Multi-wire welding trajectory parameter optimization method based on different welding seam routes

Abstract

The application discloses a multi-wire welding track parameter optimization method based on different welding seam routes, which comprises the following steps: measuring the thickness of a workpiece, determining the number of welding wires and the welding speed, and considering the influence of a groove; determining the position of a flat welding seam to be welded, and setting multi-wire welding parameters; when welding is performed by using a first welding wire, the pulse setting is double pulse, and the pulse setting of the remaining welding wires is single pulse; according to different kinds of welding seam routes and the welding speed of the first welding wire, the welding speed of the next welding wire is adjusted in sequence, so that the interval distance of each welding wire is kept consistent during operation; after welding is completed, all the wire feeding devices are moved to the initial position, the workpiece is cooled, and then is transferred to a set position, and the next round of welding is performed. By using the application, the construction efficiency of multi-wire welding of different welding seam routes can be improved, and the welding quality reliability can be ensured.

Description

Parameter Optimization Method for Multi-Wire Welding Trajectory Based on Different Weld Seam Paths Technical Field

[0001] This invention relates to a welding trajectory optimization design method, and more particularly to a method for optimizing welding trajectory parameters in multi-wire welding when different weld seam routes are used. Background Technology

[0002] In industrial sectors such as engineering machinery, shipbuilding, and high-rise buildings, welding processes for different steel structures are key manufacturing steps. Multi-wire welding is widely used due to its high deposition efficiency, high welding speed, stable welding process, and good welding performance. Currently, dual-wire technology is commonly used, and its efficiency is more than twice that of ordinary single-wire welding.

[0003] Multi-wire welding involves welding multiple welding wires sequentially. Taking dual-wire welding technology as an example, it consists of two MIG / MAG welding power sources (one master and one slave), two wire feeding devices, and one welding torch. The two welding power sources have communication and coordination functions. Generally, dual-wire welding uses two welding wires controlled by the master and slave to weld simultaneously with a small interval. Typically, a phase-shifting method is used, where the master is in the pulse peak stage while the slave is in the pulse base stage. This reduces welding interference to less than a quarter of the original. Currently, it is common to use DC, high current, and low voltage for the first wire, and AC, low current, and high voltage for the second wire. This makes it easier to form a molten pool at the weld joint, and the final workpiece surface is smooth, avoiding the formation of gourd-shaped welds.

[0004] Welding is characterized by high temperature, instantaneous operation, and dynamic nature. Furthermore, multi-wire welding involves repeated thermal cycles of heat on the weld seam and base material. Therefore, high standards are required for the wire movement trajectory and welding speed to prevent premature solidification or overheating of the welded component. Current multi-wire welding technology is still immature, making it prone to improper control of wire movement trajectory and welding speed, resulting in weld quality that is sometimes even worse than that of traditional welding methods. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method for optimizing multi-wire welding trajectory parameters based on different weld seam routes, which can improve welding efficiency and ensure the reliability of welding quality.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] The present invention provides a method for optimizing multi-wire welding trajectory parameters for different weld seam paths, comprising the following steps:

[0008] A method for optimizing multi-wire welding trajectory parameters based on different weld seam routes, characterized by the following steps:

[0009] Step 1: Measure the workpiece thickness and determine the number of welding wires and welding speed. If the workpiece has a bevel, the thickness of the bevel blunt edge shall be used as the workpiece thickness. For workpieces with a thickness of less than 12mm, use double welding wires. For every 5mm increase in thickness, add one welding wire to assist welding. The number of welding wires shall not exceed 4.

[0010] Step 2: Determine the location of the planar weld to be welded, and set the multi-wire welding parameters. These parameters include the number of welding wires (n) used in the multi-wire welding process, numbered sequentially from 1 to n according to the order of use; the voltage U1, current I1, and pulse frequency f1 used when welding with the first welding wire; and the voltage U1 used when welding with the last welding wire. n Current I n and f n The distance between two adjacent welding wires when they move in a straight line is m;

[0011] The voltage used when welding with the next welding wire is greater than the voltage used when welding with the previous welding wire, and the current used when welding with the next welding wire is less than the current used when welding with the previous welding wire; where U n The value of U1 is set to 60% of the specified voltage U, and the value of U1 is set to U. n 80%; the magnitude of I1 is taken as 60% of the specified current, I n The value is set to 80% of I1, and the specified voltage and current are the voltage U and current I specified in GB / T 13164-2003 corresponding to the diameter of the welding wire;

[0012] For multi-wire welding with n greater than 2, the intermediate welding wire parameters are characterized by gradually decreasing current and gradually increasing voltage, forming a stepped parameter configuration; i.e., U1 <U2<...U k <... n , I1>I2>...>I k >...>I n The voltage U used when welding with the kth welding wire is... k For U1+(U n -U1) (k-1) / (n-1), the current I used when welding with the k-th welding wire. k For I1+(I n -I1) (k-1) / (n-1);

[0013] ​When welding with the first welding wire, the pulse used is set to double pulse, and when welding with the second to the nth welding wire, the pulse used is single pulse;

[0014] Step 3: Determine the welding wire trajectory based on the weld seam of the workpiece to be welded;

[0015] Step 4: Set the welding speed of the first welding wire to v1, and set the welding speeds of the second to nth welding wires according to the weld trajectory. The specific steps are as follows:

[0016] In the first step, when the welding trajectories of the (k+1)th welding wire and the kth welding wire are parallel, their speeds are kept consistent. That is, when two adjacent welding wires are running on the same straight line, v(k+1) = v(k).

[0017] The second step involves timing Tk when the direction of motion of the k-th welding wire deviates by an angle θ from the welding trajectory of the straight line before the turn. Timing Tk continues until the direction of motion of the (k+1)-th welding wire returns to parallel with the direction of motion of the k-th welding wire, at which point Tk resets to 0. During this process, the welding speed of the k-th welding wire... The welding speed v(k+1) of the next welding wire remains unchanged, and the value of v(k+1) is obtained by the following formula:

[0018] v(k+1) =

[0019] Where θ represents the angle θ that the direction of movement of the k-th welding wire deviates from the welding trajectory of the straight line before the turn; It represents the time elapsed after the direction of motion of the k-th welding wire deviates from the welding trajectory of the straight line before the turn by an angle θ, and returns to 0 when the direction of motion of the (k+1)-th welding wire returns to parallel with the direction of motion of the k-th welding wire again;

[0020] Thirdly, if the k-th welding wire is about to move in a circular arc with radius r, and the (k+1)-th welding wire is still moving in a straight line, then timer Tk starts and continues until the (k+1)-th welding wire and the k-th welding wire are moving in the same circular arc, at which point Tk returns to 0; during this process, the welding speed of the k-th welding wire... The welding speed v(k+1) of the next welding wire remains unchanged, and the value of v(k+1) is obtained by the following formula:

[0021] = =

[0022] Where α= , represents the angle at which the k-th welding wire travels on the arc; r represents the radius of the arc when the k-th welding wire will move; This represents the time elapsed when the k-th welding wire will make a circular motion, and returns to 0 when the (k+1)-th welding wire also makes a circular motion;

[0023] Step 5: Weld each welding wire at the welding speed of Step 4, and the speed of the first welding wire shall be determined according to the material of the workpiece and in accordance with GB / T 13164-2003.

[0024] When the kth welding wire reaches the end of the welding path, the welding work of that wire is stopped, and the wire feeding device moves to the initial position of the kth welding wire. At this time, the speed of the (k+1)th welding wire remains unchanged and continues until the welding work of that wire is completed. When the last welding wire also completes its welding work, the welding work of the workpiece is considered to be completed.

[0025] Step 6: Wait for all wire feeding devices to move to their initial positions and for the workpiece to cool down before transferring it to the set position and proceeding to the next round of welding.

[0026] Compared with the prior art, the advantages of using the present invention are as follows:

[0027] This invention enables the distance between adjacent welding wires to remain consistent during multi-wire welding, and the welding speed of each welding wire depends on the previous welding wire, ensuring that there is no premature solidification of the local molten pool or local overheating during welding, thereby improving welding quality and welding efficiency. Attached Figure Description

[0028] Figure 1 is a schematic diagram of the welding process using multi-wire welding technology;

[0029] Figure 2 is a schematic diagram of the turning angle of the welding route;

[0030] Figure 3 is a schematic diagram when the welding trajectories of the (k+1)th welding wire and the kth welding wire are parallel;

[0031] Figure 4 is a schematic diagram when the direction of movement of the k-th welding wire deviates by an angle θ from the welding trajectory of the straight line before the turn.

[0032] Figure 5 is a schematic diagram when the k-th welding wire will make a circular arc motion with radius r, and the (k+1)-th welding wire is still making a linear motion. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0034] As shown in Figure 2, this method is applicable to welding workpieces that do not contain welds with angles greater than 90°. Welds with angles of 18° and 31° in Figure 2 are suitable for this method, while welds with angles of 118° are not. For U-shaped and H-shaped welds, the spacing between parallel welds should be greater than the distance m between adjacent welding wires during linear movement; otherwise, the workpiece may be subjected to repeated heating in certain areas, affecting the welding quality.

[0035] The multi-wire welding trajectory parameter optimization method of the present invention based on different weld seam routes, as shown in the attached figure, includes the following steps:

[0036] Step 1: Measure the workpiece thickness and determine the number of welding wires and welding speed. If the workpiece has a bevel, the thickness of the bevel's blunt edge is used as the workpiece thickness. For workpieces with a thickness less than 12mm, use double welding wires. For every 5mm increase in thickness, add one welding wire to assist welding, generally not exceeding 4 welding wires.

[0037] The presence of a bevel alters the position of the first welding wire in multi-wire welding, resulting in increased penetration depth but decreased weld width. To avoid burn-through of the workpiece, first determine the workpiece material thickness. If a bevel exists, use the bevel blunt edge thickness as a reference for the workpiece thickness. The welding speed of the first welding wire is determined based on the workpiece material, directly referring to GB / T13164-2003. Generally, the welding speed is controlled between 12 and 20 mm / s.

[0038] Step 2: Determine the location of the planar weld to be welded. Based on the workpiece material and welding requirements, set the multi-wire welding parameters, such as voltage and current, referring to GB / T 13164-2003 for details. The multi-wire welding parameters include the number of welding wires n used in multi-wire welding (numbered 1 to n sequentially according to the order of use), the voltage U1, current I1, and pulse frequency f1 used when welding with the first welding wire, and the voltage U1 used when welding with the last welding wire. n Current I n and f n The distance between two adjacent welding wires when they move in a straight line is m.

[0039] When welding with the next welding wire, the voltage used is greater than that used when welding with the previous welding wire, and the current used when welding with the next welding wire is less than that used when welding with the previous welding wire. Where U n The value of U1 is set to 60% of the specified voltage U, and the value of U1 is set to U. n 80%; the magnitude of I1 is taken as 60% of the specified current, I nThe value is set to 80% of I1. The specified voltage and current are the voltage U and current I specified in GB / T 13164-2003 corresponding to the diameter of the welding wire.

[0040] For multi-wire welding with n greater than 2, the intermediate welding wire parameters are characterized by gradually decreasing current and gradually increasing voltage, forming a stepped parameter configuration, i.e., U1. <U2<...U k <... n , I1>I2>...>I k >...>I n The voltage U used when welding with the kth welding wire is... k For U1+(U n -U1) (k-1) / (n-1), the current I used when welding with the k-th welding wire. k For I1+(I n -I1) (k-1) / (n-1).

[0041] When welding with the first welding wire, the pulse is set to double pulse, and when welding with the second to the nth welding wire, the pulse is set to single pulse to facilitate stirring of the molten pool.

[0042] Step 3: Determine the welding wire trajectory based on the weld seam of the workpiece to be welded.

[0043] Step 4: Set the welding speed of the first welding wire to v1, and set the welding speeds of the second to nth welding wires according to the weld trajectory. The specific steps are as follows:

[0044] In the first step, when the welding trajectories of the (k+1)th welding wire and the kth welding wire are parallel, their speeds are kept consistent. That is, when two adjacent welding wires run on the same straight line, v(k+1) = v(k). As shown in Figure 3.

[0045] The second step involves timing Tk when the direction of motion of the k-th welding wire deviates by an angle θ from the welding trajectory of the straight line before the turn. Timing Tk resumes until the direction of motion of the (k+1)-th welding wire returns to parallel with the direction of motion of the k-th welding wire, at which point Tk resets to 0. During this process, the welding speed of the k-th welding wire... The welding speed v(k+1) of the next welding wire remains constant, while the welding speed of the next welding wire changes to keep the distance m between the two wires constant. The value of v(k+1) is derived from the following formula:

[0046] v(k+1) =

[0047] Where θ represents the angle θ that the direction of movement of the k-th welding wire deviates from the welding trajectory of the straight line before the turn;​ It represents the time elapsed after the direction of motion of the k-th welding wire deviates from the welding trajectory of the straight line before the turn by an angle θ, and returns to 0 when the direction of motion of the (k+1)-th welding wire returns to parallel with the direction of motion of the k-th welding wire again.

[0048] The detailed derivation of the value of v(k+1) is as follows:

[0049] As shown in Figure 4, after the k-th welding wire passes through the turning angle for a time Tk, the distance from the turning angle is Tk. v(k), where the distance between the (k+1)th welding wire and the turning angle is x, since the interval m between two adjacent welding wires remains constant, and the turning angle is known to be θ, the following relationship exists. + - = 0, we can calculate the change of the distance x between the (k+1)th welding wire and the corner with time Tk, and then according to v(k+1) = This allows us to calculate the change in the speed of the (k+1)th welding wire while keeping the distance m between two adjacent welding wires constant.

[0050] In practice, since the distance m between two adjacent welding wires is very small, the situation where there are multiple turns between two adjacent welding wires is not considered.

[0051] The third step involves timing Tk when the k-th welding wire is about to move in a circular arc with radius r, while the (k+1)-th welding wire is still moving in a straight line. Timing Tk resumes to 0 when the (k+1)-th welding wire and the k-th welding wire are both moving on the same circular arc. During this process, the welding speed of the k-th welding wire... The welding speed v(k+1) of the next welding wire remains constant, while the welding speed of the next welding wire changes to keep the distance m between the two wires constant. The value of v(k+1) is derived from the following formula:

[0052] =

[0053] Where α= , represents the angle at which the k-th welding wire travels on the arc; r represents the radius of the arc when the k-th welding wire will move; This represents the time elapsed when the k-th welding wire will make a circular motion, and returns to 0 when the (k+1)-th welding wire also makes a circular motion.

[0054] The specific calculation steps are as follows:

[0055] As shown in Figure 5, after the k-th welding wire enters the arc for time Tk, the distance it travels on the arc is Tk. v(k), from the formula α= , the angle α at which the k-th welding wire runs on the arc can be obtained. As shown in Figure 5, draw auxiliary lines, where r - b is the minimum distance between the extension line of the movement path of the (k + 1)-th welding wire and the k-th welding wire. Among them , , . At this time, the distance between the (k + 1)-th welding wire and the arc is set as x. Since the interval distance m between adjacent welding wires remains unchanged, there is a relational expression . Substitute the above values to obtain .

[0056] Then, according to v(k + 1)= , the change in the movement speed of the (k + 1)-th welding wire can be calculated when the interval distance m between adjacent welding wires is to be kept unchanged, that is

[0057] = =

[0058] In actual situations, since the interval distance m between adjacent welding wires is very small, there is no situation where r < m. And when the k-th welding wire leaves the arc, it can also be calculated according to the above formula and of the relative magnitudes.

[0059] Step Five: Each welding wire is welded at the welding speed of Step Four, and the speed of the first welding wire is directly determined according to the material of the welded workpiece by referring to GB / T 13164 - 2003.

[0060] When the k-th welding wire reaches the end of the welding path, the welding work of this welding wire is stopped, and the wire feeding device runs to the initial position of the k-th welding wire. At this time, the speed of the (k + I)-th welding wire remains unchanged and continues until the welding work of this welding wire is completed. When the welding work of the last welding wire is also completed, it is considered that the welding work of this workpiece is completed.

[0061] Step Six: Wait for all wire feeding devices to move to the initial position, and after the workpiece cools, transfer it to the set position and perform the next round of welding.

Claims

1. A method for optimizing multi-wire welding trajectory parameters based on different weld seam paths, characterized in that... Includes the following steps: Step 1: Measure the workpiece thickness and determine the number of welding wires and welding speed. If the workpiece has a bevel, the thickness of the bevel's blunt edge is used as the workpiece thickness. For workpieces with a thickness less than 12mm, use double welding wires. For every 5mm increase in thickness, add one welding wire to assist welding, with a maximum of 4 welding wires. Step 2: Determine the location of the planar weld to be welded and set the multi-wire welding parameters. These parameters include the number of welding wires n used in multi-wire welding (numbered 1 to n sequentially according to their usage order), the voltage U1, current I1, and pulse frequency f1 used when welding with the first welding wire, and the voltage U1 used when welding with the last welding wire. n Current I n and f n The distance between two adjacent welding wires during linear motion is m; the voltage used when welding with the latter welding wire is greater than the voltage used when welding with the former welding wire, and the current used when welding with the latter welding wire is less than the current used when welding with the former welding wire; where U n The value of U1 is set to 60% of the specified voltage U, and the value of U1 is set to U. n 80%; the magnitude of I1 is taken as 60% of the specified current, I n The value is set to 80% of I1. The specified voltage and current are the voltage U and current I specified in GB / T 13164-2003 corresponding to the diameter of the welding wire. For multi-wire welding with n greater than 2, the intermediate welding wire parameters are that the current gradually decreases and the voltage gradually increases, forming a stepped parameter; that is, U1 <U2<...U k <... n , I1>I2>...>I k >...>I n The voltage U used when welding with the kth welding wire is... k For U1+(U n -U1)​ (k-1) / (n-1), the current I used when welding with the k-th welding wire. k For I1+(I n -I1) (k-1) / (n-1); When using the first welding wire for welding, the pulse used is set to double pulse, and when using the second to nth welding wires, the pulse used is single pulse; Step 3: Determine the welding trajectory of the welding wires from the weld seam of the workpiece to be welded; Step 4: Set the welding speed of the first welding wire to v1, and set the welding speed of the second to nth welding wires according to the weld seam trajectory. The specific steps are as follows: First, when the welding trajectories of the (k+1)th welding wire and the kth welding wire are parallel, the speed is kept consistent, that is, when two adjacent welding wires run on the same straight line, v(k+1) = v(k); Second, when the direction of movement of the kth welding wire deviates from the welding trajectory of the straight line before the turning angle by an angle θ, Tk starts timing until the direction of movement of the (k+1)th welding wire is parallel to the direction of movement of the kth welding wire again, Tk returns to 0; During this process, the welding speed of the kth welding wire The welding speed v(k+1) of the next welding wire remains unchanged, and the value of v(k+1) is obtained by the following formula: v(k+1) = Where θ represents the angle θ that the direction of movement of the k-th welding wire deviates from the welding trajectory of the straight line before the turn; This represents the time elapsed after the direction of motion of the k-th welding wire deviates by an angle θ from the straight welding trajectory before the turn, and returns to 0 when the direction of motion of the (k+1)-th welding wire returns to parallel with the direction of motion of the k-th welding wire; In the third step, if the k-th welding wire is about to perform a circular arc motion with radius r, and the (k+1)-th welding wire is still moving in a straight line, then Tk starts timing, and returns to 0 when the (k+1)-th welding wire moves on the same arc as the k-th welding wire; during this process, the welding speed of the k-th welding wire... The welding speed v(k+1) of the next welding wire remains unchanged, and the value of v(k+1) is obtained by the following formula: = = Where α= , represents the angle at which the k-th welding wire travels on the arc; r represents the radius of the arc when the k-th welding wire will move; This represents the time elapsed when the k-th welding wire begins its circular motion, and returns to 0 when the (k+1)-th welding wire also begins its circular motion; Step 5: Each welding wire is welded at the welding speed specified in Step 4, and the speed of the first welding wire is determined according to the material of the workpiece, based on GB / T 13164-2003; When the k-th welding wire reaches the end of the welding path, the welding work of that wire is stopped, and the wire feeding device moves to the initial position of the k-th welding wire. At this time, the speed of the (k+1)-th welding wire remains unchanged and continues until the welding work of that wire is completed; When the last welding wire also completes its welding work, the welding work of the workpiece is considered complete; Step 6: Wait for all wire feeding devices to move to their initial positions, and after the workpiece cools down, transfer it to the set position and begin the next round of welding.

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