Paddle clamp device

Abstract

The invention relates to a paddle clamp device which comprises a paddle clamp provided with a pin shaft bin; the two paddle bodies are respectively connected with the paddle clamp, so that the two paddle bodies are symmetrically arranged along the first axis; a torsion angle is formed from the blade tip to the root of the blade body; the fixed seat is provided with a pin shaft hole; the connecting pin shaft penetrates through the pin shaft bin and the pin shaft hole, so that the paddle clamp is rotationally connected with the fixed seat; and the axis of the connecting pin shaft is crossed with the first axis, so that the torsion angle is increased when the paddle body deflects downwards. The blade body can be driven to be automatically corrected in the direction opposite to the deflection direction, the flapping degree is reduced, and the stability in the flight process is improved.

Description

Technical Field

[0001] The present application relates to the technical field of propeller clamps, and in particular to a propeller clamp device. Background Art

[0002] During flight, the propeller blades of a seesaw-style propeller clamp are affected by the airflow, causing them to yaw and flap. For example, during forward flight, the blade on the side rotating forward has a higher speed relative to the air and generates more lift. The blade on the other side rotating backward has a lower speed relative to the air and generates less lift, causing the backward blade to yaw downward about the horizontal axis. Moderate flapping motion can improve stability, but excessive flapping can lead to aerodynamic imbalance, making it easy to lose control and cause a roll, especially in unstable airflow.

[0003] Therefore, it is necessary to provide a propeller clamp device that can automatically perform balance correction when the propeller blade deflects. Summary of the Invention

[0004] Based on this, it is necessary to provide a paddle clamp device, and its specific technical solution is as follows.

[0005] A paddle clamp device, comprising: Oar clamp, equipped with a pin shaft warehouse; The two blade bodies are respectively connected to the blade clamps so that the two blade bodies are symmetrically arranged along the first axis; the blade bodies form a torsion angle from the tip to the root; The fixing seat is provided with a pin hole; The connecting pin passes through the pin shaft bin and the pin shaft hole, so that the propeller clamp is rotatably connected to the fixing seat; the axis of the connecting pin shaft is arranged crosswise with the first axis, so that the torsion angle increases when the propeller body deflects downward.

[0006] Furthermore, the axis of the connecting pin is arranged to cross the first axis to form an angle of 5° to 10°.

[0007] Furthermore, the oar clamp includes an oar clamp upper cover, an oar clamp base and a blade connector; the blade body is clamped between the oar clamp upper cover and the oar clamp base; the blade connector connects the oar clamp base, the blade body and the oar clamp upper cover into one.

[0008] Furthermore, the connecting pin includes a short pin, a long pin and a pin fastener; the short pin is inserted into the pin hole, the long pin passes through the pin bin and is plugged into the short pin; the pin fastener connects the long pin and the short pin.

[0009] Furthermore, it also includes a buffer assembly, which is installed on a fixed seat, and buffer parts are respectively provided at both ends of the buffer assembly; the paddle clamp is provided with two abutting ends corresponding to the two blade bodies respectively; the two abutting ends are respectively located on both sides of the buffer assembly; when the blade body on one side is deflected downward, the corresponding abutting end abuts against and squeezes the buffer part.

[0010] Furthermore, the buffer assembly includes an outer shell, a push pin and an elastic member; a push pin guide hole extending along a first direction is provided in the outer shell; push pins movable along the first direction are respectively provided at both ends of the push pin guide hole, and the push pins extend out of the push pin guide hole, and the push pins are used to abut against the abutting end; the elastic member is arranged between the two push pins and has elastic potential energy for driving the two push pins away from each other.

[0011] Furthermore, a movable groove is provided in the ejector pin, and the ejector pin limiting member is connected to the outer shell and inserted into the movable groove. The length of the movable groove is greater than the diameter of the ejector pin limiting member, and the ejector pin limiting member is used to limit the moving stroke of the ejector pin.

[0012] Furthermore, the oar clamp includes an oar clamp body and a rubber buffer pad; a groove is provided at the bottom of the oar clamp body, the rubber buffer pad is connected to the oar clamp body and abuts against the side wall of the groove; the side of the rubber buffer pad facing the ejector pin is the abutment end.

[0013] Furthermore, a rubber pad fixing portion is provided on the top of the rubber buffer pad, and a limit block is provided on the rubber pad fixing portion; a rubber pad fixing hole is provided on the paddle clamp body; after the rubber pad fixing portion passes through the fixing hole, the limit block is abutted against the paddle clamp body.

[0014] Furthermore, a special-shaped block is provided on a side of the rubber buffer pad away from the abutting end, and a special-shaped groove is provided on the side wall of the groove, and the special-shaped block is stuck in the special-shaped groove.

[0015] Beneficial effects: 1. The propeller clamp device provided by the present invention makes the two blade bodies symmetrical along the first axis, and makes the axis of the connecting pin shaft cross the first axis to form a certain angle, so that when the blade body is affected by the airflow and deflects around the connecting pin shaft, the torsion angle of the blade body that deflects downward increases, and the torsion angle of the blade body that deflects upward decreases. The increase in the torsion angle of the blade body on one side will increase the windward force area of ​​the blade body on this side, and the force on the blade body on this side will also be greater, thereby driving the blade body to automatically correct in the opposite direction of the deflection, reducing the degree of flapping, and improving stability during flight.

[0016] 2. The present invention provides a propeller clamp device. When the blade body on one side deflects downward, the buffer member abuts against the abutting end corresponding to the blade body on that side, providing a reverse force, which can reduce the degree of downward deflection of the blade body, thereby further automatically correcting the blade; and during the swinging of the blade body, the buffer member can play a buffering role, reducing the vibration of the fixing seat caused by the swinging of the blade body, thereby further improving stability during flight. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 It is a schematic elevation view of the paddle clamp device; Figure 2 This is an exploded diagram of the paddle clamp device; Figure 3 is a schematic cross-sectional view of the paddle clamp device along the plane where the axis of the connecting pin is located; Figure 4 An exploded diagram of the buffer assembly and the paddle clamp base; Figure 5 is a schematic diagram of a top pin; Figure 6 is a schematic diagram of a rubber buffer pad; Figure 7 It is a top view of the blade body in a balanced state; Figure 8 It is a side view of the blade body in a balanced state; Figure 9 is a cross-sectional view of the blade body in a balanced state; Figure 10 for Figure 9 A magnified schematic diagram of area A in the middle; Figure 11 A top view of one side of the blade body in a downward deflection state; Figure 12 This is a side view of the blade body on one side in the downward deflection state; Figure 13 This is a cross-sectional view of one side of the blade body in the downward deflection state; Figure 14 for Figure 13 Schematic diagram of the enlarged area B.

[0019] Description of reference numerals: 1. blade clamp; 2. blade body; 3. fixing seat; 4. connecting pin; 5. buffer assembly; 6. driving member; 11. Oar clamp cover; 12. Oar clamp base; 13. Propeller blade connector; 14. Propeller blade fastener; 15. Oar clamp fastener; 16. Rubber cushion; 111. Pin shaft compartment; 112. Upper cover screw hole; 121, base shaft hole; 161. Rubber pad fixing portion; 162. Limit block; 163. Special-shaped block; 21. First axis; 22. Connecting through hole; 23. Wear-resistant washer; 31. Pin hole; 32. Base fixing piece; 41. Short pin; 42. Long pin; 43. Pin fastener; 44. Bearing; 51. Outer shell; 52. Ejector pin; 53. Elastic member; 54. Ejector pin stopper; 511, ejector pin guide hole; 521. Activity slot. DETAILED DESCRIPTION

[0020] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0021] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0023] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0024] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0025] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0026] Example This embodiment provides a blade clamp device, comprising a blade clamp 1, a blade body 2, a fixing seat 3 and a connecting pin 4. Figure 1 As shown, the paddle clamp 1 is provided with a pin shaft bin 111, and the pin shaft bin 111 passes through the paddle clamp 1. The two blade bodies 2 are respectively connected to the paddle clamp 1, so that the two blade bodies 2 are symmetrically arranged along the first axis 21. The blade body 2 forms a torsion angle along the tip to the root. When the blade bodies 2 on both sides are in a balanced state without deflection, the torsion angles of the two blade bodies 2 are the same. A pin shaft hole 31 is provided on the fixing seat 3, and the fixing seat 3 is connected to the driving member 6 through the base fixing member 32. The connecting pin shaft 4 passes through the pin shaft bin 111 and the pin shaft hole 31, so that the paddle clamp 1 is rotatably connected to the fixing seat 3, and the fixing seat 3 is driven to rotate by the driving member 6, thereby driving the blade body 2 to rotate. The paddle clamp 1 and the blade body 2 can rotate around the axis of the connecting pin shaft 4 to generate deflection. Refer to Figure 3As shown, the axis of the connecting pin 4 is arranged to intersect with the first axis 21 , that is, the rotation axis of the blade body 2 intersects with the first axis 21 , so that the torsion angle increases when the blade body 2 deflects downward.

[0027] Reference Figure 7 and Figure 8 As shown in FIG, when the blade body 2 is in a balanced state without deflection, the torsion angles of the blade bodies 2 on both sides are both 9°. Figure 11 and Figure 12 As shown, when the blade body 2 on one side deflects downward and is in an unbalanced state, the blade body 2 deflects around the axis of the connecting pin 4, and the axis of the connecting pin 4 intersects with the first axis 21. Therefore, the torsion angle of the blade body 2 will change when it deflects, causing the torsion angle of the blade body 2 on the side that deflects downward to change to 10°. At this time, the torsion angles of the blade bodies 2 on both sides are different. Specifically, the torsion angle of the blade body 2 on the side that deflects downward is greater than the torsion angle of the blade body 2 on the other side. The increase in the torsion angle will increase the windward force area of ​​the blade body 2 on that side, and the force on the blade body 2 on that side will also be greater. Therefore, the lift force on the blade body 2 on the side that deflects downward is greater than the lift force on the blade body 2 on the other side, causing the blade body 2 to automatically correct in the opposite direction of the deflection.

[0028] The blade clamp device provided in this embodiment makes the two blade bodies 2 symmetrical along the first axis 21, and makes the axis of the connecting pin 4 cross the first axis 21 to form a certain angle, so that when the blade body 2 is affected by the airflow and deflects around the connecting pin 4, the torsion angle of the blade body 2 that deflects downward increases, and the torsion angle of the blade body 2 that deflects upward decreases. The increase in the torsion angle of the blade body 2 on one side will increase the windward force area of ​​the blade body 2 on that side, and the force on the blade body 2 on that side will also be greater, thereby driving the blade body 2 to automatically correct in the opposite direction of the deflection, reducing the degree of flapping, and improving stability during flight.

[0029] Specifically, in this embodiment, the axis of the connecting pin 4 intersects the first axis 21 to form an angle of 5° to 10°. This angle should not be too large or too small. If it is too large, the torsion angle of the blade bodies 2 on both sides may change significantly during the yaw process, affecting normal flight. If it is too small, the torsion angle will not change significantly, the windward force area will not change much, and the automatic balance correction effect will be poor. However, in other embodiments, the angle can also be set to other angles.

[0030] Specifically, refer to Figure 2As shown, the propeller clamp 1 includes a propeller clamp cover 11, a propeller clamp base 12, and a blade connector 13. The propeller body 2 is clamped between the propeller clamp cover 11 and the propeller clamp base 12. The blade connector 13 connects the propeller clamp base 12, the propeller body 2, and the propeller clamp cover 11 into one piece. Specifically, a cover screw hole 112 is provided on the propeller clamp cover 11, a connecting through hole 22 is provided on the propeller body 2, and a base shaft hole 121 is provided on the propeller clamp base 12. The propeller connector 13 is inserted from the bottom of the propeller clamp base 12, passes through the base shaft hole 121 and the connecting through hole 22, and is connected to the blade fastener 14. Since the blade connector 13 and the blade fastener 14 press the propeller clamp base 12 and the propeller clamp cover 11 respectively, the propeller clamp base 12, the propeller body 2, and the propeller clamp cover 11 are connected into one piece.

[0031] Specifically, continue to refer to Figure 2 As shown, the oar clamp upper cover 11 and the oar clamp base 12 are directly locked and connected via an oar clamp fastener 15 to maintain the stability of the oar clamp 1.

[0032] Specifically, continue to refer to Figure 2 As shown, the connecting pin 4 includes a short pin 41, a long pin 42, and a pin fastener 43. The short pin 41 is inserted into the pin hole 31, and the long pin 42 passes through the pin housing 111 and plugs into the short pin 41. The pin fastener 43 connects the long pin 42 and the short pin 41. This facilitates assembly between the connecting pin 4 and the oar clamp 1. Specifically, the pin housing 111 is disposed within the oar clamp upper cover 11. A bearing 44 is installed within the pin housing 111, and the long pin 42 is installed within the bearing 44, facilitating the deflection of the oar clamp 1.

[0033] Specifically, wear-resistant washers 23 are provided between the blade clamp upper cover 11 and the blade body 2 and between the blade clamp base 12 and the blade body 2, respectively, to reduce root wear.

[0034] Specifically, refer to Figure 4 As shown, it also includes a buffer assembly 5, which is installed on the fixing seat 3, and buffer parts are respectively provided at both ends of the buffer assembly 5; the propeller clamp 1 is provided with two abutting ends corresponding to the two blade bodies 2 respectively; the two abutting ends are respectively located on both sides of the buffer assembly 5; when the blade body 2 on one side is deflected downward, the corresponding abutting end abuts against and squeezes the buffer part.

[0035] When the blade body 2 on one side deflects downward, the buffer member abuts against the corresponding abutting end of the blade body 2 on that side, providing a reverse force, which can reduce the degree of downward deflection of the blade body 2, thereby further automatically correcting the blade; and during the swinging of the blade body 2, the buffer member can play a buffering role, reducing the vibration of the fixing seat 3 caused by the swinging of the blade body 2, and further improving the stability during flight.

[0036] It should be noted that the buffer assembly 5 can have various structural forms, which are described by way of example in this embodiment. Figure 4 As shown, the buffer assembly 5 includes an outer shell 51, a push pin 52 and an elastic member 53. A push pin guide hole 511 extending along a first direction is provided in the outer shell 51, and the first direction is the extension direction of the blade body 2. Push pins 52 movable along the first direction are respectively provided at both ends of the push pin guide hole 511, that is, the outer contour of the push pin 52 is adapted to the push pin guide hole 511, so that the push pin 52 can slide in the push pin guide hole 511. The push pin 52 extends outward from the push pin guide hole 511, and the push pin 52 is used to abut against the abutting end; the elastic member 53 is arranged between the two push pins 52, and has elastic potential energy that drives the two push pins 52 to move away from each other, that is, it has elastic potential energy that drives the push pin 52 to extend outward from the push pin guide hole 511. When the blade body 2 on one side deflects downward, the corresponding blade clamp 1 abuts against the ejector pin 52 , and the elastic member 53 can limit and buffer the deflection of the blade body 2 , thereby achieving the effect of automatic correction and shock absorption.

[0037] Specifically, refer to Figure 5 As shown, the ejector pin 52 is provided with a movable groove 521. A ejector pin stopper 54 is connected to the outer housing 51 and inserted into the movable groove 521. The length of the movable groove 521 is greater than the diameter of the ejector pin stopper 54, and the ejector pin stopper 54 is used to limit the travel of the ejector pin 52. The ejector pin stopper 54 cooperates with the movable groove 521 to limit the maximum and minimum extension length of the ejector pin 52. The end of the ejector pin 52 that extends out of the ejector pin guide hole 511 is provided with a spherical surface to facilitate relative movement between the ejector pin 52 and the abutting end.

[0038] Specifically, the paddle clip 1 includes a paddle clip body and a rubber cushion 16. The paddle clip body has a groove at its bottom, and the rubber cushion 16 is connected to the paddle clip body and abuts against the sidewall of the groove. The side of the rubber cushion 16 facing the ejector pin 52 serves as the abutment end. The provision of the rubber cushion 16 further provides cushioning and improves the shock absorption effect.

[0039] Specifically, the outer shell 51 is located below the oar clamp base 12 , and the rubber buffer pad 16 is installed in the oar clamp base 12 .

[0040] Specifically, refer to Figure 6 As shown, the top of the rubber buffer 16 is provided with a rubber pad fixing portion 161, which is equipped with a stopper 162. The paddle clamp body is provided with a rubber pad fixing hole. After the rubber pad fixing portion 161 passes through the rubber pad fixing hole, the stopper 162 abuts against the paddle clamp body. A shaped block 163 is provided on the side of the rubber buffer 16 away from the abutting end. The sidewall of the groove is provided with a shaped groove, and the shaped block 163 snaps into the shaped groove. By squeezing the rubber pad fixing portion 161 and the shaped block 163, they deform, making it easier to install the rubber buffer 16 in the paddle clamp 1.

[0041] The principle of automatic balance correction: Reference Figure 7-10 As shown, the blade body 2 is in a balanced state with no deflection. The torsion angle of the blade bodies 2 on both sides is 9°. At this point, the ejector pins 52 at both ends of the outer shell 51 extend outward under the action of the elastic members 53 and are restrained by the ejector pin stoppers 54 to their maximum extension length.

[0042] Reference Figure 11-14 As shown, when the blade body 2 on one side is deflected downward by the airflow, the blade body 2 on the other side will also deflect upward. Since the axis of the blade body 2 deflection intersects with the axis of symmetry of the blade body 2, that is, the axis of the connecting pin 4 intersects with the first axis 21, the torsion angle of the blade body 2 that is deflected downward increases to 10°, and the torsion angle of the blade body 2 on the other side decreases, which increases the windward force area of ​​the blade body 2 that is deflected downward, and the lift force it receives is greater, driving the blade body 2 to rotate in the opposite direction of the deflection, thereby forming an automatic correction and driving the blade body 2 to return to a balanced state. In addition, when the blade body 2 deflects downward, the corresponding rubber buffer pad 16 is abutted against the top pin 52, and under the action of the elastic member 53, it plays a role in preventing the blade body 2 from deflecting downward, thereby further achieving the deflection correction of the blade body 2, and also plays a shock-absorbing effect.

[0043] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0044] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A paddle clamp device, characterized in that: include: Oar clamp, equipped with a pin shaft warehouse; The two blade bodies are respectively connected to the blade clamps so that the two blade bodies are symmetrically arranged along the first axis; the blade bodies form a torsion angle from the tip to the root; The fixing seat is provided with a pin hole; The connecting pin passes through the pin shaft bin and the pin shaft hole, so that the propeller clamp is rotatably connected to the fixing seat; the axis of the connecting pin shaft is arranged crosswise with the first axis, so that the torsion angle increases when the propeller body deflects downward.

2. A paddle clamp device according to claim 1, characterized in that: The axis of the connecting pin is arranged to cross the first axis to form an angle of 5° to 10°.

3. The paddle clamp device according to claim 1, characterized in that: The paddle clamp comprises an upper paddle clamp cover, a paddle clamp base and a paddle blade connector; the paddle blade body is clamped between the upper paddle clamp cover and the paddle clamp base; the paddle blade connector connects the paddle clamp base, the paddle blade body and the upper paddle clamp cover into one body.

4. The paddle clamp device according to claim 1, characterized in that: The connecting pin shaft comprises a short pin shaft, a long pin shaft and a pin shaft fastener; the short pin shaft is inserted into the pin shaft hole, and the long pin shaft passes through the pin shaft bin and is plugged into the short pin shaft; The pin fastener connects the long pin and the short pin.

5. The paddle clamp device according to claim 1, characterized in that: It also includes a buffer assembly, which is installed on a fixed seat, and buffer parts are respectively provided at both ends of the buffer assembly; the paddle clamp is provided with two abutting ends corresponding to the two blade bodies respectively; the two abutting ends are respectively located on both sides of the buffer assembly; in the process of causing the blade body on one side to deflect downward, the corresponding abutting end abuts against and squeezes the buffer part.

6. The paddle clamp device according to claim 5, characterized in that: The buffer assembly includes an outer shell, a push pin and an elastic member; a push pin guide hole extending along a first direction is provided in the outer shell; push pins movable along the first direction are respectively provided at both ends of the push pin guide hole, the push pins extending out of the push pin guide hole, and the push pins are used to abut against the abutting end; the elastic member is arranged between the two push pins and has elastic potential energy for driving the two push pins away from each other.

7. The paddle clamp device according to claim 6, characterized in that: A movable groove is provided in the ejector pin, and the ejector pin limiting piece is connected to the outer shell and inserted into the movable groove. The length of the movable groove is greater than the diameter of the ejector pin limiting piece, and the ejector pin limiting piece is used to limit the moving stroke of the ejector pin.

8. The paddle clamp device according to claim 6, characterized in that: The oar clamp includes an oar clamp body and a rubber buffer pad; a groove is provided at the bottom of the oar clamp body, the rubber buffer pad is connected to the oar clamp body and abuts against the side wall of the groove; the side of the rubber buffer pad facing the ejector pin is the abutment end.

9. The paddle clamp device according to claim 8, characterized in that: A rubber pad fixing portion is provided on the top of the rubber buffer pad, and a limit block is provided on the rubber pad fixing portion; a rubber pad fixing hole is provided on the paddle clamp body; after the rubber pad fixing portion passes through the fixing hole, the limit block is abutted against the paddle clamp body.

10. The paddle clamp device according to claim 9, characterized in that: A special-shaped block is provided on one side of the rubber buffer pad away from the abutting end, and a special-shaped groove is provided on the side wall of the groove, and the special-shaped block is stuck in the special-shaped groove.

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