A tension-adaptive quick-frozen food conveyor chain

By designing a tension-adaptive quick-frozen food conveyor chain, utilizing the quick disassembly and replacement of the chain plate assembly and the adjustment assembly and the coordination of the tension spring adjustment rod, the problem of the conveyor chain breaking when the tension changes is solved, thereby improving maintenance efficiency and conveying efficiency.

CN120057501BActive Publication Date: 2025-09-30NINGXIA SHENGFEIHAO SUPPLY CHAIN MANAGEMENT CO LTD
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Patent Information

Application Number
CN202510446555.7
Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Filing Date
2025-04-10
Publication Date
2025-09-30
Estimated Expiration
2045-04-10

AI Technical Summary

Technical Problem

Existing quick-frozen food conveyor chains are prone to breaking when tension changes, resulting in high maintenance costs and affecting conveying efficiency.

Method used

The quick-frozen food conveyor chain with adaptive tension is adopted. The chain pieces can be quickly disassembled and replaced through the chain piece assembly and the adjustment assembly. The tension of the conveyor chain can be adaptively adjusted by combining the tension spring and the adjustment rod.

Benefits of technology

It enables quick replacement of damaged chain segments, reduces maintenance costs and time, avoids chain breakage caused by excessive tension, and maintains conveying efficiency.

✦ Generated by Eureka AI based on patent content.

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Abstract

The present invention relates to the technical field of quick-frozen food conveying, specifically to a tension-adaptive quick-frozen food conveying chain, comprising: a conveying chain, wherein two conveying chains are symmetrically arranged, the conveying chain transmission is arranged on a conveyor, and a chain piece assembly and an adjustment assembly are arranged on the conveying chain; after the first chain piece is equidistantly arranged on a sleeve, the sleeve is sleeved on a fixed rod and the fixed rod is installed and connected to the conveying chain, after the second chain piece is equidistantly arranged on a connecting rod, the adjustment rod is staggeredly inserted into a movable groove and then into a connecting hole, and the two ends of the adjustment rod are connected to the fixing blocks to complete the assembly of the quick-frozen food conveying chain, the operation is simple, and the first chain piece and the second chain piece can be quickly disassembled and replaced separately after being damaged, thereby reducing maintenance costs and time and avoiding affecting the conveying efficiency of the quick-frozen food conveying chain; at the same time, a tension spring is arranged to have a pulling effect on the adjustment rod, which cooperates with the adjustment rod to move in the movable groove to achieve self-adaptive adjustment of the conveying chain tension and avoid the conveying chain from breaking.
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Description

Technical Field

[0001] The invention relates to the technical field of quick-frozen food conveying, in particular to a tension-adaptive quick-frozen food conveying chain. Background Art

[0002] The existing Chinese patent document with publication number CN217755351U discloses a flexibly bendable conveyor mesh belt structure, relating to the field of conveyor mesh belt technology and aiming to address the technical problem of conveyor mesh belts being unable to bend flexibly. The key technical solution comprises a plurality of parallel mesh belt threading shafts, each of which is fitted with a metal mesh, with the adjacent metal meshes arranged in a staggered pattern. Mesh belt chain plates are provided at both ends of the adjacent mesh belt threading shafts, one end of each of which is fixedly connected to one mesh belt threading shaft and the other end of each of which is movably connected to the other mesh belt threading shaft. The purpose is to provide a flexibly bendable conveyor mesh belt structure.

[0003] However, in the above-mentioned scheme and the prior art, when transporting quick-frozen foods, the surface of the conveyor chain on the conveyor is usually set to a metal mesh to bear the weight of the quick-frozen foods. During the operation and transmission of the conveyor chain, the conveyor chain cannot adapt to the change in tension, which can easily cause the conveyor chain surface to break somewhere. After that, the entire conveyor chain usually needs to be disassembled and replaced. The maintenance cost is high and time-consuming, which affects the efficiency of the conveyor in transporting quick-frozen foods and needs to be improved and optimized. Summary of the Invention

[0004] The object of the present invention is to provide a tension-adaptive quick-frozen food conveyor chain to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: a tension-adaptive quick-frozen food conveyor chain, comprising:

[0006] Conveyor chains, wherein two conveyor chains are symmetrically arranged, the conveyor chain transmission is arranged on the conveyor, and the conveyor chain is provided with a chain piece assembly and an adjustment assembly;

[0007] The chain plate assembly comprises a fixing rod, a sleeve, a connecting rod and an adjusting rod, wherein the sleeve is sleeved on the fixing rod.

[0008] Preferably, first positioning holes are symmetrically provided on the circumferential walls at both ends of the fixing rod, a T-shaped block is fixedly provided on the side wall of the limiting plate, a first insertion hole is provided on the side end of the limiting plate, the first insertion hole passes through the T-shaped block, and the end of the fixing rod is inserted into the first insertion hole.

[0009] Preferably, a card slot is provided on the side wall of the T-shaped block, a slot is provided on the bottom wall of the card slot, the slot passes through the first plug hole, a card block is movably embedded in the card slot, a first positioning column is fixedly provided on the side wall of the card block, the first positioning column is plugged into the slot, and the first positioning column is plugged into the first plug hole.

[0010] Preferably, mounting protrusions are fixedly provided at equal intervals on the side walls of the conveying chain, a T-slot is provided on the mounting protrusion, the T-slot is plugged into the T-block, the clamping block is clamped into the side wall of the T-slot, a round hole is provided on the side wall of the T-slot, a threaded groove is provided on the side wall of the T-block, and the knob screw passes through the round hole and is threadedly connected to the threaded groove.

[0011] Preferably, externally threaded tubes are symmetrically fixedly provided at both ends of the sleeve, the externally threaded tubes are sleeved with the fixing rod, the externally threaded tubes are clamped with the limiting plate, and a first nut is threadedly provided on the externally threaded tubes.

[0012] Preferably, the sleeve is provided with a first connecting ring at equal intervals, the adjacent first connecting ring side walls on the sleeve are clamped, the first connecting ring at the upper end of the sleeve is clamped with the first nut, the first connecting ring is fixedly provided with a first chain plate on the peripheral wall, and a movable groove is opened on the side wall of the first chain plate.

[0013] Preferably, threaded columns are symmetrically fixed at both ends of the connecting rod, second nuts are threadedly connected to the threaded columns, and second connecting rings are equidistantly sleeved on the connecting rod.

[0014] Preferably, the adjacent second connecting ring side walls on the connecting rod are clamped, the second connecting ring at the upper end of the connecting rod is clamped with the second nut, a second chain plate is fixedly provided on the circumferential wall of the second connecting ring, and a connecting hole is fixedly provided at the end of the second chain plate.

[0015] Preferably, the adjusting rod is movably engaged with the movable groove, the adjusting rod is sleeved with the connecting hole, the first chain plate and the second chain plate are staggered, second positioning holes are symmetrically provided on the circumferential walls at both ends of the adjusting rod, a second insertion hole is provided on the side wall of the fixed block, the end of the adjusting rod is plugged into the second insertion hole, a threaded hole is provided on the side wall of the fixed block, the threaded hole passes through the second insertion hole, a knob bolt is threadedly provided in the threaded hole, a second positioning column is fixedly provided on the end of the knob bolt, and the second positioning column is plugged into the second positioning hole.

[0016] Preferably, spring hooks are symmetrically fixed at both ends of the tension spring in the adjustment assembly, the first pull ring is fixed on the side wall of the mounting protrusion, and the second pull ring is fixed on the side wall of the fixed block. The spring hook on one side of the tension spring is buckled with the first pull ring, and the spring hook on the other side is buckled with the second pull ring.

[0017] Compared with the prior art, this application has the following beneficial effects:

[0018] By arranging the first chain pieces equidistantly on the sleeve, the external threaded pipes on both sides of the sleeve are threadedly connected to the first nut to prevent the first connecting ring on the sleeve from falling off. After that, the sleeve is sleeved with the fixed rod, and the two ends of the fixed rod are installed and connected to the conveying chain. After the second chain pieces are equidistantly arranged on the connecting rod, the threaded columns at both ends of the connecting rod are threadedly connected to the second nuts to prevent the second connecting ring on the connecting rod from falling off. The adjusting rod is staggered and inserted into the movable groove on the first chain piece and the connecting hole on the second chain piece, so that the first chain piece and the second chain piece are in a staggered state. The two ends of the adjusting rod are fixedly connected to the fixing block to complete the assembly of the quick-frozen food conveyor chain. The operation is simple, and the first chain piece and the second chain piece can be quickly disassembled and replaced separately after being damaged. There is no need to disassemble the entire conveyor chain for replacement, which reduces maintenance costs and time and avoids affecting the conveying efficiency of the quick-frozen food conveyor chain.

[0019] By connecting the spring buckles on both sides of the tension spring to the first pull ring and the second pull ring respectively, there is a pulling effect on the adjusting rod. When the quick-frozen food is transported on the conveyor chain, the tension spring stretches when the first chain plate and the second chain plate carry the quick-frozen food, and the adjusting rod moves in the movable groove, thereby realizing adaptive adjustment of the conveyor chain tension and avoiding excessive tension during use that may cause the conveyor chain to break. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the connection of the conveyor chain structure of the present invention;

[0022] Figure 3 This is a schematic diagram of the connection of the fixing rod structure of the present invention;

[0023] Figure 4 This is an exploded view of the fixing rod structure connection of the present invention;

[0024] Figure 5 This is an exploded view of the sleeve structure connection of the present invention;

[0025] Figure 6 This is an exploded view of the connecting rod structure of the present invention;

[0026] Figure 7 This is an exploded view of the adjustment rod structure connection of the present invention;

[0027] Figure 8 This is a schematic diagram of the connection of the tension spring structure of the present invention.

[0028] In the figure: conveyor chain 1, fixed rod 2, first positioning hole 201, limiting plate 202, T-shaped block 203, first jack 204, slot 205, slot 206, block 207, first positioning column 208, mounting protrusion 209, T-shaped slot 210, round hole 211, threaded groove 212, sleeve 3, external threaded tube 301, first nut 302, first connecting ring 303, first chain piece 304, movable slot 305, Connecting rod 4, threaded column 401, second nut 402, second connecting ring 403, second chain plate 404, connecting hole 405, adjusting rod 5, second positioning hole 501, fixing block 502, second plug hole 503, threaded hole 504, knob bolt 505, second positioning column 506, tension spring 6, spring buckle 601, first pull ring 602, second pull ring 603, magnetic plate 7, first magnetic block 701, second magnetic block 702. DETAILED DESCRIPTION

[0029] 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.

[0030] See also Figure 1-8 , the present invention provides the following three preferred embodiments:

[0031] Embodiment 1: A tension-adaptive quick-frozen food conveyor chain, comprising: a conveyor chain 1, wherein two conveyor chains 1 are symmetrically arranged, the conveyor chain 1 is arranged on a conveyor, and a chain piece assembly and an adjustment assembly are arranged on the conveyor chain 1; the chain piece assembly comprises a fixed rod 2, a sleeve 3, a connecting rod 4 and an adjustment rod 5, and the sleeve 3 is sleeved on the fixed rod 2; first positioning holes 201 are symmetrically opened on the circumferential wall at both ends of the fixed rod 2, a T-shaped block 203 is fixedly arranged on the side wall of the limiting plate 202, a first plug hole 204 is opened on the side end of the limiting plate 202, the first plug hole 204 passes through the T-shaped block 203, the fixed rod 2 ends are inserted into the first socket 204; a slot 205 is provided on the side wall of the T-shaped block 203, and a slot 206 is provided on the bottom wall of the slot 205. The slot 206 passes through the first socket 204, and a block 207 is movably embedded in the slot 205. A first positioning column 208 is fixedly provided on the side wall of the block 207. The first positioning column 208 is plugged into the slot 206, and the first positioning column 208 is plugged into the first socket 204; mounting protrusions 209 are fixedly provided at equal intervals on the side wall of the conveyor chain 1, and a T-shaped slot 210 is provided on the mounting protrusion 209. The T-shaped slot 210 is plugged into the T-shaped block 203, and the block 207 is plugged into the T The side wall of the T-shaped groove 210 is clamped, a circular hole 211 is opened on the side wall of the T-shaped groove 210, and a threaded groove 212 is opened on the side wall of the T-shaped block 203. The knob screw passes through the circular hole 211 and is threadedly connected to the threaded groove 212; the two ends of the sleeve 3 are symmetrically fixed with external threaded tubes 301, the external threaded tube 301 is sleeved with the fixing rod 2, the external threaded tube 301 is clamped with the limiting plate 202, and a first nut 302 is threadedly provided on the external threaded tube 301; the first connecting ring 303 is equidistantly sleeved on the sleeve 3, the side walls of the adjacent first connecting rings 303 on the sleeve 3 are clamped, and the first connecting ring 303 at the upper end of the sleeve 3 is clamped with the first nut 302 is clamped, a first chain piece 304 is fixedly provided on the peripheral wall of the first connecting ring 303, and a movable groove 305 is opened on the side wall of the first chain piece 304; threaded columns 401 are symmetrically fixedly provided at both ends of the connecting rod 4, and second nuts 402 are threadedly connected to the threaded columns 401, and second connecting rings 403 are equidistantly sleeved on the connecting rod 4; the side walls of adjacent second connecting rings 403 on the connecting rod 4 are clamped, and the second connecting ring 403 at the upper end of the connecting rod 4 is clamped with the second nut 402, and a second chain piece 404 is fixedly provided on the peripheral wall of the second connecting ring 403, and a connecting hole 405 is fixedly provided at the end of the second chain piece 404;The adjusting rod 5 is movably engaged with the movable slot 305 and sleeved with the connecting hole 405. The first and second chain plates 304 and 404 are staggered. Second positioning holes 501 are symmetrically formed on the walls at both ends of the adjusting rod 5. A second insertion hole 503 is formed on the side wall of the fixing block 502. The end of the adjusting rod 5 is plugged into the second insertion hole 503. A threaded hole 504 is formed on the side wall of the fixing block 502. The threaded hole 504 passes through the second insertion hole 503. A knob bolt 505 is threadedly connected to the threaded hole 504. A second positioning post 506 is fixed to the end of the knob bolt 505. The second positioning post 506 is plugged into the second positioning hole 501.

[0032] When in use, first thread the external threaded tube 301 on one side of the sleeve 3 to connect the first nut 302, then equidistantly sleeve the first connecting ring 303 on the sleeve 3 so that the external threaded tube 301 on the other side of the sleeve 3 is threaded to connect the first nut 302 to prevent the first connecting ring 303 on the sleeve 3 from falling off, then insert the fixing rod 2 into the sleeve 3 and the external threaded tube 301, so that the two ends of the fixing rod 2 are inserted into the first insertion hole 204, insert the first positioning column 208 into the slot 206 and the first positioning hole 201 until the block 207 is embedded in the slot 205, and then insert the T-shaped block 203 into the T-shaped slot 210 At this time, the inner wall limit block 207 of the T-shaped groove 210 fixes the position of the fixing rod 2, so that the knob screw passes through the round hole 211 and is threadedly connected with the thread groove 212 to complete the installation connection between the fixing rod 2 and the conveyor chain 1; after the threaded column 401 on one side of the connecting rod 4 is threadedly connected to the second nut 402, the second connecting ring 403 is equidistantly sleeved on the connecting rod 4, so that the threaded column 401 on the other side of the connecting rod 4 is threadedly connected to the second nut 402 to prevent the second connecting ring 403 on the connecting rod 4 from falling off; then the adjusting rod 5 is inserted into the movable groove 305 on the first chain piece 304 and connected to the connecting hole 405 on the second chain piece 404 After the first chain piece 304 and the second chain piece 404 are connected to the adjusting rod 5 in an interlaced state, the end of the adjusting rod 5 is inserted into the second insertion hole 503, and the knob bolt 505 is screwed into the threaded hole 504 so that the second positioning column 506 is inserted into the second positioning hole 501 to complete the installation of the adjusting rod 5. At this time, the fixing blocks 502 on both sides of the adjusting rod 5 are respectively engaged with the first chain piece 304 and the second chain piece 404 to ensure that the adjusting rod 5 can move horizontally along the movable groove 305; repeat the above operation, and the conveying chain 1 is driven and set on the conveyor so that the conveying chain 1 cooperates with the setting of the first chain piece 304 And the second chain piece 404 forms a quick-frozen food conveyor chain for conveying quick-frozen food; the operation is simple, and the first chain piece 304 and the second chain piece 404 can be quickly replaced after being damaged. After the sleeve 3 for the first chain piece 304 is pre-installed and the connecting rod 4 for the second chain piece 404 is pre-installed, the conveyor chain can be put into use again, and then the damaged first chain piece 304 on the disassembled sleeve 3 can be disassembled and replaced separately, and the damaged second chain piece 404 on the connecting rod 4 can be disassembled and replaced separately. There is no need to disassemble the entire conveyor chain for replacement, which reduces maintenance costs and time and avoids affecting the conveying efficiency of the quick-frozen food conveyor chain.

[0033] Example 2, based on Example 1: spring hooks 601 are symmetrically fixed at both ends of the tension spring 6 in the adjustment assembly, the first pull ring 602 is fixed on the side wall of the mounting protrusion 209, and the second pull ring 603 is fixed on the side wall of the fixed block 502, the spring hook 601 on one side of the tension spring 6 is buckled with the first pull ring 602, and the spring hook 601 on the other side is buckled with the second pull ring 603.

[0034] During use, the damper is sleeved inside the tension spring 6, and the two ends of the damper are fixedly connected to the spring buckles 601 at both ends of the tension spring 6. After the first chain piece 304 and the second chain piece 404 are set and installed, the spring buckle 601 on one side of the tension spring 6 is buckled with the first pull ring 602 on the installation protrusion 209, and the spring buckle 601 on the other side of the tension spring 6 is buckled with the second pull ring 603 on the fixed block 502, thereby having a pulling effect on the adjusting rod 5, so that when the quick-frozen food is transported on the conveyor chain, when the first chain piece 304 and the second chain piece 404 carry the quick-frozen food, the tension spring 6 is stretched to cooperate with the adjusting rod 5 to move in the movable groove 305, thereby realizing adaptive adjustment of the conveyor chain tension, and avoiding excessive tension during use causing the conveyor chain to break.

[0035] Example 3, based on Example 2: an auxiliary component is provided, which includes a magnetic plate 7, a first magnetic block 701 and a second magnetic block 702; the first magnetic block 701 is fixedly embedded in the side end of the first chain piece 304, and the second magnetic block 702 is fixedly embedded in the side end of the second chain piece 404, the magnetic plate 7 and the first magnetic block 701 attract each other, and the magnetic plate 7 and the second magnetic block 702 attract each other.

[0036] During use, when the adjusting rod 5 is installed, one magnetic plate 7 and the first magnetic block 701 attract each other, and then the first chain piece 304 on one side is adsorbed on the magnetic plate 7, and the other magnetic plate 7 and the second magnetic block 702 attract each other, and then the second chain piece 404 on one side is adsorbed on the magnetic plate 7. The two magnetic plates 7 are held horizontally to realize the staggered arrangement of the first chain piece 304 and the second chain piece 404, so that the adjusting rod 5 can be inserted into the movable groove 305 and the connecting hole 405 in turn, which is convenient to operate, improves the installation efficiency of the adjusting rod 5, and thus reduces the maintenance time of the conveyor chain.

[0037] Although the above describes the illustrative specific implementation methods of the present application so that those skilled in the art can understand the present application, the present application is not limited to the scope of the specific implementation methods. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present application defined and determined by the attached claims, all application creations based on the concept of the present application are protected.

Claims

1. A tension-adaptive quick-frozen food conveyor chain, characterized by: include: Conveyor chains (1), wherein two conveyor chains (1) are symmetrically arranged, the conveyor chains (1) are transmission-arranged on the conveyor, and the conveyor chains (1) are provided with chain plate components and adjustment components; A chain plate assembly, the chain plate assembly comprising a fixed rod (2), a sleeve (3), a connecting rod (4) and an adjusting rod (5), wherein the sleeve (3) is sleeved on the fixed rod (2); The sleeve (3) is provided with first connecting rings (303) at equal intervals, the side walls of adjacent first connecting rings (303) on the sleeve (3) are clamped, the first connecting ring (303) at the upper end of the sleeve (3) is clamped with the first nut (302), a first chain piece (304) is fixedly provided on the peripheral wall of the first connecting ring (303), and a movable groove (305) is provided on the side wall of the first chain piece (304); The side walls of the adjacent second connecting rings (403) on the connecting rod (4) are clamped, the second connecting ring (403) at the upper end of the connecting rod (4) is clamped with the second nut (402), a second chain piece (404) is fixedly provided on the peripheral wall of the second connecting ring (403), and a connecting hole (405) is fixedly provided at the end of the second chain piece (404); The adjusting rod (5) is movably engaged with the movable groove (305), the adjusting rod (5) is sleeved with the connecting hole (405), the first chain plate (304) and the second chain plate (404) are staggered, second positioning holes (501) are symmetrically provided on the peripheral walls at both ends of the adjusting rod (5), a second insertion hole (503) is provided on the side wall of the fixing block (502), the end of the adjusting rod (5) is plugged into the second insertion hole (503), a threaded hole (504) is provided on the side wall of the fixing block (502), the threaded hole (504) passes through the second insertion hole (503), a knob bolt (505) is provided in the threaded connection of the threaded hole (504), a second positioning column (506) is fixedly provided at the end of the knob bolt (505), and the second positioning column (506) is plugged into the second positioning hole (501).

2. The tension-adaptive quick-frozen food conveyor chain according to claim 1, characterized in that: First positioning holes (201) are symmetrically provided on the peripheral walls at both ends of the fixing rod (2), a T-shaped block (203) is fixedly provided on the side wall of the limiting plate (202), a first insertion hole (204) is provided on the side end of the limiting plate (202), the first insertion hole (204) passes through the T-shaped block (203), and the end of the fixing rod (2) is inserted into the first insertion hole (204).

3. The tension-adaptive quick-frozen food conveyor chain according to claim 2, characterized in that: A card slot (205) is provided on the side wall of the T-shaped block (203), a slot (206) is provided on the bottom wall of the card slot (205), the slot (206) passes through the first plug hole (204), a card block (207) is movably embedded in the card slot (205), a first positioning column (208) is fixedly provided on the side wall of the card block (207), the first positioning column (208) is plugged into the slot (206), and the first positioning column (208) is plugged into the first plug hole (204).

4. The tension-adaptive quick-frozen food conveyor chain according to claim 1, characterized in that: Mounting protrusions (209) are fixedly provided at equal intervals on the side wall of the conveying chain (1), a T-shaped slot (210) is provided on the mounting protrusion (209), the T-shaped slot (210) is plugged into the T-shaped block (203), the clamping block (207) is clamped into the side wall of the T-shaped slot (210), a circular hole (211) is provided on the side wall of the T-shaped slot (210), a threaded slot (212) is provided on the side wall of the T-shaped block (203), and a knob screw passes through the circular hole (211) and is threadedly connected to the threaded slot (212).

5. The tension-adaptive quick-frozen food conveyor chain according to claim 1, characterized in that: Externally threaded tubes (301) are symmetrically fixedly provided at both ends of the sleeve (3), the externally threaded tube (301) is sleeved with the fixing rod (2), the externally threaded tube (301) is clamped with the limiting plate (202), and a first nut (302) is threadedly provided on the externally threaded tube (301).

6. The tension-adaptive quick-frozen food conveyor chain according to claim 1, characterized in that: Threaded columns (401) are symmetrically fixedly provided at both ends of the connecting rod (4), second nuts (402) are provided on the threaded columns (401) in threaded connection, and second connecting rings (403) are sleeved equidistantly on the connecting rod (4).

7. The tension-adaptive quick-frozen food conveyor chain according to claim 1, characterized in that: The tension spring (6) in the adjustment assembly is symmetrically fixed with spring buckles (601) at both ends, the first pull ring (602) is fixedly arranged on the side wall of the mounting protrusion (209), and the second pull ring (603) is fixedly arranged on the side wall of the fixed block (502). The spring buckle (601) on one side of the tension spring (6) is buckled with the first pull ring (602), and the spring buckle (601) on the other side is buckled with the second pull ring (603).