Upper roller box structure with automatic overturning function for stretch-bending straightening machine
By designing an automatic flip mechanism on the bending straightener, the problems of complex flip and large footprint of the upper roller box are solved, and efficient and safe online maintenance and roll change operation are achieved.
Patent Information
- Application Number
- CN202410020165.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-07
- Publication Date
- 2025-07-08
AI Technical Summary
The roll box on the existing bending straightener is complicated to flip, requires manual assistance, and covers a large area, which poses safety hazards and affects production efficiency and costs.
An upper roller box structure with automatic flip function is designed, and the online automatic flip of the upper roller box is realized through the automatic flip mechanism on the operation side and the automatic steering mechanism on the transmission side, reducing the intermediate transfer link and manual operation.
The automatic online flip of the upper roller box is realized, which reduces labor intensity and production costs, improves maintenance efficiency, and reduces floor area and safety hazards.
Smart Images
Figure CN120268844A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of metallurgical equipment, and particularly to an upper roll box structure with an automatic flipping function applicable to a tension leveller. Background Art
[0002] In the metallurgical industry, as an important core equipment on the cold rolling line, the tension leveller plays a crucial role in the shape quality of the tension levelled strip. When abnormal conditions such as powder sticking occur on the working roll surface of the roll box and the shape quality of the strip cannot be guaranteed, and it is necessary to maintain or replace the roll system spare parts of the roll box, the roll box is generally pulled out by the roll changing trolley. Since the working surface of the upper roll box faces downward, it is necessary to flip the working roll surface of the upper roll box upward to perform the maintenance and roll changing operations of the roll system of the roll box. However, the upper roll box cannot achieve the online automatic flipping function. Conventional operations require lifting the upper roll box out of the line and placing it on an independent flipping mechanism to flip it by 180 degrees, or the operator transfers the lifted roll box back and forth to manually assist in flipping the upper roll box. The operation steps are complex, the roll changing time is long, and it is also necessary to use a crane to lift it out of the line for operation. When encountering special situations such as the crane not being able to form a quick response and cooperation, if the tension leveller stops for too long, it will inevitably cause certain losses, especially for the continuous galvanizing line, where the downtime cannot be too long. Therefore, the above methods are extremely inconvenient for small repairs, inspections, maintenance, and roll changing operations, with high labor intensity and low efficiency. At the same time, making an independent flipping mechanism outside the line to flip the roll box requires a large floor area, high costs, and increases the intermediate transfer operation link of the roll box, posing safety hazards and being unfavorable for emergency repairs. Summary of the Invention
[0003] To overcome the deficiencies in the maintenance and roll changing operations of the roll box of the existing tension leveller, the invention object of the present invention is to provide an upper roll box structure with automatic flipping for a tension leveller to reduce the intermediate transfer and manual flipping links of the upper roll box and achieve the online automatic flipping of the upper roll box.
[0004] To achieve the above invention object, the automatic flipping mechanism on the operation side installed on the operation side of the upper roll box is connected to the operation side end of the upper roll box through a connecting positioning shaft one and bolts; the automatic steering mechanism on the drive side installed on the drive side of the upper roll box is connected to the drive side end of the upper roll box through a connecting positioning shaft two and bolts; when the upper roll box is inside the main body of the tension leveller, the automatic flipping mechanism on the operation side and the automatic steering mechanism on the drive side are located on both outer sides of the main body of the tension leveller.
[0005] Furthermore, the drive reduction motor of the operating side automatic flipping mechanism is fixed on the flipping frame of the operating side automatic flipping mechanism. The output hole of the drive reduction motor is connected to the output shaft at one end of the worm through a key. Both ends of the worm are respectively equipped with cast steel bearing seats, and the cast steel bearing seats are fixed on the flipping frame. Each of the two cast steel bearing seats at both ends is equipped with a set of spherical roller bearings, inner ring locking nuts, spacer sleeves, and felt ring oil seals. An annular spacer for ensuring the outer ring positioning of the spherical roller bearing on the drive side is installed in the cast steel bearing seat on the drive side; the worm gear is installed on the connecting positioning shaft 1 of the operating side automatic flipping mechanism. The inner hole of the worm gear is connected to the connecting positioning shaft 1 through key positioning. One end face of the worm gear is simultaneously limited by the inner ring positioning sleeve of the deep groove ball bearing 1 in the flipping bearing seat and the deep groove ball bearing 1, and the other end face is locked and limited by the gland and the end face screw of the connecting positioning shaft 1; the flipping bearing seat serving as the flipping operation side fulcrum of the upper roll box is fixed on the flipping frame. Two rows of deep groove ball bearings 1 are installed in the flipping bearing seat. The inner rings of the two rows of deep groove ball bearings 1 are installed on the stepped shaft of the connecting positioning shaft 1 and are concentric with the worm gear. An outer ring positioning spacer ring 1 is provided between the two rows of deep groove ball bearings. The outer ring end face of one row of deep groove ball bearings 1 is positioned by the inner hole step of the flipping bearing seat, and the outer ring end face of the other row of deep groove ball bearings 1 is positioned by the bearing seat gland. The bearing seat gland is locked on one side of the flipping bearing seat by screws.
[0006] Furthermore, two rows of deep groove ball bearings 2 are installed in the inner hole of the bracket of the drive side automatic steering mechanism. The inner rings of the two rows of deep groove ball bearings 2 are installed on the stepped shaft of the connecting positioning shaft 2 of the drive side automatic steering mechanism. An outer ring positioning spacer ring 2 is provided between the two rows of deep groove ball bearings for limiting. The outer ring of one row of deep groove ball bearings 2 is positioned by the inner hole of the bracket, and the outer ring of the other row of deep groove ball bearings 2 is positioned by the bearing gland at the end. The bearing gland is locked and fixed at the end of the bracket by screws. The inner ring of one row of deep groove ball bearings 2 is positioned by the stepped shaft of the connecting positioning shaft 2, and the inner ring of the other row of deep groove balls is positioned by the pressing plate. The pressing plate and the end of the connecting positioning shaft 2 are locked and positioned by screws; Two rows of rollers 1 are installed on the upper part of the bracket to facilitate the roll changing trolley to pull the upper roll box out of the main body of the tension leveller.
[0007] Furthermore, the two rows of rollers 1 on the bracket of the drive side automatic steering mechanism are in rolling cooperation with the roll changing track, and the roll changing track is laid on the frame of the main body of the tension leveller.
[0008] Furthermore, a flange 1 for connecting with the flange plate at the operating side end of the upper roll box is welded on the circumference of the connecting positioning shaft 1; a flange 2 for connecting with the flange plate at the drive side end of the upper roll box is welded on the circumference of the connecting positioning shaft 2.
[0009] Further, a mechanical positioning plate I is installed on the tilting bearing block of the operating side automatic tilting mechanism. The mechanical positioning plate I is provided with a waist-shaped hole. The mechanical positioning plate I is connected and fixed to the tilting bearing block through the waist-shaped hole, and the mechanical positioning plate I is in contact positioning with the boss of the flange at the end of the operating side of the upper roll box; a mechanical positioning plate II is installed on the bracket of the driving side automatic steering mechanism. The mechanical positioning plate II is provided with a waist-shaped hole. The mechanical positioning plate II is connected and fixed to the bracket through the waist-shaped hole, and the mechanical positioning plate II is in contact positioning with the boss of the flange at the end of the driving side of the upper roll box; when the operating side automatic tilting mechanism and the driving side automatic steering mechanism tilt the upper roll box, move the mechanical positioning plate I and the mechanical positioning plate II to separate from the flange at the operating side end and the flange at the driving side end respectively, and the tilting operation of the upper roll box can be realized.
[0010] Further, a pin hole matching with the connecting pin shaft is provided on the tilting frame of the operating side automatic tilting mechanism. The connecting pin shaft can connect the operating side automatic tilting mechanism with the roll changing trolley, and the upper roll box can be automatically and uniformly pulled out of the upper roll box through the roll changing trolley.
[0011] Further, the piston rod end of the oil cylinder of the roll changing trolley is connected to the front end of the vehicle frame. The cylinder barrel of the oil cylinder is fixed on the ground. The bottom of the vehicle frame is equipped with roller II, and the slide rail is laid on the ground. Roller II is in rolling cooperation with the slide rail.
[0012] Compared with the prior art, in the present invention, the upper roll box of the stretcher leveller to be tilted is connected with the roll changing trolley through a pin shaft. The upper roll box that needs to be maintained and the roll changing operation is pulled out of the working position of the stretcher leveller through the roll changing trolley, so that the upper roll box can be automatically and online tilted on the roll changing trolley for maintenance, cleaning, roll changing and other operations, reducing the intermediate link of lifting the upper roll box back and forth, as well as the complex process brought by the offline manual assisted tilting operation. At the same time, there is no need to separately set up an offline roll changing mechanism, saving the on-site space position, with high automation degree, reducing the labor intensity and production cost of the operator, being safe and reliable in operation, and greatly improving the maintenance efficiency. Brief Description of the Drawings
[0013] Figure 1 is the application schematic diagram of the present invention.
[0014] Figure 2 is the structural schematic diagram of the present invention.
[0015] Figure 3 is Figure 2 the structural schematic diagram of the operating side automatic tilting mechanism of
[0016] Figure 4 is Figure 3 the B-B cross-sectional view of
[0017] Figure 5 is Figure 2Schematic diagram of the structure of the automatic steering mechanism on the driving side.
[0018] Figure 6 is Figure 5 A - A sectional view of
[0019] In the figure: 1. Upper roll box; 2. Automatic flipping mechanism on the operating side; 3. Positioning shaft one; 4. Automatic steering mechanism on the driving side; 5. Positioning shaft two; 6. Roller one; 7. Main body of the tension leveller; 8. Connecting pin shaft; 9. Roll changing trolley; 10. Roll changing track; 11. Mechanical positioning plate two; 12. Mechanical positioning plate one; 13. Driving reduction motor; 14. Worm gear; 15. Worm; 16. Flipping frame; 18. Cast steel bearing seat; 19. Spherical roller bearing; 20. Inner ring locking round nut; 21. Sleeve; 22. Felt ring oil seal; 23. Spacer ring; 25. Flipping bearing seat; 26. Inner ring positioning sleeve; 27. Gland; 28. Deep groove ball bearing one; 29. Outer ring positioning spacer ring one; 30. Bearing seat gland; 31. Deep groove ball bearing two; 33. Bearing gland; 34. Pressure plate; 35. Bracket; 36. Flange one; 37. End flange on the operating side; 38. Flange two; 39. End flange on the driving side; 40. Oil cylinder; 41. Roller two; 42. Slide rail; 43. Frame. Detailed implementation manners
[0020] As Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 shown, the automatic flipping mechanism 2 on the operating side of the present invention installed on the operating side of the upper roll box 1 is connected to the operating side end of the upper roll box 1 through the connecting positioning shaft one 3 and bolts; the automatic steering mechanism 4 on the driving side installed on the driving side of the upper roll box 1 is connected to the driving side end of the upper roll box 1 through the connecting positioning shaft two 5 and bolts; when the upper roll box 1 is inside the main body 7 of the tension leveller, the automatic flipping mechanism 2 on the operating side and the automatic steering mechanism 4 on the driving side are located on the outer sides of both sides of the main body 7 of the tension leveller.
[0021] A flange plate one 36 is circumferentially welded to the connecting and positioning shaft one 3 of the operation side automatic flipping mechanism 2; the driving and reducing motor 13 of the operation side automatic flipping mechanism 2 is fixed on the flipping frame 16 of the operation side automatic flipping mechanism 2. The output hole of the driving and reducing motor 13 is key-connected to the output shaft at one end of the worm 15. Cast steel bearing seats 18 are respectively installed at both ends of the worm 15, and the cast steel bearing seats 18 are fixed on the flipping frame 16. A set of self-aligning roller bearings 19, inner ring locking round nuts 20, spacer sleeves 21 and felt ring oil seals 22 are installed in each of the two cast steel bearing seats 18 at both ends. A spacer ring 23 for ensuring the outer ring positioning of the self-aligning roller bearing 19 on the driving side is installed in the cast steel bearing seat 18 on the driving side; the worm gear 14 is installed on the connecting and positioning shaft one 3 of the operation side automatic flipping mechanism 2. The inner hole of the worm gear 14 is key-positioned and connected to the connecting and positioning shaft one 3. One end face of the worm gear 14 is simultaneously limited by the inner ring positioning sleeve 26 of the deep groove ball bearing one 28 in the flipping bearing seat 25 and the deep groove ball bearing one 28, and the other end face is locked and limited by the gland 27 and the end face screw of the connecting and positioning shaft one 3; the flipping bearing seat 25 serving as the flipping operation side fulcrum of the upper roll box is fixed on the flipping frame 16. Two rows of deep groove ball bearings one 28 are installed in the flipping bearing seat 25. The inner rings of the two rows of deep groove ball bearings one 28 are installed on the stepped shaft of the connecting and positioning shaft one 3 and are concentric with the worm gear 14. An outer ring positioning spacer ring one 29 is arranged between the two rows of deep groove balls 28. The outer ring end face of one row of deep groove ball bearings one 28 is positioned by the inner hole step of the flipping bearing seat 25, and the outer ring end face of the other row of deep groove ball bearings one 28 is positioned by the bearing seat gland 30. The bearing seat gland 30 is locked on one side of the flipping bearing seat 25 by screws.
[0022] A flange plate two 38 is circumferentially welded to the connecting and positioning shaft two 5 of the driving side automatic steering mechanism 4; two rows of deep groove ball bearings two 31 are installed in the inner hole of the bracket 35 of the driving side automatic steering mechanism 4. The inner rings of the two rows of deep groove ball bearings two 31 are installed on the stepped shaft of the connecting and positioning shaft two 5 of the driving side automatic steering mechanism 4. An outer ring positioning spacer ring two 32 is arranged between the two rows of deep groove balls 31 for limiting. The outer ring of one row of deep groove ball bearings two 31 is positioned by the inner hole of the bracket 35, and the outer ring of the other row of deep groove ball bearings two 31 is positioned by the bearing gland 33 at the end. The bearing gland 33 is locked and fixed at the end of the bracket 35 by screws. The inner ring of one row of deep groove ball bearings two 31 is positioned by the stepped shaft of the connecting and positioning shaft two 5, and the inner ring of the other row of deep groove balls is positioned by the pressing plate 34. The pressing plate 34 and the end of the connecting and positioning shaft two 5 are locked and positioned by screws; two rows of rollers one 6 are installed on the upper part of the bracket 35 to facilitate the roll changing trolley 9 to pull the upper roll box 1 out of the main body 7 of the stretch-bending straightening machine; the two rows of rollers one 6 on the bracket 35 of the driving side automatic steering mechanism 4 are in rolling fit with the roll changing track 10, and the roll changing track 10 is laid on the frame of the main body 7 of the stretch-bending straightening machine.
[0023] On the overturning bearing block 25 of the operating side automatic overturning mechanism 2, there is a mechanical positioning plate 12. The mechanical positioning plate 12 is provided with a kidney-shaped hole. The mechanical positioning plate 12 is connected and fixed to the overturning bearing block 25 through the kidney-shaped hole. The mechanical positioning plate 12 contacts and positions with the boss of the flange plate 37 at the operating side end of the upper roll box 1. On the bracket 35 of the driving side automatic steering mechanism 4, there is a mechanical positioning plate 11. The mechanical positioning plate 11 is provided with a kidney-shaped hole. The mechanical positioning plate 11 is connected and fixed to the bracket 35 through the kidney-shaped hole. The mechanical positioning plate 11 contacts and positions with the boss of the flange plate 39 at the driving side end of the upper roll box 1. When the operating side automatic overturning mechanism 2 and the driving side automatic steering mechanism 4 overturn the upper roll box 1, move the mechanical positioning plate 12 and the mechanical positioning plate 11 to separate them from the flange plate 37 at the operating side and the flange plate 39 at the driving side respectively, and the overturning operation of the upper roll box 1 can be realized. By setting the mechanical positioning plate 12 and the mechanical positioning plate 11 in the present invention, the operating side automatic overturning mechanism 2 and the driving side automatic steering mechanism 4 can be prevented from being in a free state at both ends of the straightening machine main body 7.
[0024] On the overturning frame 16 of the operating side automatic overturning mechanism 2, there is a pin hole that cooperates with the connecting pin shaft 8. The connecting pin shaft 8 can connect the operating side automatic overturning mechanism 2 with the roll changing trolley 9, and automatically and evenly pull out the upper roll box 1 through the roll changing trolley 9; the piston rod end of the oil cylinder 40 of the roll changing trolley 9 is connected to the front end of the vehicle frame 43. The cylinder barrel of the oil cylinder 40 is fixed on the ground. Two rollers 41 are installed at the bottom of the vehicle frame 43. The slide rail 42 is laid on the ground, and the two rollers 41 are in rolling cooperation with the slide rail 42.
[0025] When it is necessary to pull out the upper roll box 1 from the tension leveller main body 7 for maintenance, repair and roll changing operations, the operator only needs to connect the operating side automatic overturning mechanism 2 of the upper roll box 1 with the roll changing trolley 9 through the connecting pin shaft 8. The roll changing trolley 9 automatically and evenly pulls out the upper roll box 1. The roller 6 installed on the driving side automatic steering mechanism 4 of the upper roll box 1 moves evenly on the roll changing track 10 and stops after reaching the specified position. Then, loosen the bolts on the mechanical positioning plate 12 and the mechanical positioning plate 11 respectively, and move the mechanical positioning plate 12 and the mechanical positioning plate 11 to separate them from the positioning step surfaces of the flange plate 37 at the operating side and the flange plate 39 at the driving side respectively. The driving side automatic steering mechanism 4 is supported on the roll changing track 10 through the roller 6. Drive the transmission reduction motor 13 installed on the operating side automatic overturning mechanism 2, and drive the upper roll box 1 to overturn evenly and stably through the worm gear 14 and the worm 15, and realize the on-line automatic overturning function of the upper roll box 1 on the roll changing trolley 9, so as to carry out maintenance, cleaning and roll changing operations and other work, with high automation degree.
Claims
1. An upper roll box structure with automatic flipping for a stretcher leveller, characterized in that: The automatic flipping mechanism (2) on the operating side installed on the operating side of the upper roll box (1) is connected to the operating side end of the upper roll box (1) through the connecting positioning shaft one (3) and bolts; the automatic steering mechanism (4) on the driving side installed on the driving side of the upper roll box (1) is connected to the driving side end of the upper roll box (1) through the connecting positioning shaft two (5) and bolts; when the upper roll box (1) is inside the main body of the tension leveller (7), the automatic flipping mechanism (2) on the operating side and the automatic steering mechanism (4) on the driving side are located on the outer sides of both sides of the main body of the tension leveller (7).
2. The upper roll box structure with automatic flipping on the stretcher leveller according to claim 1, characterized in that: The drive reduction motor (13) of the automatic flipping mechanism (2) on the operating side is fixed on the flipping frame (16) of the automatic flipping mechanism (2) on the operating side. The output hole of the drive reduction motor (13) is connected to the output shaft at one end of the worm (15) through a key. Cast steel bearing seats (18) are respectively installed at both ends of the worm (15). The cast steel bearing seats (18) are fixed on the flipping frame (16). A set of spherical roller bearings (19), inner ring locking nuts (20), spacer sleeves (21) and felt ring oil seals (22) are respectively installed in the cast steel bearing seats (18) at both ends. A spacer ring (23) for ensuring the outer ring positioning of the spherical roller bearing (19) on the driving side is installed in the cast steel bearing seat (18) on the driving side; the worm gear (14) is installed on the connecting positioning shaft one (3) of the automatic flipping mechanism (2) on the operating side. The inner hole of the worm gear (14) is connected to the connecting positioning shaft one (3) through key positioning. One end face of the worm gear (14) is limited simultaneously with the deep groove ball bearing one (28) through the inner ring positioning sleeve (26) of the deep groove ball bearing one (28) in the flipping bearing seat (25), and the other end face is locked and limited through the gland (27) and the end face screw of the connecting positioning shaft one (3); the flipping bearing seat (25) serving as the fulcrum on the operating side for the flipping of the upper roll box is fixed on the flipping frame (16). Two rows of deep groove ball bearings one (28) are installed in the flipping bearing seat (25). The inner rings of the two rows of deep groove ball bearings one (28) are installed on the stepped shaft of the connecting positioning shaft one (3) and are concentric with the worm gear (14). An outer ring positioning spacer ring one (29) is arranged between the two rows of deep groove balls (28). The outer ring end face of one row of deep groove ball bearings one (28) is positioned through the inner hole step of the flipping bearing seat (25), and the outer ring end face of the other row of deep groove ball bearings one (28) is positioned through the bearing seat gland (30). The bearing seat gland (30) is locked on one side of the flipping bearing seat (25) through screws.
3. The structure of the upper roll box with automatic flipping on the stretcher leveller according to claim 1, wherein: The inner hole of the bracket (35) of the drive-side automatic steering mechanism (4) is equipped with two rows of deep groove ball bearings II (31). The inner rings of the two rows of deep groove ball bearings II (31) are installed on the stepped shaft of the connecting and positioning shaft II (5) of the drive-side automatic steering mechanism (4). An outer ring positioning spacer ring II (32) is provided for limiting between the two rows of deep groove balls (31). The outer ring of one row of deep groove ball bearings II (31) is positioned through the inner hole of the bracket (35), and the outer ring of the other row of deep groove ball bearings II (31) is positioned through the bearing gland (33) at the end. The bearing gland (33) is fixed to the end of the bracket (35) by screwing. The inner ring of one row of deep groove ball bearings II (31) is positioned through the stepped shaft of the connecting and positioning shaft II (5), and the inner ring of the other row of deep groove balls is positioned through the pressing plate (34). The pressing plate (34) and the end of the connecting and positioning shaft II (5) are locked and positioned by screws; two rows of rollers I (6) are installed on the upper part of the bracket (35) to facilitate the roll-changing trolley (9) to pull the upper roll box (1) out of the main body (7) of the stretch-bending straightening machine.
4. The upper roll box structure with automatic flipping for a stretch leveling machine according to claim 1, characterized in that: The two rows of rollers I (6) on the bracket (35) of the drive-side automatic steering mechanism (4) are in rolling cooperation with the roll-changing track (10), and the roll-changing track (10) is laid on the frame of the main body (7) of the stretch-bending straightening machine.
5. The upper roll box structure with automatic flipping on a stretcher leveller according to claim 1, characterized in that: A flange I (36) for connecting with the flange plate (37) at the operating side end of the upper roll box (1) is welded to the circumference of the connecting and positioning shaft I (3); a flange II (38) for connecting with the flange plate (39) at the drive-side end of the upper roll box (1) is welded to the circumference of the connecting and positioning shaft II (5).
6. The structure of the upper roll box with automatic flipping on the stretcher leveller according to claim 1, characterized in that: A mechanical positioning plate I (12) is installed on the overturning bearing seat (25) of the operating-side automatic overturning mechanism (2). The mechanical positioning plate I (12) is provided with a waist-shaped hole, and the mechanical positioning plate I (12) is connected and fixed to the overturning bearing seat (25) through the waist-shaped hole. The mechanical positioning plate I (12) is in contact positioning with the boss of the flange plate (37) at the operating side end of the upper roll box (1); a mechanical positioning plate II (11) is installed on the bracket (35) of the drive-side automatic steering mechanism (4). The mechanical positioning plate II (11) is provided with a waist-shaped hole, and the mechanical positioning plate II (11) is connected and fixed to the bracket (35) through the waist-shaped hole. The mechanical positioning plate II (11) is in contact positioning with the boss of the flange plate (39) at the drive-side end of the upper roll box (1); when the operating-side automatic overturning mechanism (2) and the drive-side automatic steering mechanism (4) overturn the upper roll box (1), the mechanical positioning plate I (12) and the mechanical positioning plate II (11) are moved to be separated from the flange plate (37) at the operating side end and the flange plate (39) at the drive-side end respectively.
7. The upper roll box structure with automatic flipping on the stretch leveling machine according to claim 1, characterized in that: A pin hole matching with the connecting pin shaft (8) is provided on the overturning frame (16) of the operating-side automatic overturning mechanism (2). The connecting pin shaft (8) can connect the operating-side automatic overturning mechanism (2) with the roll-changing trolley (9), and the upper roll box (1) can be automatically and uniformly pulled out of the upper roll box (1) through the roll-changing trolley (9).
8. The upper roll box structure with automatic flipping for a stretcher leveler according to claim 3, characterized in that: The piston rod end of the oil cylinder (40) of the roll changing trolley (9) is connected to the front end of the vehicle frame (43), the cylinder barrel of the oil cylinder (40) is fixed on the ground, roller two (41) is installed at the bottom of the vehicle frame (43), the slide rail (42) is laid on the ground, and roller two (41) is in rolling fit with the slide rail (42).