Welding tool for upper fork and lower fork of rear triangle of bicycle frame
By designing an adjustable rear triangle upper fork and lower fork welding tooling for bicycle frames, the positioning and compression problems of bicycle frames of different specifications and models in bicycle production are solved, reducing production costs and management difficulties.
Patent Information
- Application Number
- CN202422297454.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-20
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-09-20
AI Technical Summary
Bicycle frames of different specifications and models in bicycle production require special welding tooling, which leads to high production auxiliary costs and difficult management.
A bicycle frame rear triangle upper fork and lower fork welding tooling is designed, including a base plate, a positioning device and a compression device. The adjustable positioning device and a compression device meet the positioning and compression needs of bicycle frames of different specifications and models, and reduce the types and quantity of welding tooling.
It reduces the auxiliary cost of bicycle production and the difficulty of production site management, and realizes efficient welding positioning and compression of bicycle frames of different specifications and models.
Smart Images
Figure CN223070808U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a welding tool for a bicycle frame, in particular to a welding tool for the upper fork and the lower fork of the rear triangle of a bicycle frame. Background Art
[0002] In modern people's lives, bicycles, as a means of green travel, are increasingly loved by people. In order to meet people's different living needs, bicycle manufacturers produce bicycles of different specifications and models, such as adult bicycles, children's bicycles, mountain bikes, road bikes, and so on. The bicycle frame is an important part of a bicycle and is welded from frame parts in a production workshop. In order to ensure the smooth progress of welding operations and welding quality, it is often necessary to use a welding tool to position and clamp the frame parts before welding the bicycle frame. Because there are many specifications and models of bicycles, the bicycle frames are also diverse, with different shapes, sizes, and dimensions. Each specification and model of bicycle frame corresponds to its own dedicated welding tool, which not only results in high auxiliary costs for bicycle production but also causes difficulties in production site management. Content of the Utility Model
[0003] The utility model provides a welding tool for the upper fork and the lower fork of the rear triangle of a bicycle frame, aiming to optimize the design of the structure of the dedicated welding tool for the bicycle frame so that it can match bicycle frames of different specifications and models, achieving the purpose of reducing the auxiliary costs of bicycle production and the difficulty of production site management.
[0004] To achieve the above object, the utility model adopts the following technical solutions:
[0005] A welding tool for the upper fork and the lower fork of the rear triangle of a bicycle frame includes a bottom plate, a positioning device, and a pressing device. The bottom plate is detachably and fixedly connected to a welding workbench. The positioning device and the pressing device are both symmetrically arranged on the bottom plate with respect to the A-A center line. The position of the positioning device relative to the bottom plate in the front, back, left, and right directions is adjustable and it is detachably and fixedly connected to the bottom plate. The pressing device is adapted to the position of the positioning device and is detachably and fixedly connected to the bottom plate. After the frame parts to be welded are positioned according to the designed dimensions by the positioning device, the corresponding frame parts are pressed and fixed by the pressing device.
[0006] In the above-mentioned welding tool for the upper fork and the lower fork of the rear triangle of a bicycle frame, multiple groups of positioning threaded holes are provided on the bottom plate, which are suitable for the fixed connection of the positioning device and the pressing device at each working position.
[0007] The above-mentioned welding tooling for the upper and lower forks of the rear triangle of the bicycle frame, the positioning device includes a front positioning seat, a first positioning support, a second positioning support, a third positioning support, and a rear positioning seat arranged in sequence from front to back along the A-A center line direction, and the pressing device includes a pressing head adapted to the positioning device and a control mechanism for controlling the opening and closing of the pressing head.
[0008] The above-mentioned welding tooling for the upper and lower forks of the rear triangle of the bicycle frame, the control mechanism includes a vertical quick clamp and a push-pull quick clamp. The front positioning seat, the first positioning support, the second positioning support, and the third positioning support are matched with the vertical quick clamp, and the rear positioning seat is matched with the push-pull quick clamp.
[0009] The above-mentioned welding tooling for the upper and lower forks of the rear triangle of the bicycle frame, the front positioning seat is provided with a rear vertical surface perpendicular to the upper surface of the bottom plate, the rear positioning seat is provided with a front vertical surface perpendicular to the upper surface of the bottom plate, and the left and right side vertical surfaces of the rear positioning seat respectively extend vertically left and right to extend out earpiece positioning columns adapted to the earpieces. The extending length of the earpiece positioning columns is adjustable, and the extending end of the earpiece positioning column is provided with an axial positioning shoulder section adapted to the earpiece and with a length not greater than the thickness of the earpiece. The first positioning support, the second positioning support, and the third positioning support are all provided with a pair of positioning pieces. Each pair of positioning pieces is symmetrically arranged along the A-A center line. The positioning pieces are provided with positioning grooves matching the corresponding bicycle frame parts. The positioning pieces are provided with oblong holes one. A plurality of threaded connection holes matching the oblong holes one are provided on the front and back surfaces of the first positioning support and the third positioning support and on the left and right surfaces of the second positioning support. The middle part of the front vertical surface of the second positioning support vertically extends forward to extend out a positioning groove plate adapted to the vertical edge of the rear tile support.
[0010] Before welding the rear triangle lower fork of the bicycle frame, rotate the lug positioning post, adjust the length of the protruding end of the lug positioning post to a suitable position, hook the left and right lugs on the positioning shoulder section respectively, adjust the front and rear positions of the first positioning support and the third positioning support and the left and right positions of the positioning pieces thereon to suitable positions, place the two lower fork tubes in the positioning grooves of the positioning pieces respectively, adjust the front and rear positions of the front positioning seat and the rear positioning seat on the bottom plate, make the front end of the lower fork tube abut against the rear vertical surface on the front positioning seat, insert the tail of the lower fork tube into the lug, adjust the front and rear position of the second positioning support to a suitable position, insert the vertical plate of the rear fender support into the positioning groove plate of the second positioning support, and place the connecting plate of the rear fender support on the two lower fork tubes, and the above operations complete the positioning before welding the rear triangle lower fork of the above bicycle frame; before welding the rear triangle upper fork of the bicycle frame, adjust the front and rear positions of the first positioning support and the third positioning support and the left and right positions of the positioning pieces thereon to suitable positions, place the two upper fork tubes in the positioning grooves of the positioning pieces respectively, adjust the front and rear positions of the front positioning seat and the rear positioning seat on the bottom plate, make the front end of the upper fork tube abut against the rear vertical surface on the front positioning seat, make the tail of the upper fork tube abut against the front vertical surface of the rear positioning seat, adjust the front and rear position of the second positioning support to a suitable position, and place the short cross tube in the positioning groove of the positioning piece of the second positioning support, and the above operations complete the positioning before welding the rear triangle upper fork of the above bicycle frame.
[0011] The above-mentioned welding tooling for the upper and lower forks of the rear triangle of a bicycle frame. The basic shape of the front positioning seat is L-shaped, including a vertical plate and a connecting plate. Two long circular holes II are arranged on the connecting plate corresponding to the positioning threaded holes at the front of the bottom plate. A mounting seat I extends vertically upward from the middle of the connecting plate. A vertical quick clamp I is fixedly connected to the mounting seat I. The vertical quick clamp I controls the pressing head to press and fix the front section of the upper fork tube or the lower fork tube of the rear triangle of the bicycle frame at the positioning support I. A vertical quick clamp II is fixedly connected to the upper part of the positioning support II. The vertical quick clamp II controls the pressing head to press and fix the rear tile support or the short cross tube. An installation seat III detachably and fixedly connected to the bottom plate is arranged at the front of the positioning support III. The installation seat III is adapted to the positioning threaded holes in the middle and rear parts of the bottom plate. A vertical quick clamp III is fixedly connected to the top of the installation seat III. The vertical quick clamp III controls the pressing head to press and fix the rear sections of the upper fork tube and the lower fork tube at the positioning support III. Rear installation seats are symmetrically arranged on the left and right sides of the rear positioning seat. The rear installation seats are detachably and fixedly connected to the bottom plate. The rear installation seats are adapted to two groups of the positioning threaded holes at the rear of the bottom plate. The push-pull type quick clamps are symmetrically fixedly connected to the two rear installation seats. The push-pull type quick clamps control the pressing head to press and fix the ear piece sleeved on the positioning shoulder section.
[0012] For the above-mentioned welding tooling for the upper and lower forks of the rear triangle of a bicycle frame, the positioning groove of the positioning piece is a U-shaped groove.
[0013] The utility model relates to a welding tooling for the upper and lower forks of the rear triangle of a bicycle frame. By adjusting the front and rear positions of the front positioning seat and the rear positioning seat on the bottom plate, the front and rear direction positioning requirements of the upper fork tube and the lower fork tube of the rear triangle of a bicycle frame with different length dimensions can be met. By adjusting the left and right positions of the positioning pieces on the positioning support I and the positioning support III, the left and right direction positioning requirements of the upper fork tube and the lower fork tube of the rear triangle of a bicycle frame with different widths can be met. By adjusting the front and rear positions of the positioning support II on the bottom plate, the front and rear direction positioning requirements of the rear tile support of the lower fork of the rear triangle of a bicycle frame with different specifications or the short cross tube of the upper fork of the rear triangle of a bicycle frame can be met. Before welding the upper and lower forks of the rear triangle of a bicycle frame with different specifications, only the connection screws at the corresponding parts of the positioning device and the pressing device need to be loosened, and the positions of the positioning device and the pressing device on the bottom plate can be adjusted, without having to replace the entire welding tooling for the upper and lower forks of the rear triangle of a bicycle frame. Since the types and quantities of the welding tooling in bicycle production are reduced, the auxiliary cost of bicycle production is reduced and the difficulty of production site management is lowered, solving the problems of high auxiliary cost of bicycle production and great difficulty of production site management. Description of the Drawings
[0014] Figure 1 is the structural schematic diagram of the present utility model (when welding the lower fork tube);
[0015] Figure 2 is Figure 1 the top view of;
[0016] Figure 3 is Figure 1 the front view of;
[0017] Figure 4 is Figure 3 the partial enlarged view of area H in;
[0018] Figure 5 is Figure 1 the right view of;
[0019] Figure 6 is Figure 2 the structural schematic diagram of the B - B section in;
[0020] Figure 7 is the front view of the present utility model (when welding the upper fork tube);
[0021] Figure 8 is the structural schematic diagram of the positioning piece.
[0022] The list of each label in the figure is as follows:
[0023] 1. Base plate, 1 - 1. Positioning threaded hole, 2. Positioning device, 2 - 1. Front positioning seat, 2 - 11. Vertical plate, 2 - 111. Rear vertical surface, 2 - 12. Connecting plate, 2 - 121. Second oblong hole, 2 - 13. First mounting seat, 2 - 2. First positioning support, 2 - 21. Positioning piece, 2 - 211. Positioning groove, 2 - 212. First oblong hole, 2 - 22. Threaded connection hole, 2 - 3. Second positioning support, 2 - 31. Positioning groove plate, 2 - 4. Third positioning support, 2 - 5. Rear positioning seat, 2 - 51. Front vertical surface, 2 - 52. Ear piece positioning column, 2 - 53. Positioning shoulder section, 3. Pressing device, 3 - 1. Operating mechanism, 3 - 11. Vertical quick clamp, 3 - 111. First vertical quick clamp, 3 - 112. Second vertical quick clamp, 3 - 113. Third vertical quick clamp, 3 - 12. Push - pull quick clamp, 3 - 2. Pressing head, 3 - 3. Rear mounting seat;
[0024] The following are the parts to be welded and assembled: 101. Ear piece, 102. Rear tile support, 102 - 1. Vertical plate, 103. Upper fork tube, 104. Lower fork tube, 105. Short cross tube. Specific embodiments
[0025] The present utility model will be further described below with reference to the accompanying drawings and specific embodiments.
[0026] Refer to Figure 1, Figure 2 , Figure 3 , an embodiment of the present utility model provides a welding tooling for the upper fork and lower fork of the rear triangle of a bicycle frame, including a bottom plate 1, a positioning device 2 and a pressing device 3. The bottom plate 1 is detachably and fixedly connected to a welding workbench. The positioning device 2 and the pressing device 3 are symmetrically arranged on the bottom plate 1 with respect to the A-A center line. The front, rear, left and right positions of the positioning device 2 relative to the bottom plate 1 are adjustable and it is detachably and fixedly connected to the bottom plate 1. The pressing device 3 is adapted to the position of the positioning device 2 and is detachably and fixedly connected to the bottom plate 1. After the frame parts to be welded are positioned according to the dimensions required by the design by the positioning device 2, the corresponding frame parts are pressed and fixed by the pressing device 3.
[0027] For the above-mentioned welding tooling for the upper fork and lower fork of the rear triangle of a bicycle frame, a plurality of groups of positioning threaded holes 1-1 are provided on the bottom plate 1, which are suitable for the detachable fixed connection of the positioning device 2 and the pressing device 3 at each working position.
[0028] For the above-mentioned welding tooling for the upper fork and lower fork of the rear triangle of a bicycle frame, the positioning device 2 includes a front positioning seat 2-1, a first positioning support 2-2, a second positioning support 2-3, a third positioning support 2-4, and a rear positioning seat 2-5 arranged in sequence along the A-A center line direction. The pressing device 3 includes a pressing head 3-2 adapted to the positioning device and a manipulation mechanism 3-1 for controlling the opening and closing of the pressing head 3-2.
[0029] For the above-mentioned welding tooling for the upper fork and lower fork of the rear triangle of a bicycle frame, the manipulation mechanism 3-1 includes a vertical quick clamp 3-11 and a push-pull quick clamp 3-12. The front positioning seat 2-1, the first positioning support 2-2, the second positioning support 2-3, and the third positioning support 2-4 are matched with the vertical quick clamp 3-11, and the rear positioning seat 2-5 is matched with the push-pull quick clamp 3-12.
[0030] Refer to Figures 1 to 8, for the above-mentioned welding tooling for the upper and lower forks of the rear triangle of the bicycle frame, the front positioning seat 2-1 is provided with a rear vertical surface 2-111 perpendicular to the upper surface of the bottom plate 1, the rear positioning seat 2-5 is provided with a front vertical surface 2-51 perpendicular to the upper surface of the bottom plate 1, and the left and right side vertical surfaces of the rear positioning seat 2-5 respectively extend vertically left and right to form lug positioning columns 2-52 matching with the lugs 101. The extending length of the lug positioning columns 2-52 is adjustable, and the extending end of the lug positioning column 2-52 is provided with an axial positioning shoulder section 2-53 adapted to the lug 101 and with a length not greater than the thickness of the lug 101. The first positioning support 2-2, the second positioning support 2-3, and the third positioning support 2-4 are all provided with a pair of positioning pieces 2-21. Each pair of the positioning pieces 2-21 is symmetrically arranged along the A-A center line. The positioning pieces 2-21 are provided with positioning grooves 2-211 matching with the corresponding bicycle frame parts. The positioning pieces 2-21 are provided with oblong holes 2-212. A plurality of threaded connection holes 2-22 matching with the oblong holes 2-212 are arranged on the front and rear surfaces of the first positioning support 2-2 and the third positioning support 2-4 and on the left and right surfaces of the second positioning support 2-3. The middle part of the front vertical surface of the second positioning support 2-3 vertically extends forward to form a positioning groove plate 2-31 adapted to the vertical edge 102-1 of the rear tile support 102.
[0031] See Figures 1 to 6 , before welding the lower fork of the rear triangle of the bicycle frame, rotate the lug positioning column 2-52, adjust the extending length of the extending end of the lug positioning column 2-52 to a proper position, respectively hook the left and right lugs 101 on the positioning shoulder section 2-53, adjust the front and rear positions of the first positioning support 2-2 and the third positioning support 2-4 and the left and right positions of the positioning pieces 2-21 thereon to proper positions. The oblong holes 2-212 on the positioning pieces 2-21 can also realize fine adjustment of the left and right positions of the positioning pieces 2-21. Place the two lower fork tubes 104 respectively in the positioning grooves 2-211 of the positioning pieces 2-21, adjust the front and rear positions of the front positioning seat 2-1 and the rear positioning seat 2-5 on the bottom plate 1, make the front end of the lower fork tube 104 abut against the rear vertical surface 2-111 on the front positioning seat 2-1, insert the tail of the lower fork tube 104 into the lug 101, adjust the front and rear position of the second positioning support 2-3 to a proper position, insert the vertical plate 102-1 of the rear tile support 102 into the positioning groove plate 2-31 of the second positioning support 2-3, and place the connecting plate of the rear tile support 102 on the two lower fork tubes 104. The above operations complete the positioning before welding the lower fork of the rear triangle of the bicycle frame.
[0032] See Figure 1 , Figure 2 , Figure 6 ,Figure 7 , before welding the upper fork of the rear triangle of the bicycle frame, adjust the front and rear positions of the first positioning support 2-2 and the third positioning support 2-4 and the left and right positions of the positioning piece 2-21 thereon to appropriate positions. The first long circular hole 2-212 on the positioning piece 2-21 can also realize fine adjustment of the left and right positions of the positioning piece 2-21. Place the two upper fork tubes 103 into the positioning grooves 2-211 of the positioning piece 2-21 respectively, adjust the front and rear positions of the front positioning seat 2-1 and the rear positioning seat 2-5 on the bottom plate 1, so that the front end of the upper fork tube 103 abuts against the rear vertical surface 2-111 on the front positioning seat 2-1, the tail of the upper fork tube 103 abuts against the front vertical surface 2-51 of the rear positioning seat 2-5, adjust the front and rear positions of the second positioning support 2-3 to appropriate positions, and place the short cross tube 105 into the positioning groove 2-2111 of the positioning piece 2-21 of the second positioning support 2-3. The above operations complete the positioning before welding the upper fork of the rear triangle of the bicycle frame.
[0033] See Figures 1 to 7, for the above-mentioned welding tooling for the upper and lower forks of the rear triangle of the bicycle frame, the basic shape of the front positioning seat 2-1 is L-shaped, including a vertical plate 2-11 and a connecting plate 2-12. Two long circular holes 2-121 are provided on the connecting plate 2-12 corresponding to the positioning threaded holes 1-1 at the front of the bottom plate 1. The middle part of the connecting plate 2-12 extends vertically upward to form a first mounting seat 2-13. A vertical quick clamp 3-111 is fixedly connected to the first mounting seat 2-13. The vertical quick clamp 3-111 controls the pressing head 3-2 to tightly fix the front section of the upper fork tube 104 or the lower fork tube 103 of the rear triangle of the bicycle frame at the first positioning support 2-2. A vertical quick clamp 3-112 is fixedly connected to the upper part of the second positioning support 2-3. The vertical quick clamp 3-112 controls the pressing head 3-2 to tightly fix the horizontal plate of the rear tile support 102 or the short cross tube 105. A third mounting seat detachably and fixedly connected to the bottom plate is provided at the front of the third positioning support 2-4. The third mounting seat is adapted to the positioning threaded holes 1-1 in the middle and rear parts of the bottom plate 1. A vertical quick clamp 3-113 is fixedly connected to the top of the third mounting seat. The vertical quick clamp 3-113 controls the pressing head 3-2 to tightly fix the rear section of the upper fork tube 103 or the lower fork tube 104 at the third positioning support 2-4. Rear mounting seats 3-3 are symmetrically arranged on the left and right sides of the rear positioning seat 2-5. The rear mounting seats 3-3 are detachably and fixedly connected to the bottom plate 1. The rear mounting seats 3-3 are adapted to two groups of the positioning threaded holes 1-1 at the rear of the bottom plate 1. The push-pull type quick clamps 3-12 are symmetrically fixedly connected to the two rear mounting seats 3-3. The push-pull type quick clamps 3-12 control the pressing head 3-2 to tightly fix the ear piece 101 sleeved on the positioning shoulder section 2-53. The above operations complete the tight fixing before welding the upper or lower fork of the rear triangle of the above-mentioned bicycle frame.
[0034] See Figure 8 , for the above-mentioned welding tooling for the upper and lower forks of the rear triangle of the bicycle frame, the positioning groove 2-211 of the positioning piece 2-21 is a U-shaped groove.
[0035] The embodiment of the utility model is a welding tool for the upper fork and the lower fork of the rear triangle of a bicycle frame. By adjusting the front and rear positions of the front positioning seat 2-1 and the rear positioning seat 2-5 on the bottom plate 1, the front and rear direction positioning requirements of the upper fork tube 103 and the lower fork tube 104 of the rear triangle of the bicycle frame with different length dimensions can be met. By adjusting the left and right positions of the positioning pieces 2-21 on the first positioning support 2-2 and the third positioning support 2-4, the left and right direction positioning requirements of the upper fork tube 103 and the lower fork tube 104 of the rear triangle of the bicycle frame with different widths can be met. By adjusting the front and rear positions of the second positioning support 2-3 on the bottom plate 1, the front and rear direction positioning requirements of the rear tile support 102 of the lower fork of the rear triangle of the bicycle frame and the short cross tube 105 of the upper fork of the rear triangle of the bicycle frame with different specifications and models can be met. When using the embodiment of the utility model to weld the upper fork and the lower fork of the rear triangle of the bicycle frame with different specifications and models, before welding, only the connection screws at the corresponding parts of the positioning device 2 and the pressing device 3 need to be loosened, and the positions of the positioning device 2 and the pressing device 3 on the bottom plate 1 can be adjusted, without having to replace the entire welding tool for the upper fork and the lower fork of the rear triangle of the bicycle frame. Since the types and quantities of the welding tools in bicycle production are reduced, the embodiment of the utility model reduces the auxiliary cost of bicycle production and the difficulty of production site management, and solves the problems of high auxiliary cost of bicycle production and great difficulty of production site management.
Claims
1. A welding tooling for the upper and lower forks of the rear triangle of a bicycle frame, characterized in that, It includes a bottom plate (1), a positioning device (2) and a pressing device (3). The bottom plate (1) is detachably and fixedly connected to a welding workbench. The positioning device (2) and the pressing device (3) are symmetrically arranged on the bottom plate (1) with respect to the A-A center line. The front, rear, left and right positions of the positioning device (2) relative to the bottom plate (1) are adjustable and it is detachably and fixedly connected to the bottom plate (1). The pressing device (3) is adapted to the position of the positioning device (2) and is detachably and fixedly connected to the bottom plate (1). After the frame parts to be welded are positioned according to the dimensions required by the design by the positioning device (2), the corresponding frame parts are pressed and fixed by the pressing device (3).
2. The welding tooling for the upper and lower forks of the rear triangle of a bicycle frame according to claim 1, characterized in that, Multiple groups of positioning threaded holes (1-1) are provided on the bottom plate (1) for the fixed connection of the positioning device (2) and the pressing device (3) at each working position.
3. The welding tooling for the upper and lower forks of the rear triangle of a bicycle frame according to claim 2, characterized in that, The positioning device (2) includes a front positioning seat (2-1), a first positioning support (2-2), a second positioning support (2-3), a third positioning support (2-4), and a rear positioning seat (2-5) arranged in sequence along the A-A center line direction. The pressing device (3) includes a pressing head (3-2) adapted to the positioning device and a control mechanism (3-1) for controlling the opening and closing of the pressing head (3-2).
4. The welding tooling for the upper and lower forks of the rear triangle of a bicycle frame according to claim 3, characterized in that, The control mechanism (3-1) includes a vertical quick clamp (3-11) and a push-pull quick clamp (3-12). The front positioning seat (2-1), the first positioning support (2-2), the second positioning support (2-3), and the third positioning support (2-4) are matched with the vertical quick clamp (3-11), and the rear positioning seat (2-5) is matched with the push-pull quick clamp (3-12).
5. The welding tooling for the upper and lower forks of the rear triangle of a bicycle frame according to claim 4, characterized in that, The front positioning seat (2-1) is provided with a rear vertical surface (2-111) perpendicular to the upper surface of the bottom plate (1). The rear positioning seat (2-5) is provided with a front vertical surface (2-511) perpendicular to the upper surface of the bottom plate (1). On the left and right side vertical surfaces of the rear positioning seat (2-5), earpiece positioning columns (2-52) matching the earpieces (101) extend vertically leftward and rightward respectively. The protruding length of the earpiece positioning columns (2-52) is adjustable. The protruding end of the earpiece positioning column (2-52) is provided with an axial positioning shoulder section (2-53) adapted to the earpiece (101) and having a length not greater than the thickness of the earpiece (101). The first positioning support (2-2), the second positioning support (2-3), and the third positioning support (2-4) are all provided with a pair of positioning plates (2-21). Each pair of the positioning plates (2-21) is symmetrically arranged along the A-A center line. The positioning plates (2-21) are provided with positioning grooves (2-211) matching the corresponding bicycle frame parts. The positioning plates (2-21) are provided with oblong holes one (2-212). On the front and rear surfaces of the first positioning support (2-2) and the third positioning support (2-4) and on the left and right surfaces of the second positioning support (2-3), a plurality of threaded connection holes (2-22) matching the oblong holes one (2-212) are provided. In the middle of the front vertical surface of the second positioning support (2-3), a positioning groove plate (2-31) extending vertically forward and adapted to the vertical edge (102-1) of the rear tile support (102) is provided.
6. The welding tooling for the upper and lower forks of the rear triangle of a bicycle frame according to claim 5, characterized in that, The basic shape of the front positioning seat (2-1) is L-shaped, including a vertical plate (2-11) and a connecting plate (2-12). Two oblong holes II (2-121) are provided on the connecting plate (2-12) corresponding to the positioning threaded holes (1-1) at the front part of the bottom plate (1). The middle part of the connecting plate (2-12) extends vertically upward to form a first mounting seat (2-13). A vertical quick clamp I (3-111) is fixedly connected to the first mounting seat (2-13). The pressing head of the vertical quick clamp I (3-111) presses and fixes the front section of the upper fork tube (103) or the lower fork tube (104) at the first positioning support (2-2). A vertical quick clamp II (3-112) is fixedly connected to the upper part of the second positioning support (2-3). The vertical quick clamp II (3-112) controls the pressing head (3-2) to press and fix the horizontal plate or the short cross tube (105) of the rear tile support (102). A third mounting seat detachably and fixedly connected to the bottom plate (1) is provided at the front part of the third positioning support (2-4). The third mounting seat is adapted to the positioning threaded holes (1-1) in the middle and rear parts of the bottom plate (1). A vertical quick clamp III (3-113) is fixedly connected to the top of the third mounting seat. The vertical quick clamp III (3-113) controls the pressing head (3-2) to press and fix the rear section of the upper fork tube (103) or the lower fork tube (104) at the third positioning support (2-4). Rear mounting seats (3-3) are symmetrically arranged on the left and right sides of the rear positioning seat (2-5). The rear mounting seats (3-3) are detachably and fixedly connected to the bottom plate (1). The rear mounting seats (3-3) are adapted to two groups of the positioning threaded holes (1-1) at the rear part of the bottom plate (1). The push-pull quick clamps (3-12) are symmetrically and fixedly connected to the two rear mounting seats (3-3). The push-pull quick clamps (3-12) control the pressing head (3-2) to press and fix the lug (101) sleeved on the positioning shoulder section (2-53).
7. The welding tooling for the upper and lower forks of the rear triangle of a bicycle frame according to claim 6, characterized in that, The positioning groove (2-211) of the positioning piece (2-21) is a U-shaped groove.