensuring safe and stable operation. If the lifting drive mechanism fails, the scissor-type lifting frame 42 of the backup telescopic maintenance mechanism can still work independently, ensuring that the driver can complete the necessary operations.

[0043] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the protection scope of the present invention.

Claims

1. A tarpaulin lifting and rolling device for a truck, comprising a longitudinal beam (1), a horizontal plate (3) fixed on the top of the longitudinal beam (1), and a height fixing frame (2) slidingly installed on both sides of the horizontal plate (3), characterized in that: The longitudinal beams (1) are provided in two sets and are symmetrically installed on both sides of the bottom of the horizontal plate (3). The surfaces of the two sets of longitudinal beams (1) are slidably installed with sliding frames (4). The top of the horizontal plate (3) is provided with a top plate (6). The bottom of the top plate (6) is fixedly installed with the bottom of the fixed height frame (2). The back of the longitudinal beams (1) is fixed with the truck bed of the outside. The outer surface of the sliding frame (4) is slidably engaged with the inner wall of the fixed height frame (2). The top of the top plate (6) is fixedly installed with a telescopic winding mechanism. The top of the front of the sliding frame (4) is provided with a maintenance platform (43), and the bottom of the maintenance platform (43) is provided with a spare telescopic maintenance mechanism, which is used to drive the maintenance platform (43) to rise and fall on the sliding frame (4). The inner side of the longitudinal beam (1) is provided with a lifting drive mechanism, which is used to drive the sliding frame (4) to rise and fall.

2. A tarpaulin raising and rolling device for a truck according to claim 1, characterized in that: The telescopic winding mechanism includes a dual-axis motor (61), a screw sleeve block (62), a screw rod (63), a connecting frame (64), a telescopic cylinder (65), a limiting bolt (66), a limiting groove (67), a winding drum (68), and a roller motor (69). The dual-axis motor (61) is fixedly installed at the center of the top of the top plate (6). Two sets of screw rods (63) are symmetrically installed on the output ends of the dual-axis motor (61) on both sides. The screw sleeve block (62) is threadedly connected to the surface of the dual-axis motor (61) and is connected to the top plate (6). The top of the connecting frame (64) is fixedly installed on the top of the screw sleeve block (62). The roller motor (69) is fixedly installed inside the telescopic cylinder (65). The telescopic cylinder (65) is slidably installed at both ends of the take-up drum (68). The limiting groove (67) is opened on both sides of the front of the take-up drum (68). The threaded end of the limiting bolt (66) is fixedly installed with the telescopic cylinder (65) and slidably installed with the inner wall of the limiting groove (67). The output end of the roller motor (69) is fixedly installed with the inner side of the connecting frame (64).

3. The tarpaulin raising and rolling device for a truck according to claim 1, wherein: The backup telescopic maintenance mechanism includes a support frame (41) and a scissor-type lifting frame (42). The support frame (41) is fixedly installed on both sides of the front of the sliding frame (4), and the scissor-type lifting frame (42) is fixedly installed on the top of the support frame (41). The top of the scissor-type lifting frame (42) is fixedly installed with the bottom of the maintenance platform (43).

4. The tarpaulin raising and rolling device for a truck according to claim 1, wherein: The lifting drive mechanism includes a winch (51), a wire rope (52), a fixing lug (53), and a pulley (54). The winch (51) is located at the bottom of the back of the truck cab. The pulley (54) is fixedly installed at the center of the bottom of the cross plate (3). One end of the wire rope (52) is fixedly installed with the output end of the winch (51). The other end of the wire rope (52) passes through the pulley (54) from top to bottom and is fixedly installed with the fixing lug (53). The fixing lug (53) is fixedly installed on the top of the back of the sliding frame (4). The roller of the pulley (54) slides in cooperation with the wire rope (52).

5. The tarpaulin raising and rolling device for a truck according to claim 1, wherein: The lifting drive mechanism also includes a lifting motor (501), a second screw (502), and a second screw sleeve block (503). The lifting motor (501) is fixedly installed at the bottom of the longitudinal beam (1), the second screw (502) is fixedly installed at the output end of the lifting motor (501), and the second screw sleeve block (503) is fixedly installed on the side of the sliding frame (4) near the longitudinal beam (1) and is threadedly connected to the second screw (502).

6. The tarpaulin raising and rolling device for a truck according to claim 1, wherein: The lifting drive mechanism also includes a base plate (510), a hydraulic rod (520), and a lifting truss (530). The base plate (510) is fixedly installed at the bottom of the longitudinal beam (1), the hydraulic rod (520) is fixedly installed at the top center of the base plate (510), and the lifting truss (530) is fixedly installed at the top inside the sliding frame (4). The output end of the hydraulic rod (520) is fixedly installed at the bottom of the lifting truss (530).

7. The tarpaulin raising and rolling device for a truck according to claim 3, wherein: The front of the fixed height frame (2) is provided with positioning holes (21), and there are five sets of positioning holes (21). Electromagnetic spring pins (22) are fixedly installed on both sides of the support frame (41), and the electromagnetic spring pins (22) are inserted into the positioning holes (21).

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