Rigid contact net trackless measurement auxiliary equipment

Abstract

The invention discloses a rigid catenary trackless measurement auxiliary device, and relates to the technical field of rigid catenary construction.The rigid catenary trackless measurement auxiliary device comprises a bottom plate, the upper surface of the bottom plate is rotationally connected with an adjusting screw rod, and the outer side of the adjusting screw rod is in threaded connection with an adjusting plate; the upper surface of the adjusting plate is fixedly connected with a gradienter used for observing whether the adjusting plate is in a horizontal state or not, a measuring equipment plate is placed on the upper surface of the adjusting plate, and a limiting cylinder is arranged on the lower surface of the adjusting plate. According to the rigid contact net trackless measurement auxiliary equipment, the center of the bottom plate is aligned with the center line of a subway track line, the movable frame is adjusted to abut against the two sides of the track, auxiliary limiting can be conducted on the equipment, the space reference of the track is simulated, and a stable measurement reference is provided for a laser measuring instrument, a total station and other equipment; the problem of benchmark missing in trackless measurement is solved, measured data are matched with actual track parameters, and it is ensured that the position of a suspension point of the overhead line system is accurate.

Description

Technical Field

[0001] The invention relates to the technical field of rigid contact network construction, in particular to a rigid contact network trackless measurement auxiliary device. Background Art

[0002] The rigid catenary is a key system used to supply power to trains in rail transit (such as subways and light rail). It directly provides power to the pantograph through a fixed suspended conductive device. Trackless measurement of the rigid catenary is a technology that accurately measures various parameters of the rigid catenary without relying on fixed measurement benchmarks such as tracks. During trackless measurement, the track is not laid or is unstable, resulting in a lack of reference for measurement and difficulty in locating the suspension point.

[0003] Prior art 1 (a Chinese patent with announcement number CN112444230B and announcement date 2022-02-15) is a trackless measurement method for the bottom plate angle of a rigid contact network tunnel suspender, which belongs to the technical field of rigid contact network construction in urban rail transit, and includes the following steps: step 1, preparing a measuring tool; step 2, projecting a positioning point; step 3, measuring the bottom plate angle of the suspender at the positioning point; step 4, compiling a rigid contact network suspender construction table, and determining the bottom plate angle of the rigid contact network tunnel suspender in a trackless state. The measuring tool is simple and lightweight, and one person can complete the entire measurement process, saving costs. The measuring method is easy to understand, efficient and accurate, and is less disturbed by cross-construction during the trackless construction process, thereby achieving good economic and social benefits. There is also prior art 2 (announcement number CN219223644U and announcement date (Chinese Patent No. 2023-06-20) A rigid contact network trackless measurement auxiliary device comprises two brackets, a fixed frame is fixedly connected between the middle parts of the two brackets, movable rods are slidably connected on the left and right sides of the two brackets, a screw is threadedly connected to the side of the movable rod close to the fixed frame, and the end of the screw away from the fixed frame is rotatably connected to a limit block, and a rotating shaft is provided inside the fixed frame. Through the cooperation of the rotating shaft, the driving gear, the driven gear, the screw, the movable rod and the limit block, the rigid contact network trackless measurement auxiliary device can adapt to tunnels of different widths, thereby improving the applicability of the device; through the cooperation of the bracket, the screw, the handwheel, the ball, the telescopic rod, the placement plate and the bubble level, the rigid contact network trackless measurement auxiliary device can ensure that the measuring device thereon is in a horizontal state, thereby improving the measurement accuracy.

[0004] Although the existing technology can ensure that the measuring device is in a horizontal state and improve the measurement accuracy, the measuring device cannot be further limited and fixed after it is placed. When the measuring device is placed unstably, the laser measuring equipment placed above it may fall over and be damaged, which poses a certain risk.

[0005] Therefore, we proposed a rigid contact network trackless measurement auxiliary equipment to solve the problems raised above. Summary of the Invention

[0006] The purpose of the present invention is to provide a rigid contact network trackless measurement auxiliary equipment to solve the problem raised in the above background technology that the measuring device currently on the market cannot be further limited and fixed after it is placed. When the measuring device is placed unstably, the laser measuring equipment placed above it may fall over and be damaged, which poses a certain risk.

[0007] 7. The swiftly and minutely adjusting device for a wood-planer working table as claimed in claim 1, wherein said adjusting base is connected to said adjusting base by said adjusting base, and said adjusting base is connected to said adjusting base by said adjusting base. said adjusting base is connected to said platform by said adjusting base. said adjusting base is a centering plate of said second adjusting base. said adjusting base is a centering plate of said second adjusting base.

[0008] Preferably, the auxiliary fixing mechanism includes an air suction box, which is fixedly connected to the lower surface of the adjustment plate, and a suction cup is provided through the center of the adjustment plate, and a connecting groove that is connected to the interior of the air suction box is opened inside the suction cup, and at the same time, the upper surface of the suction cup is adsorbed with the lower surface of the placed measuring equipment plate.

[0009] Preferably, the upper surface of the base plate is fixedly connected to a fixing rod which is slidably connected to the air suction box, and the upper end of the fixing rod is arranged inside the air suction box, and the upper end of the fixing rod is fixedly connected to the air suction plate, and the air suction plate is slidably connected to the inside of the air suction box.

[0010] Preferably, the adjusting mechanism includes a motor, which is fixedly connected to the center of the lower surface of the adjusting plate, and the output ends on both sides of the motor are fixedly connected to auxiliary screws, and the auxiliary screws are rotatably arranged inside the limiting cylinder, and the movable frame is slidably connected to the inside of the limiting cylinder, and the inner side of the movable frame is threadedly connected to the auxiliary screw, and the outer end of the movable frame can slide through the outer end of the limiting cylinder.

[0011] Preferably, the outer end of the movable frame is fixedly connected to a fixed box, and the interior of the fixed box is slidably connected to a support block for improving the placement stability of the equipment, the side of the fixed box is slidably provided with a connecting block, and the inner side of the connecting block is fixedly connected to the support block, and the outer side of the connecting block is hingedly provided with a second rotating rod.

[0012] Preferably, a rotating shaft is rotatably connected to the upper portion of the fixed box, and a first rotating rod is fixedly connected to the outer end of the rotating shaft, and an end of the first rotating rod away from the rotating shaft and an end of the second rotating rod away from the connecting block are hinged to each other.

[0013] Preferably, the interference mechanism includes a first airbag, which is fixedly connected to the upper surface of the adjustment plate, and the upper surface of the adjustment plate is fixedly connected to a fixed plate, and a linkage shaft is rotatably connected between the two groups of fixed plates, and a clamping plate is fixedly connected to the linkage shaft to assist in pressing the side of the measuring equipment plate.

[0014] Preferably, a connecting plate is fixedly connected to the outer side of the connecting block, and a pressure plate is fixedly connected to the end side of the connecting plate, and when the movable frame is in the expanded state, the pressure plate is located above the first airbag.

[0015] Preferably, a limiting groove is provided inside the fixed plate, and the limiting groove is arranged in an arc-shaped structure. A resistance rod is fixedly connected to the outer side of the linkage shaft, and the resistance rod is slidably connected inside the limiting groove. A second airbag is fixedly connected between the side of the resistance rod and the inner side of the limiting groove, and the second airbag is connected to the first airbag through a connecting pipe.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) Align the center of the base plate with the center line of the subway track. By adjusting the mobile frame to make it touch both sides of the track, the equipment itself can be assisted in limiting, simulating the spatial reference of the track, providing a stable measurement reference for equipment such as laser measuring instruments and total stations, solving the problem of missing reference in trackless measurement, matching the measurement data with the actual track parameters, and ensuring the accurate position of the contact network suspension point.

[0017] (2) The height of the adjustment plate can be adjusted by turning the adjustment screw to simulate the height of the track itself. By observing the indication of the level meter, it can be confirmed that the adjustment plate is completely in a horizontal position after adjustment, thereby ensuring that the measuring equipment plate it carries reaches a horizontal state at the same time, avoiding measurement deviation caused by the tilt of the device.

[0018] (3) The measuring device plate can be adsorbed by the suction cup, which preliminarily ensures the stability of the placement of the measuring device plate. When the operator moves the adjustment plate up in the vertical direction, the contact area between the suction cup and the measuring device plate can form a negative pressure seal, thereby enhancing the adsorption force of the suction cup and further improving the stability of the placement of the measuring device plate.

[0019] (4) After the position adjustment of the mobile frame is completed, the operator manually rotates the shaft, which can make the connecting block synchronously drive the support block to slide linearly until the bottom surface of the support block forms a rigid contact with the ground, building a stable anti-slip support system and effectively reducing the displacement risk of the equipment during measurement operations.

[0020] (5) The connecting plate drives the pressure plate to press the first airbag, causing gas exchange between the first airbag and the second airbag, driving the second airbag to expand. After the second airbag expands, the linkage shaft drives the card plate to rotate and resist the side of the measuring device plate, thereby further limiting the position of the measuring device plate and ensuring the stability of the placement of the measuring device plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a three-dimensional schematic diagram of the structure of the present invention in an expanded state; Figure 2 This is a schematic diagram of a three-dimensional cross-sectional structure of the limiting cylinder in the undeployed state of the present invention; Figure 3 This is a schematic diagram of the three-dimensional cross-sectional structure of the air suction box of the present invention; Figure 4 For the present invention Figure 3 A in the middle is an enlarged structural diagram; Figure 5 This is a schematic diagram of the three-dimensional structure of the fixing box of the present invention; Figure 6 This is a schematic diagram of a three-dimensional cross-sectional structure of a fixing box of the present invention; Figure 7 This is a schematic diagram of the three-dimensional structure of the second rotating rod of the present invention; Figure 8 This is a schematic diagram of the three-dimensional structure of the first airbag of the present invention; Figure 9 It is a schematic diagram of the three-dimensional cross-sectional structure of the fixing plate of the present invention.

[0022] In the figure: 1. Base plate; 2. Adjusting screw; 3. Motor; 4. Moving frame; 5. Limiting cylinder; 6. Auxiliary screw; 7. Fixing box; 8. Measuring device plate; 9. Suction box; 10. Suction cup; 11. Connecting groove; 12. First air bag; 13. Second air bag; 14. Connecting pipe; 15. Limiting groove; 16. Resistance rod; 17. Clamping plate; 18. Adjusting plate; 19. Pressing plate; 20. Connecting plate; 21. Level; 22. Fixing rod; 23. Suction plate; 24. Rotating shaft; 25. First rotating rod; 26. Second rotating rod; 27. Support block; 28. Connecting block; 29. ​​Fixing plate; 30. Linkage shaft. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] Example 1: Figure 1 、 Figure 2 、 Figure 5-Figure 7 The technical solution shown in the figure, the present invention provides the following technical solution: a rigid contact network trackless measurement auxiliary equipment, disclosing an adjustment mechanism, through which the mobile frame 4 can be moved laterally to simulate the lateral geometric state of the track, the upper surface of the base plate 1 is rotatably connected to the adjustment screw 2, and the outer side of the adjustment screw 2 is threadedly connected to the adjustment plate 18, and the upper surface of the adjustment plate 18 is fixedly connected to a spirit level 21 for observing whether the adjustment plate 18 is in a horizontal state, the lower surface of the adjustment plate 18 is provided with a limit cylinder 5, and the interior of the limit cylinder 5 is provided with an adjustment mechanism for laterally limiting and fixing the equipment, the adjustment mechanism simulates the lateral geometric state of the track through the lateral movement of the mobile frame 4 it contains (the simulated lateral geometric state refers to the offset of the simulated track in the horizontal direction relative to the design center line. In the construction of the rigid contact network, the lateral position of the simulated track must be strictly controlled within the error range allowed by the design to ensure good contact and stable current collection between the contact network and the pantograph) The adjusting mechanism includes a motor 3, which is fixedly connected to the center of the lower surface of the adjusting plate 18, and the output ends on both sides of the motor 3 are fixedly connected to auxiliary screws 6. At the same time, the auxiliary screws 6 are rotatably arranged inside the limiting cylinder 5, and the mobile frame 4 is slidably connected to the inside of the limiting cylinder 5, and the inner side of the mobile frame 4 is threadedly connected to the auxiliary screws 6, and the outer end of the mobile frame 4 can slide through the outer end of the limiting cylinder 5. The outer end of the mobile frame 4 is fixedly connected to a fixed box 7, and the inner side of the fixed box 7 is slidably connected to a support block 27 for improving the placement stability of the equipment. A connecting block 28 is slidingly provided on the side of the fixed box 7, and the inner side of the connecting block 28 is fixedly connected to the support block 27, and the outer side of the connecting block 28 is hingedly provided with a second rotating rod 26. The top of the fixed box 7 is rotatably connected to a rotating shaft 24, and the outer end of the rotating shaft 24 is fixedly connected to a first rotating rod 25, and the end of the first rotating rod 25 away from the rotating shaft 24 and the end of the second rotating rod 26 away from the connecting block 28 are hinged to each other.

[0025] Align the center of the bottom plate 1 with the center line of the subway track line. After placement, start the motor 3, which can drive the auxiliary screws 6 on both sides to rotate. When the auxiliary screws 6 are rotating, the mobile frame 4 can slide outward along the inside of the limit cylinder 5 under the action of the threaded connection and the limiting action of the limit cylinder 5, adjust the position of the mobile frame 4 to make it contact both sides of the track, and perform auxiliary limiting on the equipment itself, simulate the spatial reference of the track, provide a stable measurement reference for equipment such as laser measuring instruments and total stations, solve the problem of missing reference in trackless measurement, match the measurement data with the actual track parameters, and ensure connection. The position of the contact network suspension point is accurate. After the position adjustment of the mobile frame 4 is completed, the operator manually rotates the rotating shaft 24 to drive the first rotating rod 25 to rotate around the rotating shaft 24. When the first rotating rod 25 is rotating, the first rotating rod 25 drives the second rotating rod 26 to produce planar motion through the hinge mechanism. The end of the second rotating rod 26 pushes the connecting block 28 downward in the vertical direction. The connecting block 28 synchronously drives the support block 27 to slide linearly in the guide groove of the fixed box 7 through a rigid connection until the bottom surface of the support block 27 forms a rigid contact with the ground, thereby constructing a stable anti-slip support system and effectively reducing the displacement risk of the equipment during measurement operations.

[0026] Example 2: Figure 3 and Figure 4 The technical solution shown in the figure, the present invention provides the following technical solutions: a rigid contact network trackless measurement auxiliary device, discloses an auxiliary fixing mechanism, the auxiliary fixing mechanism can enhance the adsorption force of the suction cup 10, further improve the stability of the placement of the measuring device plate 8, the measuring device plate 8 is placed on the upper surface of the adjustment plate 18, and an auxiliary fixing mechanism is provided between the inside of the adjustment plate 18 and the upper surface of the bottom plate 1, the auxiliary fixing mechanism realizes the adsorption limit of the measuring device plate 8 by the movement of the adjustment plate 18, the auxiliary fixing mechanism includes an air suction box 9, the air suction box 9 is fixed It is fixedly connected to the lower surface of the adjustment plate 18, and a suction cup 10 is provided at the center of the adjustment plate 18, and a connecting groove 11 is provided inside the suction cup 10 which is connected to the inside of the suction box 9. At the same time, the upper surface of the suction cup 10 is adsorbed on the lower surface of the placed measuring equipment plate 8. The upper surface of the base plate 1 is fixedly connected to a fixing rod 22 which is slidably connected to the suction box 9, and the upper end of the fixing rod 22 is provided inside the suction box 9, and the upper end of the fixing rod 22 is fixedly connected to the suction plate 23, and the suction plate 23 is slidably connected to the inside of the suction box 9.

[0027] After the equipment position adjustment is completed, the adjusting screw 2 can be rotated. At this time, the adjusting plate 18 moves up under the threaded connection of the adjusting screw 2, and the height of the adjusting screw 2 is adjusted to simulate the height of the track itself. The operator needs to observe the indication status of the level meter 21 in real time to confirm that the adjusting plate 18 is completely in a horizontal position after adjustment, thereby ensuring that the measuring equipment plate 8 it carries reaches a horizontal state synchronously, avoiding measurement deviation caused by the tilt of the device. When the measuring equipment plate 8 is placed on the adjusting plate 18, the suction cup 10 provided above the adjusting plate 18 can adsorb the lower surface of the measuring equipment plate 8, thereby preliminarily To ensure the stability of the placement of the measuring equipment plate 8, when the operator adjusts the adjustment plate 18 to move up in the vertical direction, the adjustment plate 18 synchronously drives the suction box 9 assembled below it to slide along the fixed rod 22. At this time, the suction plate 23 fixed inside the suction box 9 remains stationary, and the gas in the box is continuously sucked through the negative pressure chamber formed above the suction plate 23 to form a dynamic negative pressure environment. The negative pressure is transmitted to the adsorption surface of the suction cup 10 through the connecting groove 11, so that the contact area between the suction cup 10 and the measuring equipment plate 8 forms a negative pressure seal, thereby enhancing the adsorption force of the suction cup 10 and further improving the stability of the placement of the measuring equipment plate 8.

[0028] Example 3: Figure 1 、 Figure 8 and Figure 9 The technical solution shown in the figure, the present invention provides the following technical solutions: a rigid contact network trackless measurement auxiliary equipment discloses a resistance mechanism, through which the measurement equipment plate 8 can be further limited to ensure the stability of the placement of the measurement equipment plate 8: the upper surface of the adjustment plate 18 is provided with a resistance mechanism, and the operation of the adjustment mechanism drives the card plate 17 provided inside the resistance mechanism to rotate, thereby realizing further limiting the measurement equipment plate 8, and the resistance mechanism includes a first airbag 12, the first airbag 12 is fixedly connected to the upper surface of the adjustment plate 18, the upper surface of the adjustment plate 18 is fixedly connected to a fixed plate 29, and a linkage shaft 30 is rotatably connected between the two sets of fixed plates 29, and the linkage shaft 30 A clamping plate 17 for assisting in pressing the side of the measuring equipment plate 8 is fixedly connected to the upper portion, a connecting plate 20 is fixedly connected to the outer side of the connecting block 28, and a pressure plate 19 is fixedly connected to the end side of the connecting plate 20, and when the movable frame 4 is in the expanded state, the pressure plate 19 is located above the first airbag 12, a limiting groove 15 is provided inside the fixed plate 29, and the limiting groove 15 is arranged in an arc-shaped structure, a resistance rod 16 is fixedly connected to the outer side of the linkage shaft 30, and the resistance rod 16 is slidably connected to the inside of the limiting groove 15, and a second airbag 13 is fixedly connected between the side of the resistance rod 16 and the inner side of the limiting groove 15, and the second airbag 13 is connected to the first airbag 12 through a connecting pipe 14.

[0029] During the downward movement of the connecting block 28, it will synchronously drive the pressure plate 19 through the connecting plate 20 to vertically press the first airbag 12, causing it to undergo controllable elastic deformation. The deformed first airbag 12 can transport the gas stored inside to the inside of the second airbag 13 through the connecting pipe 14, driving the second airbag 13 to expand. The expanded second airbag 13 can push the interference rod 16 to rotate along the limiting groove 15 opened in the arc structure. The rotating interference rod 16 can synchronously drive the linkage shaft 30 to rotate. At this time, the linkage shaft 30 can synchronously drive the card plate 17 to rotate. The rotated card plate 17 can resist the side of the measuring device plate 8 and further limit the measuring device plate 8 to ensure the stability of the placement of the measuring device plate 8.

[0030] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A rigid contact network trackless measurement auxiliary device, comprising a base plate (1), an upper surface of the base plate (1) being rotatably connected to an adjusting screw (2), an outer side of the adjusting screw (2) being threadedly connected to an adjusting plate (18), and an upper surface of the adjusting plate (18) being fixedly connected to a level (21) for observing whether the adjusting plate (18) is in a horizontal state, characterized in that: A measuring device plate (8) is placed on the upper surface of the adjusting plate (18), and an auxiliary fixing mechanism is provided between the inside of the adjusting plate (18) and the upper surface of the bottom plate (1). The auxiliary fixing mechanism realizes adsorption and positioning of the measuring device plate (8) by the movement of the adjusting plate (18). A limiting cylinder (5) is provided on the lower surface of the adjusting plate (18), and an adjusting mechanism for lateral positioning and positioning of the device is provided inside the limiting cylinder (5). The adjusting mechanism simulates the lateral geometric state of the track through the lateral movement of the movable frame (4) contained therein. At the same time, a resistance mechanism is provided on the upper surface of the adjusting plate (18). The operation of the adjusting mechanism drives the card plate (17) provided inside the resistance mechanism to rotate, thereby realizing further positioning of the measuring device plate (8).

2. The rigid contact network trackless measurement auxiliary equipment according to claim 1, characterized in that: The auxiliary fixing mechanism includes an air suction box (9), which is fixedly connected to the lower surface of the adjustment plate (18), and a suction cup (10) is provided at the center of the adjustment plate (18), and a connecting groove (11) is provided inside the suction cup (10) and is connected to the inside of the air suction box (9). At the same time, the upper surface of the suction cup (10) is adsorbed with the lower surface of the placed measuring device plate (8).

3. The rigid contact network trackless measurement auxiliary equipment according to claim 2, characterized in that: A fixing rod (22) is fixedly connected to the upper surface of the base plate (1) and is slidably connected to the air suction box (9). The upper end of the fixing rod (22) is arranged inside the air suction box (9). The upper end of the fixing rod (22) is fixedly connected to the air suction plate (23), and the air suction plate (23) is slidably connected to the inside of the air suction box (9).

4. The rigid catenary trackless measurement auxiliary device according to claim 1, characterized in that: The adjustment mechanism includes a motor (3), the motor (3) is fixedly connected to the center of the lower surface of the adjustment plate (18), and the output ends on both sides of the motor (3) are fixedly connected to auxiliary screws (6), and the auxiliary screws (6) are rotatably arranged inside the limiting cylinder (5), and the moving frame (4) is slidably connected to the inside of the limiting cylinder (5), and the inner side of the moving frame (4) is threadedly connected to the auxiliary screws (6), and the outer end of the moving frame (4) can slide through the outer end of the limiting cylinder (5).

5. The rigid catenary trackless measurement auxiliary equipment according to claim 4, characterized in that: The outer end of the movable frame (4) is fixedly connected to a fixed box (7), and the interior of the fixed box (7) is slidably connected to a support block (27) for improving the placement stability of the device. A connecting block (28) is slidably provided on the side of the fixed box (7), and the inner side of the connecting block (28) is fixedly connected to the support block (27), and the outer side of the connecting block (28) is hingedly provided with a second rotating rod (26).

6. The rigid catenary trackless measurement auxiliary equipment according to claim 5, characterized in that: A rotating shaft (24) is rotatably connected to the upper portion of the fixed box (7), and a first rotating rod (25) is fixedly connected to the outer end of the rotating shaft (24), and an end of the first rotating rod (25) away from the rotating shaft (24) and an end of the second rotating rod (26) away from the connecting block (28) are hinged to each other.

7. The rigid catenary trackless measurement auxiliary equipment according to claim 6, characterized in that: The interference mechanism includes a first airbag (12), the first airbag (12) is fixedly connected to the upper surface of the adjustment plate (18), the upper surface of the adjustment plate (18) is fixedly connected to a fixing plate (29), and a linkage shaft (30) is rotatably connected between the two sets of fixing plates (29), and a clamping plate (17) for assisting in pressing the side of the measuring device plate (8) is fixedly connected to the linkage shaft (30).

8. The rigid catenary trackless measurement auxiliary equipment according to claim 7, characterized in that: The outer side of the connecting block (28) is fixedly connected to a connecting plate (20), and the end side of the connecting plate (20) is fixedly connected to a pressing plate (19), and when the movable frame (4) is in the unfolded state, the pressing plate (19) is located above the first airbag (12).

9. The rigid catenary trackless measurement auxiliary equipment according to claim 8, characterized in that: A limiting groove (15) is provided inside the fixing plate (29), and the limiting groove (15) is arranged in an arc-shaped structure. The outer side of the linkage shaft (30) is fixedly connected to a resistance rod (16), and the resistance rod (16) is slidably connected to the inner side of the limiting groove (15). A second airbag (13) is fixedly connected between the side of the resistance rod (16) and the inner side of the limiting groove (15), and the second airbag (13) is connected to the first airbag (12) through a connecting pipe (14).

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