TWI705025B - Chainring of bicycle - Google Patents

Abstract

A chainring of a bicycle includes a main member having teeth, a plurality of first protrusions and a plurality of second protrusions. The first and the second protrusions are alternately arranged on the main member and corresponding to the teeth, respectively. Each of the first protrusions has a first main body, and each of the second protrusions has a second main body. Heights of the first main bodies of the first protrusions are greater than that of the second main bodies of the second protrusions. The first and the second protrusions are helpful to the stability of engagement of the chainring and a chain.

Description

Bicycle chainring structure

The invention relates to the technical field of a bicycle, in particular to a bicycle chainring structure.

Please refer to FIG. 1, the conventional bicycle chain 50 is composed of a plurality of pairs of inner plates 52 and a plurality of outer plates 54 which are alternately pivotally connected by pins 56. There is a space 58, 60 between each pair of inner plates 52 and each outer plate 54 respectively for the teeth 62 of a sprocket to be inserted, so that the sprocket can drive the chain 50. It is obvious that the width D1 of the space 58 between each pair of inner plates 52 is smaller than the width D2 of the space 60 between each pair of outer plates 54.

In order for the teeth 62 of the chainring to be smoothly combined with the chain 50, the tooth thickness of the teeth 62 is smaller than the width D1 of the space 58 between the inner plates 52. In other words, when the teeth 62 of the chainring are combined with the chain 50, there will be a gap between the teeth 62 and the inner plates 52. Since the width D2 of the space 60 between the outer plates 54 is greater than the width D1 of the space 58 between the inner plates 52, there will be a larger gap between the teeth 62 and the outer plates 54 .

Although these gaps are good for combining the teeth of the chainring with the chain, it is also easy for the teeth of the chainring to separate from the chain. Please refer to Fig. 2, during the shifting action, the chain 50 will receive a force perpendicular to the rotation direction of the chain (shown by the arrow in the figure). In detail, when the chain 50 meshes with the pinion (not shown in the figure) of the rear gear set, the chain 50 will receive a force toward the outside (the arrow toward the right of the figure). Head); and when the chain 50 is engaged with the large gear (not shown in the figure) of the rear gear set, the chain 50 will receive a force toward the inside (arrow toward the left of the figure). When the chain 50 receives this force, if the bicycle is in a fierce riding state at this time, the chain 50 will easily separate from the chainring.

The main purpose of the present invention is to provide a bicycle chainring structure, which can reduce the chance of the chainring separating from the chain during gear shifting.

In order to achieve the above-mentioned purposes and effects, the present invention discloses a bicycle chainring structure, which includes: a body with a plurality of teeth on the outer circumference; a plurality of first protrusions arranged on the body; each first protrusion The output piece has a first introduction part and a first body; the first introduction part is connected to the first body, and the first introduction part is closer to the outer end of the tooth than the first body; The height of the lead-in part gradually increases from the outer end of the first lead-in part to the end connected to the first body, and a plurality of second protruding parts are provided on the body; each second protruding part has a The second introduction part and a second body; the second introduction part is connected to the second body, and the second introduction part is closer to the outer end of the tooth than the second body; the height of the second introduction part From the outer end of the second lead-in portion to the end connected to the second body, it gradually enlarges; wherein, the first protrusions and the second protrusions are arranged in succession, and the first protrusions The output piece and the second protruding pieces respectively correspond to the teeth; the height of the first body of the first protruding piece is greater than the height of the second body of the second protruding piece.

With the above structure, the stability of the combination of the chainring and the chain can be improved, and the probability of the chain and the chainring being separated during shifting can be reduced.

10: chainring

12: crank

14: Outer side

16: inside

18: body

20: tooth

22: Lead-in section

24: The first protrusion

26: second protruding piece

28: The first body

30: The first introduction part

32: The second body

34: The second introduction part

36: chain

38: Outer panel

40: inner panel

42: recess

50: chain

52: inner panel

54: Outer panel

56: latch

58,60: space

62: tooth

D1, D2: space width

Figure 1 is a schematic diagram of a conventional chainring.

Figure 2 is a schematic diagram of the positive force when the conventional chainring is combined with the chain when shifting.

Figure 3 is a diagram of a chainring and crank of a preferred embodiment of the present invention.

Figure 4 is a partial perspective view of the inner surface of a chainring of a preferred embodiment of the present invention.

Figure 5 is a partial side view of a chainring of a preferred embodiment of the present invention.

Figure 6 is a partial perspective view of the outer surface of a chainring of a preferred embodiment of the present invention.

Figure 7 is a schematic diagram of the combination of a chainring and a chain in a preferred embodiment of the present invention.

Figure 8 is similar to Figure 7 and shows a schematic diagram of the chain being subjected to an outward positive force.

Figure 9 is similar to Figure 7 and shows a schematic diagram of the chain receiving inward positive force.

Figure 3 shows a chainring 10 and a crank 12 provided by a preferred embodiment of the present invention. One end of the crank 12 is connected to the center of the chainring 10. The chainring 10 has a body 18 with a plurality of teeth 20 on its outer circumference, which mesh with a chain (not shown). The outer end of each tooth 20 has an introduction section 22, and the height of the introduction section 22 gradually increases from the outer end of the tooth 20 toward the center of the sprocket 10. In this definition, the side of the crank 12 connected to the body 18 is defined as the outer side 14, and the other side is defined as the inner side 16. The structure described above is the same as that of the conventional chainring, so it will not be repeated here.

Please refer to FIG. 4 and FIG. 5, the main body 18 is provided with a plurality of first protrusions 24 and a plurality of second protrusions 26. The total number of the first protrusions 24 and the second protrusions 26 is the same as the number of the teeth 20, the first protrusions 24 and the second protrusions 26 are arranged in succession, and The first protruding pieces 24 and the second protruding pieces 26 respectively correspond to a tooth 20. The first protruding pieces 24 and the second protruding pieces 26 are respectively located on the inner side surface 16 and behind the introduction portion 22 of the teeth 20. In other words, the outer ends of the first protruding elements 24 and the second protruding elements 26 are separated from the outer ends of the teeth 20 by a predetermined distance.

Each first protruding member 24 has a first body 28 and a first introduction part 30 connected to one end of the first body 28. The first introduction part 30 is closer to the outer end of the tooth 20 than the first body part 28. The width and height of the first introduction portion 30 gradually increase from the outer end of the first introduction portion 30 to the end connected to the first body 28. The width of the first bodies 28 is smaller than the width of the teeth 20. Each second protruding member 26, similar to the first protruding members 24, has a second body 32 and a second introduction portion 34 connected to one end of the second body 32. The second introduction portion 34 is closer to the outer end of the tooth 20 than the second body portion 32. The width and height of the second introduction portion 34 gradually increase from the outer end of the second introduction portion 34 to the end connected to the second body portion 32. The height of the first body 28 of the first protruding members 24 is greater than the height of the second body 32 of the second protruding members 26.

It should be particularly noted here that the manufacturing method of the first protruding pieces 24 and the second protruding pieces 26 is to press the outer surface 14 of the main body 18 by pressing to make the inner surface 16 The protrusions form the first protrusions 24 and the second protrusions 26. Therefore, referring to FIG. 6, a number of recesses 42 are formed on the outer side surface 14 of the main body 18, corresponding to the first protruding elements 24 and the second protruding elements 26 respectively.

Please refer to Fig. 7, when the chainring 10 provided by this embodiment is combined with a chain 36, the teeth 20 with the first protruding member 24 will be inserted into the space between the two outer plates 38, and have the The teeth 20 of the second protruding member 26 will fit into the space between the two inner plates 40. Under normal conditions, the top surface of the first body portion 28 of the first protruding members 24 and the inner side surface of the outer plates 38 have a very small distance, and the second body of the second protruding members 26 There is a very small distance between the top surface of the portion 32 and the inner surfaces of the inner plates 40.

Please refer to Figure 8. When the bicycle is shifted to a high gear, that is, the chain 36 meshes with the small gear (not shown in the figure) of the rear gear set. At this time, the tension of the chain 36 is relatively small. , And the chain 36 will bear the positive force toward the outside of the chainring 10. The positive force will cause these internal The plate 40 is pressed against the second body 32 of the second protruding elements 26, and the outer plates 38 are pressed against the first body 28 of the first protruding elements 24. The chain 36 is supported by the first protruding elements 24 and the second protruding elements 26, so that the chain 36 is not easily separated from the chainring 10 when changing to a high gear.

Please refer to Figure 9, when the bicycle is shifted to a low gear, that is, the chain 36 meshes with the large gear (not shown in the figure) of the rear gear set. At this time, the tension of the chain 36 is relatively large. , And the chain 36 will bear the positive force toward the inner side of the chainring 10. Since the chainring 10 does not have a design of protrusions on the outer side surface 14, that is, a predetermined gap is still maintained between the inner plate 40 and the outer plate 38 of the chain 36 and the outer side surface of the chainring. Therefore, the outer plates 38 are supported on the outside of the gear, so that the inner plates 40 will not rub against the gear.

The above-mentioned embodiments are only illustrative of the technology and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with this technology can modify and change the above-mentioned embodiments without violating the technical principle and spirit of the present invention. Therefore, the protection scope of the present invention should be listed in the scope of patent application described later .

10: chainring

16: inside

18: body

20: tooth

22: Lead-in section

24: The first protrusion

26: second protruding piece

28: The first body

30: The first introduction part

32: The second body

34: The second introduction part

Claims (6)

A bicycle chainring structure, comprising: a body with a plurality of teeth on its outer circumference; a plurality of first protruding parts arranged on the body; each first protruding part has a first introduction part and a first A body; the first introduction part is connected to the first body, and the first introduction part is closer to the outer end of the tooth than the first body; the height of the first introduction part is determined by the height of the first introduction part The outer end gradually increases toward the end connected with the first body, and a plurality of second protruding parts are provided on the body; each second protruding part has a second introduction part and a second body; The second introduction part is connected to the second body, and the second introduction part is closer to the outer end of the tooth than the second body; the height of the second introduction part is from the outer end of the second introduction part to and One end of the second body connection gradually increases; wherein the first protruding parts and the second protruding parts are arranged in succession, and the first protruding parts and the second protruding parts are respectively arranged Corresponding to the teeth; the height of the first body of the first protrusions is greater than the height of the second body of the second protrusions; wherein the first protrusions and the second protrusions The pieces are arranged on the inner side of the body. For the bicycle chainring structure described in item 1 of the scope of patent application, the outer ends of the first introduction portion of the first protrusions and the outer ends of the second introduction portion of the second protrusions respectively correspond to The outer ends of the teeth are separated by a predetermined distance. For the bicycle chainring structure described in item 1 of the scope of patent application, the outer end of each tooth of the body has an introduction section, and the height of the introduction section gradually increases from the outer end of the tooth toward the center of the body. Large; the first protruding pieces and the second protruding pieces are respectively located behind the introduction section of the teeth. For example, the bicycle chainring structure described in item 1 of the scope of patent application, wherein the width of the first body of the first protrusions is smaller than the width of the teeth; the second body of the second protrusions The width is smaller than the width of the teeth. According to the bicycle chainring structure described in item 1 of the scope of patent application, the width of the first introduction portion of the first protruding member gradually increases from the outer end of the first introduction portion to the end connected to the first body Large; the height of the second introduction portion of the second protruding member gradually increases from the outer end of the second introduction portion to the end connected with the second body. For example, in the bicycle chainring structure described in item 1 of the scope of patent application, the body is located on the other side of the first protruding parts and the second protruding parts, and has a plurality of recesses corresponding to the The first protruding piece and the second protruding pieces.

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