A welding tool for a front triangle of a bicycle frame, wherein the upper and lower tubes are in a bent pipe structure

Abstract

A front triangle welding tool of a bicycle frame with upper and lower tube structure, comprising a head tube positioning and clamping mechanism, an upper and lower tube positioning and clamping mechanism, a vertical tube and five-way tube positioning and clamping mechanism, and a base, wherein the base is provided with a front and rear through structure slide rail along a central axis; the head tube positioning and clamping mechanism, the upper and lower tube positioning and clamping mechanism, the vertical tube and five-way tube positioning and clamping mechanism are sequentially installed on the base, and a sliding groove structure matched with the slide rail on the base is arranged at the bottom of the head tube positioning and clamping mechanism, the upper and lower tube positioning and clamping mechanism, the vertical tube and five-way tube positioning and clamping mechanism. The base cooperates with the head tube positioning and clamping mechanism, the upper and lower tube positioning and clamping mechanism, the vertical tube and five-way tube positioning and clamping mechanism to realize accurate positioning of each component in the front triangle part of the bicycle frame, and to improve the welding quality of the workpiece, ensure the control reliability and riding safety of the bicycle product.

Description

Technical Field

[0001] This utility model relates to the technical field of bicycle production equipment, specifically a welding fixture for the front triangle of a bicycle frame with a bent upper and lower tube structure. Background Technology

[0002] As attached Figure 1 As shown, a bicycle frame front triangle component 1 comprises a head tube 1-1, an upper tube 1-2, a lower tube 1-5, a riser 1-3, and a bottom bracket 1-4. These components are assembled into a single unit through welding. During the welding of this bicycle frame front triangle component 1, to ensure the reliability of bicycle handling and riding safety, according to relevant technical requirements, the central axes of the head tube 1-1, upper tube 1-2, lower tube 1-5, and riser 1-3 must be located in the same plane perpendicular to the central axis of the bottom bracket 1-4. Furthermore, since both the upper tube 1-2 and lower tube 1-5 in this bicycle frame front triangle component 1 are curved tubes with a small distance between them, if a traditional straight tube positioning and clamping structure is used for the upper and lower tubes, there is a problem of interference between different parts, making it difficult to accurately position the upper tube 1-2 and lower tube 1-5. Therefore, it is necessary to optimize the design of a welding fixture suitable for bicycle frame front triangles with curved upper and lower tube structures. Utility Model Content

[0003] This utility model provides a welding fixture for the front triangle of a bicycle frame with curved upper and lower tubes. It aims to achieve accurate positioning of each component in the front triangle of the bicycle frame by cooperating with the base, head tube positioning and clamping mechanism, upper and lower tube positioning and clamping mechanism, and riser and bottom bracket positioning and clamping mechanism, thereby improving the welding quality of the workpiece and ensuring the reliability of bicycle operation and riding safety.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A welding fixture for the front triangle of a bicycle frame with curved upper and lower tubes includes a head tube positioning and clamping mechanism, an upper and lower tube positioning and clamping mechanism, a riser and bottom bracket positioning and clamping mechanism, and a base. The base is provided with a slide rail with a through structure along its central axis. The head tube positioning and clamping mechanism, the upper and lower tube positioning and clamping mechanism, and the riser and bottom bracket positioning and clamping mechanism are sequentially installed on the base. A groove structure that cooperates with the slide rail on the base is provided at the bottom of the head tube positioning and clamping mechanism, the upper and lower tube positioning and clamping mechanism, and the riser and bottom bracket positioning and clamping mechanism.

[0006] The aforementioned upper and lower tubes are welding fixtures for the front triangle of a bicycle frame with a bent tube structure. The upper and lower tube positioning and clamping mechanism includes an L-shaped support frame, positioning blocks, and upper and lower tube clamping clamp assembly. The horizontal seat of the L-shaped support frame is detachably assembled with the base. An L-shaped support frame position adjustment groove is provided on the bottom surface of the horizontal seat. At least two sets of vertical elongated holes are arranged parallel to each other on the vertical wall of the L-shaped support frame, and at least two positioning blocks are installed in the vertical elongated holes. The positioning blocks include an upper tube positioning block and a lower tube positioning block. The upper and lower tube clamping clamp assembly includes upper and lower parts, which are respectively fitted with different vertical elongated holes. The upper part cooperates with the upper tube positioning block to position and clamp the upper tube, and the lower part cooperates with the lower tube positioning block to position and clamp the lower tube.

[0007] The aforementioned upper and lower tubes are welding fixtures for the front triangle of a bicycle frame with a bent tube structure. The upper tube positioning block is provided with an arc groove that matches the outer surface of the upper tube; the lower tube positioning block is provided with an arc groove that matches the outer surface of the lower tube.

[0008] The aforementioned upper and lower tubes are welding fixtures for the front triangle of a bicycle frame with a bent tube structure. The positioning and clamping mechanism for the riser and bottom bracket includes a U-shaped support frame, a bottom bracket positioning and clamping assembly, and a riser positioning and clamping assembly. The two vertical walls of the U-shaped support frame are of unequal height, with the higher vertical wall located at the rear. Several assembly holes for the riser positioning and clamping assembly are provided on the higher vertical wall. A U-shaped support frame positioning groove is provided on the bottom surface of the U-shaped support frame, and the bottom surface of the U-shaped support frame is fixedly assembled with the base. The riser positioning and clamping assembly includes a riser clamping clamp and a riser pressing clamp. The riser clamping clamp and the riser pressing clamp are installed on the higher vertical wall of the U-shaped support frame through the assembly holes of the riser positioning and clamping assembly. The bottom bracket positioning and clamping assembly includes a bottom bracket positioning seat and a bottom bracket clamping seat arranged opposite each other. The bottom bracket positioning seat is installed on the higher vertical wall of the U-shaped support frame, and the bottom bracket clamping seat is installed on the lower vertical wall of the U-shaped support frame.

[0009] The aforementioned upper and lower tubes are welding fixtures for the front triangle of a bicycle frame with a bent tube structure. The head tube positioning and clamping mechanism includes a head tube support frame, a head tube positioning support block assembly, and a head tube side push clamping assembly. The head tube support frame is an inverted T-shaped bracket, with its horizontal seat and base detachably assembled. A head tube support frame position adjustment groove is provided on the bottom surface of the horizontal seat. An elongated hole for adjusting the vertical position and several sets of head tube positioning support block assembly assembly holes are provided on the vertical wall of the T-shaped bracket. The head tube positioning support block assembly is installed on the vertical wall of the T-shaped bracket. The head tube side push clamping assembly is fitted with the head tube positioning support block assembly.

[0010] The aforementioned upper and lower tubes are welded fixtures for the front triangle of a bicycle frame with a bent tube structure. The head tube positioning and clamping mechanism includes a head tube support frame, a head tube positioning support block assembly, and a head tube side push clamping assembly. The head tube support frame adopts an L-shaped bracket, and the horizontal bottom surface of the L-shaped bracket is detachably assembled with the base. The horizontal bottom surface is provided with a head tube support frame position adjustment groove. The vertical wall of the L-shaped support frame is provided with vertical position adjustment elongated holes and several sets of head tube positioning support block assembly assembly holes. The head tube positioning support block assembly is installed on the vertical wall of the L-shaped bracket. The head tube side push clamping assembly is fitted with the head tube positioning support block assembly.

[0011] The aforementioned upper and lower tubes are the welding fixtures for the front triangle of a bicycle frame with a bent tube structure. The upper and lower tube clamping clamp assembly, the head tube side push clamping assembly, the riser clamping clamp, the riser lower clamping clamp, and the bottom tube clamping seat adopt a manual control structure.

[0012] The aforementioned upper and lower tubes are the welding fixtures for the front triangle of a bicycle frame with a bent tube structure. The upper and lower tube clamping clamp assembly, the head tube side push clamping assembly, the riser clamping clamp, the riser lower clamping clamp, and the bottom tube clamping seat adopt a pneumatic control structure.

[0013] This utility model provides a welding fixture for the front triangle of a bicycle frame with bent upper and lower tubes. Its base has a slide rail with a through structure along the central axis. Slide grooves that mate with the slide rails on the base are provided at the bottom of the head tube positioning and clamping mechanism, the upper and lower tube positioning and clamping mechanism, and the riser and bottom bracket positioning and clamping mechanism. The riser and bottom bracket positioning and clamping mechanism can first achieve center positioning by the U-shaped support frame positioning groove on its bottom surface engaging with the base slide rail. Then, the U-shaped support frame is fixedly assembled to the base. During the welding of the front triangle of the bicycle frame, the bottom bracket can be positioned and clamped using the bottom bracket positioning seat and the bottom bracket clamping seat. Using the bottom bracket as a positioning reference, the front and rear positions of the head tube positioning clamping mechanism and the upper and lower tube positioning clamping mechanism are adjusted to adapt to the structural dimensions of the welded workpiece. During this process, the base slide rail cooperates with the sliding groove structure of the head tube positioning clamping mechanism and the upper and lower tube positioning clamping mechanism to ensure that the central axes of the head tube, upper tube, lower tube, and riser of the bicycle frame's front triangle are located in the same plane perpendicular to the central axis of the bottom bracket. This invention also improves the upper and lower tube positioning clamping mechanism by utilizing two or more sets of parallel vertical elongated holes on the vertical wall of the L-shaped support frame to assemble the upper and lower tube positioning blocks and the upper and lower tube clamping clamp assembly, avoiding interference between different parts. In summary, this invention achieves accurate positioning of each component in the bicycle frame's front triangle assembly, thereby improving the welding quality of the workpiece and ensuring the reliability of bicycle handling and riding safety. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the front triangle component of a bicycle frame with curved upper and lower tubes.

[0015] Figure 2 This is a schematic diagram of the overall structure of this utility model;

[0016] Figure 3 yes Figure 2 K-direction view;

[0017] Figure 4 This is a schematic diagram of the head tube positioning and clamping mechanism;

[0018] Figure 5 This is a schematic diagram of the upper and lower tube positioning unit structure;

[0019] Figure 6 This is a schematic diagram of the positioning and clamping mechanism for risers and bottom brackets;

[0020] Figure 7 This is a schematic diagram of the working state of this utility model;

[0021] Figure 8 yes Figure 7 K-direction view;

[0022] Figure 9 This is a schematic diagram of the structure of an enhanced embodiment of this utility model;

[0023] Figure 10 yes Figure 9 The K-direction view.

[0024] Explanation of each label in the diagram:

[0025] 1 is the front triangle of the bicycle frame, 1-1 is the head tube, 1-2 is the top tube, 1-3 is the seat tube, 1-4 is the bottom bracket tube, and 1-5 is the down tube;

[0026] 2 is the head tube positioning and clamping mechanism, 2-1 is the head tube support frame, 2-1-1 is the head tube support frame position adjustment slide groove, 2-1-2 is the upper and lower position adjustment elongated hole, 2-1-3 is the head tube positioning support block assembly assembly hole, 2-2 is the head tube positioning support block assembly, and 2-3 is the head tube side push clamping assembly.

[0027] 3 is the upper and lower tube positioning and clamping mechanism, 3-1 is the L-shaped support frame, 3-1-1 is the L-shaped support frame position adjustment slide, 3-1-2 is the vertical elongated hole, 3-2 is the upper tube positioning block, 3-3 is the lower tube positioning block, and 3-4 is the upper and lower tube clamping clamp assembly.

[0028] 4 is the positioning and clamping mechanism for risers and bottom brackets; 4-1 is the U-shaped support frame; 4-1-1 is the positioning slide groove for the U-shaped support frame; 4-1-2 is the assembly hole for the riser positioning and clamping assembly; 4-2 is the positioning and clamping assembly for bottom brackets; 4-2-1 is the positioning seat for bottom brackets; 4-2-2 is the clamping seat for bottom brackets; 4-3 is the positioning and clamping assembly for risers; 4-3-1 is the riser clamping clamp; 4-3-2 is the riser pressing clamp.

[0029] 5 represents the base, and 5-1 represents the slide rail. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0031] Referring to Figure 1, a bicycle frame front triangle component 1 comprises a head tube 1-1, an upper tube 1-2, a lower tube 1-5, a riser 1-3, and a bottom bracket 1-4. All components are made of ordinary carbon steel pipes and are assembled into a single unit through welding. During the welding of this bicycle frame front triangle component 1, to ensure the reliability of the bicycle's handling and the safety of riding, according to relevant technical requirements, the central axes of the head tube 1-1, upper tube 1-2, lower tube 1-5, and riser 1-3 must be located in the same plane perpendicular to the central axis of the bottom bracket 1-4. Furthermore, since both the upper tube 1-2 and lower tube 1-5 in this bicycle frame front triangle component 1 are curved tubes with a small distance between them, if a traditional straight tube positioning and clamping structure is used for the upper and lower tubes, there will be interference between different parts, making it difficult to accurately position the upper tube 1-2 and lower tube 1-5.

[0032] See Figure 1 , Figure 2 , Figure 3 , Figure 7 , Figure 8 In order to achieve Figure 1The present invention provides a welding fixture for the front triangle of a bicycle frame, which is a curved tube structure. It includes a head tube positioning and clamping mechanism 2, an upper and lower tube positioning and clamping mechanism 3, a riser and bottom bracket positioning and clamping mechanism 4, and a base 5. The base 5 is provided with a slide rail 5-1 with a through structure along the central axis. The head tube positioning and clamping mechanism 2, the upper and lower tube positioning and clamping mechanism 3, and the riser and bottom bracket positioning and clamping mechanism 4 are sequentially installed on the base 5. A groove structure that cooperates with the slide rail 5-1 on the base 5 is provided at the bottom of the head tube positioning and clamping mechanism 2, the upper and lower tube positioning and clamping mechanism 3, and the riser and bottom bracket positioning and clamping mechanism 4. When using this utility model to assemble and weld the front triangle component 1 of a bicycle frame, the bottom tube 1-4 can first be positioned and clamped by the bottom tube positioning and clamping mechanism 4. Then, using the central axis of the bottom tube 1-4 as the positioning reference, the front and rear positions of the head tube positioning and clamping mechanism 2 and the upper and lower tube positioning and clamping mechanism 3 are adjusted to adapt to the structural dimensions of the welded workpiece. During this process, the slide rail 5-1 on the base 5 cooperates with the slide groove structure of the head tube positioning and clamping mechanism and the upper and lower tube positioning and clamping mechanism to ensure that the central axes of the head tube 1-1, upper tube 1-2, lower tube 1-5, and upright tube 1-3 of the front triangle component 1 of the bicycle frame are located in the same plane perpendicular to the central axis of the bottom tube 1-4.

[0033] The following describes the head tube positioning and clamping mechanism 2, the upper and lower tube positioning and clamping mechanism 3, and the riser and bottom tube positioning and clamping mechanism 4 in detail according to the attached drawings:

[0034] See Figure 4The present invention relates to a welding fixture for the front triangle of a bicycle frame with a bent tube structure. Its head tube positioning and clamping mechanism 2 includes a head tube support frame 2-1, a head tube positioning support block assembly 2-2, and a head tube side-push clamping assembly 2-3. The head tube support frame 2-1 is an inverted T-shaped bracket, with its horizontal seat and base 5 assembled by bolts. A head tube support frame position adjustment groove 2-1-1 is provided on the bottom surface of the horizontal seat. Vertical position adjustment elongated holes 2-1-2 and several sets of head tube positioning support block assembly assembly holes 2-1-3 are provided on the vertical wall of the T-shaped bracket. When the position of the head tube positioning and clamping mechanism 2 needs to be adjusted according to the size specifications of different batches of workpieces: the head tube support frame position adjustment groove... 2-1-1 slides back and forth along the slide rail 5-1 on the base 5. The head tube positioning support block assembly 2-2 can move up and down along the vertical adjustment elongated hole 2-1-2 set on the vertical wall of the T-shaped bracket, thereby ensuring that the central axis of the head tube 1-1 of the workpiece is always in the same plane perpendicular to the central axis of the five-way tube 1-4 during the adjustment process. The head tube positioning support block assembly 2-2 is installed on the vertical wall of the head tube support frame 2-1. The head tube side push clamping assembly 2-3 is fitted with the head tube positioning support block assembly 2-2. The head tube side push clamping assembly 2-3 can adopt a manual or pneumatic control structure. The positioned head tube 1-1 workpiece can be pressed and fixed by the action of the head tube side push clamping assembly 2-3.

[0035] See Figure 4The present invention relates to a welding fixture for the front triangle of a bicycle frame with a bent tube structure. Its upper and lower tube positioning and clamping mechanism 3 includes an L-shaped support frame 3-1, positioning blocks, and upper and lower tube clamping clamp assembly 3-4. The horizontal seat of the L-shaped support frame 3-1 is assembled with the base 5 via bolts. An L-shaped support frame position adjustment groove 3-1-1 is provided on the bottom surface of the horizontal seat. Two sets of vertical elongated holes 3-1-2 are arranged parallel to each other on the vertical wall of the L-shaped support frame 3-1. Each set of vertical elongated holes 3-1-2 is equipped with two positioning blocks, one upper and one lower. The positioning blocks include an upper tube positioning block 3-2 and a lower tube positioning block 3-3, located at the upper part of the two sets of vertical elongated holes. The positioning block is the upper tube positioning block 3-2, and the two positioning blocks located below the two sets of vertical elongated holes are the lower tube positioning blocks 3-3. The upper tube positioning block 3-2 is provided with an arc groove that matches the outer surface of the upper tube 1-2, and the lower tube positioning block 3-3 is provided with an arc groove that matches the outer surface of the lower tube 1-5. The upper and lower tube clamping clamp assembly 3-4 includes upper and lower parts, which are respectively fitted with the two sets of vertical elongated holes 3-1-2. The upper part cooperates with the upper tube positioning block 3-2 to clamp the positioning of the upper tube 1-2, and the lower part cooperates with the lower tube positioning block 3-3 to clamp the positioning of the lower tube 1-5. The upper and lower tube clamping clamp assembly 3-4 can adopt a manual or pneumatic control structure. When the position of the upper and lower tube positioning and clamping mechanism 3 needs to be adjusted according to the size specifications of different batches of workpieces: the L-shaped support frame position adjustment slide 3-1-1 slides back and forth along the upper slide rail 5-1 of the base 5, the upper tube positioning block 3-2, the lower tube positioning block 3-3 and the upper and lower tube clamping clamp assembly 3-4 can be adjusted up and down along the two sets of vertical long holes 3-1-2 set on the vertical wall of the L-shaped support frame, and the angle can be adjusted by rotating around the central axis perpendicular to the vertical wall of the L-shaped support frame 3-1. This ensures that during the adjustment process, the central axes of the upper tube 1-2 and lower tube 1-5 of the workpiece are always in the same plane perpendicular to the central axis of the five-way tube 1-4.

[0036] See Figure 6The present invention relates to a welding fixture for the front triangle of a bicycle frame with a bent tube structure. Its upright and bottom bracket positioning and clamping mechanism 4 includes a U-shaped support frame 4-1, a bottom bracket positioning and clamping assembly 4-2, and an upright positioning and clamping assembly 4-3. The two vertical walls of the U-shaped support frame 4-1 are of unequal height, with the higher vertical wall located at the rear. Several upright positioning and clamping assembly mounting holes 4-1-2 are provided on the higher vertical wall. A U-shaped support frame positioning groove 4-1-1 is provided on the bottom surface of the U-shaped support frame 4-1. The bottom surface of the U-shaped support frame 4-1 is fixedly assembled with the base 5. The upright positioning and clamping mechanism... Component 4-3 includes a riser clamping clamp 4-3-1 and a riser pressing clamp 4-3-2. The riser clamping clamp 4-3-1 and the riser pressing clamp 4-3-2 are mounted on the higher vertical wall of the U-shaped support frame 4-1 through the riser positioning and clamping component assembly hole 4-1-2. The bottom bracket positioning and clamping component 4-2 includes a bottom bracket positioning seat 4-2-1 and a bottom bracket clamping seat 4-2-2 arranged opposite to each other. The bottom bracket positioning seat 4-2-1 is mounted on the higher vertical wall of the U-shaped support frame 4-1, and the bottom bracket clamping seat 4-2-2 is mounted on the lower vertical wall of the U-shaped support frame 4-1. The riser clamping clamp 4-3-1, the riser pressing clamp 4-3-2, and the bottom bracket clamping seat 4-2-2 in the riser and bottom bracket positioning and clamping mechanism 4 of this utility model can be manually or pneumatically controlled.

[0037] See Figures 1 to 8When using this utility model to weld the front triangle component of a bicycle frame, firstly, according to the structural dimensions of the front triangle component 1 of this batch of bicycle frames, fix and assemble the seat tube and bottom bracket positioning and clamping mechanism 4 with the base 5, so that the U-shaped support frame positioning groove on the bottom surface of the U-shaped support frame in the seat tube and bottom bracket positioning and clamping mechanism 4 cooperates with the slide rail 5-1 of the base 5 to achieve center positioning. Then, the bottom bracket 1-4 is positioned and clamped by the bottom bracket positioning seat 4-2-1 and the bottom bracket clamping seat 4-2-2, and then... Using the bottom bracket 1-4 as a positioning reference, the front and rear positions of the head tube positioning clamping mechanism 2 and the upper and lower tube positioning clamping mechanism 3 are adjusted. After adapting to the structural dimensions in the length direction of the welded workpiece, the head tube positioning clamping mechanism 2 and the upper and lower tube positioning clamping mechanism 3 are fixedly assembled to the base 5 with bolts. During this process, the slide rail 5-1 of the base 5 cooperates with the sliding groove structure on the bottom surface of the head tube positioning clamping mechanism 2 and the upper and lower tube positioning clamping mechanism 3 to ensure the proper functioning of the head tube 1-1, upper tube 1-2, and lower tube of the bicycle frame front triangle. The central axes of pipes 1-5 and riser 1-3 are located in the same plane perpendicular to the central axis of bottom bracket 1-4; then, the vertical and horizontal positions of the riser clamping clamp 4-3-1 and the riser lower clamp 4-3-2 in the riser and bottom bracket positioning clamping mechanism 4, the upper pipe positioning block 3-2, the lower pipe positioning block 3-3 and the upper and lower pipe clamping clamp assembly 3-4 in the upper and lower pipe positioning clamping mechanism 3, and the head pipe positioning support block assembly 2-2 and the head pipe side push clamping assembly 2-3 in the head pipe positioning clamping mechanism are adjusted respectively; After adapting the structural dimensions of the workpiece in the height direction, the riser 1-3 is locked and fixed using the riser clamping clamp 4-3-1 and the riser lower clamp 4-3-2. The upper pipe 1-2 and the lower pipe 1-5 are locked and fixed using the upper pipe positioning block 3-2, the lower pipe positioning block 3-3, and the upper and lower pipe clamping clamp assembly 3-4. The head pipe 1-1 is locked and fixed using the head pipe positioning support block assembly 2-2 and the head pipe side push clamping assembly 2-3. The workpiece positioning and clamping operation is now complete, and the welding operation can begin.

[0038] See Figure 9 , Figure 10The figure shows an enhanced embodiment of this utility model, which is suitable for welding the front triangle component of a bicycle frame with larger dimensions. It improves the head tube support frame 2-1 in the head tube positioning and clamping mechanism 2 by replacing it with an L-shaped bracket, so that the vertical wall of the head tube support frame 2-1 and the vertical wall of the L-shaped support seat 3-1 of the upper and lower tube positioning and clamping mechanism 3 are located in the same plane, facilitating the loading and unloading of workpieces and avoiding collisions between the workpiece and the head tube support frame 2-1 during loading and unloading. In this embodiment, at least four sets of upper and lower tube positioning blocks 3-3 and upper and lower tube clamping clamp assemblies 3-4 are provided in the upper and lower tube positioning and clamping mechanism 3. The upper tube 1-2 and lower tube 1-5 are respectively positioned and clamped by two sets of clamping clamps and positioning blocks. This improves the reliability of positioning and clamping the upper and lower tubes. Furthermore, two sets of vertical clamping clamps are installed in the vertical positioning clamping assembly 4-3 of the vertical tube and five-way tube positioning clamping mechanism 4. The vertical tube pressing clamp 4-3-2 is mounted on the higher vertical wall of the U-shaped support frame 4-1 via an inverted L-shaped seat 4-3-3, increasing the strength and rigidity of the vertical tube pressing clamp 4-3-2 during the pressing process. This allows the vertical tube 1-3 in the front triangle component 1 of the bicycle frame to bear a vertically downward clamping force, further ensuring that the central axes of the head tube 1-1, upper tube 1-2, lower tube 1-5, and vertical tube 1-3 in the front triangle component 1 of the bicycle frame are located in the same plane perpendicular to the central axis of the five-way tube 1-4, thus better guaranteeing product quality.

Claims

1. A welding fixture for the front triangle of a bicycle frame with bent upper and lower tubes, characterized in that: It includes a head tube positioning and clamping mechanism (2), an upper and lower tube positioning and clamping mechanism (3), a riser and five-way tube positioning and clamping mechanism (4), and a base (5); the base (5) is provided with a slide rail (5-1) with a front and rear through structure along the central axis; the head tube positioning and clamping mechanism (2), the upper and lower tube positioning and clamping mechanism (3), and the riser and five-way tube positioning and clamping mechanism (4) are installed on the base (5) in sequence, and a sliding groove structure that cooperates with the slide rail (5-1) on the base (5) is provided at the bottom of the head tube positioning and clamping mechanism (2), the upper and lower tube positioning and clamping mechanism (3), and the riser and five-way tube positioning and clamping mechanism (4).

2. The welding fixture for the front triangle of a bicycle frame with bent upper and lower tubes as described in claim 1, characterized in that: The upper and lower tube positioning and clamping mechanism (3) is provided with an L-shaped support frame (3-1), positioning blocks and upper and lower tube clamping clamp assembly (3-4); the horizontal seat and base (5) of the L-shaped support frame (3-1) are assembled in a detachable manner, an L-shaped support frame position adjustment slide (3-1-1) is provided on the bottom surface of the horizontal seat, at least two sets of vertical elongated holes (3-1-2) are arranged in parallel on the vertical wall of the L-shaped support frame (3-1), and at least two upper and lower positioning blocks are installed in the vertical elongated holes (3-1-2); the positioning blocks include an upper tube positioning block (3-2) and a lower tube positioning block (3-3); the upper and lower tube clamping clamp assembly (3-4) includes upper and lower parts, which are respectively fitted with different vertical elongated holes (3-1-2), wherein the upper part cooperates with the upper tube positioning block (3-2) to position and clamp the upper tube (1-2), and the lower part cooperates with the lower tube positioning block (3-3) to position and clamp the lower tube (1-5).

3. The welding fixture for the front triangle of a bicycle frame with bent upper and lower tubes according to claim 2, characterized in that: An arc groove matching the outer surface of the upper tube (1-2) is provided on the upper tube positioning block (3-2); an arc groove matching the outer surface of the lower tube (1-5) is provided on the lower tube positioning block (3-3).

4. The welding fixture for the front triangle of a bicycle frame with bent upper and lower tubes as described in claim 3, characterized in that: The riser and bottom bracket positioning and clamping mechanism (4) is provided with a U-shaped support frame (4-1), a bottom bracket positioning and clamping assembly (4-2), and a riser positioning and clamping assembly (4-3); the two vertical walls of the U-shaped support frame (4-1) are of unequal height, with the higher vertical wall located on the rear side. Several riser positioning and clamping assembly assembly holes (4-1-2) are provided on the higher vertical wall, and a U-shaped support frame positioning slide groove (4-1-1) is provided on the bottom surface of the U-shaped support frame (4-1). The bottom surface of the U-shaped support frame (4-1) is fixedly assembled with the base (5); the riser positioning and clamping assembly (4-3) includes a riser clamping clamp (4- 3-1) Riser clamp (4-3-2): The riser clamp (4-3-1) and riser clamp (4-3-2) are installed on the higher vertical wall of the U-shaped support frame (4-1) through the riser positioning clamp assembly assembly hole (4-1-2); The bottom pipe positioning clamp assembly (4-2) includes a bottom pipe positioning seat (4-2-1) and a bottom pipe pressing seat (4-2-2) arranged opposite to each other. The bottom pipe positioning seat (4-2-1) is installed on the higher vertical wall of the U-shaped support frame (4-1), and the bottom pipe pressing seat (4-2-2) is installed on the lower vertical wall of the U-shaped support frame (4-1).

5. The welding fixture for the front triangle of a bicycle frame with bent upper and lower tubes as described in claim 4, characterized in that: The head tube positioning and clamping mechanism (2) is provided with a head tube support frame (2-1), a head tube positioning support block assembly (2-2), and a head tube side push clamping assembly (2-3). The head tube support frame (2-1) is an inverted T-shaped bracket, and its horizontal seat and base (5) are assembled in a detachable manner. The bottom surface of the horizontal seat is provided with a head tube support frame position adjustment groove (2-1-1). The vertical wall of the T-shaped bracket is provided with an up-and-down position adjustment elongated hole (2-1-2) and several sets of head tube positioning support block assembly assembly holes (2-1-3). The head tube positioning support block assembly (2-2) is installed on the vertical wall of the T-shaped bracket. The head tube side push clamping assembly (2-3) is fitted with the head tube positioning support block assembly (2-2).

6. The welding fixture for the front triangle of a bicycle frame with bent upper and lower tubes as described in claim 4, characterized in that: The head tube positioning and clamping mechanism (2) is provided with a head tube support frame (2-1), a head tube positioning support block assembly (2-2), and a head tube side push clamping assembly (2-3). The head tube support frame (2-1) adopts an L-shaped bracket. The horizontal bottom surface of the L-shaped bracket is detachably assembled with the base (5). The horizontal bottom surface is provided with a head tube support frame position adjustment groove (2-1-1). The vertical wall of the L-shaped bracket is provided with an up-and-down position adjustment elongated hole (2-1-2) and several sets of head tube positioning support block assembly assembly holes (2-1-3). The head tube positioning support block assembly (2-2) is installed on the vertical wall of the L-shaped bracket. The head tube side push clamping assembly (2-3) is fitted with the head tube positioning support block assembly (2-2).

7. The welding fixture for the front triangle of a bicycle frame with bent upper and lower tubes as described in claim 5 or 6, characterized in that: The upper and lower pipe clamping clamp assembly (3-4), the head pipe side push clamping assembly (2-3), the riser clamping clamp (4-3-1), the riser lower clamping clamp (4-3-2), and the five-way pipe clamping seat (4-2-2) adopt a manual control structure.

8. The welding fixture for the front triangle of a bicycle frame with bent upper and lower tubes as described in claim 5 or 6, characterized in that: The upper and lower pipe clamping clamp assembly (3-4), the head pipe side push clamping assembly (2-3), the riser clamping clamp (4-3-1), the riser lower clamping clamp (4-3-2), and the five-way pipe clamping seat (4-2-2) adopt a pneumatic control structure.

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