Automatic focus measuring welding device

Abstract

This utility model discloses an automatic focal length measuring welding device, belonging to the field of welding technology. It includes a coaxial focal length measuring module, a laser welding module, a dynamic compensation mechanism, and a control module. The coaxial focal length measuring module emits a detection laser onto the surface of the workpiece before welding and receives the reflected light from the workpiece surface to obtain the offset between the actual position of the workpiece surface in the optical axis direction and the calibrated focal point position. The laser welding module emits a welding laser onto the workpiece surface. The dynamic compensation mechanism is connected to both the laser welding module and the coaxial focal length measuring module, and drives the laser welding module to move closer to or further away from the workpiece surface in the optical axis direction. The control module is connected to both the coaxial focal length measuring module and the dynamic compensation mechanism, and adjusts the position of the laser welding module relative to the workpiece surface according to the offset. This utility model achieves the technical effect of improving welding quality, increasing product yield, and enhancing reliability.

Description

Technical Field

[0001] This utility model belongs to the field of welding technology, and specifically relates to an automatic focal length measuring welding device. Background Technology

[0002] Laser welding technology is widely used in nanosecond spot welding processes for 3C electronic products such as smartphones and tablets. The quality of laser welding mainly depends on the precise control of the laser focal length. The accuracy of the focal length directly determines the welding strength, the weld joint strength, and the yield of the final product. In existing technologies, a fixed focal length welding method is usually used. A fixed focal length value is preset before welding, and the welding operation is performed by installing this fixed focal length value on the laser machine. However, in actual production, due to large fluctuations in the reference dimensions of materials, such as rework materials after CNC milling of weld joints and steel sheets, the welding residue effect of each piece of material is inconsistent, resulting in different milling degrees for each piece of material. This leads to differences in the surface height of the welded steel sheets. Fixing the laser focus at a certain set height cannot adapt to the actual surface height variations of different materials. Deviations in the laser focal length will result in insufficient welding strength, failing to meet the stringent requirements for structural strength, and seriously affecting product yield and reliability.

[0003] Therefore, it is necessary to provide a new technical solution to solve the above-mentioned technical problems. Utility Model Content

[0004] The technical problem to be solved by this utility model is the problem of poor welding quality, low product yield and reliability.

[0005] To address the aforementioned technical problems, this utility model provides an automatic focal length measurement welding device. The device includes a coaxial focal length measurement module, a laser welding module, a dynamic compensation mechanism, and a control module. The coaxial focal length measurement module emits a detection laser onto the surface of the workpiece before welding and receives the reflected light from the workpiece surface to obtain the offset between the actual position of the workpiece surface in the optical axis direction and the calibrated focal point position. The laser welding module shares the same optical axis with the coaxial focal length measurement module and emits a welding laser onto the surface of the workpiece. The dynamic compensation mechanism is connected to both the laser welding module and the coaxial focal length measurement module, and drives the laser welding module to move closer to or further away from the workpiece surface in the optical axis direction. The control module is communicatively connected to both the coaxial focal length measurement module and the dynamic compensation mechanism, and receives the offset and adjusts the position of the laser welding module relative to the workpiece surface based on the offset.

[0006] Optionally, the laser welding module includes a pulsed laser source and a galvanometer unit coaxially arranged with the pulsed laser source. The galvanometer unit is disposed between the pulsed laser source and the workpiece, and is used to guide the welding laser emitted by the pulsed laser source and transmitted through the optical path transmission component to the surface of the workpiece.

[0007] Optionally, the control module includes at least a judgment unit and a compensation unit. The judgment unit is used to determine whether the offset is within the preset threshold range based on the offset and the preset threshold range. The compensation unit is used to generate a compensation signal based on the offset when the offset is within the preset threshold range, so as to drive the laser welding module to move in the optical axis direction to compensate for the offset, so that the focus of the welding laser falls on the surface of the workpiece.

[0008] Optionally, the control module further includes an alarm unit, which is used to issue an alarm signal and stop welding when the offset exceeds a preset threshold range.

[0009] Optionally, the dynamic compensation mechanism includes a first displacement component, a second displacement component connected to the first displacement component, a third displacement component connected to the second displacement component, and a support frame. The first displacement component drives the second displacement component to move along the X-axis; the second displacement component drives the third displacement component to move along the Y-axis; the laser welding module and the coaxial focal length measurement module are respectively connected to the support frame, and the support frame is connected to the third displacement component. The third displacement component drives the support frame to move along the Z-axis, and the optical axis direction is parallel to the Z-axis direction; wherein the control module is respectively connected to the first displacement component, the second displacement component, and the third displacement component.

[0010] Optionally, the automatic focal length measuring welding device further includes a frame with a table, on which the dynamic compensation mechanism is mounted, and the frame provides support for the dynamic compensation mechanism.

[0011] Optionally, the automatic focal length measuring welding device further includes a positioning fixture mounted on the table, the positioning fixture being used to support the workpiece.

[0012] Optionally, the automatic focal length measuring welding device further includes a monitor camera, which is mounted on the dynamic compensation mechanism and is used to observe the surface of the workpiece in real time.

[0013] Optionally, the coaxial focal length measurement module includes a coaxial focal length measuring instrument, wherein the detection optical path of the coaxial focal length measuring instrument is coaxial with the welding optical path of the laser welding module.

[0014] Optionally, the laser welding module includes a nanosecond spot welding laser source for emitting nanosecond pulse welding lasers.

[0015] Beneficial effects:

[0016] This invention provides an automatic focal length measuring welding device. A coaxial focal length measuring module emits a detection laser towards the surface of the workpiece before welding and receives the reflected light from the workpiece surface to obtain the offset between the actual position of the workpiece surface in the optical axis direction and the calibrated focal point position. The laser welding module and the coaxial focal length measuring module share the same optical axis. The laser welding module emits a welding laser towards the workpiece surface. A dynamic compensation mechanism is connected to both the laser welding module and the coaxial focal length measuring module, driving the laser welding module to move closer to or further away from the workpiece surface in the optical axis direction. A control module is communicatively connected to both the coaxial focal length measuring module and the dynamic compensation mechanism, receiving the offset and adjusting the position of the laser welding module relative to the workpiece surface based on the offset. In this way, when laser welding is required on a workpiece, the coaxial focal length measurement module measures the offset between the actual position of the workpiece surface and the calibrated focal point before welding. Based on this offset, the control module drives the dynamic compensation mechanism to move along the optical axis until the laser focal point of the welding laser coincides with the workpiece surface. Because the laser welding module and the coaxial focal length measurement module are coaxial, the focal position of the welding laser is corrected to the calibration point, avoiding mechanical movement errors and obstruction effects. The welding laser can always be focused on the welding area of ​​the workpiece surface, overcoming defocusing caused by workpiece dimensional fluctuations, surface unevenness, or positional deviations. Subsequently, during laser welding, the welding energy is accurately focused on the welding area of ​​the workpiece surface, which helps improve welding quality, product yield, and reliability. This achieves the technical effect of improving welding quality, product yield, and reliability. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of an automatic focal length measuring welding device provided in an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the coaxial focal length measurement module and galvanometer unit in an automatic focal length measurement welding device provided for an embodiment of this utility model.

[0020] Figure 3 This is a schematic diagram of the structure of the platform in an automatic focal length measuring welding device provided for an embodiment of the present utility model.

[0021] Figure 4 This is a structural block diagram of the control module in an automatic focal length measuring welding device provided for an embodiment of the present utility model.

[0022] Figure 5 This is a structural block diagram of a coaxial focal length measurement module, a control module, and a dynamic compensation mechanism in an automatic focal length measurement welding device provided for an embodiment of this utility model.

[0023] The meanings of the labels in the attached diagram are as follows: 1—Coaxial focal length measurement module, 2—Laser welding module, 21—Pulsed laser source, 22—Galvanometer unit, 23—Optical path transmission component, 3—Dynamic compensation mechanism, 31—First displacement component, 32—Second displacement component, 33—Third displacement component, 34—Bearing frame, 4—Control module, 41—Judgment unit, 42—Compensation unit, 43—Alarm unit, 5—Frame, 51—Tabletop, 6—Monitor camera. Detailed Implementation

[0024] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0025] To enable those skilled in the art to better understand the solutions of this application, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0026] In the embodiments of this application, "at least one" refers to one or more; "multiple" refers to two or more. In the description of this application, the terms "first," "second," "third," etc., are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance, nor should they be construed as indicating or implying order.

[0027] In this specification, references such as "one embodiment" or "some embodiments" mean that one or more embodiments of this application include the specific features, structures, or characteristics described in connection with that embodiment. Therefore, the terms "comprising," "including," "having," and variations thereof in this specification all mean "including but not limited to," unless otherwise specifically emphasized. It should be noted that in the embodiments of this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone.

[0028] It should be noted that, in the embodiments of this utility model, when a component is referred to as being "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. When a component is considered to be "set on" another component, it can be directly set on the other component or there may be an intervening component. Furthermore, in the embodiments of this application, "connection" can also be understood as an electrical connection; the connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components. The terms "vertical," "horizontal," "left," "right," and similar expressions used in the embodiments of this utility model are for illustrative purposes only and are not intended to limit the utility model.

[0029] This utility model provides an automatic focal length measuring welding device. Please refer to [link to relevant documentation]. Figures 1 to 5 As shown, Figure 1 This is a schematic diagram of the structure of an automatic focal length measuring welding device provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the coaxial focal length measurement module and galvanometer unit in an automatic focal length measurement welding device provided by an embodiment of this utility model. Figure 3 This is a schematic diagram of the structure of the platform in an automatic focal length measuring welding device provided in an embodiment of the present invention. Figure 4 This is a structural block diagram of the control module in an automatic focal length measuring welding device provided in an embodiment of this utility model. Figure 5This is a structural block diagram of a coaxial focal length measurement module, a control module, and a dynamic compensation mechanism in an automatic focal length measurement welding device provided by an embodiment of this utility model. The automatic focal length measurement welding device provided by this utility model includes a coaxial focal length measurement module 1, a laser welding module 2, a dynamic compensation mechanism 3, and a control module 4. The coaxial focal length measurement module 1 is used to emit a detection laser onto the surface of the workpiece before welding and to receive the reflected light from the surface of the workpiece to determine the offset between the actual position of the workpiece surface in the optical axis direction and the calibrated focal point position. The laser welding module 2 shares the same optical axis with the coaxial focal length measurement module 1 and is used to emit a welding laser onto the surface of the workpiece. The dynamic compensation mechanism 3 is connected to both the laser welding module 2 and the coaxial focal length measurement module 1, and is used to drive the laser welding module 2 to move closer to or further away from the surface of the workpiece in the optical axis direction. The control module 4 is communicatively connected to both the coaxial focal length measurement module 1 and the dynamic compensation mechanism 3, and is used to receive the offset and adjust the position of the laser welding module 2 relative to the surface of the workpiece according to the offset.

[0030] Before welding, a detection laser can be emitted onto the surface of the workpiece by the coaxial focal length measurement module 1, and the reflected light from the surface of the workpiece can be received. The offset between the actual position of the workpiece surface in the optical axis direction and the calibrated focal point position can be determined based on the intensity or waveform of the reflected light. Alternatively, the coaxial focal length measurement module 1 can project the detection laser onto the surface of the workpiece to form a monitoring spot, and the reflected light can be transmitted in reverse through the same optical path. For example, the axial deviation between the actual position of the surface and the calibrated focal point can be calculated with a certain resolution by analyzing the pixel offset of the spot center on the imaging surface.

[0031] Since the laser welding module 2 and the coaxial focal length measurement module 1 share the same optical axis, the detection point of the coaxial focal length measurement module 1 and the welding point of the laser welding module 2 will be located at the same position. This eliminates the need to move the welding head of the laser welding module 2 or the position of the workpiece in the horizontal plane during the welding process. The workpiece can refer to a mobile phone frame using nanosecond spot welding.

[0032] The laser welding module 2 outputs a beam that can form a welding spot on the surface of the workpiece. The dynamic compensation mechanism 3 drives the laser welding module 2 to move closer to or further away from the surface of the workpiece in the optical axis direction, thereby adjusting the distance between the laser welding module 2 and the surface of the workpiece.

[0033] In this embodiment, a detection laser is emitted towards the surface of the workpiece before welding by a coaxial focal length measurement module 1, and the reflected light is received by the coaxial focal length measurement module 1 to obtain the offset between the actual position of the workpiece surface in the optical axis direction and the calibrated focal point position. The laser welding module 2 and the coaxial focal length measurement module 1 share the same optical axis. The laser welding module 2 emits a welding laser towards the surface of the workpiece. The dynamic compensation mechanism 3 is connected to both the laser welding module 2 and the coaxial focal length measurement module 1. The dynamic compensation mechanism 3 drives the laser welding module 2 to move closer to or further away from the surface of the workpiece in the optical axis direction. The control module 4 is communicatively connected to both the coaxial focal length measurement module 1 and the dynamic compensation mechanism 3. The control module 4 receives the offset and adjusts the position of the laser welding module 2 relative to the surface of the workpiece according to the offset. In this way, when laser welding is required on a workpiece, the coaxial focal length measurement module 1 measures the offset between the actual position of the workpiece surface and the calibrated focal point before welding. Based on this offset, the control module 4 drives the dynamic compensation mechanism 3 to move along the optical axis until the laser focal point of the welding laser coincides with the surface of the workpiece. Because the laser welding module 2 and the coaxial focal length measurement module 1 are coaxial, the focal position of the welding laser is corrected to the calibration point, avoiding mechanical movement errors and obstruction effects. The welding laser can always be focused on the welding area of ​​the workpiece surface, overcoming defocusing caused by workpiece dimensional fluctuations, surface unevenness, or positional deviations. Subsequently, during the laser welding process, the welding energy is accurately focused on the welding area of ​​the workpiece surface, which helps improve welding quality, product yield, and reliability. This achieves the technical effect of improving welding quality, product yield, and reliability.

[0034] As one embodiment, the laser welding module 2 in the automatic focal length measuring welding device provided by this utility model includes a pulsed laser source 21 and a galvanometer unit 22. The galvanometer unit 22 is coaxially arranged with the pulsed laser source 21 and is positioned between the pulsed laser source 21 and the workpiece. The galvanometer unit 22 is used to guide the welding laser emitted by the pulsed laser source 21 and transmitted through the optical path transmission component 23 to the surface of the workpiece. The pulsed laser source 21 may include a nanosecond pulsed laser, and the galvanometer unit 22 may include a dual-axis scanning galvanometer. The galvanometer unit 22 is positioned between the pulsed laser source 21 and the workpiece. The welding laser emitted by the pulsed laser source 21 is transmitted through the optical path transmission component 23, such as an optical fiber, and then guided by the galvanometer unit 22 to a specific welding point on the surface of the workpiece. In addition, the galvanometer unit 22 can also control the angle of the reflector through a servo motor to quickly scan the welding laser to the target position on the surface of the workpiece, so that the laser focal position can be adjusted in real time to match the offset measured by the coaxial focal length measuring module 1.

[0035] In some embodiments, the control module 4 of the automatic focal length measuring welding device provided by this utility model includes at least a judgment unit 41 and a compensation unit 42. The judgment unit 41 is used to determine whether the offset is within the preset threshold range based on the offset and the preset threshold range. The compensation unit 42 is used to generate a compensation signal based on the offset when the offset is within the preset threshold range, so as to drive the laser welding module 2 to move in the optical axis direction to compensate for the offset, so that the focus of the welding laser falls on the surface of the workpiece. The judgment unit 41 may include an embedded microprocessor, and the compensation unit 42 may include a digital signal processor. In actual operation, the control module 4 can perform a zero-return action on the dynamic compensation mechanism 3 to complete the origin calibration of the X-axis, Y-axis and Z-axis, and then place the workpiece to be welded into the positioning fixture, such as selecting three open areas on the surface of the workpiece as measurement points to represent the surface of the entire workpiece. The control module 4 moves the coaxial focal length measuring instrument sequentially above the above three measurement points through the dynamic compensation mechanism 3. The coaxial focus measuring instrument collects the backlight intensity and waveform in real time. The judgment unit 41 performs frame filtering on the three sampling results, such as removing the maximum and minimum values ​​and taking the average to obtain the offset ΔZ at that point. After all the data is collected, the compensation unit 42 can calculate the average offset ΔZ1 and compare the average offset ΔZ1 with a preset threshold. If –0.2mm≤ΔZ1≤+0.2mm, welding can be performed directly; if –1.0mm≤ΔZ1<–0.2mm, or +0.2mm<ΔZ1≤+1.0mm, welding is performed after compensation; if ΔZ1<–1.0mm, or ΔZ1>+1.0mm, the alarm unit 43 will issue an audible and visual alarm and stop the machine, transferring the case to manual handling. During dynamic focus compensation, the compensation unit 42 can output a compensation signal ΔZ1. The dynamic compensation mechanism 3 will drive the support frame 34 to move a distance ΔZ1 along the Z-axis, ensuring that the focus of the pulsed laser source 21 accurately falls on the surface of the steel sheet. After positioning, the monitor camera 6 can take a real-time picture to confirm that the focus is aligned, either manually or through image algorithms. During welding, the control module 4 can trigger the pulsed laser source 21 to emit a pulsed welding laser. The galvanometer unit 22 will complete the welding according to a preset trajectory. Furthermore, the monitor camera 6 can continuously monitor the welding process, and if a weld deviation is detected, manual emergency stop is possible. This ensures that the focus correction process only targets controllable offsets, avoiding ineffective adjustments and achieving overlap between the welding laser focus and the workpiece surface.

[0036] In some embodiments, the control module 4 of the automatic focal length measuring welding device provided in this utility model further includes an alarm unit 43. The alarm unit 43 is used to issue an alarm signal and stop welding when the offset exceeds a preset threshold range. The alarm unit 43 is such as an audible and visual alarm. When the judgment unit 41 determines that the offset exceeds the preset threshold range, the alarm unit 43 triggers an alarm signal, such as a buzzer or flashing light, and simultaneously sends a stop command to stop the welding process, preventing defocus welding caused by the inability to correct the focus, thereby avoiding welding energy dispersion or weld penetration defects.

[0037] In some embodiments, the dynamic compensation mechanism 3 in an automatic focal length measuring welding device provided by this utility model includes a first displacement component 31, a second displacement component 32, a third displacement component 33, and a support frame 34. The second displacement component 32 is connected to the first displacement component 31, and the first displacement component 31 drives the second displacement component 32 to move along the X-axis. The third displacement component 33 is connected to the second displacement component 32, and the second displacement component 32 drives the third displacement component 33 to move along the Y-axis. The laser welding module 2 and the coaxial focal length measuring module 1 are respectively connected to the support frame 34, and the support frame 34 is connected to the third displacement component 33. The third displacement component 33 drives the support frame 34 to move along the Z-axis. The optical axis direction is parallel to the Z-axis direction. The control module 4 is connected to the first displacement component 31, the second displacement component 32, and the third displacement component 33. The first displacement component 31 may include a servo linear slide, or the second displacement component 32 may include a ball screw slide, or the third displacement component 33 may include a piezoelectric ceramic actuator. The first displacement component 31 drives the second displacement component 32 to move along the X-axis for horizontal adjustment, the second displacement component 32 drives the third displacement component 33 to move along the Y-axis for longitudinal adjustment, and the third displacement component 33 drives the support frame 34 to move along the Z-axis. By using the dynamic compensation mechanism 3 and the support frame 34 to move the laser welding module 2, the surface position deviation of the workpiece can be compensated, so that the dynamic compensation is performed along the optical axis to overcome the three-dimensional displacement caused by workpiece placement or surface unevenness.

[0038] In some embodiments, the automatic focal length measuring welding device provided by this utility model further includes a frame 5, on which a table 51, such as a horizontal worktable, is mounted. A dynamic compensation mechanism 3 is mounted on the table 51, and the frame 5 provides support for the dynamic compensation mechanism 3. The frame 5, as a fixed foundation, can absorb external vibrations and maintain the table 51 horizontally, preventing the dynamic compensation mechanism 3 from swaying during movement or compensation. This results in more precise movement of the optical axis and ensures that the collinearity of coaxial focal length measurement and welding laser emission is not disturbed by external factors, which is beneficial for accurately focusing welding energy onto the welding area.

[0039] In some embodiments, the automatic focal length measuring welding device provided by this utility model further includes a positioning fixture, such as a vacuum adsorption fixture. The positioning fixture is mounted on the table 51 and is used to support the workpiece, preventing the workpiece from shifting during the welding process. That is, by fixing the position of the workpiece on the table 51 with a mechanical fixture, vibration or deviation of the workpiece during measurement or welding is reduced, improving the consistency of the workpiece's surface position, making the offset obtained by the coaxial focal length measuring module 1 more accurate, and avoiding measurement errors caused by workpiece position deviation.

[0040] In some embodiments, the automatic focal length measuring welding device provided by this utility model further includes a monitor camera 6, such as an industrial CCD camera, for real-time observation of image data of the workpiece surface. The monitor camera 6 is mounted on the dynamic compensation mechanism 3 and is used to observe the workpiece surface in real time. The monitor camera 6 provides visual information about the workpiece surface through real-time imaging, assisting the coaxial focal length measuring module 1 in detecting surface unevenness or local defects. It can also be displayed on an external screen to provide operators with real-time visual information about the workpiece surface.

[0041] In some embodiments, the coaxial focal length measuring module 1 in the automatic focal length measuring welding device provided by this utility model includes a coaxial focal length measuring instrument. The detection optical path of the coaxial focal length measuring instrument is coaxial with the welding optical path of the laser welding module 2, so that the detection laser and the welding laser share the same optical path to eliminate parallax or mechanical interference. It outputs the precise offset between the actual position of the workpiece surface and the calibrated focal point. Based on this, the control module 4 can directly adjust the dynamic compensation mechanism 3 to move along the optical axis, so that the focal correction process is efficient and accurate, and the welding laser is always focused on the welding area, overcoming the fluctuation of the workpiece reference size or the surface unevenness.

[0042] In some embodiments, the laser welding module 2 in the automatic focal length measuring welding device provided by this utility model includes a nanosecond spot welding laser source. This nanosecond spot welding laser source emits nanosecond pulse welding lasers to provide high-energy pulse welding. The nanosecond spot welding laser source generates short-pulse high-energy lasers, which, after focus correction, can precisely spot weld on the surface of the workpiece. The control module 4, combined with offset compensation, activates the nanosecond pulses, concentrating the welding energy at the focal position, which is beneficial for improving welding quality. By reducing the heat-affected zone and avoiding heat diffusion caused by defocusing, the welding energy is precisely applied, overcoming welding defects caused by surface position deviations of the workpiece, thus improving welding quality and product yield.

[0043] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0044] The above embodiments only illustrate preferred implementations of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. An automatic focus measuring welding device characterized by comprising: The automatic focal length measurement welding device includes a coaxial focal length measurement module, a laser welding module, a dynamic compensation mechanism, and a control module. The coaxial focal length measurement module emits a detection laser onto the surface of the workpiece before welding and receives the reflected light from the workpiece surface to obtain the offset between the actual position of the workpiece surface in the optical axis direction and the calibrated focal point position. The laser welding module shares the same optical axis with the coaxial focal length measurement module and emits a welding laser onto the surface of the workpiece. The dynamic compensation mechanism is connected to both the laser welding module and the coaxial focal length measurement module, and drives the laser welding module to move closer to or further away from the workpiece surface in the optical axis direction. The control module is communicatively connected to both the coaxial focal length measurement module and the dynamic compensation mechanism, and receives the offset and adjusts the position of the laser welding module relative to the workpiece surface based on the offset.

2. The automatic focus measuring welding apparatus according to claim 1, wherein The laser welding module includes a pulsed laser source and a galvanometer unit coaxially arranged with the pulsed laser source. The galvanometer unit is disposed between the pulsed laser source and the workpiece. The galvanometer unit is used to guide the welding laser emitted by the pulsed laser source and transmitted through the optical path transmission component to the surface of the workpiece.

3. The automatic focus measuring welding apparatus according to claim 1, wherein The control module includes at least a judgment unit and a compensation unit. The judgment unit is used to determine whether the offset is within the preset threshold range based on the offset and the preset threshold range. The compensation unit is used to generate a compensation signal based on the offset when the offset is within the preset threshold range, so as to drive the laser welding module to move in the optical axis direction to compensate for the offset, so that the focus of the welding laser falls on the surface of the workpiece.

4. The automatic focus measuring welding apparatus according to claim 3, wherein The control module also includes an alarm unit, which is used to issue an alarm signal and stop welding when the offset exceeds a preset threshold range.

5. The automatic focus measuring welding apparatus according to claim 1, wherein The dynamic compensation mechanism includes a first displacement component, a second displacement component connected to the first displacement component, a third displacement component connected to the second displacement component, and a support frame. The first displacement component drives the second displacement component to move along the X-axis; the second displacement component drives the third displacement component to move along the Y-axis; the laser welding module and the coaxial focal length measurement module are respectively connected to the support frame, and the support frame is connected to the third displacement component. The third displacement component drives the support frame to move along the Z-axis, and the optical axis is parallel to the Z-axis; wherein the control module is respectively connected to the first displacement component, the second displacement component, and the third displacement component.

6. The automatic focus measuring welding apparatus according to claim 1, wherein The automatic focal length measuring welding device also includes a frame with a table, on which the dynamic compensation mechanism is mounted, and the frame provides support for the dynamic compensation mechanism.

7. The automatic focal length measuring welding device according to claim 6, characterized in that, The automatic focal length measuring welding device also includes a positioning fixture mounted on the table, which is used to support the workpiece.

8. The automatic focus measuring welding apparatus according to claim 1, wherein The automatic focal length measuring welding device also includes a monitor camera, which is mounted on the dynamic compensation mechanism and is used to observe the surface of the workpiece in real time.

9. The automatic focus measuring welding apparatus as set forth in claim 1, wherein The coaxial focal length measurement module includes a coaxial focal length measuring instrument, and the detection optical path of the coaxial focal length measuring instrument is coaxial with the welding optical path of the laser welding module.

10. The automatic focus measuring welding apparatus as set forth in claim 1, wherein The laser welding module includes a nanosecond spot welding laser source for emitting nanosecond pulse welding lasers.

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