A welding positioning fixture for exhaust pipes

Abstract

This application discloses a welding positioning fixture for an exhaust pipe, relating to the field of welding fixtures. The welding positioning fixture includes a back plate base, a first positioning shaft, a second positioning shaft, a first clamping mechanism, and a second clamping mechanism. This application centers the exhaust pipe using the first positioning shaft, and the reference surface of the back plate base axially positions the exhaust pipe. Then, the second positioning shaft is brought closer to the first positioning shaft axially so that the positioning step surfaces of the first and second positioning shafts engage for positioning. The exhaust pipe and the second positioning shaft are then clamped by the first and second clamping mechanisms respectively, thereby completing the welding positioning of the exhaust pipe and the small pipe. This application forms positioning holes by connecting the arc grooves on the two positioning shafts, thereby limiting the circumferential angles of the small pipe and the exhaust pipe through the positioning holes. The two positioning holes correspond one-to-one with the two small pipes, and the two positioning holes are spaced at a predetermined angle in the circumferential direction to ensure the stability of the two small pipes during the welding process and the correct angles after welding.

Description

Technical Field

[0001] This application relates to the field of welding tooling, and more particularly to a welding positioning tooling for an exhaust pipe. Background Technology

[0002] During the manufacturing process of the exhaust pipe, two small pipes need to be welded onto the exhaust pipe, such as... Figure 1 As shown, the two small pipes need to be spaced at a certain angle β in the circumferential direction of the exhaust pipe, which is usually 90 degrees apart.

[0003] Currently, in the on-site manufacturing process, the welding and positioning of exhaust pipes are mainly completed by manual positioning and manual welding. The welding process depends on the experience and skill level of the welder. Due to the lack of dedicated positioning fixtures, the angle and position of the small pipe need to be repeatedly adjusted during welding, resulting in low production efficiency and the welding quality being greatly affected by human factors. Utility Model Content

[0004] This application provides a welding positioning fixture for exhaust pipes, used for rapid welding positioning of exhaust pipes and small pipes.

[0005] This application provides a welding positioning fixture for an exhaust pipe, including a back plate base, a first positioning shaft, a second positioning shaft, a first clamping mechanism, and a second clamping mechanism;

[0006] The backplate base is provided with a reference surface;

[0007] The first positioning axis is set on the reference plane, and the first positioning axis is provided with a first arc groove and a second arc groove, the first arc groove and the second arc groove being spaced apart by a predetermined angle in the circumferential direction of the first positioning axis; the first positioning axis is provided with a first positioning step surface;

[0008] The second positioning shaft is coaxially arranged with the first positioning shaft. The second positioning shaft is provided with a third arc groove and a fourth arc groove. The third arc groove connects with the first arc groove to form a first positioning hole, and the fourth arc groove cooperates with the second arc groove to form a second positioning hole. The two small tubes to be welded are respectively placed in the first positioning hole and the second positioning hole. The second positioning shaft is provided with a second positioning step surface. The first positioning step surface fits and connects with the second positioning step surface, thereby restricting the rotation of the second positioning shaft relative to the first positioning shaft.

[0009] The first pressing mechanism is connected to the back plate base and is used to press the exhaust pipe sleeved on the first positioning shaft onto the reference surface of the back plate base;

[0010] The second clamping mechanism, connected to the back plate base, is used to press the second positioning shaft onto the first positioning shaft.

[0011] Preferably, the back plate base is provided with a plurality of first mounting holes communicating with the reference surface, and the end face of the first positioning shaft is provided with a second mounting hole. The positioning pin passes through the first mounting hole and the second mounting hole to realize the connection of the first positioning shaft to the reference surface.

[0012] Preferably, a first identification part and a second identification part are respectively provided on the back plate base. The first identification part corresponds radially to the first tube to be welded, and the second identification part corresponds radially to the second tube to be welded.

[0013] Preferably, the first positioning shaft is provided with a shaft portion that extends along the axial direction of the first positioning shaft; the second positioning shaft is provided with a central hole, and the shaft portion is coaxially disposed in the central hole.

[0014] Preferably, the shaft portion is provided with an L-shaped sidewall, and a limiting block is provided on the inner circumference of the central hole. A limiting groove is formed between the limiting block and the L-shaped sidewall, and the bent head of the small tube is provided in the limiting groove.

[0015] Preferably, the L-shaped sidewall includes a first blocking wall and a second blocking wall, and a limiting groove is formed between the first blocking wall, the second blocking wall and the limiting block. The limiting groove is connected to the first positioning hole or the second positioning hole, and the bent head of the small tube is disposed in the limiting groove. The second blocking wall and the bent head abut against each other radially on the first positioning axis.

[0016] Preferably, it also includes a pressure ring, which is coaxially sleeved on the outer periphery of the second positioning shaft. The first end face of the pressure ring abuts against the end face of the exhaust pipe, and the pressing end of the first pressing mechanism abuts against the second end face of the pressure ring.

[0017] Preferably, the pressure ring component includes a pressure ring, a positioning ring, a contact ring, and an elastic element; the pressure ring is coaxially sleeved on the outer periphery of the second positioning shaft; the positioning ring is coaxially disposed on the pressure ring and coaxially inserted into the exhaust pipe; the contact ring is coaxially sleeved on the outer periphery of the positioning ring; the two ends of the elastic element are respectively connected to the contact ring and the pressure ring; the end face of the contact ring abuts against the end face of the exhaust pipe, and the pressing end of the first pressing mechanism abuts against the end face of the pressure ring.

[0018] Preferably, multiple elastic elements are arranged circumferentially between the contact ring and the pressure ring.

[0019] The welding positioning fixture of this application has at least the following beneficial effects:

[0020] The welding positioning fixture of this application is used for welding positioning of exhaust pipe and small pipe. Before welding, two small pipes are inserted into the welding holes on the inner circumferential wall of the exhaust pipe. Then, the exhaust pipe is sleeved on the outer circumferential surface of the first positioning shaft, and the end face of the exhaust pipe is attached to the reference surface of the back plate base. The exhaust pipe is centered by the first positioning shaft, and the reference surface is axially positioned by the exhaust pipe. Then, the exhaust pipe is rotated so that the two small pipes are rotated into the first arc groove and the second arc groove of the first positioning shaft respectively. Then, the second positioning shaft is moved axially closer to the first positioning shaft so that the positioning step surfaces of the first positioning shaft and the second positioning shaft are engaged and positioned. Then, the exhaust pipe and the second positioning shaft are pressed by the first clamping mechanism and the second clamping mechanism respectively, thereby completing the welding positioning of the exhaust pipe and the small pipe. Since both positioning shafts are provided with arc grooves, the arc grooves on the two positioning shafts are joined to form positioning holes, thereby limiting the circumferential angle of the small pipe and the exhaust pipe through the positioning holes. The two positioning holes correspond one-to-one with the two small pipes and the two positioning holes are circumferentially spaced at a predetermined angle to ensure the stability of the two small pipes during the welding process and the correct angle after welding. Attached Figure Description

[0021] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0022] Figure 1 Figure (A) is a front view of the exhaust pipe and the small pipe, and Figure (B) is an isometric view of the exhaust pipe and the small pipe.

[0023] Figure 2 This is a structural schematic diagram of the welding positioning fixture;

[0024] Figure 3 This is an exploded view of the first positioning shaft and the back plate base;

[0025] Figure 4 yes Figure 2 The diagram shows the structure behind the first clamping mechanism, the second clamping mechanism, and the pressure ring component;

[0026] Figure 5 This is an axial schematic diagram of the first positioning shaft and the back plate base in Embodiment 1;

[0027] Figure 6 yes Figure 5 A schematic diagram of the structure of the first positioning axis;

[0028] Figure 7 This is a schematic diagram of the structure of the second positioning axis in Embodiment 1;

[0029] Figure 8 This is a schematic diagram of the structure after the first and second positioning axes are positioned in Embodiment 1;

[0030] Figure 9 This is a schematic diagram of the first clamping mechanism;

[0031] Figure 10 This is a structural schematic diagram of the pressure ring component;

[0032] Figure 11 yes Figure 10 Cross-sectional view;

[0033] Figure 12 This is a schematic diagram of the structure of the first positioning axis in Embodiment 2;

[0034] Figure 13 This is a schematic diagram of the structure of the second positioning axis in Embodiment 2;

[0035] Figure 14 This is a schematic diagram of the structure of the first positioning axis in Embodiment 3;

[0036] Figure 15 This is a schematic diagram of the structure of the second positioning axis in Embodiment 3;

[0037] Figure 16 This is a plan view of the exhaust pipe, the first positioning shaft, and the second positioning shaft in Embodiment 3;

[0038] Figure 17 yes Figure 16 AA section view in the middle;

[0039] The annotations in the attached figures are explained as follows:

[0040] 100, Backplate base; 110, Reference surface; 120, Positioning pin; 130, First identification part; 140, Second identification part; 100a, First mounting hole;

[0041] 200, First positioning shaft; 200a, First arc groove; 200b, Second arc groove; 200c, Second mounting hole; 210, First positioning step surface; 220, Shaft portion; 221, L-shaped sidewall; 2211, First blocking wall; 2212, Second blocking wall;

[0042] 300, Second positioning shaft; 300a, Third arc groove; 300b, Fourth arc groove; 300c, Center hole; C1, First positioning hole; C2, Second positioning hole; 310, Second positioning step surface; 320, Limiting block; 321, Outer wall of the limiting block;

[0043] 400. First clamping mechanism;

[0044] 500. Second clamping mechanism;

[0045] 600. Pressure ring; 610. Pressure ring; 620. Positioning ring; 630. Contact ring; 640. Elastic element;

[0046] 700. Exhaust pipe;

[0047] 800, small tube; 810, bent head. Detailed Implementation

[0048] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0049] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0050] Example 1:

[0051] like Figure 2 As shown, this embodiment discloses a welding positioning fixture for an exhaust pipe, which is used to position the exhaust pipe 700 and two small pipes 800 during welding.

[0052] like Figure 2 As shown, the welding positioning fixture includes a back plate base 100, a first positioning shaft 200, a second positioning shaft 300, a first clamping mechanism 400, and a second clamping mechanism 500.

[0053] like Figure 3As shown, the backplate base 100 is fixedly disposed at a predetermined position to provide an installation base for various components. The backplate base 100 is provided with a reference surface 110, which is configured as a vertical surface. In this embodiment, the backplate base 100 is also provided with a first identification part 130 and a second identification part 140. The first identification part 130 is radially corresponding to one small tube 800 to be welded on the first positioning shaft 200, and the second identification part 140 is radially corresponding to another small tube 800 to be welded on the first positioning shaft 200. By providing two identification parts, it is convenient to guide the two small tubes 800 to be welded and the exhaust pipe 700 to rotate to a predetermined angle. In this embodiment, the first identification part 130 and the second identification part 140 can be block structures welded to the backplate base 100.

[0054] like Figure 3 As shown, the first positioning shaft 200 is cylindrical in shape, and a second mounting hole 200c is provided on the end face of the first positioning shaft 200. A plurality of first mounting holes 100a are provided on the back plate base 100, and the plurality of first mounting holes 100a are arrayed on the reference surface 110. When the positioning pin 120 passes through the first mounting hole 100a and is inserted into the second mounting hole 200c, the first positioning shaft 200 can be stably connected to the reference surface 110 of the back plate base 100.

[0055] In this embodiment, there are multiple first mounting holes 100a, which can be adapted to the installation of first positioning shafts 200 of different specifications to achieve quick tooling change. On the other hand, multiple positioning pins 120 can be inserted into the first mounting holes 100a and the second mounting holes 200c to achieve quick positioning, which is simple and fast.

[0056] like Figure 4 As shown, the outer diameter of the first positioning shaft 200 is equal to the inner diameter of the exhaust pipe 700, or the outer diameter of the first positioning shaft 200 is slightly smaller than the inner diameter of the exhaust pipe 700. Here, "slightly smaller" means, for example, the outer diameter of the first positioning shaft 200 is 0.95 to 0.98 times the inner diameter of the exhaust pipe 700, as long as the positioning accuracy requirements are met.

[0057] like Figure 5 and Figure 6 As shown, a first arc groove 200a and a second arc groove 200b are provided on the first positioning shaft 200. The first arc groove 200a and the second arc groove 200b are set at a predetermined angle interval in the circumferential direction of the first positioning shaft 200. The predetermined angle θ of the interval is preferably ninety degrees.

[0058] like Figure 7As shown, the second positioning shaft 300 is cylindrical in shape and is coaxially arranged with the first positioning shaft 200. The second positioning shaft 300 is located on the side of the first positioning shaft 200 facing away from the reference plane 110. The second positioning shaft 300 is provided with a third arc groove 300a and a fourth arc groove 300b spaced apart along the circumference. The interval angle between the third arc groove 300a and the fourth arc groove 300b is equal to the predetermined angle mentioned above.

[0059] like Figure 7 and Figure 8 As shown, after the first positioning shaft 200 and the second positioning shaft 300 are connected together, they cannot move relative to each other. In this embodiment, the preferred positioning method is as follows: the first positioning shaft 200 is provided with a first positioning step surface 210, and the second positioning shaft 300 is provided with a second positioning step surface 310 that cooperates with the first positioning step surface 210. The first positioning step surface 210 can fit against the second positioning step surface 310, and the two positioning step surfaces can be interlocked to restrict the rotation of the second positioning shaft 300 relative to the first positioning shaft 200 in the circumferential direction. Specifically, the first positioning shaft 200 is recessed along its axial direction to form a step groove, and the end face of the step groove in the axial direction is defined as the first positioning step surface 210. The second positioning shaft 300 extends along its axial direction and is provided with a step protrusion, which can be inserted into the step groove in the axial direction. The end face of the step protrusion in the axial direction is defined as the second positioning step surface 310. It should be explained that the axial direction described in this embodiment refers to the axial direction of the first positioning shaft 200. Since the first positioning shaft 200 and the second positioning shaft 300 are coaxially arranged, the axial direction is also the axial direction of the second positioning shaft 300. Similarly, the circumferential direction described in this embodiment refers to the circumferential direction of the first positioning shaft 200.

[0060] like Figure 8 As shown, in this embodiment, the first arc groove 200a and the third arc groove 300a can be joined to form an annular hole, called the first positioning hole C1. Similarly, the second arc groove 200b and the fourth arc groove 300b can be joined to form another annular hole, called the second positioning hole C2. The length direction of both the first positioning hole and the second positioning hole is radial (radial direction of the first positioning shaft). Of the two small tubes 800 to be welded, one small tube 800 passes through the first positioning hole, and the other small tube 800 passes through the second positioning hole. The circumferential angle of the two small tubes 800 is restricted by the two positioning holes respectively. Furthermore, the inner diameter of the two positioning holes is slightly larger than the outer diameter of the small tubes 800. For example, the inner diameter of the positioning hole is 1.1 to 1.3 times the outer diameter of the small tubes 800.

[0061] It should be noted that since the angle between the first arc groove 200a and the second arc groove 200b in the circumferential direction is constant, the circumferential angle between the first positioning hole and the second positioning hole is also constant, which can fix the two small tubes to be welded at an angle of 800 degrees.

[0062] like Figure 2 and Figure 9 As shown, the first pressing mechanism 400 is connected to the back plate base 100. The first pressing mechanism 400 can axially press the exhaust pipe 700, specifically pressing the exhaust pipe 700 onto the reference surface 110 of the back plate base 100. There can be multiple first pressing mechanisms 400. In this embodiment, two first pressing mechanisms 400 are shown, which are distributed vertically on both sides of the second pressing mechanism 500.

[0063] like Figure 2 As shown, the second pressing mechanism 500 is connected to the back plate base 100. The second pressing mechanism 500 can press the second positioning shaft 300 in the axial direction. Specifically, it presses the second positioning shaft 300 onto the first positioning shaft 200, so that the second positioning step surface 310 and the first positioning step surface 210 are in close contact.

[0064] like Figure 9 As shown, the first clamping mechanism 400 and the second clamping mechanism 500 have the same structure. Both the first clamping mechanism 400 and the second clamping mechanism 500 refer to quick clamps in the prior art, such as quick clamps of model GH-101-E. Of course, other models of quick clamps can also be used, and this embodiment does not limit this.

[0065] like Figure 2 As shown, the welding positioning fixture in this embodiment also includes a pressure ring 600, which is coaxially sleeved on the outer periphery of the second positioning ring 620. The first end face of the pressure ring 600 is axially fitted and abuts against the end face of the exhaust pipe 700. The pressing end of the first pressing mechanism 400 abuts against the second end face of the pressure ring 600. The first pressing mechanism 400 applies axial pressure to the exhaust pipe 700 through the pressure ring 600, so that the exhaust pipe 700 is pressed axially between the pressure ring 600 and the reference surface 110 of the back plate support, thereby achieving axial positioning of the exhaust pipe 700.

[0066] In this embodiment, the pressure ring 600 can evenly distribute the point pressure of the first pressing mechanism 400 to the end face of the exhaust pipe 700 through the pressure ring 600, transforming the point pressure into surface pressure and avoiding damage to some thin-walled exhaust pipes 700 caused by single-point pressure.

[0067] like Figure 2 and Figure 10As shown, the pressure ring 600 of this embodiment includes a pressure ring 610, a positioning ring 620, a contact ring 630, and an elastic member 640. The pressure ring 610 is coaxially sleeved on the outer periphery of the second positioning shaft 300. The positioning ring 620 is coaxially disposed on the end face of the pressure ring 610 facing the exhaust pipe 700, and is also coaxially sleeved on the outer periphery of the second positioning shaft 300. The positioning ring 620 can be coaxially inserted into the interior of the exhaust pipe 700. The outer diameter of the positioning ring 620 is equal to or slightly smaller than the inner diameter of the exhaust pipe 700. For example, the outer diameter of the positioning ring 620 is 0.95 to 1 times the inner diameter of the exhaust pipe 700. The contact ring 630 is coaxially sleeved on the outer periphery of the positioning ring 620, and the contact ring 630 can slide axially relative to the positioning ring 620. The two ends of the elastic member 640 are respectively connected to the contact ring 630 and the pressure ring 610, and the extension and retraction direction of the elastic member 640 is configured to be axial (the axial direction of the first positioning shaft).

[0068] like Figure 11 As shown, one end face of the contact ring 630 facing the exhaust pipe 700 is configured as the first end face of the pressure ring 600, which is axially fitted and abutting against the end face of the exhaust pipe 700. One end face of the pressure ring 610 away from the contact ring 630 is configured as the second end face of the pressure ring 600. The pressing end of the first pressing mechanism 400 can apply pressure to the second end face so that the exhaust pipe 700 is pressed against the reference surface 110 of the back plate support.

[0069] In this embodiment, the pressure ring 600 is provided with a positioning ring 620, which can ensure the coaxiality of the contact ring 630 and the exhaust pipe 700, thereby ensuring that the pressure of the first pressing mechanism 400 is evenly distributed on the exhaust pipe 700. The elastic element 640 is provided to achieve elastic pressing and avoid damage to the exhaust pipe 700. On the other hand, the elastic element 640 can be used to match the positioning of exhaust pipes 700 with different axial lengths. The elastic element 640 is preferably a spring, with its two ends connected to the pressure ring 610 and the contact ring 630, respectively. There are multiple elastic elements 640, which are evenly distributed along the circumference of the pressure ring 610.

[0070] The working principle of the welding positioning fixture in this embodiment is as follows:

[0071] The first step is to insert two small tubes 800 into the welded holes on the inner circumferential wall of the exhaust pipe 700, with the small tubes 800 passing through the inner circumferential wall of the exhaust pipe 700.

[0072] The second step is to install the first positioning shaft 200 on the reference surface 110 of the back plate base 100, and to stably connect the first positioning shaft 200 to the reference surface 110 by means of the positioning pin 120.

[0073] The third step is to put the exhaust pipe 700 with the inserted small tube 800 onto the outer periphery of the first positioning shaft 200, and then rotate the exhaust pipe 700 so that the two small tubes 800 correspond one-to-one with the first arc groove 200a and the second arc groove 200b on the first positioning shaft 200 respectively, and push the exhaust pipe 700 axially so that the small tubes 800 are pushed into the first arc groove 200a and the second arc groove 200b;

[0074] Fourth step, install the pressure ring 600 on the outer periphery of the second positioning shaft 300, then align the second positioning step surface 310 of the second positioning shaft 300 with the first positioning step surface 210 of the first positioning shaft 200 in the axial direction, and fit the second positioning step surface 310 against the first positioning step surface 210 in the axial direction, so that the second positioning shaft 300 and the first positioning shaft 200 cannot rotate relative to each other in the circumference. Then use the second pressing mechanism 500 to press the second positioning shaft 300 onto the first positioning shaft 200 in the axial direction.

[0075] The fifth step involves using the first clamping mechanism 400 and the pressure ring 600 to press the exhaust pipe 700 axially onto the reference surface 110, thereby completing the positioning of the exhaust pipe 700 and the small pipe 800. The exhaust pipe 700 is centered by the first positioning shaft 200 and its axial position is limited by the reference surface 110 and the pressure ring 600. The small pipe 800 has its circumferential angle limited by the positioning hole formed by the arc groove. Subsequently, the small pipe 800 and the exhaust pipe 700 can be welded together manually or by a welding robot.

[0076] Example 2:

[0077] The difference between this second embodiment and the first embodiment is that:

[0078] like Figure 12 and Figure 13 As shown, in this second embodiment, a shaft portion 220 is provided on the first positioning shaft 200. The shaft portion 220 is coaxially arranged with the first positioning shaft 200 and extends along the axial direction of the first positioning shaft 200. The shaft portion 220 is cylindrical. The second positioning shaft 300 is provided with a central hole 300c. The inner diameter of the central hole 300c is equal to the outer diameter of the shaft portion 220 or the inner diameter of the central hole 300c is slightly larger than the outer diameter of the shaft portion 220. For example, the inner diameter of the central hole 300c is 1.05 to 1.2 times the outer diameter of the shaft portion 220. The shaft portion 220 is coaxially arranged in the central hole 300c.

[0079] In this second embodiment, the shaft portion 220 is provided so that the second positioning shaft 300 can be coaxially aligned with the first positioning shaft 200. In this second embodiment, it is preferable that one end of the shaft portion 220 is configured as a tapered end, which facilitates the insertion of the shaft portion 220 into the central hole 300c.

[0080] Example 3:

[0081] The difference between this embodiment three and embodiment two is that:

[0082] like Figure 14 As shown, the shaft portion 220 in this embodiment has an irregularly shaped notch, which allows the outer peripheral sidewall of the shaft portion 220 to form an L-shaped sidewall 221. There are two L-shaped sidewalls 221 in total, which are used to limit the two small tubes 800 to be welded. It should be noted that under certain working conditions, the end of the small tube 800 needs to be provided with an elbow 810 (e.g. Figure 1 As shown in the figure, in this embodiment, the two L-shaped sidewalls 221 and the limiting block 320 inside the central hole 300c restrict the bends 810 of the two small tubes 800 so that the bends 810 cannot undergo radial displacement and circumferential rotation.

[0083] like Figure 15 As shown, a limiting block 320 is provided on the inner circumference of the central hole 300c. The limiting block 320 is correspondingly provided with the irregular notch. The limiting block 320 can be inserted into the irregular notch, so that a limiting groove is formed between the outer wall 321 of the limiting block and the L-shaped side wall 221. The limiting groove is radially connected with the first positioning hole or the second positioning hole formed by the two arc grooves. The bent head 810 of the small tube 800 is provided in the limiting groove. Since there are two L-shaped side walls 221 in this embodiment, two limiting grooves can be formed. One limiting groove is connected with the first positioning hole, and the other limiting groove is connected with the second positioning hole. The bent heads 810 of the two small tubes 800 are correspondingly provided in the limiting grooves.

[0084] like Figure 16 and Figure 17 As shown, the L-shaped sidewall 221 includes a first blocking wall 2211 and a second blocking wall 2212. Both the first blocking wall 2211 and the second blocking wall 2212 are arranged parallel to the axial direction of the first positioning shaft 200. One end of the first blocking wall 2211 is connected to the second blocking wall 2212 to form an L-shaped structure. The second blocking walls 2212 of the two L-shaped sidewalls 221 are connected together.

[0085] Among them, such as Figure 17 As shown, a limiting groove is formed between the first blocking wall 2211, the second blocking wall 2212 and the outer side wall 321 of the limiting block.

[0086] like Figure 17 As shown, the limiting principle is as follows: the first blocking wall 2211 and the outer wall 321 of the limiting block clamp the elbow 810, so that the elbow 810 cannot rotate. The second blocking wall 2212 abuts against the outer circumferential surface of the elbow 810 in the radial direction of the first positioning shaft 200, so that the elbow 810 cannot move in the radial direction.

[0087] In this embodiment, the limiting groove formed by the L-shaped sidewall 221 and the limiting block 320 limits the bending head 810 to ensure that the welding fixture can be carried out smoothly and accurately.

[0088] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A welding positioning tool for an exhaust pipe, characterized by, include: The back plate base (100) is provided with a reference surface (110); A first positioning shaft (200) is disposed on a reference plane (110). A first arc groove (200a) and a second arc groove (200b) are provided on the first positioning shaft (200). The first arc groove (200a) and the second arc groove (200b) are spaced apart by a predetermined angle in the circumferential direction of the first positioning shaft (200). A first positioning step surface (210) is provided on the first positioning shaft (200). The second positioning shaft (300) is coaxially arranged with the first positioning shaft (200). The second positioning shaft (300) is provided with a third arc groove (300a) and a fourth arc groove (300b). The third arc groove (300a) is connected with the first arc groove (200a) to form a first positioning hole (C1). The fourth arc groove (300b) is fitted with the second arc groove (200b) to form a second positioning hole (C2). The two small tubes (800) to be welded are respectively arranged in the first positioning hole (C1) and the second positioning hole (C2). The second positioning shaft (300) is provided with a second positioning step surface (310). The first positioning step surface (210) is fitted and connected with the second positioning step surface (310), thereby restricting the rotation of the second positioning shaft (300) relative to the first positioning shaft (200). The first pressing mechanism (400) is connected to the back plate base (100) and is used to press the exhaust pipe (700) sleeved on the first positioning shaft (200) onto the reference surface (110) of the back plate base (100); The second pressing mechanism (500) is connected to the back plate base (100) and is used to press the second positioning shaft (300) onto the first positioning shaft (200).

2. The welding positioning fixture of claim 1, wherein, The back plate base (100) is provided with a plurality of first mounting holes (100a) that are connected to the reference surface (110). The end face of the first positioning shaft (200) is provided with a second mounting hole (200c). The positioning pin (120) passes through the first mounting hole (100a) and the second mounting hole (200c) to realize the connection of the first positioning shaft (200) to the reference surface (110).

3. The welding positioning fixture of claim 1, wherein, The back plate base (100) is provided with a first identification part (130) and a second identification part (140). The first identification part (130) is radially corresponding to the first tube (800) to be welded; the second identification part (140) is radially corresponding to the second tube (800) to be welded.

4. The welding positioning fixture of claim 1, wherein, The first positioning shaft (200) is provided with a shaft portion (220), which extends along the axial direction of the first positioning shaft (200); the second positioning shaft (300) is provided with a central hole (300c), and the shaft portion (220) is coaxially disposed in the central hole (300c).

5. The welding positioning fixture according to claim 4, characterized in that, The shaft (220) is provided with an L-shaped sidewall (221), and a limiting block (320) is provided on the inner circumference of the central hole (300c). A limiting groove is formed between the limiting block (320) and the L-shaped sidewall (221), and the bent head (810) of the small tube (800) is provided in the limiting groove.

6. The welding positioning fixture according to claim 5, characterized in that, The L-shaped sidewall (221) includes a first blocking wall (2211) and a second blocking wall (2212). A limiting groove is formed between the first blocking wall (2211), the second blocking wall (2212) and the limiting block (320). The limiting groove is connected to the first positioning hole (C1) or the second positioning hole (C2). The bent head (810) of the small tube (800) is set in the limiting groove. The second blocking wall (2212) and the bent head (810) abut against each other radially on the first positioning shaft (200).

7. The welding positioning fixture according to any one of claims 1 to 6, characterized in that, It also includes a pressure ring (600), which is coaxially sleeved on the outer periphery of the second positioning shaft (300). The first end face of the pressure ring (600) abuts against the end face of the exhaust pipe (700), and the pressing end of the first pressing mechanism (400) abuts against the second end face of the pressure ring (600).

8. The welding positioning fixture according to claim 7, characterized in that, The pressure ring component (600) includes a pressure ring (610), a positioning ring (620), a contact ring (630), and an elastic element (640); the pressure ring (610) is coaxially sleeved on the outer periphery of the second positioning shaft (300); the positioning ring (620) is coaxially disposed on the pressure ring (610) and coaxially inserted into the exhaust pipe (700); the contact ring (630) is coaxially sleeved on the outer periphery of the positioning ring (620); the two ends of the elastic element (640) are respectively connected to the contact ring (630) and the pressure ring (610); the end face of the contact ring (630) is in contact with the end face of the exhaust pipe (700), and the pressing end of the first pressing mechanism (400) abuts against the end face of the pressure ring (610).

9. The welding positioning fixture according to claim 8, characterized in that, Multiple elastic elements (640) are arranged circumferentially between the contact ring (630) and the pressure ring (610).

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