Welding tool and welding method for piston rod of automobile shock absorber

Abstract

The invention belongs to the technical field of automobile shock absorbers, and particularly relates to an automobile shock absorber piston rod welding tool and a welding method. The welding tool comprises an electrode made of a copper alloy material, and the electrode comprises an electrode body and a protruding part; an upper column cavity and a lower column cavity which are adjacently arranged up and down are formed in the electrode body, the upper column cavity, the lower column cavity and the electrode body are coaxially arranged, and a mounting through hole is formed in the protruding part; a steel sleeve is fixedly arranged in the upper column cavity, and an inner cavity of the steel sleeve and the lower column cavity are coaxially and adjacently arranged to form a threaded rod positioning cavity; a threaded rod positioning piece is further included. The rigidity and strength of the side wall of the upper portion of the threaded rod positioning cavity are improved by arranging the steel sleeve forming the threaded rod positioning cavity with the lower column cavity, the service life of the welding tool is prolonged, and the production cost is saved; the radial positioning precision of the threaded rod is improved, and the welding coaxiality of the threaded rod and the piston rod body is guaranteed. According to the welding method, the threaded rod positioning piece is arranged to be the welding tool of the magnetic attraction block, rapid clamping and disassembling of the threaded rod are achieved, and the working efficiency of welding operation is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile shock absorbers, and in particular relates to a welding tool and a welding method for a piston rod of an automobile shock absorber. Background Art

[0002] Automobile shock absorbers are important components of automobile suspensions. Their main function is to cushion vibrations during the driving of the automobile, which has an important impact on the stability and safety of the driving of the automobile. Automobile shock absorbers include a cylinder, a piston and a piston rod. The lower end of the piston rod is connected to the piston, and the upper end of the piston rod is supported and connected to the automobile suspension. During the driving of the vehicle, the automobile suspension drives the piston rod and the piston to reciprocate axially. Therefore, as an important supporting component of the shock absorber, the piston rod has high requirements for strength and processing accuracy. Figure 1 As shown, the piston rod includes a coaxially welded piston rod body 91 and a threaded rod, and the coaxiality between the two is required to be less than φ1mm. Among them, the threaded rod includes a coaxially arranged threaded section 92 and a welding section 93, and the thread on the threaded section 92 can be a full thread or a non-full thread; the outer diameter of the welding section 93 is larger than the outer diameter of the threaded section 92, and there is a shoulder between the two, which is convenient for clamping and positioning during the welding operation of the threaded rod. During welding, the piston rod body 91 and the welding section 93 are coaxially welded.

[0003] Friction welding is generally used between the piston rod body 91 and the threaded rod. After welding, flash will be generated at the weld, which must be machined again. The process is cumbersome and the cost is high. In order to improve welding quality and save costs, the Chinese invention patent application document with publication number CN117884748A records a resistance welding fixture and method between shock absorber rods. The welding fixture includes a threaded rod electrode and an electrode seat. The threaded rod electrode is fixed to the electrode seat by bolts, and the bottom of the electrode seat and the connection between the threaded rod electrode are tightened horizontally inward; a groove for accommodating the threaded rod is provided at the center of the threaded rod electrode, and a thimble is also provided inside the threaded rod electrode. A spring is provided inside the thimble, and a sphere is provided at the top of the spring to abut against the threaded rod. When clamping the threaded rod, first fix the piston rod, then insert the threaded rod into the inner hole of the threaded rod electrode and push the threaded rod axially until the shoulder of the threaded rod fits with the lower end face of the threaded rod electrode, ensuring that the thimble presses against the threaded rod to position it axially, and the piston rod is coaxial with the threaded rod. The following shortcomings exist in welding operations using this device:

[0004] 1. Because the inner hole of the threaded rod electrode is small, it is more difficult to align and insert the threaded rod into the inner hole of the threaded rod electrode;

[0005] 2. The ejector pin is set inside the threaded rod electrode and cannot be seen, which makes it impossible to confirm whether the threaded rod is tightened by the ejector pin. Therefore, the threaded rod needs to be pushed axially to the limit position. The clamping operator has to move a lot, which may cause the threaded rod to not be clamped in place or fall off.

[0006] 3. During the process of installing and removing the threaded rod, the tip of the ejector pin and the threaded section 92 scrape against each other, which not only easily damages the threads on the threaded rod, but also accelerates the wear of the ejector pin;

[0007] 4. The spring in the ejector pin frequently expands and contracts, which is prone to fatigue failure, causing the ejector pin to be unable to hold the threaded rod tightly in place, which in turn causes damage to the welding fixture and requires timely replacement;

[0008] 5. The electrode holder and threaded rod electrode in the resistance welding process are made of copper alloy, which has low hardness and rigidity. During the pressurized welding process, the threaded rod will be squeezed by the pressure and the inner hole of the threaded rod electrode will be gradually deformed. If the deformation of the inner hole of the threaded rod electrode is too large, it will cause the threaded rod to deviate from the preset axis, affecting the positioning accuracy of the threaded rod, resulting in unqualified welding coaxiality between the threaded rod and the piston rod body 91. In order to ensure the welding quality, the threaded rod electrode needs to be frequently observed and replaced, which results in a long equipment downtime, reduces production efficiency, wastes manpower, and increases production costs. Summary of the invention

[0009] The technical problems to be solved by the present invention are: to provide a welding tool for a piston rod of an automobile shock absorber, to improve the welding coaxiality between a threaded rod and a piston rod body, to extend the service life of the welding tool, and to save production costs; to provide a welding method for a piston rod of a shock absorber, to quickly and labor-savingly complete the assembly and disassembly of the threaded rod, to improve the work efficiency of the welding operation, and to save manpower.

[0010] The technical solution adopted by the present invention to solve the technical problem is: a welding tool for a piston rod of an automobile shock absorber, comprising an electrode made of a copper alloy, wherein the electrode comprises an electrode body of a cylindrical structure and a protrusion arranged on the lower outer side wall of the electrode body;

[0011] The electrode body is provided with an upper column cavity with an opening facing upward and a lower column cavity with an opening facing downward, the upper column cavity and the lower column cavity are arranged adjacent to each other up and down and have a first step surface at the adjacent position, the outer diameter of the upper column cavity is greater than the outer diameter of the lower column cavity; the upper column cavity, the lower column cavity and the electrode body are arranged coaxially, and the protruding portion is provided with an axially penetrating mounting through hole;

[0012] A steel sleeve is fixedly arranged in the upper column cavity, and the inner cavity of the steel sleeve is coaxially arranged adjacent to the lower column cavity to form a threaded rod positioning cavity; and a threaded rod positioning member for axially positioning the threaded rod is also included.

[0013] Furthermore, the protrusion is a limiting ring plate coaxially arranged with the electrode body.

[0014] Furthermore, the limiting ring plate is provided with at least two mounting through holes, and the at least two mounting through holes are evenly distributed along the circumference of the limiting ring plate.

[0015] Furthermore, the cross-sectional outer contour of the upper column cavity is adapted to the shape and size of the cross-sectional outer contour of the steel sleeve, and the outer side surface of the steel sleeve is in contact with the side wall of the upper column cavity;

[0016] A plurality of radial through holes are arranged on the side wall of the electrode body, and the plurality of radial through holes are evenly distributed along the circumference of the electrode body; a threaded positioning hole coaxial with the radial through hole is arranged on the outer wall of the steel sleeve, and a fastening screw is arranged in the radial through hole, and the fastening screw is threadedly connected with the threaded positioning hole on the steel sleeve.

[0017] Furthermore, the lower column cavity is a stepped hole, and the large hole of the stepped hole is located below the small hole of the stepped hole;

[0018] The inner cavity of the steel sleeve is coaxially arranged adjacent to the small hole of the step hole to form a threaded rod positioning cavity; the large hole of the step hole is used to accommodate the welding section of the threaded rod and its depth is less than the axial length of the welding section.

[0019] Furthermore, the steel sleeve protrudes from the upper end surface of the electrode body.

[0020] Furthermore, the threaded rod positioning piece is a magnetic block arranged on the upper part of the steel sleeve.

[0021] Furthermore, an isolation portion is provided in the cavity of the steel sleeve, an upper cavity is above the isolation portion, and a lower cavity is below the isolation portion, the magnetic block is located in the upper cavity and adsorbed on the isolation portion; the lower cavity and the lower column cavity are arranged adjacent to each other up and down to form the threaded rod positioning cavity.

[0022] Furthermore, the inner cavity of the steel sleeve is a stepped hole structure and the stepped surface therein is the isolation portion.

[0023] A shock absorber piston rod welding method using any of the above-mentioned automobile shock absorber piston rod welding tools comprises the following steps:

[0024] S1, inserting the upper end of the electrode body of the welding tool into the mounting groove of the electrode holder and making the protrusion fit with the lower end surface of the electrode holder, and fastening the electrode to the electrode holder by passing a bolt through the mounting through hole of the protrusion;

[0025] S2, inserting the upper end of the threaded section of the threaded rod into the threaded rod positioning cavity of the welding tool, so that the magnetic suction block attracts the threaded rod to move to the upper limit position;

[0026] S3, starting the welding device, the electrode seat drives the welding tool and the threaded rod to move downward synchronously so that the welding section of the threaded rod is in close contact with the piston rod body;

[0027] S4, the electrode holder is powered on and continuously pressurized until the welding section and the piston rod body are hot-melt welded and the electrode holder is powered off;

[0028] S5. The electrode holder drives the welding tool to reset.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows: providing a welding tool for the piston rod of an automobile shock absorber, by arranging a steel sleeve in the electrode body so that the inner cavity of the steel sleeve and the lower column cavity of the electrode body are arranged adjacent to each other up and down to form a threaded rod positioning cavity, improving the rigidity and strength of the upper side wall of the threaded rod positioning cavity, avoiding the compression deformation or damage of the inner wall of the steel sleeve during the pressurized welding of the piston rod, extending the service life of the entire welding tool, improving production efficiency, and saving production costs; reducing the influence of electrode deformation of copper alloy material on the positioning accuracy of the threaded rod, improving the radial positioning accuracy of the threaded rod, ensuring the welding coaxiality between the threaded rod and the piston rod body, and improving the welding quality of the piston rod. By setting the threaded rod positioning piece as a magnetic suction block, the operator can quickly and labor-savingly complete the assembly and disassembly of the piston rod, improve work efficiency, save manpower, improve the quality of welding operations, extend the service life of the welding tool, and further save production costs. A shock absorber piston rod welding method is provided, by using the automobile shock absorber piston rod welding tool with a magnetic suction block in the present invention to quickly and labor-savingly complete the assembly and disassembly of the threaded rod, improve the work efficiency of welding operations, and save manpower. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of a piston rod in the background technology;

[0031] Figure 2 It is a schematic diagram of the axial cross-sectional structure of the welding tool in the present invention;

[0032] Figure 3 It is a schematic diagram of the assembly structure of the welding tool and the electrode holder of the present invention;

[0033] Figure 4 It is a schematic diagram of the cross-sectional structure of the welding tool during welding operation in the present invention;

[0034] Figure 5 yes Figure 2 A schematic diagram of the axial cross-sectional structure of the middle electrode 1;

[0035] Figure 6 It is a schematic diagram of the axial cross-sectional structure of the steel sleeve;

[0036] Figure numerals: 1-electrode; 11-electrode body; 12-protrusion; 2-steel sleeve; 21-upper cavity; 22-lower cavity; 23-isolating portion; 3-magnetic block; 41-upper column cavity; 42-lower column cavity; 5-fastening screw; 8-electrode seat; 81-mounting groove; 91-piston rod body; 92-threaded section; 93-welding section. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with the accompanying drawings and embodiments. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0038] As attached Figure 1-6 As shown, a welding tool for a piston rod of an automobile shock absorber comprises an electrode 1 made of copper alloy, the electrode 1 comprises an electrode body 11 of a cylindrical structure and a protrusion 12 arranged on the outer side wall of the lower part of the electrode body 11; the electrode body 11 is provided with an upper column cavity 41 with an opening facing upward and a lower column cavity 42 with an opening facing downward, the upper column cavity 41 and the lower column cavity 42 are arranged adjacent to each other up and down and have a first step surface at the adjacent position, the outer diameter of the upper column cavity 41 is greater than the outer diameter of the lower column cavity 42; the upper column cavity 41, the lower column cavity 42 and the electrode body 11 are arranged coaxially, and the protrusion 12 is provided with an axially penetrating mounting through hole; a steel sleeve 2 is fixedly arranged in the upper column cavity 41, and the inner cavity of the steel sleeve 2 is arranged coaxially and adjacently with the lower column cavity 42 to form a threaded rod positioning cavity; and a threaded rod positioning member for axially positioning the threaded rod is also included. The step surface between the upper column cavity 41 and the lower column cavity 42 is perpendicular to the axis of the electrode 1 and supports the steel sleeve 2 upward to limit the axial position of the steel sleeve 2. The electrode body 11 is generally made of copper alloy. The axial size of the threaded rod positioning cavity can be changed by changing the length of the steel sleeve 2 and the lower column cavity 42, thereby meeting the welding operation requirements of threaded rods with thread segments 92 of different lengths.

[0039] When in use, the upper part of the electrode body 11 and the steel sleeve 2 of the welding tool of the present invention are inserted into the mounting groove of the electrode holder 8, the side wall of the mounting groove of the electrode holder 8 fits with the outer side surface of the electrode body 11 to radially position the electrode 1, and the protrusion 12 is located outside the mounting groove of the electrode holder 8. The electrode 1 is installed on the electrode holder 8 by passing through the mounting through hole of the protrusion 12 with a bolt so that the protrusion 12 fits with the lower end surface of the electrode holder 8, thereby completing the fixed assembly of the electrode 1 and the entire welding tool.

[0040] During welding, the threaded section 92 on the threaded rod is completely located in the threaded rod positioning cavity, the side wall of the threaded rod positioning cavity fits with the outer wall of the threaded section 92 to radially position the threaded rod, the shoulder between the threaded section 92 and the welding section 93 fits with the lower end surface of the electrode body 11, and the threaded rod positioning piece positions and installs the threaded rod in the threaded rod positioning cavity. The piston rod body 91 is clamped under the threaded rod and is coaxial with the threaded rod. The electrode holder 8 drives the welding fixture and the threaded rod to move downward synchronously. After the welding protrusions of the welding section 93 and the piston rod body 91 are tightly abutted, the electrode holder 8 is energized to start welding. During the resistance welding pressurization process, the threaded rod will squeeze the side wall of the threaded rod positioning cavity after being compressed, that is, the threaded rod will squeeze the side wall of the lower column cavity 42 in the electrode body 11 and the inner wall of the steel sleeve 2. Because the rigidity and hardness of the steel sleeve 2 are relatively large, even if the side wall of the lower column cavity 42 of the electrode body 11 is squeezed and deformed by the threaded rod, the steel sleeve 2 will not be compressed and deformed. The inner wall of the steel sleeve 2 continues to support the side wall of the threaded rod for radial positioning, thereby preventing the threaded rod from deviating from the preset position and affecting the positioning accuracy, ensuring the welding coaxiality of the threaded rod and the piston rod body 91, ensuring the welding accuracy of the threaded rod, and improving the welding quality of the piston rod; at the same time, the welding tooling will not fail frequently, thereby extending the service life of the welding tooling, improving production efficiency, and saving production costs.

[0041] The electrode 1 is used to accurately position and install the entire welding fixture on the electrode holder 8. Its outer side wall is connected to the electrode holder 8, and its inner side wall is connected to the threaded rod, ensuring that the electrode holder 8 and the threaded rod are electrically conductive, meeting the necessary conditions for resistance welding operations. The side wall of the mounting groove of the electrode holder 8 fits with the outer side wall of the electrode body 11 to radially position the electrode 1, and then radially position the electrode body 1, the steel sleeve 2, the threaded rod positioning cavity and the piston rod body 91 to ensure that the threaded rod in the threaded rod positioning cavity is coaxial with the piston rod body 91. The protrusion 12 is used to fix the electrode 1 on the electrode holder 8 and fit with the lower end surface of the electrode holder 8 to axially position the electrode 1. The protrusion 12 can be a single limiting plate or a plurality of limiting plates evenly distributed along the circumference of the electrode body 11. Preferably, the protrusion 12 is a limiting ring plate coaxially arranged with the electrode body 11, which has a simple structure and is convenient for processing and manufacturing. One or more mounting holes may be provided on the protrusion 12. As a further preference, at least two mounting holes are provided on the limiting ring plate, and at least two mounting holes are evenly distributed along the circumference of the limiting ring plate to improve the installation reliability of the welding tooling.

[0042] The upper column cavity 41 is used to assemble the steel sleeve 2 and position it radially. The steel sleeve 2 can be directly welded or threaded in the upper column cavity 41, or it can be installed in the upper column cavity 41 through connectors such as top screws and elastic pins. Considering that the electrode body 11 is made of copper alloy, has low hardness and is easy to deform, it is easy to slip when it is threaded with the steel cylinder 2 or a commonly used steel screw. Specifically, the outer contour of the cross section of the upper column cavity 41 is adapted to the shape and size of the outer contour of the cross section of the steel sleeve 2, and the outer side surface of the steel sleeve 2 fits the side wall of the upper column cavity 41; a plurality of radial through holes are provided on the side wall of the electrode body 11, and the plurality of radial through holes are evenly distributed along the circumference of the electrode body 11; a threaded positioning hole coaxial with the radial through hole is provided on the outer wall of the steel sleeve 2, and a fastening screw 5 is provided in the radial through hole, and the fastening screw 5 is threadedly connected to the threaded positioning hole on the steel sleeve 2. The outer end surface of the fastening screw 5 is located in the radial through hole of the electrode body 11, and the threaded positioning hole on the steel sleeve 2 cannot penetrate the side wall of the steel sleeve 2 to avoid crushing the threads on the threaded section 92. The shape and size of the cross-sectional outer contour of the upper column cavity 41 and the cross-sectional outer contour of the steel sleeve 2 are adapted to each other, which means that the outer wall of the upper column cavity 41 cooperates with the side wall of the steel sleeve 2 to radially position the steel sleeve 2. The steel sleeve 2 is axially positioned on the electrode body 11 by the fastening screw 5, and the assembly and disassembly of the steel sleeve 2 is achieved by installing and removing the fastening screw 5, which is more stable and reliable.

[0043] The lower column cavity 42 is mainly used to accommodate the threaded section 92 of the threaded rod, and the side wall of the lower column cavity 42 fits with the outer wall of the threaded section 92 to limit the radial position of the threaded rod. Preferably, the lower column cavity 42 is a stepped hole, and the large hole of the stepped hole is located below the small hole of the stepped hole; the inner cavity of the steel sleeve 2 and the small hole of the stepped hole are coaxially arranged adjacent to form a threaded rod positioning cavity; the large hole of the stepped hole is used to accommodate the welding section 93 of the threaded rod and its depth is less than the axial length of the welding section 93. When clamping the threaded rod, the large hole of the stepped hole is used to guide the threaded rod into the threaded rod positioning cavity, assisting the operator to quickly and labor-savingly complete the clamping of the threaded rod. During welding, the fusion section 93 of the threaded rod is located in the large hole of the lower column cavity 42 and its welding end face protrudes downward from the lower end face of the electrode 1. The shoulder between the threaded section 92 and the fusion section 93 abuts against the step surface of the lower column cavity 42 to ensure that the threaded rod is installed in place so that the threaded section 92 is completely located in the threaded rod positioning cavity. During the resistance welding pressurization process, the step surface conducts electricity while also providing axial pressure to the threaded rod.

[0044] The steel sleeve 2 is used to maintain the radial positioning of the threaded rod. The steel sleeve 2 can be completely located in the upper column cavity 41, or partially located in the upper column cavity 41. To facilitate the installation and removal of the steel sleeve 2, as a further preferred embodiment, the steel sleeve 2 protrudes from the upper end surface of the electrode body 11.

[0045] The threaded rod positioning piece has a variety of structural forms, which can be a top screw or elastic top pin set on the inner wall of the electrode body 11, or a structure set on the lower end surface of the electrode 1 or an annular baffle, but these structures must ensure that the threaded rod is installed in place when clamping the threaded rod, which not only makes it easy for the threaded rod to fall, but also has more clamping action processes and consumes more manpower. Preferably, the threaded rod positioning piece is a magnetic suction block 3 set on the upper part of the steel sleeve 2, which has a simple structure and is convenient for processing and assembly. When clamping the threaded rod, it is only necessary to insert the upper end of the threaded rod into the lower column cavity 42 so that the magnetic suction block 3 attracts the threaded rod to move upward along its axial direction until the shoulder between the threaded section 92 and the welding section 93 abuts against the electrode body 11 to achieve the axial positioning of the threaded rod. In this process, the magnetic suction force of the magnetic suction block 3 assists the operator to complete the clamping of the threaded rod quickly and labor-savingly; after welding is completed, the piston rod and the piston rod body 91 are welded as one, and the electrode seat 8 drives the welding fixture to move upward to make the piston rod disengage. The piston rod can be assembled and disassembled quickly and labor-savingly, which improves work efficiency and saves manpower. In addition, the magnetic block 3 generally uses a permanent magnet, which does not rub against the side of the threaded rod, avoids scratches on the threaded section 92, improves the welding operation yield, and prolongs the life of the entire welding tooling.

[0046] The magnetic block 3 can be installed in the cavity of the steel sleeve 2 or outside the cavity of the steel sleeve 2. It can be directly bonded or adsorbed on the steel sleeve 2, or it can be installed on the steel sleeve 2 by threaded connection, bonding or pin connection. Preferably, an isolation part 23 is provided in the cavity of the steel sleeve 2, the upper part of the isolation part 23 is the upper cavity 21, and the lower part of the isolation part 23 is the lower cavity 22. The magnetic block 3 is located in the upper cavity 21 and adsorbed on the isolation part 23; the lower cavity 22 and the lower column cavity 42 are arranged adjacent to each other to form the threaded rod positioning cavity. Prevent the magnetic block 3 from deviating from the predetermined position or falling off, and improve the clamping reliability of the welding fixture. The isolation part 23 is used to install the magnetic block 3 to axially position the magnetic block 3. The isolation part 23 can be a ring plate structure, a step structure or other structures protruding from the inner wall of the steel sleeve 2. Preferably, the inner cavity of the steel sleeve 2 is a step hole structure and the step surface therein is the isolation part 23. The steel sleeve 2 has a simple structure and is convenient for processing and manufacturing.

[0047] A shock absorber piston rod welding method using any of the above-mentioned automobile shock absorber piston rod welding tools comprises the following steps:

[0048] S1, insert the upper end of the electrode body 11 of the welding tool into the mounting groove of the electrode holder 8 and make the protrusion 12 fit with the lower end surface of the electrode holder 8, and fasten the electrode 1 to the electrode holder 8 by passing the mounting through hole of the protrusion 12 with a bolt;

[0049] S2, inserting the upper end of the threaded section 92 of the threaded rod into the threaded rod positioning cavity of the welding tool, so that the magnetic block 3 attracts the threaded rod to move to the upper limit position;

[0050] S3, starting the welding device, the electrode holder 8 drives the welding tool and the threaded rod to move downward synchronously so that the welding section 93 of the threaded rod is in close contact with the piston rod body 91;

[0051] S4, the electrode holder 8 is powered on and continuously pressurized until the welding section 93 and the piston rod body 91 are hot-melt-welded and the electrode holder 8 is powered off;

[0052] S5. The electrode holder 8 drives the welding tool to reset.

[0053] The welding jig in steps S1-S5 refers to the automobile shock absorber piston rod welding jig. Step S1 is used to install the welding jig on the electrode holder 8. Step S2 is used to clamp and position the threaded rod on the welding jig. When the threaded rod is in the upper limit position, the shoulder between the threaded section 92 and the welding section 93 is axially abutted with the lower end face of the threaded rod positioning cavity to achieve positioning. The magnetic attraction of the magnetic block 3 can assist the operator to quickly and labor-savingly complete the clamping and positioning of the threaded rod, thereby improving the clamping efficiency. Step S3 is a pre-pressing operation before welding to ensure that the piston rod body 91 and the threaded rod are relatively pressed, and to ensure that the current passes through the workpiece after the electrode holder 8 in step S4 is energized. Step S4 is a welding operation. During the energization process, the piston rod body 91 and the threaded rod should be kept relatively pressed. The energization time and the pressurization time are adjusted as needed according to the welding volume and welding requirements to ensure that the welding between the fusion section 93 and the piston rod body 91 is solidified to a sufficient strength. The threaded rod in step S5 has been welded to the piston rod body 91. When the electrode holder 8 moves upward to reset, the upward pulling force of the electrode holder 8 is greater than the magnetic attraction force of the magnetic block 3 on the threaded rod, so that the threaded rod automatically comes out during the process of the electrode holder 8 driving the welding fixture to reset. Finally, only the threaded rod and the piston rod body 91 welded together need to be removed, which eliminates the disassembly operation of the threaded rod, saves manpower, and improves work efficiency.

[0054] The words "upper", "lower", "top" and "bottom" used in the present invention to indicate positions are relative positions and cannot be understood as limiting specific positions. The embodiments of this specific implementation method are all preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made according to the structure, shape and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A welding tool for a piston rod of an automobile shock absorber, comprising an electrode (1) made of a copper alloy, characterized in that: The electrode (1) comprises an electrode body (11) of a cylindrical structure and a protrusion (12) arranged on the lower outer side wall of the electrode body (11); The electrode body (11) is provided with an upper column cavity (41) with an opening facing upward and a lower column cavity (42) with an opening facing downward, the upper column cavity (41) and the lower column cavity (42) are arranged adjacent to each other up and down and have a first step surface at the adjacent position, the outer diameter of the upper column cavity (41) is greater than the outer diameter of the lower column cavity (42); the upper column cavity (41), the lower column cavity (42) and the electrode body (11) are arranged coaxially, and the protruding portion (12) is provided with an axially penetrating mounting through hole; A steel sleeve (2) is fixedly arranged in the upper column cavity (41), and the inner cavity of the steel sleeve (2) is coaxially arranged adjacent to the lower column cavity (42) to form a threaded rod positioning cavity; and a threaded rod positioning member for axially positioning the threaded rod is also included.

2. The automobile shock absorber piston rod welding tool according to claim 1, characterized in that: The protruding portion (12) is a limiting ring plate coaxially arranged with the electrode body.

3. The automobile shock absorber piston rod welding tool according to claim 2, characterized in that: At least two mounting through holes are arranged on the limiting ring plate, and the at least two mounting through holes are evenly distributed along the circumference of the limiting ring plate.

4. The automobile shock absorber piston rod welding tool according to claim 1, characterized in that: The cross-sectional outer contour of the upper column cavity (41) is adapted to the shape and size of the cross-sectional outer contour of the steel sleeve (2), and the outer side surface of the steel sleeve (2) is in contact with the side wall of the upper column cavity (41); A plurality of radial through holes are provided on the side wall of the electrode body (11), and the plurality of radial through holes are evenly distributed along the circumference of the electrode body (11); a threaded positioning hole coaxial with the radial through hole is provided on the outer wall of the steel sleeve (2), a fastening screw (5) is provided in the radial through hole, and the fastening screw (5) is threadedly connected to the threaded positioning hole on the steel sleeve (2).

5. The automobile shock absorber piston rod welding tool according to claim 1, characterized in that: The lower column cavity (42) is a stepped hole, and the large hole of the stepped hole is located below the small hole of the stepped hole; The inner cavity of the steel sleeve (2) is coaxially arranged adjacent to the small hole of the step hole to form a threaded rod positioning cavity; the large hole of the step hole is used to accommodate the welding section (93) of the threaded rod and its depth is less than the axial length of the welding section (93).

6. The automobile shock absorber piston rod welding tool according to claim 4, characterized in that: The steel sleeve (2) protrudes from the upper end surface of the electrode body (11).

7. The automobile shock absorber piston rod welding tool according to any one of claims 1 to 6, characterized in that: The threaded rod positioning piece is a magnetic attraction block (3) arranged on the upper part of the steel sleeve (2).

8. The automobile shock absorber piston rod welding tool according to claim 7, characterized in that: An isolation portion (23) is provided in the cavity of the steel sleeve (2); an upper cavity (21) is located above the isolation portion (23); a lower cavity (22) is located below the isolation portion (23); the magnetic block (3) is located in the upper cavity (21) and is adsorbed on the isolation portion (23); the lower cavity (22) and the lower column cavity (42) are arranged adjacent to each other in upper and lower directions to form the threaded rod positioning cavity.

9. The automobile shock absorber piston rod welding tool according to claim 8, characterized in that: The inner cavity of the steel sleeve (2) is a stepped hole structure, and the stepped surface therein is the isolation portion (23).

10. A shock absorber piston rod welding method using the automobile shock absorber piston rod welding tool as claimed in claim 7, characterized in that: Includes steps: S1. Insert the upper end of the electrode body (11) of the welding tool into the mounting groove of the electrode holder (8) and make the protrusion (12) fit with the lower end surface of the electrode holder (8), and fasten the electrode (1) to the electrode holder (8) by passing a bolt through the mounting through hole of the protrusion (12); S2, inserting the upper end of the threaded section (92) of the threaded rod into the threaded rod positioning cavity of the welding tool, so that the magnetic attraction block (3) attracts the threaded rod to move to the upper limit position; S3, starting the welding device, the electrode holder (8) drives the welding tool and the threaded rod to move downward synchronously so that the welding section (93) of the threaded rod is in close contact with the piston rod body (91); S4, the electrode holder (8) is powered on, and the electrode holder (8) is continuously pressurized until the welding of the welding section (93) and the piston rod body (91) is completed by hot-melt welding, and then the electrode holder (8) is powered off; S5. The electrode holder (8) drives the welding tool to reset.

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