Bicycle fluted disc upshift structure

Abstract

A bicycle fluted disc upshift structure comprises a fluted disc body provided with a plurality of meshing teeth surrounding the peripheral surface of the fluted disc body; the upshift promoting part is arranged on the fluted disc body, is adjacent to the peripheral surface of the fluted disc and is used for promoting a chain to move from the fluted disc body to an adjacent smaller fluted disc body; the upshift promoting part comprises an upshift promoting tooth and an upshift promoting groove; the top end of the upshift promoting tooth is provided with an upshift tooth top surface; the upshift promoting groove is communicated with the upshift promoting tooth; the lifting resisting tooth is arranged on the peripheral surface of the fluted disc body, is adjacent to the upshift promoting tooth and is used for preventing the chain from moving from the fluted disc body to the adjacent smaller fluted disc body; the top end of the lifting resisting tooth is provided with a lifting resisting tooth top surface; the height of the top surface of the lifting resisting tooth is smaller than that of the top surface of the upshift tooth; the thickness of the top surface of the lifting resisting tooth is smaller than that of the top surface of the upshift tooth; and the width of the top surface of the lifting resisting tooth is smaller than that of the top surface of the upshift tooth. Therefore, the upshift benefit is maximized.

Description

Technical Field

[0001] The utility model relates to a bicycle toothed disc, in particular to a bicycle toothed disc upshift structure which can limit the upshift position of a chain. Background Art

[0002] Currently, bicycles can be changed by using different sized toothed discs when riding. Basically, the front and rear derailleurs are combined with different sized toothed discs to change the transmission ratio of the chain between the toothed discs. This design allows riders to adjust the speed of the pedals under different conditions to cope with different speeds and terrains.

[0003] Generally speaking, one of the most common ways to change gears is through a rear derailleur and cassette. The rear wheel of a bicycle is usually equipped with multiple chainrings, each with a different number of teeth, and a rear derailleur located on the rear wheel frame. The function of the rear derailleur is to change the size of the rear chainring that the chain is connected to. With the front chainring unchanged, a larger rear chainring provides a lower gear ratio, making it easier for the rider to go uphill. A smaller rear chainring provides a higher gear ratio, which is suitable for fast and flat roads.

[0004] However, when the chain moves on the rear sprocket, problems often occur. For example, when the chain shifts from a larger sprocket to a smaller sprocket, it is easy for the chain to take some time to switch from one sprocket to another during the speed change process due to the relationship between the sprocket structure. A known sprocket structure discloses that at least one upshift promotion area and at least one upshift promotion tooth are provided on the sprocket, so that the chain can move along the upshift promotion area to the adjacent sprocket through the upshift promotion tooth; however, there is no corresponding restriction structure before and after the upshift promotion tooth, so that the chain may still not be upshifted from the upshift promotion tooth, and the maximum upshift efficiency cannot be achieved. Therefore, how to ensure that the chain can be upshifted on the upshift promotion tooth is a problem that needs to be solved urgently by technicians and researchers in related fields. Utility Model Content

[0005] The main purpose of the utility model is to provide a bicycle gear disc upshifting structure, which can limit the chain to upshift in the upshifting promotion area, so as to maximize the upshifting benefit.

[0006] To achieve the above-mentioned purpose of the utility model, the utility model discloses a bicycle sprocket shifting structure, comprising: a sprocket body, having a plurality of meshing teeth surrounding the outer peripheral surface of the sprocket body; a shifting promotion portion, arranged on the sprocket body and adjacent to the outer peripheral surface of the sprocket, for promoting a chain to move from the sprocket body to an adjacent smaller sprocket body; the shifting promotion portion comprises a shifting promotion tooth and a shifting promotion groove; the top of the shifting promotion tooth has a shifting tooth top surface; the shifting tooth top surface has a first height relative to the bottom of the shifting promotion tooth, the shifting tooth top surface has a first thickness along the circumferential direction of the sprocket body, and the shifting tooth top surface has a first width along the axial direction of the sprocket body; the shifting promotion groove is connected to the sprocket body. connected to the upshift promoting tooth; and an anti-upshift tooth, which is arranged on the outer circumferential surface of the sprocket body and adjacent to the upshift promoting tooth, for preventing the chain from moving from the sprocket body to the adjacent smaller sprocket body; the top end of the anti-upshift tooth has a top surface of the anti-upshift tooth; the top surface of the anti-upshift tooth has a second height relative to the bottom of the anti-upshift tooth, the top surface of the anti-upshift tooth has a second thickness along the circumferential direction of the sprocket body, and the top surface of the anti-upshift tooth has a second width along the axial direction of the sprocket body; wherein the second height of the top surface of the anti-upshift tooth is less than the first height of the top surface of the upshift tooth; the second thickness of the top surface of the anti-upshift tooth is less than the first thickness of the top surface of the upshift tooth; the second width of the top surface of the anti-upshift tooth is less than the first width of the top surface of the upshift tooth.

[0007] In one embodiment, the toothed disc body has a first side surface and a second side surface respectively on two opposite sides along the axial direction; the distance between the top surface of the resistance tooth and the first side surface is smaller than the distance between the top surface of the resistance tooth and the second side surface.

[0008] In one embodiment, the distance between the upshift tooth top surface and the first side surface is greater than the distance between the upshift tooth top surface and the second side surface.

[0009] In one embodiment, the lift-blocking tooth has a first section and a second section; the first section is connected to the first side surface of the toothed disc body; the second section is connected to the second side surface of the toothed disc body; the first section has a first slope relative to the axial direction of the toothed disc body, the second section has a second slope relative to the axial direction of the toothed disc body, and the first slope is greater than the second slope.

[0010] In one embodiment, the lift-blocking tooth has a driving surface and a driven surface respectively on two opposite sides along the circumferential direction of the gear plate body; the driving surface and the driven surface are respectively connected to the opposite ends of the top surface of the lift-blocking tooth, and the driven surface is closer to the upshifting promoting tooth than the driving surface; wherein the driving surface has a first curvature, the driven surface has a second curvature, and the first curvature is greater than the second curvature.

[0011] In one embodiment, one end of the upshift promotion groove extends to below the upshift resistance tooth, and the upshift resistance tooth is not connected to the upshift promotion groove.

[0012] In one embodiment, the gear disc body defines a root circle, which is a virtual circle passing through the roots of the multiple meshing teeth; the first height is the distance between the top surface of the upshift tooth and the root circle; the second height is the distance between the top surface of the resistance tooth and the root circle.

[0013] In one embodiment, the top surface of the upshift-blocking tooth is offset in a direction away from the upshift-promoting tooth.

[0014] According to the purpose and effect of the present invention, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a front view of a preferred embodiment of the utility model.

[0016] Figure 2 It is a partially enlarged front view of a preferred embodiment of the utility model.

[0017] Figure 3 It is a partially enlarged stereoscopic view of a preferred embodiment of the utility model.

[0018] Figure 4 It is a partially enlarged top view of a preferred embodiment of the utility model.

[0019] Figure 5 It is a cross-sectional view of the upshift promoting tooth of a preferred embodiment of the utility model.

[0020] Figure 6 It is a cross-sectional view of a lift-resistance tooth according to a preferred embodiment of the utility model. DETAILED DESCRIPTION

[0021] The following description with reference to the accompanying drawings is a preferred embodiment of the present invention. It should be understood that the drawings and descriptions are for illustrative purposes only and are not intended to limit the present invention. In addition, the terms "upper" and "lower", "left" and "right", "front" and "rear", "first" and "second" ... described in the specification are used to clearly illustrate the relative positions between components or mechanisms, and are not intended to be limiting terms.

[0022] See also Figure 1 and Figure 2 As shown, a preferred embodiment of the present invention provides a bicycle gear shifting structure which mainly includes a gear body 10 , at least one gear shifting promotion portion 20 and at least one gear shifting resistance 30 .

[0023] in:

[0024] The sprocket body 10 has an annular base 11 and a plurality of meshing teeth 12. The plurality of meshing teeth 12 extend radially outward from the base 11 and are arranged in a ring on the outer peripheral surface of the sprocket body 10 for meshing with the chain (not shown). The sprocket body is defined with a root circle R1 and a tip circle R2. The root circle R1 is defined as a virtual circle passing through the root of each meshing tooth 12. The tip circle R2 is defined as a virtual circle passing through the tip of each meshing tooth 12. The sprocket body 10 has a first side surface 13 and a second side surface 14 on two opposite sides along the axial direction. When the sprocket body 10 is installed in a sprocket assembly, the first side surface 13 faces an adjacent smaller sprocket (not shown), and the second side surface 14 faces away from the adjacent smaller sprocket.

[0025] The upshift promoting portion 20 is disposed at the edge of the sprocket body 10 to promote an upshifting action of the chain moving from the sprocket body 10 to the adjacent smaller sprocket. In this embodiment, the sprocket body 10 has three upshift promoting portions 20. The upshift promoting portion 20 includes at least one upshift promoting tooth 21 and an upshift promoting groove 22. The upshift promoting tooth 21 is disposed on the outer peripheral surface of the sprocket body 10, replacing one of the meshing teeth 12. The top of the upshift promotion tooth 21 has an upshift tooth top surface 210, which is located on the tooth top circle R2, and has a first height H1 with the tooth root of the upshift promotion tooth 21, which represents the vertical distance from the upshift tooth top surface 210 to the tooth root circle R1; the upshift tooth top surface 210 has a first thickness D1 along the circumferential direction of the gear plate body 10, which represents the length of the upshift tooth top surface 210 extending in the arc direction along the tooth top circle R2; the upshift tooth top surface 210 has a first width W1 along the axial direction of the gear plate body 10, which represents the length of the upshift tooth top surface 210 extending in the axial direction of the gear plate body 10. The distance between the upshift tooth top surface 210 of the upshift promotion tooth 21 and the first side surface 13 is greater than the distance between the upshift tooth top surface 210 and the second side surface 14, so that the upshift tooth top surface 210 of the upshift promotion tooth 21 is offset toward the second side surface 14. Thereby, the chain can more easily complete the upshifting action from the upshifting promoting tooth 21. The upshifting promoting groove 22 is provided on the sprocket body 10 and is adjacent to the outer peripheral surface of the sprocket body 10, and is connected to the upshifting promoting tooth 21. Specifically, the upshifting promoting groove 22 is formed on the first side surface 13 of the sprocket body 10, and is recessed in the direction toward the second side surface 14. It is used to reduce the interference between the sprocket body 10 and the chain during the upshifting of the chain from the sprocket body 10 to the adjacent smaller sprocket body. The upshifting promoting groove 22 has a side concave surface 220 and a bottom concave surface 221, the side concave surface 220 is connected to the bottom concave surface 221, and the bottom concave surface 221 is farther away from the upshifting tooth top surface 210 than the side concave surface 220. The side concave surface 220 is generally parallel to the first side surface 13, and the bottom concave surface 221 is inclined relative to the first side surface 13. The chain can be guided from the upshift promotion tooth 21 to the adjacent smaller toothed disc body by the side concave surface 220 and the bottom concave surface 221 of the upshift promotion recess 22. One end of the upshift promotion recess 22 extends below the resistance tooth 30 and is not connected to the resistance tooth 30.

[0026] The anti-lift tooth 30 is disposed on the outer peripheral surface of the sprocket body 10, adjacent to the upshift promoting tooth 21 of the upshift promoting portion 20, and there is no other tooth between the anti-lift tooth 30 and the upshift promoting tooth 21. In the present embodiment, the number of the anti-lift teeth 30 is three, corresponding to the three upshift promoting portions 20. The anti-lift tooth 30 is used to limit the chain to perform upshifting only in the upshift promoting portion 20. Specifically, the anti-lift tooth 30 has an anti-lift tooth top surface 31, a driving surface 32, a driven surface 33, a first cut surface 34 and a second cut surface 35. The anti-lift tooth top surface 31 is located at the top of the anti-lift tooth 30, adjacent to the tooth top circle R2, and the anti-lift tooth top surface 31 has a second height H2 relative to the tooth root of the anti-lift tooth 30, representing the vertical distance from the anti-lift tooth top surface 31 to the tooth root circle R1. The second height H2 of the top surface of the lifting resistance tooth 31 is less than the first height H1 of the top surface of the shift-up gear 210. The top surface of the lifting resistance tooth 31 has a second thickness D2 along the circumferential direction of the gear disc body 10, which represents the length of the top surface of the lifting resistance tooth 31 extending in the arc direction along the tooth top circle R2. The second thickness D2 of the top surface of the lifting resistance tooth 31 is less than the first thickness D1 of the shift-up gear top surface 210. The top surface of the lifting resistance tooth 31 has a second width W2 along the axial direction of the gear disc body 10, which represents the length of the top surface of the lifting resistance tooth 31 extending in the axial direction of the gear disc body 10. The second width W2 of the top surface of the lifting resistance tooth 31 is less than the first width W1 of the shift-up gear top surface 210. The distance between the top surface 31 of the lifting resistance tooth 30 and the first side surface 13 is smaller than the distance between the top surface 31 of the lifting resistance tooth 30 and the second side surface 14, so that the lifting resistance tooth 30 is offset toward the first side surface 13. In addition, in this embodiment, the top surface 31 of the lifting resistance tooth is offset in a direction away from the upshift promotion tooth 21.

[0027] The driving surface 32 and the driven surface 33 are located on opposite sides of the lifting resistance tooth 30 along the circumferential direction of the gear plate body 10, and are respectively connected to opposite ends of the top surface 31 of the lifting resistance tooth. The driven surface 33 is closer to the upshift promotion tooth 21 relative to the driving surface 32. The driving surface 32 has a first curvature, which represents the curvature of the driving surface 32; the driven surface 33 has a second curvature, which represents the curvature of the driven surface 33. In this embodiment, the first curvature is greater than the second curvature, which means that the driving surface 32 is more curved than the driven surface 33.

[0028] The first section 34 and the second section 35 are located on opposite sides of the resistance tooth 30 along the axial direction of the gear disc body 10, and are respectively connected to opposite ends of the top surface 31 of the resistance tooth. The first section 34 is connected to the first side surface 13, and the second section 35 is connected to the second side surface 14. The first section 34 has a first slope, which represents the degree of inclination of the first section 34 relative to the axial direction of the gear disc body 10. The second section 35 has a second slope, which represents the degree of inclination of the second section 35 relative to the axial direction of the gear disc body. In this embodiment, the first slope of the first section 34 is greater than the second slope of the second section 35, or it can be said that the first section 34 is more perpendicular to the axial direction of the gear disc body 10 than the second section 35.

[0029] According to the above structure, when the chain moves to the position of the lifting resistance tooth 30, since the lifting resistance tooth 30 is offset toward the first side surface, the top surface 31 of the lifting resistance tooth is smaller, the driven surface 33 is raised relative to the driving surface 32, and the second cut surface 35 is flatter than the first cut surface 34, the main part of the chain will fall on the back side of the lifting resistance tooth 30 and cannot be moved by the rear transmission, so that the chain can only perform the upshifting action when it moves to the next group of the upshifting promotion part 20. Therefore, the lifting resistance tooth 30 can limit the chain to perform the upshifting action only at the upshifting promotion part 20.

[0030] In summary, the bicycle sprocket upshift structure provided by the utility model can effectively limit the chain from upshifting on the upshift resistance tooth through the structure of the upshift resistance tooth adjacent to the upshift promotion tooth, thereby limiting the chain from upshifting in the upshift promotion portion, thereby maximizing the upshift efficiency.

[0031] The above are the preferred embodiments of the utility model and the technical principles used therein. For those skilled in the art, without departing from the spirit and scope of the utility model, any obvious changes such as equivalent transformation, simple replacement, etc. based on the technical solution of the utility model shall fall within the protection scope of the utility model.

Claims

1. A bicycle gear shifting structure, characterized in that: Contains: A gear disc body having a plurality of meshing teeth surrounding the outer peripheral surface of the gear disc body; an upshift promoting portion, disposed on the sprocket body and adjacent to the outer circumferential surface of the sprocket, for promoting a chain to move from the sprocket body to an adjacent smaller sprocket body; the upshift promoting portion comprises an upshift promoting tooth and an upshift promoting groove; the top of the upshift promoting tooth has an upshift tooth top surface; the upshift tooth top surface has a first height relative to the bottom of the upshift promoting tooth, the upshift tooth top surface has a first thickness along the circumferential direction of the sprocket body, and the upshift tooth top surface has a first width along the axial direction of the sprocket body; the upshift promoting groove is connected to the upshift promoting tooth; and an anti-lift tooth, disposed on the outer circumferential surface of the sprocket body and adjacent to the upshift promoting tooth, for preventing the chain from moving from the sprocket body to the adjacent smaller sprocket body; the top of the anti-lift tooth has an anti-lift tooth top surface; the anti-lift tooth top surface has a second height relative to the bottom of the anti-lift tooth, the anti-lift tooth top surface has a second thickness along the circumferential direction of the sprocket body, and the anti-lift tooth top surface has a second width along the axial direction of the sprocket body; Among them, the second height of the top surface of the anti-lift tooth is smaller than the first height of the top surface of the upshift tooth; the second thickness of the top surface of the anti-lift tooth is smaller than the first thickness of the top surface of the upshift tooth; the second width of the top surface of the anti-lift tooth is smaller than the first width of the top surface of the upshift tooth.

2. The bicycle gear shifting structure according to claim 1, characterized in that: The toothed disc body has a first side surface and a second side surface respectively on two opposite sides along the axial direction; the distance between the top surface of the resistance tooth and the first side surface is smaller than the distance between the top surface of the resistance tooth and the second side surface.

3. The bicycle gear shifting structure according to claim 2, characterized in that: The distance between the upshift tooth top surface and the first side surface is greater than the distance between the upshift tooth top surface and the second side surface.

4. The bicycle gear shifting structure according to claim 2, characterized in that: The lift-blocking tooth has a first section and a second section; the first section is connected to the first side surface of the toothed disc body; the second section is connected to the second side surface of the toothed disc body; the first section has a first slope relative to the axial direction of the toothed disc body, the second section has a second slope relative to the axial direction of the toothed disc body, and the first slope is greater than the second slope.

5. The bicycle gear shifting structure according to claim 1, characterized in that: The lift-blocking tooth has a driving surface and a driven surface on two opposite sides along the circumferential direction of the gear plate body; the driving surface and the driven surface are respectively connected to the opposite ends of the top surface of the lift-blocking tooth, and the driven surface is closer to the upshifting promoting tooth than the driving surface; wherein the driving surface has a first curvature, the driven surface has a second curvature, and the first curvature is greater than the second curvature.

6. The bicycle gear shifting structure according to claim 1, characterized in that: One end of the upshift promotion groove extends to below the upshift resistance tooth, and the upshift resistance tooth is not connected to the upshift promotion groove.

7. The bicycle gear shifting structure according to claim 1, characterized in that: The gear disc body is defined with a root circle, which is a virtual circle passing through the roots of a plurality of meshing teeth; the first height is the distance between the top surface of the upshift tooth and the root circle; the second height is the distance between the top surface of the resistance upshift tooth and the root circle.

8. The bicycle gear shifting structure according to claim 1, characterized in that: The top surface of the lift-blocking tooth is offset in a direction away from the upshift promoting tooth.

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