Collision buffering device for highway bridge

Abstract

The utility model relates to the technical field of highway bridges, in particular to a collision buffering device of a highway bridge, which comprises a mounting frame, a buffering mechanism, a clamping ring mechanism and a plurality of rollers, one end face of the mounting frame is connected with the clamping ring mechanism, and the other end face is rotationally connected with the rollers; the rollers are arranged in a transverse array mode. The buffer mechanism is arranged in the mounting frame, and the buffer mechanism can elastically slide in the mounting frame in the longitudinal direction; the clamping ring mechanism comprises a hinging ring and a fixing bolt; the free end of the hinge ring is detachably connected with the fixing bolt. And the hinge ring is elastically connected with the mounting frame. The multiple rollers are arranged in the transverse array, so that when a vehicle collides with the collision buffering device, the vehicle firstly collides with the multiple rollers, the multiple rollers convert part of vehicle collision force into rotation driving force, and therefore the longitudinal load of the collision force is reduced, the collision force borne by the buffering mechanism is reduced, and preliminary buffering is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of highway bridges, in particular to a collision buffer device for highway bridges. Background Art

[0002] Highway bridge engineering refers to the planning, design, construction, maintenance, and repair of highway structures that cross waters, valleys, and all traffic passages. Highway bridges are frequent areas for traffic accidents, and many vehicles will crash into the guardrails of highway bridges when out of control. Guardrails are usually equipped with collision buffers, which can buffer the collision force of vehicles to improve the protective performance of the guardrails.

[0003] The existing collision buffer device has the following problems during use:

[0004] 1. The collision buffer device and the guardrail are generally fixed and installed by welding. When the collision buffer device is damaged by a vehicle collision, it is not convenient to remove the collision buffer device from the guardrail separately, and the installation and replacement of the collision buffer device is relatively cumbersome.

[0005] 2. Although the collision buffer device has a buffering function after a collision, it only relies on the simple connection of an anti-collision plate (anti-collision means preventing damage) and multiple sets of springs to achieve the anti-collision effect. When the vehicle is out of control, the direction of the collision force on the anti-collision plate is not fixed, making it difficult for multiple sets of springs to effectively buffer the collision force. The collision buffer device has poor anti-collision performance; and the spring is more likely to exceed its elastic limit under a vehicle collision, causing the spring to fail. The collision buffer device is insufficiently stable and has a short service life. Utility Model Content

[0006] 1. Technical issues to be resolved

[0007] In view of the above-mentioned shortcomings and deficiencies of the prior art, the utility model provides a collision buffer device for a highway bridge, which solves the technical problems that the disassembly and assembly of the collision buffer device is complicated, and the anti-collision performance is poor and the stability is insufficient under vehicle collision.

[0008] (II) Technical solution

[0009] In order to achieve the above-mentioned purpose, the collision buffer device of the highway bridge of the utility model comprises a mounting frame, a buffer mechanism, a clamping ring mechanism and a plurality of rollers;

[0010] One end surface of the mounting frame is connected to the clamping ring mechanism, and the other end surface is rotatably connected to the plurality of rollers; the plurality of rollers are arranged in a transverse array;

[0011] The buffer mechanism is built into the mounting frame, and the buffer mechanism can elastically slide in the longitudinal direction in the mounting frame;

[0012] The clamping ring mechanism comprises an articulated ring and a fixing bolt; the free end of the articulated ring is detachably connected to the fixing bolt; and the articulated ring is elastically connected to the mounting frame.

[0013] Optionally, the buffer mechanism includes an anti-collision plate, a pair of sliders and a pair of buffer springs;

[0014] The top end and the bottom end of the inner wall of the mounting frame are provided with sliding grooves correspondingly;

[0015] The slider is connected to the slide groove in a sliding manner along the longitudinal direction; one end of the buffer spring is connected to the slide groove, and the other end is connected to the slider;

[0016] The top end and the bottom end of the anti-collision plate are correspondingly connected to a pair of the sliding blocks.

[0017] Optionally, the buffer mechanism further includes a plurality of buffer springs;

[0018] A plurality of buffer spring sheet arrays are arranged between the mounting frame and the anti-collision plate.

[0019] Optionally, the collision buffer device further comprises a rubber strip;

[0020] The rubber strip is arranged on the mounting frame and is located directly above and / or directly below the roller.

[0021] Optionally, the clamping ring mechanism further includes a clamping ring and an adjusting bolt;

[0022] The adjusting bolt is threadedly connected to the hinge ring;

[0023] The clamping ring is arranged in the hinge ring, and the adjusting bolt is rotatably connected to the clamping ring; the opening of the clamping ring faces the mounting frame.

[0024] Optionally, the clamping ring mechanism further includes a support ring and a compression spring;

[0025] The opening of the support ring faces the opening of the clamping ring;

[0026] One end of the extrusion spring is connected to the hinge ring, and the other end is connected to the support ring.

[0027] Optionally, both the opening of the support ring and the opening of the clamping ring are provided with anti-slip pads.

[0028] Optionally, the clamping ring mechanism further comprises a connecting block and a damper; and a shock absorbing spring is arranged on the mounting frame;

[0029] The free end of the shock absorbing spring is connected to the connecting block; the damper is arranged in the shock absorbing spring.

[0030] Optionally, a fixing block is provided on the mounting frame;

[0031] The fixing block is provided with a guide groove; the shock absorbing spring is built into the guide groove;

[0032] The connecting block is slidably connected to the guide groove along the longitudinal direction.

[0033] Optionally, the mounting frame includes a support plate and a pair of buffer plates;

[0034] A pair of buffer plates are arranged at the top and bottom ends of the support plate in a one-to-one correspondence, and the three are arranged in a concave shape;

[0035] The two free ends of the roller are rotatably connected to a pair of buffer plates in a one-to-one correspondence;

[0036] The buffer mechanism is slidably connected with a pair of buffer plates along the longitudinal direction;

[0037] The clamping ring mechanism is arranged on a surface of the support plate facing away from the buffer mechanism.

[0038] (III) Beneficial effects

[0039] The beneficial effects of the utility model are:

[0040] The hinged ring can be mounted on the guardrail to achieve the installation of the collision buffer device and the guardrail. The detachable connection between the hinged ring and the fixing bolt allows the clamping ring mechanism to be quickly disassembled and assembled from the guardrail. Compared with the traditional welding connection method, the connection between the hinged ring and the fixing bolt greatly simplifies the installation process of the collision buffer device and improves the disassembly and assembly efficiency.

[0041] A plurality of rollers are arranged on the end surface of the mounting frame along a transverse array, and the rollers are rotatably connected to the mounting frame, so that when a vehicle collides with the collision buffer device, it first collides with the plurality of rollers. The plurality of rollers convert a part of the impact force of the vehicle into a self-rotation driving force, thereby reducing the longitudinal load of the impact force, and further reducing the impact force received by the buffer mechanism, thereby achieving primary buffering.

[0042] The buffer mechanism is built into the mounting frame. The buffer mechanism does not directly contact the vehicle, but moves longitudinally due to the inertia and vibration after the vehicle hits multiple rollers, and the buffer mechanism performs secondary buffering. The built-in buffer mechanism effectively avoids the vehicle directly hitting the buffer mechanism, and the impact force load on the buffer mechanism is more dispersed, thereby ensuring that the buffer mechanism can give full play to its buffering performance, thereby improving the anti-collision performance and stability of the collision buffer device.

[0043] The hinged ring is elastically connected to the mounting frame to achieve three-level buffering, which further buffers the longitudinal load after the impact force is distributed by multiple rollers, increases the upper limit of the buffering force of the collision buffer device, and thereby improves the protective performance of the guardrail. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic structural diagram of a collision buffer device for a highway bridge of the utility model;

[0045] Figure 2 It is a side view of the collision buffer device of the highway bridge of the utility model;

[0046] Figure 3 It is a schematic diagram of the connection between the collision buffer device and the guardrail of the highway bridge of the utility model;

[0047] Figure 4 for Figure 2 Enlarged view of point A in the middle.

[0048] [Description of Reference Numerals]

[0049] 1: mounting frame; 11: fixing block; 12: supporting plate; 13: buffer plate;

[0050] 2: buffer mechanism; 21: anti-collision plate; 22: slider; 23: buffer spring; 24: buffer spring;

[0051] 3: clamping ring mechanism; 31: hinged ring; 311: fixing bolt; 32: clamping ring; 33: adjusting bolt; 34: extrusion spring; 35: anti-slip pad; 36: connecting block; 37: supporting ring;

[0052] 4: Roller;

[0053] 5: Rubber strip;

[0054] 6: shock-absorbing spring;

[0055] 7: Guardrail. DETAILED DESCRIPTION

[0056] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0057] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0058] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0059] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; "connection" can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] See also Figure 1 and Figure 2 The utility model provides a collision buffer device for a highway bridge, which includes a mounting frame 1, a buffer mechanism 2, a clamping ring mechanism 3 and a plurality of rollers 4; one end face of the mounting frame 1 is connected to the clamping ring mechanism 3, and the other end face is rotatably connected to the plurality of rollers 4; the plurality of rollers 4 are arranged along a transverse array; the buffer mechanism 2 is built into the mounting frame 1, and the buffer mechanism 2 can elastically slide in the longitudinal direction inside the mounting frame 1; the clamping ring mechanism 3 includes a hinged ring 31 and a fixing bolt 311; the free end of the hinged ring 31 is detachably connected to the fixing bolt 311; the hinged ring 31 is elastically connected to the mounting frame 1. Among them, the transverse direction is the axial direction of the clamping ring mechanism 3, that is, the axial direction of the railing of the guardrail 7; the longitudinal direction is the direction perpendicular to the end face of the mounting frame 1; and the vertical direction is the height direction. The transverse, longitudinal and vertical directions are perpendicular to each other.

[0061] like Figure 3 As shown, the hinged ring 31 is hinged by a pair of open and closed arc rings, and the free ends of the pair of arc rings are fixed by fixing bolts 311. The hinged ring 31 can be sleeved on the railing of the guardrail 7 to achieve the installation of the collision buffer device and the guardrail 7. The detachable connection between the hinged ring 31 and the fixing bolts 311 enables the clamping ring mechanism 3 to be quickly disassembled and assembled with the railing of the guardrail 7. Compared with the traditional welding connection method, the connection between the hinged ring 31 and the fixing bolts 311 greatly simplifies the installation process of the collision buffer device and improves the disassembly efficiency.

[0062] A plurality of rollers 4 are arranged on the end surface of the mounting frame 1 along a transverse array, and the rollers 4 are rotatably connected to the mounting frame 1, so that when a vehicle collides with the collision buffer device, it first collides with the plurality of rollers 4, and the plurality of rollers 4 convert a part of the impact force of the vehicle into a self-rotation driving force, thereby reducing the longitudinal load of the impact force, and further reducing the impact force received by the buffer mechanism 2, thereby realizing primary buffering.

[0063] The buffer mechanism 2 is built into the mounting frame 1. The buffer mechanism 2 does not directly contact the vehicle, but moves longitudinally due to the inertia and vibration after the vehicle hits the multiple rollers 4, and the buffer mechanism 2 performs secondary buffering. The buffer mechanism 2 is built in, which effectively avoids the vehicle directly hitting the buffer mechanism 2, and the impact force load on the buffer mechanism 2 is more dispersed, thereby ensuring that the buffer mechanism 2 can give full play to its buffering performance, thereby improving the anti-collision performance and stability of the collision buffer device.

[0064] The hinge ring 31 is elastically connected to the mounting frame 1 to achieve three-level buffering, further buffering the longitudinal load after the impact force is distributed by multiple rollers 4, improving the upper limit of the buffering force of the collision buffer device, and thus improving the protective performance of the guardrail.

[0065] Furthermore, the buffer mechanism 2 includes an anti-collision plate 21, a pair of sliders 22 and a pair of buffer springs 23; the top and bottom of the inner wall of the mounting frame 1 are provided with corresponding slide grooves; the slider 22 is connected to the slide groove in a longitudinal sliding manner; one end of the buffer spring 23 is connected to the slide groove, and the other end is connected to the slider 22; the top and bottom ends of the anti-collision plate 21 are connected to the pair of sliders 22 in a corresponding manner. Specifically, after the vehicle hits multiple rollers 4, the secondary buffer and the tertiary buffer are carried out simultaneously, and the anti-collision plate 21 moves longitudinally toward the roller 4 due to inertia and vibration, thereby driving the pair of sliders 22 to move longitudinally. During this process, the pair of buffer springs 23 are continuously compressed to buffer the impact load. The tertiary buffer is that after the multiple rollers 4 are hit, the mounting frame 1 is driven to move longitudinally toward the roller 4, and the elastic structure between the mounting frame 1 and the roller 4 buffers the impact load.

[0066] Since the clamping ring mechanism 3 is similar to a sleeve member, the mounting frame 1 can be stably mounted on the guardrail 7 through the clamping ring mechanism 3, thereby ensuring the structural strength of the mounting frame 1, thereby ensuring the connection strength of the multiple rollers 4 on the mounting frame 1. When a vehicle hits the multiple rollers 4, it is equivalent to the vehicle hitting a vertical plane, that is, the impact direction of the mounting frame 1 and the buffer mechanism 2 is basically longitudinal. However, the traditional connection method of the anti-collision plate and multiple groups of springs is difficult to ensure that the impact direction is basically longitudinal. In most cases, the impact direction will be at a certain angle to the longitudinal direction, thereby affecting the elasticity and service life of the spring. Therefore, the collision buffer device of the utility model can effectively ensure that the impact direction of the mounting frame 1 and the buffer mechanism 2 is basically longitudinal, so that the compression direction of each elastic component is basically along the longitudinal direction, thereby ensuring the elastic performance of each elastic component when the collision forces in various directions collide, and realizing effective buffering of the collision force; and each elastic component is not easy to deform, which extends the service life of each elastic component.

[0067] Secondly, the buffer mechanism 2 also includes a plurality of buffer springs 24; the plurality of buffer springs 24 are arranged in an array between the mounting frame 1 and the anti-collision plate 21. In this embodiment, the longitudinal cross-section of the buffer spring 24 is arc-shaped, and the arc-shaped structure makes the buffer spring 24 have a certain elasticity, and the two free ends of the buffer spring 24 are connected to the mounting frame 1 by screw connection. Specifically, when the anti-collision plate 21 moves longitudinally toward the roller 4, excessive impact force will cause the anti-collision plate 21 to squeeze the plurality of buffer springs 24, which not only effectively protects the anti-collision plate 21, but also realizes the four-level buffering of the collision buffer device through the plurality of buffer springs 24, further improving the buffering performance of the collision buffer device, so that the collision buffer device can adapt to a larger impact load, and improves the driving safety of the highway bridge.

[0068] In addition, the collision buffer device further comprises a rubber strip 5; the rubber strip 5 is arranged on the mounting frame 1 and is located directly above and / or directly below the roller 4. Figure 2 Taking the orientation shown as an example, the left end point of the rubber strip 5 and the left end point of the plurality of rollers 4 are located in the same vertical plane. Since the anti-collision plate 21 abuts against the plurality of rollers 4 under the action of the buffer spring 23, the anti-collision plate 21 may be damaged through the rollers 4 due to excessive impact force. By arranging the impact end faces of the rubber strip 5 and the plurality of rollers 4 in the same vertical plane, when the rollers 4 are deformed concavely, that is, when the rollers 4 are hit into the interior of the mounting frame 1 by a vehicle, the rubber strip 5 can buffer the vehicle and prevent the vehicle from damaging the anti-collision plate 21 after the rollers 4 fail.

[0069] See also Figure 4The clamping ring mechanism 3 also includes a clamping ring 32 and an adjusting bolt 33; the adjusting bolt 33 is threadedly connected to the hinge ring 31; the clamping ring 32 is arranged in the hinge ring 31, and the adjusting bolt 33 is rotatably connected to the clamping ring 32; the opening of the clamping ring 32 faces the mounting frame 1. Since the closed loop size of the hinge ring 31 is fixed, it can only be installed with railings of corresponding sizes. Therefore, the clamping ring 32 and the adjusting bolt 33 are added to adjust the clamping aperture of the clamping ring mechanism 3 to improve the installation adaptability of the clamping ring mechanism 3 to railings of different sizes. Specifically, by screwing the adjusting bolt 33, the clamping ring 32 can be driven to move longitudinally to adjust the spacing between the clamping ring 32 and the inner wall of the hinge ring 31, so that the railing can be clamped between the clamping ring 32 and the hinge ring 31, and flexible installation on railings of different sizes can be achieved.

[0070] Furthermore, the clamping ring mechanism 3 further includes a support ring 37 and a compression spring 34; the opening of the support ring 37 faces the opening of the clamping ring 32; one end of the compression spring 34 is connected to the hinge ring 31, and the other end is connected to the support ring 37. In this embodiment, the railing is clamped between the support ring 37 and the clamping ring 32. Compared with the embodiment in which the railing is clamped between the clamping ring 32 and the hinge ring 31, the contact area between the railing and the support ring 37 is larger and the force is more stable in this embodiment; and the setting of the compression spring 34 enables the support ring 37 to move longitudinally, and cooperate with the clamping ring 32 to achieve stable clamping of railings of different sizes.

[0071] Secondly, the opening of the support ring 37 and the opening of the clamping ring 32 are both provided with anti-skid pads 35. The anti-skid pads 35 can enhance the friction between the support ring 37 (and the clamping ring 32) and the railing, and further improve the connection stability between the clamping ring mechanism 3 and the guardrail 7. The specific number of the clamping ring mechanism 3 can be set according to actual needs.

[0072] In addition, the clamping ring mechanism 3 also includes a connecting block 36 and a damper; a damping spring 6 is provided on the mounting frame 1; the free end of the damping spring 6 is connected to the connecting block 36; and a damper is provided inside the damping spring 6. The damping spring 6 performs three-level buffering for the collision buffer device. The damper is built into the damping spring 6, so that the damping spring 6 has both buffering and shock absorbing functions. Optionally, a damper is also provided inside the buffer spring 23.

[0073] Furthermore, the mounting frame 1 is provided with a fixing block 11; the fixing block 11 is provided with a guide groove; the shock absorbing spring 6 is built into the guide groove; and the connecting block 36 is connected to the guide groove in a longitudinal sliding manner. The connecting block 36 slides inside the fixing block 11, and on the basis of the damper, the transmission stability of the mounting frame 1 and the clamping ring mechanism 3 is further improved. The fixing block 11 is effectively supported and guided in sliding by the connecting block 36, so that the longitudinal load of the impact force impacts along the axial direction of the shock absorbing spring 6, effectively protecting the damper and the shock absorbing spring 6, so that the two can efficiently complete the three-level buffering.

[0074] Secondly, the mounting frame 1 includes a support plate 12 and a pair of buffer plates 13; the pair of buffer plates 13 are arranged at the top and bottom ends of the support plate 12 in a one-to-one correspondence, and the three are arranged in a concave shape; the two free ends of the rollers 4 are rotatably connected to the pair of buffer plates 13 in a one-to-one correspondence; the buffer mechanism 2 is slidably connected to the pair of buffer plates 13 along the longitudinal direction; the clamping ring mechanism 3 is arranged on the side of the support plate 12 away from the buffer mechanism 2. Specifically, the concave shape is also an I-shaped plate, and the I-shaped plate structure can effectively ensure the structural strength of the mounting frame 1 and stably transfer the load. The buffer mechanism 2 is arranged between the multiple rollers 4 and the support plate 12, so that the buffer mechanism 2 does not directly contact and collide with the vehicle, which effectively protects the buffer mechanism 2.

[0075] It should be understood that the above description of the specific embodiments of the utility model is only for illustrating the technical route and features of the utility model, and its purpose is to enable those skilled in the art to understand the content of the utility model and implement it accordingly, but the utility model is not limited to the above specific implementation methods. All changes or modifications made within the scope of the claims of the utility model should be included in the protection scope of the utility model.

Claims

1. A collision buffer device for a highway bridge, characterized in that: The collision buffer device comprises a mounting frame (1), a buffer mechanism (2), a clamping ring mechanism (3) and a plurality of rollers (4); One end surface of the mounting frame (1) is connected to the clamping ring mechanism (3), and the other end surface is rotatably connected to a plurality of rollers (4); the plurality of rollers (4) are arranged in a transverse array; The buffer mechanism (2) is built into the mounting frame (1), and the buffer mechanism (2) is capable of elastically sliding in the longitudinal direction within the mounting frame (1); The clamping ring mechanism (3) comprises a hinged ring (31) and a fixing bolt (311); the free end of the hinged ring (31) is detachably connected to the fixing bolt (311); and the hinged ring (31) is elastically connected to the mounting frame (1).

2. The collision buffer device for a highway bridge according to claim 1, characterized in that: The buffer mechanism (2) comprises an anti-collision plate (21), a pair of sliders (22) and a pair of buffer springs (23); The top end and the bottom end of the inner wall of the mounting frame (1) are provided with corresponding sliding grooves; The slider (22) is connected to the slide groove in a sliding manner along the longitudinal direction; one end of the buffer spring (23) is connected to the slide groove, and the other end is connected to the slider (22); The top end and the bottom end of the anti-collision plate (21) are correspondingly connected to a pair of sliding blocks (22).

3. The collision buffer device for a highway bridge according to claim 2, characterized in that: The buffer mechanism (2) further comprises a plurality of buffer springs (24); A plurality of buffer spring sheets (24) are arranged in an array between the mounting frame (1) and the anti-collision plate (21).

4. The collision buffer device for a highway bridge according to any one of claims 1 to 3, characterized in that: The collision buffer device also includes a rubber strip (5); The rubber strip (5) is arranged on the mounting frame (1) and is located directly above and / or directly below the roller (4).

5. The collision buffer device for a highway bridge according to any one of claims 1 to 3, characterized in that: The clamping ring mechanism (3) also includes a clamping ring (32) and an adjusting bolt (33); The adjusting bolt (33) is threadedly connected to the hinge ring (31); The clamping ring (32) is arranged inside the hinge ring (31), and the adjusting bolt (33) is rotatably connected to the clamping ring (32); the opening of the clamping ring (32) faces the mounting frame (1).

6. The collision buffer device for a highway bridge according to claim 5, characterized in that: The clamping ring mechanism (3) further comprises a supporting ring (37) and a pressing spring (34); The opening of the support ring (37) faces the opening of the clamping ring (32); One end of the extrusion spring (34) is connected to the hinge ring (31), and the other end is connected to the support ring (37).

7. The collision buffer device for a highway bridge according to claim 6, characterized in that: The opening of the support ring (37) and the opening of the clamping ring (32) are both provided with anti-slip pads (35).

8. The collision buffer device for a highway bridge according to any one of claims 1 to 3, characterized in that: The clamping ring mechanism (3) further comprises a connecting block (36) and a damper; the mounting frame (1) is provided with a shock absorbing spring (6); The free end of the shock absorbing spring (6) is connected to the connecting block (36); the damper is arranged inside the shock absorbing spring (6).

9. The collision buffer device for a highway bridge according to claim 8, characterized in that: The mounting frame (1) is provided with a fixing block (11); The fixing block (11) is provided with a guide groove; the shock absorbing spring (6) is built into the guide groove; The connecting block (36) is slidably connected to the guide groove along the longitudinal direction.

10. The collision buffer device for a highway bridge according to any one of claims 1 to 3, characterized in that: The mounting frame (1) comprises a support plate (12) and a pair of buffer plates (13); A pair of buffer plates (13) are arranged one-to-one at the top and bottom ends of the support plate (12), and the three are arranged in a concave shape; The two free ends of the roller (4) are rotatably connected to a pair of buffer plates (13) in a one-to-one correspondence; The buffer mechanism (2) is slidably connected to a pair of buffer plates (13) along the longitudinal direction; The clamping ring mechanism (3) is arranged on a surface of the support plate (12) facing away from the buffer mechanism (2).

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