An intelligent warehousing equipment for air freight containers with an automatic locking mechanism

Abstract

The present invention discloses an intelligent warehousing equipment for air freight containers with an automatic locking and clamping mechanism, which relates to the technical field of transfer devices. The intelligent warehousing equipment for air freight containers with an automatic locking and clamping mechanism includes a second crossbeam frame, a first transfer component, a second transfer component and a fixing component; the first transfer component is arranged on the second crossbeam frame, the first transfer component includes a second transmission device and two guiding members, the second transfer component is arranged under the second crossbeam frame, the second transfer component includes a first pulley, a towing rope, a first transmission device, a base, a first crossbeam frame and a guiding base. By arranging the first transfer component and the second transfer component, the second transmission device of the first transfer component on the right side can transfer the aviation box to the second transfer component. Subsequently, the second transfer component drives the aviation box to move to a suitable position, and then, in cooperation with the first transfer component, the aviation box is placed at a suitable position. The whole process does not require manual handling, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of transfer devices, and particularly to an intelligent warehousing equipment for air freight containers with an automatic locking and clamping mechanism. Background Art

[0002] The intelligent warehousing equipment for air freight containers is an important part of modern logistics warehousing systems, aiming to improve warehousing efficiency, reduce manual intervention, ensure the safety of air containers, and optimize the utilization of warehousing space.

[0003] With the progress of modernization, its storage requirements for air containers have become more refined, targeted, and customized with the advancement of technology to improve the efficiency of retrieving air containers. To adapt to the retrieval and storage of different air containers, the original warehouse uses shelves, and workers manually place the air containers on the shelves. The goods on the shelves need to be counted manually before they can be retrieved, which is rather troublesome. Therefore, there is an urgent need for an intelligent warehousing equipment for air freight containers with an automatic locking and clamping mechanism that can store air containers according to the information of the air containers, and when retrieving air containers, there is no need for manual handling of the air containers, reducing the working intensity of air container transfer. After storing the air containers, not only is manual retrieval required, but the air containers also need to be counted regularly, resulting in a relatively high working intensity for the workers. Summary of the Invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art, and provide an intelligent warehousing equipment for air freight containers with an automatic locking and clamping mechanism, which can solve the problem that after storing air containers, not only is manual retrieval required, but the air containers also need to be counted regularly, resulting in a relatively high working intensity for the workers.

[0005] To achieve the above purpose, the present invention provides the following technical solution: an intelligent warehousing equipment for air freight containers with an automatic locking and clamping mechanism, including a second crossbeam frame, a first transfer assembly, a second transfer assembly, and a fixing assembly;

[0006] The first transfer assembly is arranged on the second crossbeam frame. The first transfer assembly includes a second transmission device and two guide members. The second transmission device is installed on the second crossbeam frame, and both guide members are fixed on the second crossbeam frame. The two guide members are respectively arranged on both sides of the upper end of the second transmission device. The number of the first transfer assemblies is multiple, and multiple first transfer assemblies are all arranged on the second crossbeam frame;

[0007] The second transfer assembly is arranged under the second crossbeam frame. The second transfer assembly includes a first pulley, a towing rope, a first transmission device, a base, a first crossbeam frame, and a guide base. The base is arranged at the lower end of the second crossbeam frame. The first crossbeam frame is welded to the upper end of the base. The guide base slides along the surface of the first crossbeam frame. The first transmission device is installed on the guide base;

[0008] The fixing components are arranged on the second crossbeam frame. The fixing components include two fixing pieces, two compression springs, two guide rods and compression rods. Both of the two guide rods slide through the crossbeam on the second crossbeam frame. The two fixing pieces are respectively fixed at the lower ends of the corresponding guide rods. The number of the fixing components is multiple, and multiple fixing components are all arranged on the second crossbeam frame.

[0009] Preferably, the second pulley is installed on the left side of the first crossbeam frame, and the first pulley is installed on the right side of the first crossbeam frame.

[0010] Preferably, a first motor is installed on the right support of the first crossbeam frame. The output end of the first motor is connected to the towing rope. The towing rope passes through the first pulley, the second pulley and is connected to the upper end of the guiding base.

[0011] Preferably, an air cargo container is conveyed on the upper end of the first transmission device, and an identical air cargo container is conveyed on the upper end of the second transmission device.

[0012] Preferably, a plurality of rollers are installed on the surface of the base. A second motor is installed on one side of the base. The second motor is electrically connected to the plurality of rollers.

[0013] Preferably, the second transfer component is arranged between a plurality of first transfer components. A trailer is arranged outside the second crossbeam frame.

[0014] Preferably, a plurality of the compression rods are all installed on the crossbeam of the second crossbeam frame. Two ends of a plurality of compression rods are respectively connected to the corresponding compression springs.

[0015] Preferably, the upper ends of a plurality of the compression springs are fixedly connected to the crossbeam of the second crossbeam frame, and the lower ends of a plurality of the compression springs are respectively fixedly connected to the upper ends of the corresponding fixing pieces.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. For the intelligent warehousing equipment for air cargo containers with an automatic locking mechanism, by arranging the first transfer component and the second transfer component, the second transmission device of the first transfer component on the right side can transfer the air cargo container to the second transfer component. Subsequently, the second transfer component drives the air cargo container to move to a suitable position, and then, in cooperation with the first transfer component, places the air cargo container in a suitable position. The whole process does not require manual handling, etc. Moreover, since the transfer positions can be stored in the cloud, there is no need for manual inventory of air cargo containers, thereby reducing subsequent work and saving manpower.

[0018] 2. For the intelligent warehousing equipment for air cargo containers with an automatic locking mechanism, by arranging the second transfer component, the first motor in the second transfer component can drive the guiding base to a suitable height, so as to lift and lower the air cargo container, eliminating the need for workers to lift, etc., thereby greatly reducing the working intensity of workers.

[0019] 3. The intelligent warehousing equipment for air freight containers with an automatic locking and clamping mechanism can fix its air freight container on the second transmission device through the fixed component, avoiding the accident of the air freight container falling off due to shaking with the second crossbeam when other air freight containers are placed, that is, ensuring the safety of the air freight container.

[0020] 4. The intelligent warehousing equipment for air freight containers with an automatic locking and clamping mechanism can guide its air freight container through the guiding parts in the second transfer component. The two guiding parts can guide the air freight container to avoid the deviation of the air freight container when it is driven by the second transmission device, that is, ensuring the certainty of the position of the air freight container during the whole transfer process, so as to better carry out the transfer work of the air freight container. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below in conjunction with the drawings and embodiments:

[0022] Figure 1 It is a schematic side view of the overall structure of the present invention;

[0023] Figure 2 It is a schematic diagram of the overall components on the first crossbeam of the present invention;

[0024] Figure 3 It is a schematic diagram of the overall unit of the second crossbeam of the present invention;

[0025] Figure 4 It is a schematic diagram of the pressing state of the pressing mechanism of the present invention;

[0026] Figure 5 It is a schematic diagram of the unlocking state of the pressing mechanism of the present invention;

[0027] Figure 6 It is a schematic diagram of the structure of the pressing mechanism of the present invention.

[0028] Reference numerals: 1, air freight container; 2, trailer; 3, first pulley; 4, towing rope; 5, first motor; 6, first transmission device; 7, second motor; 8, roller; 9, base; 10, first crossbeam; 11, guiding base; 12, second pulley; 13, guiding part; 14, second transmission device; 15, second crossbeam; 16, fixing part; 17, pressing spring; 18, guiding rod; 19, pressing rod; 20, pressing mechanism; 21, motor and gear mechanism; 22, rack and push rod mechanism; 23, support of push rod mechanism; 24, V-shaped concave head; 25, automatic return spring; 26, wedge block; 27, stacker; 28, stacker car; 29, travel-in-place detection switch; 30, travel-in-place stop block. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The function of the accompanying drawings is to supplement the description in the text part of the specification, enabling people to intuitively and vividly understand each technical feature and the overall technical solution of the present invention. However, it should not be construed as a limitation on the protection scope of the present invention.

[0030] In the description of the present invention, it should be understood that for the orientation description, such as the orientation or positional relationship indicated by up, down, front, back, left, right, etc., is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the present invention.

[0031] In the description of the present invention, "greater than", "less than", "exceeding", etc. are understood as not including the number itself, and "above", "below", "within", etc. are understood as including the number itself. If there is a description of first and second, it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence relationship of the indicated technical features.

[0032] In the description of the present invention, unless otherwise clearly defined, words such as "set", "installed", "connected", etc. should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0033] Please refer to Figure 1-6 , the present invention provides a technical solution: an intelligent warehousing equipment for air freight containers with an automatic locking mechanism, including a second crossbeam frame 15, a first transfer component, a second transfer component, and a fixing component;

[0034] The first transfer component is arranged on the second crossbeam frame 15. The first transfer component includes a second transmission device 14 and two guide members 13. The second transmission device 14 is installed on the second crossbeam frame 15, and the two guide members 13 are both fixed on the second crossbeam frame 15. The two guide members 13 are respectively arranged on both sides of the upper end of the second transmission device 14. The number of the first transfer components is multiple, and multiple first transfer components are all arranged on the second crossbeam frame 15;

[0035] The second transfer component is arranged under the second crossbeam frame 15. The second transfer component includes a first pulley 3, a traction rope 4, a first transmission device 6, a base 9, a first crossbeam frame 10, and a guide base 11. The base 9 is arranged at the lower end of the second crossbeam frame 15, the first crossbeam frame 10 is welded to the upper end of the base 9, the guide base 11 slides along the surface of the first crossbeam frame 10, and the first transmission device 6 is installed on the guide base 11;

[0036] The fixing component is arranged on the second crossbeam frame 15. The fixing component includes two fixing pieces 16, two pressing springs 17, two guide rods 18 and a pressing rod 19. The two guide rods 18 both slide through the crossbeam on the second crossbeam frame 15. The two fixing pieces 16 are respectively fixed at the lower ends of the corresponding guide rods 18. The number of the fixing components is multiple, and multiple fixing components are all arranged on the second crossbeam frame 15.

[0037] The second pulley 12 is installed on the left side of the first crossbeam frame 10, and the first pulley 3 is installed on the right side of the first crossbeam frame 10.

[0038] A first motor 5 is installed on the right support of the first crossbeam frame 10. The output end of the first motor 5 is connected to the traction rope 4. The traction rope 4 passes through the first pulley 3, the second pulley 12 and is connected to the upper end of the guide base 11.

[0039] An aviation box 1 is conveyed at the upper end of the first transmission device 6, and an identical aviation box 1 is conveyed at the upper end of the second transmission device 14.

[0040] A plurality of rollers 8 are installed on the surface of the base 9, and a second motor 7 is installed on one side of the base 9. The second motor 7 is electrically connected to the plurality of rollers 8.

[0041] The second transfer component is arranged between a plurality of first transfer components, and a trailer 2 is arranged outside the second crossbeam frame 15.

[0042] A plurality of pressing rods 19 are all installed on the crossbeam of the second crossbeam frame 15. The two ends of the plurality of pressing rods 19 are respectively connected to the corresponding pressing springs 17.

[0043] The upper ends of the plurality of pressing springs 17 are fixedly connected to the crossbeam of the second crossbeam frame 15, and the lower ends of the plurality of pressing springs 17 are respectively fixedly connected to the upper ends of the corresponding fixing pieces 16.

[0044] When it is necessary to transfer the aviation box 1;

[0045] First, scan the label on the aviation box 1 to judge the information of the aviation box 1.

[0046] Secondly, place the airline container 1 on the trailer 2. Subsequently, after the trailer 2 drives the airline container 1 to a suitable position, first bring the airline container 1 into contact with the upper end of the second transmission device 14 on the right side. Then, start the second transmission device 14 to drive the airline container 1 to the upper surface of the first transmission device 6 on the guiding base 11. Next, start the first transmission device 6 to drive the airline container 1 to move to the middle of the first transmission device 6. Then, start the second motor 7. The start of the second motor 7 drives a plurality of rollers 8 to rotate and drive the base 9 to move to a suitable position. After that, start the first motor 5 to drive the towing rope 4 to move. The movement of the towing rope 4 drives the guiding base 11 to move up and down. The movement of the guiding base 11 drives the first transmission device 6 to move up and down. The up and down movement of the first transmission device 6 drives the airline container 1 to move up and down to a suitable height. Subsequently, start the first transmission device 6 to drive the airline container 1 to move. After the airline container 1 moves to the upper surface of the corresponding second transmission device 14, then start the second transmission device 14 to drive the airline container 1 to move to a suitable position.

[0047] Finally, start the pressing member 19. The start of the pressing member 19 drives the two pressing springs 17 to move downward synchronously. The two pressing springs 17 respectively drive the corresponding fixing members 16 to move downward. The two fixing members 16 move downward synchronously to fix the position of the airline container 1.

[0048] Equipment safety device all-round closed-circuit monitoring device: Use multi-directional high-definition cameras to conduct 24-hour real-time monitoring of the storage area;

[0049] Photoelectric safety device: Use an infrared induction device to detect whether the cargo box deviates during operation. If it deviates, the equipment stops running, which can ensure the safe operation of the entire storage area;

[0050] AKE box automatic locking device: When the container is placed in the storage position, the lock automatically locks to ensure the safe placement of the airline container; when the container exits the warehouse, the stacker automatically unlocks;

[0051] Lifting limit protection device: After the equipment is lifted in place, lock the lifting device through a mechanical bolt to ensure lifting safety.

[0052] System operation centralized monitoring device: A centralized monitoring room is set up in this warehouse. The monitoring room is equipped with a host computer system to collect the operation data of the warehousing equipment (PLC) in real time. It can not only understand the operation status of the equipment, but also realize the automatic inventory of stored boxes and the display of remaining positions in the warehouse, and can be connected to a printer for printing. It can also transmit the real-time data to the airport management cloud.

[0053] Warehousing wind prevention, earthquake prevention, ventilation, and fire protection measures

[0054] Wind prevention measures: The equipment is set for external maintenance (warehouse), and the exterior wall is made of rock wool sandwich decorative panels, which are both heat-insulating and decorative, with colors coordinated with the airport buildings, being beautiful and grand.

[0055] Shockproof measures: The structure of the external maintenance (warehouse) of the equipment is designed in accordance with the airport shockproof level regulations.

[0056] Ventilation measures: 24 power ventilators are designed on the roof of the external maintenance (warehouse); louver windows are installed around the exterior wall to achieve natural ventilation.

[0057] Fire protection measures:

[0058] The structure is painted with fireproof coating, and the fire resistance rating is above 2.5 hours;

[0059] One fire hydrant is set at each end of the warehouse for timely fire extinguishing;

[0060] When the two end gates are opened, the fire truck can enter and directly extinguish the fire;

[0061] The fire truck can spray water to extinguish the fire through the louver windows around.

[0062] By setting the transfer component one and the transfer component two, the transmission device two 14 of the transfer component one on the right can transfer the aviation box to the transfer component two. Subsequently, the transfer component two drives the aviation box 1 to move to a suitable position, and then, in cooperation with the transfer component one, places the aviation box in a suitable position. The whole process does not require manual handling, etc. Moreover, since the transfer positions can be stored in the cloud, there is no need for manual counting of aviation boxes, thus reducing subsequent work and saving manpower.

[0063] By setting the transfer component two, the motor one 5 in the transfer component two can drive the guiding base 11 to a suitable height, thereby lifting and lowering the aviation box, eliminating the need for workers to lift it, etc., and thus greatly reducing the work intensity of workers.

[0064] By setting the fixing component, the fixing component can fix the aviation box 1 on the transmission device two 14, preventing the aviation box 1 from shaking and falling off with the crossbeam frame two 15 when other aviation boxes are placed, that is, ensuring the safety of the aviation box 1.

[0065] By setting the guiding parts 13 in the transfer component two, the two guiding parts 13 can guide the aviation box 1, preventing the aviation box from shifting when being driven by the transmission device two 14, that is, ensuring the certainty of the position of the aviation box during the whole transfer process, so as to better carry out the transfer work of the aviation box 1.

[0066] More detailed description: The three-dimensional warehouse system runs automatically according to the program. When the stacker 27 runs to the designated cargo position for placing the air box, the stacker 27 will automatically stop accurately on the track and accurately position itself with a very small error, within 3mm.

[0067] There is a push rod unlocking mechanism on the top of the stacker car 28, see Figure 4 , Figure 5 , Figure 6 ;

[0068] Each cargo space where the air box 1 is placed has a clamping mechanism on the top thereof and is in an automatic clamping state.

[0069] To place the air box 1 on the cargo position, first, the push rod unlocking motor is activated, the push rod is pushed out, and the clamping mechanism 20 is lifted up and in an unlocked state. Then the air box 1 can be accurately delivered to the cargo position.

[0070] The push rod unlocks the motor and moves in the reverse direction, and the push rod is retracted. The clamping mechanism 20 automatically presses the aviation box downward and gives a suitable clamping force to ensure that the aviation box 1 does not fall over.

[0071] Specific steps: When the stacker 27 delivers the air box 1 to the designated cargo position, the clamping mechanism 20 on the stacker 27 is actively released and unlocked.

[0072] At the same time, the motor and gear mechanism 21 on the top of the stacker 27 start to run, the rack push rod mechanism 22 extends forward on the push rod mechanism support 23, the push rod mechanism push rod head is a V-shaped convex head, which engages with the V-shaped concave head 24 on the clamping mechanism 20, and then the push rod continues to move forward, so that the wedge block 26 also moves forward.

[0073] The wedge block 26 lifts up the entire clamping mechanism 20 through the wedge surface. After being lifted up by about 40 mm, the travel stopper 30 triggers the travel detection switch 29, and the motor and gear mechanism 21 stop moving. At this time, the unlocking mechanism is completely in the unlocking state.

[0074] The conveying system on the stacker car 28 then delivers the air box 1 to the cargo position.

[0075] After the air box is delivered to the cargo position, the motor and gear mechanism 21 on the top of the stacker start to run in reverse.

[0076] The rack push rod mechanism 22 is retracted onto the stacker on the push rod mechanism support 23 , and the push rod head of the push rod mechanism is a V-shaped convex head, which is disengaged from the V-shaped concave head 24 on the clamping mechanism 20 .

[0077] Meanwhile, the automatic return spring 25 behind the V-shaped concave head 24 acts, and the wedge block 26 is completely disengaged from the wedge surface of the pressing mechanism 20. Then, without the upward lifting force of the pressing mechanism, the four pressing springs 17 on the pressing mechanism 20 automatically press the aviation box 1 downward, causing the four pressing and fixing parts 16 to tightly press on the aviation box 1.

[0078] When taking the aviation box 1, the aviation box 1 in the storage location is sent to the stacker car 28 on the stacker 27, and its operation is opposite to that described above.

[0079] Working principle:

[0080] When it is necessary to transfer the aviation box 1;

[0081] First of all, scan the label on the aviation box 1 to judge the information of the aviation box 1.

[0082] Secondly, place the aviation box 1 on the trailer 2. Subsequently, after the trailer 2 drives the aviation box 1 to a suitable position, the aviation box 1 first contacts the upper end of the transmission device two 14 on the right side. Subsequently, start the transmission device two 14 to drive the aviation box 1 to the upper surface of the transmission device one 6 on the guiding base 11. Subsequently, start the transmission device one 6 to drive the aviation box 1 to move to the middle of the transmission device one 6. Subsequently, start the motor two 7. The start of the motor two 7 drives a plurality of rollers 8 to rotate and drives the base 9 to move to a suitable position. Then, start the motor one 5 to drive the traction rope 4 to move. The movement of the traction rope 4 drives the guiding base 11 to move up and down. The movement of the guiding base 11 drives the transmission device one 6 to move up and down. The up and down movement of the transmission device one 6 drives the aviation box 1 to move up and down to a suitable height. Subsequently, start the transmission device one 6 to drive the aviation box 1 to move. After the aviation box 1 moves to the upper surface of the corresponding transmission device two 14, subsequently, start the transmission device two 14 to drive the aviation box 1 to move to a suitable position.

[0083] Finally, start the pressing rod 19. The start of the pressing rod 19 drives the two pressing springs 17 to move downward synchronously. The two pressing springs 17 respectively drive the corresponding fixing parts 16 to move downward. The two fixing parts 16 move downward synchronously to fix the position of the aviation box 1.

[0084] The above has described the embodiments of the present invention in detail with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art in the technical field, various changes can be made without departing from the purpose of the present invention.

Claims

1. An intelligent storage equipment for air freight containers with an automatic locking mechanism, characterized in that: include: A second crossbeam frame (15), a first transfer assembly, a second pulley (12), a second transfer assembly and a fixing assembly; The transfer assembly one is arranged on the second crossbeam frame (15), and the transfer assembly one comprises a second transmission device (14) and two guide members (13). The second transmission device (14) is installed on the second crossbeam frame (15), and the two guide members (13) are fixed on the second crossbeam frame (15). The two guide members (13) are respectively arranged on both sides of the upper end of the second transmission device (14). There are a plurality of transfer assemblies one, and the plurality of transfer assemblies one are all arranged on the second crossbeam frame (15); The transfer assembly 2 is arranged under the cross beam frame 2 (15), and the transfer assembly 2 comprises a pulley 1 (3), a traction rope (4), a transmission device 1 (6), a base (9), a cross beam frame 1 (10) and a guide base (11), the base (9) is arranged at the lower end of the cross beam frame 2 (15), the cross beam frame 1 (10) is welded to the upper end of the base (9), the guide base (11) slides along the surface of the cross beam frame 1 (10), and the transmission device 1 (6) is installed on the guide base (11); The fixing assembly is arranged on the second crossbeam frame (15), and the fixing assembly comprises two fixing members (16), two compression springs (17), two guide rods (18) and a compression rod member (19). The two guide rods (18) are slidably passed through the crossbeam on the second crossbeam frame (15), and the two fixing members (16) are respectively fixed to the lower ends of the corresponding guide rods (18). There are a plurality of fixing members, and the plurality of fixing members are arranged on the second crossbeam frame (15).

2. The intelligent storage equipment for air freight containers with an automatic locking mechanism according to claim 1 is characterized in that: The pulley 2 (12) is installed on the left side of the crossbeam frame 1 (10), and the pulley 1 (3) is installed on the right side of the crossbeam frame 1 (10).

3. The intelligent storage equipment for air freight containers with an automatic locking mechanism according to claim 1 is characterized in that: A motor 1 (5) is installed on the right side bracket of the crossbeam frame 1 (10), and the output end of the motor 1 (5) is connected to a traction rope (4), and the traction rope (4) passes through a pulley 1 (3), a pulley 2 (12) and is connected to the upper end of the guide base (11).

4. The intelligent storage equipment for air freight containers with an automatic locking mechanism according to claim 1 is characterized in that: The upper end of the transmission device 1 (6) conveys an aviation box (1), and the upper end of the transmission device 2 (14) conveys a similar aviation box (1).

5. The intelligent storage equipment for air freight containers with an automatic locking mechanism according to claim 1 is characterized in that: A plurality of rollers (8) are mounted on the surface of the base (9), and a second motor (7) is mounted on one side of the base (9), wherein the second motor (7) is electrically connected to the plurality of rollers (8).

6. The intelligent storage equipment for air freight containers with an automatic locking mechanism according to claim 1 is characterized in that: The second transfer component is arranged between a plurality of first transfer components, and a trailer (2) is arranged outside the second crossbeam frame (15).

7. The intelligent storage equipment for air freight containers with an automatic locking mechanism according to claim 1 is characterized in that: The plurality of clamping rods (19) are mounted on the crossbeam of the second crossbeam frame (15), and the two ends of the plurality of clamping rods (19) are respectively connected to corresponding clamping springs (17).

8. The intelligent storage equipment for air freight containers with an automatic locking mechanism according to claim 1 is characterized in that: The upper ends of the plurality of compression springs (17) are fixedly connected to the crossbeam of the second crossbeam frame (15), and the lower ends of the plurality of compression springs (17) are respectively fixedly connected to the upper ends of the corresponding fixing members (16).

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