TW202144228A - Sprocket for human driving vehicle for achieving required stiffness and light weight - Google Patents

Abstract

The present invention provides a sprocket for human driving vehicle providing required stiffness and light weight. The sprocket for human driving vehicle of the present invention includes: a plurality of metal sprocket teeth, a shell member having a first configuration portion and made of first carbon material containing at least one first carbon fiber with first fiber length, a filling member disposed in the first configuration portion of the shell member and made of second carbon material containing at least one second carbon fiber with second fiber length, and a foaming member disposed in the first configuration portion of the shell member.

Description

Sprockets for Human Driven Vehicles

The present invention relates to a sprocket for a human-driven vehicle.

For example, Patent Document 1 discloses a sprocket for a human-powered vehicle. The sprocket for a human-powered vehicle of Patent Document 1 includes carbon fibers and a foamed member. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2008-001287

[The problem to be solved by the invention]

An object of the present invention is to provide a sprocket for a human-driven vehicle having the required rigidity and light weight. [means to solve the problem]

The sprocket for a human-powered vehicle according to the first aspect of the present invention includes a plurality of sprocket teeth made of metal, and a first carbon material having a first arrangement portion and including at least one first carbon fiber having a first fiber length. a casing member, a filling member made of a second carbon material disposed in the first disposition portion of the casing member and containing at least one second carbon fiber having a second fiber length, and disposed in the first disposition portion of the casing member foam components. The sprocket for a human-powered vehicle according to the first aspect described above includes a shell member made of a first carbon material including at least one first carbon fiber having a first fiber length, and a shell member including at least one first carbon fiber having a second fiber length. Two carbon fiber filling members made of a second carbon material, and a foam member disposed in the first disposition portion. Therefore, the casing member made of the first carbon material and the filling member made of the second carbon material can each contain carbon fibers having a fiber length suitable for design requirements. Therefore, required rigidity and weight reduction can be provided.

According to the sprocket for a human-powered vehicle according to the second aspect of the first aspect, the first fiber length is greater than the second fiber length. According to the human-powered vehicle sprocket of the second aspect, the rigidity of the casing member can be improved because the first fiber length is longer than the second fiber length. Furthermore, since the second fiber length is smaller than the first fiber length, the filling member can be appropriately arranged in the first arrangement portion.

According to the sprocket for a human-driven vehicle of the third aspect of the first or second aspect, the at least one first carbon fiber includes a plurality of first carbon fibers, and the at least one second carbon fiber includes a plurality of second carbon fibers. With the sprocket for a human-driven vehicle of the third aspect, since at least one first carbon fiber includes a plurality of first carbon fibers, and at least one second carbon fiber includes a plurality of second carbon fibers, it is easy to form the shell member and the filling member.

According to the sprocket for a human-powered vehicle according to the fourth aspect of any one of the first to third aspects, the filling member has a second arrangement portion, and the foam member is arranged in the second arrangement portion of the filling member. . According to the sprocket for a human-driven vehicle of the above-mentioned fourth aspect, since the foam member is arranged in the second arrangement portion of the filling member, it is easy to arrange the foam member at a desired position.

The sprocket for a human-powered vehicle according to the fifth aspect of any one of the first to fourth aspects is provided with a sprocket ring member including an annular base portion and a sprocket from the above-mentioned The base portion includes the plurality of sprocket teeth extending toward the radially outer side of the sprocket for a human-powered vehicle with respect to the center axis of rotation. The sprocket for a human-driven vehicle according to the fifth aspect is provided with a sprocket ring member, and the above-mentioned sprocket ring member includes: an annular base and a plurality of sprocket teeth; The combination of the base, the shell member, the filling member, and the foamed member can produce a sprocket for a human-powered vehicle. Therefore, the manufacturing efficiency is excellent.

According to the sprocket for a human-driven vehicle of the sixth aspect of the fifth aspect, the sprocket ring member is fixed to the filling member by a heating and pressing process. According to the sprocket for a human-driven vehicle of the sixth aspect, since the sprocket ring member is fixed to the filling member by the heating and pressing process, the sprocket for a human-driven vehicle can be manufactured with a small number of processes. Therefore, the manufacturing efficiency is excellent.

According to the seventh aspect of the human-powered vehicle sprocket of the fifth or sixth aspect, the base portion of the sprocket ring member has at least one hole for arranging the filling member. According to the sprocket for a human-driven vehicle of the seventh aspect, since the filling member is disposed in at least one hole portion of the annular base portion of the sprocket ring member, the sprocket ring member can be stably fixed to the filling member. member.

According to the sprocket for a human-powered vehicle of the eighth aspect of the seventh aspect, the at least one hole portion of the base portion includes a plurality of hole portions. According to the above-mentioned eighth aspect of the human-powered vehicle sprocket, since the at least one hole portion of the annular base portion includes a plurality of hole portions, it is possible to more stably connect the annular base portion to the case where the annular base portion includes at least one hole portion. The sprocket ring member is fixed to the filling member.

According to the sprocket for a human-powered vehicle of the ninth aspect of any one of the first to eighth aspects, the first fiber length of the at least one first carbon fiber is 25 mm or more and 510 mm or less. According to the sprocket for a human-driven vehicle of the ninth aspect, the first fiber length of at least one of the first carbon fibers is 25 mm or more and 510 mm or less, so that the rigidity of the housing member made of the first carbon material can be suppressed from decreasing.

According to the tenth aspect of the sprocket for a human-powered vehicle according to any one of the first to ninth aspects, the second fiber length of the at least one second carbon fiber is 5 mm or more and 24 mm or less. According to the sprocket for a human-driven vehicle of the tenth aspect, since the second fiber length of at least one of the second carbon fibers is 5 mm or more and 24 mm or less, the rigidity of the filling member made of the second carbon material can be suppressed from decreasing and the filling member can be suppressed. weight increase.

According to the bicycle crank assembly of the eleventh aspect of any one of the first to tenth aspects, the plurality of sprocket teeth include: at least one first tooth having a first chain engagement width; At least one second tooth of the chain engagement width; the first chain engagement width and the second chain engagement width are widths extending in the axial direction relative to the rotation center axis of the sprocket for a human-powered vehicle The said first chain engagement width is larger than the said 2nd chain engagement width. With the sprocket for a human-driven vehicle of the eleventh aspect, the plurality of sprocket teeth include: at least one first tooth and at least one second tooth whose chain engagement widths are different from each other; therefore, the human-driven vehicle can be effectively held Use a chain.

According to the sprocket for a human-powered vehicle according to the eleventh aspect and the twelfth aspect, the engagement width of the first chain is smaller than the outer chain defined between the pair of opposite outer links of the human-driven vehicle chain. The piece space is larger than the inner link space defined between a pair of inner links facing each other of the human-powered vehicle chain, and the second chain engagement width is smaller than the inner link space. With the above-mentioned eleventh aspect of the human-driven vehicle sprocket, the first chain engaging width is smaller than the outer link space and larger than the inner link space, and the second chain engaging width is smaller than the inner link space, so it can be effectively maintained. Chains for human powered vehicles. [Inventive effect]

The sprocket for a human-powered vehicle of the present invention has required rigidity and can be reduced in weight.

<First Embodiment>

The sprocket 30 for a human-powered vehicle according to the first embodiment will be described with reference to FIGS. 1 to 13 . The human-powered vehicle has at least one wheel, and is a vehicle that can be driven at least by human-powered driving force. Examples of human-powered vehicles include mountain bikes, road bikes, city bikes, cargo bikes, hand-operated bikes, and recumbent bikes. There is no limit to the number of wheels the human-powered vehicle has. The human-powered vehicle includes, for example, a unicycle and a vehicle having three or more wheels. The human-driven vehicle is not limited to a vehicle driven only by human-driven power. The human-powered vehicle includes an electric bicycle (E-bike) propelled by not only human-powered driving force but also the driving force of an electric motor. Electric bicycles, including electric-assisted bicycles that are propelled by electric motors. In the following embodiments, the human-powered vehicle will be described as a bicycle.

As shown in FIG. 1 , the crank assembly 10 for a human-powered vehicle includes a sprocket 30 for a human-powered vehicle, a crank arm member 12 , and a crankshaft 20 . The crank arm member 12 is attached to the crank arm member 12 by the attachment member 14 . For example, the mounting member 14 is a bolt.

The crank arm member 12 includes a crank arm 16 and a sprocket attachment portion 18 . The sprocket mounting portion 18 extends radially outward X1 from the rotation center axis 20A of the crankshaft 20 . The crank arm member 12 preferably has a plurality of sprocket mounting portions 18 . One of the plurality of sprocket attachment portions 18 and the plurality of crank arm attachment portions 32 includes a hole portion, and the other of the plurality of sprocket attachment portions 18 and the plurality of crank arm attachment portions 32 includes a female thread portion 32A. In the present embodiment, the plurality of sprocket attachment portions 18 include hole portions, and the plurality of crank arm attachment portions 32 include female screw portions 32A (refer to FIG. 4 ). The sprocket 30 for a human-driven vehicle preferably has a crank arm mounting portion 32 . The crank arm attachment portion 32 is attached to the sprocket attachment portion 18 via the attachment member 14 . In the present embodiment, the bolts of the mounting member 14 are inserted into the holes of the plurality of sprocket mounting portions 18 , and are screwed into the female screw portions 32A of the plurality of crank arm mounting portions 32 , so that the crank arm member 12 is connected to the The sprockets 30 for the human-driven vehicle are attached to each other. The crank assembly 10 for a human-driven vehicle may have a plurality of sprockets 30 for a human-driven vehicle. When the crank assembly 10 for a human-driven vehicle includes plural sprockets 30 for a human-driven vehicle, each crank arm mounting portion 32 of the plural sprockets 30 for a human-driven vehicle is attached to the crank arm member 12 via the mounting member 14 . For example, the crank assembly 10 for a human-driven vehicle may include two or three sprockets 30 for a human-driven vehicle.

As shown in FIGS. 2 and 8 , the sprocket 30 for a human-powered vehicle includes a plurality of sprocket teeth 34 made of metal, a casing member 36 made of a first carbon material, and a filling member 38 made of a second carbon material. , the foam member 40 . The shell member 36 has the first arrangement portion 42 and includes at least one first carbon fiber 44 having a first fiber length. The filling member 38 is arranged in the first arrangement portion 42 of the casing member 36 and includes at least one second carbon fiber 46 having a second fiber length. The foam member 40 is arranged in the first arrangement portion 42 of the casing member 36 . The first fiber length is different from the second fiber length. The first fiber length is preferably greater than the second fiber length.

As shown in FIGS. 1 , 3 , 4 , and 8 , the casing member 36 includes a first casing member 48 and a second casing member 50 . The first housing member 48 includes an outer surface portion 48A of one of the axial directions of the rotation center axis 20A of the crankshaft 20 in the sprocket 30 for a human-driven vehicle. The second housing member 50 includes an outer surface portion 50A on the other side in the axial direction of the rotation center axis 20A of the crankshaft 20 in the sprocket 30 for a human-driven vehicle. In the present embodiment, the second housing member 50 includes an end face on the side opposite to the frame of the manual vehicle in the axial direction of the rotation center axis 20A of the crankshaft 20 of the sprocket 30 for the manual vehicle. The first housing member 48 includes an annular portion 48C and a plurality of convex portions 48D protruding from the annular portion 48C toward the radially inner side X2 with respect to the rotation center axis 20A. The second housing member 50 includes an annular portion 50C and a plurality of convex portions 50D protruding from the annular portion 50C toward the radially inner side X2 relative to the rotation center axis 20A. As shown in FIGS. 5 and 8 , in the present embodiment, the inner peripheral surface of the annular portion 48C of the first casing member 48 is curved toward the second casing member 50 . Instead, the inner peripheral portion of the second casing member 50 may be bent toward the first casing member 48 . As shown in FIGS. 3 and 4 , the plural convex portions 48D and the plural convex portions 50D are provided at the same positions in the circumferential direction of the casing member 36 . The crank arm mounting part 32 is provided between each convex part 48D and each convex part 50D, respectively. In the present embodiment, the crank arm attachment portion 32 includes a nut 32B, and the nut 32B is provided with a female screw portion 32A. The nut 32B is preferably made of metal material. Nut 32B is preferably supported by filler member 38 .

As shown in FIGS. 9 to 11 , at least one first carbon fiber 44 includes plural first carbon fibers 44 , and at least one second carbon fiber 46 includes plural second carbon fibers 46 .

The first casing member 48 and the second casing member 50 are each formed using first carbon fiber sheets in which the extension directions of the plurality of first carbon fibers 44 are arranged in a single direction. The first carbon fiber sheet may further include a plurality of third carbon fibers 52 . The plurality of third carbon fibers 52 are arranged in a direction intersecting with the extending direction of the plurality of first carbon fibers 44 . The third fiber length of the plurality of third carbon fibers 52 is preferably shorter than the first fiber length of the plurality of first carbon fibers 44 . In each of the first casing member 48 and the second casing member 50 , the plurality of first carbon fibers 44 are arranged to extend along the circumferential direction R of the first casing member 48 , for example. The plurality of first carbon fibers 44 are arranged side by side in the radial direction X of the first casing member 48 and the second casing member 50, for example. The plurality of first carbon fibers 44 may be stacked in the thickness direction of the first casing member 48 and the second casing member 50 . Although FIG. 9 schematically shows the first shell member 48 in which two layers of the first carbon fibers 44 and one layer of the third carbon fibers 52 are stacked, the first shell member 48 may have three or more layers of the first carbon fibers stacked thereon. 44 and 2 or more layers of third carbon fiber 52. Although FIG. 10 schematically shows the second shell member 50 in which two layers of the first carbon fibers 44 and one layer of the third carbon fibers 52 are stacked, the second shell member 50 may have three or more layers of the first carbon fibers stacked thereon. 44 and 2 or more layers of third carbon fiber 52. It is preferable that the 1st case member 48 and the 2nd case member 50 contain resin material. The resin material contains epoxy resin, for example. The resin material is the base material of the first carbon fiber sheet.

The first fiber length of at least one of the first carbon fibers 44 is preferably 25 mm or more and 510 mm or less. The first fiber length of the longest first carbon fiber 44 among the plurality of first carbon fibers 44 is preferably 25 mm or more and 510 mm or less. The plurality of first carbon fibers 44 may include first carbon fibers 44 having a first fiber length of less than 25 mm. The fiber diameter of the at least one first carbon fiber 44 is, for example, 7 μm. The at least one first carbon fiber 44 is arranged, for example, along the circumferential direction of the casing member 36 . The first fiber length of the at least one first carbon fiber 44 is, for example, equal to or less than the circumference of the outer peripheral portion of the shell member 36 .

The filling member 38 is preferably formed using plural second carbon fiber sheets including plural second carbon fibers 46 . The second carbon fiber sheet is, for example, a rectangular chopped material. One side of the second carbon fiber sheet is preferably smaller than the smallest width LX (refer to FIG. 3 ) among the widths in the radial direction X of the casing member 36 . The second carbon fiber sheet has a size of, for example, 5 mm×10 mm. The thickness of the chopped material is, for example, 0.1 mm. In the second carbon fiber sheet, the plurality of second carbon fibers 46 are preferably arranged in any one of the first direction and the direction intersecting the first direction, respectively. The plurality of second carbon fibers 46 may be stacked in the thickness direction of the first casing member 48 and the second casing member 50 . Although FIG. 11 schematically shows the filling member 38 in which the second carbon fibers 46 are stacked in three layers, the filling member 38 may have the second carbon fibers 46 stacked in four or more layers. The filling member 38 preferably contains a resin material. The resin material contains epoxy resin, for example. The resin material is the base material of the second carbon fiber sheet. The filling member 38 is formed by hot press forming a plurality of chopped materials.

The second fiber length of at least one second carbon fiber 46 is 5 mm or more and 24 mm or less. The second fiber length of the longest second carbon fiber 46 among the plurality of second carbon fibers 46 is preferably 5 mm or more and 24 mm or less. The plurality of second carbon fibers 46 may include second carbon fibers 46 having a second fiber length of less than 5 mm. The fiber diameter of the second carbon fibers 46 is, for example, 7 μm. In the filling member 38, the extending direction of the plurality of second carbon fibers 46 differs depending on the arrangement direction of the second carbon fiber sheets of the material.

As shown in FIGS. 5 and 6 , the filling member 38 has the second arrangement portion 54 , and the foam member 40 is preferably arranged in the second arrangement portion 54 of the filling member 38 . The filling member 38 is formed in a ring shape, for example. The filling member 38 is arranged on the annular portion 48C of the first casing member 48 and the annular portion 50C of the second casing member 50 . The foamed member 40 includes, for example, at least one of an imide-based resin foam and an acrylic resin foam.

As shown in FIG. 8, the filling member 38 and the foaming member 40 are arrange|positioned between the 1st case member 48 and the 2nd case member 50 in the thickness direction of the sprocket 30 for manual driving vehicles. The first arrangement portion 42 is surrounded by the inner surface 48B of the first housing member 48 and the inner surface 50B of the second housing member 50 . The second arrangement portion 54 includes at least a part of the concave portion 38A of the filling member 38 . The second arrangement portion 54 is a portion separated from the second housing member 50 by the recessed portion 38A of the filling member 38 . The entire second arrangement portion 54 may be arranged inside the filling member 38 . As shown in FIG. 5 , it is preferable that the filling member 38 has a plurality of concavo-convex shapes in a portion corresponding to the second arrangement portion 54 . The foam member 40 is stably supported by the filling member 38 by the plural concavo-convex shapes.

As shown in FIGS. 1 and 8 , the sprocket 30 for a human-powered vehicle is preferably provided with a sprocket ring member 56 . As shown in FIG. 7 , the sprocket ring member 56 includes an annular base portion 58 and a plurality of sprocket teeth 34 . The plurality of sprocket teeth 34 extend from the annular base portion 58 toward the radially outer side X1 of the relative rotation center axis 30A of the sprocket 30 for a human-powered vehicle. The sprocket ring member 56 preferably includes at least one of iron, aluminum alloy, and titanium alloy.

As shown in FIG. 3 , FIG. 4 , FIG. 7 , and FIG. 8 , the plurality of sprocket teeth 34 are located on the radially outer side X1 rather than the housing member 36 . The annular base portion 58 overlaps the housing member 36 at least in part in the radial direction X. As shown in FIG. The inner peripheral portion of the annular base portion 58 is disposed between the first casing member 48 and the second casing member 50 . The annular base portion 58 of the sprocket ring member 56 preferably has at least one hole portion 58A in which the filling member 38 is disposed. At least one hole portion 58A preferably includes a plurality of hole portions 58A. The plurality of hole portions 58A are arranged between the first casing member 48 and the second casing member 50 . The plurality of hole portions 58A are arranged at intervals in the circumferential direction of the annular base portion 58 . The number of the plural holes 58A is smaller than the number of the plural sprocket teeth 34 , for example. The number of the plurality of holes 58A may be the same as the number of the plurality of sprocket teeth 34 , or more than the number of the plurality of sprocket teeth 34 .

As shown in FIG. 12, the plurality of sprocket teeth 34 preferably include: at least one first tooth 60 having a first chain engagement width W1 and at least one second tooth having a second chain engagement width W2 62. The first chain engagement width W1 and the second chain engagement width W2 are widths by which the sprocket 30 for a human-powered vehicle extends in the axial direction Y relative to the rotation center axis 30A. The first chain engagement width W1 is larger than the second chain engagement width W2.

The first chain engagement width W1 is smaller than the outer link space S1 and larger than the inner link space S2. The second chain engagement width W2 is smaller than the inner link space S2. The outer link space S1 is defined between a pair of outer links 72 of the human-driven vehicle chain 70 that face each other. The inner link space S2 is defined between a pair of inner links 74 of the chain 70 for a human-driven vehicle that face each other.

The first tooth 60 preferably has at least one of a chamfered portion 64 and a recessed portion 66 . At least one of the chamfered portion 64 and the recessed portion 66 can suppress excessive collision between the human-powered vehicle chain 70 and the inner link piece 74 .

The radial height of the first teeth 60 relative to the rotation center axis 20A is preferably larger than the radial height of the second teeth 62 . The first chain engagement width W1 of the first teeth 60 is preferably 80% or more of the outer link space S1. The second chain engagement width W2 of the second teeth 62 is preferably 80% or more of the inner chain piece space S2.

The sprocket ring member 56 is secured to the filling member 38 by a heating and pressing process. Preferably, part of the second carbon fiber sheet melted by the heating and pressing process of the filling member 38 is moved to the inside of the hole portion 58A of the annular base portion 58, and the sprocket ring is hardened by cooling. The member 56 is fixed to the filling member 38 .

An example of the manufacturing method of the sprocket 30 for a human-powered vehicle is demonstrated with reference to FIG. 13. FIG. The manufacturing method of the sprocket 30 for a human-driven vehicle includes a first process, a second process, a third process, a fourth process, a fifth process, a sixth process, and a seventh process.

The first process shown in step S11 is a process including forming the first casing member 48 and the second casing member 50 from a first carbon material, and forming the sprocket ring member 56 from a metal material. For example, the first casing member 48 is formed by pressing and heating in a state in which at least one first carbon fiber sheet including the first carbon material is disposed in the mold of the first casing member 48 . For example, the second casing member 50 is formed by applying pressure and heating in a state where at least one first carbon fiber sheet including the first carbon material is disposed in the mold of the second casing member 50 . For example, the sprocket ring member 56 is formed by at least one of forging, casting, and cutting a metal material.

The second process shown in step S12 includes: arranging the first housing member 48 formed by the first process on the first mold, and arranging the second housing member 50 formed by the first process on the second Mold manufacturing process.

The third process shown in step S13 includes a process of disposing the chopped material of the second carbon material on the first mold. In the third process, the chopped material of the second carbon material is arranged on the first housing member 48 of the first mold in the second process. For example, a plurality of chopped materials are arranged in a stacked manner on the entire first mold. It is preferable to form the second arrangement portion 54 without disposing the chopped material at a portion corresponding to the second arrangement portion 54 .

The fourth process shown in step S14 includes a process of disposing the material of the foamed member 40 and the sprocket ring member 56 formed by the first process on the first mold. In the fourth process, the material of the foamed member 40 is disposed on the chopped material of the second carbon material by the third process. The material of the foam member 40 is arranged in the portion where the second arrangement portion 54 is formed. In the fourth process, the chopped material of the second carbon material may be further superimposed on the material of the foamed member 40 . In the fourth process, the sprocket ring member 56 is disposed on the chopped material of the second carbon material by the third process. In the fourth process, the chopped material of the second carbon material may be further overlapped on the sprocket ring member 56 . In the fourth process, it is preferable to arrange the nut 32B at the portion corresponding to the crank arm mounting portion 32 .

The fifth process shown in step S15 includes a process of combining the first mold and the second mold. In the fifth process, the first mold and the second mold are combined by bringing one of the first mold and the second mold closer to the other.

The sixth process shown in step S16 includes a heating and pressing process. The heating and pressing process is preferably hot pressing. The hot press forming includes, for example, a process of forming by heating at 140° C. and pressing at 10 MPa for 5 minutes. The chopped material melted in the sixth process is introduced into the hole portion 58A of the annular base portion 58 of the sprocket ring member 56 . In the sixth process, the foamed member 40 is formed by the air bubbles generated in the material of the foamed member 40 .

The seventh process shown in step S17 includes a process of removing the first mold and the second mold. The seventh process is preferably performed after the sixth process and after the sprocket 30 for a human-powered vehicle has been sufficiently cooled. By the seventh process, the sprocket 30 for a human-powered vehicle is formed, and the sprocket 30 for a human-driven vehicle includes the first casing member 48 , the second casing member 50 , the filling member 38 , the foam member 40 , and the sprocket teeth. Ring member 56 .

<Second Embodiment> A crank assembly 10A for a human-powered vehicle according to the second embodiment will be described with reference to FIGS. 14 to 20 . The same reference numerals as those in the first embodiment are assigned to the same structures as those in the first embodiment, and overlapping descriptions are omitted.

As shown in FIGS. 14 and 15, the crank assembly 10A for a human-powered vehicle according to the second embodiment includes a first crank arm 16A, a second crank arm 16B, a crank shaft 20, and a sprocket for a human-powered vehicle. 30. The crank assembly 10A for a human-powered vehicle is constituted by an assembly in which the second crank arm 16B is detachably attached to the first crank arm 16A and the crank shaft 20 . The crank assembly 10A for a human-powered vehicle is, for example, a two-piece crank. The crankshaft 20 of this embodiment is a hollow member. The crankshaft 20 includes a first end portion 20X and a second end portion 20Y in the axial direction of the rotation center axis 20A. The first crank arm 16A is attached to the first end portion 20X, and the second crank arm 16B is attached to the second end portion 20Y. In the present embodiment, the first crank arm 16A and the crank shaft 20 are attached to each other in a press-fitted state.

As shown in FIGS. 15 and 16 , the first crank arm 16A includes a base member 100 , a cover member 102 , and a third case member 104 . The third case member 104 covers the outside of the base member 100 in the left-right direction. It is preferable to form a space T between the base member 100 and the third case member 104 .

As shown in FIG. 15 , the base member 100 has a first crankshaft mounting portion 106, and the first crankshaft mounting portion 106 engages with the crankshaft 20 and can transmit torque to each other through splines or the like. The base member 100 is preferably attached to the crankshaft 20 in a detachable manner. For example, the base member 100 is formed as a separate body from the crankshaft 20 , and is attached to the first crankshaft attachment portion 106 by press-fitting the crankshaft 20 . Preferably, the base member 100 includes a metal material. The metal material preferably includes an aluminum alloy.

As shown in FIGS. 15 to 19 , the cover member 102 is arranged to cover the opening of the crankshaft 20 in a state where the crankshaft 20 is engaged with the first crankshaft mounting portion 106 . The cover member 102 preferably includes a first portion 102A and a second portion 102B. The first portion 102A is formed in, for example, a disk shape. The outer diameter of the first portion 102A is larger than the inner diameter of the opening of the first end portion 20X of the crankshaft 20 . Preferably, the outer diameter of the first portion 102A is substantially equal to the outer diameter of the first end portion 20X. The second portion 102B is formed in, for example, a disk shape. The second portion 102B is continuous with the first portion 102A in the axial direction of the crankshaft 20 . The second portion 102B is substantially equal to or slightly larger than the inner diameter of the first end portion 20X of the crankshaft 20 . The cover member 102 includes a protruding portion 102C that protrudes from the first portion 102A and the second portion 102B toward the radially outer side X1 of the rotation center axis 20A of the crankshaft 20 . The cross section of the protrusion 102C orthogonal to the protruding direction thereof is formed in a U-shape. The U-shape of the protrusion 102C is opened on the crankshaft 20 side. The cover member 102 preferably contains a resin material. The resin material preferably includes a synthetic resin material. The cover member 102 preferably has flexibility.

In the present embodiment, the U-shaped bottom surface of the protruding portion 102C is the same surface as the surface on the first crank arm 16A side of the first portion 102A. The end of the opening on the crankshaft 20 side of the protruding portion 102C is located closer to the first portion 102A than the end of the second portion 102B on the crankshaft 20 side. At least a part of the second portion 102B of the cover member 102 is fitted into the inner peripheral portion of the opening of the first end portion 20X of the crankshaft 20 . Preferably, the protruding portion 102C includes the guiding portion 102D. The guide portion 102D includes a side surface along a direction orthogonal to the bottom surface of the U-shape among the protruding portions 102C. The base member 100 is provided with a recessed portion 112 into which at least a part of the guide portion 102D is fitted. The concave portion 112 is concave in a U-shape when viewed from the radially outer side X1 of the relative rotation center axis 20A of the crankshaft 20 . The concave portion 112 has a tapered shape tapered toward the bottom. The communication portion 110 is located at the engaging portion of the cover member 102 and the recessed portion 112 . The opening part of the 1st end part 20X of the crankshaft 20 is provided with the notch part 20Z. The crankshaft 20 and the base member 100 are attached so that the cutout portion 20Z and the recessed portion 112 at least partially overlap. In a state in which the crankshaft 20 and the base member 100 are mounted, the shape of the notch portion 20Z when viewed from the radially outer side X1 is preferably substantially the same as the shape of the recessed portion 112 . When the cover member 102 is attached to the first end portion 20X of the crankshaft 20 and the base member 100 , the guide portion 102D is guided toward the bottom of the recessed portion 112 along the tapered shape of the recessed portion 112 and the cutout portion 20Z. Therefore, when the cover member 102 is attached to the crankshaft 20 and the base member 100, the position of the cover member 102 with respect to the crankshaft 20 and the base member 100 is not easily deviated from the desired position.

As shown in FIGS. 14 and 16 , the third case member 104 is attached to the base member 100 and the cover member 102 via the adhesive 108 . FIG. 16 shows a hypothetical state in which the adhesive 108 disposed between the third case member 104 and the base member 100 and the cover member 102 is hardened. The adhesive 108 is applied to the portion of the base member 100 where the third housing member 104 is fitted, and to the portion of the base member 100 where the second portion 102B of the cover member 102 is fitted into the base member 100 and the crankshaft 20 . The outer part of the first part 102A. The third housing member 104 is preferably made of a metal material. Preferably, the metal material includes an aluminum alloy material. The adhesive 108 preferably contains a resin material. The third casing member 104 may be formed of a non-metallic material such as carbon-reinforced fiber.

As shown in FIGS. 18 and 19 , the crank assembly 10A for a human-powered vehicle has a communication portion 110 . The communication portion 110 communicates the space T of the first crank arm 16A with the inner space 114 of the crankshaft 20 . The communication portion 110 is formed between the cover member 102 , the notch portion 20Z of the opening of the first end portion 20X of the crankshaft 20 , and the base member 100 .

As shown in Fig. 15, the second crank arm 16B is a hollow member. The second crank arm 16B is preferably made of a metal material. The metal material preferably includes an aluminum alloy. The second crank arm 16B is formed by, for example, forging. It is preferable that the inner space of the second crank arm 16B does not communicate with the outer space.

As shown in FIGS. 15 and 20 , the second crank arm 16B is attached to the second end portion 20Y of the crank shaft 20 . The seal member 116 is attached to the second end portion 20Y of the crankshaft 20 . The sealing member 116 contains a resin material. The resin material preferably includes a synthetic resin material. The sealing member 116 preferably has flexibility. The sealing member 116 is arranged inside the opening of the second end portion 20Y. The sealing member 116 preferably closes the opening of the second end portion 20Y. Since the sealing member 116 is in close contact with the inner peripheral portion of the crankshaft 20, it has a high sealing effect. Therefore, the sealing member 116 can prevent foreign matter such as water and mud from entering the inner space 114 of the crankshaft 20 .

The second crank arm 16B is attached to the second end portion 20Y of the crank shaft 20 by the bolt member 118 . The bolt member 118 is arranged on the end surface side of the second end portion 20Y of the crankshaft 20 relative to the seal member 116 in the axial direction of the crankshaft 20 . The bolt member 118 preferably includes a metallic material. The metal material preferably includes an aluminum alloy. For example, the bolt member 118 is an accelerator bolt. In a state where the second end 20Y of the crankshaft 20 is inserted into the hole 16C provided in the second crank arm 16B, the bolt member 118 is screwed into a female provided on the inner peripheral portion of the second end 20Y of the crankshaft 20 . Threaded portion 20W. The flange portion 120 of the bolt member 118 restrains the second crank arm 16B from moving outward in the axial direction relative to the crankshaft 20 .

The manufacturing method of the assembly of the first crank arm 16A and the crankshaft 20 includes a first process, a second process, a third process, and a fourth process.

The first process includes a process of attaching the base member 100 to the crankshaft 20 . In the first process, the crankshaft 20 is attached to the first crankshaft attachment portion 106 .

The second process includes a process of attaching the cover member 102 to the first end portion 20X of the crankshaft 20 of the base member 100 and the base member 100 in the first process. In the second process, the second portion 102B of the cover member 102 is inserted into the inner peripheral portion of the first end portion 20X of the crankshaft 20 so that the guide portion 102D enters the notch portion 20Z of the first end portion 20X and the base member Recess 112 of 100 . The communication portion 110 is formed in the second process.

The third process includes: applying an adhesive 108 on each of the base member 100 and the cover member 102 facing the third housing member 104 , and attaching the base member 100 and the cover member 102 , The process of bonding with the third housing member 104 .

In the third process, the air in the space T of the first crank arm 16A moves to the inner space 114 of the crankshaft 20 through the communication portion 110 . The air that has moved into the inner space 114 of the crankshaft 20 is released to the outside space from the opening of the second end portion 20Y of the crankshaft 20 . By releasing the air to the outside, the space T of the first crank arm 16A does not have a positive pressure. Therefore, the base member 100, the cover member 102, and the third case member 104 can be firmly assembled.

The fourth process includes a process of attaching the sealing member 116 to the second end portion 20Y of the crankshaft 20 . By attaching the sealing member 116, the inner space of the crankshaft 20 and the space T of the first crank arm 16A are closed.

In the third process, the air in the space T of the first crank arm 16A can be moved through the communication portion 110 even if the first crank arm 16A is not provided with a hole portion or the like for removing the air in the space T of the first crank arm 16A to the space inside the crankshaft 20 .

In the case of applying the adhesive 108 in the third process, the movement of the adhesive 108 toward the communication portion 110 is suppressed by the protrusion 102C. Therefore, the adhesive 108 can be suppressed from closing the communication portion 110 .

The first crank arm 16A, the crankshaft 20 , and the cover member 102 of the second embodiment can also be applied to a crank assembly for a human-powered vehicle provided with a sprocket for a human-driven vehicle different from the sprocket 30 for a human-driven vehicle.

(Variation) The description of the embodiment is an example of the form that the sprocket for a human-powered vehicle of the present invention can take, and is not intended to limit the form. The sprocket for a human-powered vehicle of the present invention can take, for example, a combination of a modification of the above-described embodiment shown below and a combination of at least two modifications that do not contradict each other. In the following modifications, the same reference numerals as those in the embodiment are attached to the parts common to the embodiment, and the description thereof will be omitted.

The first teeth 60 may be omitted from the plurality of sprocket teeth 34 . In this case, it is preferable that all the sprocket teeth 34 have a chain engagement width corresponding to the second chain engagement width W2 of the second teeth 62 .

As shown in FIG. 21 , the sprocket 30 for a human-powered vehicle may be attached to the crank arm member 12 via a lock ring 68 . The sprocket 30 for a human-powered vehicle shown in FIG. 21 is splined to the crank arm member 12 . The lock ring 68 is attached to the crank arm member 12 so as to sandwich the sprocket 30 for a human-powered vehicle.

The shell member 36 may include only one first carbon fiber 44 . In this case, for example, the first carbon fibers 44 are bent and arranged in one of the first casing member 48 and the second casing member 50 .

The filling member 38 may include only one second carbon fiber 46 . In this case, for example, the filling member 38 may be formed of a second carbon fiber sheet having a shape corresponding to the shape of the filling member 38 and including at least one second carbon fiber 46 .

The first carbon fiber length of the at least one first carbon fiber 44 may be smaller than the second carbon fiber length of the at least one second carbon fiber 46 .

The density of the shell member 36 and the density of the filling member 38 may be smaller or larger or the same. The density of the shell member 36 and the density of the filling member 38 depend on the ratio of carbon fibers per unit area and the material of the resin member, respectively. By making the density of the filling member 38 smaller than the density of the casing member 36, the weight of the filling member 38 can be reduced. When the volume of the filling member 38 is smaller than the volume of the casing member 36 , by making the density of the filling member 38 smaller than that of the casing member 36 , the sprocket 30 for a human-powered vehicle can be reduced in weight.

The annular base portion 58 of the sprocket ring member 56 may not have the hole portion 58A. In this case, the sprocket ring member 56 may have a concavo-convex shape in a portion that is in contact with the filling member 38 . In this case, the sprocket ring member 56 may be fixed to the casing member 36 or the filling member 38 by bolts, rivets, or the like after the seventh process.

The filling member 38 of the sprocket 30 for a human-driven vehicle may be changed to a manufacturing method including an injection molding process instead of a manufacturing method including a heating and pressing process. In this case, the second fiber length of the filling member 38 is selected to a size suitable for injection molding.

In the 4th process of the manufacturing method of the sprocket 30 for a manual drive vehicle, you may replace with the material of the foamed member 40, and may arrange|position the preliminarily formed foamed member 40 in a 1st metal mold|die.

The sprocket 30 for a human-driven vehicle may be a rear sprocket. When the sprocket 30 for a human-powered vehicle is a rear sprocket, the crank arm mounting portion 32 is omitted, and instead, a plurality of splines for engaging with the rear-hub assembly for a human-powered vehicle so as to transmit torque are formed in the rear chain The radial inner peripheral surface of the rear sprocket relative to the rotational center axis of the wheel.

The expression "at least one" used in this specification means "one or more" of the required options. As an example, the expression "at least one" used in this specification, if the number of options is two, means "only one option" or "both two options". As another example, the expression "at least one" used in this specification means "only one option" or "a combination of two or more arbitrary options" if the number of options is three or more.

30: Sprockets for human-driven vehicles 30A: Rotation center axis 34: Sprocket 36: Shell components 38: Filling components 40: Foam components 42: Part 1 Configuration 44: 1st carbon fiber 46: 2nd carbon fiber 54: Part 2 Configuration 56: Sprocket ring member 58: Ring-shaped base 58A: Hole 60: 1st tooth 62: 2nd tooth 70: Chains for human-driven vehicles 72: Outer chain piece 74: inner chain piece

[FIG. 1] It is a front view of the crank assembly for a human-powered vehicle provided with the sprocket for a human-driven vehicle of the first embodiment. [Fig. 2] It is a perspective view of the sprocket for a human-powered vehicle of Fig. 1. [Fig. [Fig. 3] It is a front view of the sprocket for a human-powered vehicle shown in Fig. 1. [Fig. [Fig. 4] It is a rear view of the sprocket for a human-powered vehicle shown in Fig. 1. [Fig. [FIG. 5] It is a perspective view of the 1st casing member and the filling member of the sprocket for a human-powered vehicle of FIG. 1. FIG. [FIG. 6] It is a perspective view of the 1st shell member, the filling member, and the foam member of the sprocket for a human-powered vehicle of FIG. 1. [FIG. [FIG. 7] It is a front view of the sprocket ring member of the sprocket for a human-powered vehicle of FIG. 1. [FIG. [FIG. 8] It is a sectional view taken along the line D8-D8 in FIG. 3. FIG. [FIG. 9] It is a schematic diagram which shows typically the part of the 1st case member of the cross section of FIG. 8. FIG. [FIG. 10] It is a schematic diagram which shows typically the part of the 2nd case member of the cross section of FIG. 8. FIG. [ Fig. 11 ] A schematic diagram schematically showing a part of the filling member in the cross section of Fig. 8 . [Fig. 12] It is a plan view showing the sprocket for a human-powered vehicle and the chain for a human-driven vehicle of Fig. 1. [Fig. [Fig. 13] is a flow chart showing the manufacturing process of the sprocket for a human-powered vehicle of Fig. 1. [Fig. [FIG. 14] It is a perspective view of a crank assembly for a human-powered vehicle including the sprocket for a human-powered vehicle according to the second embodiment. [Fig. 15] It is a cross-sectional view of the crank assembly for a human-powered vehicle shown in Fig. 4. [Fig. [Fig. 16] It is an exploded perspective view of the first crank arm and the crank shaft in Fig. 4. [Fig. [Fig. 17] It is a perspective view of the cover member of Fig. 16. [Fig. [FIG. 18] It is a sectional view taken along the line D18-D18 in FIG. 15. FIG. [FIG. 19] It is an enlarged partial cross-sectional view of the cover member and its periphery shown in FIG. 15. [FIG. 19] FIG. [FIG. 20] It is an enlarged partial cross-sectional view of the sealing member of FIG. 15 and its periphery. [ Fig. 21 ] It is a cross-sectional view of a crank assembly for a human-powered vehicle including a sprocket for a human-driven vehicle according to a modification of the embodiment.

30: Sprockets for human-driven vehicles

34: Sprocket

36: Shell components

38: Filling components

38A: Recess

40: Foam components

42: Part 1 Configuration

48: 1st housing member

48A: External face

48B: Inside

48C: Torus

50: Second housing member

50A: External face

50B: Inside

50C: Ring part

54: Part 2 Configuration

58: Ring-shaped base

58A: Hole

R: Circumferential direction

X: Radial

X1: Radial outer side

X2: radial inner side

Claims (12)

A sprocket for a human-driven vehicle, comprising: Plural sprockets made of metal, a shell member made of a first carbon material having a first arrangement portion and including at least one first carbon fiber having a first fiber length, a filling member made of a second carbon material disposed in the first disposition portion of the outer shell member and containing at least one second carbon fiber having a second fiber length, And the foam member disposed in the above-mentioned first disposition part of the above-mentioned shell member; The above-mentioned first fiber length is different from the above-mentioned second fiber length. The sprocket for a human-powered vehicle according to claim 1, wherein the first fiber length is greater than the second fiber length. The sprocket for a human-powered vehicle according to claim 1 or 2, wherein the at least one first carbon fiber includes a plurality of first carbon fibers, The at least one second carbon fiber includes a plurality of second carbon fibers. The sprocket for a human-powered vehicle according to claim 1 or 2, wherein the filling member has a second arrangement portion, The said foam member is arrange|positioned in the said 2nd arrangement|positioning part of the said filling member. The sprocket for a human-driven vehicle according to claim 1 or 2, wherein a sprocket ring member is provided, The sprocket ring member includes an annular base portion, and the plurality of sprocket teeth extending from the base portion toward the radially outer side of the relative rotation center axis of the sprocket for a human-powered vehicle. The sprocket for a human-powered vehicle according to claim 5, wherein the sprocket ring member is fixed to the filling member by a heating and pressing process. The sprocket for a human-powered vehicle according to claim 5, wherein the base portion of the sprocket ring member has at least one hole for arranging the filling member. The sprocket for a human-powered vehicle according to claim 7, wherein the at least one hole portion of the base portion includes a plurality of hole portions. The sprocket for a human-powered vehicle according to claim 1 or 2, wherein the first fiber length of the at least one first carbon fiber is 25 mm or more and 510 mm or less. The sprocket for a human-powered vehicle according to claim 1 or 2, wherein the second fiber length of the at least one second carbon fiber is 5 mm or more and 24 mm or less. The sprocket for a human-powered vehicle according to claim 1 or 2, wherein the plurality of sprocket teeth include at least one first tooth having a first chain engagement width, and at least one second chain having a second chain engagement width. tooth; The first chain engagement width and the second chain engagement width are widths extending in the axial direction with respect to the rotation center axis of the sprocket for a human-powered vehicle, The said 1st chain engagement width is larger than the said 2nd chain engagement width. The sprocket for a human-powered vehicle according to claim 11, wherein the first chain engagement width is smaller than the outer link space defined between the pair of opposite outer links of the human-driven vehicle chain, and greater than The inner chain piece space defined between a pair of inner chain pieces facing each other of the above-mentioned human-powered vehicle chain, The said second chain engagement width is smaller than the said inner link piece space.

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