CN220010025U

CN220010025U - Bicycle and sprocket crank

Info

Publication number: CN220010025U
Application number: CN202321531391.0U
Authority: CN
Inventors: 王晓瑛; 杨献仁
Original assignee: Shenzhen Yiwa Brothers Technology Co ltd
Current assignee: Shenzhen Yiwa Brothers Technology Co ltd
Priority date: 2023-06-15
Filing date: 2023-06-15
Publication date: 2023-11-14
Anticipated expiration: 2033-06-15

Abstract

The utility model discloses a bicycle and a sprocket crank, which comprises: a main housing having an integrated structure with an opening portion on an outer side thereof, the main housing including a crank leg portion and a claw portion; the outer side is the side far away from the bicycle body of the bicycle when the sprocket crank is in an installation state; the cover plate is buckled on the opening part and is welded and fixed with the edge of the opening part, and a welding bead between the cover plate and the opening part is positioned in the same plane; the weight-reducing cavity is formed between the main shell and the cover plate. The sprocket crank provided by the utility model solves the problem that the sprocket crank has both rigidity and light weight under the conditions of lower process complexity and processing cost.

Description

Bicycle and sprocket crank

Technical Field

The utility model relates to the technical field of riding equipment, in particular to a bicycle and a chain wheel crank.

Background

This section provides merely background information related to the present disclosure and is not necessarily prior art.

The chain wheel crank of the bicycle is a core transmission part of a rickshaw such as a bicycle. For bicycles or mopeds in the field of professional sports, the performance of the crank determines the function and experience of manual pedaling. The crank of the middle-high-end bicycle meets the requirements of strength, rigidity and reliability, and has higher requirements on light weight, but has the challenges of high structural design and forming process due to rigidity and light weight.

In some prior arts, a hollow structure using a metal material is employed to achieve the light weight object. Specifically, the preformed hollow pipe material can be used for stamping/forging for a plurality of times, the shape of the hollow pipe material is sequentially trimmed into the shape of a crank (comprising a chain wheel bracket and a crank leg), and then the end face and the hole site required for assembling the chain wheel are formed through drilling and milling. However, in the above scheme, a hollow structure needs to be formed by forging for multiple times, and the process complexity and the processing cost are high.

Therefore, how to reduce the crank weight and the process complexity and the processing cost while ensuring the rigidity and reliability of the strength is a problem to be solved by those skilled in the art.

Disclosure of Invention

The utility model aims to solve the problem that the sprocket crank has both rigidity and light weight under the conditions of lower process complexity and processing cost. The aim is achieved by the following technical scheme:

the utility model provides a sprocket crank for a bicycle, comprising:

a main housing having an integrated structure with an opening portion on an outer side thereof, the main housing including a crank leg portion and a claw portion; the outer side is the side far away from the bicycle body of the bicycle when the sprocket crank is in an installation state;

the cover plate is buckled on the opening part and is welded and fixed with the edge of the opening part, and a welding bead between the cover plate and the opening part is positioned in the same plane;

the weight-reducing cavity is formed between the main shell and the cover plate.

In some embodiments, the main housing that is the unitary structure is a cast or die forging.

In some embodiments, further comprising:

the fixing bracket is positioned in the sprocket plate mounting area of the main shell and is used for mounting the sprocket plate; the sprocket plate mounting area is of a hollow structure.

In some embodiments, a positioning groove is formed at the edge of the opening, the cover plate is embedded in the positioning groove, and the welding bead is formed in the positioning groove.

In some embodiments, the crank leg has a central shaft bore and a pedal assembly bore integrated therein.

In some embodiments, the crank leg is further provided with a reinforcing rib, and the reinforcing rib, the outer hole wall of the central shaft hole and the outer hole wall of the pedal assembly hole are of an integrated structure.

In some embodiments, the cover plate is provided with a first matching hole position corresponding to the position of the central shaft hole and a second matching hole position corresponding to the position of the pedal assembly hole.

The utility model also provides a bicycle comprising a sprocket crank as described above.

In one or more embodiments, the sprocket crank provided by the utility model has at least the following technical effects:

in the sprocket crank provided by the utility model, the main shell is of an integrated structure, namely, the crank leg and the claw-shaped part are shell which are open towards the outer side, the claw position for fixing the sprocket is of a hollow structure at the inner side, the end cover is positioned in the area at the outer side of the crank leg, and a welding mode is adopted between the main shell and the closed outer end cover, so that the side edge of the cover and the top end of the side wall of the main shell are on the same plane, and the structure is closed by fusion in a welding mode; therefore, the balance of the light weight of the crank and the strength and rigidity is realized, complex process flows such as cold forging, gluing, machining hollowed-out and the like are reduced, and the highest strength-weight ratio is pursued in an economical way. Therefore, the sprocket crank solves the problem that the sprocket crank has both rigidity and light weight under the conditions of lower process complexity and processing cost.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the utility model. Also, like reference numerals are used to designate like parts throughout the figures. In the drawings:

FIG. 1 is a schematic view of one embodiment of a sprocket crank according to the present utility model;

FIG. 2 is one of the schematic structural views of the main housing in the sprocket crank of FIG. 1;

FIG. 3 is a second schematic illustration of the main housing of the sprocket crank of FIG. 1;

FIG. 4 is a schematic view of the cover plate in the sprocket crank of FIG. 1;

FIG. 5 is a schematic illustration of the assembled structure of the main housing and cover plate of the sprocket crank of FIG. 1;

FIG. 6 is a second schematic illustration of the assembly of the main housing and cover plate of the sprocket crank of FIG. 1;

FIG. 7 is a third schematic illustration of the assembly of the main housing and cover plate of the sprocket crank of FIG. 1;

FIG. 8 is a cross-sectional view of the sprocket crank shown in FIG. 1;

the reference numerals are as follows:

1 is a main shell, 2 is a cover plate;

1A is a fixed bracket;

1A_1 is a first assembly hole, 1A_2 is a second assembly hole, 1A_3 is a third assembly hole, 1A_4 is a fourth assembly hole, and 1A_5 is a hollow structure;

1B is a crank leg;

1B_1 is a weight-reducing cavity, and 1B_2 is a reinforcing rib;

1C is a central shaft hole, and 1D is a pedal assembly hole;

2C is a first matching hole site, and 2D is a second matching hole site;

3 is a welding bead;

and 4 is the plane of the welding bead.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "includes," "including," and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless an order of performance is explicitly stated. It should also be appreciated that additional or alternative steps may be used.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For ease of description, spatially relative terms, such as "inner," "outer," "lower," "below," "upper," "above," and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the example term "below … …" may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatial relative relationship descriptors used herein interpreted accordingly.

Referring to fig. 1 to 8, in one embodiment, the sprocket crank provided by the present utility model is used for a bicycle, and the sprocket crank is mounted on a frame of the bicycle and is used for mounting components such as a sprocket and a pedal, and it should be understood that functions and mounting positions and mounting structures of the sprocket crank on the frame are the same as those of the prior art, and are not repeated. In this embodiment, the right crank is taken as an example, the left crank structure process is identical to that of the right crank, but the sprocket support part is removed, the axle center penetrating the left and right cranks is not marked, and a general scheme (such as a hollow steel axle/aluminum alloy axle, etc.) is adopted.

The sprocket crank comprises a main shell 1, a cover plate 2 and a weight-reducing cavity 1B_1; wherein the main housing 1 has an integral structure having an opening portion on the outer side, and the main housing 1 includes a crank leg portion 1B and a claw portion. It should be noted that the outer side is a side of the sprocket crank which is away from the body of the bicycle in the mounted state, and the inner side herein refers to a side of the sprocket crank which is close to the body in the mounted state. The cover plate 2 is fastened to the opening and welded to the edge of the opening, the weld bead 3 between the cover plate 2 and the opening is in the same plane (namely, the plane 4 where the weld bead is located), and the weight-reducing cavity 1b_1 is formed between the main casing 1 and the cover plate 2.

Because the sprocket crank needs to be provided with pedals and sprockets in the use process, the crank leg part 1B is integrated with a central shaft hole 1C and a pedal assembly hole 1D. In cooperation with this, the cover plate 2 is provided with a first mating hole site 2C corresponding to the position of the central shaft hole 1C, and a second mating hole site 2D corresponding to the position of the pedal assembly hole 1D.

In order to improve the structural strength of the parts, the crank leg may further be provided with a reinforcing rib 1b_2, and the reinforcing rib may be welded, that is, one end of the reinforcing rib 1b_2 is welded to the outer hole wall of the central shaft hole 1C, and the other end thereof is welded to the outer hole wall of the pedal assembly hole 1D. Preferably, the reinforcing rib can be integrally formed on the casting piece or the forging piece, that is, the reinforcing rib, the outer hole wall of the central shaft hole and the outer hole wall of the pedal assembly hole are of an integral structure, and the reinforcing rib structure is formed synchronously in the casting or forging process.

In this embodiment, the main housing 1 and the cover plate 2 are bonded (e.g., friction welding, laser welding, etc.) by a welding process that is reliable and suitable for thin-walled metals, so as to form a fusion and closure that meets the strength, thereby forming an integral closed cavity structure. The main housing 1 and the cover plate 2 are made of light metals such as aluminum alloy or magnesium aluminum alloy, or composite materials. When a metal material is used, the combination mode of the main casing 1 and the cover plate 2 is welding, such as mobile friction welding/laser welding, and when a composite material is used, the combination mode of the main casing 1 and the cover plate 2 can be replaced by a mode suitable for materials, such as ultrasonic welding. The specific welding position is preferably the side wall top end area where the edge of the cover plate 2 is in contact with the main shell 1, so that the welding bead 3 is positioned on a plane, welding equipment can rapidly finish welding, and the sealing of the structure is realized. The welding is not damaged to the strength and the function of the main shell of the crank, and the hollow torsion box structure is obtained through the realization of the closed cavity, so that the overall strength and the rigidity are further enhanced.

Preferably, the main housing 1, which is the one-piece structure, is a casting or a die forging. A casting/liquid die forging mode is adopted to manufacture a thin-wall crank main shell, the main shell 1 is provided with a crank leg structure and a fixed claw-shaped structure of a crank and a chain wheel sheet, and the casting/liquid die forging mode is adopted to realize integrated molding, so that the modeling flexibility is realized. Based on the feasibility of the mold forming, the shell has an open cavity towards the outside at the outer rotation center of the crank and the legs. Meanwhile, the bracket part fixed with the chain wheel sheet adopts a reverse hollowed-out mode to carry out light weight treatment, so that the structural strength is ensured, and further, the smooth integral modeling is realized in appearance.

Further, the sprocket crank further comprises a fixing bracket 1A, wherein the fixing bracket 1A is located in the sprocket plate mounting area of the main housing 1, a plurality of mounting holes are formed in the fixing bracket 1A, for example, 1a_1 shown in fig. 1 is a first mounting hole, 1a_2 is a second mounting hole, 1a_3 is a third mounting hole, 1a_4 is a fourth mounting hole, and each mounting hole is used for mounting a sprocket plate; the chain wheel sheet mounting area is of a hollowed-out structure 1A_5. The edge of the opening part is provided with a positioning groove, the cover plate is embedded in the positioning groove, and the welding bead is formed in the positioning groove. The main casing is provided with a groove (i.e. a positioning groove) for positioning at the position of the open cavity outside the crank, and a cover plate corresponding to the shape of the open cavity is used for sealing so as to improve the sealing effect.

Compared with the prior art, the crank cavity structure formed by the scheme and the gluing is different in that the welding sealing position is positioned on the outer side of the crank, the welding/gluing end face of the gluing structure is positioned on the inner side of the crank, and a non-coplanar gluing mode is adopted. The scheme is different from the forging forming of the hollow pipe/profile in that the hollow structure is not provided at the beginning, and the hollow structure is realized by welding the end surfaces of two parts. Thus, the scheme realizes the balance of the light weight and the strength and the rigidity of the crank through the new design of the structure and the process, and reduces complex process flows such as cold forging, gluing, machining hollowed-out and the like. The highest strength to weight ratio is pursued in an economical manner. The flexibility in molding in the die casting/liquid die forging process is continued. The variety of the appearance of the crank can be realized without being limited by forging. The process flow can be automated. Die casting/liquid die forging forming, end cover stamping/cutting forming, assembly positioning, automatic welding (friction welding/laser welding) +machining and assembling hole site. Realizing the automation of the process, the control of the product precision and the mass production consistency.

In addition to the sprocket crank, the present utility model also provides a bicycle comprising the sprocket crank, and other parts of the bicycle are not described in detail herein.

The present utility model is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present utility model are intended to be included in the scope of the present utility model. Therefore, the protection scope of the utility model is subject to the protection scope of the claims.

Claims

1. A sprocket crank for a bicycle, the sprocket crank comprising:

2. Sprocket crank according to claim 1, wherein the main housing being of the one-piece construction is a casting or a die forging.

3. The sprocket crank as set forth in claim 1, further comprising:

4. The sprocket crank as set forth in claim 1, wherein a positioning groove is provided at an edge of said opening, said cover plate is fitted in said positioning groove, and said weld bead is formed in said positioning groove.

5. The sprocket crank as set forth in claim 1, wherein the crank leg has a central shaft bore and a pedal assembly bore integrated therein.

6. The sprocket crank as set forth in claim 5, wherein the crank leg portion is further provided with a reinforcing rib, the reinforcing rib being of an integral structure with an outer hole wall of the center shaft hole and an outer hole wall of the pedal assembly hole.

7. The sprocket crank as set forth in claim 5, wherein said cover plate is provided with a first mating hole site corresponding to the position of said central shaft hole and a second mating hole site corresponding to the position of said pedal mating hole.

8. A bicycle comprising a sprocket crank as claimed in any one of claims 1 to 7.