Assembly welding type titanium alloy crank for bicycle

Abstract

The utility model discloses an assembly welding type titanium alloy crank for a bicycle, which relates to the field of titanium alloy cranks for bicycles and comprises a titanium alloy middle shaft connector, a body back punching sheet is arranged on one side of the titanium alloy middle shaft connector, a body surface punching sheet is arranged on one side of the body back punching sheet, and titanium alloy pedal connectors are arranged in the body surface punching sheet and the body back punching sheet. A quick splicing assembly is arranged between the body surface punching sheet and the body back punching sheet, the split type crank is improved on the basis of the prior art, and in actual use, through the quick splicing assembly, the problem that when a traditional split type crank is welded and assembled, the body surface punching sheet and the back punching sheet usually depend on a tool clamp to be temporarily positioned is solved. However, fixture positioning has the problems of difficulty in multi-degree-of-freedom adjustment, low repeated positioning precision and the like, and the problem of welding deviation of a middle shaft interface and a pedal interface is easily caused.

Description

Technical Field

[0001] This utility model relates to the field of titanium alloy cranks for bicycles, specifically, to a welded titanium alloy crank for bicycles. Background Technology

[0002] The crank is one of the main power drive components in a bicycle. Traditional manufacturing processes involve forging it from a single piece of steel or aluminum alloy, resulting in low material utilization and excessive strength in some areas. If titanium alloy is used in the crank, directly employing traditional processes would present challenges due to titanium's poor forgeability, making forging difficult and resulting in low material utilization. Furthermore, the demand for stylish aesthetics often leads to excessive strength in the crank design, inevitably resulting in high production costs, poor cost-effectiveness, and making it unaffordable for consumers.

[0003] In traditional split-type cranksets, the body and back flanges are typically temporarily positioned using tooling fixtures during welding and assembly. However, fixture positioning suffers from problems such as difficulty in adjusting multiple degrees of freedom and low repeatability, which can easily lead to welding deviations between the bottom bracket interface and the pedal interface. Utility Model Content

[0004] In view of the problems in the related technologies, this utility model proposes a welded titanium alloy crank for bicycles to overcome the above-mentioned technical problems existing in the existing related technologies.

[0005] Therefore, the specific technical solution adopted by this utility model is as follows:

[0006] A welded titanium alloy crank for bicycles, comprising a crank body;

[0007] The crank body is composed of body front laminations and body back laminations connected by tungsten inert gas welding. It has a bottom bracket mounting hole and a foot pedal mounting hole at both ends.

[0008] The titanium alloy central shaft interface is located in the central shaft mounting hole and is welded to the central shaft mounting hole by tungsten inert gas welding.

[0009] The titanium alloy central shaft interface is located in the foot pedal mounting hole and is welded to the foot pedal mounting hole by tungsten inert gas welding.

[0010] Furthermore, a quick-connect assembly is provided between the front body stamping and the back body stamping. The quick-connect assembly includes a splicing mounting block, which is connected to the front body stamping. The splicing mounting block has a splicing insertion groove inside, and a splicing insert plate is engaged inside the splicing insertion groove. The splicing insert plate is connected to the back body stamping. The splicing insert plate has a fixing slot inside, and a fixing baffle is provided inside the fixing slot. A baffle mounting groove is slidably fitted around the fixing baffle, and a thrust spring is connected above the fixing baffle.

[0011] Furthermore, the titanium alloy central shaft interface includes a sprocket and chain cover connection part, a body stamping mating part is provided around the sprocket and chain cover connection part, and a central shaft connection part is provided on one side of the body stamping mating part.

[0012] Furthermore, the back punch plate includes a back punch plate body, and the back punch plate body has titanium alloy central shaft interface mating holes and titanium alloy foot pedal interface mating holes respectively.

[0013] Furthermore, the front punch plate and the back punch plate engage with each other.

[0014] Furthermore, the titanium alloy foot pedal interface includes a titanium alloy foot pedal interface mating part, and the titanium alloy foot pedal interface mating part has a foot pedal connection part inside.

[0015] The beneficial effects of this utility model are as follows:

[0016] (1) This utility model has made improvements to the existing technology. In actual use, by quickly splicing components, it solves the problem that traditional split cranks usually rely on tooling fixtures to temporarily position the body face stampings and back stampings during welding and assembly. However, the fixture positioning has problems such as difficulty in adjusting multiple degrees of freedom and low repeatability positioning accuracy, which can easily lead to welding deviation between the central shaft interface and the foot pedal interface.

[0017] (2) In practical use, the structure is innovative and efficient, with high material utilization. It requires less material for the same strength and reduces manufacturing difficulty. The easy-to-manufacture and cost-effective product design enables the application of titanium alloys in bicycle cranks. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the main structure of a welded titanium alloy crank for bicycles according to an embodiment of the present utility model;

[0020] Figure 2 This is a schematic diagram of the structure of the sprocket and chain guard connection part in a welded titanium alloy crank for bicycles according to an embodiment of the present utility model;

[0021] Figure 3 This is a schematic diagram of the structure of the back punch of the middle body of a welded titanium alloy crank for bicycles according to an embodiment of the present utility model.

[0022] Figure 4This is a schematic diagram of the structure of the titanium alloy pedal interface in a welded titanium alloy crank for bicycles according to an embodiment of the present utility model;

[0023] Figure 5 This is one of the structural schematic diagrams of a quick-assembly assembly in a welded titanium alloy crank for bicycles according to an embodiment of the present utility model;

[0024] Figure 6 This is the second structural schematic diagram of a quick-assembly assembly in a welded titanium alloy crank for bicycles according to an embodiment of the present utility model.

[0025] In the picture:

[0026] 1. Titanium alloy bottom bracket interface; 101. Sprocket and chain guard connection part; 102. Body stamped plate mating part; 103. Bottom bracket connection part; 2. Body back stamped plate; 201. Titanium alloy bottom bracket interface mating hole; 202. Back stamped plate body; 203. Titanium alloy pedal interface mating hole; 3. Body front stamped plate; 4. Titanium alloy pedal interface; 401. Body stamped plate mating part; 402. Pedal connection part; 5. Quick-connect assembly; 501. Assembly mounting block; 502. Assembly insertion slot; 503. Assembly insert plate; 504. Fixing clip slot; 505. Fixing baffle; 506. Baffle mounting slot; 507. Thrust spring. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] According to an embodiment of the present invention, a welded titanium alloy crank for bicycles is provided, including a crank body;

[0029] The crank body is composed of body front laminations and body back laminations connected by tungsten inert gas welding. It has a bottom bracket mounting hole and a foot pedal mounting hole at both ends.

[0030] The titanium alloy central shaft interface is located in the central shaft mounting hole and is welded to the central shaft mounting hole by tungsten inert gas welding.

[0031] The titanium alloy central shaft interface is located in the foot pedal mounting hole and is welded to the foot pedal mounting hole by tungsten inert gas welding.

[0032] like Figure 1-6As shown, in the embodiment of this utility model, a quick-connect assembly 5 is provided between the body face stamp 3 and the body back stamp 2. The quick-connect assembly 5 includes a splicing mounting block 501, which is connected to the body face stamp 3. A splicing insertion groove 502 is provided inside the splicing mounting block 501. A splicing insert plate 503 is engaged inside the splicing insertion groove 502. The splicing insert plate 503 is connected to the body back stamp 2. A fixing slot 504 is provided inside the splicing insert plate 503. A fixing baffle 505 is provided inside the fixing slot 504. A baffle mounting groove 506 is slidably fitted around the fixing baffle 505. A thrust spring 507 is connected above the fixing baffle 505.

[0033] With the above technical solution, when the body front punch 3 and the body back punch 2 are spliced, the splicing insert plate 503 is inserted into the splicing insertion groove 502 in the splicing mounting block 501. After the splicing insert plate 503 is fully inserted into the splicing insertion groove 502, the fixing baffle 505 in the fixing slot 504 is pushed into the fixing slot 504 under the action of the thrust spring 507, thereby achieving the function of fixing the splicing insert plate 503 in the splicing insertion groove 502. This facilitates the splicing of the body front punch 3 and the body back punch 2, and makes it easier to fix the body front punch 3 and the body back punch 2 during welding. This avoids the problems of difficulty in adjusting multiple degrees of freedom and low repeatability accuracy in fixture positioning, which can easily lead to welding deviation between the titanium alloy central shaft interface and the titanium alloy foot pedal interface.

[0034] Among them, the body front stamping 3 has a splicing groove on the splicing edge, which facilitates the splicing of the body front stamping 3 and the body back stamping 2.

[0035] like Figure 1-6 As shown, according to an embodiment of the present invention, a welded titanium alloy crank for bicycles includes a titanium alloy bottom bracket interface 1 comprising a sprocket and chain cover connecting part 101, a body stamping mating part 102 surrounding the sprocket and chain cover connecting part 101, and a bottom bracket connecting part 103 on one side of the body stamping mating part 102.

[0036] Through the above technical solution, the titanium alloy bottom bracket interface 1 consists of a sprocket and chain guard connection part 101, a body stamping mating part 102, and a bottom bracket connection part 103. The sprocket and chain guard connection part 101 is designed according to the installation requirements of the sprocket or chain guard. The body stamping mating part 102 is designed according to the structural and welding requirements of the body back stamping 2 and body front stamping 3. The bottom bracket connection part 103 is designed according to the mating requirements of the bottom bracket of the bicycle. The titanium alloy bottom bracket interface 1 is an integral part, made of titanium alloy tubing or bar material through turning, milling, and other machining processes.

[0037] like Figure 1-6As shown, according to an embodiment of the present invention, a welded titanium alloy crank for bicycles includes a back punch 2, which has a titanium alloy bottom bracket interface mating hole 201 and a titanium alloy pedal interface mating hole 203 respectively. The body front punch 3 engages with the body back punch 2.

[0038] The above technical solution comprises a titanium alloy bottom bracket interface mating hole 201, a back stamping body 202, and a titanium alloy foot pedal interface mating hole 203. The titanium alloy bottom bracket interface mating hole 201 is designed based on the structure and welding requirements of the body stamping mating part 102 in the titanium alloy bottom bracket interface 1. The back stamping body 202 is designed based on aesthetic requirements combined with stamping and welding processes. The titanium alloy foot pedal interface mating hole 203 is designed based on the structure and welding requirements of the titanium alloy foot pedal interface mating part 401 in the titanium alloy foot pedal interface 4. The foot pedal connection part 402 is a sheet metal stamping part, and its sheet thickness is determined appropriately based on the crank's strength requirements.

[0039] like Figure 1-6 As shown, the assembled titanium alloy crank for bicycles according to an embodiment of the present utility model includes a titanium alloy pedal interface 4 including a titanium alloy pedal interface mating part 401, and a pedal connecting part 402 is provided inside the titanium alloy pedal interface mating part 401.

[0040] The above technical solution comprises a titanium alloy foot pedal interface mating part 401 and a foot pedal connecting part 402. The titanium alloy foot pedal interface mating part 401 should be designed according to the structure and welding requirements of the titanium alloy foot pedal interface mating hole 203 in the body stamping; the foot pedal connecting part 402 should be designed according to the mating requirements of the foot pedal it is fitted with, and is normally a left-hand or right-hand thread. The titanium alloy foot pedal interface 4 is a single piece, machined from titanium alloy tubing or bar material.

[0041] To facilitate understanding of the above-mentioned technical solutions of this utility model, the working principle or operation method of this utility model in actual process will be described in detail below.

[0042] In summary, using the above-mentioned technical solution of this utility model, titanium alloys have poor forgeability. Furthermore, when titanium alloys are heated in a non-protected atmosphere furnace, or during workpiece movement after heating, a highly brittle oxide film forms on the surface, leading to cracks in the forgings and a low yield rate of forged products. Regarding bicycle cranks, current forging is limited to solid parts. Titanium alloys have extremely high tensile strength, and cranks that meet the requirements of fashionable and aesthetically pleasing designs are often overstrength; simultaneously, the material utilization rate is low after forging and subsequent machining. This invention relates to the design and manufacture of titanium alloy bicycle cranks. Firstly, it replaces hot forging with machining, sheet metal stamping, and gas tungsten inert gas welding (GTAW). During GTAW, an inert gas shielded the crank throughout the process, preventing thermal oxidation and significantly reducing manufacturing difficulty. Secondly, the material utilization rate of machining bars or tubes and sheet metal stamping is much higher than that of forging, improving material utilization. Thirdly, the crank of this invention can adopt a hollow body design, avoiding excessive strength and significantly reducing product weight. Fourthly, it improves the product's cost-effectiveness and realizes the application of titanium alloy materials in the production of bicycle cranks.

[0043] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model are included within the protection scope of the present utility model.

Claims

1. A welded titanium alloy crank for bicycles, characterized in that, Including the crank body; The crank body is composed of a body front stamping (3) and a body back stamping (2) connected by tungsten inert gas welding, and its two ends are provided with a central shaft mounting hole and a foot pedal mounting hole; The titanium alloy central shaft interface (1) is located in the central shaft mounting hole and is welded to the central shaft mounting hole by tungsten inert gas welding; The titanium alloy central shaft interface (1) is located in the foot pedal mounting hole and is welded to the foot pedal mounting hole by tungsten inert gas welding; A quick-connect assembly (5) is provided between the body front punch (3) and the body back punch (2). The quick-connect assembly (5) includes a splicing mounting block (501). The splicing mounting block (501) is connected to the body front punch (3). A splicing insertion groove (502) is provided inside the splicing mounting block (501). A splicing insert plate (503) is engaged inside the splicing insertion groove (502). The splicing insert plate (503) is connected to the body back punch (2). A fixing slot (504) is provided inside the splicing insert plate (503). A fixing baffle (505) is provided inside the fixing slot (504). A baffle mounting groove (506) is slidably fitted around the fixing baffle (505). A thrust spring (507) is connected above the fixing baffle (505).

2. The welded titanium alloy crank for bicycles according to claim 1, characterized in that, The titanium alloy central shaft interface (1) includes a sprocket and chain cover connection part (101), and a body stamp mating part (102) is provided around the sprocket and chain cover connection part (101). A central shaft connection part (103) is provided on one side of the body stamp mating part (102).

3. A welded titanium alloy crank for bicycles according to claim 2, characterized in that, The back punch plate (2) includes a back punch plate body (202), and the back punch plate body (202) is provided with a titanium alloy central shaft interface mating hole (201) and a titanium alloy foot pedal interface mating hole (203).

4. A welded titanium alloy crank for bicycles according to claim 3, characterized in that, The body front punch (3) engages with the body back punch (2).

5. A welded titanium alloy crank for bicycles according to claim 4, characterized in that, The titanium alloy foot pedal interface (4) includes a titanium alloy foot pedal interface mating part (401), and a foot pedal connection part (402) is provided inside the titanium alloy foot pedal interface mating part (401).

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