TWI777751B - Composite crank and method of making the same - Google Patents

Abstract

A composite crank, comprising a first metal piece, a second metal piece, an outer fiber piece, and a reinforcing fiber piece, the first metal piece and the second metal piece are arranged at intervals, and the outer fiber piece covers the The first metal piece, the second metal piece, the outer fiber piece, the first metal piece, and the second metal piece together define a socket space to form a space between the three, and the reinforcing fiber piece is disposed in the socket space , which has a rib wall and two abutting ends bent from opposite sides of the rib wall, and the two abutting sections are respectively attached to the outer fiber piece; the composite crank has the advantages of light weight and torsional load bearing .

Description

Composite crank and method of making the same

The present invention relates to a crank for bicycles, in particular to a crank made of composite materials.

Bicycle design usually uses a rigid structure frame to connect the front and rear wheels in series, and the crank is connected between the chain wheel and the pedal, and the force of the user's pedaling is transmitted to the rear wheel through the chain wheel and chain. As a structural component for power transmission, bicycle cranks are often made of steel or alloys. In order to ensure smooth pivoting at both the pedal and sprocket ends of the crank, the crank must have strong pivot connections at both ends to withstand the torsional loads from both the pedal and sprocket ends. In addition, in order to reduce the weight of the vehicle body, fiber materials are used in the manufacture of bicycle frames. However, fiber materials are not conducive to making pivot structures that can withstand high torque, so bicycle cranks are made of composite materials of metal and fiber.

The main purpose of the present invention is to provide a composite crank and a manufacturing method thereof. The composite crank has the advantages of light weight and can improve the structural strength in the thickness direction of the composite crank.

In order to achieve the above-mentioned purpose, the composite crank proposed by the present invention includes: a first metal piece; a second metal piece arranged at intervals from the first metal piece; an outer fiber piece covering the first metal piece and the second metal piece, the outer fiber piece, the first metal piece and the second metal piece together define a socket space formed between the three; and A reinforcing fiber piece is disposed in the socket space, the reinforcing fiber piece has a rib wall extending along a thickness direction and a length direction of the composite crank, and the reinforcing fiber piece is bent out of two opposite sides of the rib wall. A bonding section, the two bonding sections extend along the width direction and the length direction of the composite crank and are respectively bonded to the outer fiber piece.

Another composite crank proposed by the present invention includes: a first metal piece, having a first contact hole portion and a first connection section, the first connection section defines a first chamber and a first opening; A second metal piece arranged at intervals from the first metal piece, the second metal piece has a second contact hole portion and a second connecting section, the second connecting section defines a second chamber and a second opening ;as well as An outer fiber piece covering the first metal piece and the second metal piece arranged at intervals, so that the outer fiber piece, the first metal piece and the second metal piece together define a socket space formed in the aforementioned three pieces between, the socket space communicates with the first chamber and the second chamber; Wherein, the first connecting segment integrally extends from the first contact hole portion toward the second metal piece, and the second connecting segment integrally extends from the second contact hole portion toward the first metal piece; Wherein, the outer fiber piece integrally covers the first connecting hole portion, the first connecting section, the socket space, the second connecting section and the second connecting hole portion.

Another composite crank proposed by the present invention includes: a first metal piece, having a first contact hole portion and a first connection section, the first connection section defines a first chamber and a first opening; A second metal piece is arranged at intervals from the first metal piece, the second metal piece has a second contact hole portion and a second connection section, the second contact hole portion has a second contact hole, the second the connecting section defines a second chamber and a second opening; and An outer fiber piece wraps the first metal piece and the second metal piece, the outer fiber piece, the first metal piece, and the second metal piece together define a socket space formed between the three, the The socket space communicates with the first chamber of the first metal piece and the second chamber of the second metal piece; Wherein, the second metal piece includes a ring groove surrounding the outer circumference of the second contact hole, and is separated from the second contact hole by a hole wall, and the ring groove communicates with the second chamber.

Preferably, the first contact hole portion of the first metal piece has a first contact hole, and the depth of the first chamber in a length direction of the composite crank is greater than that of the first metal member in the first chamber. The thickness between the chamber and the first contact hole.

Preferably, the second contact hole portion of the second metal member has a second contact hole, and the depth of the second chamber in a length direction of the composite crank is greater than that of the second metal member in the second chamber. The thickness between the chamber and the second contact hole.

The manufacturing method of the composite crank proposed by the present invention comprises: providing a first metal piece, a second metal piece, and a core material; forming a reinforcing fiber piece on the core material, the reinforcing fiber piece passing through the core material; Inserting opposite ends of the core material with the reinforcing fiber member into a first chamber of the first metal member and a second chamber of the second metal member respectively; and overmolding the outer fiber piece on the surface of the first metal piece, the second metal piece and the core material and molding by hot pressing a mold, so that the outer fiber piece is combined with the reinforcing fiber piece; Wherein, the reinforcing fiber piece has a rib wall, the rib wall extends along a thickness direction and a length direction of the composite crank, and the reinforcing fiber piece is bent from two opposite sides of the rib wall to form two fitting sections, the two The bonding section extends along a width direction and a length direction of the composite crank and is respectively bonded to the outer fiber piece.

In the present invention, the weight of the composite crank is reduced by covering the first metal piece and the second metal piece with the outer fiber piece, and the rigidity in the thickness direction of the composite crank is improved by using the reinforcing fiber piece arranged in the socket space, so that the The composite crank of the invention has the advantages of light weight and enhanced structural strength in the thickness direction of the composite crank.

Please refer to FIG. 1, FIG. 2, FIG. 3A/3B and FIG. 4A/B, the first preferred embodiment of the composite crank 1 of the present invention is suitable for a bicycle. For the convenience of description, a long axis is defined in each drawing. X, a short axis Y, and a reference axis Z or the thickness direction of the composite crank 1, the long axis X and the short axis Y are respectively perpendicular to the reference axis Z or the thickness direction of the composite crank 1, and the short axis Y is perpendicular to the long axis X. For the convenience of description, each embodiment of the present invention takes a flat composite crank 1 as an example; in other embodiments of the present invention, the upper surface, the lower surface and the side surface of the composite crank 1, as well as all the elements and structures, may be along the Two or three directions of the reference axis Z, the long axis X and the short axis Y extend simultaneously, so that the composite crank 1 has curvature, twist or deflection, so a straight crank with a single thickness is not necessarily limited.

The composite crank 1 includes a first metal piece 10, a second metal piece 20, a socket space, an outer fiber piece 40, and one or more reinforcing fiber pieces 30/30a/30b. The composite crank 1 mainly extends along the long axis X, the first metal piece 10 and the second metal piece 20 are spaced apart and arranged at intervals, and a socket space S is defined between the first metal piece 10 and the second metal piece 20 , The outer fiber piece 40 is wrapped around the outer circumference of the first metal piece 10 , the second metal piece 20 and the socket space S, and the reinforcing fiber piece 30 penetrates the socket space S longitudinally and connects two opposite inner surfaces of the outer fiber piece 40 . The long axis X is also called the connection direction of the first metal piece 10 and the second metal piece 20 or the length direction of the compound crank 1, the short axis Y is called the width direction of the compound crank 1, and the reference axis Z is called the compound crank 1 in the thickness direction, the composite crank 1 of the present invention mainly enhances the structural strength of the reference axis Z direction or the thickness direction of the composite crank 1 .

The first metal piece 10 , for example, an aluminum piece, includes a first contact hole portion 11 and a first connecting section 13 . The first contact hole portion 11 has a wavy annular hole wall and defines a first contact hole 110 . A connecting hole 110 extends along the Z direction of the reference axis or the thickness direction of the composite crank 1 , and the first connecting hole 11 is used for connecting with the tee or bottom bracket wheel hub where the lower tube, chainstay and/or seat tube of the bicycle meet. For connection, in this embodiment, the first contact hole 110 is a through hole, but the first contact hole 110 can also be set as a blind hole, or a combination of a partial through hole and a blind hole; the first connection section 13 is formed by the first contact hole portion 11 extends, for example, can extend along the long axis X direction, and a first opening 132 is formed at one end away from the first contact hole portion 11 , and the first connecting section 13 has a first width D1 extending along the short axis Y direction.

The second metal piece 20 and the first metal piece 10 are arranged at intervals to define the socket space S. The second metal piece 20 and the first metal piece 10 can be arranged at intervals along the long axis X direction, for example, the second metal piece 20 It can be an aluminum piece, the second metal piece 20 includes a second contact hole portion 21 and a second connection section 23 , the second contact hole portion 21 defines a second contact hole 210 , and the second contact hole 210 is along the reference axis Z The second contact hole 21 is used to connect with the pedals of the bicycle. In this embodiment, the second contact hole 210 is a through hole, and the second contact hole 210 can also be set as a Blind hole; the second connecting section 23 extends from the second contact hole portion 11 , for example, it can extend toward the first metal piece 10 along the long axis X direction, and is away from the second contact hole portion 21 and the end adjacent to the first metal piece 10 A second opening 232 is formed, and the second connecting segment 23 has a second width D2 extending along the Y direction of the short axis.

The socket space S is formed in the composite crank 1, located between the first metal piece 10 and the second metal piece 20, and communicated with the first opening 132 and the second opening 232; preferably, the first connecting section 13 It further includes a first accommodating chamber 131, the first accommodating chamber 131 is formed in the first connecting section 13 and communicates with the first opening 132, and a first connecting peripheral wall 133 is formed around the outer periphery of the first accommodating chamber 131. The chamber 131 communicates with the socket space S through the first opening 132. As shown in FIG. 2, the depth L1 of the first chamber 131 in the longitudinal direction of the composite crank 1 is greater than that of the first metal piece 10 in the first chamber. The thickness T1 between the chamber 131 and the first connecting hole 110 ; the second connecting section 23 further includes a second chamber 231 , the second chamber 231 is formed in the second connecting section 23 and communicates with the second opening 232 , and a second connecting peripheral wall 233 is formed around the outer periphery of the second chamber 231. The second chamber 231 is communicated with the socket space S through the second opening 232. As shown in FIG. 2, the second chamber 231 is in the compound crank. The depth L2 in the longitudinal direction of 1 is greater than the thickness T2 of the second metal piece 20 between the second chamber 231 and the second contact hole 210 .

The outer fiber member 40 can be a resin prepreg made of carbon fiber, glass fiber or other fiber material (fiber sheet), which is wrapped around the first metal member 10, the second metal member 20, and the entire outer periphery of the socket space S . The reinforcing fiber pieces 30/30a/30b shown in FIGS. 3A/3B and 4A/4B can be resin prepregs made of carbon fiber, glass fiber or other fiber material (fiber sheet), and one or more reinforcing fiber pieces 30/30/ 30a/30b are both disposed between the first metal piece 10 and the second metal piece 20, and the reinforcing fiber piece 30/30a/30b includes two fitting sections 33/33a/33b and a rib wall 31/31a/31b. The joint sections 33/33a/33b are respectively attached to the two opposite inner surfaces of the outer fiber member 40 along the reference axis Z direction or the thickness direction of the composite crank 1, and the rib walls 31/31a/31b are arranged in the socket space S and connect the two stickers. Combined segments 33/33a/33b. In different embodiments, the reinforcing fiber piece 30/30a/30b, its two adhering sections 33/33a/33b and the rib wall 31/31a/31b are substantially along the distance between the first metal piece 10 and the second metal piece 20 The straight line (such as the straight composite crank 1 in the previous figure) or the direction of the curved line (such as the composite crank 1 with curvature) extends, and the two fitting sections 33/33a/33b extend from the rib walls 31/31a/31b After being bent, it is attached to the two opposite inner side surfaces of the outer fiber member 40 along the thickness direction of the composite crank 1 .

Preferably, the rib wall 31/31a/31b of the reinforcing fiber member 30/30a/30b is along the long axis X (or the direction of the connection between the first metal member 10 and the second metal member 20) and the reference axis Z (or The thickness direction of the composite crank 1) extends, and the two bonding sections 33/33a/33b extend along the long axis X; in this embodiment, the longitudinal ends of the reinforcing fiber piece 30/30a/30b are respectively connected to the first metal piece 10. and adjacent to the second metal piece 20 .

In this embodiment, the two adhering sections 33/33a/33b of the reinforcing fiber pieces 30/30a/30b extend from the rib walls 31/31a/31b in opposite directions along the short axis Y (the width direction of the composite crank 1 ), respectively , and form a zigzag shape (FIG. 4A/4B), the first width D1 of the first connecting section 13 of the first metal piece 10 is greater than the second width D2 of the second connecting section 23 of the second metal piece 20 (FIG. 3A/ 3B), and the width dimension of each bonding section 33/33a/33b of the reinforcing fiber piece 30/30a/30b adjacent to one end of the first metal piece 10 along the short axis Y (the width direction of the composite crank 1) is larger than that of the adjacent second metal piece The width dimension of one end of 20 along the short axis Y (the width direction of the composite crank 1 ) can improve the strength of the part of the composite crank 1 adjacent to the first metal piece 10 . In other embodiments, the fitting sections 33/33a/33b can also be set to a fixed width.

In FIG. 2, there are gaps G1/G2 between the two longitudinal ends of the reinforcing fiber piece 30 and the first connecting section 13 of the first metal piece 10 and the second connecting section 23 of the second metal piece 20, respectively. The outer fiber piece 40 forms a gap G1/G2. The two inner annular ribs 41a/41b are located at the gaps G1/G2, that is, the inner annular rib 41a is located between a longitudinal end of the reinforcing fiber member 30 and the first connecting section 13 of the first metal member 10, and the inner annular rib 41b is located at the reinforcing fiber member 30. between the other longitudinal end and the second connecting section 23 of the second metal piece 20 .

By using the outer fiber piece 40 to cover the first metal piece 10/second metal piece 20 with the hollow first connecting section 13/second connecting section 23, and the socket space S between the two, the composite crank can be lightened 1, and the reinforcing fiber pieces 30/30a/30b arranged in the socket space S are used to improve the structural strength of the composite crank 1 in the thickness direction, so that the composite crank 1 of the present invention has a light weight and can improve the composite crank 1. Advantages of the rigidity of the crank 1 in the thickness direction.

Please refer to FIG. 5 , FIG. 6 and FIG. 12 , the above-mentioned manufacturing method of the composite crank 1 includes the following steps. The following description is mainly based on the manufacturing method. For details of the structure or component features, please refer to the drawings and corresponding text descriptions of other embodiments; the component features or structures of other embodiments that are not directly mentioned in the following process are generally known in the art. Alternatively, the following process steps can be applied to realize the description in conjunction with the description of the features or structures of the components.

Step S1 : providing a first metal piece 10 , a second metal piece 20 , and a longitudinally extending core material 50 . For the convenience of description, the following takes the straight compound crank 1 as an example, so the long axis X, the short axis Y and the reference axis Z which are perpendicular to each other are taken as the direction reference. However, as mentioned above, in different embodiments, the composite crank 1 can have curvature, torsion or deflection, and variable thickness/width, so the long axis X should be replaced by the first metal piece 10 and the second metal piece 20 The direction of the straight line or curve connection between the two, the short axis Y should be replaced by the width direction of the composite crank 1, the reference axis Z should be replaced by the thickness direction of the composite crank 1, and the aforementioned connection direction, width direction and thickness direction. , are not absolutely necessary to be perpendicular to each other to accommodate composite cranks 1 with curvature, twist or deflection, varying thickness/width.

The first metal piece 10 can be an aluminum piece used to connect the bicycle bottom bracket, which includes a first contact hole portion 11 and a first connection section 13, and the first contact hole portion 11 defines a direction along a reference axis Z. A first contact hole 110 is extended, and the first connecting segment 13 extends from the first contact hole portion 11 along a long axis X direction, and a first opening 132 is formed at one end away from the first contact hole portion 11 , and the long axis X Perpendicular to the reference axis Z, a first chamber 131 communicating with the first opening 132 is formed in the first connecting section 13 .

The second metal piece 20 can be an aluminum piece used for connecting bicycle pedals, and includes a second connecting hole portion 21 and a second connecting section 23 . The second connecting hole portion 21 defines a A second contact hole 210 , the second connecting section 23 extends from the second contact hole portion 21 along the direction of the long axis X, and a second opening 232 is formed at one end away from the second contact hole portion 21 . A second chamber 231 communicating with the second opening 232 is formed.

The core material 50 can be a wax material or a foamed resin. The core material 50 made of the wax material is a wax core that can be taken out. The ends are respectively protruded with an insertion portion 53; the core material 50 is provided with a through slot 51 and two insert slots 52, the through slot 51 is a narrow and long through hole, and along the long axis X direction and the reference axis Z direction or the composite crank 1/core The two insert grooves 52 are respectively recessed on the surface of the core material 50 along the reference axis Z direction or the opposite side of the thickness direction of the composite crank 1/core material 50, and communicate with the through groove 51. The two insert grooves 52 respectively extend from the through-grooves 51 toward the direction along the short axis Y.

Step S2: forming a reinforcing fiber piece 30 on the core material 50, the reinforcing fiber piece 30 can use the resin prepreg of the aforementioned fiber sheet, and after passing through the groove 51 of the core material 50, the reinforcing fiber piece 30 is protruded from the core material The sections on the opposite sides of the 50 along the Z direction of the reference axis are respectively bent and attached to the opposite side surfaces of the core material 50 along the Z direction of the reference axis, and are respectively accommodated in the two insert grooves 52 of the core material 50 to allow the reinforcement The section of the fiber piece 30 passing through the core material 50 forms a rib wall 31 , and the sections that adhere to the opposite sides of the core material 50 along the reference axis Z direction form two adhering sections 33 .

Step S3: Insert the opposite ends of the core material 50 with the reinforcing fiber member 30 into the first opening 132 of the first metal member 10 and the second opening 232 of the second metal member 20, respectively. Insert the insertion parts 53 at opposite ends of the core material 50 along the long axis X direction into the first opening 132 of the first metal piece 10 and the second opening 232 of the second metal piece 20 respectively, so that the insertion parts 53 are inserted into the first opening 132 of the first metal piece 10 and the second opening 232 of the second metal piece 20 Inside the first chamber 131 of the metal member 10 and the second chamber 231 of the second metal member 20 , the outer surface of the core material 50 is flush with the outer surfaces of the first metal member 10 and the second metal member 20 , and The adhering section 33 of the reinforcing fiber piece 30 is flush with the outer surfaces of the opposite sides of the first metal piece 10 and the second metal piece 20 along the reference axis Z direction.

Step S4 : wrapping the outer fiber member 40 on the surfaces of the first metal member 10 , the second metal member 20 and the core material 50 and molding by hot pressing. The outer fiber piece 40 can use one or more resin prepregs of the aforementioned fiber sheets, and the outer fiber piece 40 is wrapped around the first metal piece 10 , the second metal piece 20 , the core material 50 and the reinforcing fiber piece 30 assembled After the outer surface of the semi-finished product is completed, the outer fiber piece 40 will cover the outer sides of the two adhering sections 33 of the reinforcing fiber piece 30, and then the semi-finished product covered with the outer fiber piece 40 will be put into the mold for hot pressing. During the compression molding process, the high temperature of the mold can be conducted from the outer fiber part 40 to the reinforcing fiber part 30, so that the fiber prepreg of the outer fiber part 40 and the fiber prepreg of the reinforcing fiber part 30 are cured and molded, and the outer fiber The component 40 , the first metal component 10 , the second metal component 20 , and the core material 50 are combined with the reinforcing fiber component 30 into one body.

Step S5 : if necessary, take out the core material 50 from the outer fiber member 40 . When the core material 50 is a wax core, the manufacturing method of the present invention further includes providing a wax hole, and the core material 50 is hot-melted out of the outer fiber member 40 . The method of taking out can firstly drill holes in the position of the outer fiber piece 40 corresponding to the core material 50, put the drilled crank into the oven to heat and melt the wax, and let the melted core material 50 flow out from the drilled hole, and allow it to flow out. The original space of the core material 50 forms a hollow socket space S, so that a hollow composite crank 1 with reinforcing ribs can be obtained. Since the molten wax only needs a small hole diameter to flow out, the relatively high structural strength can be maintained after the hole is filled, and there will be no residual material 50 of the core material in the composite crank 1, which will increase the weight or make a knocking sound. The drilling position is not limited to the region where the core material 50 is not inserted into the first metal piece 10 and the second metal piece 20 , and wax holes can also be reserved on the first metal piece 10 and/or the second metal piece 20 as required. When the core material 50 is a foamed material, since the core material 50 binds the shrinkage cuff to the reinforcing fiber member 30 during the hot pressing process, it does not cause unnecessary noise even though it does not need to be taken out.

Referring to FIG. 7 , in the second preferred embodiment of the present invention, the second contact hole portion 21 of the second metal member 20 includes a ring groove 24 , and the ring groove 24 surrounds the outer circumference of the second contact hole 210 and is connected to the second contact hole 210 . The holes 210 are separated by a hole wall 211, and the annular groove 24 communicates with the second chamber 231, which can further reduce the weight of the composite crank 1; The two sub-metal parts 201 and 202 in the thickness direction of On the outer periphery of 201 and 202, the convex part is protruded in the direction of the other sub-metal parts 201 and 202 along the reference axis Z or the thickness direction of the composite crank 1 in the sub-metal parts 201 and 202, and is connected with the other sub-metal parts 201 and 202. The convex parts of 202 are in contact with each other, and a sub-ring groove 241, 242 is formed between the convex part and the sub outer ring walls 221, 222, and each convex part is formed with a sub-joint extending along the reference axis Z or the thickness direction of the composite crank 1. holes 2101, 2102, and a sub-hole wall 2111, 2112 is formed on the outer periphery of the sub-connecting holes 2101, 2102, the sub-hole walls 2111, 2112 of the two sub-metal parts 201, 202 are abutted to form the hole wall of the second metal part 20 211. The sub-contact holes 2101 and 2102 of the two sub-metal pieces 201 and 202 are aligned with each other and communicate with each other to form the second contact hole 210 of the second metal piece 20. The sub-ring grooves 241 and 242 of the two sub-metal pieces 201 and 202 are connected to each other. An annular groove 24 is formed around the outer circumference of the hole wall 211 .

Referring to FIGS. 8 to 10 , in the third preferred embodiment of the present invention, the final product of the composite crank 1 may further include a core material 50 , the core material 50 may be made of foamed resin, and the core material 50 is disposed in the socket space S , the opposite ends of the core material 50 are respectively inserted into the first opening 132 of the first metal piece 10 and the second opening 232 of the second metal piece 20, and the rib wall 31 of the reinforcing fiber piece 30 passes through the core material 50, so that the The core material 50 is supported in the socket space S to enhance the structural strength of the composite crank 1 during the hot pressing process of the model.

The manufacturing method of the composite crank 1 with the core material 50 is as follows: after the first metal piece 10, the second metal piece 20, the core material 50, and the reinforcing fiber piece 30 are assembled together, the outer fiber piece 40 is then clad and formed on the outer fiber piece 40. After the first metal piece 10 and the second metal piece 20 are combined with the surface of the core material 50 and the two adhering sections 33 of the reinforcing fiber piece 30, the composite crank 1 with the core material 50 can be obtained, without the need to further The core material 50 is taken out from the outer fiber member 40 . When the core material 50 is a foamed material, since the core material 50 fixes the shrinkage hoop on the reinforcing fiber member 30 after the model hot pressing process, although it does not need to be taken out, it will not cause unnecessary noise.

Preferably, the rib wall 31 of the reinforcing fiber member 30 extends into the first chamber 131 of the first metal member 10 and the second chamber 231 of the second metal member 20, so that the rib wall 31 of the reinforcing fiber member 30 and The first metal part 10 and the second metal part 20 are combined to increase the structure; the two adhering sections 33 of the reinforcing fiber part 30 can be further attached to the first chamber 131 of the first metal part 10 along the reference axis Z. On the opposite side of the direction, and the opposite side of the second chamber 231 of the second metal member 20 along the reference axis Z direction, the through groove 51 of the core material 50 extends to the insertion portion 53 of the core material 50, and the insertion portion 53 is located along the reference axis. The surfaces on the opposite sides of Z are respectively provided with inserting grooves 525. The inserting grooves 525 are connected with the inserting grooves 52 and form a gap. The fitting section 33 of the reinforcing fiber piece 30 can be placed in the inserting groove 52 and the inserting groove 52 along the step difference. Inside the groove 525, and selectively attached to the surfaces of the first chamber 131 of the first metal member 10 and the second chamber 231 of the second metal member 20, the fitting section 33 of the reinforcing fiber member 30 protrudes into the first chamber 131 of the second metal member 20. The two end portions of the first chamber 131 and the second chamber 231 may thus have a step difference from the body section that does not extend into the first chamber 131 and the second chamber 231 . Wherein, an adhesive material can be attached between the bonding section 33 of the reinforced fiber piece 30 and the surfaces of the first chamber 131 and the second chamber 231, so that the bonding section 33 of the reinforced fiber member 30 can be more stably combined on the inner surfaces of the first chamber 131 and the second chamber 231 . In different embodiments, the rib wall 31 and/or the two adhering sections 33 of the reinforcing fiber member 30 can extend into the first chamber 131 of the first metal member 10 and the second chamber of the second metal member 20 individually or simultaneously 231.

In different embodiments, the manufacturing method of the composite crank 1 of the present invention may include the step of bending the two adhering sections 33 of the reinforcing fiber member 30 respectively from the long sides of the rib wall 31 and extending toward the width direction of the composite crank 1, Extending along the width direction can mean that the two bonding sections 33a of the single reinforcing fiber piece 30a face the same direction at the same time (FIG. 11), or that the two bonding sections 33 of the single reinforcing fiber piece 30 face opposite directions respectively (FIG. 4A/4B), or as shown in FIG. 11. Each fitting section 33a/33b of the double reinforcing fiber pieces 30a/30b extends on opposite sides of the rib wall 31 along the short axis Y direction (width direction) at both ends. In other embodiments, the manufacturing method of the composite crank 1 of the present invention may include extending the rib wall 31 and/or the two bonding sections 33 of the reinforcing fiber member 30 into the first opening 132 and the second metal member of the first metal member 10 step of the second opening 232 of the member 20 . In another embodiment, the first connecting section 13 of the first metal piece 10 is provided with a first chamber 131 , and the second connecting section 23 of the second metal piece 20 is provided with a second chamber 231 . The manufacturing method may include: extending the two adhering sections 33 of the reinforcing fiber piece 30 through the first opening 132 and the second opening 232, respectively, into the inner surface of the first chamber 131 attached to the first metal piece 10, and the first opening 132 and the second opening 232 respectively. The inner surfaces of the second chambers 231 of the two metal parts 20 .

Preferably, the two sub-metal parts 201 and 202 of the second metal part 20 are respectively provided with at least one concave part 252 and at least one convex part 251 which are opposite to each other, so as to improve the convenience and stability of assembly.

Please refer to FIG. 11 , in the fourth preferred embodiment of the present invention, the respective bonding sections 33a/33b of the two reinforcing fiber members 30a/30b are opposite to each other along the short axis Y direction (width direction) at both ends of the rib wall 31 The reinforced fiber pieces 30a/30b are extended laterally so that the overall cross-section of the reinforcing fiber pieces 30a/30b is H-shaped. For example, the reinforcing fiber pieces 30a/30b can be folded into a U-shape and an inverted U-shape by using two carbon fiber prepregs, respectively, and then formed by hot pressing and solidifying through a mold. The H-shaped reinforcing fiber pieces 30a/30b are combined, and the structural strength of the composite crank 1 is improved by using the H-shaped reinforcing fiber pieces 30a/30b. Fig. 11 is compared with Fig. 4A/4B. After the two bonding sections 33/33a/33b of the single reinforcing fiber piece 30/30a/30b of Fig. 4A/4B are bent from the long sides of the rib walls 31/31a/31b, the two The fitting section 33/33a/33b may extend in the same direction or in opposite directions (in the short axis Y or the width direction of the composite crank 1) as needed; A composite crank 1 with a curved or deflected structure can be assisted for loading shear stress in a specific direction.

In other embodiments, under the coordination of suitable manufacturing processes, the opposite inner surfaces of the aforesaid fitting sections 33/33a/33b and the outer fiber member 40 may not need to be bent and attached to a large area, and the fitting section 33 /33a/33b can only be used as the adhering end faces of the two sides of the rib wall 31/31a/31b and the inner surfaces of the outer fiber members 40 opposite to each other, in other words, the reinforcing fiber members 30/30a/30b can only be 1-shaped, and the fitting section 33/33a/33b are not bent.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any form. Anyone with ordinary knowledge in the technical field, if they do not deviate from the technical characteristics of the present invention, use the present invention Equivalent embodiments with partial changes or modifications made to the technical content disclosed in the invention, and which do not depart from the technical solution content of the invention, still fall within the scope of the technical features of the invention.

1: Compound crank 10: The first metal piece 11: The first contact hole 110: The first contact hole 13: The first connection segment 131: The first chamber 132: The first opening 133: First connecting peripheral wall 20: Second metal piece 201, 202: Sub-metal parts 21: The second contact hole 210: The second contact hole 2101, 2102: Sub-connector hole 211: Hole Wall 2111, 2112: Sub-hole wall 221, 222: Sub outer ring wall 23: Second connection segment 231: The second chamber 232: Second Opening 233: Second connecting peripheral wall 24: Ring groove 241, 242: Sub-ring grooves 251: convex part 252: Recess 30: Reinforcing fiber parts 31: Rib Wall 33: Fitting segment 40: Outer fiber piece 41a, 41b: inner ring rib 50: core material 51: Grooving 52: Groove 525: Insert groove 53: Insertion part X: long axis Y: short axis Z: reference axis D1: first width D2: Second width G1, G2: Gap S: socket space L1: depth L2: depth T1: Thickness T2: Thickness

FIG. 1 is a three-dimensional external view of the first preferred embodiment of the present invention. FIG. 2 is a top sectional view of the first preferred embodiment of the present invention, showing that it has a reinforcing fiber element. 3A is a side cross-sectional view of another preferred embodiment of the present invention, showing that it has a plurality of reinforcing fiber elements. 3B is a side cross-sectional view of the first preferred embodiment of the present invention, showing a reinforcing fiber element. FIG. 4A is a side cross-sectional view of another preferred embodiment of the present invention, showing a plurality of reinforcing fiber elements. 4B is an end sectional view of the first preferred embodiment of the present invention. FIG. 5 is an exploded perspective view of the first preferred embodiment of the present invention (with the outer fiber member omitted). FIG. 6 is a schematic view of the action of the coated outer fiber member according to the first preferred embodiment of the present invention. FIG. 7 is an exploded perspective view of the second preferred embodiment of the present invention (with the outer fiber member omitted). FIG. 8 is an exploded perspective view of the third preferred embodiment of the present invention (with the outer fiber member omitted). 9 is a top sectional view of the third preferred embodiment of the present invention. 10 is a side cross-sectional view of the third preferred embodiment of the present invention. 11 is an end sectional view of the fourth preferred embodiment of the present invention. FIG. 12 is a block diagram of the manufacturing method of the present invention.

1: Compound crank

10: The first metal piece

11: The first contact hole

110: The first contact hole

13: The first connection segment

131: The first chamber

20: Second metal piece

201, 202: Sub-metal parts

210: The second contact hole

211: Hole Wall

231: The second chamber

24: Ring groove

40: Outer fiber piece

41a, 41b: inner ring rib

50: core material

X: long axis

Z: reference axis

Claims (11)

A compound crank comprising: a first metal piece; a second metal piece arranged at intervals from the first metal piece; an outer fiber piece covering the first metal piece and the second metal piece, the outer fiber piece, the first metal piece and the second metal piece together define a socket space formed between the three; and A reinforced fiber piece is disposed in the socket space, the reinforced fiber piece has a rib wall, the rib wall extends along a thickness direction and a length direction of the composite crank, and the reinforced fiber piece is formed from two opposite sides of the rib wall Two bonding sections are bent and extended, and the two bonding sections extend along the width direction and the length direction of the composite crank and are respectively bonded to the outer fiber piece. The composite crank as claimed in claim 1, wherein the first metal piece has a first connecting hole portion and a first connecting section, and the second metal piece has a second connecting hole portion and a second connecting section, The first connecting segment integrally extends from the first contact hole portion toward the second metal piece, and the second connecting segment integrally extends from the second contact hole portion toward the first metal piece. The composite crank of claim 1, wherein the second connecting section defines a second chamber, and the first connecting section defines a first chamber. A compound crank comprising: a first metal piece, having a first contact hole portion and a first connection section, the first connection section defines a first chamber and a first opening; A second metal piece arranged at intervals from the first metal piece, the second metal piece has a second contact hole portion and a second connecting section, the second connecting section defines a second chamber and a second opening ;as well as An outer fiber piece covering the first metal piece and the second metal piece arranged at intervals, so that the outer fiber piece, the first metal piece and the second metal piece together define a socket space formed in the aforementioned three pieces between, the socket space communicates with the first chamber and the second chamber; Wherein, the first connecting segment integrally extends from the first contact hole portion toward the second metal piece, and the second connecting segment integrally extends from the second contact hole portion toward the first metal piece; Wherein, the outer fiber piece integrally covers the first connecting hole portion, the first connecting section, the socket space, the second connecting section and the second connecting hole portion. The composite crank as claimed in claim 4, wherein the first contact hole portion of the first metal piece has a first contact hole, and the depth of the first chamber in a length direction of the composite crank is greater than that of the first The thickness of the metal piece between the first chamber and the first contact hole. The composite crank as claimed in claim 4, wherein the second contact hole portion of the second metal piece has a second contact hole, and the depth of the second chamber in a length direction of the composite crank is greater than that of the second The thickness of the metal piece between the second chamber and the second contact hole. A compound crank comprising: a first metal piece, having a first contact hole portion and a first connection section, the first connection section defines a first chamber and a first opening; A second metal piece is arranged at intervals from the first metal piece, the second metal piece has a second contact hole portion and a second connection section, the second contact hole portion has a second contact hole, the second the connecting section defines a second chamber and a second opening; and An outer fiber piece wraps the first metal piece and the second metal piece, the outer fiber piece, the first metal piece, and the second metal piece together define a socket space formed between the three, the The socket space communicates with the first chamber of the first metal piece and the second chamber of the second metal piece; Wherein, the second metal piece includes a ring groove surrounding the outer circumference of the second contact hole, and is separated from the second contact hole by a hole wall, and the ring groove communicates with the second chamber. The composite crank as claimed in claim 7, wherein the first connecting section integrally extends from the first connecting hole portion toward the second metal piece, and the second connecting portion faces the first metal member from the second connecting hole portion The outer fiber piece integrally extends, and the outer fiber piece integrally covers the first connection hole portion, the first connection segment, the socket space, the second connection segment and the second connection hole portion. The composite crank as claimed in claim 7, wherein the second metal piece comprises two sub-metal pieces which are mutually butted along a thickness direction of the composite crank. The composite crank according to claim 7, further comprising a reinforcing fiber piece disposed between the first metal piece and the second metal piece, the reinforcing fiber piece extending along a length direction and a thickness direction of the composite crank. A manufacturing method of a composite crank, comprising the following steps: providing a first metal piece, a second metal piece, and a core material; forming a reinforcing fiber piece on the core material, the reinforcing fiber piece passing through the core material; Inserting opposite ends of the core material with the reinforcing fiber member into a first chamber of the first metal member and a second chamber of the second metal member respectively; and overmolding the outer fiber piece on the surface of the first metal piece, the second metal piece and the core material and molding by hot pressing a mold, so that the outer fiber piece is combined with the reinforcing fiber piece; Wherein, the reinforcing fiber piece has a rib wall, the rib wall extends along a thickness direction and a length direction of the composite crank, and the reinforcing fiber piece is bent from two opposite sides of the rib wall to form two fitting sections, the two The bonding section extends along a width direction and a length direction of the composite crank and is respectively bonded to the outer fiber piece.

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