Spot welding gun

Abstract

A spot welding gun, comprising: a welding gun head (11), which is provided with a first electrode (111) and a first electrode mounting arm (112) for bearing the first electrode (111), and a second electrode (113) and a second electrode mounting arm (114) for bearing the second electrode (113), the second electrode mounting arm (114) being rotatably connected to the first electrode mounting arm (112); a connecting device (12) having one end connected to the second electrode mounting arm (114) and the other end of the connecting device (12) joined with a power unit (13); the power unit (13), which is configured to drive the connecting device (12) so as to drive the second electrode mounting arm (114) and the second electrode (113); and a distance measurement unit (14), which is configured to obtain a lateral movement distance of the second electrode (113), so as to obtain the thickness of a workpiece to be measured. By means of the structural design of the welding gun head (11) of the spot welding gun, the thickness of a workpiece to be welded is measured, and the application range of the spot welding gun of an A-type structure is widened.

Description

A spot welding gun

[0001] This application claims priority to a Chinese patent application filed on September 19, 2023, with application number 2023225392355 and invention name “A spot welding gun”. The entire contents of this patent application are incorporated herein by reference. Technical Field

[0002] The present application relates to the field of welding technology, and in particular to a spot welding gun. Background Art

[0003] Spot welding is a welding process in which two or more workpieces to be welded are connected together at least at one point, for example, by a spot welding gun, and the tool used in the spot welding process is a spot welding gun. In an adaptive spot welding process, there is a pretreatment process for the workpiece to be welded before the formal spot welding process, that is, before the formal welding, the pollutants, oxide films, etc. on the surface of the workpiece to be welded are treated to reduce the resistance value of the surface of the workpiece to be welded, thereby improving the welding quality. In order to judge whether the pretreatment process is completed, one method is to first measure the thickness of the workpiece to be welded, set a resistance threshold based on the thickness of the workpiece to be welded, and judge whether the pretreatment is completed based on whether the resistance value measured during the pretreatment process is lower than the predetermined resistance threshold. However, a current A-type (or X-type) structure spot welding gun does not have a thickness measuring function, which limits the application of this type of spot welding gun. Therefore, it is necessary to develop a spot welding gun with an A-type structure that can measure the thickness of the workpiece to be welded.

[0004] Summary of the Invention

[0005] In view of this, an object of the present application is to provide a spot welding gun with an A-type structure capable of measuring the thickness of a workpiece to be welded.

[0006] The present application provides a spot welding gun, including a welding gun head, which is configured with: a first electrode and a first electrode mounting arm for carrying the first electrode; a second electrode and a second electrode mounting arm for carrying the second electrode, the second electrode mounting arm being rotatably connected to the first electrode mounting arm, and a workpiece to be welded can be clamped between the first electrode and the second electrode; a connecting device, one end of which is connected to the second electrode mounting arm, and the other end of which is combined with a power unit; the power unit is used to drive the connecting device, and then drive the second electrode mounting arm and the second electrode; a distance measuring unit is used to obtain the distance the second electrode moves lateraly before and after the workpiece to be welded is clamped between the first electrode and the second electrode, and then obtain the thickness of the workpiece to be welded.

[0007] According to an exemplary embodiment, the second electrode mounting arm includes a first portion substantially perpendicular to the first electrode mounting arm and a second portion opposite to the first electrode mounting arm, and the connecting device is located at a junction of the first portion and the second portion.

[0008] According to an exemplary embodiment, an opening is configured at a junction of the first portion and the second portion of the second electrode mounting arm, and the opening extends a certain length along a length direction of the first portion of the second electrode mounting arm.

[0009] According to an exemplary embodiment, the connecting device is configured with a coupling shaft and a through hole, and the coupling shaft passes through the through hole and the opening in sequence to achieve connection between the connecting device and the second electrode mounting arm.

[0010] According to an exemplary embodiment, the distance measuring unit includes a measuring device and a processing module; the measuring device is used to measure the axial movement distance S0 of the power unit corresponding to the lateral movement of the second electrode from the first position to the second position St; the processing module is electrically connected to the measuring device, and the processing module is used to obtain the lateral movement distance of the second electrode based on the axial movement distance S0 measured by the measuring device and the quantitative relationship between the internally stored axial movement distance of the power unit and the lateral movement distance of the second electrode, thereby obtaining the thickness of the workpiece to be welded.

[0011] According to an exemplary embodiment, the measuring device is a capacitive barrier sensor, and a moving barrier of the capacitive barrier sensor is physically connected to the power unit.

[0012] According to an exemplary embodiment, the first electrode mounting arm and the first electrode, the second electrode mounting arm and the second electrode, and the connecting device are made of conductive materials.

[0013] According to an exemplary embodiment, the spot welding gun further includes an electrical connection wire, one end of the electrical connection wire is fixedly connected to the second electrode mounting arm, and the other end of the electrical connection wire is fixedly connected to the connection device.

[0014] According to an exemplary embodiment, the power unit is a pneumatic cylinder.

[0015] According to an exemplary embodiment, the first electrode mounting arm and the second electrode mounting arm are insulated from each other.

[0016] The spot welding gun provided in an embodiment of the present application includes a connecting device, one end of which is connected to the second electrode mounting arm, and the other end of which is coupled to the power unit; the second electrode mounting arm of the spot welding gun is configured to be rotatably connected to the first electrode mounting arm, so that the axial power output by the power unit first drives the connecting device, and then drives the second electrode mounting arm, and the second electrode mounting arm is rotatable relative to the first electrode mounting arm, and then the rotation of the second electrode mounting arm drives the lateral movement of the second electrode, thereby the axial movement output by the power unit is ultimately converted into the lateral movement of the second electrode. The distance measuring unit measures the axial movement distance S0 of the power unit corresponding to the lateral movement distance St of the second electrode from the first position to the second position before and after clamping the workpiece to be welded, and then obtains the lateral movement distance of the second electrode based on the quantitative relationship between the axial movement distance of the power unit and the lateral movement distance of the second electrode, thereby obtaining the thickness of the workpiece to be welded. The spot welding gun provided in an embodiment of the present application realizes the measurement of the thickness of the workpiece to be welded through the structural design of the welding gun head, which broadens the application range of this A-type structure spot welding gun. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG1 is a schematic diagram of the overall structure of a spot welding gun provided in one embodiment of the present application;

[0018] Figure 2 is a schematic diagram of the overall structure of the welding gun head with the connecting device installed;

[0019] FIG3 is an exploded view of the welding gun head with the connecting device installed;

[0020] Figures 4a and 4b are schematic diagrams of the combined shaft sliding in the opening before and after;

[0021] FIG5 is a schematic diagram of the second electrode moving from the first position to the second position. DETAILED DESCRIPTION

[0022] The present application will be fully described below with reference to the accompanying drawings. However, it should be understood that the exemplary embodiments disclosed in this application are for the purpose of facilitating a thorough understanding of this application, and these exemplary embodiments should be understood as merely illustrative and not restrictive.

[0023] FIG1 is a schematic diagram of the overall structure of a spot welding gun provided by an embodiment of the present application. As shown in FIG1 , the spot welding gun includes a welding gun head 11, a connecting device 12, a power unit 13, and a distance measuring unit 14. The welding gun head 11 is configured with a first electrode 111 and a first electrode mounting arm 112 for carrying the first electrode 111; a second electrode 113 and a second electrode mounting arm 114 for carrying the second electrode 113, wherein the second electrode mounting arm 114 is rotatably connected to the first electrode mounting arm 112, and the workpiece to be welded can be clamped between the first electrode 111 and the second electrode 113; one end of the connecting device 12 is connected to the second electrode mounting arm 114, and the other end of the connecting device 12 is combined with the power unit 13; the power unit 13 is used to drive the connecting device 12, thereby driving the second electrode mounting arm 114 and the second electrode 113; the distance measuring unit 14 is used to obtain the distance that the second electrode 113 moves lateral to the workpiece 20 to be welded before and after it is clamped between the first electrode 111 and the second electrode 113, thereby obtaining the thickness of the workpiece to be welded.

[0024] Specifically, Figure 2 is a schematic diagram of the overall structure of the welding gun head with the connection device installed, and Figure 3 is an exploded schematic diagram of the welding gun head with the connection device installed. Referring to Figures 2 and 3, the second electrode mounting arm 114 includes a first portion 1141 that is approximately perpendicular to the first electrode mounting arm 112 and a second portion 1142 that is opposite the first electrode mounting arm 112. The connection device 12 is located at the junction of the first portion 1141 and the second portion 1142 of the second electrode mounting arm 114. One end of the first portion 1141 of the second electrode mounting arm 114 is rotatably connected to the first electrode mounting arm 112, for example, by the cooperation of a metal pin and a retaining spring. It will be understood that in order to pass electricity to achieve resistance welding, the first electrode mounting arm 112 and the first electrode 111, the second electrode mounting arm 114 and the second electrode 113, and the connection device 12 are made of conductive materials. In addition, to prevent short circuits, the first electrode mounting arm 112 and the second electrode mounting arm 114 are insulated. In order to achieve insulation between the first electrode mounting arm 112 and the second electrode mounting arm 114, for example, an insulating sleeve can be provided on the rotating bolt outer shell and an insulating gasket can be used. Of course, other methods of achieving insulation between the first electrode mounting arm 112 and the second electrode mounting arm 114 can also be used.

[0025] In one embodiment of the present application, in order to strengthen the electrical connection between the second electrode mounting arm 114 and the connecting device 12, the spot welding gun also includes an electrical connecting wire 15, one end of the electrical connecting wire 15 is fixed to the second electrode mounting arm 114 through a conductive fixing member, for example, it is fixed to the first part 1141 of the second electrode mounting arm 114, and the other end of the electrical connecting wire 15 is fixed to the connecting device 12 through a conductive fixing member.

[0026] The connecting device 12 includes a connecting rod 121, a main body 122, and a coupling shaft 123. The connecting rod 121 is, for example, a cylindrical metal rod, but this is not limiting. The connecting rod 121 may also be a prismatic or other shape. A receiving hole 125 is defined on one side of the main body 122. One end of the connecting rod 121 is received in the receiving hole 125 and then secured with a fastener. This is not limiting, and the connecting rod 121 may also be received in the receiving hole 125 using other means, such as an interference fit. The other end of the connecting rod 121 is coupled to the power unit 13. Specifically, for example, threads are provided at the end of the connecting rod 121, and corresponding threads are provided at the junction of the power unit 13 and the connecting rod 121, thereby tightening the connecting rod 121 and the power unit 13 together. A pair of flanges 126 extend outwardly and parallel from the upper and lower ends of the body 122, facing away from the receiving hole 125. The flanges 126 are spaced apart and each defines a coaxial through-hole 1261. An opening 124 is provided at the junction of the first portion 1141 and the second portion 1142 of the second electrode mounting arm 114. The opening 124 extends a predetermined length along the length of the first portion 1141 of the second electrode mounting arm 114. The coupling shaft 123, such as a metal pin, sequentially passes through the through-hole 1261 in the upper flange 126, the opening 124, and the through-hole 1261 in the lower flange 126. In conjunction with a retaining spring, the coupling device 12 is connected to the second electrode mounting arm 114. Since the opening 124 has a certain length, the coupling shaft 123 can slide in the opening 124 .

[0027] In the present application, because the opening 124 extends a certain length along the length direction of the first portion 1141 of the second electrode mounting arm 114, the power unit 13 drives the connecting rod 121, and the linear motion of the main body 122 along the axial direction can ultimately be converted into lateral movement of the second electrode 113. Specifically, the axial power output by the power unit 13 drives the connecting device 12, and thus drives the second electrode mounting arm 114. Because the second electrode mounting arm 114 can rotate relative to the first electrode mounting arm 112, and because the opening 124 has a certain length, the coupling shaft 123 can move from one end of the opening 124 to the other end along the extension direction of the opening. This is equivalent to extending the length of the first portion 1141 of the second electrode mounting arm 114, thereby allowing the second electrode mounting arm 114 to rotate relative to the first electrode mounting arm 112, thereby driving the lateral movement of the second electrode 113. As a result, the axial motion output by the power unit 13 is ultimately converted into lateral movement of the second electrode 113. For details, please refer to Figures 4a and 4b, which are schematic diagrams of the coupling shaft before and after sliding within the opening. Those skilled in the art will readily understand that, since the length of the first portion 1141 of the second electrode mounting arm 114 is fixed and the power unit 13 can only move in a straight line, if the opening 124 is not a fixed length, when the power unit 13 drives the connecting device 12 to move in a straight line, since the length of the first portion 1141 of the second electrode mounting arm 114 is fixed, the structures of the first electrode mounting arm 112 and the second electrode mounting arm 114 are relatively fixed, and the second electrode mounting arm 114 will not be able to rotate under the drive of the connecting device 12, resulting in the second electrode 113 being unable to approach or move away from the first electrode 111, and thus unable to clamp the workpiece to be welded, that is, the spot welding gun cannot operate. It is understood that in order to prevent the coupling shaft 123 from heating due to poor contact caused by sliding within the opening, the surface of the coupling shaft 123 can be covered with an insulating jacket, for example, or the coupling shaft 123 can be made of an insulating material.

[0028] The power unit 13 is, for example, a cylinder, which is used to push an object to move in a straight line, specifically in a straight line along the axial direction of the piston rod. Specifically, in a spot welding gun provided in one embodiment of the present application, the connecting rod 121 of the connecting device 12 is connected to the power unit 13, so that the power unit 13 drives the connecting rod 121 to move in the axial direction of the piston rod of the power unit 13. Since the connecting device 12 is connected to the second electrode mounting arm 114, and the second electrode mounting arm 114 can rotate relative to the first electrode mounting arm 112, under the driving action of the power unit 13, the axial rotation output by the power unit 13 is eventually converted into the rotation of the second electrode mounting arm 114 relative to the first electrode mounting arm 112. The rotation of the second electrode mounting arm 114 then drives the second electrode 113 to move laterally. Among them, the so-called axial movement refers to the movement of the power unit in the axial direction, and the lateral movement refers to the movement roughly perpendicular to the axial direction.

[0029] The ranging unit 14 includes a measuring device 141 and a processing module 142. The measuring device 141 is used to measure the axial movement distance S0 of the power unit (for example, a cylinder piston rod) corresponding to the lateral movement distance St of the second electrode from the first position to the second position (it should be noted that the axial movement distance of the power unit is equal to the axial movement distance of the connecting device. For the sake of convenience, the axial movement distance of the connecting device is used as an illustration in Figure 5).

[0030] FIG5 is a schematic diagram of the movement of the second electrode before and after clamping the workpiece to be welded. Referring to FIG5 , for example, before clamping the workpiece 20 to be welded, when the power unit 13 drives the second electrode 113 to contact the first electrode 111 with a certain pressure, the position of the second electrode 113 can be determined as the first position; and after clamping the workpiece 20 to be welded, when the power unit drives the second electrode 113 to contact the workpiece 20 to be welded with the same pressure, the position of the second electrode 113 can be determined as the second position. It is easy to understand that the lateral distance St that the second electrode 113 moves from the first position to the second position is the thickness of the workpiece 20 to be welded. Those skilled in the art will readily understand that when the second electrode 113 moves lateral distance St from the first position to the second position, the piston rod of the cylinder moves a corresponding distance S0 in the axial direction, and the lateral movement distance St of the second electrode 113 and the axial movement distance S0 of the cylinder piston rod satisfy a certain quantitative relationship. The measuring device 141 is used to measure the axial movement distance S0 of the power unit (eg, cylinder piston rod) corresponding to the lateral movement distance St of the second electrode 113 from the first position to the second position.

[0031] When the second electrode 113 is in the first position, correspondingly, in the axial direction, the piston rod of the cylinder is in one position, and when the second electrode 113 moves laterally to the second position, in the axial direction, the piston rod of the cylinder moves to another position. The lateral movement distance St of the second electrode 113 and the axial movement distance S0 of the power unit (such as the cylinder piston rod) satisfy a certain quantitative relationship, and this quantitative relationship can be obtained by fitting through multiple measurements, or can be obtained by theoretical calculation. Thereafter, by measuring the axial movement distance S0 of the cylinder piston rod, the lateral movement distance St of the second electrode can be inferred, thereby obtaining the thickness of the workpiece to be welded. In addition, the pressure during contact can be detected by setting a force detector or a pressure sensor to ensure that the pressure of the second electrode 113 in contact with the first electrode 111 is consistent with the pressure of the second electrode 113 in contact with the workpiece 20 to be welded, thereby improving the accuracy of the measured value.

[0032] The processing module 142 is electrically connected to the measuring device 141, and is used to obtain the thickness of the workpiece 20 to be welded based on the axial movement distance S0 of the cylinder piston rod measured by the measuring device 141 and the quantitative relationship between the axial movement distance of the power unit and the lateral movement distance of the second electrode stored internally.

[0033] Specifically, the measuring device 141 is, for example, a capacitive gate sensor, the movable gate of the capacitive gate sensor is physically connected to the power unit 13, specifically, for example, the movable gate is connected to the piston rod of the cylinder, thereby measuring the axial movement distance S0. The measuring device 141 transmits the measured data to the processing module 142, which is, for example, a microcontroller unit (MCU). The processing module 142 internally stores the quantitative relationship between the axial movement distance of the power unit (e.g., the cylinder piston rod) and the lateral movement distance of the second electrode 113. The processing module 142 calculates the lateral movement distance of the second electrode 113 based on the axial movement distance S0 of the power unit measured by the measuring device 141 and the quantitative relationship between the axial movement distance of the power unit and the lateral movement distance of the second electrode stored internally, thereby obtaining the thickness of the workpiece 20 to be welded. The quantitative relationship between the axial movement distance of the power unit 13 and the lateral movement distance of the second electrode 113 stored internally in the processing module 142 can be obtained, for example, by fitting multiple measurements, or can also be obtained by theoretical calculation.

[0034] The process of measuring the thickness of the workpiece to be welded is, for example, before the workpiece to be welded is clamped between the first electrode 111 and the second electrode 113, the power unit 13 drives the second electrode 113 to contact the first electrode 111 with a certain pressure, thereby determining the first position. Thereafter, the workpiece 20 to be welded is clamped between the first electrode 111 and the second electrode 113, and then the power unit 13 drives the second electrode 113 to contact the workpiece to be welded with the same pressure. At this time, the second electrode 113 moves a certain distance laterally to the second position. It can be understood that the distance that the second electrode 113 moves laterally from the first position to the second position is the thickness St of the workpiece to be welded. During the process of the second electrode 113 moving from the first position to the second position, the piston rod of the power unit correspondingly moves from one position to another position along its axial direction, and the distance moved is S0. The measuring device is connected to the piston rod to measure the axial movement distance S0 of the power unit (for example, the cylinder piston rod) corresponding to the process of the second electrode 113 moving from the first position to the second position and the lateral movement distance St before and after clamping the welding workpiece; thereafter, the processing module 142 obtains the thickness of the workpiece to be welded based on the measured axial movement distance S0 of the power unit and the quantitative relationship between the axial movement distance of the power unit and the lateral movement distance of the second electrode stored internally.

[0035] The present invention provides a spot welding gun, wherein one end of the connecting device 12 of the spot welding gun is connected to the second electrode mounting arm 114, and the other end of the connecting device 12 is coupled to the power unit 13; the second electrode mounting arm 114 of the spot welding gun is configured to be rotatably connected to the first electrode mounting arm 112, so that the axial movement output by the power unit 13 first drives the connecting device 12, and then drives the second electrode mounting arm 114, and the second electrode mounting arm 114 is rotatable relative to the first electrode mounting arm 112, and the rotation of the second electrode mounting arm 114 drives the second electrode 113 to move laterally, thereby ultimately converting the axial movement output by the power unit 13 into the lateral movement of the second electrode 113. The distance measuring unit 14 measures the axial movement distance S0 of the power unit 13 corresponding to the lateral movement distance St of the second electrode 113 from the first position to the second position before and after clamping the workpiece 20 to be welded, and then obtains the lateral movement distance of the second electrode 113 based on the quantitative relationship between the axial movement distance of the power unit and the lateral movement distance of the second electrode, thereby obtaining the thickness of the workpiece to be welded. The spot welding gun provided in the embodiment of the present application realizes the measurement of the thickness of the workpiece to be welded through the structural design of the welding gun head, thereby broadening the application scope of this A-type structure spot welding gun.

[0036] In the above description, many specific details are set forth in order to fully understand the present application. However, the above description is only a preferred embodiment of the present application, and the present application can be implemented in many other ways different from those described herein, so the present application is not limited to the specific implementation disclosed above. At the same time, any person skilled in the art can make many possible changes and modifications to the technical solution of the present application using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present application, or modify it into an equivalent embodiment of equivalent changes. Any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present application without departing from the content of the technical solution of the present application still falls within the scope of protection of the technical solution of the present application.

Claims

1. A spot welding gun, characterized in that: include: A welding gun head, the welding gun head being configured with: a first electrode and a first electrode mounting arm for carrying the first electrode; A second electrode and a second electrode mounting arm for carrying the second electrode, the second electrode mounting arm being rotatably connected to the first electrode mounting arm, and a workpiece to be welded can be clamped between the first electrode and the second electrode; A connecting device, one end of which is connected to the second electrode mounting arm, and the other end of which is combined with the power unit; A power unit, used to drive the connecting device, and then drive the second electrode mounting arm and the second electrode; The distance measuring unit is used to obtain the lateral movement distance of the second electrode before and after the workpiece to be welded is clamped between the first electrode and the second electrode, thereby obtaining the thickness of the workpiece to be welded.

2. The spot welding gun according to claim 1, characterized in that: The second electrode mounting arm includes a first portion substantially perpendicular to the first electrode mounting arm and a second portion opposite to the first electrode mounting arm, and the connecting device is located at the junction of the first portion and the second portion.

3. The spot welding gun according to claim 2, characterized in that: An opening is arranged at the junction of the first portion and the second portion of the second electrode mounting arm, and the opening extends a certain length along the length direction of the first portion of the second electrode mounting arm.

4. The spot welding gun according to claim 3, characterized in that: The connecting device is provided with a coupling shaft and a through hole, and the coupling shaft passes through the through hole and the opening in sequence to achieve the connection between the connecting device and the second electrode mounting arm.

5. The spot welding gun according to claim 1, characterized in that: The distance measuring unit includes a measuring device and a processing module; The measuring device is used to measure the axial movement distance S0 of the power unit corresponding to the lateral movement distance St of the second electrode from the first position to the second position; The processing module is electrically connected to the measuring device, and is used to obtain the lateral movement distance of the second electrode based on the axial movement distance S0 measured by the measuring device and the quantitative relationship between the axial movement distance of the power unit and the lateral movement distance of the second electrode stored internally, thereby obtaining the thickness of the workpiece to be welded.

6. The spot welding gun according to claim 5, characterized in that: The measuring device is a capacitive grid sensor, and a moving grid of the capacitive grid sensor is physically connected to a power unit.

7. The spot welding gun according to claim 1, characterized in that: The first electrode mounting arm and the first electrode, the second electrode mounting arm and the second electrode, and the connecting device are made of conductive materials.

8. The spot welding gun according to claim 1, characterized in that: The spot welding gun further comprises an electrical connection line, one end of which is fixedly connected to the second electrode mounting arm, and the other end of which is fixedly connected to the connection device.

9. The spot welding gun according to claim 1, characterized in that: The power unit is a cylinder.

10. The spot welding gun according to claim 1, characterized in that: The first electrode mounting arm and the second electrode mounting arm are insulated from each other.

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