Welding path generation method for laser welding device

Abstract

A method for generating a welding path for a laser welding device includes the following steps: drawing a computer drawing of a welding outline using computer-aided design software; establishing a coordinate system in the computer drawing; selecting a starting welding point and several calibration welding points in the computer drawing; calculating the length and calibration angle of the welding calibration line for each calibration welding point using the computer-aided design software; calculating the coordinates of each calibration welding point during welding using the coordinates of the rotation axis and the starting welding point, as well as the length of the welding calibration line for each calibration welding point; and importing the length of the welding calibration line and the coordinates of each calibration welding point during welding into an electronic cam system used to control the movement of a rotating part and a welding head to generate a welding path. This welding path generation method maintains a constant distance between the welding head and the welding point, allowing the welding head to pass through the welding points at a constant speed, improving welding quality and saving time and effort when changing weld parts.

Description

Technical Field

[0001] The present invention relates to a welding path generation method, in particular to a welding path generation method for a welding head of a laser welding device. Background Art

[0002] Existing laser welding devices include a rotating member and a welding head. The rotating member is used to fix the weldment and rotates about a rotation axis. The welding head is arranged along a first direction perpendicular to the rotation axis and faces the weldment fixed to the rotating member. The welding head can move relative to the rotating member in the first direction and a second direction, the second direction being perpendicular to the rotation axis and the first direction. The welding path of the welding head is generated using a teaching method. In this teaching method, the distance between the welding head and the weld point cannot be maintained constant, the speed of the welding head passing through the weld point is uneven, and when the weldment is changed, a lot of teaching and point correction work is required, which is time-consuming and labor-intensive. Summary of the Invention

[0003] The purpose of the present invention is to provide a welding path generation method for a laser welding device, in which the distance between the welding head and the welding point is kept constant, the welding head passes through the welding point at a constant speed, the welding quality is improved, and time and labor are saved when changing the weldment.

[0004] The present invention provides a method for generating a welding path of a laser welding device, comprising the following steps:

[0005] Based on the dimensions of the weld contour, a computer drawing of the weld contour line is drawn using computer-aided design software;

[0006] A coordinate system corresponding to the laser welding device is established in a computer drawing, wherein the longitudinal axis Yc of the coordinate system is parallel to the first direction, and the transverse axis Xc of the coordinate system is parallel to the second direction;

[0007] Select a starting welding point and several calibration welding points on the weldment outline in the computer drawing, and set the rotation axis and the starting welding point to the set coordinates respectively;

[0008] Connect the rotation axis and the starting welding point to form a welding starting line, connect the rotation axis and each calibration welding point to form a welding calibration line, and record the angle required for each welding calibration line to rotate around the rotation axis in the same circumferential direction until it coincides with the welding starting line as the calibration angle. Use computer-aided design software to calculate the length and calibration angle of the welding calibration line of each calibration welding point;

[0009] Calculate the coordinates of each calibration welding point during welding using the coordinates of the rotation axis and the starting welding point and the length of the welding calibration line of each calibration welding point;

[0010] The length of the welding calibration line of each calibration welding point and the coordinates during welding are imported into the electronic cam system used to control the movement of the rotating part and the welding head. The electronic cam system is used to generate a welding path that enables the welding head to pass through the welding contour of the welded part at a uniform speed.

[0011] The welding path generation method of the laser welding device provided by the present invention obtains the welding path by calculation, and sets the corresponding rotation speed for the rotating part in the electronic cam system according to the change of the welding path. Compared with the welding path generated by the teaching method, the welding path generated by the welding path generation method provided by the present invention maintains a constant distance between the welding head and the welding point, and the welding head passes through the welding point at a constant speed, thereby improving the welding quality and saving time and effort when changing the welded part.

[0012] In an exemplary embodiment of the welding path generation method, the step of calculating the coordinates of each calibration welding point during welding using the coordinates of the rotation axis and the starting welding point and the length of the welding calibration line of each calibration welding point includes:

[0013] The length of the welding starting line is calculated using the coordinates of the rotation axis and the starting welding point;

[0014] The angle between the welding starting line and the horizontal axis Xc is calculated using the coordinates of the rotation axis and the starting welding point, and recorded as the initial angle;

[0015] The change in the coordinates of the starting welding point to the coordinates of each calibration welding point on the horizontal axis Xc and the vertical axis Yc is calculated using the length of the welding starting line, the initial angle and the length of the welding calibration line of each calibration welding point;

[0016] The coordinates of each calibration welding point during welding are calculated using the coordinates of the starting welding point and the changes from the coordinates of the starting welding point to the coordinates of each calibration welding point on the horizontal axis Xc and the vertical axis Yc.

[0017] In an exemplary embodiment of the welding path generation method, the change in the coordinates of the starting welding point to the coordinates of each calibration welding point on the horizontal axis Xc and the vertical axis Yc is calculated using the following formula:

[0018] ΔX=(R0-Rn)cosθ;

[0019] ΔY=(R0-Rn)sinθ;

[0020] Where R0 represents the length of the welding start line, Rn represents the length of the welding calibration line, θ represents the initial angle, ΔX represents the change in coordinates from the starting welding point to the calibration welding point on the horizontal axis Xc, and ΔY represents the change in coordinates from the starting welding point to the calibration welding point on the horizontal axis Yc.

[0021] In an exemplary embodiment of a welding path generation method, the steps include: importing the length of the welding calibration line of each calibration welding point and the coordinates during welding into an electronic cam system for controlling the movement of a rotating member and a welding head, and using the electronic cam system to generate a welding path that enables the welding head to pass through the welding contour of the welded part at a uniform speed, including:

[0022] Import the length of the welding calibration line of each calibration welding point and the coordinates during welding into the electronic CAM system;

[0023] The electronic cam system calculates the rotation speed ratio of the rotating part when the welding head passes through each calibration welding point at a uniform speed according to the length of the welding calibration line of each calibration welding point;

[0024] The electronic cam system creates a virtual spindle and generates a cam table based on the speed ratio of the rotating part when the welding head passes through each calibrated welding point at a uniform speed.

[0025] In an exemplary embodiment of the welding path generation method, the rotational speed ratio of the rotating part when the welding head passes through each calibration welding point at a uniform speed is calculated using the following formula:

[0026] V=W*Rn;

[0027] Wherein, V represents the linear velocity of the welding head when passing through each calibration welding point, Rn represents the length of the welding calibration line, and W represents the rotation speed of the rotating part.

[0028] In an exemplary embodiment of the welding path generation method, the welding path generation method further includes: using a machine vision system to photograph the welding part fixed to the rotating part, and performing offset correction on the generated cam table according to the position of the starting welding point in the machine vision system.

[0029] In an exemplary embodiment of the welding path generation method, the welding path generation method further includes: after calculating the length of the welding calibration line of each calibration welding point, the calibration welding points whose difference between the length of the welding calibration line and the welding start line is less than a preset range are eliminated and are not used for the calculation of subsequent steps.

[0030] In an illustrative embodiment of the welding path generation method, in the step of calculating the coordinates of each calibrated welding point during welding using the coordinates of the rotation axis and the starting welding point and the length of the welding calibration line of each calibrated welding point, the coordinates of the rotation axis and the starting welding point and the length of the welding calibration line of each calibrated welding point are imported into a programmable logic controller of the electronic cam system, and the coordinates of each calibrated welding point during welding are calculated using the programmable logic controller.

[0031] In an exemplary embodiment of the welding path generation method, the rotation axis is set to the origin of the coordinate system.

[0032] In an illustrative embodiment of the welding path generation method, in the step: a starting welding point and several calibration welding points are selected on the weldment contour line in the computer drawing, the rotation axis and the starting welding point are moved to known coordinates respectively, and the angles between the welding calibration lines of each two adjacent calibration welding points are equal. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The following drawings are only used to schematically illustrate and explain the present invention and are not intended to limit the scope of the present invention.

[0034] Figure 1 The figure is a flowchart of an exemplary embodiment of a method for generating a welding path based on a laser welding device.

[0035] Figure 2 This is a schematic diagram of the implementation principle of the welding path generation method based on a laser welding device.

[0036] Figure 3 This is another implementation principle diagram of a welding path generation method based on a laser welding device.

[0037] Figure 4 This is a partial flow chart of a welding path generation method based on a laser welding device.

[0038] Figure 5 A partial flow chart of a welding path generation method based on a laser welding device.

[0039] Figure 6 The figure is a flowchart of another exemplary embodiment of a method for generating a welding path based on a laser welding device.

[0040] Label Description

[0041] 10 welding heads

[0042] S welding contour line

[0043] 0Rotation axis

[0044] S0 starting welding point

[0045] Sn calibration welding point

[0046] R0 welding starting line

[0047] Rn welding calibration line

[0048] θ initial angle

[0049] θn calibration angle

[0050] Y first direction

[0051] X second direction DETAILED DESCRIPTION

[0052] In order to have a clearer understanding of the technical features, purposes and effects of the invention, the specific embodiments of the present invention are now described with reference to the accompanying drawings. The same reference numerals in the drawings represent components with the same structure or similar structures but the same functions.

[0053] In this document, “illustrative” means “serving as an example, instance or illustration”, and any diagram or implementation described in this document as “illustrative” should not be interpreted as a more preferred or more advantageous technical solution.

[0054] In this article, "first", "second", etc. do not indicate their importance or order, but are only used to indicate the difference between each other for the convenience of document description.

[0055] Figure 1 The figure is a flowchart of an exemplary embodiment of a method for generating a welding path based on a laser welding device. Figure 2 and Figure 3 The figure is a schematic diagram illustrating the implementation principle of a welding path generation method based on a laser welding device. The laser welding device includes a rotating member and a welding head 10. The rotating member is used to fix the welding part and rotate about a rotation axis O. The welding head 10 is arranged along a first direction Y perpendicular to the rotation axis O and faces the welding part fixed to the rotating member. The welding head 10 is capable of moving relative to the rotating member in the first direction Y and a second direction X, respectively. The second direction X is perpendicular to the rotation axis O and the first direction Y. By driving the rotating member to rotate and associating the movement of the welding head 10 in the first direction Y and the second direction X, the welding head 10 can continuously weld the welding part fixed to the rotating member. The welding path generation method includes the following steps:

[0056] Step S10: Based on the size of the welding contour, use Computer Aided Design (CAD) software to draw a computer drawing of the welding contour line S. Figure 2 ,Computer-aided design software facilitates the accurate drawing of the welding contour line S, and can export the data of each point on the welding contour line S.

[0057] Step S20 : ​​establishing a coordinate system corresponding to the laser welding device in the computer drawing, wherein the longitudinal axis Yc of the coordinate system is parallel to the first direction Y, and the transverse axis Xc of the coordinate system is parallel to the second direction X.

[0058] Step S30: Select a starting weld point S0 and several calibration weld points Sn on the weld outline in the computer drawing. Set the rotation axis O and the starting weld point S0 to the specified coordinates. In the exemplary embodiment, the rotation axis O is set to the origin of the coordinate system to facilitate subsequent calculations.

[0059] Step S40: Connect the rotation axis O and the starting welding point S0 to form the welding starting line R0, and connect the rotation axis O and each calibration welding point Sn to form a welding calibration line Rn. The angle required for each welding calibration line Rn to rotate around the rotation axis O in the same circumferential direction until it coincides with the welding starting line R0 is recorded as the calibration angle θn. Use computer-aided design software to calculate the length and calibration angle θn of the welding calibration line Rn of each calibration welding point Sn. In the exemplary embodiment, the angle between the welding calibration lines Rn of each adjacent calibration welding point Sn is equal, and the angle is set to 0.1 degrees. Therefore, there are 3600 welding calibration lines Rn in total. For clarity, Figure 2 Only one calibration welding point Sn and one welding calibration line Rn are schematically drawn. Figure 3 , after the welding contour line S rotates around the rotation axis O by the calibration angle θn corresponding to the calibration welding point Sn, the calibration welding point Sn is located on the welding starting line R0 or on the extension line of the welding starting line R0.

[0060] Step S50: Calculate the coordinates of each calibration welding point Sn during welding using the coordinates of the rotation axis O and the starting welding point S0 and the length of the welding calibration line Rn of each calibration welding point Sn. Figure 4 This is a partial flow chart of the welding path generation method based on the laser welding device. Figure 4 and combined Figure 2 and Figure 3 In the exemplary embodiment, step S50 specifically includes:

[0061] Step S51: Calculate the length of the welding starting line R0 using the coordinates of the rotation axis O and the starting welding point S0. Figure 2 , the position of the rotation axis O is the origin of the coordinate system (0,0), and the coordinates (X0, Y0) of the starting welding point S0 are known set coordinates, so the length of the welding starting line R0 can be calculated by the formula Calculated.

[0062] Step S52: Calculate the angle between the welding starting line R0 and the horizontal axis Xc using the coordinates of the rotation axis O and the starting welding point S0, and record it as the initial angle θ. The specific initial angle θ is calculated by Calculated.

[0063] Step S53: Calculate the change in the coordinates of the starting welding point S0 to the coordinates of each calibration welding point Sn on the horizontal axis Xc and the vertical axis Yc using the length of the welding starting line R0, the initial angle θ, and the length of the welding calibration line Rn of each calibration welding point Sn. Specifically, the calculation is performed using the following formula:

[0064] ΔX=(R0-Rn)cosθ.

[0065] ΔY=(R0-Rn)sinθ.

[0066] Where R0 represents the length of the welding starting line R0, Rn represents the length of the welding calibration line Rn, θ represents the initial angle, ΔX represents the change in the coordinates of the starting welding point S0 to the calibration welding point Sn on the horizontal axis Xc, that is, Xn-X0, and ΔY represents the change in the coordinates of the starting welding point S0 to the calibration welding point Sn on the horizontal axis Yc, that is, Yn-Y0.

[0067] Step S54: Calculate the coordinates of each calibration point Sn during welding using the coordinates of the starting point S0 and the change in coordinates from the starting point S0 to each calibration point Sn on the horizontal axis Xc and the vertical axis Yc. Using the coordinates (X0, Y0) of the starting point S0, ΔX, and ΔY, the coordinates (Xn, Yn) of each calibration point Sn can be calculated as (X0 + ΔX, Y0 + ΔY).

[0068] In this exemplary embodiment, the length of the weld calibration line Rn, as well as the coordinates of the rotation axis O and the starting weld point S0, obtained in step 40, are imported into the electronic CAM system's programmable logic controller (PLC) via the PLC web function. This data is then read into the PLC DB block array via a command. The PLC calculates the coordinates of each calibration weld point Sn during welding, thereby reducing labor costs while providing accurate calculation results that can be easily retrieved and used by the electronic CAM system.

[0069] Step S60: The length of the welding calibration line Rn of each calibration welding point Sn and the coordinates during welding are imported into the electronic cam system used to control the movement of the rotating part and the welding head 10, and the electronic cam system is used to generate a welding path that enables the welding head 10 to pass through the welding contour of the weldment at a uniform speed. Figure 5 This is a partial flow chart of the welding path generation method based on the laser welding device. Figure 5 In the exemplary embodiment, step S60 specifically includes:

[0070] Step S61: Import the length of the welding calibration line Rn of each calibration welding point Sn and the coordinates during welding into the programmable logic controller of the electronic cam system.

[0071] Step S62: The electronic cam system calculates the rotational speed ratio of the rotating part when the welding head 10 passes through each calibration welding point Sn at a uniform speed based on the length of the welding calibration line Rn of each calibration welding point Sn. The calculation is specifically performed using the following formula:

[0072] V=W*Rn.

[0073] Where V represents the linear velocity of the welding head 10 as it passes through each calibration weld point Sn, Rn represents the length of the weld calibration line Rn, and W represents the rotational speed of the rotating part. Because the linear velocity of the welding head 10 must remain consistent as it passes through each calibration weld point Sn, the length of the weld calibration line Rn is inversely proportional to the rotational speed of the rotating part. This provides data on the proportional relationship between the rotational speeds of the rotating part when the welding head 10 passes through each calibration weld point Sn at a uniform speed.

[0074] Step S63: The electronic CAM system creates a virtual spindle and generates a CAM table based on the rotational speed ratio of the rotating component as the welding head 10 passes through each calibrated weld point Sn at a constant speed. The virtual spindle's speed is defined based on the known linear speed of the welding head 10 as it passes through each calibrated weld point Sn. The CAM table is also generated based on the rotational speed ratio data of the rotating component. The electronic CAM system uses the CAM table to control the relative motion of the rotating component and the welding head 10, ensuring that the distance between the welding head 10 and the weld point remains constant and that the welding head 10 passes through the weld point at a constant speed.

[0075] The welding path generation method of the laser welding device provided by the present invention obtains the welding path by calculation, and sets the corresponding rotation speed for the rotating part in the electronic cam system according to the change of the welding path. Compared with the welding path generated by the teaching method, the welding path generated by the welding path generation method provided by the present invention maintains a constant distance between the welding head 10 and the welding point, and the welding head 10 passes through the welding point at a constant speed, thereby improving the welding quality and saving time and effort when changing the welded part.

[0076] Figure 6 FIG. 1 is a flow chart of another exemplary embodiment of a method for generating a welding path based on a laser welding device. Figure 6 , the welding path generation method also includes:

[0077] Step 70: After calculating the length of the welding calibration line Rn for each calibration welding point Sn, the calibration welding point Sn whose length difference between the welding calibration line Rn and the welding starting line R0 is less than a preset range is eliminated and not used for calculation in subsequent steps. In existing laser welding devices, the movement accuracy of the rotating parts and the welding head 10 can only be maintained within a certain range, and the welding range of the welding head 10 can cover slight errors to ensure welding quality. When the length difference between the welding calibration line Rn and the welding starting line R0 is less than a preset range, the change in the length of the welding calibration line Rn will not affect the welding quality. It can be regarded as if the length of the welding calibration line Rn has not changed and the calculation of the weld point is ignored, which can reduce the calculation without affecting the welding quality.

[0078] Reference Figure 6 , the welding path generation method also includes:

[0079] Step 80: Use the machine vision system to capture the weldment mounted on the rotating component. The generated CAM table is then offset based on the position of the starting weld point S0 as determined by the machine vision system. The machine vision system automatically corrects the CAM table at the start of welding to prevent any slight offset in the weldment during assembly that could affect weld quality.

[0080] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0081] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation scheme or changes that do not deviate from the technical spirit of the present invention, such as the combination, division or repetition of features, should be included in the scope of protection of the present invention.

Claims

1. A method for generating a welding path for a laser welding device, wherein the laser welding device comprises a rotating member and a welding head, wherein the rotating member is used to fix the welding member and rotate about a rotation axis, wherein the welding head is arranged along a first direction perpendicular to the rotation axis and faces the welding member fixed to the rotating member, and wherein the welding head can move relative to the rotating member along the first direction and a second direction, respectively, wherein the second direction is perpendicular to the rotation axis and the first direction, wherein: The welding path generation method comprises the following steps: Based on the dimensions of the weld contour, a computer drawing of the weld contour line is drawn using computer-aided design software; Establishing a coordinate system corresponding to the laser welding device in the computer drawing, wherein the longitudinal axis Yc of the coordinate system is parallel to the first direction, and the transverse axis Xc of the coordinate system is parallel to the second direction; Selecting a starting welding point and several calibration welding points on the weldment contour line in the computer drawing, and setting the rotation axis and the starting welding point to the set coordinates respectively; Connecting the rotation axis and the starting welding point to form a welding starting line, connecting the rotation axis and each of the calibration welding points to form a welding calibration line, recording the angle required for each of the welding calibration lines to rotate around the rotation axis in the same circumferential direction until it coincides with the welding starting line as a calibration angle, and calculating the length of the welding calibration line and the calibration angle of each of the calibration welding points using computer-aided design software; Calculating the coordinates of each of the calibration welding points during welding using the coordinates of the rotation axis and the starting welding point and the length of the welding calibration line of each of the calibration welding points; and The length of the welding calibration line of each calibrated welding point and the coordinates during welding are imported into the electronic cam system used to control the movement of the rotating part and the welding head, and the electronic cam system is used to generate a welding path that enables the welding head to pass through the welding contour of the welded part at a uniform speed.

2. The welding path generation method according to claim 1, wherein: Step: Calculating the coordinates of each calibration welding point during welding using the coordinates of the rotation axis and the starting welding point and the length of the welding calibration line of each calibration welding point, including: Calculating the length of the welding starting line using the coordinates of the rotation axis and the starting welding point; Calculate the angle between the welding starting line and the horizontal axis Xc using the coordinates of the rotation axis and the starting welding point, and record it as the initial angle; Calculating the change in the coordinates of the starting welding point to the coordinates of each of the calibration welding points on the horizontal axis Xc and the vertical axis Yc using the length of the welding starting line, the initial angle, and the length of the welding calibration line of each of the calibration welding points; and The coordinates of each calibration welding point during welding are calculated using the coordinates of the starting welding point and the variation from the coordinates of the starting welding point to the coordinates of each calibration welding point on the horizontal axis Xc and the vertical axis Yc.

3. The welding path generation method according to claim 2, wherein: The change in the coordinates of the starting welding point to the coordinates of each calibration welding point on the horizontal axis Xc and the vertical axis Yc is calculated using the following formula: ΔX=(R0-Rn)cosθ; ΔY=(R0-Rn)sinθ; Where R0 represents the length of the welding start line, Rn represents the length of the welding calibration line, θ represents the initial angle, ΔX represents the change in coordinates from the starting welding point to the calibration welding point on the horizontal axis Xc, and ΔY represents the change in coordinates from the starting welding point to the calibration welding point on the horizontal axis Yc.

4. The welding path generation method according to claim 1, wherein: Step: importing the length of the welding calibration line of each calibration welding point and the coordinates during welding into an electronic cam system for controlling the movement of the rotating part and the welding head, and using the electronic cam system to generate a welding path that enables the welding head to pass through the welding contour of the welded part at a uniform speed, including: Importing the length of the welding calibration line and the coordinates of each calibration welding point during welding into the electronic cam system; The electronic cam system calculates the rotational speed ratio of the rotating member when the welding head passes through each of the calibration welding points at a uniform speed according to the length of the welding calibration line of each of the calibration welding points; and The electronic cam system creates a virtual main axis and generates a cam table according to the rotation speed ratio of the rotating part when the welding head passes through each of the calibrated welding points at a uniform speed.

5. The welding path generation method according to claim 4, wherein: The rotational speed ratio of the rotating part when the welding head passes through each of the calibration welding points at a uniform speed is calculated using the following formula: V=W*Rn; Wherein, V represents the linear velocity of the welding head when passing through each calibration welding point, Rn represents the length of the welding calibration line, and W represents the rotation speed of the rotating part.

6. The welding path generation method according to claim 4, wherein: The welding path generation method further includes: using a machine vision system to photograph the welding part fixed to the rotating part, and performing offset correction on the generated cam table according to the position of the starting welding point in the machine vision system.

7. The welding path generation method according to claim 1, wherein: The welding path generation method further includes: after calculating the length of the welding calibration line of each of the calibration welding points, eliminating the calibration welding points whose difference between the length of the welding calibration line and the welding start line is less than a preset range and not using them for calculation in subsequent steps.

8. The welding path generation method according to claim 1, wherein: In the step of calculating the coordinates of each calibration welding point during welding using the coordinates of the rotation axis and the starting welding point and the length of the welding calibration line of each calibration welding point, the coordinates of the rotation axis and the starting welding point and the length of the welding calibration line of each calibration welding point are imported into the programmable logic controller of the electronic cam system, and the coordinates of each calibration welding point during welding are calculated using the programmable logic controller.

9. The welding path generation method according to claim 1, wherein: The rotation axis is set to the origin of the coordinate system.

10. The welding path generation method according to claim 1, wherein: In the step: a starting welding point and several calibration welding points are selected on the weldment contour line in the computer drawing, the rotation axis and the starting welding point are moved to known coordinates respectively, and the angles between the welding calibration lines of each two adjacent calibration welding points are equal.

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