Positioning tool for welding torsion tube and method of using same
By designing a positioning fixture for welding torsion tubes, the problems of insufficient clamping force and welding heat deformation were solved, achieving stable welding of torsion tubes and improving the performance of the equipment and production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHANGZHOU LONGGUANG MEDICAL TECH CO LTD
- Filing Date
- 2026-03-11
- Publication Date
- 2026-05-19
AI Technical Summary
Existing clamping fixtures cannot effectively clamp flexible torsion tubes, resulting in insufficient clamping force during welding. This makes it impossible to resist the shaking and displacement caused by welding heat deformation and the elastic rebound of the tube body, affecting welding accuracy and instrument performance.
A positioning fixture for welding torsion tubes was designed, including a lower base, an upper pressure plate, a limiting block, and an adapter structure. Through the cooperation of the limiting block and the adapter structure, the radial, circumferential, and axial positioning of the torsion tubes is achieved. The lifting and lowering of the upper pressure plate is precisely controlled by the drive component to ensure that the torsion tubes are subjected to uniform force during the welding process and to prevent shaking.
This technology enables stable clamping and welding of the torsion tube, improves welding accuracy and weld strength, reduces the risk of wire detachment, and meets the production requirements of interventional devices.
Smart Images
Figure CN121798926B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of pipe fittings technology, specifically relating to pipe fitting support, and particularly to positioning fixtures for welding torsion pipes and their usage methods. Background Technology
[0002] Medical flexible torque tubes are the core torque transmission components of minimally invasive interventional devices. In the manufacturing process of medical torque tubes, in order to further enhance their anti-torsion performance and eliminate the lag problem during flexible tube transmission, it is usually necessary to perform spiral winding reinforcement on the outer wall of the tube. After the winding is completed, the reinforcing winding must be firmly fixed to the end of the torque tube through end spot welding to prevent the winding from loosening or shifting during use, and to ensure stable torque transmission from the handle end to the distal end of the device. The positional accuracy and weld strength of the spot welding directly determine the operational reliability and clinical safety of the interventional device.
[0003] Existing clamping fixtures are mostly designed to fit smooth-walled tubing, with clamping surfaces that are either conventional planes or simple V-shaped structures. These fixtures cannot effectively conform to flexible torsion tubes with reinforced threads on the outer wall, only achieving localized point contact with the threaded protrusions. This results in uneven clamping force distribution and the core problem of insufficient clamping force. Furthermore, medical torsion tubes are made of soft, highly elastic material. The heat generated during spot welding causes localized thermal expansion and slight softening of the tube. Combined with the tube's own elastic rebound, existing fixtures cannot provide stable constraint and limiting, directly leading to weld point misalignment, winding positioning deviation, and severely substandard welding accuracy. This directly impacts the clinical safety and operational stability of interventional devices.
[0004] To avoid the defects of tooling clamping, some production processes use manual hand-held spot welding instead of tooling. However, manual hand-held spot welding is prone to hand tremors due to high temperature and electromagnetic interference, resulting in frequent problems such as incomplete welds and insufficient weld strength, and a high risk of wire detachment. At the same time, the weld position of hand-held positioning is inconsistent, resulting in extremely low yield rate and low manual efficiency during mass production, which cannot meet the needs of large-scale and standardized production of interventional devices.
[0005] Therefore, how to solve the problem of insufficient clamping force of existing clamping fixtures and their inability to resist the shaking and displacement caused by welding heat deformation and elastic rebound of the pipe body is a technical problem that urgently needs to be solved in this field.
[0006] It should be noted that the information disclosed in this background section is only for understanding the background technology of this application concept, and therefore, the above description is not considered to constitute information related to the technology. Summary of the Invention
[0007] This disclosure provides at least one positioning fixture for welding torsion tubes and its usage method.
[0008] In a first aspect, embodiments of this disclosure provide a positioning fixture for welding torsion tubes, comprising:
[0009] The lower base is fixed to the workbench and has an installation cavity at its upper end;
[0010] An upper pressure plate, which is vertically and flexibly disposed above the lower base, is used to limit the torsion tube;
[0011] The limiting block has a positioning groove on its upper surface that matches the torque tube, and can be lifted and installed in the mounting cavity.
[0012] At least one set of adapter structures is fixed to the upper surface of the lower base and is adapted to the threaded structure of the outer wall of the torsion tube;
[0013] In the initial state, the upper surface of the adapter structure is coplanar with the upper surface of the positioning groove;
[0014] After the torque tube is placed in the positioning groove, the upper pressure plate moves downward to limit the torque tube and pushes the limiting block downward so that the outer wall of the torque tube simultaneously abuts against the upper surface of the adapter structure and the positioning groove.
[0015] In one optional embodiment, the bottom wall of the upper pressure plate is provided with an arc-shaped groove that matches the diameter of the torsion tube, and convex strips are symmetrically provided on both sides of the arc-shaped groove;
[0016] When the upper pressure plate moves downward to limit the torque tube, the protrusion abuts against the limiting block to drive the limiting block to move downward.
[0017] In one optional embodiment, a lifting groove is formed on the upper surface of the positioning groove along the length direction, and the depth of the lifting groove is greater than the height of the adapter structure.
[0018] In one optional embodiment, the adapter structure is a positioning strip or a rib, and the adapter structures are evenly arranged along the axial direction of the torsion tube, with the spacing between two adjacent adapter structures matching the thread period of the outer wall of the torsion tube.
[0019] In one optional embodiment, the inner wall of the arc-shaped groove is further provided with a plurality of arc-shaped strips, which are evenly arranged along the length direction of the arc-shaped groove and are adapted to the thread structure of the outer wall of the torsion tube.
[0020] In one optional embodiment, a reset spring is provided inside the mounting cavity, the upper end of the reset spring abutting against the limiting block, and the reset spring is adapted to push the limiting block upward.
[0021] In one optional embodiment, the upper surface of the adapter structure is a helical surface that meshes with the thread on the outer wall of the torsion tube, and the height of the adapter structure is 0.3-3mm.
[0022] In one optional embodiment, the maximum lifting displacement of the limiting block is 0.5-5mm, and the two sides of the limiting block slide against the inner wall of the mounting cavity.
[0023] In one optional embodiment, the upper surface of the positioning groove is provided with an anti-slip layer or anti-slip texture, wherein the anti-slip layer is a medical-grade silicone layer or a rubber layer.
[0024] In one optional embodiment, a drive assembly is further included, which is connected to the upper pressure plate and is used to drive the upper pressure plate to rise and fall. The drive assembly is a cylinder, a hydraulic cylinder, or an electric push rod.
[0025] Secondly, this disclosure also provides a method for using a positioning fixture for welding torsion tubes, the method comprising:
[0026] S1, the upper pressure plate moves upward and disengages from the lower base so that the torsion tube can be placed in the positioning groove. At this time, the adapter structure and the surface of the limiting block remain coplanar.
[0027] S2, place the torsion tube with the outer contour structure into the positioning groove of the limiting block, so that the end of the torsion tube to be welded extends out of the tooling preset length, and the outer wall of the torsion tube is initially attached to the upper surface of the positioning groove.
[0028] S3, the upper pressure plate is driven to move downward by the drive component. The arc-shaped groove on the bottom wall of the upper pressure plate abuts against the upper surface of the torsion tube to form a radial limit. At the same time, the protrusions on both sides of the upper pressure plate abut against the upper surface of the limit block, pushing the limit block to move downward along the mounting cavity of the lower base.
[0029] S4, when the limiting block is displaced to the preset position, the outer wall of the torsion tube is completely and tightly abutted against the upper surface of the adapter structure and the upper surface of the positioning groove, thereby achieving radial, circumferential and axial limiting of the torsion tube;
[0030] S5, spot welding is performed on the end of the torsion tube. During the spot welding process, the swaying caused by thermal expansion and elastic rebound of the torsion tube is suppressed by the coordinated constraint of the adapter structure and the positioning groove.
[0031] S6. After spot welding is completed, the upper pressure plate is driven upward to reset by the drive component. The limit block is reset upward to the initial position under the action of the elastic reset component, and the welded torsion tube is taken out.
[0032] The beneficial effects of this invention are that it provides a positioning fixture for welding torsion tubes and its usage method. By setting a liftable limiting block on the lower base and an adapter structure (positioning strip or rib) fixed on the lower base that precisely matches the threaded structure of the outer wall of the torsion tube, the positioning groove of the limiting block forms a clamping mode of upper and lower wrapping and threaded engagement. This completely changes the defect of "local point contact" of traditional fixtures, greatly increases the clamping contact area, and makes the clamping force evenly distributed along the circumference and axial direction of the tube body. It effectively solves the problem of insufficient clamping force caused by the soft material and threaded protrusion of flexible torsion tubes, and achieves reliable positioning of the tube body.
[0033] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.
[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description
[0035] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0036] Figure 1 A perspective view of the positioning fixture for welding torsion tubes provided in the embodiments of this disclosure;
[0037] Figure 2 A perspective view of the lower base and upper pressure plate provided in an embodiment of this disclosure;
[0038] Figure 3 A sectional front view of the lower base provided in an embodiment of this disclosure;
[0039] Figure 4 A schematic diagram showing the state of the adapter structure protruding from the upper surface of the positioning groove provided in the embodiments of this disclosure;
[0040] Figure 5 A perspective view of the positioning strip protruding from the upper surface of the limiting block, provided in an embodiment of this disclosure.
[0041] In the picture:
[0042] 1. Workbench; 10. Drive components;
[0043] 2. Lower base; 20. Mounting cavity; 21. Return spring;
[0044] 3. Upper pressure plate; 30. Arc-shaped groove; 31. Raised strip;
[0045] 4. Limiting block; 40. Positioning groove; 41. Lifting groove;
[0046] 5. Adaptive structure; 50. Positioning strip. Detailed Implementation
[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0048] In this document, when it is mentioned that a first component is located on a second component, this can mean that the first component can be directly formed on the second component, or that a third component can be inserted between the first and second components. Furthermore, in the accompanying drawings, the thickness of the components may be exaggerated or reduced for the purpose of effectively describing the technical content.
[0049] In this document, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as “at least one of…” modify an entire column of elements when following a column of elements. For example, the expression “at least one of a, b, and c” should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.
[0050] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless otherwise expressly stated herein. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.
[0051] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.
[0052] Research has revealed that existing clamping fixtures are mostly designed for smooth-walled tubing, with clamping surfaces that are either conventional planes or simple V-shaped structures. These fixtures cannot effectively conform to flexible torsion tubes with reinforced threads on the outer wall, only achieving localized point contact with the threaded protrusions. This results in uneven clamping force distribution and a core problem of insufficient clamping force. Furthermore, medical torsion tubes are made of soft, highly elastic material. The heat generated during spot welding causes localized thermal expansion and slight softening of the tube. Combined with the tube's own elastic rebound, existing fixtures cannot provide stable constraint and limiting, directly leading to weld point misalignment, winding positioning deviation, and severely substandard welding accuracy, which affects the performance of subsequent instruments.
[0053] To avoid the defects of tooling clamping, some production processes use manual hand-held spot welding instead of tooling. However, manual hand-held spot welding is prone to hand tremors due to high temperature and electromagnetic interference, resulting in frequent problems such as incomplete welds and insufficient weld strength, and a high risk of wire detachment. At the same time, the weld position of hand-held positioning is inconsistent, resulting in extremely low yield rate and low manual efficiency during mass production, which cannot meet the needs of large-scale and standardized production of interventional devices.
[0054] Therefore, how to solve the problem of insufficient clamping force of existing clamping fixtures and their inability to resist the shaking and displacement caused by welding heat deformation and elastic rebound of the pipe body is a technical problem that urgently needs to be solved in this field.
[0055] The defects in the above solutions and the reasons for their occurrence are the results of the inventors' practice and careful research. Therefore, the discovery process of the above problems and the solutions proposed in this disclosure should be considered as the inventors' contributions to this disclosure.
[0056] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0057] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0058] like Figure 1 As shown, at least one embodiment provides a positioning fixture for welding torque tubes, including: a lower base 2, which is fixed on a workbench 1 and has an installation cavity 20 at its upper end; the lower base 2 is made of medical-grade 304 stainless steel and has an overall cuboid structure; the lower base 2 is fixed to the workbench 1 by a bolt assembly (detachable connection structure) to ensure that the fixture is firmly fixed to the bearing surface and there is no vibration transmission; a return spring 21 is provided on the bottom wall of the installation cavity 20, and the upper end of the return spring 21 abuts against the bottom of the limiting block 4 to provide a stable return spring force. In the initial state, the return spring 21 pushes the limiting block 4 upward to make the upper surface of the limiting block 4 and the upper surface of the adapter structure 5 coplanar, so that the torque tube can be placed in the positioning groove 40.
[0059] like Figure 2 The upper pressure plate 3 is vertically mounted above the lower base 2 to limit the torque tube. The upper pressure plate 3 is made of medical-grade 304 stainless steel. Preferably, the upper pressure plate 3 is vertically mounted relative to the lower base 2 via guide columns (not shown in the figure) on both sides to ensure verticality without deviation during the lifting process. An arc-shaped groove 30 is formed in the middle of the bottom wall of the upper pressure plate 3. The radius of the arc-shaped groove 30 matches the diameter of the torque tube. Several arc-shaped strips are also provided on the inner wall of the arc-shaped groove 30. The arc-shaped strips are evenly arranged along the length direction of the arc-shaped groove 30 (the axial direction of the torque tube) and are adapted to the thread structure of the outer wall of the torque tube to further enhance the stability of radial clamping. The arc-shaped groove 30 is symmetrically provided with protrusions 31 on both sides. The protrusions 31 extend along the axial direction of the torque tube. The lower surface of the protrusions 31 is parallel to the upper surface of the limiting block 4 to ensure that the limiting block 4 is driven to descend evenly when pressed down.
[0060] like Figure 2 and Figure 3 As shown, the limiting block 4 has a positioning groove 40 on its upper surface that matches the torque tube, and can be lifted and installed in the mounting cavity 20. The limiting block 4 is made of high-strength engineering plastic (PEEK), and its two sides are clearance-fitted with the inner wall of the mounting cavity 20, with a clearance of 0.05mm to ensure smooth lifting without jamming. The maximum lifting displacement of the limiting block 4 is 0.5-5mm, preferably 2mm. The two sides of the limiting block 4 are in sliding fit with the inner wall of the mounting cavity 20. In the initial state, the upper surface of the positioning groove 40 in the limiting block 4 is coplanar with the upper surface of the positioning strip 50 of the adapter structure 5 (e.g., ...). Figure 3 When the limit block 4 is pushed downward (e.g.) Figure 5The positioning strip 50 of the adapter structure 5 protrudes from the upper surface of the positioning groove 40 opened in the limiting block 4 and abuts against the outer wall of the torque tube. That is, the limiting block 4 is pushed downward by the thread peak of the torque tube, while the positioning strip 50 contacts the thread valley of the torque tube. A semi-circular positioning groove 40 is opened along the length direction on the upper surface of the limiting block 4 (the radius of the positioning groove 40 is adapted to the diameter of the torque tube). A 0.5mm thick medical silicone anti-slip layer (with fine anti-slip texture on the surface of the anti-slip layer) is attached inside the groove to enhance friction and prevent damage to the tube body. A lifting groove 41 is opened along the length direction on the upper surface of the positioning groove 40. Here, the length direction refers to the radial direction when the torque tube is placed horizontally. The depth of the lifting groove 41 is greater than the height of the adapter structure 5 to avoid the adapter structure 5 and ensure that there is no interference when the limiting block 4 descends.
[0061] Continue to refer to the appendix Figure 2 At least one set of adapter structures 5 are fixed to the upper surface of the lower base 2 and are adapted to the threaded structure of the outer wall of the torsion tube. The adapter structure 5 can be a positioning strip 50 or a rib. In this embodiment, the positioning strip 50 is preferred. It is adapted to the thread of the outer wall of the torsion tube and is made of medical grade stainless steel. It is evenly distributed along the length direction (axial direction of the torsion tube) of the upper surface of the lower base 2. The spacing between adjacent positioning strips 50 is consistent with the thread period of the outer wall of the torsion tube. The cross-section of the positioning strip 50 is trapezoidal. The upper surface is machined into a helical surface that meshes with the thread of the outer wall of the torsion tube. The helical angle is consistent with the thread angle of the torsion tube. The height of the positioning strip 50 is 1.5 mm, which is in the preferred range of 0.3-3 mm. The width is adapted to the lifting groove 41. In the initial state, the upper surface of the adapter structure 5 is coplanar with the upper surface of the positioning groove 40. After the torque tube is placed in the positioning groove 40, the upper pressure plate 3 moves downward to limit the torque tube and pushes the limiting block 4 downward so that the outer wall of the torque tube simultaneously abuts against the upper surfaces of the adapter structure 5 and the positioning groove 40.
[0062] like Figure 1 The workbench 1 also includes a drive assembly 10, which is connected to the upper pressure plate 3 and is used to drive the upper pressure plate 3 to rise and fall. The drive assembly 10 is a cylinder, a hydraulic cylinder, or an electric push rod. Preferably, a small cylinder is used as the drive assembly 10, and the cylinder piston rod is connected to the top center of the upper pressure plate 3 through a floating joint. The cylinder is fixed below the workbench 1 by a bracket and is equipped with an electromagnetic reversing valve and a pressure regulating valve, which can accurately control the rising and falling speed and clamping force of the upper pressure plate 3, and adapt to the clamping requirements of the flexible torsion tube.
[0063] At least one embodiment also provides a method of using a positioning fixture for welding torsion tubes, the method comprising:
[0064] S1, the upper pressure plate 3 moves upward and disengages from the lower base 2 so that the torsion tube can be placed in the positioning groove 40. At this time, the adapter structure 5 and the surface of the limiting block 4 remain coplanar.
[0065] S2, place the to-be-welded torsion tube with an outer contour structure into the positioning groove 40 of the limiting block 4, so that the end of the to-be-welded torsion tube extends out of the tooling preset length, and the outer wall of the torsion tube is initially attached to the upper surface of the positioning groove 40.
[0066] S3, the upper pressure plate 3 is driven to move downward by the drive assembly 10. The arc-shaped groove 30 on the bottom wall of the upper pressure plate 3 abuts against the upper surface of the torsion tube to form a radial limit. At the same time, the protrusions 31 on both sides of the upper pressure plate 3 abut against the upper surface of the limit block 4, pushing the limit block 4 to move downward along the mounting cavity 20 of the lower base 2.
[0067] S4, when the limiting block 4 is displaced to the preset position, the outer wall of the torsion tube is completely and tightly abutted against the upper surface of the adapter structure 5 and the upper surface of the positioning groove 40, thereby achieving radial, circumferential and axial limiting of the torsion tube.
[0068] S5, perform spot welding on the end of the torsion tube. During the spot welding process, the swaying caused by thermal expansion and elastic rebound of the torsion tube is suppressed by the coordinated constraint of the adapter structure 5 and the positioning groove 40.
[0069] S6. After spot welding is completed, the upper pressure plate 3 is driven upward to reset by the drive component 10, and the limit block 4 is reset upward to the initial position under the action of the elastic reset component. The welded torsion tube is then removed.
[0070] The working principle of the positioning fixture for welding torsion tubes is as follows:
[0071] Driven by the drive assembly 10, the upper pressure plate 3 is moved upward to the maximum stroke and disengaged from the lower base 2. At this time, the limit block 4 is in the initial position under the action of the return spring 21. The upper surface of the adapter structure 5 is coplanar with the upper surface of the positioning groove 40, which facilitates the placement of the torque tube.
[0072] like Figure 4 The medical flexible torsion tube (with threaded structure) to be welded is placed in the positioning groove 40, so that the end of the torsion tube to be welded extends 5mm beyond the front end of the tooling (set according to the size of the welding joint). The outer wall of the torsion tube is initially attached to the silicone anti-slip layer in the positioning groove 40, and the threaded structure is initially engaged with the adapter structure 5 in the positioning groove 40. The drive assembly 10 drives the upper pressure plate 3 to move downward. The arc-shaped groove 30 on the bottom wall of the upper pressure plate 3 is tightly abutted against the upper surface of the torsion tube, forming a radial limit. At the same time, the two side protrusions 31 abut against the upper surface of the limit block 4, overcoming the elastic force of the return spring 21 and pushing the limit block 4 to move downward along the mounting cavity 20. During the displacement, the two sides of the limit block 4 slide against the inner wall of the mounting cavity 20 without deviation.
[0073] When the limiting block 4 moves downward to the preset position, the upper pressure plate 3 stops descending; at this time, the threaded structure of the outer wall of the torsion tube is fully engaged with the spiral surface of the adapter structure 5, and at the same time, it is in close contact with the arc strip on the upper surface of the positioning groove 40 and the inner wall of the arc groove 30, so as to achieve full radial, circumferential and axial limiting, and the torsion tube has no loosening or movement space.
[0074] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.
[0075] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence unless expressly indicated herein. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed above may be referred to as a second element, component, region, layer, or segment.
[0076] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.
Claims
1. A positioning fixture for welding torsion tubes, characterized in that, include: The lower base (2) is fixed on the workbench (1) and has an installation cavity (20) at its upper end. The upper pressure plate (3) is vertically mounted above the lower base (2) and is used to limit the torque tube; The limiting block (4) has a positioning groove (40) on its upper surface that matches the torque tube, and can be lifted and installed in the mounting cavity (20); At least one set of adapter structures (5) are fixed to the upper surface of the lower base (2) and are adapted to the threaded structure of the outer wall of the torsion tube; In the initial state, the upper surface of the adapter structure (5) is coplanar with the upper surface of the positioning groove (40); After the torsion tube is placed in the positioning groove (40), the upper pressure plate (3) moves downward to limit the torsion tube and pushes the limiting block (4) downward so that the outer wall of the torsion tube simultaneously abuts against the upper surface of the adapter structure (5) and the positioning groove (40). The bottom wall of the upper pressure plate (3) is provided with an arc-shaped groove (30) that matches the diameter of the torsion tube, and the two sides of the arc-shaped groove (30) are symmetrically provided with protrusions (31). When the upper pressure plate (3) moves downward to limit the torque tube, the protrusion (31) abuts against the limiting block (4) to drive the limiting block (4) to move downward. The adapter structure (5) is a positioning strip (50) or a rib, and the adapter structure (5) is evenly arranged along the axial direction of the torsion tube. The spacing between two adjacent adapter structures (5) is adapted to the thread period of the outer wall of the torsion tube. A reset spring (21) is provided in the mounting cavity (20). The upper end of the reset spring (21) abuts against the limiting block (4). The reset spring (21) is adapted to push the limiting block (4) upward.
2. The positioning fixture for welding torsion tubes as described in claim 1, characterized in that, The upper surface of the positioning groove (40) is provided with a lifting groove (41) along the length direction, and the depth of the lifting groove (41) is greater than the height of the adapter structure (5).
3. The positioning fixture for welding torsion tubes as described in claim 1, characterized in that, The inner wall of the arc-shaped groove (30) is also provided with several arc-shaped strips, which are evenly arranged along the length of the arc-shaped groove (30) and are adapted to the thread structure of the outer wall of the torsion tube.
4. The positioning fixture for welding torsion tubes as described in claim 1, characterized in that, The upper surface of the adapter structure (5) is a helical surface that meshes with the thread on the outer wall of the torsion tube, and the height of the adapter structure (5) is 0.3-3mm.
5. The positioning fixture for welding torsion tubes as described in claim 4, characterized in that, The maximum lifting displacement of the limiting block (4) is 0.5-5mm, and the two sides of the limiting block (4) slide against the inner wall of the mounting cavity (20).
6. The positioning fixture for welding torsion tubes as described in claim 1, characterized in that, The upper surface of the positioning groove (40) is provided with an anti-slip layer or anti-slip texture, wherein the anti-slip layer is a medical-grade silicone layer or a rubber layer.
7. The positioning fixture for welding torsion tubes as described in claim 1, characterized in that, It also includes a drive assembly (10), which is connected to the upper pressure plate (3) and is used to drive the upper pressure plate (3) to rise and fall. The drive assembly (10) is a cylinder, a hydraulic cylinder or an electric push rod.
8. A method of using a positioning fixture for welding torsion tubes, characterized in that, The method of using the positioning fixture for welding torque tubes as described in any one of claims 1-7 includes: S1, the upper pressure plate (3) moves upward and disengages from the lower base (2) so that the torsion tube can be placed in the positioning groove (40). At this time, the surface of the adapter structure (5) and the limiting block (4) remains coplanar. S2, place the to-be-welded torsion tube with an outer contour structure into the positioning groove (40) of the limiting block (4), so that the end of the to-be-welded torsion tube extends out of the tooling preset length, and the outer wall of the torsion tube is initially attached to the upper surface of the positioning groove (40). S3, the upper pressure plate (3) is driven to move downward by the drive assembly (10). The arc groove (30) on the bottom wall of the upper pressure plate (3) abuts against the upper surface of the torsion tube to form a radial limit. At the same time, the protrusions (31) on both sides of the upper pressure plate (3) abut against the upper surface of the limit block (4) and push the limit block (4) to move downward along the mounting cavity (20) of the lower base (2). S4, when the limiting block (4) is displaced to the preset position, the outer wall of the torsion tube is completely in close contact with the upper surface of the adapter structure (5) and the upper surface of the positioning groove (40), thereby realizing the radial, circumferential and axial limiting of the torsion tube; S5, spot welding is performed on the end of the torsion tube. During the spot welding process, the swaying caused by thermal expansion and elastic rebound of the torsion tube is suppressed by the coordinated constraint of the adapter structure (5) and the positioning groove (40). S6. After spot welding is completed, the upper pressure plate (3) is driven upward by the drive assembly (10), and the limit block (4) is reset upward to the initial position under the action of the elastic reset component. The welded torsion tube is then removed.