JP2015227152A - Component for bicycle, shaft member for bicycle, rear sprocket assembly for bicycle, and lever member for bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a component for a bicycle which simultaneously achieves improvement of joint strength, weight reduction, and improvement of the appearance.SOLUTION: A crank assembly includes: a right crank; a left crank; and a crank shaft. The right crank includes: a first crank arm member 15 (one example of a first member); and a second crank arm member 16 (one example of a second member) which is disposed facing the first crank arm member 15. An internal space S1 is formed between the first crank arm member 15 and the second crank arm member 16. In the state, the first crank arm member 15 and the second crank arm member 16 are joined by diffusion welding.

Description

  The present invention relates to a bicycle component, a bicycle shaft member, a bicycle rear sprocket assembly, and a bicycle lever member.

  In a conventional bicycle part, a plurality of members are joined together by bonding, brazing, laser welding or the like, and configured as one bicycle part. If it demonstrates using a crank arm as an example, the conventional crank arm will have a crank body and a lid member joined to a crank body by adhesion or welding (for example, patent documents 1 and patent documents 2). reference).

JP 2008-001287 A US Pat. No. 5,988,016

  In a conventional bicycle component, for example, a crank arm, when the lid member is joined to the crank body by an adhesive, it is necessary to set a sufficient joining area to ensure a necessary joining strength. Further, in this case, the bonding line of the bonded portion may impair the appearance of the component. Further, in the crank arm, when the lid member is joined to the crank body by welding, there is a possibility that the weld mark at the joined portion may damage the appearance of the part. Furthermore, in joining by bonding or welding, it is necessary to add an adhesive or a filler material, which may increase the weight of the crank arm.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a bicycle component that can simultaneously realize improvement in joint strength, weight reduction, and improvement in appearance. is there.

  A bicycle component according to the present invention includes a first member and a second member disposed to face the first member. An internal space is formed between the first member and the second member. The first member and the second member are joined by diffusion joining.

  In this bicycle part, since the first member and the second member are joined by diffusion joining, the joining strength between the first member and the second member can be improved as compared with joining by adhesion or welding. . Further, even if an internal space is formed between the first member and the second member and the bonding area is reduced, the bonding strength between the first member and the second member can be sufficiently secured by diffusion bonding. it can. That is, the bicycle component can be reduced in weight. Furthermore, in diffusion bonding, since no adhesive sticking out or welding marks are generated, the appearance of bicycle parts can be improved. That is, with this bicycle component, it is possible to simultaneously improve the bonding strength, reduce the weight, and improve the appearance.

  The bicycle component according to the present invention may be configured as follows. One of the first member and the second member is made of the first material. One of the first member and the second member is made of a second material different from the first material.

  In this case, even if the first member and the second member are made of different materials, the first member and the second member can be reliably bonded by diffusion bonding.

  The bicycle component according to the present invention may be configured as follows. The first material is an aluminum alloy. The second material is an iron alloy.

  In this case, since the first material is an aluminum alloy, the bicycle component can be reduced in weight. Moreover, since the second material is an iron alloy, the rigidity of the bicycle part can be ensured. That is, by joining the first member and the second member by diffusion bonding, it is possible to reduce the weight of the bicycle component while ensuring the rigidity of the bicycle component.

  The bicycle component according to the present invention may be configured as follows. The first member and the second member are made of the same kind of metal material.

  In this case, sufficient bonding strength can be ensured, and the bonding line between the first member and the second member can be made less noticeable. That is, the appearance of the bicycle component can be further improved.

  The bicycle component according to the present invention may be configured as follows. The first member has a first base portion, a first side surface portion, and a second side surface portion. The first side surface portion extends from one end portion of the first base body portion in the thickness direction of the first base body portion. The second side surface portion extends from the other end portion of the first base body portion in the thickness direction of the first base body portion and faces the first side surface portion. The second member is disposed to face the first base portion. The first side surface portion and the second side surface portion are joined to the second member by diffusion bonding.

  In this case, an internal space is formed by the first base portion of the first member, the first side surface portion of the first member, the second side surface portion of the first member, and the second member. In this state, the first side surface portion and the second side surface portion are joined to the second member by diffusion bonding. That is, by forming the internal space, even if the bonding area between the first side surface portion and the second side surface portion and the second member is reduced, the first member and the second member are securely connected by diffusion bonding. Can be joined.

  The bicycle component according to the present invention may be configured as follows. The second member is plate-shaped.

  In this case, the first member and the second member can be reliably bonded even if the bonding area between the first side surface portion and the second side surface portion of the first member and the plate-shaped second member is small.

  The bicycle component according to the present invention may be configured as follows. The second member has a second base part, a third side part, and a fourth side part. The third side surface portion extends from the one end portion of the second base portion in the thickness direction of the second base portion. The fourth side surface portion extends from the other end portion of the second base body portion in the thickness direction of the second base body portion, and faces the third side surface portion. The second base portion is disposed to face the first base portion. One of the first side surface portion and the second side surface portion and one of the third side surface portion and the fourth side surface portion are joined by diffusion bonding. Either the first side surface portion or the second side surface portion and the other side of the third side surface portion or the fourth side surface portion are joined by diffusion bonding.

  In this case, the first base part of the first member, the first side part of the first member, the second side part of the first member, the second base part of the second member, the third side part of the second member, and the first An internal space is formed by the fourth side surface portion of the two members. In this state, the first member and the second member are diffusion-bonded at the side portions. That is, by forming the internal space, the first member and the second member can be reliably bonded by diffusion bonding even if the bonding area between the side surface portions is reduced.

  The bicycle component according to the present invention may be configured as follows. A crank arm is constituted by the first member and the second member.

  In this case, the crank arm is constituted by the first member and the second member. That is, by diffusion-bonding the first member and the second member, as described above, it is possible to improve the joint strength, the weight, and the appearance of the crank arm.

  The bicycle component according to the present invention may be configured as follows. A front sprocket assembly is constituted by the first member and the second member.

  In this case, the front sprocket assembly is constituted by the first member and the second member. That is, by diffusion bonding the first member and the second member, in the front sprocket assembly, as described above, it is possible to improve the bonding strength, reduce the weight, and improve the appearance.

  A bicycle shaft member according to the present invention includes a hollow first shaft member and a second shaft member disposed inside the first shaft member. The first shaft member and the second shaft member are joined by diffusion joining.

  In the bicycle shaft member, the first shaft member and the second shaft member are joined by diffusion bonding in a state where the second shaft member is disposed inside the hollow first shaft member. Thereby, compared with the joining by adhesion | attachment or welding, the joining strength of a 1st member and a 2nd member can be improved. Moreover, even if the bonding area between the first member and the second member is small, the bonding strength between the first member and the second member can be sufficiently ensured by diffusion bonding. That is, the bicycle shaft member can be reduced in weight. Furthermore, in the diffusion bonding, no sticking out of the adhesive or welding marks occurs, so that the appearance of the bicycle shaft member can be improved. That is, with this bicycle shaft member, it is possible to simultaneously improve the bonding strength, reduce the weight, and improve the appearance.

  The bicycle shaft member according to the present invention may be configured as follows. One of the first shaft member and the second shaft member is made of the first material. One of the first shaft member and the second shaft member is made of a second material different from the first material.

  In this case, even if the first member and the second member are made of different materials, the first member and the second member can be reliably bonded by diffusion bonding.

  The bicycle shaft member according to the present invention may be configured as follows. The first material is an aluminum alloy. The second material is an iron alloy.

  In this case, since the first material is an aluminum alloy, the bicycle shaft member can be reduced in weight. Moreover, since the second material is an iron alloy, the rigidity of the bicycle shaft member can be ensured. That is, by joining the first member and the second member by diffusion bonding, it is possible to reduce the weight of the bicycle shaft member while ensuring the rigidity of the bicycle shaft member.

  The bicycle shaft member according to the present invention may be configured as follows. The second shaft member is a hollow member. A crankshaft is constituted by the first shaft member and the second shaft member.

  In this case, the crankshaft is constituted by the first member and the second member. That is, by diffusion bonding the first member and the second member, as described above, in the crankshaft, the joint strength is improved, the weight of the second member is hollow in addition to the first member, and An improvement in appearance can be realized.

  The bicycle shaft member according to the present invention may be configured as follows. The second shaft member is a hollow member. A hub shaft is constituted by the first shaft member and the second shaft member.

  In this case, the hub shaft is constituted by the first member and the second member. That is, by diffusion-bonding the first member and the second member, as described above, in the hub axle, the joint strength is improved, the weight of the second member is hollow in addition to the first member, and An improvement in appearance can be realized.

  A bicycle rear sprocket assembly according to the present invention includes a sprocket body and a sprocket support that supports the sprocket body. The sprocket body and the sprocket support are joined by diffusion bonding.

  In the bicycle rear sprocket assembly, the sprocket body and the sprocket support are joined by diffusion bonding in a state where the sprocket body is supported by the sprocket support. Thereby, compared with the joining by adhesion | attachment or welding, the joining strength of a sprocket main-body part and a sprocket support part can be improved. Moreover, even if the joining area between the sprocket body and the sprocket support is small, the joining strength between the sprocket body and the sprocket support can be sufficiently secured by diffusion joining. Furthermore, when joining the sprocket body and the sprocket support, a fixing member such as a rivet or bolt is not required. Therefore, the bicycle rear sprocket assembly can be reduced in weight. Further, since diffusion bonding does not cause adhesive sticking or welding marks, the appearance of the bicycle rear sprocket assembly can be improved. That is, in this bicycle rear sprocket assembly, it is possible to simultaneously improve the joint strength, reduce the weight, and improve the appearance.

  The bicycle rear sprocket assembly according to the present invention may be configured as follows. One of the sprocket body and the sprocket support is made of the first material. The other of the sprocket body and the sprocket support is made of a second material different from the first material.

  In this case, even if the sprocket main body and the sprocket support are made of different materials, the sprocket main body and the sprocket support can be reliably bonded by diffusion bonding.

  The bicycle rear sprocket assembly according to the present invention may be configured as follows. The first material is an aluminum alloy. The second material is an iron alloy.

  In this case, since the first material is an aluminum alloy, the bicycle rear sprocket assembly can be reduced in weight. Further, since the second material is an iron alloy, the rigidity of the bicycle rear sprocket assembly can be ensured. That is, by joining the bicycle rear sprocket main body portion and the sprocket support portion by diffusion bonding, it is possible to reduce the weight of the rear sprocket assembly while ensuring the rigidity of the bicycle rear sprocket assembly.

  The bicycle lever member according to the present invention includes a first lever portion and a second lever portion disposed to face the first lever portion. The first lever part and the second lever part are joined by diffusion joining.

  In the bicycle lever member, the first lever portion and the second lever portion are joined by diffusion bonding in a state where the second lever portion is disposed to face the first lever portion. Thereby, compared with joining by adhesion | attachment or welding, the joining strength of a 1st lever part and a 2nd lever part can be improved. Further, even if the joining area between the first lever part and the second lever part is small, the joining strength between the first lever part and the second lever part can be sufficiently secured by diffusion joining. That is, the weight of the bicycle lever member can be reduced. Furthermore, in the diffusion bonding, since no sticking out of the adhesive or welding marks occur, the appearance of the bicycle lever member can be improved. That is, with this bicycle lever member, it is possible to simultaneously improve the bonding strength, reduce the weight, and improve the appearance.

  The bicycle lever member according to the present invention may be configured as follows. One of the first lever portion and the second lever body is made of the first material. Either one of the first lever portion and the second lever body is made of a second material different from the first material.

  In this case, even if the first lever portion and the second lever body are made of different materials, the first lever portion and the second lever body can be reliably bonded by diffusion bonding.

  The bicycle lever member according to the present invention may be configured as follows. The first material is an aluminum alloy. The second material is an iron alloy.

  In this case, since the first material is an aluminum alloy, the bicycle lever member can be reduced in weight. Moreover, since the second material is an iron alloy, the rigidity of the bicycle lever member can be ensured. That is, by joining the first lever portion and the second lever portion by diffusion bonding, it is possible to reduce the weight of the bicycle lever member while ensuring the rigidity of the bicycle lever member.

  The bicycle component according to the present invention includes a first member and a second member. The first member is formed by forging. The first member and the second member are joined by diffusion bonding.

  In this bicycle part, since the first member and the second member are joined by diffusion joining, the joining strength between the first member and the second member can be improved compared to joining by adhesion or welding. it can. Moreover, even if the first member is formed by forging, this effect can be obtained. Furthermore, in diffusion bonding, since no adhesive sticking out or welding marks are generated, the appearance of bicycle parts can be improved. That is, with this bicycle component, it is possible to simultaneously improve joint strength and appearance.

  The bicycle component according to the present invention may be configured as follows. The first member and the second member are made of the same material.

  In this case, the first member and the second member are made of the same material, and the first member and the second member can be reliably bonded by diffusion bonding. Furthermore, the joint line between the first member and the second member can be made less noticeable. That is, the appearance of the bicycle component can be further improved.

  The bicycle component according to the present invention may be configured as follows. The first member and the second member include any one of iron, aluminum, and titanium.

  In this case, the first member and the second member are made of the same material, and the first member and the second member contain any one of iron, aluminum, and titanium. The rigidity can be improved and / or the weight can be reduced.

  The bicycle component according to the present invention may be configured as follows. One of the first member and the second member is made of the first material. One of the first member and the second member is made of a second material different from the first material.

  In this case, even if the first member and the second member are made of different materials, the first member and the second member can be reliably bonded by diffusion bonding.

  The bicycle component according to the present invention may be configured as follows. The first material includes any one of iron, aluminum, and titanium. The second material includes any one of iron, aluminum, and titanium.

  In this case, even if the first member and the second member are made of different materials, the first member and the second member contain any one of iron, aluminum, and titanium. It is possible to improve the rigidity of the component and / or reduce the weight.

  The bicycle component according to the present invention may be configured as follows. The second member is formed by a process different from forging.

  In this case, even if the second member is formed by a process different from forging, the first member and the second member can be reliably bonded by diffusion bonding.

  The bicycle component according to the present invention may be configured as follows. The second member is formed by a bending process different from forging.

  In this case, even if the second member is formed by bending, the first member and the second member can be reliably bonded by diffusion bonding. Furthermore, since the second member can be thinned, the weight of the bicycle part can be reduced.

  The bicycle component according to the present invention may be configured as follows. The second member is a plate member and is formed by a process different from forging, for example, a bending process.

  In this case, even if the second member is a plate member, the first member and the second member can be reliably bonded using diffusion bonding by performing the above processing. Furthermore, since it is easier to reduce the thickness of the second member, the weight of the bicycle part can be easily reduced.

  The bicycle component according to the present invention may be configured as follows. The bicycle component further includes a third member molded by forging. The third member is diffusion bonded to at least one of the first member and the second member.

  In this case, even if the bicycle component further includes the third member in addition to the first member and the second member, the joint strength can be improved and the appearance can be improved simultaneously by diffusion bonding. .

  The bicycle component according to the present invention may be configured as follows. The first member has a first shaft mounting portion for mounting the first shaft member.

  In this case, since the first member has the first shaft attachment portion, the first shaft member can be attached to the first member.

  The bicycle component according to the present invention may be configured as follows. The third member has a second shaft mounting portion for mounting the second shaft member.

  In this case, since the third member has the second shaft attaching portion, the third shaft member can be attached to the third member.

  The bicycle component according to the present invention may be configured as follows. The first member, the second member, and the third member constitute a crank arm. A crankshaft can be attached to the first shaft attachment portion. A pedal shaft can be attached to the second shaft attachment portion.

  In this case, even if the crank arm is constituted by the first member, the second member, and the third member, the bonding strength is improved by diffusion bonding the first member, the second member, and the third member. In addition, the appearance can be improved at the same time.

  According to the present invention, in a bicycle part, it is possible to simultaneously improve joint strength, weight reduction, and appearance. The same effect can be realized in the bicycle shaft member, the bicycle rear sprocket assembly, and the bicycle lever member.

1 is a side view of a bicycle according to an embodiment of the present invention. Right crank side view The disassembled perspective view of the 1st crank arm member and 2nd crank arm member in a right crank. Sectional drawing in the center part of a right crank. The perspective view of a left crank. Sectional drawing of the cutting line VV of FIG. Sectional drawing of the cutting line VI-VI of FIG. Sectional drawing of a crank assembly. The side view of a rear sprocket assembly (1st rear sprocket assembly). The fragmentary sectional view of a rear sprocket assembly (1st rear sprocket assembly). The side view and sectional drawing of a front hub assembly. The side view and sectional drawing of a rear hub axis | shaft. The perspective view of a brake lever (the 1). The perspective view of a brake lever (the 2). FIG. 6 is a partial cross-sectional view of a sprocket assembly according to another embodiment of the present invention. The front view of the cover support part of the sprocket assembly by other embodiment of this invention. The disassembled perspective view of the 5th crank arm member and the 6th crank arm member in the right crank by other embodiment of this invention. FIG. 15B is a cross-sectional view taken along section line XVB-XVB in FIG. 15A. The disassembled perspective view of the 5th crank arm member in the right crank by other embodiment of this invention. FIG. 16B is a partially enlarged view of the fifth crank arm member of FIG. 16A as viewed from above.

[Overall configuration of bicycle]
In FIG. 1, a bicycle 101 employing one embodiment of the present invention mainly includes a frame 102, a handle 104, a drive unit 105, front and rear wheels 106 and 107, and front and rear brake devices 108 and 109. Is provided.

  The frame 102 has a front fork 98. The handle 104 is fixed to the front fork 98. The drive unit 105 mainly includes a crank assembly 10 and a rear sprocket assembly 20. The front and rear wheels 106 and 107 are attached to the front fork 98 and the rear portion of the frame 102 via the front hub assembly 30 and the rear hub assembly 40. The front and rear brake devices 108 and 109 are operated by operating the brake lever 110. Since the front and rear brake devices 108 and 109 are the same as the conventional configuration, the description thereof is omitted here.

[Configuration of crank assembly]
As shown in FIGS. 1 to 7, the crank assembly 10 includes a right crank 12, a left crank 13, and a crankshaft 11.

  As shown in FIGS. 2, 3A and 3B, the right crank 12 includes a first crank arm member 15 (an example of a first member) and a second crank arm member 16 (an example of a second member). Have. The first crank arm member 15 and the second crank arm member 16 are disposed to face each other. Further, an internal space S <b> 1 is formed between the first crank arm member 15 and the second crank arm member 16. In this state, the first crank arm member 15 and the second crank arm member 16 are joined by diffusion joining.

  Here, the 1st crank arm member 15 is comprised from metals, such as an iron alloy (an example of 2nd material), for example. The second crank arm member 16 is made of a metal (an example of the first material) such as an aluminum alloy, for example. Instead, the first crank arm member 15 and the second crank arm member 16 may be made of the same kind of metal material such as an aluminum alloy. In this case, the joining line between the first crank arm member 15 and the second crank arm member 16 is further inconspicuous while ensuring sufficient joining strength. That is, the appearance can be further improved.

  Specifically, the first crank arm member 15 includes a first arm portion 25 and a sprocket mounting portion 35.

  The first arm portion 25 includes a first bottom portion 25a (an example of a first base portion), a pair of first edge portions 25b (an example of a first side surface portion and a second side surface portion), and a fixed portion 25c for a pedal shaft. And a first step portion 25d.

  The first bottom portion 25a is a portion extending in the radial direction with respect to the crankshaft 11. The 1st bottom part 25a is arrange | positioned facing the 2nd bottom part of the 2nd arm member mentioned later. A pair of 1st edge part 25b is a part extended in the thickness direction of the 1st bottom part 25a from the outer edge part of the 1st bottom part 25a. The pair of first edge portions 25b are formed integrally with the first bottom portion 25a so as to face each other. The angle formed by the first edge 25b and the first bottom 25a may be any angle.

  The pedal shaft fixing portion 25c is formed on the distal end side of the first bottom portion 25a. The fixed portion 25c for the pedal shaft is integrally formed on the distal end side of the first bottom portion 25a. A pedal mounting hole 25e for mounting a pedal shaft (not shown) is formed in the pedal shaft fixing portion 25c.

  The first step portion 25d is formed on the outer periphery of the pedal shaft fixing portion 25c. Specifically, the first step portion 25d is continuously formed from the first edge portion 25b to the outer peripheral portion of the pedal fixing portion 25c.

  The sprocket mounting portion 35 includes first to fourth sprocket mounting arm portions 35a to 35d, a second stepped portion 35e, and a crankshaft fixing portion 35f.

  Sprocket mounting holes are provided at the tip ends of the first to fourth sprocket mounting arm portions 35a to 35d. A sprocket assembly 50 composed of the first sprocket 31 and the second sprocket 32 is disposed at the tip of the first to fourth sprocket mounting arm portions 35a to 35d. Specifically, the first sprocket 31 and the second sprocket 32 are disposed on both sides of the tip end portions of the first to fourth sprocket mounting arm portions 35a to 35d. In this state, the first sprocket 31 and the second sprocket 32 are fixed to the sprocket mounting portion 35 by the fixing bolt 35g (see FIG. 1).

  Note that the configuration of the sprocket assembly 50 is the same as the conventional configuration, and thus detailed description thereof is omitted here. The first sprocket 31 and the second sprocket 32 may be interpreted as the first sprocket assembly 31 and the second sprocket assembly 32.

  The second step portion 35e is formed integrally with the outer peripheral portion of the first to fourth sprocket mounting arm portions 35a to 35d (excluding the sprocket mounting hole portion). Here, in the first and fourth sprocket mounting arm portions 35a and 35d, the second step portion 35e formed in the first arm portion 25 is continuously formed from the first edge portion 25b. Further, the second step portion 35e is formed on the same plane as the tip portion (contact portion) of the first edge portion 25b.

  The crankshaft fixing portion 35 f has a fixing hole 35 h for fixing one end portion of the crankshaft 11. A spline groove is formed in the crankshaft fixing hole 35h.

  The second crank arm member 16 includes a second arm portion 26 and a cover portion 36 that covers the sprocket mounting portion 35.

  The second arm part 26 has a second bottom part 26a (an example of a second base part) and a second edge part 26b (an example of a third side part and a fourth side part). The second bottom portion 26 a is a portion extending in the radial direction with respect to the crankshaft 11. The second bottom portion 26 a is disposed to face the first bottom portion 25 a of the first arm portion 25. A through hole 26d through which the pedal shaft can pass is formed in the second bottom portion 26a on the distal end side of the second arm portion 26. The through hole 26d is disposed concentrically with the pedal mounting hole 25e of the first crank arm member 15.

  The 2nd edge part 26b is a part extended in the thickness direction of the 2nd bottom part 26a from the outer edge part of the 2nd bottom part 26a. The second edge portion 26b is formed integrally with the second bottom portion 26a. On the distal end side of the second arm portion 26, the second edge portion 26 b abuts on the first step portion 25 d of the first crank arm member 15. In the portion excluding the distal end side of the second arm portion 26, the pair of second edge portions 26b face each other. Each of the pair of second edge portions 26b abuts on the first edge portion 25b.

  The cover part 36 is a part that covers the sprocket attachment part 35. The cover portion 36 is formed integrally with the second arm portion 26 on the proximal end side of the second arm portion 26. Specifically, the cover portion 36 includes a third bottom portion 36a and a third edge portion 36b.

  The third bottom portion 36 b is disposed to face the sprocket mounting portion 35. Specifically, the third bottom portion 36b contacts the first to fourth sprocket mounting arm portions 35a to 35d.

  The third edge portion 36b is a portion extending in the thickness direction of the third bottom portion 36b from the outer edge portion of the third bottom portion 36b. The third edge portion 36b contacts the second stepped portion 35e. That is, substantially no internal space is formed between the cover portion 36 and the sprocket mounting portion 35.

  In the right crank 12 having the above-described configuration, the first crank arm member 15 and the second crank arm member 16 are in contact with each other with the first crank arm member 15 and the second crank arm member 16 in contact with each other as described above. An internal space S1 is formed. In this state, the first crank arm member 15 and the second crank arm member 16 are joined by diffusion bonding a portion T1 (contact portion) where the first crank arm member 15 and the second crank arm member 16 abut. Are joined.

  As shown in FIGS. 4 to 6, the left crank 13 includes a third crank arm member 17 (an example of a second member) and a fourth crank arm member 18 (an example of a first member). The third crank arm member 17 and the fourth crank arm member 18 are disposed to face each other. Further, an internal space S <b> 2 is formed between the third crank arm member 17 and the fourth crank arm member 18. In this state, the third crank arm member 17 and the fourth crank arm member 18 are joined by diffusion joining.

  Here, the third crank arm member 17 is made of a metal such as an iron alloy (an example of the second material), for example. The fourth crank arm member 18 is made of a metal (an example of a first material) such as an aluminum alloy, for example. Instead, the third crank arm member 17 and the fourth crank arm member 18 may be made of the same kind of metal material such as an aluminum alloy. In this case, the joining line between the first crank arm member 15 and the second crank arm member 16 is further inconspicuous while ensuring sufficient joining strength. That is, the appearance can be improved.

  Specifically, the third crank arm member 17 extends in the radial direction with respect to the crankshaft 11. The third crank arm member 17 includes a plate portion 17a, a crankshaft fixing portion 17b, and a pedal shaft fixing portion 17c.

  The crankshaft fixing portion 17b is formed integrally with the plate portion 17a on the base end side of the plate portion 17a. The crankshaft fixing portion 17b includes a first flange portion 17e and a crankshaft fixing hole 17d. The first flange portion 17e is formed on the outer peripheral portion of the crankshaft fixing portion 17b. The first flange portion 17e is formed continuously from the plate portion 17a. The crankshaft fixing hole 17d is for fixing the other end of the crankshaft 11. A spline groove is formed in the crankshaft fixing hole 17d.

  The fixed portion 17c for the pedal shaft is formed integrally with the plate portion 17a on the distal end side of the plate portion 17a. The pedal shaft fixing portion 17c includes a second flange portion 17f and a pedal mounting hole 17g. The second flange portion 17f is formed on the outer peripheral portion of the pedal shaft fixing portion 17c. The second flange portion 17f is formed continuously from the plate portion 17a. The pedal mounting hole 17g is for mounting a pedal shaft.

  The fourth crank arm member 18 extends in the radial direction with respect to the crankshaft 11. The fourth crank arm member 18 is disposed to face the third crank arm member 17. The fourth crank arm member 18 includes a fourth bottom portion 18a (an example of a first base portion) and a fourth edge portion 18b (an example of a first side surface portion and a second side surface portion).

  The fourth bottom portion 18 a is disposed to face the third crank arm member 17. The fourth bottom portion 18a contacts the pedal shaft fixing portion 17c of the third crank arm member 17 on the distal end side. The fourth bottom portion 18a abuts on the crankshaft fixing portion 17b of the third crank arm member 17 on the base end side. The fourth bottom portion 18a is disposed at a central portion with a distance from the plate portion 17a of the third crank arm member 17.

  The 4th edge part 18b is a part extended in the thickness direction of the 4th bottom part 18a from the outer edge part of the 4th bottom part 18a. The fourth edge portion 18b contacts the plate portion 17a of the third crank arm member 17 and the first flange portion 17e and the second flange portion 17f of the third crank arm member 17. Specifically, the fourth edge portion 18b abuts against the first flange portion 17e and the second flange portion 17f of the third crank arm member 17 on the distal end side and the proximal end side. Further, the fourth edge portion 18b is in contact with the outer edge portion of the plate portion 17a of the third crank arm member 17 at the center portion.

  In this way, an internal space S2 is formed at the center of the third crank arm member 17 and the fourth crank arm member 18. The fourth bottom portion 18a is in contact with the pedal shaft fixing portion 17c and the crankshaft fixing portion 17b of the third crank arm member 17 on the proximal end side and the distal end side. For this reason, no internal space is formed for this portion.

  Further, a through hole 18c is formed in the fourth bottom portion 18a on the base end side. The through hole 18 c is disposed concentrically with the crankshaft fixing hole 17 d of the third crank arm member 17. Further, a through hole 18d for inserting the pedal shaft is formed in the fourth bottom portion 18a on the distal end side. The through hole 18d is arranged concentrically with the pedal mounting hole of the third crank arm.

  In the left crank 13 having the above configuration, the third crank arm member 17 and the fourth crank arm member 18 are in contact with each other between the third crank arm member 17 and the fourth crank arm member 18 as described above. An internal space S2 is formed. In this state, the third crank arm member 17 and the fourth crank arm member 18 are joined by diffusion bonding at a portion T2 (contact portion) where the third crank arm member 17 and the fourth crank arm member 18 abut. Be joined.

  As shown in FIG. 7, one end of the crankshaft 11 is fixed to the right crank 12. Specifically, one end of the crankshaft 11 is spline-fitted into the crankshaft fixing hole 35h of the first crank arm member 15 from the upper side in FIG. 3A. The other end of the crankshaft 11 is fixed to the left crank 13. The other end of the crankshaft 11 is spline-fitted into a crankshaft fixing hole 17 d of the third crank arm member 17 shown in FIG. 4 and fixed by an axle bolt 19.

  The crankshaft 11 includes a first outer tubular member 28 (an example of a first shaft member) and a first inner member 29 (an example of a second shaft member). Here, the first outer tubular member 28 is made of a metal (an example of the first material) such as an aluminum alloy, for example. The first inner member 29 is made of, for example, a metal such as an iron alloy (an example of a second material).

  The first outer tubular member 28 is rotatably supported by a bottom bracket structure 33 provided on the hanger portion of the bicycle frame. The first outer tubular member 28 is formed in a hollow tubular shape.

  First and second spline teeth (not shown) are formed at both ends of the first outer tubular member 28. For example, one end of the crankshaft 11 is fixed to the right crank 12 by press-fitting the first spline teeth into the spline groove of the crankshaft fixing hole 35 h in the first crank arm member 15. Further, the second spline teeth are fitted into the spline groove in the crankshaft fixing hole 17d of the third crank arm member 17, and the axle bolt 19 is screwed into the inner peripheral portion of the first inner member 29, whereby the crankshaft The other end of 11 is fixed to the left crank 13.

  The first inner member 29 is formed in a hollow tubular shape. The first inner member 29 is disposed inside the first outer tubular member 28. Specifically, the first inner member 29 is disposed inside the first outer tubular member 28 in a state where the outer peripheral surface of the first inner member 29 is in contact with the inner peripheral surface of the first outer tubular member 28. The

  In the crankshaft 11 having the above configuration, a first outer tubular member is formed by diffusion bonding a portion T3 (abutting portion) where the outer peripheral surface of the first inner member 29 and the inner peripheral surface of the first outer tubular member 28 are in contact with each other. The member 28 and the first inner member 29 are joined.

  As described above, in the crank assembly 10, two members are joined by diffusion joining. Here, the first crank arm member 15 and the second crank arm member 16, the third crank arm member 17 and the fourth crank arm member 18, the first outer tubular member 28 and the first inner member 29 are two members. It corresponds to. An example of diffusion bonding will be described below.

  In diffusion bonding, first, two members are brought into close contact with each other. Next, pressurization is performed so as not to cause plastic deformation as much as possible under a temperature condition equal to or lower than the melting point of these two members. This causes atomic diffusion between the joints of the two members, thereby joining the two members together. Note that the insert metal may be melted between the joints of the two members.

  By performing diffusion bonding of the two members in this way, it is difficult for positional displacement at the time of bonding to occur, and the amount of deformation at the time of bonding is small. Thereby, in diffusion bonding, dimensional accuracy can be improved as compared with other bonding methods. Further, the two members can be surface bonded or laminated. Further, even if the two members are made of different materials such as different metals, these two members can be joined to each other. Furthermore, the finish, that is, the appearance of the joint between the two members can be improved as compared with other joining methods.

  In addition, also in the following structures, the example in case two members are joined by diffusion joining is shown. The description of the diffusion bonding is applied mutatis mutandis also in the following configurations.

[Rear sprocket assembly]
As shown in FIGS. 1, 8, and 9, the rear sprocket assembly 20 includes, for example, a first rear sprocket assembly 21 (an example of a rear sprocket assembly) and a second rear sprocket assembly (not shown). ,It is configured. The first rear sprocket assembly 21 and the second rear sprocket assembly 21 are mounted on a rear hub (not shown).

  As shown in FIGS. 8 and 9, the first rear sprocket assembly 21 includes two sprocket body portions 22 and 23 (sprocket body portion, an example of the second material) and a sprocket support portion 24 (sprocket support portion, An example of a first material). The two sprocket body portions 22 and 23 are supported by one sprocket support portion 24.

  Specifically, the sprocket body portions 22 and 23 are formed substantially in an annular shape. Sprocket teeth 22 a and 23 a are provided on the outer peripheral side of the sprocket main body portions 22 and 23. On the inner peripheral side of the sprocket body portions 22 and 23, first mounting portions 22b and 23b to be mounted on the sprocket support portion 24 are provided. Here, a plurality of (for example, six) first mounting portions 22 b and 23 b are provided on the inner peripheral side of the sprocket main body portions 22 and 23. The first mounting portions 22b and 23b are formed so as to protrude from the sprocket body portions 22 and 23 toward the inner peripheral side.

  The sprocket support portion 24 engages with a free wheel of a rear hub (not shown) and supports the sprocket body portions 22 and 23. The sprocket support portion 24 has a base portion 24a and a plurality of arm portions 24b. On the inner peripheral side of the base portion 24a, an engaging portion 24c that engages with the free wheel so as to rotate integrally is provided. A plurality of (for example, six) arm portions 24b are provided on the outer peripheral side of the base portion 24a.

  Specifically, each of the plurality of arm portions 24b extends radially outward from the base portion 24a and is formed at intervals in the circumferential direction. At the tip of the arm portion 24b, a mounted portion 24d to which the sprocket body portion is mounted is provided. The first mounting portions 22b and 23b of the sprocket body portions 22 and 23 are in contact with both surfaces of the mounted portion 24d. In this state, the sprocket body portions 22 and 23 and the sprocket support portion 24 are joined by diffusion joining the portion T4 (contact portion) where the first mounting portions 22b and 23b abut on the mounted portion 24d. . In FIG. 8, the contact portion T4 is hatched.

  The second rear sprocket assembly (not shown) includes a plurality of rear sprockets. Sprocket teeth are also provided on the outer peripheral side of the other plurality of rear sprockets. A spacer ring (not shown) is disposed between two adjacent rear sprockets in the other plurality of rear sprockets. Each rear sprocket and each spacer ring are mounted directly on the freewheel of the rear hub.

  The sprocket body portions 22 and 23 are made of a material such as an iron alloy or a titanium alloy, and the sprocket support portion 24 is made of a material such as an iron alloy or an aluminum alloy, for example.

[Front hub assembly and rear hub assembly]
As shown in FIGS. 1 and 10, the front hub assembly 30 is supported by a front fork 98. The front hub assembly 30 mainly includes a front hub shaft 34, a hub shell 37, a set of bearing assemblies 38, and a wheel fixing structure 39.

  The front hub assembly 30 is the same as the conventional configuration except for the front hub shaft 34. Therefore, here, the front hub shaft 34 will be described, and the description of the hub shell 90, the pair of bearing assemblies 92, and the quick release structure 94 will be omitted.

  Both end portions of the front hub shaft 34 are supported by a front fork 98 and fixed by a wheel fixing structure 39. The front hub shaft 34 is configured substantially in the same manner as the crankshaft 11.

  Specifically, the front hub shaft 34 includes a second outer tubular member 34a (an example of a first shaft member) and a second inner member 34b (an example of a second shaft member). The second outer tubular member 34a is formed in a hollow tubular shape. The second outer tubular member 34a is made of a metal (an example of a first material) such as an iron alloy, for example.

  The second inner member 34b is formed in a hollow tubular shape. The second inner member 34b is made of, for example, a metal such as an aluminum alloy (an example of a second material). The second inner member 34b is disposed inside the second outer tubular member 34a. Specifically, the second inner member 34b is disposed inside the second outer tubular member 34a in a state where the outer peripheral surface of the second inner member 34b is in contact with the inner peripheral surface of the second outer tubular member 34a. The

  In the front hub shaft 34 having the above-described configuration, the second outer side is formed by diffusion bonding a portion T5 (contact portion) where the outer peripheral surface of the second inner member 34b and the inner peripheral surface of the second outer tubular member 34a are in contact. The tubular member 34a and the second inner member 34b are joined.

  The rear hub assembly 40 shown in FIG. 1 is the same as the conventional configuration except for the rear hub shaft 41. Therefore, here, the rear hub shaft 41 will be described, and description of the other components will be omitted. Since the rear hub shaft 41 is substantially the same hub shaft as the front hub shaft 34, the rear hub shaft 41 will be briefly described.

  As shown in FIG. 11, the rear hub shaft 41 includes a third outer tubular member 41a (an example of a first shaft member) and a third inner member 41b (an example of a second shaft member). The hollow third outer tubular member 41a is made of, for example, a metal (an example of the second material) such as an iron alloy. The hollow third inner member 41b is made of, for example, a metal (an example of a first material) such as an aluminum alloy. The third inner member 41b is disposed inside the third outer tubular member 41a in a state where the outer peripheral surface of the third inner member 41b is in contact with the inner peripheral surface of the third outer tubular member 41a.

  In the rear hub shaft 41 having the above-described configuration, a third outer tubular member is formed by diffusion bonding a portion T6 (contact portion) where the outer peripheral surface of the third inner member 41b and the inner peripheral surface of the third outer tubular member 41a are in contact. The member 41a and the third inner member 41b are joined.

[Brake lever]
As shown in FIG. 1, each of the pair of brake levers 110 is swingably attached to a lever bracket 105 attached to a handle. By operating each of these brake levers 110, the front and rear brake devices 108 and 109 are operated. In FIG. 1, only one brake lever 110 is shown. Further, the brake devices 108 and 109 are the same as the conventional configuration, and thus the description thereof is omitted here.

  As shown in FIGS. 12 and 13, each brake lever 110 includes a first lever portion 111 (an example of a first lever portion) and a second lever portion 112 (an example of a second lever portion). The second lever portion 112 is disposed to face the first lever portion 111. Specifically, in a state where the second lever portion 112 is in contact with the first lever portion 111, the first lever portion 111 and the second lever portion 112 are joined by diffusion bonding.

  Here, the 1st lever part 111 is comprised from metals (an example of 1st material), such as an aluminum alloy, for example. The 2nd lever part 112 is comprised, for example from metals, such as an iron alloy (an example of 2nd material).

  Specifically, the first lever portion 111 includes a second attachment portion 111a that is swingably attached to the lever bracket 105 shown in FIG. 1, and an operation portion 111b for operating the lever. A first lever mounting hole 111c is formed in the second mounting portion 111a. The operation part 111b has a fifth bottom part 111d extending in a direction away from the second mounting part 111a, and a fifth edge part 111e extending from the outer edge part of the fifth bottom part 111d in the thickness direction of the fifth bottom part 111d.

  The second lever portion 112 abuts on the first lever portion 111 in the range from the second mounting portion 111 a to the center portion of the first lever portion 111. Specifically, the second lever portion 112 has a pair of third mounting portions 112a and a reinforcing portion 112b. One of the pair of third mounting portions 112a can contact the second mounting portion 111a. The other of the pair of third mounting portions 112a is disposed to face the second mounting portion 111a with a predetermined interval from one of the pair of third mounting portions 112a. A second lever mounting hole 112c is formed in each of the pair of third mounting portions 112a. The pair of second lever mounting holes 112c are formed in the third mounting portion 112a so as to be substantially concentric with the first lever mounting holes 111c.

  The reinforcement part 112b is for reinforcing the operation part 111b. The reinforcing portion 112b preferably includes a facing portion 112d that faces the operation portion 111b, and a plurality of (for example, two) rib portions 112e that reinforce the operation portion 111b. The facing portion 112d abuts on the fifth bottom portion 111d of the operation portion 111b. The rib part 112e is provided in the opposing part 112d, and contact | abuts to a pair of 5th edge part 111e of the operation part 111b. One of the two rib portions 112e is provided at the end of the facing portion 112d, and abuts against the pair of fifth edge portions 111e at the central portion of the operation portion 111b.

  In the brake lever 110 having the above-described configuration, in the first lever portion 111 and the second lever portion 112, the second mounting portion 111a and one third mounting portion 112a, the fifth bottom portion 111d of the operation portion 111b, and the reinforcing portion 112b. The facing portion, the fifth edge portion 111e of the operation portion 111b, and the reinforcing portion 112b are in contact with each other. In this state, the first lever portion 111 and the second lever portion 112 are joined by the diffusion joining of the contact portion T7.

<Other embodiments>
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of invention. In particular, a plurality of embodiments and modifications described in this specification can be arbitrarily combined as necessary.

  (A) In the above embodiment, an example in which the first sprocket 31 constituting the sprocket assembly 50 does not have an internal space has been described. However, the first sprocket 31 may have an internal space.

  In this case, for example, as shown in FIG. 14A, the sprocket assembly 150 includes a first sprocket 131 and a second sprocket 132. The first sprocket 131 includes a front sprocket main body 131a, a front sprocket cover 131b, and a front sprocket sprocket tooth 131c.

  The front sprocket cover 131b is a portion that covers the front sprocket body 131a. The front sprocket cover 131b is made of, for example, an aluminum alloy (an example of the first material).

  The sprocket teeth 131c for the front sprocket are disposed between the front sprocket body 131a and the cover portion 131b for the front sprocket. The sprocket teeth 131c for the front sprocket are supported by a support portion 130 provided between the front sprocket body 131a and the front sprocket cover portion 131b. Here, the plurality of support portions 130 are arranged at intervals in the circumferential direction, and support the sprocket teeth 131c for the front sprocket. The support part 130 is provided in the outer peripheral part of the cover part 131b for front sprockets, for example.

  The front sprocket body 131a is disposed to face the front sprocket cover 131b. The front sprocket body 131a is made of, for example, an iron alloy (an example of a second material).

  Specifically, as shown in FIGS. 14A and 14B, the front sprocket body 131a includes a base body 231a and a cover support 231b. The base portion 231a is formed in a substantially annular shape. The base portion 231a is disposed to face the front sprocket cover portion 131b. The cover support portion 231b is formed integrally with the base portion 231a. Here, the plurality of cover support portions 231b are provided on the base portion 231a at intervals in the circumferential direction. Each cover support part 231b contacts the cover part 131b for the front sprocket.

  As a result, an internal space S3 is formed between the base portion 231a and the front sprocket cover portion 131b. In detail, between the cover support portions 231b adjacent to each other in the circumferential direction, between the base portion 231a and the front sprocket cover portion 131b, and between the sprocket teeth 131c for the front sprocket and the sprocket mounting portion 35, A space S3 is formed.

  In this state, the front sprocket body 131a and the front sprocket cover 131b are joined by diffusion joining the portion T8 (contact portion) where the cover support portion 231b and the front sprocket cover 131b abut. Is done. In FIG. 14B, only the rib-like contact portion T8 (portion corresponding to FIG. 14A) in the cover support portion 231b is assigned a reference numeral.

  Further, the sprocket teeth 131c for the front sprocket are diffusion-bonded to the outer peripheral portion of the front sprocket main body 131a (base portion 231a) and the portion T9 (contact portion) that contacts the outer peripheral portion of the cover portion 131b for the front sprocket. Thus, the sprocket teeth 131c for the front sprocket are joined to the front sprocket main body 131a and the cover portion 131b for the front sprocket. By configuring in this way, it is possible to obtain the same effect as in the above embodiment.

  (B) Although the first crank arm member 15 and the second crank arm member 16 are integrally formed in the right crank 12 in the above-described embodiment, the first crank arm member 15 and the first crank arm member 15 At least one of the two crank arm members 16 may be composed of a plurality of members.

  Here, the right crank 112 will be described as an example, but the third crank arm member 17 and the fourth crank arm member 18 in the left crank 13 of the above embodiment are also configured similarly to the right crank 12 shown here. May be.

The description of the right crank 112 described here is a description of parts different from the above-described embodiment, and the description omitted here is based on the above-described embodiment.
As shown in FIG. 15A, the right crank 112 includes a fifth crank arm member 115 and a sixth crank arm member 116.

  Since the fifth crank arm member 115 has the same configuration as the first crank arm member 15 of the above-described embodiment, the description thereof is omitted here. About the structure which abbreviate | omitted description here, it applies to description of the said embodiment.

  The sixth crank arm member 116 includes a first cover portion 136 (an example of a first member) and a third arm portion 126 (an example of a second member).

  The material constituting each of the first cover part 136 and the third arm part 126 includes, for example, any one of iron, aluminum, and titanium. Here, each of the 1st cover part 136 and the 3rd arm part 126 is comprised, for example from metals, such as an aluminum alloy. Instead of this, each of the first cover portion 136 and the third arm portion 126 may be made of a metal such as an iron alloy or a metal such as a titanium alloy, for example.

  Here, an example in which the first cover portion 136 and the third arm portion 126 are made of the same kind of metal material has been shown, but either one of the materials of the first cover portion 136 and the third arm portion 126 ( An example of the first material may be different from the other material (an example of the second material) of the first cover part 136 and the third arm part 126. In this case, under the condition that the material of each member is different, the material of each member includes, for example, any one of iron, aluminum, and titanium.

  Below, the structure of the 1st cover part 136 and the structure of the 3rd arm part 126 are demonstrated.

  The 1st cover part 136 is a part which covers the sprocket attaching part 35 shown to the said embodiment. The first cover part 136 is formed by forging. The 1st cover part 136 has the 1st junction part 136a. The first joint portion 136a is formed on the third arm portion 126 side.

  The third arm portion 126 is a portion that covers the first arm portion 25 shown in the embodiment. The third arm portion 126 is formed by a process different from forging. For example, the third arm portion 126 is formed by bending. More specifically, the third arm portion 126 is formed by bending a plate-like member. The third arm portion 126 has a second joint portion 126a. The second joint portion 126a is formed on the first cover portion 136 side. As shown in FIG. 15B, the second bonding portion 126a is preferably formed in a stepped shape. The first joint portion 136a of the first cover portion 136 abuts on the step-shaped second joint portion 126a. In FIG. 15A and FIG. 15B, the part (contact part) which the 1st junction part 136a contact | abuts to the 2nd junction part 126a is shown with the code | symbol T10. Thus, by forming the second joint portion 126a of the third arm portion 126 in a step shape, the joint area of the first cover portion 136 with the first joint portion 136a can be increased. Instead of forming the second joint portion 126a of the third arm portion 126 in a step shape, the first joint portion 136a of the first cover portion 136a may be formed in a step shape.

  The 1st cover part 136 and the 3rd arm part 126 which have said structure are joined by diffusion bonding. Specifically, in a state where the first joint portion 136a of the first cover portion 136 and the second joint portion 126a of the third arm portion 126 are in contact with each other, the first joint portion 136a and the second joint portion 126a are diffused. Joined by joining. Thereby, the sixth crank arm member 116 (the first cover portion 136 and the third arm portion 126) functions as one member. By configuring in this way, it is possible to obtain the same effect as in the above embodiment.

  The fifth crank arm member 115 and the sixth crank arm member 116 are diffusion-bonded in the same manner as in the above embodiment.

  (C) In the other embodiment (b), an example in which the sixth crank arm member 116 (the first cover portion 136 and the third arm portion 126) functions as one member by diffusion bonding is shown. . In addition, the fifth crank arm member 115 may also function as one member by diffusion bonding.

  The description of the fifth crank arm member 215 (right crank 212) described here is a description of parts different from the above embodiment, and the description omitted here is in accordance with the above embodiment.

  For example, as shown in FIG. 16A, the fifth crank arm member 115 includes a sprocket mounting portion 235 (an example of a first member), a fourth arm portion 225 (an example of a second member), and a pedal shaft mounting portion 245 ( An example of a third member).

  The material constituting each of the sprocket attachment portion 235, the fourth arm portion 225, and the pedal shaft attachment portion 245 includes, for example, any one of iron, aluminum, and titanium. Here, each of the sprocket mounting portion 235, the fourth arm portion 225, and the pedal shaft mounting portion 245 is made of a metal such as an iron alloy, for example. Instead of this, each of the sprocket mounting portion 235, the fourth arm portion 225, and the pedal shaft mounting portion 245 may be made of, for example, a metal such as an aluminum alloy or a metal such as a titanium alloy.

  Here, an example in which each of the sprocket mounting portion 235, the fourth arm portion 225, and the pedal shaft mounting portion 245 is made of the same kind of metal material has been shown, but the sprocket mounting portion 235, the fourth arm portion 225, And two or all of the pedal shaft attachments 245 may be of different materials. In this case, under the condition that the material of each member is different, the material of each member includes, for example, any one of iron, aluminum, and titanium.

  Below, each structure of the sprocket attachment part 235, the 4th arm part 225, and the pedal shaft attachment part 245 is demonstrated.

The crankshaft 11 (see FIG. 2) can be attached to the sprocket attachment portion 235. For example, the sprocket mounting portion 235 has a crankshaft mounting hole 235h (an example of a first shaft mounting portion), and the crankshaft 11 can be mounted in the crankshaft mounting hole 235h. More specifically, one end of the crankshaft 11 is press-fitted into the crankshaft mounting hole 235.
The sprocket mounting portion 235 is disposed to face the first cover portion 136 (see FIG. 15A). The sprocket mounting portion 235 is formed by forging. The sprocket mounting portion 235 has a third joint portion 235a. The third joint portion 235a is formed on the fourth arm portion 225 side.

  The fourth arm portion 225 is a portion that connects the sprocket attachment portion 235 and the pedal shaft attachment portion 245. The fourth arm portion 225 is disposed to face the third arm portion 126 (see FIG. 15A). The fourth arm portion 225 is formed by a process different from forging. For example, the fourth arm portion 225 is formed by bending. More specifically, the 4th arm part 225 is shape | molded by bending a plate-shaped member.

  The fourth arm portion 225 includes a fourth joint portion 225a and a fifth joint portion 225b. The fourth joint portion 225a is formed on the sprocket attachment portion 235 side. The fifth joint portion 225b is formed on the pedal shaft attachment portion 245 side. Each of the fourth joint portion 225a and the fifth joint portion 225b is formed in a step shape (see FIG. 16B). The third joint portion 235a of the sprocket mounting portion 235 comes into contact with the step-like fourth joint portion 225a. A sixth joint portion 245a of a pedal shaft attachment portion 245 described later contacts the step-like fifth joint portion 225b. In this way, by forming the fourth joint portion 225a and the fifth joint portion 225b of the fourth arm portion 225 in a stepped shape, the third joint portion 235a of the sprocket attachment portion 235 and the sixth of the pedal shaft attachment portion 245 are formed. The joint area with the joint portion 245a can be increased. Instead of forming the fourth joint portion 225a and the fifth joint portion 225b of the fourth arm portion 225 in a stepped shape, the third joint portion 235a of the sprocket attachment portion 235 and the sixth joint portion of the pedal shaft attachment portion 245 245a may be formed in a step shape.

  In FIG. 16A and FIG. 16B, a portion (contact portion) where the third joint portion 235a abuts on the fourth joint portion 225a is denoted by reference numeral T11. A portion (contact portion) where the sixth joint portion 245a abuts on the fifth joint portion 225b is denoted by reference numeral T12.

  A pedal shaft (not shown) can be attached to the pedal shaft mounting portion 245. For example, the pedal shaft mounting portion 245 has a pedal mounting hole 245b (an example of a second shaft mounting portion). A pedal shaft can be attached to the pedal mounting hole 245b. More specifically, one end of the pedal shaft is screwed into the pedal mounting hole 245b.

  The pedal shaft attachment portion 245 is disposed to face the third arm portion 126 (see FIG. 15A). The pedal shaft mounting portion 245 is formed by forging. The pedal shaft attachment portion 245 has a sixth connection portion 245a. The sixth connection portion 245a is formed on the fourth arm portion 225 side. The sixth joint 245a contacts the step-like fifth joint 225b.

  The sprocket attachment portion 235, the fourth arm portion 225, and the pedal shaft attachment portion 245 having the above configuration are joined by diffusion bonding. Specifically, the third joint portion 235a of the sprocket attachment portion 235 is joined to the fourth joint portion 225a of the fourth arm portion 225 by diffusion joining. Further, the sixth joint portion 245a of the pedal shaft attachment portion 245 is joined to the fifth joint portion 225b of the fourth arm portion 225 by diffusion joining. Accordingly, the fifth crank arm member 115 (sprocket mounting portion 235, fourth arm portion 225, and pedal shaft mounting portion 245) functions as one member. By configuring in this way, it is possible to obtain the same effect as in the above embodiment.

  Also in this case, the fifth crank arm member 115 and the sixth crank arm member 116 are diffusion-bonded in the same form as in the above embodiment.

  (D) In said other embodiment (c), the example in case the sprocket attaching part 235, the 3rd arm part 225, and the pedal shaft attaching part 245 were joined by diffusion joining was shown. Instead of this, either the sprocket mounting portion 235 or the pedal shaft mounting portion 245 may be formed integrally with the third arm portion 225. In this case, the other of the sprocket mounting portion 235 and the pedal shaft mounting portion 245 and the third arm portion 225 are diffusion bonded. In this configuration, the other of the sprocket mounting portion 235 and the pedal shaft mounting portion 245 corresponds to an example of the first member, and the third arm portion 225 (either the sprocket mounting portion 235 or the pedal shaft mounting portion 245). (Including one) corresponds to an example of the second member. Even if comprised in this way, the effect similar to the said embodiment can be acquired.

  (E) In the other embodiment (d), an example has been shown in which both the fifth crank arm member 215 and the sixth crank arm member 116 function as one member by diffusion bonding. Instead, the fifth crank arm member 215 is configured in accordance with the other embodiment (d), and the sixth crank arm member 116 is configured in the same manner as in the embodiment shown in FIGS. 1 to 14B. Also good. Even if comprised in this way, the effect similar to the said embodiment can be acquired.

  (F) In the above embodiment, the crank assembly 10, the rear sprocket assembly 20, the front hub assembly 30, the rear hub assembly 40, the brake lever 110, and the sprocket assembly 50, which are bicycle parts, are Although an example in which the invention is applied is shown, the present invention is not limited to this. That is, the present invention can be applied to other bicycle parts. For example, the present invention can be applied to a front derailleur, a rear derailleur, a shift lever, and the like. More specifically, the present invention can be applied to a chain guide for a front derailleur, a chain guide for a rear derailleur, and the like.

  (G) In the above-described embodiment, an example in which the first sprocket 31 and the second sprocket 32 are fixed to the sprocket mounting portion 35 by the fixing bolt 35g is shown. However, the first sprocket 31 and the second sprocket 32 are The sprocket attachment portion 35 may be joined by diffusion joining. In this case, the first sprocket 31 and the second sprocket 32 can be diffusion bonded to the sprocket mounting portion 35 in the same manner as the diffusion bonding shown in the first rear sprocket assembly 21 of the above embodiment.

  (H) In the above embodiment, an example in which the internal spaces S1, S2, and S3 are hollow has been described. However, a filler such as a foam member may be disposed in the internal spaces S1, S2, and S3.

  (I) In the above-described embodiment, an example in which a plurality of bicycle parts are diffusion bonded is shown. However, not all the above bicycle parts are diffusion bonded, but at least one bicycle part is diffusion bonded. It may be.

DESCRIPTION OF SYMBOLS 10 Crank assembly 11 Crankshaft 15, 16, 17, 18 1st-4th crank arm member 20 Rear sprocket assembly 22, 23 Sprocket main-body part 24 Sprocket support part 30 Front hub assembly 34 Front hub axis 40 Rear hub assembly 41 Rear hub shaft 50 Sprocket assembly 110 Brake lever 111 First lever portion 112 Second lever portion S1 to S3 Internal space T1 to T12 Contact portion

  The present invention relates to a bicycle component, a bicycle shaft member, a bicycle rear sprocket assembly, and a bicycle lever member.

  In a conventional bicycle part, a plurality of members are joined together by bonding, brazing, laser welding or the like, and configured as one bicycle part. If it demonstrates using a crank arm as an example, the conventional crank arm will have a crank body and a lid member joined to a crank body by adhesion or welding (for example, patent documents 1 and patent documents 2). reference).

JP 2008-001287 A US Pat. No. 5,988,016

  In a conventional bicycle component, for example, a crank arm, when the lid member is joined to the crank body by an adhesive, it is necessary to set a sufficient joining area to ensure a necessary joining strength. Further, in this case, the bonding line of the bonded portion may impair the appearance of the component. Further, in the crank arm, when the lid member is joined to the crank body by welding, there is a possibility that the weld mark at the joined portion may damage the appearance of the part. Furthermore, in joining by bonding or welding, it is necessary to add an adhesive or a filler material, which may increase the weight of the crank arm.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a bicycle component that can simultaneously realize improvement in joint strength, weight reduction, and improvement in appearance. is there.

  A bicycle component according to the present invention includes a first member and a second member disposed to face the first member. An internal space is formed between the first member and the second member. The first member and the second member are joined by diffusion joining.

  In this bicycle part, since the first member and the second member are joined by diffusion joining, the joining strength between the first member and the second member can be improved as compared with joining by adhesion or welding. . Further, even if an internal space is formed between the first member and the second member and the bonding area is reduced, the bonding strength between the first member and the second member can be sufficiently secured by diffusion bonding. it can. That is, the bicycle component can be reduced in weight. Furthermore, in diffusion bonding, since no adhesive sticking out or welding marks are generated, the appearance of bicycle parts can be improved. That is, with this bicycle component, it is possible to simultaneously improve the bonding strength, reduce the weight, and improve the appearance.

  The bicycle component according to the present invention may be configured as follows. One of the first member and the second member is made of the first material. One of the first member and the second member is made of a second material different from the first material.

  In this case, even if the first member and the second member are made of different materials, the first member and the second member can be reliably bonded by diffusion bonding.

  The bicycle component according to the present invention may be configured as follows. The first material is an aluminum alloy. The second material is an iron alloy.

  In this case, since the first material is an aluminum alloy, the bicycle component can be reduced in weight. Moreover, since the second material is an iron alloy, the rigidity of the bicycle part can be ensured. That is, by joining the first member and the second member by diffusion bonding, it is possible to reduce the weight of the bicycle component while ensuring the rigidity of the bicycle component.

  The bicycle component according to the present invention may be configured as follows. The first member and the second member are made of the same kind of metal material.

  In this case, sufficient bonding strength can be ensured, and the bonding line between the first member and the second member can be made less noticeable. That is, the appearance of the bicycle component can be further improved.

  The bicycle component according to the present invention may be configured as follows. The first member has a first base portion, a first side surface portion, and a second side surface portion. The first side surface portion extends from one end portion of the first base body portion in the thickness direction of the first base body portion. The second side surface portion extends from the other end portion of the first base body portion in the thickness direction of the first base body portion and faces the first side surface portion. The second member is disposed to face the first base portion. The first side surface portion and the second side surface portion are joined to the second member by diffusion bonding.

  In this case, an internal space is formed by the first base portion of the first member, the first side surface portion of the first member, the second side surface portion of the first member, and the second member. In this state, the first side surface portion and the second side surface portion are joined to the second member by diffusion bonding. That is, by forming the internal space, even if the bonding area between the first side surface portion and the second side surface portion and the second member is reduced, the first member and the second member are securely connected by diffusion bonding. Can be joined.

  The bicycle component according to the present invention may be configured as follows. The second member is plate-shaped.

  In this case, the first member and the second member can be reliably bonded even if the bonding area between the first side surface portion and the second side surface portion of the first member and the plate-shaped second member is small.

  The bicycle component according to the present invention may be configured as follows. The second member has a second base part, a third side part, and a fourth side part. The third side surface portion extends from the one end portion of the second base portion in the thickness direction of the second base portion. The fourth side surface portion extends from the other end portion of the second base body portion in the thickness direction of the second base body portion, and faces the third side surface portion. The second base portion is disposed to face the first base portion. One of the first side surface portion and the second side surface portion and one of the third side surface portion and the fourth side surface portion are joined by diffusion bonding. Either the first side surface portion or the second side surface portion and the other side of the third side surface portion or the fourth side surface portion are joined by diffusion bonding.

  In this case, the first base part of the first member, the first side part of the first member, the second side part of the first member, the second base part of the second member, the third side part of the second member, and the first An internal space is formed by the fourth side surface portion of the two members. In this state, the first member and the second member are diffusion-bonded at the side portions. That is, by forming the internal space, the first member and the second member can be reliably bonded by diffusion bonding even if the bonding area between the side surface portions is reduced.

  The bicycle component according to the present invention may be configured as follows. A crank arm is constituted by the first member and the second member.

  In this case, the crank arm is constituted by the first member and the second member. That is, by diffusion-bonding the first member and the second member, as described above, it is possible to improve the joint strength, the weight, and the appearance of the crank arm.

  The bicycle component according to the present invention may be configured as follows. A front sprocket assembly is constituted by the first member and the second member.

  In this case, the front sprocket assembly is constituted by the first member and the second member. That is, by diffusion bonding the first member and the second member, in the front sprocket assembly, as described above, it is possible to improve the bonding strength, reduce the weight, and improve the appearance.

  A bicycle shaft member according to the present invention includes a hollow first shaft member and a second shaft member disposed inside the first shaft member. The first shaft member and the second shaft member are joined by diffusion joining.

  In the bicycle shaft member, the first shaft member and the second shaft member are joined by diffusion bonding in a state where the second shaft member is disposed inside the hollow first shaft member. Thereby, compared with the joining by adhesion | attachment or welding, the joining strength of a 1st member and a 2nd member can be improved. Moreover, even if the bonding area between the first member and the second member is small, the bonding strength between the first member and the second member can be sufficiently ensured by diffusion bonding. That is, the bicycle shaft member can be reduced in weight. Furthermore, in the diffusion bonding, no sticking out of the adhesive or welding marks occurs, so that the appearance of the bicycle shaft member can be improved. That is, with this bicycle shaft member, it is possible to simultaneously improve the bonding strength, reduce the weight, and improve the appearance.

  The bicycle shaft member according to the present invention may be configured as follows. One of the first shaft member and the second shaft member is made of the first material. One of the first shaft member and the second shaft member is made of a second material different from the first material.

  In this case, even if the first member and the second member are made of different materials, the first member and the second member can be reliably bonded by diffusion bonding.

  The bicycle shaft member according to the present invention may be configured as follows. The first material is an aluminum alloy. The second material is an iron alloy.

  In this case, since the first material is an aluminum alloy, the bicycle shaft member can be reduced in weight. Moreover, since the second material is an iron alloy, the rigidity of the bicycle shaft member can be ensured. That is, by joining the first member and the second member by diffusion bonding, it is possible to reduce the weight of the bicycle shaft member while ensuring the rigidity of the bicycle shaft member.

  The bicycle shaft member according to the present invention may be configured as follows. The second shaft member is a hollow member. A crankshaft is constituted by the first shaft member and the second shaft member.

  In this case, the crankshaft is constituted by the first member and the second member. That is, by diffusion bonding the first member and the second member, as described above, in the crankshaft, the joint strength is improved, the weight of the second member is hollow in addition to the first member, and An improvement in appearance can be realized.

  The bicycle shaft member according to the present invention may be configured as follows. The second shaft member is a hollow member. A hub shaft is constituted by the first shaft member and the second shaft member.

  In this case, the hub shaft is constituted by the first member and the second member. That is, by diffusion-bonding the first member and the second member, as described above, in the hub axle, the joint strength is improved, the weight of the second member is hollow in addition to the first member, and An improvement in appearance can be realized.

  A bicycle rear sprocket assembly according to the present invention includes a sprocket body and a sprocket support that supports the sprocket body. The sprocket body and the sprocket support are joined by diffusion bonding.

  In the bicycle rear sprocket assembly, the sprocket body and the sprocket support are joined by diffusion bonding in a state where the sprocket body is supported by the sprocket support. Thereby, compared with the joining by adhesion | attachment or welding, the joining strength of a sprocket main-body part and a sprocket support part can be improved. Moreover, even if the joining area between the sprocket body and the sprocket support is small, the joining strength between the sprocket body and the sprocket support can be sufficiently secured by diffusion joining. Furthermore, when joining the sprocket body and the sprocket support, a fixing member such as a rivet or bolt is not required. Therefore, the bicycle rear sprocket assembly can be reduced in weight. Further, since diffusion bonding does not cause adhesive sticking or welding marks, the appearance of the bicycle rear sprocket assembly can be improved. That is, in this bicycle rear sprocket assembly, it is possible to simultaneously improve the joint strength, reduce the weight, and improve the appearance.

  The bicycle rear sprocket assembly according to the present invention may be configured as follows. One of the sprocket body and the sprocket support is made of the first material. The other of the sprocket body and the sprocket support is made of a second material different from the first material.

  In this case, even if the sprocket main body and the sprocket support are made of different materials, the sprocket main body and the sprocket support can be reliably bonded by diffusion bonding.

  The bicycle rear sprocket assembly according to the present invention may be configured as follows. The first material is an aluminum alloy. The second material is an iron alloy.

  In this case, since the first material is an aluminum alloy, the bicycle rear sprocket assembly can be reduced in weight. Further, since the second material is an iron alloy, the rigidity of the bicycle rear sprocket assembly can be ensured. That is, by joining the bicycle rear sprocket main body portion and the sprocket support portion by diffusion bonding, it is possible to reduce the weight of the rear sprocket assembly while ensuring the rigidity of the bicycle rear sprocket assembly.

  The bicycle lever member according to the present invention includes a first lever portion and a second lever portion disposed to face the first lever portion. The first lever part and the second lever part are joined by diffusion joining.

  In the bicycle lever member, the first lever portion and the second lever portion are joined by diffusion bonding in a state where the second lever portion is disposed to face the first lever portion. Thereby, compared with joining by adhesion | attachment or welding, the joining strength of a 1st lever part and a 2nd lever part can be improved. Further, even if the joining area between the first lever part and the second lever part is small, the joining strength between the first lever part and the second lever part can be sufficiently secured by diffusion joining. That is, the weight of the bicycle lever member can be reduced. Furthermore, in the diffusion bonding, since no sticking out of the adhesive or welding marks occur, the appearance of the bicycle lever member can be improved. That is, with this bicycle lever member, it is possible to simultaneously improve the bonding strength, reduce the weight, and improve the appearance.

  The bicycle lever member according to the present invention may be configured as follows. One of the first lever portion and the second lever body is made of the first material. Either one of the first lever portion and the second lever body is made of a second material different from the first material.

  In this case, even if the first lever portion and the second lever body are made of different materials, the first lever portion and the second lever body can be reliably bonded by diffusion bonding.

  The bicycle lever member according to the present invention may be configured as follows. The first material is an aluminum alloy. The second material is an iron alloy.

  In this case, since the first material is an aluminum alloy, the bicycle lever member can be reduced in weight. Moreover, since the second material is an iron alloy, the rigidity of the bicycle lever member can be ensured. That is, by joining the first lever portion and the second lever portion by diffusion bonding, it is possible to reduce the weight of the bicycle lever member while ensuring the rigidity of the bicycle lever member.

  The bicycle component according to the present invention includes a first member and a second member. The first member is formed by forging. The first member and the second member are joined by diffusion bonding.

  In this bicycle part, since the first member and the second member are joined by diffusion joining, the joining strength between the first member and the second member can be improved compared to joining by adhesion or welding. it can. Moreover, even if the first member is formed by forging, this effect can be obtained. Furthermore, in diffusion bonding, since no adhesive sticking out or welding marks are generated, the appearance of bicycle parts can be improved. That is, with this bicycle component, it is possible to simultaneously improve joint strength and appearance.

  The bicycle component according to the present invention may be configured as follows. The first member and the second member are made of the same material.

  In this case, the first member and the second member are made of the same material, and the first member and the second member can be reliably bonded by diffusion bonding. Furthermore, the joint line between the first member and the second member can be made less noticeable. That is, the appearance of the bicycle component can be further improved.

  The bicycle component according to the present invention may be configured as follows. The first member and the second member include any one of iron, aluminum, and titanium.

  In this case, the first member and the second member are made of the same material, and the first member and the second member contain any one of iron, aluminum, and titanium. The rigidity can be improved and / or the weight can be reduced.

  The bicycle component according to the present invention may be configured as follows. One of the first member and the second member is made of the first material. One of the first member and the second member is made of a second material different from the first material.

  In this case, even if the first member and the second member are made of different materials, the first member and the second member can be reliably bonded by diffusion bonding.

  The bicycle component according to the present invention may be configured as follows. The first material includes any one of iron, aluminum, and titanium. The second material includes any one of iron, aluminum, and titanium.

  In this case, even if the first member and the second member are made of different materials, the first member and the second member contain any one of iron, aluminum, and titanium. It is possible to improve the rigidity of the component and / or reduce the weight.

  The bicycle component according to the present invention may be configured as follows. The second member is formed by a process different from forging.

  In this case, even if the second member is formed by a process different from forging, the first member and the second member can be reliably bonded by diffusion bonding.

  The bicycle component according to the present invention may be configured as follows. The second member is formed by a bending process different from forging.

  In this case, even if the second member is formed by bending, the first member and the second member can be reliably bonded by diffusion bonding. Furthermore, since the second member can be thinned, the weight of the bicycle part can be reduced.

  The bicycle component according to the present invention may be configured as follows. The second member is a plate member and is formed by a process different from forging, for example, a bending process.

  In this case, even if the second member is a plate member, the first member and the second member can be reliably bonded using diffusion bonding by performing the above processing. Furthermore, since it is easier to reduce the thickness of the second member, the weight of the bicycle part can be easily reduced.

  The bicycle component according to the present invention may be configured as follows. The bicycle component further includes a third member molded by forging. The third member is diffusion bonded to at least one of the first member and the second member.

  In this case, even if the bicycle component further includes the third member in addition to the first member and the second member, the joint strength can be improved and the appearance can be improved simultaneously by diffusion bonding. .

  The bicycle component according to the present invention may be configured as follows. The first member has a first shaft mounting portion for mounting the first shaft member.

  In this case, since the first member has the first shaft attachment portion, the first shaft member can be attached to the first member.

  The bicycle component according to the present invention may be configured as follows. The third member has a second shaft mounting portion for mounting the second shaft member.

In this case, since the 3rd member has the 2nd axis attachment part, the 2nd axis member can be attached to the 3rd member.

  The bicycle component according to the present invention may be configured as follows. The first member, the second member, and the third member constitute a crank arm. A crankshaft can be attached to the first shaft attachment portion. A pedal shaft can be attached to the second shaft attachment portion.

  In this case, even if the crank arm is constituted by the first member, the second member, and the third member, the bonding strength is improved by diffusion bonding the first member, the second member, and the third member. In addition, the appearance can be improved at the same time.

  According to the present invention, in a bicycle part, it is possible to simultaneously improve joint strength, weight reduction, and appearance. The same effect can be realized in the bicycle shaft member, the bicycle rear sprocket assembly, and the bicycle lever member.

1 is a side view of a bicycle according to an embodiment of the present invention. Right crank side view The disassembled perspective view of the 1st crank arm member and 2nd crank arm member in a right crank. Sectional drawing in the center part of a right crank. The perspective view of a left crank. Sectional drawing of the cutting line VV of FIG. Sectional drawing of the cutting line VI-VI of FIG. Sectional drawing of a crank assembly. The side view of a rear sprocket assembly (1st rear sprocket assembly). The fragmentary sectional view of a rear sprocket assembly (1st rear sprocket assembly). The side view and sectional drawing of a front hub assembly. The side view and sectional drawing of a rear hub axis | shaft. The perspective view of a brake lever (the 1). The perspective view of a brake lever (the 2). FIG. 6 is a partial cross-sectional view of a sprocket assembly according to another embodiment of the present invention. The front view of the cover support part of the sprocket assembly by other embodiment of this invention. The disassembled perspective view of the 5th crank arm member and the 6th crank arm member in the right crank by other embodiment of this invention. FIG. 15B is a cross-sectional view taken along section line XVB-XVB in FIG. 15A. The disassembled perspective view of the 5th crank arm member in the right crank by other embodiment of this invention. FIG. 16B is a partially enlarged view of the fifth crank arm member of FIG. 16A as viewed from above.

[Overall configuration of bicycle]
In FIG. 1, a bicycle 101 employing one embodiment of the present invention mainly includes a frame 102, a handle 104, a drive unit 105, front and rear wheels 106 and 107, and front and rear brake devices 108 and 109. Is provided.

  The frame 102 has a front fork 98. The handle 104 is fixed to the front fork 98. The drive unit 105 mainly includes a crank assembly 10 and a rear sprocket assembly 20. The front and rear wheels 106 and 107 are attached to the front fork 98 and the rear portion of the frame 102 via the front hub assembly 30 and the rear hub assembly 40. The front and rear brake devices 108 and 109 are operated by operating the brake lever 110. Since the front and rear brake devices 108 and 109 are the same as the conventional configuration, the description thereof is omitted here.

[Configuration of crank assembly]
As shown in FIGS. 1 to 7, the crank assembly 10 includes a right crank 12, a left crank 13, and a crankshaft 11.

  As shown in FIGS. 2, 3A and 3B, the right crank 12 includes a first crank arm member 15 (an example of a first member) and a second crank arm member 16 (an example of a second member). Have. The first crank arm member 15 and the second crank arm member 16 are disposed to face each other. Further, an internal space S <b> 1 is formed between the first crank arm member 15 and the second crank arm member 16. In this state, the first crank arm member 15 and the second crank arm member 16 are joined by diffusion joining.

  Here, the 1st crank arm member 15 is comprised from metals, such as an iron alloy (an example of 2nd material), for example. The second crank arm member 16 is made of a metal (an example of the first material) such as an aluminum alloy, for example. Instead, the first crank arm member 15 and the second crank arm member 16 may be made of the same kind of metal material such as an aluminum alloy. In this case, the joining line between the first crank arm member 15 and the second crank arm member 16 is further inconspicuous while ensuring sufficient joining strength. That is, the appearance can be further improved.

  Specifically, the first crank arm member 15 includes a first arm portion 25 and a sprocket mounting portion 35.

  The first arm portion 25 includes a first bottom portion 25a (an example of a first base portion), a pair of first edge portions 25b (an example of a first side surface portion and a second side surface portion), and a fixed portion 25c for a pedal shaft. And a first step portion 25d.

  The first bottom portion 25a is a portion extending in the radial direction with respect to the crankshaft 11. The 1st bottom part 25a is arrange | positioned facing the 2nd bottom part of the 2nd arm member mentioned later. A pair of 1st edge part 25b is a part extended in the thickness direction of the 1st bottom part 25a from the outer edge part of the 1st bottom part 25a. The pair of first edge portions 25b are formed integrally with the first bottom portion 25a so as to face each other. The angle formed by the first edge 25b and the first bottom 25a may be any angle.

  The pedal shaft fixing portion 25c is formed on the distal end side of the first bottom portion 25a. The fixed portion 25c for the pedal shaft is integrally formed on the distal end side of the first bottom portion 25a. A pedal mounting hole 25e for mounting a pedal shaft (not shown) is formed in the pedal shaft fixing portion 25c.

The first step portion 25d is formed on the outer periphery of the pedal shaft fixing portion 25c. Specifically, the first step portion 25d is continuously formed from the first edge portion 25b to the outer peripheral portion of the pedal shaft fixing portion 25c.

  The sprocket mounting portion 35 includes first to fourth sprocket mounting arm portions 35a to 35d, a second stepped portion 35e, and a crankshaft fixing portion 35f.

  Sprocket mounting holes are provided at the tip ends of the first to fourth sprocket mounting arm portions 35a to 35d. A sprocket assembly 50 composed of the first sprocket 31 and the second sprocket 32 is disposed at the tip of the first to fourth sprocket mounting arm portions 35a to 35d. Specifically, the first sprocket 31 and the second sprocket 32 are disposed on both sides of the tip end portions of the first to fourth sprocket mounting arm portions 35a to 35d. In this state, the first sprocket 31 and the second sprocket 32 are fixed to the sprocket mounting portion 35 by the fixing bolt 35g (see FIG. 1).

  Note that the configuration of the sprocket assembly 50 is the same as the conventional configuration, and thus detailed description thereof is omitted here. The first sprocket 31 and the second sprocket 32 may be interpreted as the first sprocket assembly 31 and the second sprocket assembly 32.

  The second step portion 35e is formed integrally with the outer peripheral portion of the first to fourth sprocket mounting arm portions 35a to 35d (excluding the sprocket mounting hole portion). Here, in the first and fourth sprocket mounting arm portions 35a and 35d, the second step portion 35e formed in the first arm portion 25 is continuously formed from the first edge portion 25b. Further, the second step portion 35e is formed on the same plane as the tip portion (contact portion) of the first edge portion 25b.

  The crankshaft fixing portion 35 f has a fixing hole 35 h for fixing one end portion of the crankshaft 11. A spline groove is formed in the crankshaft fixing hole 35h.

  The second crank arm member 16 includes a second arm portion 26 and a cover portion 36 that covers the sprocket mounting portion 35.

  The second arm part 26 has a second bottom part 26a (an example of a second base part) and a second edge part 26b (an example of a third side part and a fourth side part). The second bottom portion 26 a is a portion extending in the radial direction with respect to the crankshaft 11. The second bottom portion 26 a is disposed to face the first bottom portion 25 a of the first arm portion 25. A through hole 26d through which the pedal shaft can pass is formed in the second bottom portion 26a on the distal end side of the second arm portion 26. The through hole 26d is disposed concentrically with the pedal mounting hole 25e of the first crank arm member 15.

  The 2nd edge part 26b is a part extended in the thickness direction of the 2nd bottom part 26a from the outer edge part of the 2nd bottom part 26a. The second edge portion 26b is formed integrally with the second bottom portion 26a. On the distal end side of the second arm portion 26, the second edge portion 26 b abuts on the first step portion 25 d of the first crank arm member 15. In the portion excluding the distal end side of the second arm portion 26, the pair of second edge portions 26b face each other. Each of the pair of second edge portions 26b abuts on the first edge portion 25b.

  The cover part 36 is a part that covers the sprocket attachment part 35. The cover portion 36 is formed integrally with the second arm portion 26 on the proximal end side of the second arm portion 26. Specifically, the cover portion 36 includes a third bottom portion 36a and a third edge portion 36b.

The third bottom portion 36 a is disposed to face the sprocket mounting portion 35. Specifically, the third bottom 36 a is in the first to fourth sprocket attachment arm portion 35a to 35d, it abuts.

The third edge 36b is a portion from the outer edge of the third bottom 36 a extending in the thickness direction of the third bottom 36 a. The third edge portion 36b contacts the second stepped portion 35e. That is, substantially no internal space is formed between the cover portion 36 and the sprocket mounting portion 35.

  In the right crank 12 having the above configuration, as described above, the first crank arm member 15 and the second crank arm member 16 are in contact with each other with the first crank arm member 15 and the second crank arm member 16 in contact with each other. An internal space S1 is formed. In this state, the first crank arm member 15 and the second crank arm member 16 are joined by diffusion bonding a portion T1 (contact portion) where the first crank arm member 15 and the second crank arm member 16 abut. Are joined.

  As shown in FIGS. 4 to 6, the left crank 13 includes a third crank arm member 17 (an example of a second member) and a fourth crank arm member 18 (an example of a first member). The third crank arm member 17 and the fourth crank arm member 18 are disposed to face each other. Further, an internal space S <b> 2 is formed between the third crank arm member 17 and the fourth crank arm member 18. In this state, the third crank arm member 17 and the fourth crank arm member 18 are joined by diffusion joining.

  Here, the third crank arm member 17 is made of a metal such as an iron alloy (an example of the second material), for example. The fourth crank arm member 18 is made of a metal (an example of a first material) such as an aluminum alloy, for example. Instead, the third crank arm member 17 and the fourth crank arm member 18 may be made of the same kind of metal material such as an aluminum alloy. In this case, the joining line between the first crank arm member 15 and the second crank arm member 16 is further inconspicuous while ensuring sufficient joining strength. That is, the appearance can be improved.

  Specifically, the third crank arm member 17 extends in the radial direction with respect to the crankshaft 11. The third crank arm member 17 includes a plate portion 17a, a crankshaft fixing portion 17b, and a pedal shaft fixing portion 17c.

  The crankshaft fixing portion 17b is formed integrally with the plate portion 17a on the base end side of the plate portion 17a. The crankshaft fixing portion 17b includes a first flange portion 17e and a crankshaft fixing hole 17d. The first flange portion 17e is formed on the outer peripheral portion of the crankshaft fixing portion 17b. The first flange portion 17e is formed continuously from the plate portion 17a. The crankshaft fixing hole 17d is for fixing the other end of the crankshaft 11. A spline groove is formed in the crankshaft fixing hole 17d.

  The fixed portion 17c for the pedal shaft is formed integrally with the plate portion 17a on the distal end side of the plate portion 17a. The pedal shaft fixing portion 17c includes a second flange portion 17f and a pedal mounting hole 17g. The second flange portion 17f is formed on the outer peripheral portion of the pedal shaft fixing portion 17c. The second flange portion 17f is formed continuously from the plate portion 17a. The pedal mounting hole 17g is for mounting a pedal shaft.

  The fourth crank arm member 18 extends in the radial direction with respect to the crankshaft 11. The fourth crank arm member 18 is disposed to face the third crank arm member 17. The fourth crank arm member 18 includes a fourth bottom portion 18a (an example of a first base portion) and a fourth edge portion 18b (an example of a first side surface portion and a second side surface portion).

  The fourth bottom portion 18 a is disposed to face the third crank arm member 17. The fourth bottom portion 18a contacts the pedal shaft fixing portion 17c of the third crank arm member 17 on the distal end side. The fourth bottom portion 18a abuts on the crankshaft fixing portion 17b of the third crank arm member 17 on the base end side. The fourth bottom portion 18a is disposed at a central portion with a distance from the plate portion 17a of the third crank arm member 17.

  The 4th edge part 18b is a part extended in the thickness direction of the 4th bottom part 18a from the outer edge part of the 4th bottom part 18a. The fourth edge portion 18b contacts the plate portion 17a of the third crank arm member 17 and the first flange portion 17e and the second flange portion 17f of the third crank arm member 17. Specifically, the fourth edge portion 18b abuts against the first flange portion 17e and the second flange portion 17f of the third crank arm member 17 on the distal end side and the proximal end side. Further, the fourth edge portion 18b is in contact with the outer edge portion of the plate portion 17a of the third crank arm member 17 at the center portion.

  In this way, an internal space S2 is formed at the center of the third crank arm member 17 and the fourth crank arm member 18. The fourth bottom portion 18a is in contact with the pedal shaft fixing portion 17c and the crankshaft fixing portion 17b of the third crank arm member 17 on the proximal end side and the distal end side. For this reason, no internal space is formed for this portion.

  Further, a through hole 18c is formed in the fourth bottom portion 18a on the base end side. The through hole 18 c is disposed concentrically with the crankshaft fixing hole 17 d of the third crank arm member 17. Further, a through hole 18d for inserting the pedal shaft is formed in the fourth bottom portion 18a on the distal end side. The through hole 18d is arranged concentrically with the pedal mounting hole of the third crank arm.

  In the left crank 13 having the above configuration, the third crank arm member 17 and the fourth crank arm member 18 are in contact with each other between the third crank arm member 17 and the fourth crank arm member 18 as described above. An internal space S2 is formed. In this state, the third crank arm member 17 and the fourth crank arm member 18 are joined by diffusion bonding at a portion T2 (contact portion) where the third crank arm member 17 and the fourth crank arm member 18 abut. Be joined.

  As shown in FIG. 7, one end of the crankshaft 11 is fixed to the right crank 12. Specifically, one end of the crankshaft 11 is spline-fitted into the crankshaft fixing hole 35h of the first crank arm member 15 from the upper side in FIG. 3A. The other end of the crankshaft 11 is fixed to the left crank 13. The other end of the crankshaft 11 is spline-fitted into a crankshaft fixing hole 17 d of the third crank arm member 17 shown in FIG. 4 and fixed by an axle bolt 19.

  The crankshaft 11 includes a first outer tubular member 28 (an example of a first shaft member) and a first inner member 29 (an example of a second shaft member). Here, the first outer tubular member 28 is made of a metal (an example of the first material) such as an aluminum alloy, for example. The first inner member 29 is made of, for example, a metal such as an iron alloy (an example of a second material).

  The first outer tubular member 28 is rotatably supported by a bottom bracket structure 33 provided on the hanger portion of the bicycle frame. The first outer tubular member 28 is formed in a hollow tubular shape.

  First and second spline teeth (not shown) are formed at both ends of the first outer tubular member 28. For example, one end of the crankshaft 11 is fixed to the right crank 12 by press-fitting the first spline teeth into the spline groove of the crankshaft fixing hole 35 h in the first crank arm member 15. Further, the second spline teeth are fitted into the spline groove in the crankshaft fixing hole 17d of the third crank arm member 17, and the axle bolt 19 is screwed into the inner peripheral portion of the first inner member 29, whereby the crankshaft The other end of 11 is fixed to the left crank 13.

  The first inner member 29 is formed in a hollow tubular shape. The first inner member 29 is disposed inside the first outer tubular member 28. Specifically, the first inner member 29 is disposed inside the first outer tubular member 28 in a state where the outer peripheral surface of the first inner member 29 is in contact with the inner peripheral surface of the first outer tubular member 28. The

  In the crankshaft 11 having the above configuration, a first outer tubular member is formed by diffusion bonding a portion T3 (abutting portion) where the outer peripheral surface of the first inner member 29 and the inner peripheral surface of the first outer tubular member 28 are in contact with each other. The member 28 and the first inner member 29 are joined.

  As described above, in the crank assembly 10, two members are joined by diffusion joining. Here, the first crank arm member 15 and the second crank arm member 16, the third crank arm member 17 and the fourth crank arm member 18, the first outer tubular member 28 and the first inner member 29 are two members. It corresponds to. An example of diffusion bonding will be described below.

  In diffusion bonding, first, two members are brought into close contact with each other. Next, pressurization is performed so as not to cause plastic deformation as much as possible under a temperature condition equal to or lower than the melting point of these two members. This causes atomic diffusion between the joints of the two members, thereby joining the two members together. Note that the insert metal may be melted between the joints of the two members.

  By performing diffusion bonding of the two members in this way, it is difficult for positional displacement at the time of bonding to occur, and the amount of deformation at the time of bonding is small. Thereby, in diffusion bonding, dimensional accuracy can be improved as compared with other bonding methods. Further, the two members can be surface bonded or laminated. Further, even if the two members are made of different materials such as different metals, these two members can be joined to each other. Furthermore, the finish, that is, the appearance of the joint between the two members can be improved as compared with other joining methods.

  In addition, also in the following structures, the example in case two members are joined by diffusion joining is shown. The description of the diffusion bonding is applied mutatis mutandis also in the following configurations.

[Rear sprocket assembly]
As shown in FIGS. 1, 8, and 9, the rear sprocket assembly 20 includes, for example, a first rear sprocket assembly 21 (an example of a rear sprocket assembly) and a second rear sprocket assembly (not shown). ,It is configured. First rear sprocket assembly 21 and the second rear sprocket assembly is mounted to a not-shown rear hub.

  As shown in FIGS. 8 and 9, the first rear sprocket assembly 21 includes two sprocket body portions 22 and 23 (sprocket body portion, an example of the second material) and a sprocket support portion 24 (sprocket support portion, An example of a first material). The two sprocket body portions 22 and 23 are supported by one sprocket support portion 24.

  Specifically, the sprocket body portions 22 and 23 are formed substantially in an annular shape. Sprocket teeth 22 a and 23 a are provided on the outer peripheral side of the sprocket main body portions 22 and 23. On the inner peripheral side of the sprocket body portions 22 and 23, first mounting portions 22b and 23b to be mounted on the sprocket support portion 24 are provided. Here, a plurality of (for example, six) first mounting portions 22 b and 23 b are provided on the inner peripheral side of the sprocket main body portions 22 and 23. The first mounting portions 22b and 23b are formed so as to protrude from the sprocket body portions 22 and 23 toward the inner peripheral side.

  The sprocket support portion 24 engages with a free wheel of a rear hub (not shown) and supports the sprocket body portions 22 and 23. The sprocket support portion 24 has a base portion 24a and a plurality of arm portions 24b. On the inner peripheral side of the base portion 24a, an engaging portion 24c that engages with the free wheel so as to rotate integrally is provided. A plurality of (for example, six) arm portions 24b are provided on the outer peripheral side of the base portion 24a.

  Specifically, each of the plurality of arm portions 24b extends radially outward from the base portion 24a and is formed at intervals in the circumferential direction. At the tip of the arm portion 24b, a mounted portion 24d to which the sprocket body portion is mounted is provided. The first mounting portions 22b and 23b of the sprocket body portions 22 and 23 are in contact with both surfaces of the mounted portion 24d. In this state, the sprocket body portions 22 and 23 and the sprocket support portion 24 are joined by diffusion joining the portion T4 (contact portion) where the first mounting portions 22b and 23b abut on the mounted portion 24d. . In FIG. 8, the contact portion T4 is hatched.

  The second rear sprocket assembly (not shown) includes a plurality of rear sprockets. Sprocket teeth are also provided on the outer peripheral side of the other plurality of rear sprockets. A spacer ring (not shown) is disposed between two adjacent rear sprockets in the other plurality of rear sprockets. Each rear sprocket and each spacer ring are mounted directly on the freewheel of the rear hub.

  The sprocket body portions 22 and 23 are made of a material such as an iron alloy or a titanium alloy, and the sprocket support portion 24 is made of a material such as an iron alloy or an aluminum alloy, for example.

[Front hub assembly and rear hub assembly]
As shown in FIGS. 1 and 10, the front hub assembly 30 is supported by a front fork 98. The front hub assembly 30 mainly includes a front hub shaft 34, a hub shell 37, a set of bearing assemblies 38, and a wheel fixing structure 39.

  The front hub assembly 30 is the same as the conventional configuration except for the front hub shaft 34. Therefore, here, the front hub shaft 34 will be described, and the description of the hub shell 90, the pair of bearing assemblies 92, and the quick release structure 94 will be omitted.

  Both end portions of the front hub shaft 34 are supported by a front fork 98 and fixed by a wheel fixing structure 39. The front hub shaft 34 is configured substantially in the same manner as the crankshaft 11.

  Specifically, the front hub shaft 34 includes a second outer tubular member 34a (an example of a first shaft member) and a second inner member 34b (an example of a second shaft member). The second outer tubular member 34a is formed in a hollow tubular shape. The second outer tubular member 34a is made of a metal (an example of a first material) such as an iron alloy, for example.

  The second inner member 34b is formed in a hollow tubular shape. The second inner member 34b is made of, for example, a metal such as an aluminum alloy (an example of a second material). The second inner member 34b is disposed inside the second outer tubular member 34a. Specifically, the second inner member 34b is disposed inside the second outer tubular member 34a in a state where the outer peripheral surface of the second inner member 34b is in contact with the inner peripheral surface of the second outer tubular member 34a. The

  In the front hub shaft 34 having the above-described configuration, the second outer side is formed by diffusion bonding a portion T5 (contact portion) where the outer peripheral surface of the second inner member 34b and the inner peripheral surface of the second outer tubular member 34a are in contact. The tubular member 34a and the second inner member 34b are joined.

  The rear hub assembly 40 shown in FIG. 1 is the same as the conventional configuration except for the rear hub shaft 41. Therefore, here, the rear hub shaft 41 will be described, and description of the other components will be omitted. Since the rear hub shaft 41 is substantially the same hub shaft as the front hub shaft 34, the rear hub shaft 41 will be briefly described.

  As shown in FIG. 11, the rear hub shaft 41 includes a third outer tubular member 41a (an example of a first shaft member) and a third inner member 41b (an example of a second shaft member). The hollow third outer tubular member 41a is made of, for example, a metal (an example of the second material) such as an iron alloy. The hollow third inner member 41b is made of, for example, a metal (an example of a first material) such as an aluminum alloy. The third inner member 41b is disposed inside the third outer tubular member 41a in a state where the outer peripheral surface of the third inner member 41b is in contact with the inner peripheral surface of the third outer tubular member 41a.

  In the rear hub shaft 41 having the above-described configuration, a third outer tubular member is formed by diffusion bonding a portion T6 (contact portion) where the outer peripheral surface of the third inner member 41b and the inner peripheral surface of the third outer tubular member 41a are in contact. The member 41a and the third inner member 41b are joined.

[Brake lever]
As shown in FIG. 1, each of the pair of brake levers 110 is swingably attached to a lever bracket 125 attached to the handle. By operating each of these brake levers 110, the front and rear brake devices 108 and 109 are operated. In FIG. 1, only one brake lever 110 is shown. Further, the brake devices 108 and 109 are the same as the conventional configuration, and thus the description thereof is omitted here.

  As shown in FIGS. 12 and 13, each brake lever 110 includes a first lever portion 111 (an example of a first lever portion) and a second lever portion 112 (an example of a second lever portion). The second lever portion 112 is disposed to face the first lever portion 111. Specifically, in a state where the second lever portion 112 is in contact with the first lever portion 111, the first lever portion 111 and the second lever portion 112 are joined by diffusion bonding.

  Here, the 1st lever part 111 is comprised from metals (an example of 1st material), such as an aluminum alloy, for example. The 2nd lever part 112 is comprised, for example from metals, such as an iron alloy (an example of 2nd material).

Specifically, the first lever portion 111 includes a second attachment portion 111a that is swingably attached to the lever bracket 125 shown in FIG. 1, and an operation portion 111b for operating the lever. A first lever mounting hole 111c is formed in the second mounting portion 111a. The operation part 111b has a fifth bottom part 111d extending in a direction away from the second mounting part 111a, and a fifth edge part 111e extending from the outer edge part of the fifth bottom part 111d in the thickness direction of the fifth bottom part 111d.

  The second lever portion 112 abuts on the first lever portion 111 in the range from the second mounting portion 111 a to the center portion of the first lever portion 111. Specifically, the second lever portion 112 has a pair of third mounting portions 112a and a reinforcing portion 112b. One of the pair of third mounting portions 112a can contact the second mounting portion 111a. The other of the pair of third mounting portions 112a is disposed to face the second mounting portion 111a with a predetermined interval from one of the pair of third mounting portions 112a. A second lever mounting hole 112c is formed in each of the pair of third mounting portions 112a. The pair of second lever mounting holes 112c are formed in the third mounting portion 112a so as to be substantially concentric with the first lever mounting holes 111c.

  The reinforcement part 112b is for reinforcing the operation part 111b. The reinforcing portion 112b preferably includes a facing portion 112d that faces the operation portion 111b, and a plurality of (for example, two) rib portions 112e that reinforce the operation portion 111b. The facing portion 112d abuts on the fifth bottom portion 111d of the operation portion 111b. The rib part 112e is provided in the opposing part 112d, and contact | abuts to a pair of 5th edge part 111e of the operation part 111b. One of the two rib portions 112e is provided at the end of the facing portion 112d, and abuts against the pair of fifth edge portions 111e at the central portion of the operation portion 111b.

  In the brake lever 110 having the above-described configuration, in the first lever portion 111 and the second lever portion 112, the second mounting portion 111a and one third mounting portion 112a, the fifth bottom portion 111d of the operation portion 111b, and the reinforcing portion 112b. The facing portion, the fifth edge portion 111e of the operation portion 111b, and the reinforcing portion 112b are in contact with each other. In this state, the first lever portion 111 and the second lever portion 112 are joined by the diffusion joining of the contact portion T7.

<Other embodiments>
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of invention. In particular, a plurality of embodiments and modifications described in this specification can be arbitrarily combined as necessary.

  (A) In the above embodiment, an example in which the first sprocket 31 constituting the sprocket assembly 50 does not have an internal space has been described. However, the first sprocket 31 may have an internal space.

  In this case, for example, as shown in FIG. 14A, the sprocket assembly 150 includes a first sprocket 131 and a second sprocket 132. The first sprocket 131 includes a front sprocket main body 131a, a front sprocket cover 131b, and a front sprocket sprocket tooth 131c.

  The front sprocket cover 131b is a portion that covers the front sprocket body 131a. The front sprocket cover 131b is made of, for example, an aluminum alloy (an example of the first material).

  The sprocket teeth 131c for the front sprocket are disposed between the front sprocket body 131a and the cover portion 131b for the front sprocket. The sprocket teeth 131c for the front sprocket are supported by a support portion 130 provided between the front sprocket body 131a and the front sprocket cover portion 131b. Here, the plurality of support portions 130 are arranged at intervals in the circumferential direction, and support the sprocket teeth 131c for the front sprocket. The support part 130 is provided in the outer peripheral part of the cover part 131b for front sprockets, for example.

  The front sprocket body 131a is disposed to face the front sprocket cover 131b. The front sprocket body 131a is made of, for example, an iron alloy (an example of a second material).

  Specifically, as shown in FIGS. 14A and 14B, the front sprocket body 131a includes a base body 231a and a cover support 231b. The base portion 231a is formed in a substantially annular shape. The base portion 231a is disposed to face the front sprocket cover portion 131b. The cover support portion 231b is formed integrally with the base portion 231a. Here, the plurality of cover support portions 231b are provided on the base portion 231a at intervals in the circumferential direction. Each cover support part 231b contacts the cover part 131b for the front sprocket.

  As a result, an internal space S3 is formed between the base portion 231a and the front sprocket cover portion 131b. In detail, between the cover support portions 231b adjacent to each other in the circumferential direction, between the base portion 231a and the front sprocket cover portion 131b, and between the sprocket teeth 131c for the front sprocket and the sprocket mounting portion 35, A space S3 is formed.

  In this state, the front sprocket body 131a and the front sprocket cover 131b are joined by diffusion joining the portion T8 (contact portion) where the cover support portion 231b and the front sprocket cover 131b abut. Is done. In FIG. 14B, only the rib-like contact portion T8 (portion corresponding to FIG. 14A) in the cover support portion 231b is assigned a reference numeral.

  Further, the sprocket teeth 131c for the front sprocket are diffusion-bonded to the outer peripheral portion of the front sprocket main body 131a (base portion 231a) and the portion T9 (contact portion) that contacts the outer peripheral portion of the cover portion 131b for the front sprocket. Thus, the sprocket teeth 131c for the front sprocket are joined to the front sprocket main body 131a and the cover portion 131b for the front sprocket. By configuring in this way, it is possible to obtain the same effect as in the above embodiment.

  (B) Although the first crank arm member 15 and the second crank arm member 16 are integrally formed in the right crank 12 in the above-described embodiment, the first crank arm member 15 and the first crank arm member 15 At least one of the two crank arm members 16 may be composed of a plurality of members.

Here, the right crank 113 is described as an example, but the third crank arm member 17 and the fourth crank arm member 18 in the left crank 13 of the above embodiment are also configured in the same manner as the right crank 113 shown here. May be.

The description of the right crank 113 described here is a description of parts different from the above-described embodiment, and the description omitted here is based on the above-described embodiment.
As shown in FIG. 15A, the right crank 113 includes a fifth crank arm member 115 and a sixth crank arm member 116.

  Since the fifth crank arm member 115 has the same configuration as the first crank arm member 15 of the above-described embodiment, the description thereof is omitted here. About the structure which abbreviate | omitted description here, it applies to description of the said embodiment.

  The sixth crank arm member 116 includes a first cover portion 136 (an example of a first member) and a third arm portion 126 (an example of a second member).

  The material constituting each of the first cover part 136 and the third arm part 126 includes, for example, any one of iron, aluminum, and titanium. Here, each of the 1st cover part 136 and the 3rd arm part 126 is comprised, for example from metals, such as an aluminum alloy. Instead of this, each of the first cover portion 136 and the third arm portion 126 may be made of a metal such as an iron alloy or a metal such as a titanium alloy, for example.

  Here, an example in which the first cover portion 136 and the third arm portion 126 are made of the same kind of metal material has been shown, but either one of the materials of the first cover portion 136 and the third arm portion 126 ( An example of the first material may be different from the other material (an example of the second material) of the first cover part 136 and the third arm part 126. In this case, under the condition that the material of each member is different, the material of each member includes, for example, any one of iron, aluminum, and titanium.

  Below, the structure of the 1st cover part 136 and the structure of the 3rd arm part 126 are demonstrated.

  The 1st cover part 136 is a part which covers the sprocket attaching part 35 shown to the said embodiment. The first cover part 136 is formed by forging. The 1st cover part 136 has the 1st junction part 136a. The first joint portion 136a is formed on the third arm portion 126 side.

  The third arm portion 126 is a portion that covers the first arm portion 25 shown in the embodiment. The third arm portion 126 is formed by a process different from forging. For example, the third arm portion 126 is formed by bending. More specifically, the third arm portion 126 is formed by bending a plate-like member. The third arm portion 126 has a second joint portion 126a. The second joint portion 126a is formed on the first cover portion 136 side. As shown in FIG. 15B, the second bonding portion 126a is preferably formed in a stepped shape. The first joint portion 136a of the first cover portion 136 abuts on the step-shaped second joint portion 126a. In FIG. 15A and FIG. 15B, the part (contact part) which the 1st junction part 136a contact | abuts to the 2nd junction part 126a is shown with the code | symbol T10. Thus, by forming the second joint portion 126a of the third arm portion 126 in a step shape, the joint area of the first cover portion 136 with the first joint portion 136a can be increased. Instead of forming the second joint portion 126a of the third arm portion 126 in a step shape, the first joint portion 136a of the first cover portion 136a may be formed in a step shape.

  The 1st cover part 136 and the 3rd arm part 126 which have said structure are joined by diffusion bonding. Specifically, in a state where the first joint portion 136a of the first cover portion 136 and the second joint portion 126a of the third arm portion 126 are in contact with each other, the first joint portion 136a and the second joint portion 126a are diffused. Joined by joining. Thereby, the sixth crank arm member 116 (the first cover portion 136 and the third arm portion 126) functions as one member. By configuring in this way, it is possible to obtain the same effect as in the above embodiment.

  The fifth crank arm member 115 and the sixth crank arm member 116 are diffusion-bonded in the same manner as in the above embodiment.

  (C) In the other embodiment (b), an example in which the sixth crank arm member 116 (the first cover portion 136 and the third arm portion 126) functions as one member by diffusion bonding is shown. . In addition, the fifth crank arm member 115 may also function as one member by diffusion bonding.

The description of the fifth crank arm member 215 (right crank 213 ) described here is a description of parts different from the above embodiment, and the description omitted here is in accordance with the above embodiment.

  For example, as shown in FIG. 16A, the fifth crank arm member 115 includes a sprocket mounting portion 235 (an example of a first member), a fourth arm portion 225 (an example of a second member), and a pedal shaft mounting portion 245 ( An example of a third member).

  The material constituting each of the sprocket attachment portion 235, the fourth arm portion 225, and the pedal shaft attachment portion 245 includes, for example, any one of iron, aluminum, and titanium. Here, each of the sprocket mounting portion 235, the fourth arm portion 225, and the pedal shaft mounting portion 245 is made of a metal such as an iron alloy, for example. Instead of this, each of the sprocket mounting portion 235, the fourth arm portion 225, and the pedal shaft mounting portion 245 may be made of, for example, a metal such as an aluminum alloy or a metal such as a titanium alloy.

  Here, an example in which each of the sprocket mounting portion 235, the fourth arm portion 225, and the pedal shaft mounting portion 245 is made of the same kind of metal material has been shown, but the sprocket mounting portion 235, the fourth arm portion 225, And two or all of the pedal shaft attachments 245 may be of different materials. In this case, under the condition that the material of each member is different, the material of each member includes, for example, any one of iron, aluminum, and titanium.

  Below, each structure of the sprocket attachment part 235, the 4th arm part 225, and the pedal shaft attachment part 245 is demonstrated.

The crankshaft 11 (see FIG. 2) can be attached to the sprocket attachment portion 235. For example, the sprocket mounting portion 235 has a crankshaft mounting hole 235h (an example of a first shaft mounting portion), and the crankshaft 11 can be mounted in the crankshaft mounting hole 235h. More specifically, one end of the crankshaft 11 is press-fitted into the crankshaft mounting hole 235 h .
The sprocket mounting portion 235 is disposed to face the first cover portion 136 (see FIG. 15A). The sprocket mounting portion 235 is formed by forging. The sprocket mounting portion 235 has a third joint portion 235a. The third joint portion 235a is formed on the fourth arm portion 225 side.

  The fourth arm portion 225 is a portion that connects the sprocket attachment portion 235 and the pedal shaft attachment portion 245. The fourth arm portion 225 is disposed to face the third arm portion 126 (see FIG. 15A). The fourth arm portion 225 is formed by a process different from forging. For example, the fourth arm portion 225 is formed by bending. More specifically, the 4th arm part 225 is shape | molded by bending a plate-shaped member.

  The fourth arm portion 225 includes a fourth joint portion 225a and a fifth joint portion 225b. The fourth joint portion 225a is formed on the sprocket attachment portion 235 side. The fifth joint portion 225b is formed on the pedal shaft attachment portion 245 side. Each of the fourth joint portion 225a and the fifth joint portion 225b is formed in a step shape (see FIG. 16B). The third joint portion 235a of the sprocket mounting portion 235 comes into contact with the step-like fourth joint portion 225a. A sixth joint portion 245a of a pedal shaft attachment portion 245 described later contacts the step-like fifth joint portion 225b. In this way, by forming the fourth joint portion 225a and the fifth joint portion 225b of the fourth arm portion 225 in a stepped shape, the third joint portion 235a of the sprocket attachment portion 235 and the sixth of the pedal shaft attachment portion 245 are formed. The joint area with the joint portion 245a can be increased. Instead of forming the fourth joint portion 225a and the fifth joint portion 225b of the fourth arm portion 225 in a stepped shape, the third joint portion 235a of the sprocket attachment portion 235 and the sixth joint portion of the pedal shaft attachment portion 245 245a may be formed in a step shape.

  In FIG. 16A and FIG. 16B, a portion (contact portion) where the third joint portion 235a abuts on the fourth joint portion 225a is denoted by reference numeral T11. A portion (contact portion) where the sixth joint portion 245a abuts on the fifth joint portion 225b is denoted by reference numeral T12.

  A pedal shaft (not shown) can be attached to the pedal shaft mounting portion 245. For example, the pedal shaft mounting portion 245 has a pedal mounting hole 245b (an example of a second shaft mounting portion). A pedal shaft can be attached to the pedal mounting hole 245b. More specifically, one end of the pedal shaft is screwed into the pedal mounting hole 245b.

The pedal shaft attachment portion 245 is disposed to face the third arm portion 126 (see FIG. 15A). The pedal shaft mounting portion 245 is formed by forging. The pedal shaft attachment portion 245 has a sixth junction 245a. Sixth junction 245a is formed in the fourth arm portion 225 side. The sixth joint 245a contacts the step-like fifth joint 225b.

  The sprocket attachment portion 235, the fourth arm portion 225, and the pedal shaft attachment portion 245 having the above configuration are joined by diffusion bonding. Specifically, the third joint portion 235a of the sprocket attachment portion 235 is joined to the fourth joint portion 225a of the fourth arm portion 225 by diffusion joining. Further, the sixth joint portion 245a of the pedal shaft attachment portion 245 is joined to the fifth joint portion 225b of the fourth arm portion 225 by diffusion joining. Accordingly, the fifth crank arm member 115 (sprocket mounting portion 235, fourth arm portion 225, and pedal shaft mounting portion 245) functions as one member. By configuring in this way, it is possible to obtain the same effect as in the above embodiment.

  Also in this case, the fifth crank arm member 115 and the sixth crank arm member 116 are diffusion-bonded in the same form as in the above embodiment.

(D) In the other embodiment (c), an example in which the sprocket attachment portion 235, the fourth arm portion 225, and the pedal shaft attachment portion 245 are joined by diffusion bonding has been described. Instead of this, any one of the sprocket mounting portion 235 and the pedal shaft mounting portion 245 may be formed integrally with the fourth arm portion 225. In this case, either the sprocket mounting portion 235 or the pedal shaft mounting portion 245 and the fourth arm portion 225 are diffusion bonded. In this configuration, the other of the sprocket mounting portion 235 and the pedal shaft mounting portion 245 corresponds to an example of the first member, and the fourth arm portion 225 (either the sprocket mounting portion 235 or the pedal shaft mounting portion 245). (Including one) corresponds to an example of the second member. Even if comprised in this way, the effect similar to the said embodiment can be acquired.

  (E) In the other embodiment (d), an example has been shown in which both the fifth crank arm member 215 and the sixth crank arm member 116 function as one member by diffusion bonding. Instead, the fifth crank arm member 215 is configured in accordance with the other embodiment (d), and the sixth crank arm member 116 is configured in the same manner as in the embodiment shown in FIGS. 1 to 14B. Also good. Even if comprised in this way, the effect similar to the said embodiment can be acquired.

  (F) In the above embodiment, the crank assembly 10, the rear sprocket assembly 20, the front hub assembly 30, the rear hub assembly 40, the brake lever 110, and the sprocket assembly 50, which are bicycle parts, are Although an example in which the invention is applied is shown, the present invention is not limited to this. That is, the present invention can be applied to other bicycle parts. For example, the present invention can be applied to a front derailleur, a rear derailleur, a shift lever, and the like. More specifically, the present invention can be applied to a chain guide for a front derailleur, a chain guide for a rear derailleur, and the like.

  (G) In the above-described embodiment, an example in which the first sprocket 31 and the second sprocket 32 are fixed to the sprocket mounting portion 35 by the fixing bolt 35g is shown. However, the first sprocket 31 and the second sprocket 32 are The sprocket attachment portion 35 may be joined by diffusion joining. In this case, the first sprocket 31 and the second sprocket 32 can be diffusion bonded to the sprocket mounting portion 35 in the same manner as the diffusion bonding shown in the first rear sprocket assembly 21 of the above embodiment.

  (H) In the above embodiment, an example in which the internal spaces S1, S2, and S3 are hollow has been described. However, a filler such as a foam member may be disposed in the internal spaces S1, S2, and S3.

  (I) In the above-described embodiment, an example in which a plurality of bicycle parts are diffusion bonded is shown. However, not all the above bicycle parts are diffusion bonded, but at least one bicycle part is diffusion bonded. It may be.

DESCRIPTION OF SYMBOLS 10 Crank assembly 11 Crankshaft 15, 16, 17, 18 1st-4th crank arm member 20 Rear sprocket assembly 22, 23 Sprocket main-body part 24 Sprocket support part 30 Front hub assembly 34 Front hub axis 40 Rear hub assembly 41 Rear hub shaft 50 Sprocket assembly 110 Brake lever 111 First lever portion 112 Second lever portion S1 to S3 Internal space T1 to T12 Contact portion

Claims (32)

A first member;
A second member disposed opposite the first member;
With
An internal space is formed between the first member and the second member,
The first member and the second member are joined by diffusion bonding.
Bicycle parts. Either one of the first member and the second member is composed of a first material,
Either one of the first member and the second member is composed of a second material different from the first material.
The bicycle part according to claim 1. The first material is an aluminum alloy;
The second material is an iron alloy.
The bicycle part according to claim 2. The first member and the second member are made of the same kind of metal material,
The bicycle part according to claim 1. The first member includes a first base portion, a first side surface portion extending from one end portion of the first base portion in the thickness direction of the first base portion, and the first end portion from the other end portion of the first base portion. A second side surface portion extending in the thickness direction of the base portion and facing the first side surface portion,
The second member is disposed to face the first base portion,
The first side surface portion, the second side surface portion, and the second member are bonded by the diffusion bonding,
The bicycle part according to claim 1. The second member is plate-shaped,
The bicycle part according to claim 5. The second member includes a second base portion, a third side surface portion extending from one end portion of the second base portion in the thickness direction of the second base portion, and the second side portion from the other end portion of the second base portion. A fourth side surface portion extending in the thickness direction of the base body portion and facing the third side surface portion,
The second base portion is disposed to face the first base portion,
Either one of the first side surface portion and the second side surface portion and one of the third side surface portion and the fourth side surface portion are joined by the diffusion bonding,
The other of the first side surface and the second side surface and the other of the third side surface and the fourth side surface are joined by the diffusion bonding.
The bicycle part according to claim 5. A crank arm is constituted by the first member and the second member.
The bicycle part according to any one of claims 1 to 7. A front sprocket assembly is constituted by the first member and the second member.
The bicycle part according to any one of claims 1 to 7. A hollow first shaft member;
A second shaft member disposed inside the first shaft member;
With
The first shaft member and the second shaft member are joined by diffusion bonding.
Bicycle shaft member. Either one of the first shaft member and the second shaft member is made of a first material,
Either one of the first shaft member and the second shaft member is composed of a second material different from the first material.
The bicycle shaft member according to claim 10. The first material is an aluminum alloy;
The second material is an iron alloy.
The bicycle shaft member according to claim 11. The second shaft member is a hollow member;
A crankshaft is constituted by the first shaft member and the second shaft member.
The bicycle shaft member according to claim 10. The second shaft member is a hollow member;
A hub shaft is constituted by the first shaft member and the second shaft member.
The bicycle shaft member according to claim 10. Sprocket body,
A sprocket support for supporting the sprocket body,
With
The sprocket body and the sprocket support are joined by diffusion bonding.
Bicycle rear sprocket assembly. Either one of the sprocket body and the sprocket support is composed of a first material,
The other of the sprocket body and the sprocket support is composed of a second material different from the first material.
The bicycle rear sprocket assembly according to claim 15. The first material is an aluminum alloy;
The second material is an iron alloy.
The bicycle rear sprocket assembly according to claim 16. A first lever portion;
A second lever portion disposed to face the first lever portion;
With
The first lever part and the second lever part are joined by diffusion joining.
Bicycle lever member. Either one of the first lever part and the second lever part is made of a first material,
Either one of the first lever part and the second lever part is composed of a second material different from the first material,
The bicycle lever member according to claim 18. The first material is an aluminum alloy;
The second material is an iron alloy.
The bicycle lever member according to claim 19. A first member formed by forging;
A second member;
With
The first member and the second member are joined by diffusion bonding;
Bicycle parts. The first member and the second member are made of the same material,
The bicycle part according to claim 21. The first member and the second member include any one of iron, aluminum, and titanium.
The bicycle part according to claim 22. Either one of the first member and the second member is composed of a first material,
Either one of the first member and the second member is composed of a second material different from the first material.
The bicycle part according to claim 21. The first material includes any one of iron, aluminum, and titanium,
The second material includes any one of iron, aluminum, and titanium.
The bicycle part according to claim 24. The second member is formed by a process different from the forging,
The bicycle part according to claim 21. The second member is formed by bending.
The bicycle part according to claim 26. The second member is a plate member and is molded by the processing.
The bicycle part according to claim 26 or 27. A third member molded by forging;
The bicycle component according to claim 21, further comprising: The first member has a first shaft mounting portion for mounting the first shaft member.
30. The bicycle part according to claim 29. The third member has a second shaft mounting portion for mounting the second shaft member.
The bicycle part according to claim 29 or 30. The first member, the second member, and the third member constitute a crank arm,
The first shaft attachment portion can attach a crankshaft,
The second shaft mounting portion can mount a pedal shaft.
The bicycle part according to any one of claims 29 to 31.

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