High-strength bottom fork structure for motorcycle

Abstract

The high-strength bottom fork structure comprises two bottom fork arms and a cross beam integrally formed with the two bottom fork arms, connectors extending downwards are arranged on the two sides of the bottom of the cross beam respectively, connecting sleeves are arranged on the opposite sides of the two connectors respectively, and a gap allowing the connecting end of a buffer frame to be inserted in is formed between the two connecting sleeves. The two connecting sleeves are each sleeved with a fixing sleeve and a reset spring, one end of each reset spring abuts against the inner wall of the corresponding connector, the other end of each reset spring abuts against the inner end of the corresponding fixing sleeve, and the two sides of the end, connected with the connectors, of the buffer frame are provided with casing pipes which communicate with each other and are inserted into the two fixing sleeves respectively. The rotating shaft can rotate relative to the connecting sleeve and the sleeve. Compared with the prior art, the utility model has the advantages that the fixing sleeve and the connecting sleeve increase the supporting area with the buffer rack, disperse the acting force of the buffer rack on the bottom fork, enhance the strength of the joint of the buffer rack and the connector, and prolong the service life of the bottom fork.

Description

TECHNICAL FIELD

[0001] The utility model relates to motorcycle technical field especially relates to high strength flat fork structure for motorcycle. BACKGROUND

[0002] The flat fork structure of the motorcycle is the key component connecting the frame and the rear wheel, and its strength and stability directly affect the riding safety, comfort and service life. In order to improve the strength and stability of the motorcycle, various structures of the motorcycle for improving the strength and stability of the motorcycle appear on the market.

[0003] For example, the Chinese utility model patent with the patent announcement number CN217835923U "rear shock connection structure of motorcycle" includes a main frame and a rear flat fork, the rear flat fork is rotatably connected to the rear end of the main frame, the bottom of the rear flat fork is provided with a buffer bracket connected with the rear shock absorber, a cross bar is arranged on the rear flat fork, a first connecting bracket is arranged on the cross bar, the first connecting bracket is arranged at the bottom of the rear flat fork, and the first connecting end of the buffer bracket is rotatably connected to the first connecting bracket.

[0004] In the above scheme, the shock absorber is connected with the first connecting bracket through the buffer bracket, and only the bearing at the connecting position of the first connecting bracket and the buffer bracket bears the impact force of the buffer bracket and the shock absorber, so the strength is not high, and the first connecting bracket is prone to deformation and fracture. UTILITY MODEL CONTENTS

[0005] The utility model discloses a high-strength flat fork structure for motorcycle to solve the above problems.

[0006] The utility model discloses a high-strength flat fork structure for motorcycle to solve the above problems.

[0007] The outer diameter of the sleeve pipe is equal to the outer diameter of the connecting sleeve, and the outer diameter of the sleeve pipe is equal to the inner diameter of the fixing sleeve.

[0008] The further preferred scheme of the utility model is that when the reset spring is compressed to the maximum stroke, the fixed sleeve is completely sleeved on the connecting sleeve, when the reset spring rebounds to the natural state, one side of the fixed sleeve is sleeved on the connecting sleeve, and the other side is sleeved on the sleeve pipe.

[0009] The further preferred scheme of the utility model is that the interval between the two connecting sleeves is equal to the interval between the outer ends of the two sleeve pipes.

[0010] The further preferred scheme of the utility model is that the interval between the two flat fork arms gradually decreases from the front end to the cross beam, and gradually increases from the cross beam to the rear end.

[0011] The further preferred scheme of the utility model is that the thickness of the two flat fork arms gradually increases from the two ends to the intersection with the cross beam, and the connecting head is located at the intersection of the cross beam and the two flat fork arms.

[0012] The further preferred scheme of the utility model is that the top surface of the cross beam is upwardly convex, and the intersection of the upper surface of the cross beam and the two flat fork arms is a curved surface with smooth transition.

[0013] The further preferred scheme of the utility model is that the front side wall of the cross beam is an arc surface recessed towards the front wheel direction, and the rear side wall of the cross beam is an arc surface recessed towards the rear wheel direction.

[0014] The further preferred scheme of the utility model is that the flat fork arm on one side of the proximity chain is fixed with a protective sleeve covering the upper surface and the lower surface in contact with the chain, and the protective sleeve is used for preventing the chain from causing abrasion to the flat fork arm.

[0015] The further preferred scheme of the utility model is that a limiting strip for preventing the chain from shaking is fixed on the protective sleeve, the chain is located inside the limiting strip, and the protective sleeve is a rubber sleeve.

[0016] Compared with the prior art, the utility model has the advantages that the connecting sleeve is arranged on the opposite side of the two connecting heads, the fixed sleeve and the reset spring are arranged on the connecting sleeve, the sleeve pipe on the two sides of the buffer frame is inserted into the two fixed sleeves, the connecting sleeve and the sleeve pipe are rotatable relative to the rotating shaft, when the motorcycle runs on the road and encounters a rugged section, the two flat fork arms swing, the buffer frame swings to make the damping device work, the buffer frame is supported by the rotating shaft and the fixed sleeve and the connecting sleeve on the two sides in the swinging process, compared with the buffer frame relying on the rotating shaft for support only, the fixed sleeve and the connecting sleeve increase the support area of the buffer frame, disperse the force of the buffer frame on the flat fork, enhance the strength of the connection between the buffer frame and the connecting head, avoid the breakage of the connecting head caused by the concentrated force of the buffer frame, and prolong the service life of the flat fork. BRIEF DESCRIPTION OF DRAWINGS

[0017] The utility model will be further described in detail below in combination with the drawings and preferred embodiments, but those skilled in the art will appreciate that these drawings are only drawn for the purpose of explaining the preferred embodiments and therefore should not be regarded as limiting the scope of the utility model, in addition, unless specifically indicated, the drawings only schematically show the composition or structure of the described object conceptually and can contain exaggerated display, and the drawings are not necessarily drawn to scale.

[0018] Figure 1 It is one of the preferred embodiment of the utility model three-dimensional structure schematic diagram;

[0019] Figure 2 It is the second preferred embodiment of the utility model three-dimensional structure schematic diagram;

[0020] Figure 3 It is the preferred embodiment of the utility model plan view;

[0021] Figure 4 It is the preferred embodiment of the utility model Figure 3 The sectional view at A-A in the preferred embodiment of the utility model;

[0022] Figure 5 It is the preferred embodiment of the utility model Figure 4 The local enlarged view at B in the preferred embodiment of the utility model;

[0023] Figure 6 It is the preferred embodiment of the utility model explosion view.

[0024] In the drawing: 1, flat fork arm;2, crossbeam;3, connecting head;4, connecting sleeve;5, fixed sleeve;6, reset spring;7, buffer frame;71, sleeve;8, rotating shaft;9, protective sleeve;10, limiting strip. DETAILED DESCRIPTION

[0025] The preferred embodiments of the utility model will be described in detail below with reference to the drawings, and those skilled in the art will appreciate that these descriptions are only descriptive, exemplary and should not be interpreted as limiting the protection scope of the utility model.

[0026] It should be noted that: similar signs represent similar items in the following drawings, therefore, once an item is defined in one drawing, it can not be further defined and explained in the subsequent drawings.

[0027] This embodiment mainly describes the high-strength flat fork structure for motorcycle, as follows:

[0028] As Figures 1 to 6As shown, the high-strength flat fork structure for a motorcycle includes two flat fork arms 1 and a cross beam 2, which is integrally formed between the two flat fork arms 1 and is integrally arranged with the flat fork structure, thereby improving the overall structural strength of the flat fork and reducing stress concentration caused by welding or splicing. The bottom of the cross beam 2 has a connecting head 3 extending downward on each side, which is used to connect with the buffer bracket 7 on the damping device. The opposite sides of the two connecting heads 3 each have a connecting sleeve 4, and the two connecting sleeves 4 have a spacing for the connecting end of the buffer bracket 7 to be inserted. The two connecting sleeves 4 each have a fixing sleeve 5 and a return spring 6 fitted thereon, with one end of the return spring 6 abutting against the inner wall of the connecting head 3 and the other end abutting against the inner end of the fixing sleeve 5. The buffer bracket 7 has a sleeve 71 on each side of the connecting end, which is in communication with each other and is inserted into the two fixing sleeves 5, respectively. When the buffer bracket 7 is installed, the fixing sleeve 5 is fitted on one side of the connecting sleeve 4, the connecting end of the buffer bracket 7 is inserted between the two connecting sleeves 4, one side of the sleeve 71 is inserted into the fixing sleeve 5 on the connecting sleeve 4, and the fixing sleeve 5 is pressed to deform the return spring 6. Then, the other fixing sleeve 5 is fitted on the other side of the connecting sleeve 4, and the other sleeve 71 on the buffer bracket 7 is aligned with the fixing sleeve 5. At this time, the other sleeve 71 is inserted into the same side of the fixing sleeve 5 under the action of the return spring 6. Then, the buffer bracket 7 is connected between the two connecting heads 3 by a rotating shaft 8 penetrating through the two connecting heads 3, the connecting sleeves 4 and the sleeves 71. The rotating shaft 8 is rotatable relative to the connecting sleeves 4 and the sleeves 71. When the motorcycle encounters rough road sections during driving on the road, the two flat fork arms 1 swing, and the buffer bracket 7 swings to work the damping device. The buffer bracket 7 is supported by the rotating shaft 8 and the fixing sleeves 5 and the connecting sleeves 4 on both sides during the swinging process. Compared with the buffer bracket 7 relying only on the rotating shaft 8 for support, the fixing sleeves 5 and the connecting sleeves 4 in this scheme increase the support area of the buffer bracket 7, disperse the force of the buffer bracket 7 on the flat fork, enhance the strength of the connection between the buffer bracket 7 and the connecting head 3, avoid the force concentration of the buffer bracket 7 causing the connecting head 3 to break, and prolong the service life of the flat fork.

[0029] Specifically, to ensure the close fit between the sleeve 71 and the fixing sleeve 5 and the connecting sleeve 4, prevent looseness or abnormal noise caused by size deviation, and ensure the stable compression and rebound stroke of the return spring 6, the outer diameter of the sleeve 71 is equal to the outer diameter of the connecting sleeve 4, and the outer diameter of the sleeve 71 is equal to the inner diameter of the fixing sleeve 5.

[0030] Specifically, to facilitate the installation of the buffer bracket 7 and avoid the excessive length of the fixing sleeve 5 causing the buffer bracket 7 to be unable to be installed, the buffer bracket 7 needs to be limited. When the return spring 6 is compressed to the maximum stroke, the fixing sleeve 5 is completely fitted on the connecting sleeve 4. When the return spring 6 rebounds to the natural state, one side of the fixing sleeve 5 is fitted on the connecting sleeve 4, and the other side is fitted on the sleeve 71.

[0031] Specifically, to ensure the accurate insertion of the sleeve 71 into the gap between the connecting sleeves 4, avoid assembly difficulties caused by too small gap, and avoid the excessive gap causing the buffer bracket 7 to slide left and right along the rotating shaft 8 during rotation, causing excessive wear of the buffer bracket 7 and the rotating shaft 8 and the fixed sleeve 5, the gap between the two connecting sleeves 4 is designed to be equal to the gap between the outer ends of the two sleeve 71. When the buffer bracket 7 is installed on the rotating shaft 8, the outer end of the sleeve 71 abuts against the outer end of the connecting sleeve 4.

[0032] Specifically, the gap between the two fork arms 1 gradually decreases from the front end to the crossbeam 2, and gradually increases from the crossbeam 2 to the rear end. The reduction of the front end gap can reduce material redundancy and reduce the overall weight of the fork, and at the same time, by concentrating the support force at the crossbeam 2, a "mechanical node" is formed to enhance the bending and torsional resistance. The crossbeam 2 as a key connection point, the compact design of its position can effectively disperse the longitudinal and vertical load from the frame, and the increase of the rear end gap can expand the support area and installation space of the rear wheel mounting area, avoiding motion interference.

[0033] Specifically, the thickness of the two fork arms 1 gradually increases from both ends to the intersection with the crossbeam 2, and the connecting head 3 is located at the intersection of the crossbeam 2 and the two fork arms 1. The gradual thickness change design can effectively absorb the impact when the motorcycle jumps and lands; increasing the thickness at the crossbeam 2 connection can improve the bending resistance of the fork, and using the high-strength area at the intersection to fix the connecting head 3 can avoid excessive local stress leading to fracture.

[0034] Specifically, to improve the compression resistance of the crossbeam 2 and adapt to complex stress conditions, the top surface of the crossbeam 2 is designed to be convex upward, and the intersection of the upper surface of the crossbeam 2 and the two fork arms 1 is a smooth transition curved surface. The curved surface transition design can reduce stress concentration and avoid fatigue cracks at the right-angle connection. The front side wall of the crossbeam 2 is an arc surface concave to the front wheel direction, and the rear side wall of the crossbeam 2 is an arc surface concave to the rear wheel direction. The design of the front side wall arc surface can reduce wind resistance, and the design of the rear side wall arc surface can enhance the dispersion ability of the impact force on the rear wheel and improve the structural stability.

[0035] As shown in Figure 1 , Figure 2 , Figure 3 and Figure 5 , to prevent the chain from directly contacting the fork arm 1 during chain transmission, causing the fork arm 1 to wear and shorten the service life of the fork arm 1, a protective sleeve 9 is fixed on the fork arm 1 near the chain side to cover the upper surface and the lower surface in contact with the chain, and a limiting strip 10 is fixed on the protective sleeve 9. The limiting strip 10 is used to prevent the chain from shaking, coming off or hitting the fork arm 1, and the chain is located inside the limiting strip 10. The protective sleeve 9 is a rubber sleeve. The rubber material of the protective sleeve 9 can absorb the vibration noise of the chain and improve the riding comfort.

[0036] In the description of the utility model, it needs to explain, the term "upper", "lower", "front", "back", "internal", "external" and so on indicate the orientation or position relation is based on the orientation or position relation shown in the drawing, or is the orientation or position relation of the utility model product when using the usual placement, just is for the convenience of describing the utility model and simplifying the description, and is not indicate or imply the device or element must have the specific orientation, with the specific orientation structure and operation, therefore can not be understood as the limitation to the utility model.

[0037] The high-strength flat fork structure for motorcycle provided by the utility model is described in detail above, the principle and implementation mode of the utility model are described by applying specific examples in this paper, the above embodiment is only used for helping to understand the utility model and core idea, it should be pointed out that, for ordinary skilled person in the art, on the premise of not departing from the principle of the utility model, the utility model can be improved and modified in several ways, and these improvements and modifications also fall within the protection scope of the utility model claims.

Claims

1. A high-strength fork structure for a motorcycle, comprising two fork arms and a cross member integrally formed with the two fork arms between the two fork arms, characterized in that: The bottom of the crossbeam has two downwardly extending connecting heads on both sides, which are used to connect with the buffer frame on the damping device, and the opposite sides of the two connecting heads have connecting sleeves with a spacing for the insertion of the connecting end of the buffer frame, and the two connecting sleeves are sleeved with fixing sleeves and return springs, one end of the return spring abuts against the inner wall of the connecting head and the other end abuts against the inner end of the fixing sleeve, the buffer frame has two sleeves on one end connected with the connecting head, which are in communication with each other and are inserted into the two fixing sleeves respectively, the crossbeam is provided with a rotating shaft penetrating through the two connecting heads, connecting sleeves and sleeves, and the rotating shaft can rotate relative to the connecting sleeves and sleeves.

2. The high-strength platform fork structure for a motorcycle according to claim 1, characterized by: The outer diameter of the sleeve is equal to the outer diameter of the connecting sleeve, and the outer diameter of the sleeve is equal to the inner diameter of the fixing sleeve.

3. The high-strength platform fork structure for a motorcycle according to claim 1, characterized by: When the return spring is compressed to the maximum stroke, the fixing sleeve is completely sleeved on the connecting sleeve, and when the return spring rebounds to the natural state, the fixing sleeve is sleeved on the connecting sleeve on one side and on the sleeve on the other side.

4. The high-strength platform fork structure for a motorcycle according to claim 1, characterized by: The spacing between the two connecting sleeves is equal to the spacing between the outer ends of the two sleeves.

5. The high-strength platform fork structure for a motorcycle according to claim 1, characterized by: The spacing between the two fork arms gradually decreases from the front end to the crossbeam and gradually increases from the crossbeam to the rear end.

6. The high-strength platform fork structure for a motorcycle according to claim 1, characterized by: The thickness of the two fork arms gradually increases from the two ends to the intersection with the crossbeam, and the connecting head is located at the intersection of the crossbeam and the two fork arms.

7. The high-strength platform fork structure for a motorcycle according to claim 1, characterized by: The top surface of the crossbeam is upwardly convex, and the intersection of the upper surface of the crossbeam and the two fork arms is a smooth transition curved surface.

8. The high-strength platform fork structure for a motorcycle according to claim 1, characterized by: The front side wall of the crossbeam is an arc surface concave to the front wheel direction, and the rear side wall of the crossbeam is an arc surface concave to the rear wheel direction.

9. The high-strength platform fork structure for a motorcycle according to claim 1, characterized by: The fork arm near the side of the chain is fixed with a protective sleeve covering the upper surface and the lower surface in contact with the chain, which prevents the chain from wearing the fork arm.

10. The high-strength platform fork structure for a motorcycle according to claim 9, characterized by: The protective sleeve is fixed with a limiting strip to prevent the chain from shaking, the chain is located inside the limiting strip, and the protective sleeve is a rubber sleeve.

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