A bicycle frame assembly welding tool with horizontal clamping of lower fork tube

Abstract

A kind of bicycle frame group welding tool of lower fork tube horizontal clamping, including front triangular component positioning clamping mechanism, upper and lower fork tube positioning clamping mechanism, ear piece positioning clamping mechanism and base;Five-way pipe positioning clamping assembly in the front triangular component positioning clamping mechanism is matched with base, the vertical pipe positioning clamping assembly is matched with five-way pipe positioning clamping assembly by pin shaft assembly, and is fixed by lock pin;Upper fork tube positioning clamping assembly and lower fork tube positioning assembly in the upper and lower fork tube positioning clamping mechanism are installed on support column, and the support column is matched with base;The height of ear piece positioning clamping assembly is consistent with lower fork tube positioning assembly and five-way pipe positioning clamping assembly, so that lower fork tube is clamped in horizontal state, ear piece positioning clamping assembly is assembled with support frame by front and back moving unit, and the support frame is matched with base.The utility model adopts above-mentioned technical means, reaches the purpose of reducing workpiece positioning clamping difficulty, improving work efficiency and welding product quality.

Description

Technical Field

[0001] This utility model relates to the field of bicycle production equipment technology, specifically a bicycle frame assembly welding fixture for horizontal clamping of the lower fork tube. Background Technology

[0002] As attached Figure 1 , Figure 2 As shown, a bicycle frame consists of a front triangle component 1 and a rear triangle component 2. The assembly and welding process for this bicycle frame is as follows: First, the front triangle component 1 is welded; then, the upper fork tube assembly (which includes two upper fork tubes 2-1 on the left and right sides and a short cross tube 2-4 connecting the upper fork tubes) in the rear triangle component 2 is welded; and finally, the lower fork tube 2-2 of the rear triangle component 2 is welded to the connection points of the two sets of lugs 2-3. Next, the seat tube 1-1 and bottom bracket tube 1-2 in the front triangle component 1 are welded to the upper fork tube assembly and lower fork tube 2-2 of the rear triangle component 2, respectively. Simultaneously, the upper fork tube assembly is welded to the connection points of the two sets of lugs 2-3, thus forming the bicycle frame assembly. According to the bicycle product assembly requirements, during the above-mentioned bicycle frame assembly and welding, the center distance L between the bottom bracket tube 1-2 of the front triangle component 1 and the rear axle mounting groove 2-3-1 on the lugs 2-3 of the rear triangle component 2 must be a set value.

[0003] In traditional bicycle frame welding fixtures, at least two sets of positioning and clamping mechanisms are set for the front triangle component 1. The riser 1-1 in the front triangle component 1 is usually clamped in a vertical state, and the workpiece is positioned with the bottom bracket 1-2 as the positioning reference. The upper fork assembly and lower fork 2-2 in the rear triangle component 2 are clamped at a set angle. Since the positioning reference needs to be changed during the clamping process of the upper fork assembly and lower fork 2-2, there is an error accumulation problem, which makes it difficult to guarantee the welding accuracy. Utility Model Content

[0004] This utility model provides a bicycle frame welding fixture for horizontal clamping of the lower fork tube. It achieves horizontal clamping and positioning of the lower fork tube through the cooperation of a front triangle component positioning and clamping mechanism, an upper and lower fork tube positioning and clamping mechanism, an ear plate positioning and clamping mechanism, and a base. Furthermore, an ear plate positioning seat that can move back and forth is provided in the ear plate positioning and clamping mechanism to facilitate the loading and unloading of workpieces, thereby reducing the difficulty of workpiece positioning and clamping, improving the efficiency of welding operations, and enhancing the quality of welded products.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A bicycle frame assembly welding fixture for horizontal clamping of the lower fork tube includes a front triangle component positioning and clamping mechanism, an upper and lower fork tube positioning and clamping mechanism, an ear piece positioning and clamping mechanism, and a base. The front triangular component positioning and clamping mechanism includes a bottom pipe positioning and clamping assembly and a riser positioning and clamping assembly. The bottom pipe positioning and clamping assembly is fitted with the base. The riser positioning and clamping assembly and the bottom pipe positioning and clamping assembly are assembled by a pin and fixed by a locking pin. The upper and lower fork tube positioning and clamping mechanism includes an upper fork tube positioning and clamping assembly, a lower fork tube positioning assembly, and a support column. Both the upper fork tube positioning and clamping assembly and the lower fork tube positioning assembly are mounted on the support column, and the support column is fitted with the base. The ear plate positioning and clamping mechanism includes an ear plate positioning and clamping assembly, a front and rear moving unit, and a support frame. The ear plate positioning and clamping assembly is at the same height as the lower fork tube positioning assembly and the five-way tube positioning and clamping assembly, so that the lower fork tube is clamped in a horizontal state. The ear plate positioning and clamping assembly is assembled with the support frame through the front and rear moving unit, and the support frame is fitted with the base.

[0006] The aforementioned bicycle frame welding fixture for horizontally clamping the lower fork tubes includes a lower fork tube positioning component of the upper and lower fork tube positioning and clamping mechanism. The lower fork tube positioning component comprises a first limiting post, a first limiting post front-to-back adjustment slider, a second limiting post, and a lower fork tube positioning seat. The lower fork tube positioning seat is a forward-extending cantilever beam structure, with its rear end assembled with the supporting column. The second limiting post and the first limiting post front-to-back position adjustment slider are mounted on the lower fork tube positioning seat. The first limiting post is installed on the first limiting post front-to-back position adjustment slider.

[0007] The above-mentioned bicycle frame assembly welding fixture with horizontal clamping of the lower fork tubes includes two parts, the first limiting post and the second limiting post, which are arranged symmetrically on the left and right sides. Each part is provided with two limiting post units for limiting the left and right lower fork tubes.

[0008] The aforementioned bicycle frame assembly welding fixture for horizontally clamping the lower fork tubes includes an upper fork tube positioning and clamping assembly comprising an upper fork tube limiting horizontal tube, an upper fork tube limiting horizontal tube front-to-back adjusting slider, an upper fork tube clamping clamp, and an upper fork tube positioning seat. The upper fork tube positioning seat is a forward-extending cantilever beam structure, with its rear end assembled to the support column. The upper fork tube limiting horizontal tube front-to-back adjusting slider is mounted on the upper fork tube positioning seat. The upper fork tube limiting horizontal tube is fixed on the upper fork tube limiting horizontal tube front-to-back adjusting slider, and baffles are provided at both ends of the upper fork tube limiting horizontal tube. The upper fork tube clamping clamp is mounted on the support column, located above the upper fork tube positioning seat, and is a downward-pressing clamping clamp with a horizontally arranged pressure bar as its downward pressing head.

[0009] The aforementioned bicycle frame assembly welding fixture for horizontal clamping of the lower fork tube includes an ear plate positioning and clamping mechanism comprising an ear plate clamping pliers and an ear plate clamping pliers mounting base. The ear plate clamping pliers mounting base has a symmetrical structure with two ear plate clamping bosses in its center and positioning pin holes on the ear plate clamping bosses. Two sets of ear plate clamping pliers are symmetrically arranged on the left and right sides and installed at the left and right ends of the ear plate clamping pliers mounting base. The two sets of ear plate clamping pliers are side-push clamping pliers with opposing clamping heads and positioning pins on their side clamping heads. The positioning pins can pass through the rear axle mounting groove on the ear plate and enter the positioning pin holes on the ear plate clamping bosses.

[0010] The above-mentioned bicycle frame assembly welding fixture for horizontal clamping of the lower fork tube includes a support frame for the lug positioning and clamping mechanism, which includes a support frame base and a U-shaped seat. The support frame base is an inverted T-shaped seat structure, with a U-shaped seat fixed at the top of its vertical wall, and a front-to-back moving unit mounted on the U-shaped seat.

[0011] The aforementioned bicycle frame assembly welding fixture with horizontal clamping of the lower fork tube includes a front-to-back moving unit for the lug positioning and clamping mechanism, comprising a driving element and a guiding element. The driving element is a side-push caliper mounted on the rear wall of the U-shaped seat, with the driving arm of the side-push caliper fixedly connected to the lug clamping caliper mounting base. The guiding element includes a slider and a guide post, with the guide post mounted on the side wall of the U-shaped seat and the slider fixed to the bottom of the clamping caliper mounting base.

[0012] The aforementioned bicycle frame assembly welding fixture for horizontal clamping of the lower fork tube includes a bottom bracket positioning and clamping assembly for the front triangle component positioning and clamping mechanism, comprising a U-shaped mounting base, a bottom bracket positioning seat, and a bottom bracket clamping clamp. The bottom surface of the U-shaped mounting base is assembled with the base, and the bottom bracket positioning seat is assembled on the inner side wall of the U-shaped mounting base. The bottom bracket clamping clamp is mounted on the outer side wall of the U-shaped mounting base and is a side-push clamping clamp, with its side pressure head arranged opposite to the bottom bracket positioning seat.

[0013] The aforementioned bicycle frame welding fixture for horizontal clamping of the lower fork tube includes a riser positioning and clamping assembly of the front triangle component positioning and clamping mechanism, comprising an angle adjustment seat, a riser positioning block, and a riser clamping clamp. The angle adjustment seat is hinged to the inner wall of the U-shaped mounting base of the bottom bracket positioning and clamping assembly. An arc-shaped elongated hole is provided on the angle adjustment seat, and a locking pin passing through the arc-shaped elongated hole is used to fix it to the inner wall of the U-shaped mounting base. The riser positioning block is fitted with the angle adjustment seat, and a riser clamping clamp is mounted on the riser positioning block. The riser clamping clamp is a side-pressure type clamping clamp, which clamps and fixes the riser through its side pressure head.

[0014] The aforementioned bicycle frame assembly welding fixture with horizontal clamping of the lower fork tube has a slide rail with a front-to-back through structure on the upper plane of the base along the central axis, and several sets of assembly holes on the left and right sides of the slide rail; the bottom surface of the U-shaped mounting seat in the front triangle component positioning and clamping mechanism, the bottom surface of the support column in the upper and lower fork tube positioning and clamping mechanism, and the bottom surface of the support frame in the lug positioning and clamping mechanism are all provided with slide grooves that cooperate with the base slide rail and elongated holes that cooperate with the assembly holes.

[0015] This utility model provides a bicycle frame welding fixture for horizontal clamping of the lower fork tube. Since the welding of the front triangle component is completed before the frame assembly welding, the front triangle component is treated as a single unit. Therefore, the bottom bracket positioning clamping assembly and the riser clamping assembly of the front triangle component positioning clamping mechanism can achieve the positioning and clamping effect on the front triangle component. The lug positioning clamping assembly of this utility model is at the same height as the lower fork tube positioning assembly and the bottom bracket tube positioning clamping assembly, ensuring that the lower fork tube is in a horizontal state after clamping. This is more conducive to ensuring that the center distance L between the bottom bracket tube and the rear axle mounting groove on the lug tube is the set value after the bicycle frame is welded. This utility model includes a front-to-back moving unit in the lug positioning clamping mechanism, which can be used during workpiece loading and unloading operations. The forward and backward moving unit drives the ear clamping clamp mounting base to move back and forth to avoid the ear piece welded to the rear end of the lower fork tube, making it easier to load and unload workpieces. This utility model has a slide rail on the base, with several sets of assembly holes on the left and right sides of the slide rail. Slide grooves and elongated holes are provided on the bottom surface of the U-shaped mounting base in the front triangular component positioning and clamping mechanism, the bottom surface of the support column in the upper and lower fork tube positioning and clamping mechanism, and the bottom surface of the support frame base in the ear piece positioning and clamping mechanism. Therefore, by adjusting the position of the U-shaped mounting base in the front triangular component positioning and clamping mechanism, the support column in the upper and lower fork tube positioning and clamping mechanism, and the support frame base in the ear piece positioning and clamping mechanism, it is possible to match welding workpieces of different specifications and sizes, thereby improving the versatility of this utility model. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the bicycle frame structure to which this utility model applies; Figure 2 yes Figure 1 K-direction view; Figure 3 This is a schematic diagram of the overall structure of this utility model; Figure 4 yes Figure 3 K-direction view; Figure 5 This is a schematic diagram of the positioning and clamping mechanism for the front triangular component; Figure 6 This is a schematic diagram of the upper and lower fork tube positioning and clamping mechanism; Figure 7 This is a schematic diagram of the ear piece positioning and clamping mechanism; Figure 8yes Figure 7 A schematic diagram after rotation around the vertical axis; Figure 9 This is a schematic diagram of the working state of this utility model; Figure 10 yes Figure 9 The K-direction view.

[0017] Explanation of each label in the diagram: 1 is the front triangle component, 1-1 is the riser, and 1-2 is the bottom bracket. 2 is the rear triangle component, 2-1 is the upper fork tube, 2-2 is the lower fork tube, 2-3 is the lug, 2-3-1 is the rear axle mounting groove, and 2-4 is the upper fork tube connecting to the short cross tube. 3 is the positioning and clamping mechanism for the front triangular component. 3-1 is the bottom bracket positioning and clamping assembly; 3-1-1 is the U-shaped mounting base; 3-1-2 is the bottom bracket clamping pliers; 3-1-3 is the bottom bracket positioning seat. 3-2 is a locking pin 3-3 is the riser positioning and clamping assembly, 3-3-1 is the angle adjustment seat, 3-3-1-1 is the arc-shaped elongated hole, 3-3-2 is the riser clamping clamp, and 3-3-3 is the riser positioning block; 4 is the positioning and clamping mechanism for the upper and lower fork tubes. 4-1 is the supporting column 4-2 is the lower fork tube positioning assembly; 4-2-1 is the first limiting post; 4-2-2 is the slider for adjusting the front and rear positions of the first limiting post; 4-2-3 is the second limiting post; and 4-2-4 is the lower fork tube positioning seat. 4-3 is the upper fork tube positioning and clamping assembly, 4-3-1 is the upper fork tube limiting horizontal tube, 4-3-2 is the upper fork tube limiting horizontal tube front and rear adjustment slider, 4-3-3 is the upper fork tube positioning seat, and 4-3-4 is the upper fork tube clamping clamp. 5 is the ear plate positioning and clamping mechanism. 5-1 is the support frame, 5-1-1 is the support frame base, and 5-1-2 is the U-shaped base. 5-2 is the ear piece positioning and clamping assembly; 5-2-1 is the ear piece clamping clamp mounting base; 5-2-2 is the ear piece clamping clamp; 5-2-3 is the ear piece clamping boss. 5-3 is the forward and backward moving unit, 5-3-1 is the side-push caliper, 5-3-2 is the guide post, and 5-3-3 is the slider; 6 is the base, 6-1 is the slide rail, and 6-2 is the mounting hole. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0019] See Figure 1. Figure 2A bicycle frame is composed of a front triangle component 1 and a rear triangle component 2. The assembly and welding process of the bicycle frame is as follows: First, the front triangle component 1 is welded, the upper fork tube assembly (including the left and right upper fork tubes 2-1 and the short cross tubes 2-4 connecting the upper fork tubes) in the rear triangle component 2 is welded, and the lower fork tube 2-2 of the rear triangle component 2 is welded to the connection parts of the two sets of lugs 2-3. Then, the upper fork tube assembly and lower fork tube 2-2 of the front triangle component 1 and the rear triangle component 2 are welded together, and the connection parts of the upper fork tube assembly and the two sets of lugs 2-3 are welded together, thereby forming the bicycle frame assembly.

[0020] See Figure 3 , Figure 4 To reduce the difficulty of workpiece positioning and clamping, improve welding efficiency and welded product quality, this utility model provides a bicycle frame welding fixture for horizontal clamping of the lower fork tube. It includes a front triangle component positioning and clamping mechanism 3, an upper and lower fork tube positioning and clamping mechanism 4, an ear piece positioning and clamping mechanism 5, and a base 6. The front triangle component positioning and clamping mechanism 3, the upper and lower fork tube positioning and clamping mechanism 4, and the ear piece positioning and clamping mechanism 5 are fitted to the base 6. A slide rail 6-1 with a through-type structure is provided on the upper surface of the base 6 along its central axis, and several sets of mounting holes 6-2 are provided on the left and right sides of the slide rail 6-1. The front triangle component positioning and clamping mechanism 3, the upper and lower fork tube positioning and clamping mechanism 4, and the ear piece positioning and clamping mechanism 5 can move back and forth along the slide rail 6-1 on the base 6, and achieve precise position adjustment and locking fixation through elongated holes that mate with the mounting holes 6-2 on the base 6.

[0021] See Figure 3 , Figure 4 , Figure 5The bicycle frame welding fixture for horizontal clamping of the lower fork tube described in this utility model includes a front triangle component positioning and clamping mechanism 3 comprising a bottom bracket positioning and clamping assembly 3-1 and a riser positioning and clamping assembly 3-3. The bottom bracket positioning and clamping assembly 3-1 includes a U-shaped mounting base 3-1-1, a bottom bracket positioning seat 3-1-3, and a bottom bracket clamping clamp 3-1-2. The bottom surface of the U-shaped mounting base 3-1-1 is assembled with the base 6, and the bottom bracket positioning seat 3-1-3 is assembled on the inner side wall of the U-shaped mounting base 3-1-1. The bottom bracket clamping clamp 3-1-2 is mounted on the outer side wall of the U-shaped mounting base 3-1-1 and is a side-push clamping clamp, with its side pressure head arranged opposite to the bottom bracket positioning seat 3-1-3. The riser positioning and clamping assembly 3-3 includes an angle adjustment seat 3-3-1, a riser positioning block 3-3-3, and a riser clamping clamp 3-3-2. The angle adjustment seat 3-3-1 is hinged to the inner wall of the U-shaped mounting seat 3-1-1 of the five-way pipe positioning and clamping assembly 3-1. An arc-shaped elongated hole 3-3-1-1 is provided on the angle adjustment seat 3-3-1, and it is fixed to the inner wall of the U-shaped mounting seat 3-1-1 by a locking pin 3-2 passing through the arc-shaped elongated hole 3-3-1-1. The riser positioning block 3-3-3 is fitted with the angle adjustment seat 3-3-1. A positioning groove matching the outer surface of the riser 1-1 is provided on the riser positioning block 3-3-3, and the riser clamping clamp 3-3-2 is mounted on the riser positioning block 3-3-3. The riser clamping clamp 3-3-2 is a side-pressure type clamping clamp, which clamps and fixes the side wall of the riser 1-1 through its side pressure head.

[0022] See Figure 3 , Figure 4 , Figure 6 The bicycle frame assembly welding fixture for horizontal clamping of the lower fork tube described in this utility model includes an upper fork tube positioning and clamping component 4-3, a lower fork tube positioning component 4-2, and a support column 4-1. The lower fork tube positioning assembly 4-2 includes a first limiting post 4-2-1, a first limiting post front-to-back position adjustment slider 4-2-2, a second limiting post 4-2-3, and a lower fork tube positioning seat 4-2-4. The lower fork tube positioning seat 4-2-4 is a cantilever beam structure extending forward, with its rear end assembled with the support column 4-1. The second limiting post 4-2-3 and the first limiting post front-to-back position adjustment slider 4-2-2 are mounted on the lower fork tube positioning seat 4-2-4. The first limiting post 4-2-1 is mounted on the first limiting post front-to-back position adjustment slider 4-2-2. The first limiting post 4-2-1 and the second limiting post 4-2-3 each include two parts arranged symmetrically on the left and right sides, and each part is provided with two limiting post units that limit the left and right lower fork tubes 2-2.

[0023] See also Figure 3 , Figure 4 , Figure 6The bicycle frame welding fixture for horizontal clamping of the lower fork tube described in this utility model includes an upper fork tube positioning and clamping assembly 4-3 comprising an upper fork tube limiting horizontal tube 4-3-1, an upper fork tube limiting horizontal tube front and rear adjusting slider 4-3-2, an upper fork tube clamping clamp 4-3-4, and an upper fork tube positioning seat 4-3-3. The upper fork tube positioning seat 4-3-3 is a forward-extending cantilever beam structure, with its rear end assembled with the supporting column 4-1. The tube positioning seat 4-3-3 is equipped with an upper fork tube limiting horizontal tube front and rear adjustment slider 4-3-2; the upper fork tube limiting horizontal tube 4-3-1 is fixed on the upper fork tube limiting horizontal tube front and rear adjustment slider 4-3-2, and baffles are provided at both ends of the upper fork tube limiting horizontal tube 4-3-1; the upper fork tube clamping pliers 4-3-4 are installed on the support column 4-1, located above the upper fork tube positioning seat 4-3-3, and are downward clamping pliers, with the downward clamping head being a horizontally arranged clamping rod.

[0024] See Figure 3 , Figure 4 , Figure 7 , Figure 8 The bicycle frame welding fixture for horizontal clamping of the lower fork tube described in this utility model has an ear plate positioning and clamping mechanism 5, which includes an ear plate positioning and clamping component 5-2, a front and rear moving unit 5-3, and a support frame 5-1. The ear plate positioning and clamping component 5-2 is at the same height as the lower fork tube positioning component 4-2 and the bottom bracket tube positioning and clamping component 3-1, thereby enabling the lower fork tube 2-2 to be clamped in a horizontal state. The ear piece positioning and clamping assembly 5-2 includes an ear piece clamping pliers 5-2-2 and an ear piece clamping pliers mounting base 5-2-1. The ear piece clamping pliers mounting base 5-2-1 has a symmetrical structure, with two upwardly extending ear piece clamping bosses 5-2-3 in its middle. Positioning pin holes are provided on the ear piece clamping bosses 5-2-3. Two sets of ear piece clamping pliers 5-2-2 are arranged symmetrically on the left and right sides and installed at the left and right ends of the ear piece clamping pliers mounting base 5-2-1. The two sets of ear piece clamping pliers 5-2-2 are side-push clamping pliers with opposite clamping heads. Positioning pins are provided on their side clamping heads. The positioning pins can pass through the rear axle mounting groove 2-3-1 on the ear piece 2-3 and enter the positioning pin holes on the ear piece clamping bosses 5-2-3. The ear piece 2-3 can be positioned by the positioning pins, and then the ear piece 2-3 can be clamped and fixed by the side clamping heads of the ear piece clamping pliers 5-2-2. The support frame 5-1 includes a support frame base 5-1-1 and a U-shaped seat 5-1-2. The support frame base 5-1-1 is an inverted T-shaped seat structure, and the U-shaped seat 5-1-2 is fixed at the top of its vertical wall. A front and rear moving unit 5-3 is mounted on the U-shaped seat 5-1-2. The forward and backward moving unit 5-3 includes a driving element and a guiding element. The driving element is a side-push caliper 5-3-1, and the driving arm of the side-push caliper 5-3-1 is fixedly connected to the ear clamping caliper mounting base 5-2-1. The guiding element includes a slider 5-3-3 and a guide post 5-3-2. The guide post 5-3-2 is installed on the side wall of the U-shaped seat 5-1-2, and the slider 5-3-3 is fixed to the bottom of the clamping caliper mounting base 5-2-1.

[0025] See Figures 1 to 10When performing the first-piece welding operation on a certain batch of bicycle frames using this utility model, firstly, adjust the relative assembly positions of the front triangle component positioning clamping mechanism 3, the upper and lower fork tube positioning clamping mechanism 4, the lug positioning clamping mechanism 5, and the base 6 according to the size and specifications of the workpiece to be welded. Adjust the positional relationship between the riser positioning clamping component 3-3 and the bottom bracket positioning clamping component 3-1 in the front triangle component positioning clamping mechanism 3 (including the height position of the riser positioning block 3-3-3, and the angle between the angle adjustment seat 3-3-1 and the U-shaped mounting seat 3-1-1). Adjust the height of the lower fork tube positioning seat 4-2-4 in the upper and lower fork tube positioning clamping mechanism 4 so that the lug positioning clamping component 5-2 is aligned with the lower fork tube positioning component 4-2 and the bottom bracket. The height of the pipe positioning clamping assembly 3-1 is consistent. Adjust the upper fork pipe positioning seat 4-3-3 in the upper and lower fork pipe positioning clamping mechanism 4 to a suitable position. Through the above adjustment, the center distance L between the bottom bracket 1-2 of the front triangle component 1 and the rear axle mounting groove 2-3-1 on the lug 2-3 of the rear triangle component 2 meets the set value requirement, thus completing the adjustment of the positions of each component of this utility model. Then, the lug positioning clamping assembly 5-2 is moved backward by the front and rear moving unit 5-3 in the lug positioning clamping mechanism 5 to avoid the lug 2-3, which is welded to the lower fork pipe 2-2 when the workpiece is loaded. The front triangle component 1 is placed in the position of the front triangle component positioning clamping mechanism 3. The bottom bracket positioning clamping assembly 3-1 is used to clamp the front triangle component 1. The two ends of the five-way tube 1-2 of component 1 are pressed together. The riser tube 1-2 of the front triangle component 1 is pressed together by the riser tube pressing assembly 3-3. At this time, the front triangle component 1 is fixed. Then, the lower fork tube 2-2 of the rear triangle component 2 is placed on the lower fork tube positioning assembly 4-2 of the upper and lower fork tube positioning clamping mechanism 4. The ear plate positioning clamping mechanism 5 is driven to move forward by the forward and backward moving unit 5-3 in the ear plate positioning clamping mechanism 5. The ear plate clamping pliers 5-2-2 are operated. The positioning pin set on the pressure head passes through the positioning pin hole on the ear plate 2-3 and the ear plate clamping boss 5-2-3 to position the ear plate 2-3. Then, the pressure head of the ear plate clamping pliers 5-2-2 clamps and fixes the ear plate 2-3. The upper fork tube assembly rear end slot (upper fork tube assembly) is then fixed. After assembly welding, slots for mating with lugs 2-3 are made at the rear ends of the left and right rear fork tubes 2-2, and the lugs 2-3 are inserted into the left and right lugs 2-3 respectively. The front end of the upper fork tube assembly is mounted on the upper fork tube limiting cross tube 4-3-1. The upper fork tube clamping clamp 4-3-4 is closed, and the clamping rods arranged laterally on the clamping head of the upper fork tube clamping clamp 4-3-4 clamp the left and right upper fork tubes 2-1 tightly. Measure whether the center distance L between the bottom bracket 1-2 of the front triangle component 1 and the rear axle mounting groove 2-3-1 on the lugs 2-3 of the rear triangle component 2 meets the set value requirement. If L meets the set value requirement, the welding operation begins. If L does not meet the set value requirement, the above adjustment process is repeated until L meets the set value requirement, and the welding operation is performed.The base 6 of this invention can be connected to the output shaft of the indexing machine at the welding station. During the welding process, after the welding operation on one side of the workpiece is completed, the indexing machine at the welding station rotates the invention and the workpiece 180 degrees to begin the welding process on the other side of the workpiece, thus meeting the full welding process requirements of the welding area. After completing the first welding operation of a batch of bicycle frames, and after the product is inspected and found to meet the relevant parameter requirements, mass production can begin using this invention.

Claims

1. A welding fixture for horizontally clamping the lower fork tube of a bicycle frame, characterized in that: It includes a front triangle component positioning and clamping mechanism (3), an upper and lower fork tube positioning and clamping mechanism (4), an ear plate positioning and clamping mechanism (5), and a base (6). The front triangular component positioning and clamping mechanism (3) includes a five-way pipe positioning and clamping assembly (3-1) and a riser positioning and clamping assembly (3-3). The five-way pipe positioning and clamping assembly (3-1) is fitted with the base (6). The riser positioning and clamping assembly (3-3) and the five-way pipe positioning and clamping assembly (3-1) are assembled by a pin and fixed by a locking pin (3-2). The upper and lower fork tube positioning and clamping mechanism (4) includes an upper fork tube positioning and clamping assembly (4-3), a lower fork tube positioning assembly (4-2), and a support column (4-1). The upper fork tube positioning and clamping assembly (4-3) and the lower fork tube positioning assembly (4-2) are both installed on the support column (4-1), and the support column (4-1) is fitted with the base (6). The ear piece positioning and clamping mechanism (5) is provided with an ear piece positioning and clamping assembly (5-2), a front and rear moving unit (5-3), and a support frame (5-1). The ear piece positioning and clamping assembly (5-2) is at the same height as the lower fork tube positioning assembly (4-2) and the five-way tube positioning and clamping assembly (3-1), so that the lower fork tube (2-2) is clamped in a horizontal state. The ear piece positioning and clamping assembly (5-2) is assembled with the support frame (5-1) through the front and rear moving unit (5-3). The support frame (5-1) is fitted with the base (6).

2. The bicycle frame assembly welding fixture for horizontal clamping of the lower fork tube according to claim 1, characterized in that: The lower fork tube positioning assembly (4-2) of the upper and lower fork tube positioning and clamping mechanism (4) includes a first limiting post (4-2-1), a first limiting post front and rear position adjustment slider (4-2-2), a second limiting post (4-2-3), and a lower fork tube positioning seat (4-2-4). The lower fork tube positioning seat (4-2-4) is a cantilever beam structure extending forward, and its rear end is assembled with the support column (4-1). The second limiting post (4-2-3) and the first limiting post front and rear position adjustment slider (4-2-2) are mounted on the lower fork tube positioning seat (4-2-4). The first limiting post (4-2-1) is mounted on the first limiting post front and rear position adjustment slider (4-2-2).

3. The bicycle frame assembly welding fixture for horizontal clamping of the lower fork tube according to claim 2, characterized in that: The first limiting post (4-2-1) and the second limiting post (4-2-3) each include two parts arranged symmetrically on the left and right sides. In each part, two limiting post units are respectively set to limit the left and right lower fork tubes (2-2).

4. The bicycle frame assembly welding fixture for horizontal clamping of the lower fork tube according to claim 3, characterized in that: The upper fork tube positioning and clamping assembly (4-3) of the upper and lower fork tube positioning and clamping mechanism (4) includes an upper fork tube limiting horizontal tube (4-3-1), an upper fork tube limiting horizontal tube front and rear adjusting slider (4-3-2), an upper fork tube clamping clamp (4-3-4), and an upper fork tube positioning seat (4-3-3); the upper fork tube positioning seat (4-3-3) is a forward-extending cantilever beam structure, the rear end of which is assembled with the supporting column (4-1), and a fixture is mounted on the upper fork tube positioning seat (4-3-3). Install the fork tube limiting horizontal tube front and rear adjustment slider (4-3-2); the upper fork tube limiting horizontal tube (4-3-1) is fixed on the upper fork tube limiting horizontal tube front and rear adjustment slider (4-3-2), and baffles are provided at both ends of the upper fork tube limiting horizontal tube (4-3-1); the upper fork tube clamping pliers (4-3-4) are installed on the support column (4-1), located above the upper fork tube positioning seat (4-3-3), and are downward clamping pliers, with the downward clamping head being a horizontally arranged clamping rod.

5. The bicycle frame assembly welding fixture for horizontal clamping of the lower fork tube according to claim 4, characterized in that: The ear-piece positioning and clamping mechanism (5) includes an ear-piece clamping pliers (5-2-2) and an ear-piece clamping pliers mounting base (5-2-1). The ear-piece clamping pliers mounting base (5-2-1) is a left-right symmetrical structure, with two ear-piece clamping bosses (5-2-3) in the middle, and positioning pin holes on the ear-piece clamping bosses (5-2-3). Two sets of ear-piece clamping pliers (5-2-2) are arranged symmetrically on the left and right sides and installed at the left and right ends of the ear-piece clamping pliers mounting base (5-2-1). The two sets of ear-piece clamping pliers (5-2-2) are side-push clamping pliers with opposite clamping heads, and positioning pins are provided on their side clamping heads. The positioning pins can pass through the rear axle assembly groove (2-3-1) on the ear-piece (2-3) and enter the positioning pin holes on the ear-piece clamping bosses (5-2-3).

6. The bicycle frame assembly welding fixture for horizontal clamping of the lower fork tube according to claim 5, characterized in that: The support frame (5-1) of the ear positioning and clamping mechanism (5) includes a support frame base (5-1-1) and a U-shaped seat (5-1-2); the support frame base (5-1-1) is an inverted T-shaped seat structure, and the U-shaped seat (5-1-2) is fixed at the top of its vertical wall, and a front and rear moving unit (5-3) is mounted on the U-shaped seat (5-1-2).

7. The bicycle frame assembly welding fixture for horizontal clamping of the lower fork tube according to claim 6, characterized in that: The forward and backward moving unit (5-3) includes a driving element and a guiding element; the driving element is a side-push caliper (5-3-1) mounted on the rear side wall of the U-shaped seat (5-1-2), and the driving arm of the side-push caliper (5-3-1) is fixedly connected to the ear clamping caliper mounting base (5-2-1); the guiding element includes a slider (5-3-3) and a guide post (5-3-2), the guide post (5-3-2) is mounted on the side wall of the U-shaped seat (5-1-2), and the slider (5-3-3) is fixed to the bottom of the clamping caliper mounting base (5-2-1).

8. The bicycle frame assembly welding fixture for horizontal clamping of the lower fork tube according to claim 4, characterized in that: The five-way pipe positioning and clamping assembly (3-1) of the front triangular component positioning and clamping mechanism (3) includes a U-shaped mounting base (3-1-1), a five-way pipe positioning base (3-1-3), and a five-way pipe clamping clamp (3-1-2). The bottom surface of the U-shaped mounting base (3-1-1) is assembled with the base (6), and the five-way pipe positioning base (3-1-3) is assembled on the inner side wall of the U-shaped mounting base (3-1-1). The five-way pipe clamping clamp (3-1-2) is installed on the outer side wall of the U-shaped mounting base (3-1-1) and is a side-push clamping clamp. Its side pressure head is arranged opposite to the five-way pipe positioning base (3-1-3).

9. The bicycle frame assembly welding fixture for horizontal clamping of the lower fork tube according to claim 8, characterized in that: The riser positioning and clamping assembly (3-3) of the front triangular component positioning and clamping mechanism (3) includes an angle adjustment seat (3-3-1), a riser positioning block (3-3-3), and a riser clamping clamp (3-3-2); the angle adjustment seat (3-3-1) is hinged to the inner wall of the U-shaped mounting seat (3-1-1) of the five-way pipe positioning and clamping assembly (3-1), and an arc-shaped elongated hole (3-3-1-1) is provided on the angle adjustment seat (3-3-1). The riser is fixed to the inner wall of the U-shaped mounting base (3-1-1) by a locking pin (3-2) passing through the arc-shaped elongated hole (3-3-1-1); the riser positioning block (3-3-3) is fitted with the angle adjustment seat (3-3-1), and the riser clamping pliers (3-3-2) are mounted on the riser positioning block (3-3-3); the riser clamping pliers (3-3-2) are side-pressure type clamping pliers, which clamp and fix the riser (1-1) by its side pressure head.

10. The bicycle frame assembly welding fixture for horizontal clamping of the lower fork tube according to claim 8, characterized in that: The upper surface of the base (6) is provided with a slide rail (6-1) with a front-to-back through structure along the central axis, and several sets of assembly holes (6-2) are provided on the left and right sides of the slide rail (6-1); the bottom surface of the U-shaped mounting seat (3-1-1) in the front triangular component positioning and clamping mechanism (3), the bottom surface of the support column (4-1) in the upper and lower fork tube positioning and clamping mechanism (4), and the bottom surface of the support frame (5-1) in the ear plate positioning and clamping mechanism (5) are all provided with a sliding groove that cooperates with the slide rail (6-1) on the base (6) and an elongated hole that cooperates with the assembly hole (6-2).

Images