Demonstration positioning method and device for C-shaped spot welding pliers

Abstract

The invention relates to the technical field of welding, in particular to a C-shaped spot welding clamp teaching positioning method and device, and the method comprises the steps of calibration, position positioning, angle adjustment, teaching and data recording. A fixed side electrode cap in the device is fixed on a fixed side clamp arm of a spot welding clamp, and a movable side electrode cap is mounted at one end of a movable side electrode rod; the plurality of laser displacement sensors are fixedly arranged in the circumferential direction of the movable side electrode stem; and the laser positioning sensor is arranged on the spot welding clamp. The method has the advantages that visible light spots are formed on the surface of the to-be-welded material through the laser positioning sensor, the target welding position is visually indicated, it is not needed to repeatedly clamp electrodes for position testing, and the teaching positioning efficiency is improved; the multiple laser displacement sensors are used for detecting the distance difference between the welding tongs and the welding surface in real time, distance values output by the laser displacement sensors are consistent by adjusting the posture of the welding tongs, it is ensured that the end face of an electrode cap is parallel to the surface of a welding material, and the problem that traditional teaching depends on artificial experience is solved.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular to a C-shaped spot welding clamp teaching and positioning method and device. Background Technology

[0002] Robots are increasingly used in industry, especially in the automotive manufacturing sector, where spot welding robots are widely used for automated welding of car bodies and components. Depending on the welding position, spot welding robots typically employ C-shaped spot welding clamps. In practical operation, the following technical challenges exist when teaching a C-shaped spot welding clamp: 1. Low positioning efficiency: The teaching process requires repeatedly clamping the movable side electrode cap to position the welding point, resulting in cumbersome teaching steps, frequent adjustments, and low efficiency.

[0003] 2. Unstable welding quality: Because the electrode cap end face is often not parallel to the surface of the welding material, the weld point is skewed, which easily leads to defects such as welding spatter, reduced joint strength, and weld point cracks, and also affects the appearance of the weld.

[0004] 3. Adjustment relies on human experience: The electrode cap has a small end face diameter (usually only 6mm), making it difficult to accurately adjust its parallelism with the surface of the welding material by visual inspection alone. Repeated trial welding and adjustment of the welding clamp posture are required, which not only wastes a lot of workpieces and debugging time, but also fails to guarantee the stability and consistency of welding quality.

[0005] To address the spot welding positioning problem, several solutions have been proposed in the existing technology, such as: The invention patent, published under CN118875440A and entitled "An auxiliary positioning device and welding clamp for a handheld spot welding machine", uses a mechanical stop to abut against the edge of the welding plate and guides the electrode to move along the edge trajectory of the plate to achieve weld point positioning. However, this solution is only applicable to mechanical positioning and not to the precise posture control of an automatic spot welding clamp. The invention patent, published under CN119910620A and entitled "X-type spot welding clamp teaching and positioning method, teaching and positioning device and spot welding robot", uses two laser spots to determine the welding position and angle. Although it solves the two-dimensional positioning problem to some extent, it does not solve the problem of adjusting the parallelism between the electrode cap end face and the surface of the welding material. Summary of the Invention

[0006] The purpose of this invention is to provide a C-shaped spot welding clamp teaching and positioning method and device. By setting up a laser positioning sensor, an indicator light spot is formed on the surface of the welding material to quickly locate the welding position, avoiding the problems of cumbersome repeated pressing of the electrode cap and low positioning accuracy in traditional methods. At the same time, based on the principle of multi-point ranging, multiple laser displacement sensors are used to detect the distance difference between the end face of the electrode cap and the welding surface in real time. By adjusting the posture of the welding clamp to make the measurement values ​​of each laser displacement sensor consistent, the end face of the electrode cap is ensured to be parallel to the surface of the welding material. This solves the problems of difficulty in determining the angle of the electrode cap, skewed weld points, and complex debugging during the welding process, thereby improving welding quality and efficiency.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A C-shaped spot welding clamp teaching and positioning method includes: S1, Calibration: The reference plate is placed between the fixed side electrode cap and the movable side electrode cap of the spot welding clamp and clamped. The measurement values ​​of each laser displacement sensor to the surface of the reference plate are obtained, and the measurement values ​​are set as the zero point of each laser displacement sensor. S2, Location Positioning: Move the spot welding clamp so that the laser spot formed by the laser positioning sensor on the surface of the material to be welded is located at the target welding position; S3, Angle Adjustment: Centered on the target welding position, adjust the posture of the spot welding clamp until the measurement values ​​displayed by each laser displacement sensor are consistent. At this time, the end face of the movable side electrode cap is parallel to the surface of the material to be welded. S4, Demonstration: Adjust the position of the spot welding clamp so that the laser positioning sensor spot is aligned with the target welding position; S5, Data Recording: Record the position and orientation data of the spot welding clamp at this time as teaching data for the target welding point.

[0008] In S1, adjust each laser displacement sensor so that the emitted laser beam is parallel to the axis of the movable side electrode cap.

[0009] The reference plate is a flat steel plate.

[0010] A C-shaped spot welding clamp teaching and positioning device includes a spot welding clamp, a laser displacement sensor, and a laser positioning sensor. The spot welding clamp includes a fixed side electrode cap, a movable side electrode cap, and a movable side electrode rod. The fixed side electrode cap is fixed on the fixed side clamp arm of the spot welding clamp, and the movable side electrode cap is installed at one end of the movable side electrode rod. Multiple laser displacement sensors are fixedly arranged around the movable side electrode rod, and the direction of the laser beam emitted by the sensors is parallel to or has the same preset angle as the axis of the movable side electrode cap. A laser positioning sensor is mounted on the spot welding clamp to form a light spot on the surface of the material to be welded, indicating the welding position.

[0011] The spot welding pliers are C-shaped.

[0012] The laser emitted by the laser positioning sensor and the laser displacement sensor are different colors.

[0013] The laser positioning sensor forms a circular, ring-shaped, or cross-shaped light spot on the surface of the material to be welded.

[0014] The number of laser displacement sensors is ≥3.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. A visible light spot is formed on the surface of the material to be welded by a laser positioning sensor, which intuitively indicates the target welding position. There is no need to repeatedly clamp the electrode for trial positioning, which improves the efficiency and accuracy of teaching and positioning. Multiple laser displacement sensors are used to detect the distance difference between the welding clamp and the welding surface in real time. By adjusting the posture of the welding clamp, the distance values ​​output by each laser displacement sensor are consistent, ensuring that the end face of the electrode cap is parallel to the surface of the welding material. This effectively solves the problem that angle adjustment in traditional teaching relies on manual experience and is difficult to control precisely. 2. By controlling the parallelism between the electrode cap and the surface of the welding material, welding spatter, reduced joint strength, and crack defects caused by weld point misalignment can be effectively avoided, thereby improving the mechanical properties and appearance quality of the welded joint. It is particularly suitable for applications such as automotive body welding where high welding quality is required. 3. Through non-contact laser measurement and spot guidance, "one-time positioning and one-time leveling" is achieved, which greatly reduces the repeated pressing and welding tests of the workpiece during the traditional trial welding and debugging process, saves debugging time and material costs, and improves production efficiency; 4. The device only requires the addition of laser displacement sensors and laser positioning sensors to the existing C-shaped spot welding clamp. It does not require complex mechanical structures or major modifications to existing equipment. It is easy to integrate into industrial robot systems, and the operation process is highly visualized, reducing the technical threshold and labor intensity for operators. 5. This invention is not only applicable to C-shaped spot welding clamps, but its principle can also be extended to the positioning and attitude control of other types of welding clamps. By adjusting the layout and number of sensors, it can adapt to different welding scenarios and workpiece shapes, and has good engineering applicability and technical extensibility. 6. Multiple laser displacement sensors are arranged around the movable side electrode rod to simultaneously measure the distance between the electrode cap axis and the welding surface at multiple azimuth angles. This provides a comprehensive and real-time reflection of the parallelism deviation between the electrode cap end face and the welding material surface. By comparing the distance values ​​measured by each laser displacement sensor, it is possible to more accurately determine whether the electrode cap is parallel to the welding surface. If the values ​​are inconsistent, it indicates that there is a tilt. The operator or control system can then make precise posture corrections based on this, avoiding errors that may be caused by single-point measurements. 7. The laser displacement sensor is arranged circumferentially along the movable side electrode rod, which does not affect the normal movement and welding function of the electrode cap, and can realize multi-angle detection, making it easy to integrate into the existing C-shaped welding clamp structure. 8. By presetting the angle between the sensor laser beam and the electrode cap axis, different welding angles or workpiece shapes can be flexibly adapted, enhancing the system's adaptability and practicality; each sensor maintains a parallel or identical angle relationship with the electrode cap axis, facilitating the unified setting of measurement benchmarks during the calibration stage, making subsequent distance comparisons and attitude judgments more intuitive and convenient. Attached Figure Description

[0016] Figure 1 This is a schematic diagram showing the parallel state between the electrode end face and the surface of the welding material.

[0017] Figure 2 This is a schematic diagram of the laser spot on the surface of the welding material from the laser displacement sensor and the laser positioning sensor.

[0018] Figure 3 This is a schematic diagram showing the non-parallel state between the electrode end face and the welding material surface.

[0019] Figure 4 It's a picture of a misaligned solder joint.

[0020] Figure 5 These are pictures of normal solder joints.

[0021] In the figure: 1. C-type spot welding clamp; 2. Laser displacement sensor one; 3. Laser displacement sensor two; 4. Laser displacement sensor three; 5. Movable side electrode rod; 6. Laser positioning sensor; 7. Welding material; 8. Laser spot on the surface of the welding material by the laser displacement sensor; 9. Laser spot on the surface of the material to be welded by the laser positioning sensor; 10. Movable side electrode cap. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0023] The following embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise specified, the methods used in the following embodiments are conventional methods.

[0024] Example 1 See Figure 1 , Figure 3 A C-shaped spot welding clamp teaching and positioning device includes a C-shaped spot welding clamp 1, a laser displacement sensor 2, a laser displacement sensor 3, a laser displacement sensor 4, and a laser positioning sensor 6. The laser positioning sensor 6 emits a different color laser than the laser displacement sensors 2, 3, and 4. The C-shaped spot welding clamp 1 includes a fixed side electrode cap, a movable side electrode cap 10, and a movable side electrode rod 5. The fixed side electrode cap is fixed on the fixed side clamp arm of the C-shaped spot welding clamp 1, and the movable side electrode cap is installed at one end of the movable side electrode rod 5. The laser displacement sensors 2, 3, and 4 are fixedly arranged around the movable side electrode rod 5, and the direction of their emitted laser beams is parallel to or has the same preset angle as the axis of the movable side electrode cap 10. The laser positioning sensor 6 is disposed on the C-shaped spot welding clamp 1 and is used to form a light spot indicating the welding position on the surface of the material to be welded 7. The light spot formed by the laser positioning sensor 6 on the surface of the material to be welded 7 is circular, annular, or cross-shaped.

[0025] A C-shaped spot welding clamp teaching and positioning method includes: S1, Calibration: Place the flat steel plate between the fixed side electrode cap and the movable side electrode cap 10 of the C-type spot welding clamp 1 and clamp it. Turn on the power of the laser displacement sensor and obtain the measurement values ​​of laser displacement sensor 1 2, laser displacement sensor 2 3, and laser displacement sensor 3 4 to the surface of the flat steel plate. Set the measurement values ​​as the zero point of laser displacement sensor 1 2, laser displacement sensor 2 3, and laser displacement sensor 3 4. At this time, adjust the laser displacement sensor to zero and record it in the laser displacement sensor.

[0026] Adjust laser displacement sensor 1, laser displacement sensor 2, and laser displacement sensor 3 to make the emitted laser beam parallel to the axis of the movable side electrode cap 10.

[0027] Establish a measurement benchmark for the laser displacement sensors. By clamping a flat steel plate between two electrode caps, the state of contact between the electrode cap end face and an ideal plane is simulated. The distance values ​​from each laser displacement sensor to the steel plate surface at this time are obtained and set as zero points. This step ensures that in subsequent measurements, the sensor output values ​​can directly reflect the actual distance deviation between the electrode cap end face and the welding material surface, providing an accurate measurement benchmark for parallelism judgment.

[0028] S2, Location Positioning: Move the C-type spot welding clamp 1 so that the laser positioning sensor's spot 9 on the surface of the material to be welded is located at the target welding position.

[0029] By utilizing the laser spot formed on the surface of the welding material by a laser positioning sensor, the planar position of the target welding point can be quickly and intuitively determined. By moving the spot welding clamp to align the laser spot with the preset welding point position, precise positioning can be achieved without physical contact, replacing the traditional operation of repeatedly pressing electrodes together, thus improving positioning efficiency and accuracy.

[0030] S3, Angle Adjustment: The laser beam emitted by the laser displacement sensor irradiates the surface of the material to be welded 7, and the distance from the laser displacement sensor to the material to be welded 7 is obtained. The angle of the C-type spot welding clamp 1 is adjusted so that the values ​​obtained by the laser displacement sensor 1, laser displacement sensor 2, laser displacement sensor 3, and laser displacement sensor 4 are the same, which means that the end face of the movable side electrode cap 10 is parallel to the surface of the material to be welded 7.

[0031] By measuring distance values ​​in different directions using multiple laser displacement sensors, the parallelism between the electrode cap end face and the welding material surface is determined and adjusted. When all sensor output values ​​are consistent, it indicates that the electrode cap end face is parallel to the welding surface, thus ensuring uniform force on the electrode during welding, avoiding welding defects caused by angular misalignment, and improving welding quality and consistency.

[0032] S4, Demonstration: Turn on the power to the laser positioning sensor and the laser displacement sensor, adjust the spot welding clamp to be above the welding material, and the laser positioning sensor 6 forms a light spot on the material to be welded 7. The position of the light spot is the welding position. Adjust the position of the light spot to the required welding position to complete the positioning of the welding point.

[0033] The systematization of the positioning and angle adjustment process enables complete attitude teaching of the weld point. By simultaneously activating laser positioning and displacement sensors, the welding clamp is adjusted to the target position and attitude under visual guidance, completing the spatial positioning and angle calibration of the weld point, and providing accurate position and attitude parameters for subsequent automated welding.

[0034] S5, Data Recording: Record the position and orientation data of the C-type spot welding clamp 1 at this time as teaching data for the target welding point.

[0035] Save the adjusted position and attitude data of the spot welding clamp as the teaching program for that welding point. The recorded data can be used by the robot to automatically perform welding tasks, achieving repeatability and consistency in the welding process. It also supports continuous teaching of multiple welding points and completes the programming of the overall welding path.

[0036] Example 2 In this embodiment, a C-shaped spot welding clamp teaching and positioning method and device are the same as in Embodiment 1, with the addition of a working process.

[0037] A 6-joint robot drives a C-type spot welding clamp 1. Laser displacement sensor 1 (2), laser displacement sensor 2 (3), and laser displacement sensor 3 (4) are fixed to the movable electrode rod 5 of the C-type spot welding clamp 1 via mounting brackets. (See...) Figure 1 Adjust laser displacement sensors 1-2, 2-3, and 3-4 so that their emitted laser beams are parallel to the axis of the movable side electrode cap 10. Fix laser positioning sensor 6 to the servo electrode surface of the C-type spot welding clamp 1 and adjust its angle so that its laser spot is located at the center of the projection of the movable side electrode cap 10. Figure 2 .

[0038] Take a flat steel plate with a thickness of 1mm, place it between the fixed side electrode cap and the movable side electrode cap 10, and clamp it. At this time, read the values ​​of laser displacement sensor 12, laser displacement sensor 23, and laser displacement sensor 34, and set them as zero points. See Figure 2 Complete the calibration of C-type spot welding clamp 1.

[0039] When welding workpieces, see Figure 3 First, the welding position is determined based on the laser positioning sensor 6. Then, using the welding position as a reference, the angle of the C-type spot welding clamp 1 is adjusted so that the data displayed by laser displacement sensors 1-2, 2-3, and 3-4 are consistent. At this time, the C-type spot welding clamp is perpendicular to the surface of the material to be welded 7, and the end face of the movable side electrode cap 10 is parallel to the surface of the material to be welded 7. See [link / description]. Figure 1 Record the position data of the C-type spot welding clamp 1 at this time. Determine the welding position and angle data of subsequent welding points in sequence according to this method. After all welding point data is recorded, the teaching of the C-type welding clamp is completed.

[0040] This invention uses a laser positioning sensor to form a visible light spot on the surface of the material to be welded, intuitively indicating the target welding position. This eliminates the need for repeated electrode clamping for trial positioning, improving the efficiency and accuracy of teaching and positioning. Multiple laser displacement sensors detect the distance difference between the welding clamp and the welding surface in real time. By adjusting the welding clamp posture to ensure consistent distance values ​​from each laser displacement sensor, the electrode cap end face is kept parallel to the welding material surface. This effectively solves the problem of traditional teaching methods where angle adjustment relies on manual experience and is difficult to control precisely. By controlling the parallelism between the electrode cap and the welding material surface, welding spatter, reduced joint strength, and crack defects caused by weld point misalignment can be effectively avoided. This invention improves the mechanical properties and appearance quality of welded joints, making it particularly suitable for applications such as automotive body welding where high welding quality is required. Through non-contact laser measurement and spot guidance, it achieves "one-time positioning and one-time leveling," significantly reducing the need for repeated pressing and welding tests during traditional trial welding and debugging processes, saving debugging time and material costs, and improving production efficiency. The device only requires the addition of laser displacement and laser positioning sensors to existing C-shaped spot welding clamps, without the need for complex mechanical structures or significant modifications to existing equipment. It is easily integrated into industrial robot systems, offers strong visualization of the operation process, and lowers the technical threshold and labor intensity for operators. This invention is not only applicable to… The C-shaped spot welding clamp's principle can also be extended to the positioning and attitude control of other types of welding clamps. By adjusting the sensor layout and number, it can adapt to different welding scenarios and workpiece shapes, possessing good engineering applicability and technical extensibility. Multiple laser displacement sensors arranged around the movable side electrode rod can simultaneously measure distances at multiple azimuth angles between the electrode cap axis and the welding surface, thus comprehensively and in real-time reflecting the parallelism deviation between the electrode cap end face and the welding material surface. By comparing the consistency of the distance values ​​measured by each laser displacement sensor, it is possible to more accurately determine whether the electrode cap is parallel to the welding surface. If the values ​​are inconsistent, then... This indicates a tilt, allowing operators or the control system to make precise attitude corrections and avoid errors that may arise from single-point measurements. The laser displacement sensor is arranged circumferentially along the movable side electrode rod, which does not affect the normal movement and welding function of the electrode cap, while enabling multi-angle detection and facilitating integration into existing C-shaped welding clamp structures. By presetting the angle between the sensor laser beam and the electrode cap axis, the system can flexibly adapt to different welding angles or workpiece shapes, enhancing its adaptability and practicality. Each sensor maintains a parallel or identical angle relationship with the electrode cap axis, facilitating the unified setting of measurement benchmarks during the calibration stage, making subsequent distance comparisons and attitude judgments more intuitive and convenient.

Claims

1. A C-shaped spot welding clamp teaching and positioning method, characterized in that, include: S1, Calibration: The reference plate is placed between the fixed side electrode cap and the movable side electrode cap of the spot welding clamp and clamped. The measurement values ​​of each laser displacement sensor to the surface of the reference plate are obtained, and the measurement values ​​are set as the zero point of each laser displacement sensor. S2, Location Positioning: Move the spot welding clamp so that the laser spot formed by the laser positioning sensor on the surface of the material to be welded is located at the target welding position; S3, Angle Adjustment: Centered on the target welding position, adjust the posture of the spot welding clamp until the measurement values ​​displayed by each laser displacement sensor are consistent. At this time, the end face of the movable side electrode cap is parallel to the surface of the material to be welded. S4, Demonstration: Adjust the position of the spot welding clamp so that the laser positioning sensor spot is aligned with the target welding position; S5, Data Recording: Record the position and orientation data of the spot welding clamp at this time as teaching data for the target welding point.

2. The C-shaped spot welding clamp teaching and positioning method according to claim 1, characterized in that, In S1, each laser displacement sensor is adjusted so that the emitted laser beam is parallel to the axis of the movable side electrode cap.

3. The C-shaped spot welding clamp teaching and positioning method according to claim 1, characterized in that, The reference plate is a flat steel plate.

4. A C-shaped spot welding clamp teaching and positioning device using the method described in any one of claims 1-3, characterized in that, The system includes a spot welding clamp, a laser displacement sensor, and a laser positioning sensor. The spot welding clamp includes a fixed-side electrode cap, a movable-side electrode cap, and a movable-side electrode rod. The fixed-side electrode cap is fixed on the fixed-side clamp arm of the spot welding clamp, and the movable-side electrode cap is installed at one end of the movable-side electrode rod. There are multiple laser displacement sensors, which are fixedly arranged around the movable-side electrode rod. The direction of the laser beam emitted by the sensors is parallel to or has the same preset angle as the axis of the movable-side electrode cap. A laser positioning sensor is mounted on the spot welding clamp to form a light spot on the surface of the material to be welded, indicating the welding position.

5. The C-shaped spot welding clamp teaching and positioning device according to claim 4, characterized in that, The spot welding pliers mentioned are C-shaped spot welding pliers.

6. The C-shaped spot welding clamp teaching and positioning device according to claim 4, characterized in that, The laser positioning sensor and the laser displacement sensor emit lasers of different colors.

7. The C-shaped spot welding clamp teaching and positioning device according to claim 4, characterized in that, The laser positioning sensor forms a circular, annular, or cross-shaped light spot on the surface of the material to be welded.

8. The C-shaped spot welding clamp teaching and positioning device according to claim 4, characterized in that, The number of laser displacement sensors is ≥3.

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