Rolling hinge support and fixed hinge support matched therewith

Abstract

The application discloses a rolling hinge support and a fixed hinge support matched with the rolling hinge support, wherein the rolling hinge support comprises a rolling upper support and a rolling lower support, a rolling support is arranged between the rolling upper support and the rolling lower support, and the rolling support is adapted to the transverse displacement of the rolling upper support relative to the rolling lower support through deflection; deflection limiting upper plates are fixedly arranged on the rolling upper support, at least two upper bolt assemblies are jointly arranged between the two deflection limiting upper plates and the rolling support, and the rolling support is provided with upper bolt through holes; deflection limiting lower plates are fixedly arranged on the rolling lower support, at least two lower bolt assemblies are jointly arranged between the two deflection limiting lower plates and the rolling support, and the rolling support is provided with lower bolt through holes; the proximal sides of the upper bolt through holes and the lower bolt through holes are respectively formed into arc-shaped rolling sides, and the distal sides of the upper bolt through holes and the lower bolt through holes are respectively formed into arc-shaped avoiding sides. The application has good durability, reliable connection, good overturning resistance and good lateral resistance.

Description

Technical Field

[0001] This invention relates to the field of bridge or building beam connection support technology, and in particular to a rolling hinge support and a fixed hinge support used in conjunction with it. Background Technology

[0002] Currently, bridge and building beams are connected to the underlying columns and other structures using bearings. These bearings serve to transfer loads and accommodate the expansion and contraction of the beam, making them an important component of bridge and building beam structures. Currently, sliding bearings are commonly used for connecting bridge and building beams. Figure 11 As shown, in this sliding support, the upper support base plate and the upper side baffle, and the lower support base plate and the lower side baffle respectively form rectangular slots. A rubber pad composed of a rubber plate and a steel pad is placed in the slot. A stainless steel pad is placed below the rubber pad, and a polytetrafluoroethylene plate with a low coefficient of friction is placed at the stainless steel pad. This sliding support relies on the relative sliding between the polytetrafluoroethylene plate and the base plate to adapt to the displacement caused by the expansion and contraction of the beam.

[0003] However, this type of sliding bearing still has some problems in use. First, under the long-term action of large pressure and horizontal displacement deformation, this sliding bearing is prone to aging and failure, requiring regular replacement, which is time-consuming and labor-intensive, affecting the normal use of the beam. Second, this sliding bearing cannot restrict lateral displacement or guarantee lateral force, requiring additional lateral force-bearing devices. Third, this sliding bearing lacks anti-overturning measures and cannot provide anti-overturning tensile force, resulting in a high risk of overturning when the beam is subjected to large eccentric load pressure. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a rolling hinge support with good durability, reliable connection, and good anti-overturning and anti-lateral capabilities, and a fixed hinge support used in conjunction with it.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is: a rolling hinge support, comprising an upper rolling support fixedly connected to a beam and a lower rolling support fixedly connected to a column, wherein a rolling support member is provided between the upper rolling support and the lower rolling support, and the rolling support member is deflected to adapt to the lateral displacement of the upper rolling support relative to the lower rolling support.

[0006] The rolling upper support is fixedly provided with deflection limiting upper plates in two directions of the deflection of the rolling support member. At least two upper bolt assemblies are connected between the two deflection limiting upper plates and the rolling support member. The rolling support member is provided with upper bolt through holes corresponding to the upper bolt assemblies.

[0007] The rolling lower support is fixedly provided with deflection limiting lower plates in two directions of the deflection of the rolling support member. At least two lower bolt assemblies are connected between the two deflection limiting lower plates and the rolling support member. The rolling support member is provided with lower bolt through holes corresponding to the lower bolt assemblies.

[0008] The upper bolt through hole and the lower bolt through hole are respectively formed on their near sides to form arc-shaped rolling sides that cause the rolling support to roll and deflect. The upper bolt through hole and the lower bolt through hole are respectively formed on their far sides to form arc-shaped avoidance sides that adapt to the deflection of the rolling support.

[0009] As a preferred technical solution, the rolling upper support is fixedly provided with a side resistance upper end plate that is fixedly connected to the left and right ends of the two deflection limiting upper plates respectively.

[0010] As a preferred technical solution, the rolling lower support is fixedly provided with a side resistance lower end plate that is fixedly connected to the left and right ends of the two deflection limiting lower plates respectively.

[0011] As a preferred technical solution, the two deflection limiting upper plates are arranged obliquely from top to bottom, gradually moving away from the rolling support.

[0012] As a preferred technical solution, the two deflection limiting lower plates are arranged obliquely from bottom to top, gradually moving away from the rolling support.

[0013] As a preferred technical solution, the upper and lower surfaces of the rolling support are respectively formed as arc surfaces.

[0014] A fixed hinge support used in conjunction with the aforementioned rolling hinge support includes a fixed upper support fixedly connected to a beam and a fixed lower support fixedly connected to a column. A fixed support plate extending to the fixed upper support is fixedly provided on the fixed lower support. Two undulating limiting plates are provided on the fixed upper support along the deflection direction of the rolling support. The fixed support plate is located between the two undulating limiting plates. At least two fixed side bolt assemblies are installed through the two undulating limiting plates and the fixed support plate.

[0015] As a preferred technical solution, an undulation adaptation gap is provided between the undulation limiting plate and the fixed support plate, and the fixed side bolt assembly is clearance-fitted with the fixed support plate and / or the undulation limiting plate.

[0016] As a preferred technical solution, the two undulating limiting plates are respectively provided with undulating limiting inclined surfaces that gradually move away from the fixed support plate from top to bottom on their near-side surfaces.

[0017] As a preferred technical solution, the fixed upper support is fixedly provided with side resistance end plates that are respectively fixedly connected to the left and right ends of the two undulating limiting plates.

[0018] Due to the adoption of the above technical solution, in the rolling hinge support of the present invention, the deflection of the rolling support member adapts to the displacement caused by the expansion and contraction of the beam. The deflection process relies on the arc-shaped rolling side to form a rolling change, resulting in low friction and good adaptability to the expansion and contraction of the beam. The rolling support member is rigidly connected by bolt assemblies and deflection limiting plates, ensuring reliable connection and good durability. Both upper and lower deflection limiting plates are connected at least at two points by at least two bolt assemblies, which provides strong anti-overturning tensile force and lateral resistance, ensuring that the upper and lower rolling supports will not detach. In the fixed hinge support, the fixed support plate and the two undulating limiting plates form a rigid constraint on that end of the beam, so that when the beam expands and contracts, the deflection of the rolling support member mainly occurs at the rolling hinge support, thus forming a matching system to ensure the stability of the beam. The fixed hinge support also uses multi-point bolt connections, achieving strong anti-overturning tensile force and lateral resistance while ensuring reliable connection and good durability. Attached Figure Description

[0019] The following figures are intended only to illustrate and explain the present invention and do not limit the scope of the invention. Wherein:

[0020] Figure 1 This is a schematic diagram of the structure of the rolling hinge support according to an embodiment of the present invention;

[0021] Figure 2 yes Figure 1 A schematic diagram of the AA structure;

[0022] Figure 3 yes Figure 1 Schematic diagram of BB structure;

[0023] Figure 4 yes Figure 1 Diagram showing the state of the rolling support when it deflects to its limit;

[0024] Figure 5 This is a schematic diagram of the structure of the fixed hinge support according to an embodiment of the present invention;

[0025] Figure 6 yes Figure 5 A schematic diagram of the CC structure;

[0026] Figure 7 yes Figure 5 Schematic diagram of DD structure;

[0027] Figure 8 yes Figure 5 EE structure diagram;

[0028] Figure 9 This is a schematic diagram illustrating the application principle of the rolling hinge support and the fixed hinge support according to an embodiment of the present invention.

[0029] Figure 10 yes Figure 9 Diagram showing the beam after expansion;

[0030] Figure 11 This is a schematic diagram of the structure of a sliding support in the prior art.

[0031] In the diagram: 1-Rolling upper support; 11-Deflection limit upper plate; 12-Upper bolt assembly; 121-Upper connecting stud; 122-Upper connecting nut; 13-Side resistance upper end plate; 14-Upper bolt mounting plate; 2-Rolling lower support; 21-Deflection limit lower plate; 22-Lower bolt assembly; 221-Lower connecting stud; 222-Lower connecting nut; 23-Side resistance lower end plate; 24-Lower bolt mounting plate; 3-Rolling support; 31-Upper bolt through hole; 32-Lower bolt through hole; 33- 34-Arc-shaped rolling side; 4-Arc-shaped clearance side; 4-Fixed upper support; 41-Irregular limiting plate; 411-Irregular limiting inclined surface; 42-Fixed side bolt assembly; 43-Irregular adaptation gap; 44-Side resistance end plate; 5-Fixed lower support; 51-Fixed support plate; 81-Upper support base plate; 82-Upper side baffle; 83-Lower support base plate; 84-Lower side baffle; 85-Rubber plate; 86-Steel pad plate; 87-Stainless steel pad plate; 88-PTFE plate; 91-Beam; 92-Column. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the following detailed description, exemplary embodiments of the invention are described only by way of illustration. It will be readily apparent to those skilled in the art that various modifications can be made to the described embodiments without departing from the spirit and scope of the invention. Therefore, the drawings and description are illustrative in nature and not intended to limit the scope of the claims.

[0033] like Figure 9 and Figure 10 As shown, a rolling hinge support includes an upper rolling support 1 fixedly connected to a beam 91 and a lower rolling support 2 fixedly connected to a column 92. A rolling support 3 is provided between the upper rolling support 1 and the lower rolling support 2. The rolling support 3 is deflected to accommodate the lateral displacement of the upper rolling support 1 relative to the lower rolling support 2. With the upper rolling support 1 fixedly connected to the beam 91 and the lower rolling support 2 fixedly connected to the column 92, the rolling support 3 is equivalent to deflecting to accommodate the displacement caused by the expansion and contraction of the beam 91.

[0034] like Figures 1 to 4As shown, the rolling upper support 1 is fixedly provided with deflection limiting upper plates 11 in two directions of deflection of the rolling support 3. At least two upper bolt assemblies 12 are connected between the two deflection limiting upper plates 11 and the rolling support 3. The rolling support 3 is provided with upper bolt through holes 31 corresponding to the upper bolt assemblies 12. The rolling support 3 is rigidly connected to the rolling upper support 1 by at least two upper bolt assemblies 12, which ensures reliable connection and good durability.

[0035] The rolling lower support 2 is fixedly provided with deflection limiting lower plates 21 in two directions of deflection of the rolling support 3. At least two lower bolt assemblies 22 are connected between the two deflection limiting lower plates 21 and the rolling support 3. The rolling support 3 is provided with lower bolt through holes 32 corresponding to the lower bolt assemblies 22. The rolling support 3 and the rolling lower support 2 are also rigidly connected by at least two lower bolt assemblies 22, which ensures reliable connection and good durability.

[0036] The aforementioned multiple bolt assemblies create at least four rigid connections between the upper rolling support 1 and the lower rolling support 2, providing strong resistance to overturning tension and lateral resistance, ensuring that the upper rolling support 1 and the lower rolling support 2 will not detach. Preferably, the upper rolling support 1 is fixedly provided with a side-resistance upper end plate 13, which is fixedly connected to the left and right ends of the two deflection limiting upper plates 11, respectively. The side-resistance upper end plate 13, together with the two deflection limiting upper plates 11, forms a box shape, improving structural strength and ensuring a reliable connection between the rolling support 3 and the upper rolling support 1. Furthermore, it resists lateral forces, further enhancing the upper rolling support 1's resistance to lateral forces. Similarly, the lower rolling support 2 is fixedly provided with a side-resistance lower end plate 23, which is fixedly connected to the left and right ends of the two deflection limiting lower plates 21, respectively.

[0037] In this embodiment, "left" and "right" are defined in the width direction of beam 91, respectively, in order to more clearly explain the structural principle of this embodiment, and not to limit the scope of protection.

[0038] The upper bolt through-hole 31 and the lower bolt through-hole 32 are respectively formed with arc-shaped rolling sides 33 to allow the rolling support 3 to roll and deflect. Thus, when the rolling support 3 deflects, rolling contact is formed between the rolling support 3 and both the upper bolt assembly 12 and the lower bolt assembly 22, resulting in low friction. This embodiment exhibits good adaptability to the expansion and contraction of the beam 91. The upper bolt through-hole 31 and the lower bolt through-hole 32 are respectively formed with arc-shaped clearance sides 34 to accommodate the deflection of the rolling support 3.

[0039] Preferably, the upper and lower ends of the rolling support 3 are respectively formed as arc surfaces. This arc surface design prevents the rolling support 3 from rigidly interfering with the upper rolling support 1 and the lower rolling support 2 during the deflection and rolling process. This ensures both the smoothness of the rolling support 3's deflection and rolling process and prevents the beam 91 from easily shifting vertically during the deflection and rolling process, thus ensuring the stability of the beam 91.

[0040] Preferably, the arc surface is centered on the axis of rotation of the rolling support 3, meaning the radius of the arc surface is the distance from the axis to the corresponding end. Based on this configuration, the height of the rolling support 3 can be set to be equal to the distance between the upper rolling support 1 and the lower rolling support 2. Thus, the rolling support 3 forms a direct support between the upper rolling support 1 and the lower rolling support 2, which, together with the upper bolt assembly 12 and the lower bolt assembly 22, creates a more reliable support capability.

[0041] Preferably, the two deflection limiting upper plates 11 are arranged obliquely from top to bottom, gradually moving away from the rolling support member 3, so that when the rolling support member 3 deflects to its extreme position, the corresponding deflection limiting upper plate 11 can form surface contact with the rolling support member 3, ensuring the limiting effect and reducing structural deformation. Similarly, the two deflection limiting lower plates 21 are arranged obliquely from bottom to top, gradually moving away from the rolling support member 3.

[0042] The upper bolt assembly 12 of this embodiment includes an upper connecting stud 121 that penetrates both deflection limiting upper plates 11 and the rolling support 3. Upper connecting nuts 122 are respectively installed at the ends of the upper connecting stud 121 extending out of the two deflection limiting upper plates 11. The lower bolt assembly 22 includes a lower connecting stud 221 that penetrates both deflection limiting lower plates 21 and the rolling support 3. Lower connecting nuts 222 are respectively installed at the ends of the lower connecting stud 221 extending out of the two deflection limiting lower plates 21.

[0043] Accordingly, in this embodiment, an upper bolt mounting plate 14 is fixedly welded to the side of each deflection limiting upper plate 11 away from the rolling support 3, so as to form a plane that can fully contact the tightening position of the upper connecting nut 122, ensuring the tightening effect of the upper bolt assembly 12 between the two deflection limiting upper plates 11. Similarly, a lower bolt mounting plate 24 is fixedly welded to the side of each deflection limiting lower plate 21 away from the rolling support 3.

[0044] like Figures 5 to 8As shown, the fixed hinge support used in conjunction with the rolling hinge support includes a fixed upper support 4 fixedly connected to the beam 91 and a fixed lower support 5 fixedly connected to the column 92. A fixed support plate 51 extending to the fixed upper support 4 is fixedly provided on the fixed lower support 5. Two undulating limiting plates 41 are provided on the fixed upper support 4 along the deflection direction of the rolling support 3. The fixed support plate 51 is located between the two undulating limiting plates 41. At least two fixed side bolt assemblies 42 are installed through the two undulating limiting plates 41 and the fixed support plate 51.

[0045] The fixed hinge support rigidly restricts the displacement of the beam 91 at this end in the expansion and contraction direction through the two undulating limiting plates 41 and the fixed support plate 51. This ensures that when the beam 91 expands or contracts, the rolling support 3 mainly deflects at the rolling hinge support, thus ensuring the stability of the beam 91. The fixed upper support 4 and the fixed lower support 5 are also fixedly connected to the fixed lower support 5 by at least two bolt assemblies and the fixed support plate 51, achieving reliable connection, good durability, and strong resistance to overturning tensile forces and lateral resistance. The structure of the fixed side bolt assembly 42 is the same as that of the upper bolt assembly 12 and the lower bolt assembly 22, and will not be described again here.

[0046] Preferably, an undulation-adapting gap 43 is provided between the undulation limiting plate 41 and the fixed support plate 51, and the fixed side bolt assembly 42 is clearance-fitted with the fixed support plate 51 and / or the undulation limiting plate 41. With this arrangement, the undulation limiting plate 41 can generate a certain pitch amplitude relative to the fixed support plate 51, which can adapt to the slight undulations generated at that end of the beam 91 during the deflection of the rolling support 3, reducing structural jamming and further improving the rapid adaptation of the beam 91 to expansion and contraction in this embodiment.

[0047] In this embodiment, the two undulating limiting plates 41 are respectively provided with undulating limiting inclined surfaces 411 that gradually move away from the fixed support plate 51 from top to bottom on their near-side surfaces. The gap between the undulating limiting inclined surface 411 and the fixed support plate 51 constitutes the undulating adaptation gap 43. Of course, the undulating limiting plate 41 can also be an inclined plate that gradually moves away from the fixed support plate 51 from top to bottom. This is a variation of equivalent technical means and should also be within the protection scope of this invention.

[0048] The fixed upper support 4 is fixedly provided with a side resistance end plate 44, which is fixedly connected to the left and right ends of the two undulating limiting plates 41 respectively. Through the side resistance end plate 44, the structural strength is improved, and the resistance to lateral forces at the fixed hinge support is also improved.

[0049] The following application examples at the rolling hinge support further illustrate the specific implementation of this embodiment.

[0050] The linear expansion coefficient α of concrete c 1*10 -5 / ℃, with an initial temperature of 20℃. When beam 91 is heated to 70℃, the expansion of the 80m (i.e., 80000mm) beam 91 is: 80000*(70-20)℃*1*10 -5 / ℃=40mm. When beam 91 cools to -30℃, the shrinkage of the 80m (i.e., 80000mm) beam 91 is: 80000*(20+30)℃*1*10 -5 / ℃=40mm. In actual implementation, the rolling support 3 is designed to accommodate the extreme expansion and contraction of the temperature from -30℃ to 70℃ when it deflects in any direction at the middle position, which is 40+40=80mm.

[0051] The dimensions of other structural components in this application example are as follows: the distance between the upper rolling support 1 and the lower rolling support 2 is 400mm; the thickness of the upper rolling support 1 and the lower rolling support 2 is 25mm; the thickness of the upper side resist plate 13 and the lower side resist plate 23 is 25mm; the width of the rolling support 3 is 400mm, the thickness is 120mm, and the height is 400mm, and the rolling support 3 is designed as a symmetrical structure with both its upper and lower end faces forming arc surfaces with a radius of 200mm; the diameter of the upper bolt through hole 31 and the lower bolt through hole 32 is 45mm; the upper connecting stud 121 and the lower connecting stud 221 are M42 studs. The design value of the compressive strength of the steel is 290N / mm². 2 The design value for shear strength is 170 N / mm². 2 .

[0052] When the rolling support 3 deflects to adapt to the aforementioned 80mm limit expansion / contraction, such as Figure 4 As shown, the deflection angle of the rolling support 3 is approximately: arcsin(80 / 400)≈11.5°.

[0053] At this time, as Figure 4 As shown, the contact width w between the rolling support 3 and the upper rolling support 1 and the lower rolling support 2 is approximately 38 mm (120*cos11.5° - 400*sin11.5°). The supporting force provided by the rolling support 3 is (38*400 - 38*45*2)*290 = 3416200 N = 3416.2 kN. The overturning tensile force provided by the upper bolt assembly 12 and the lower bolt assembly 22 is:

[0054] 3.14*21*21*170*2*2=941623N≈942kN. The lateral resistance provided by the upper side resistance plate 13 and the lower side resistance plate 23 is: 25*400*170*2=3400000N=3400kN. For the pressure, overturning force, lateral force, etc. that may be generated on the beam 91 by vehicles, etc., the supporting force, anti-overturning force and anti-lateral force provided by the above rolling hinge support are undoubtedly more than sufficient.

[0055] In summary, in this embodiment of the rolling hinge support, the deflection of the rolling support 3 adapts to the displacement caused by the expansion and contraction of the beam 91. The deflection process relies on the rolling change formed by the arc-shaped rolling side 33, resulting in low friction and good adaptability to the expansion and contraction of the beam 91. The rolling support 3 is rigidly connected by bolt assemblies and deflection limiting plates, ensuring reliable connection and good durability. The two upper deflection limiting plates 11 and the two lower deflection limiting plates 21 are connected at least at two points by at least two bolt assemblies, providing strong resistance to overturning tension and lateral resistance, ensuring that the upper rolling support 1 and the lower rolling support 2 will not detach. This embodiment further adds a lateral resistance end plate 44, which increases structural strength and further enhances lateral resistance. In the fixed hinge support, the fixed support plate 51 and the two undulation limiting plates 41 form a rigid constraint on that end of the beam 91, so that when the beam 91 expands or contracts, the rolling support 3 mainly deflects at the rolling hinge support, thus forming a matching system to ensure the stability of the beam 91. An undulation adaptation gap 43 is provided between the two undulation limiting plates 41 and the fixed support plate 51, and the fixed side bolt assembly 42 is installed with a clearance fit, allowing the fixed hinge support to adapt to the slight undulations of that end of the beam 91 when the rolling support 3 deflects, preventing jamming and reducing structural deformation. The fixed hinge support also uses multi-point bolt connections, ensuring reliable connection and good durability while achieving strong resistance to overturning tensile forces and lateral resistance.

[0056] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A rolling hinge support, comprising an upper rolling support fixedly connected to a beam and a lower rolling support fixedly connected to a column, characterized in that: A rolling support is provided between the upper rolling support and the lower rolling support, and the rolling support is deflected to accommodate the lateral displacement of the upper rolling support relative to the lower rolling support. The rolling upper support is fixedly provided with deflection limiting upper plates in two directions of the deflection of the rolling support member. At least two upper bolt assemblies are connected between the two deflection limiting upper plates and the rolling support member. The rolling support member is provided with upper bolt through holes corresponding to the upper bolt assemblies. The rolling lower support is fixedly provided with deflection limiting lower plates in two directions of the deflection of the rolling support member. At least two lower bolt assemblies are connected between the two deflection limiting lower plates and the rolling support member. The rolling support member is provided with lower bolt through holes corresponding to the lower bolt assemblies. The upper bolt through hole and the lower bolt through hole are respectively formed on their near sides to form arc-shaped rolling sides that cause the rolling support to roll and deflect. The upper bolt through hole and the lower bolt through hole are respectively formed on their far sides to form arc-shaped clearance sides that adapt to the deflection of the rolling support. The two deflection limiting plates are arranged at an angle, gradually moving away from the rolling support from top to bottom; the upper and lower surfaces of the rolling support are respectively formed as arc surfaces.

2. A rolling hinge support as described in claim 1, characterized in that: The rolling upper support is fixedly provided with a side resistance upper end plate that is fixedly connected to the left and right ends of the two deflection limiting upper plates respectively.

3. A rolling hinge support as described in claim 1, characterized in that: The rolling lower support is fixedly provided with a side resistance lower end plate that is fixedly connected to the left and right ends of the two deflection limiting lower plates, respectively.

4. A rolling hinge support as described in claim 1, characterized in that: The two deflection limiting plates are arranged obliquely from bottom to top, gradually moving away from the rolling support.

5. A fixed hinge support for use with a rolling hinge support as described in any one of claims 1 to 4, comprising a fixed upper support fixedly connected to the beam and a fixed lower support fixedly connected to the column, characterized in that: The fixed lower support is fixedly provided with a fixed support plate extending to the fixed upper support. The fixed upper support is provided with two undulating limiting plates along the deflection direction of the rolling support. The fixed support plate is located between the two undulating limiting plates. At least two fixed side bolt assemblies are installed through the two undulating limiting plates and the fixed support plate.

6. The fixed hinge support as described in claim 5, characterized in that: An undulation adaptation gap is provided between the undulation limiting plate and the fixed support plate, and the fixed side bolt assembly is clearance-fitted with the fixed support plate and / or the undulation limiting plate.

7. The fixed hinge support as described in claim 6, characterized in that: The two undulating limiting plates are respectively provided with undulating limiting inclined surfaces that gradually move away from the fixed support plate from top to bottom on their near side surfaces.

8. The fixed hinge support as described in claim 5, characterized in that: The fixed upper support is fixedly provided with side resistance end plates that are respectively fixedly connected to the left and right ends of the two undulating limiting plates.

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