TWM466071U - Bicycle sprocket mounting component and bicycle sprocket assembly having same - Google Patents

Description

Bicycle sprocket mounting member and bicycle sprocket assembly including the sprocket mounting member

The present invention relates to a bicycle sprocket attachment member for mounting a plurality of sprocket wheels to a bicycle hub, and a bicycle sprocket assembly including a bicycle sprocket attachment member.

In the rear hub of the bicycle, a sprocket assembly having a plurality of sprocket wheels having different numbers of teeth is mounted. For example, Patent Document 1 discloses a sprocket assembly in which a plurality of sprocket wheels of a plurality of sprocket wheels are combined and mounted. In the conventional sprocket assembly, one or a plurality of sprockets are fastened to the sprocket mounting member by rivets. Thus, a plurality of sprocket mounting holes through which the rivets can pass are formed in the sprocket mounting member.

[Advanced technical literature] [Patent Literature]

[Patent Document 1] JP-A-2008-189254

Since the sprocket is fastened by the rivet, when the sprocket attachment member is made of a material having low rigidity for the purpose of weight reduction, for example, when the tip end of the rivet is plastically deformed and caulked, it is necessary to sufficiently secure the chain. The strength near the sprocket mounting hole of the wheel mounting member.

An object of the present invention is to provide a sprocket mounting member and a sprocket assembly including the sprocket mounting member, and the strength of the sprocket mounting hole can be improved even if the sprocket is fastened to the sprocket mounting member by the rivet.

The bicycle sprocket mounting member of the present invention is used to mount a plurality of sprocket wheels to a bicycle hub. The bicycle sprocket attachment member includes a base portion, a sprocket attachment portion, and a reinforcing member. The base portion has a rotation axis and a hub engagement portion engageable with the bicycle hub. The sprocket attachment portion has at least one sprocket attachment hole to which the bicycle sprocket can be attached, and is disposed on the outer side in the diameter direction of the base portion. The reinforcing member is disposed at least in the vicinity of the sprocket mounting hole.

In the bicycle sprocket mounting member, a reinforcing member is disposed in at least a vicinity of the sprocket mounting hole. Thereby, the sprocket mounting hole is reinforced and the strength of the sprocket mounting hole is made high.

The reinforcing member can also be disposed in the sprocket mounting hole. In this case, the reinforcing member can directly reinforce the sprocket mounting hole.

The reinforcing member can also be tubular.

The reinforcing member can also be made of metal.

The reinforcing member can also be made of iron.

The sprocket mounting portion can also be made of non-metal. In this case, a material that can effectively reduce the weight of the sprocket mounting member can be selected.

The sprocket attachment portion may also be made of fiber reinforced resin. In this case, the sprocket mounting member can be kept strong and lightweight.

The base portion may also be made of non-metal. In this case, a material that can effectively reduce the weight of the sprocket mounting member can be selected.

The base portion may also be made of fiber reinforced resin. In this case, the sprocket mounting member can be kept strong and lightweight.

The base portion can also be made of light metal.

The axial length of the reinforcing member may also be the same as or shorter than the axial length of the sprocket mounting hole. In this case, even if the reinforcing member is attached to the sprocket mounting hole, the reinforcing member does not protrude from the sprocket mounting member, and the mounting accuracy of the sprocket can be maintained even if the reinforcing member is provided.

The sprocket attachment portion may have a plurality of arm portions that extend outward in the radial direction from the base portion and are disposed at intervals in the circumferential direction.

The bicycle sprocket assembly of the present invention includes the sprocket mounting member described above, a plurality of sprocket wheels having different numbers of teeth, and a sprocket mounting hole that can be inserted into the sprocket mounting member, and the plurality of sprocket wheels are fixed to the sprocket mounting member. Fastening member.

In the sprocket assembly, since the strength of the sprocket mounting hole can be prevented from being insufficient even if the sprocket is attached by the fastening member, the material to be attached to the sprocket can be freely selected.

With the present invention, the sprocket mounting hole is reinforced and the strength of the sprocket mounting hole can be prevented from being insufficient.

10‧‧‧ Rear sprocket assembly

11~21‧‧‧After sprocket

11a~21a‧‧‧Sprocket teeth

11b~20b‧‧‧ Inner Week

11c‧‧‧5th mounting hole

12c‧‧‧4th mounting hole

13c‧‧‧2nd mounting hole

14c‧‧‧3rd mounting hole

15c‧‧‧1st mounting hole

22‧‧‧1st sprocket mounting member

23‧‧‧Second sprocket mounting member

30‧‧‧Base section

32a‧‧‧arms

34‧‧‧Care Department

36‧‧‧3rd sprocket mounting hole

38‧‧‧3rd fastening member

40‧‧‧Base section

42‧‧‧Sprocket installation

42a‧‧‧arm

44‧‧‧Clock Department

46a‧‧‧1st sprocket mounting hole

46b‧‧‧2nd sprocket mounting hole

48a‧‧‧1st fastening member

48b‧‧‧2nd fastening member

80a‧‧‧1st reinforcing member

80b‧‧‧2nd reinforcing member

FIG. 1 is a front view of the rear sprocket assembly 10 including the rear sprockets 11 to 20.

Fig. 2 is a cross-sectional view showing the rear sprocket assembly 10 of the 2-A-2 cut surface of Fig. 1.

Fig. 3 is an exploded perspective view of the rear sprocket assembly 10 of Figs. 1 and 2 .

Fig. 4 is a front elevational view of the first sprocket mounting member 22 as seen from the side of the small-diameter rear sprocket 21.

Fig. 5 is a rear elevational view of the first sprocket mounting member 22 as seen from the side of the large-diameter rear sprocket 11.

Fig. 6 is a front elevational view of the first sprocket mounting member 22 to which the rear sprocket 13 is attached, as seen from the side of the small-diameter rear sprocket 21.

Fig. 7 is a front elevational view of the first sprocket mounting member 22 to which the rear sprocket 13 and 14 are attached as seen from the side of the small-diameter rear sprocket 21.

Fig. 8 is a front elevational view of the first sprocket mounting member 22 to which the rear sprocket 13, 13 and 15 are attached as seen from the side of the small-diameter rear sprocket 21;

Fig. 9 is a partially enlarged view of Fig. 8.

Fig. 10 is a cross-sectional view showing the cut surface of 12-12 in Fig. 8.

Fig. 11 is an end view of the periphery of the first sprocket attachment member 22 of Figs. 4 and 5 .

Fig. 12 is a front elevational view of the second sprocket attachment member 23 as seen from the side of the small-diameter rear sprocket 21.

Fig. 13 is a front elevational view of the second sprocket attachment member 23 to which the rear sprocket wheels 11, 12 are attached as seen from the side of the small-diameter rear sprocket 21;

The bicycle sprocket assembly of the present embodiment will be described below with reference to the drawings. Among the bicycle sprocket assemblies below, the rear sprocket assembly 10 attached to the rear hub of the bicycle will be described as an example.

(1) Overall configuration of the rear sprocket assembly 10

Fig. 1 is a front view of a rear sprocket assembly 10 including eleven rear sprockets 11 to 20. Fig. 2 is a cross-sectional view showing the rear sprocket assembly 10 of the 2-A-2 cut surface of Fig. 1. Fig. 3 is an exploded perspective view of the rear sprocket assembly 10 of Figs. 1 and 2 .

The rear sprocket assembly 10 includes a plurality of rear sprockets 11 to 21, three spacer rings 26 disposed between the rear sprockets 16 to 19, a first sprocket mounting member 22, and a second sprocket mounting member 23. And the lock nut 28.

The rear sprockets 11 to 21 are respectively formed to have a smaller diameter in sequence. That is, the rear sprocket 11 has the largest diameter and the rear sprocket 21 has the smallest diameter. Each of the rear sprockets 11 to 21 has sprocket teeth 11a to 21a formed on the outer peripheral side and inner peripheral portions 11b to 21b having irregularities formed on the inner peripheral side. The number of teeth of the rear sprockets 11 to 20 is 25, 23, 21, 19, 17, 16, 15, 14, 13, 12, and 11, respectively, as shown in Fig. 1 . However, the number of teeth is not limited to this.

The rear sprockets 16 to 21 are flywheels (not shown) that are individually attached to the rear hub (not shown) via the inner peripheral portions 16b to 21b. On the other hand, the rear sprocket wheels 13, 14, and 15 are integrally connected to each other in the axial direction centering on the central rotation axis A, and are attached to the first sprocket attachment member 22. The rear sprocket wheels 11 and 12 are integrally connected to each other in the axial direction and attached to the second sprocket mounting member 23.

Each of the rear sprockets 13 and 14 has a second attachment hole 13c and a third attachment hole 14c through which the second fastening member 48b to be described later is inserted. The rear sprocket 15 has a first attachment hole 15c through which the first fastening member 48a to be described later is inserted. Each of the rear sprockets 11 and 12 has a fourth mounting hole 12c and a fifth mounting hole 11c through which the third fastening member 38 to be described later is inserted.

The lock nut 28 is a member for attaching and fixing the rear sprocket assembly 10 to a flywheel (not shown).

(2) Construction of sprocket mounting members 22, 23

The configuration of the sprocket mounting members 22, 23 will be described below. First, the first sprocket mounting member 22 will be described below.

(2-1) First sprocket mounting member 22 (2-1-1) Overall Configuration of First Sprocket Mounting Member 22

Fig. 4 is a front elevational view of the first sprocket mounting member 22 as seen from the side of the small-diameter rear sprocket 21. Fig. 5 is a rear elevational view of the first sprocket mounting member 22 as seen from the side of the large-diameter rear sprocket 11. Fig. 6 is a front elevational view of the first sprocket mounting member 22 to which the rear sprocket 13 is attached, as seen from the side of the small-diameter rear sprocket 21. Figure 7 is a view from the side of the small diameter rear sprocket 21 A front view of the first sprocket mounting member 22 to which the rear sprocket wheels 13 and 14 are attached. Fig. 8 is a front elevational view of the first sprocket mounting member 22 to which the rear sprocket 13, 13 and 15 are attached as seen from the side of the small-diameter rear sprocket 21; Fig. 9 is a partially enlarged view of Fig. 8. Fig. 10 is a cross-sectional view showing the cut surface of 12-12 in Fig. 8. Fig. 11 is an end view of the periphery of the first sprocket attachment member 22 of Figs. 4 and 5 .

The first sprocket attachment member 22 is a member to which the rear sprocket 13 , 14 , and 15 are attached, and is a member adjacent to the second sprocket attachment member 23 .

As shown in FIG. 4 and FIG. 5, the first sprocket attachment member 22 includes a base portion 40, a sprocket attachment portion 42 having a plurality of arm portions 42a, and a plurality of the plurality of arm portions 42a. 1 and second sprocket mounting holes 46a, 46b. It is preferable that the arm portion 42a is three to six. In this embodiment, there are four arm portions 42a. The base portion 40 has a center portion of the center rotation axis A and an engagement portion 44 that can be engaged with a flywheel (not shown) of the bicycle rear hub (not shown) and has a concavo-convex portion. The plurality of arm portions 42a extend outward from the base portion 40 in the radial direction and are formed at intervals in the circumferential direction. The plurality of first sprocket attachment holes 46a and the second sprocket attachment holes 46b are holes for attaching the rear sprocket wheels 13, 14, and 15, and one set is provided for each arm portion 42a.

The first sprocket attachment member 22 is formed, for example, of a member made of a non-metal such as a fiber reinforced resin. As a fiber reinforced resin, for example, a carbon fiber reinforced resin. Other examples of the fiber-reinforced resin include a glass fiber reinforced resin, a boron fiber reinforced resin, a lanthanum carbide fiber reinforced resin, a steel fiber reinforced resin, and an aromatic polyamide fiber reinforced resin. Strong fiber The resin is a matrix resin in which a reinforcing fiber is impregnated with an unsaturated polyester resin, an epoxy resin, or a polypropylene. When the first sprocket mounting member 22 is formed of a fiber-reinforced resin, the strength can be increased and the weight thereof can be reduced.

In the present embodiment, for example, the base portion 40 and the sprocket attachment portion 42 are integrally formed of the same material. Therefore, the base portion 40 and the sprocket attachment portion 42 are formed of a member made of a non-metal such as a fiber-reinforced resin. Instead of this, the base portion 40 and the sprocket mounting portion 42 may be formed of a metal material. Further, the base portion 40 and the sprocket mounting portion 42 may be formed in different individuals. For example, the base portion 40 may be formed of a metal material, and the sprocket mounting portion 42 may be formed of a non-metal material such as fiber reinforced resin. As the metal material, for example, a low-density metal such as aluminum, titanium, or magnesium, or a light metal such as an alloy or a high-rigidity metal such as iron.

(2-1-2) Detailed structure of the arm portion 42a

The structure of the arm portion 42a of the sprocket mounting portion 42 will be further described below.

The first sprocket attachment hole 46a and the second sprocket attachment hole 46a are provided in each arm portion 42a. As shown in FIGS. 4 and 5, the first sprocket attachment hole 46a is an opening centered on the central axis C1, and the second sprocket attachment hole 46b is an opening centered on the central axis C2.

(a) Fixing of the rear sprocket 13, 14 and the first sprocket mounting member 22

As shown in FIG. 2 and the like, the second sprocket attachment hole 46b of the arm portion 42a communicates with the second attachment hole 13c and the third attachment hole 14c of the rear sprocket 13 and 14. The second fastening member 48b is inserted into the second sprocket attachment hole 46b, the second attachment hole 13c, and the third attachment hole 14c. 2nd in each arm 42 The sprocket attachment hole 46b, the second attachment hole 13c and the third attachment hole 14c of the rear sprocket 13 and 14 are fastened by penetrating the second fastening member 48b, thereby fixing the rear sprocket 13 and 14 to The first sprocket mounting member 22 (refer to Figs. 6 and 7). Therefore, the arm portion 42a composed of the protruding portion, the diametrical projection portion P3 of the rear sprocket 13 (refer to FIG. 6), and the diametrical projection portion P2 of the rear sprocket 14 (refer to FIG. 7) are fixed. Correspond to each other.

As the second fastening member 48b, for example, a rivet, a bolt, or the like is used. When the rivet is used as the second fastening member 48b, the both ends of the rear sprocket 13 and 14 and the first sprocket attachment member 22 are plastically deformed and caulked as shown in Fig. 2 and the like.

(b) Fixing of the rear sprocket 15 and the first sprocket mounting member 22

As shown in FIG. 2 and the like, the first sprocket attachment hole 46a of the arm portion 42a communicates with the first attachment hole 15c of the rear sprocket 15. The first fastening member 48a is inserted into the first sprocket attachment hole 46a and the first attachment hole 15c. The first sprocket attachment hole 46a of each arm portion 42 and the first attachment hole 15c of the rear sprocket 15 are fastened by penetrating the first fastening member 48a, thereby fixing the rear sprocket 15 to the first one. The sprocket mounting member 22 (refer to Fig. 8). Therefore, the arm portion 42a composed of the protruding portion and the protruding portion P1 in the radial direction of the rear sprocket 15 (refer to Fig. 8) are fixed to each other.

As the first fastening member 48a, for example, a rivet, a bolt, or the like is used. In the case where the rivet is used as the first fastening member 48a, the both ends of the rear sprocket 15 and the first sprocket attachment member 22 are plastically deformed and caulked as shown in Fig. 2 and the like.

(c) reinforcing member 80

As shown in FIG. 2 and FIG. 3, the first reinforcing member 80a is provided on the inner circumferential surface of the first sprocket attachment hole 46a of the arm portion 42a. Similarly, as shown in FIG. 2, FIG. 3, and FIG. 10, the second reinforcing member 80b is provided on the inner circumferential surface of the second sprocket attachment hole 46b of the arm portion 42a. The first reinforcing member 80a and the second reinforcing member 80b are included in the reinforcing member 80.

When the rivet is used as the first fastening member 48a, the first fastening member 48a has the main body portion 48c, the first end portion 48d, and the first fastening member 48a before being attached to the first sprocket attachment hole 46a and the first attachment hole 15c. The second end portion 48e. The main body portion is a portion through which the first sprocket attachment hole 46a and the first attachment hole 15c are inserted. The first end portion is formed to be larger than the main body portion before being attached to the first sprocket mounting hole 46a and the first mounting hole 15c. Therefore, the first end portion of the first fastening member 48a does not penetrate the first sprocket attachment hole 46a and the first attachment hole 15c. On the other hand, the second end portion penetrates the first sprocket attachment hole 46a and the first attachment hole 15c having the same size as the main body portion before being attached to the first sprocket attachment hole 46a and the first attachment hole 15c. Therefore, in the first fastening member 48a, the main body portion is inserted into the first sprocket attachment hole 46a and the first attachment hole 15c from the second end portion side. At this time, the first end portion is not penetrated by the first sprocket attachment hole 46a and the first attachment hole 15c, and is locked at the end of the first attachment hole 15c. Next, in a state where the first end portion is locked to the end portion of the first attachment hole 15c, the second end portion is plastically deformed and caulked. When the second end portion of the first fastening member 48a is caulked, the main body portion of the first fastening member 48a expands, so that the inner circumferential surface of the first sprocket attachment hole 46a is pressed. In the above embodiment, the first reinforcing member 80a is provided on the inner circumferential surface of the first sprocket attachment hole 46a, and the first reinforcing member 80a Withstand the pressure caused by the caulking. Therefore, the first sprocket attachment hole 46a is reinforced by the first reinforcing member 80a, and the strength of the first sprocket attachment hole 46a is increased.

The length of the first reinforcing member 80a in the axial direction is the same as the length of the first sprocket mounting hole 46a in the axial direction. Alternatively, the length of the first reinforcing member 80a in the axial direction is shorter than the length of the first sprocket mounting hole 46a in the axial direction. When the length of the first reinforcing member 80a in the axial direction is short, even if the first reinforcing member 80a is attached to the first sprocket mounting hole 46a, the first reinforcing member 80a does not come into contact with the sprocket 15, even if the first reinforcing member is provided. The member 80a can also maintain the mounting accuracy of the sprocket 15.

The first reinforcing member 80a and the second reinforcing member 80b are formed, for example, in a tubular shape along the inner circumferential surface of the first sprocket attachment hole 46a and the second sprocket attachment hole 46b. However, the first reinforcing member 80a and the second reinforcing member 80b are formed to have a shape along the inner circumferential surface of the first sprocket attachment hole 46a and the second sprocket attachment hole 46b, and are not limited to a tubular shape. The first reinforcing member 80a and the second reinforcing member 80b may not be formed on the inner circumferential surface of the first sprocket attachment hole 46a and the second sprocket attachment hole 46b, and may be formed on the inner circumferential surface. When the first and second reinforcing members 80a and 80b are formed along the first and second sprocket attachment holes 46a and 46b, the sprocket attachment hole 46 can be directly reinforced. The first reinforcing member 80a and the second reinforcing member 80b may be disposed in the vicinity of at least the first sprocket mounting hole 46a and the second sprocket mounting hole 46b.

The material of the first reinforcing member 80a and the second reinforcing member 80b is, for example, a metal such as iron. If it is a metal such as iron, it can be effectively used as a reinforcing member. 80, the strength of the sprocket mounting hole 46 can be improved. In place of this, the material of the first reinforcing member 80a and the second reinforcing member 80b may be a non-metallic material such as a light metal or a ceramic, a resin, or a carbon-reinforced resin as long as it has strength as a reinforcing member.

Since the second reinforcing member 80b has the same structure and operational effects as those of the first reinforcing member 80a, detailed description thereof will be omitted. The strength of the second sprocket attachment hole 46b is increased by the second reinforcing member 80b.

(d) Relationship between the first sprocket mounting hole 46a and the second sprocket mounting hole 46b

As shown in FIG. 4, FIG. 5, and the like, the first sprocket attachment hole 46a and the second sprocket attachment hole 46b are disposed apart from each other with a predetermined offset in the circumferential direction around the central rotation axis A. In this case, as shown in FIG. 10, the first fastening member 48a and the second fastening member 48b partially overlap each other in the radial direction with respect to the central rotation axis A. More specifically, the distance between the outermost end in the diameter direction of the first fastening member 48a and the central rotation axis A is larger than the distance between the innermost end of the second fastening member 48b in the radial direction and the central rotation axis A. The arm portion 42a of the first sprocket attachment hole 46a and the second sprocket attachment hole 46b is disposed in this manner, and the length L in the diameter direction is smaller than that of the conventional sprocket attachment member as shown in Fig. 4, and on the other hand, The width A in the circumferential direction is larger than the conventional sprocket mounting member. By reducing the length L in the radial direction, the first sprocket mounting member 22 can be made lighter and smaller in the diameter direction. According to this simple structure, it is possible to easily manufacture the first sprocket attachment member 22 that is lightweight and compact.

As shown in FIGS. 4 and 10, the arm portion 42a has a stepped shape in order to arrange the rear sprocket wheels 14, 15 in the axial direction. Arm 42a has a first arm portion 52, a second arm portion 54, and an outer surface 50. The first arm portion 52 is a portion in which the first sprocket attachment hole 46a is provided, and the second arm portion 54 is a portion in which the second sprocket attachment hole 46b is provided. The first arm portion 52 and the second arm portion 54 have different heights in the axial direction. The outer surface 50 is a surface that is outward in the radial direction between the first arm portion 52 and the second arm portion 54 as shown in FIGS. 10 and 11 and the like.

The rear sprocket 15 is placed in contact with the first arm portion 52, and the first fastening member 48a is inserted into the first sprocket attachment hole 46a and fixed to the first arm portion 52. The rear sprocket 14 is placed in contact with the second arm portion 54, and the second fastening member 48b is inserted into the second sprocket attachment hole 46b and fixed to the second arm portion 54. Therefore, only the outer surfaces 50 of the rear sprockets 14 and 15 are disposed in the axial direction.

On the other hand, as shown in FIG. 9 and FIG. 10, the outermost end of the first sprocket attachment hole 46a in the radial direction and the distance from the central rotation axis A are the first radial direction distance R1. The innermost end in the radial direction of the diametrical projection portion P2 of the rear sprocket 14 and the distance from the central rotation axis A are the second radial direction distance R2. The second diameter direction distance R2 is smaller than the first diameter direction distance R1. Therefore, the diameter-direction protruding portion P2 of the rear sprocket 14 and the outermost end in the radial direction of the first sprocket mounting hole 46a are repeated in the radial direction centering on the central rotating shaft A. By the repeated structure, the length L in the diameter direction (refer to FIG. 4) is reduced, and the rear sprocket 14, 15 and/or the first sprocket attachment member 22 can be made lighter.

(2-2) Second sprocket mounting member 23

Next, the second sprocket attachment member 23 will be described below.

Fig. 12 is a front elevational view of the second sprocket attachment member 23 as seen from the side of the small-diameter rear sprocket 21. Fig. 13 is a front elevational view of the second sprocket attachment member 23 to which the rear sprocket wheels 11, 12 are attached as seen from the side of the small-diameter rear sprocket 21;

The second sprocket attachment member 23 is a member to which the rear sprocket wheels 11 and 12 are attached, and is located at the outermost side in the axial direction of the rear sprocket assembly 10.

The second sprocket attachment member 23 includes a base portion 30, a sprocket attachment portion 32 having a plurality of arm portions 32a, and a plurality of third sprocket attachment holes 36 provided in the plurality of arm portions 32a. The base portion 30 has a center rotation axis A and an engagement portion 34 that is engageable with a flywheel (not shown) of a bicycle rear hub (not shown) and has a concavo-convex portion. The plurality of arm portions 32a extend outward from the base portion 30 in the radial direction and are formed at intervals in the circumferential direction. The plurality of third sprocket mounting holes 36 are holes for attaching the rear sprocket wheels 11, 12, and are provided in the respective arm portions 32a.

As shown in Fig. 2, the third sprocket attachment hole 36 of each arm portion 32a communicates with the fourth mounting hole 12c and the fifth mounting hole 11c of the rear sprocket wheels 11 and 12. The third fastening member 38 is inserted into the third sprocket attachment hole 36. The third sprocket attachment hole 36 of each arm portion 32a and the fourth attachment hole 12c and the fifth attachment hole 11c of the rear sprocket 11 and 12 are fastened by penetrating the third fastening member 38. The rear sprocket wheels 11 and 12 are fixed to the second sprocket mounting member 23 as shown in Fig. 2 and Fig. 13 and the like.

As the third fastening member 38, for example, a rivet, a bolt, or the like is used.

In the present embodiment, the second sprocket attachment member 23 is formed of a light metal such as aluminum.

<Other Embodiments>

The above description of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit and scope of the invention. In particular, the plural embodiments and modifications described in the present specification can be arbitrarily combined as needed.

(a) In the above embodiment, the first reinforcing member 80a and the second reinforcing member are provided on the inner circumferential surfaces of the first sprocket attachment hole 46a and the second sprocket attachment hole 46b of the first sprocket attachment member 22, respectively. 80b. However, the reinforcing member 80 may be provided only in any of the first sprocket attachment hole 46a and the second sprocket attachment hole 46b. However, it is preferable that the first sprocket attachment hole 46a and the second sprocket attachment hole 46a and the second sprocket attachment hole 46b are provided with the first sprocket attachment hole 46a and the second sprocket attachment hole 46b, respectively. 2 The strength of both of the sprocket mounting holes 46b.

(b) In the above embodiment, the reinforcing member 80 is not provided in the third sprocket attachment hole 36 of the second sprocket attachment member 23. However, similarly to the first sprocket attachment hole 46a of the first sprocket attachment member 22 of the above-described embodiment, the reinforcing member 80 may be provided also in the third sprocket attachment hole 36.

Similarly to the first reinforcing member 80a and the second reinforcing member 80b, the reinforcing member 80 of the third sprocket mounting hole 36 is formed into a tubular shape along the inner circumferential surface of the third sprocket mounting hole 36, for example. The shape of the reinforcing member 80 is not limited to a tubular shape as long as it is formed along the inner circumferential surface of the third sprocket attachment hole 36. The material of the reinforcing member 80 may be a metal such as iron or a non-metal member such as a resin similar to the above-described embodiment.

(c) In the present embodiment, the second sprocket attachment member 22 is formed of a light metal such as aluminum. However, the second sprocket attachment member 22 may be formed of a non-metal such as carbon fiber reinforced resin similarly to the first sprocket attachment member 22. Similarly to the first sprocket attachment member 22, the second sprocket attachment member 23 may be formed integrally with the sprocket attachment portion 32 in the same material. Alternatively, the base portion 30 and the sprocket mounting portion 32 may be formed by different individuals. For example, the base portion 30 may be formed of a metal material, and the sprocket mounting portion 32 may be formed of a non-metal material such as fiber reinforced resin.

(d) In the above embodiment, the sprocket is described as an example of the sprocket, and the present invention is also applicable to the front sprocket.

13, 14, ‧ ‧ rear sprocket

13a, 14a, 15a‧‧‧ sprocket

13b, 14b, 15b‧‧‧ inner week

13c‧‧‧2nd mounting hole

14c‧‧‧3rd mounting hole

15c‧‧‧1st mounting hole

22‧‧‧1st sprocket mounting member

40‧‧‧Base section

42‧‧‧Sprocket installation

44‧‧‧Clock Department

46a‧‧‧1st sprocket mounting hole

46b‧‧‧2nd sprocket mounting hole

48a‧‧‧1st fastening member

48b‧‧‧2nd fastening member

48c‧‧‧ Main body 48c

48d‧‧‧1st end 48d

48e‧‧‧2nd end 48e

50‧‧‧Outer surface 50

52‧‧‧1st arm 52

54‧‧‧2nd arm 54

80b‧‧‧2nd reinforcing member

Claims (26)

A bicycle sprocket mounting member for mounting a plurality of sprocket wheels to a bicycle hub; comprising: a base portion, a sprocket mounting portion, and a reinforcing member; the base portion having: a rotating shaft center, and a hub engagement portion that engages with the bicycle hub; the sprocket attachment portion has at least one sprocket attachment hole to which the bicycle sprocket can be attached, and is disposed outside the base portion in a diameter direction; the reinforcement member is disposed At least in the vicinity of the sprocket mounting hole. The bicycle sprocket mounting member according to claim 1, wherein the reinforcing member is disposed in the sprocket mounting hole. A bicycle sprocket mounting member according to claim 2, wherein the reinforcing member is tubular. The bicycle sprocket mounting member according to claim 1, wherein the reinforcing member is made of metal. A bicycle sprocket mounting member according to claim 4, wherein the reinforcing member is made of iron. The bicycle sprocket mounting member according to claim 1, wherein the sprocket mounting portion is made of a non-metal. The bicycle sprocket mounting member according to claim 6, wherein the sprocket mounting portion is made of fiber reinforced resin. The bicycle sprocket mounting member according to claim 1, wherein the base portion is made of a non-metal. Bicycle sprocket installation structure as claimed in item 8 of the patent application And the base portion is made of fiber reinforced resin. The bicycle sprocket mounting member according to claim 1, wherein the base portion is made of light metal. The bicycle sprocket mounting member according to claim 1, wherein the length of the reinforcing member in the axial direction is the same as or shorter than the axial length of the sprocket mounting hole. In the bicycle sprocket attachment member according to the first aspect of the invention, the sprocket attachment portion includes a plurality of arm portions that extend outward in the radial direction from the base portion and are disposed at intervals in the circumferential direction. A bicycle sprocket assembly comprising: a sprocket mounting member according to claim 1 of the patent scope, the plurality of sprocket wheels having different numbers of teeth, and a sprocket mounting hole that can be inserted into the sprocket mounting hole to fix the plurality of sprocket wheels A fastening member for the sprocket mounting member described above. The bicycle sprocket assembly according to claim 13, wherein the fastening member is a rivet. The bicycle sprocket assembly according to claim 13, wherein the fastening member is a bolt. The bicycle sprocket assembly according to claim 13, wherein the reinforcing member is disposed in the sprocket mounting hole. The bicycle sprocket assembly according to claim 13, wherein the reinforcing member is tubular. The bicycle sprocket assembly according to claim 13, wherein the reinforcing member is made of metal. The bicycle sprocket assembly according to claim 18, wherein the reinforcing member is made of iron. The bicycle sprocket assembly according to claim 13, wherein the sprocket mounting portion is made of a non-metal. The bicycle sprocket assembly according to claim 20, wherein the sprocket attachment portion is made of fiber reinforced resin. The bicycle sprocket assembly according to claim 13, wherein the base portion is made of a non-metal. The bicycle sprocket assembly according to claim 22, wherein the base portion is made of fiber reinforced resin. The bicycle sprocket assembly according to claim 13, wherein the base portion is made of light metal. The bicycle sprocket assembly according to claim 13, wherein the length of the reinforcing member in the axial direction is the same as or shorter than the axial length of the sprocket mounting hole. The bicycle sprocket assembly according to claim 13, wherein the sprocket attachment portion has a plurality of arm portions that extend outward in the radial direction from the base portion and are arranged at intervals in the circumferential direction.