A non-glossy direct current butt welding machine

Abstract

The present application relates to the technical field of butt welding machine, especially to a non-light direct current butt welding machine, comprising: a welding mechanism, comprising a first butt welding assembly, a second butt welding assembly and a direct current transformer; a linkage mechanism, comprising a left moving plate, a right moving plate, a left eccentric shaft and a right eccentric shaft; a driving mechanism, comprising a plurality of servo motors and a top forging oil cylinder; a detection mechanism; a control mechanism, used to weld workpieces by controlling the current value of direct current during welding, used to press workpieces by controlling the rotation angle of the eccentric shaft, used to top forge workpieces by controlling the relative movement of the left moving plate approaching the right moving plate driven by the top forging oil cylinder, used to adjust the height of the left moving plate and the right moving plate respectively by controlling the servo motor to drive the linkage mechanism, and used to adjust the holding time of the top forging pressure according to the total energy of the welded workpiece, and used to correct the top forging displacement target value according to the change rate of the top forging pressure. The present application realizes the improvement of welding efficiency and welding precision.

Description

Technical Field

[0001] This invention relates to the field of butt welding machine technology, and more particularly to a non-light DC butt welding machine. Background Technology

[0002] In existing technologies, the non-light DC welding machine is based on arc-free resistance heating. It uses DC power supplies such as thyristor rectification and IGBT inverters to provide stable current, which provides more uniform heating and reduces spatter and oxidation compared to AC power. It uses highly conductive and wear-resistant copper alloy electrodes, and the electrode shape is optimized according to the workpiece shape to reduce contact resistance. The pre-pressure, welding pressure and upsetting pressure are adjusted through a hydraulic / pneumatic system.

[0003] Chinese Patent Publication No. CN117483923A discloses a DC pulse TIG welding machine. The welding machine body includes a welding machine base and a welding machine housing. The welding machine housing is detachably mounted on the top of the welding machine base. Support wheels are installed at the four corners of the bottom of the welding machine base. Heat dissipation holes are provided on the front and rear sides of the welding machine housing. Connection ports and control switches for connecting and controlling external devices are respectively provided on both sides of the welding machine housing. The heat dissipation holes, connection ports, and control switches are all located in the upper half of the welding machine housing. A protective sleeve is slidably fitted onto the outer side of the welding machine housing. The height of the welding machine housing is matched with the height of the heat dissipation holes, connection ports, and control switch areas. A top plate is fixedly connected to the top of the welding machine housing. The bottom area of ​​the top plate matches the outer perimeter area of ​​the top of the protective sleeve. A slot matching the top of the protective sleeve is opened at the bottom of the top plate, and the top of the protective sleeve is inserted into the slot. Locking components are provided on both sides of the protective sleeve. Support components are provided on the front and rear sides of the protective sleeve. A positioning component is provided at the bottom of the welding machine base. Two U-shaped handles are symmetrically arranged on the top of the protective sleeve, and the bottom ends of the handles are fixedly connected to the front and rear sides of the protective sleeve, respectively. It can be seen that the DC pulse argon arc welding machine has problems such as a large amount of high-temperature metal spatter and oxidation fumes generated during the welding process, unstable heat generated during the welding process due to the periodic change of the alternating current direction, which leads to a decrease in welding effect. Furthermore, the workpiece material hardness variation during the upsetting process, equipment wear or cylinder performance fluctuations, and decreased material plasticity lead to inaccurate upsetting displacement control, resulting in poor weld joint shape, excessive flash, or weak welds. Summary of the Invention

[0004] To address these issues, the present invention provides a non-light DC butt welding machine to overcome the problems in the prior art, such as the large amount of high-temperature metal spatter and oxidation fumes generated during the welding process, the unstable heat generated during the welding process due to the periodic change in the direction of the alternating current, which leads to a decrease in welding effect, and the inaccurate control of the upsetting displacement due to variations in the hardness of the workpiece material, equipment wear or cylinder performance fluctuations, and a decrease in material plasticity during the upsetting process, which leads to poor weld joint shape, excessive flash, or weak weld.

[0005] To achieve the above objectives, the present invention provides a non-light DC welding machine, comprising:

[0006] A welding mechanism for clamping a workpiece for welding and feeding includes a first welding assembly for applying direct current to the workpiece, a second welding assembly horizontally disposed on one side of the first welding assembly, and a DC transformer connected to the first welding assembly and the second welding assembly respectively for outputting direct current.

[0007] The linkage mechanism, which is connected to the welding mechanism, includes a left movable plate disposed below the first welding assembly for supporting the workpiece, a right movable plate disposed below the second welding assembly, a left eccentric shaft connected to the left movable plate for adjusting the eccentricity of the left movable plate, and a right eccentric shaft connected to the right movable plate for adjusting the eccentricity of the right movable plate.

[0008] The drive mechanism, which is connected to the linkage mechanism, includes several servo motors for generating driving torque to adjust the height of the welding mechanism and an upsetting cylinder connected to the left moving plate for driving the left moving plate and the right moving plate to move horizontally relative to each other.

[0009] The detection mechanism, which is connected to the welding mechanism, is used to detect the relative movement distance of the left and right moving plates and the upsetting pressure;

[0010] A control mechanism, connected to the welding mechanism, the linkage mechanism, and the drive mechanism, is used to control the current value of the DC power output from the DC transformer during the welding process to weld the workpiece; to control the rotation angles of the first and second welding assemblies around the left and right eccentric axes respectively to clamp the workpiece; to control the upsetting cylinder to drive the left moving plate to move relative to the right moving plate to upset the workpiece; and to control the servo motor to drive the linkage mechanism to adjust the heights of the left and right moving plates respectively.

[0011] It is also used to adjust the holding time of the upsetting pressure according to the total energy input to the workpiece during welding, and to correct the target value of the upsetting displacement according to the rate of change of the upsetting pressure.

[0012] Furthermore, the first welding assembly includes a left electrode disposed above the left moving plate and a left jaw disposed above the left electrode for fixing the workpiece;

[0013] The second welding assembly includes a right electrode disposed above the right moving plate and a right jaw disposed above the right electrode for applying a horizontal clamping force to the workpiece.

[0014] Furthermore, the linkage mechanism also includes:

[0015] The left pressure arm, which is positioned above the left jaw, is used to apply a vertically downward clamping force to the workpiece;

[0016] A left clamping cylinder is connected to the left pressure arm and is used to drive the left pressure arm to move;

[0017] The right pressure arm is positioned above the right jaw and is used to apply a vertically downward clamping force to the workpiece.

[0018] The right clamping cylinder is connected to the right clamping arm and is used to drive the right clamping arm to move.

[0019] Furthermore, the testing institution includes:

[0020] A displacement sensor, connected to the upsetting cylinder, is used to detect the relative movement distance between the left moving plate and the right moving plate;

[0021] A pressure sensor, connected to the upsetting cylinder, is used to detect the upsetting pressure.

[0022] Furthermore, the control mechanism is connected to the DC transformer to obtain the total energy of the welding input workpiece. If the total energy is less than or equal to the preset energy, the holding time of the upsetting pressure is increased.

[0023] Furthermore, the holding time of the upsetting pressure is the difference between the moment when the left clamping cylinder cancels the clamping force applied to the workpiece and the moment when welding ends.

[0024] Furthermore, the total energy is the product of the current output by the DC transformer, the output voltage, and the duration of the welding current during the welding current's duration.

[0025] Furthermore, the control mechanism is connected to the pressure sensor to obtain the rate of change of the upsetting pressure. Under the condition that the rate of change is greater than or equal to the preset rate of change, a displacement compensation amount is added to the effective displacement as the base value, and this compensation amount is used as the corrected target value of the upsetting displacement.

[0026] Furthermore, the effective displacement is the current relative movement distance under the condition that the rate of change is equal to the preset rate of change.

[0027] Furthermore, the rate of change of the upsetting pressure is the ratio of the difference between the upsetting pressure at the end of the unit detection time and the upsetting pressure at the beginning of the unit detection time during the upsetting process of the left moving plate to the unit detection time.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows: the device of the present invention, by setting up a welding mechanism, a linkage mechanism, a driving mechanism, a detection mechanism, and a control mechanism, achieves stable clamping of the workpiece, efficient DC heating welding, precise upsetting control, and dynamic parameter adjustment, effectively overcoming the problems of unstable heat input, severe high-temperature metal spatter, and excessive oxidation fumes caused by the periodic change of current direction in traditional AC butt welding machines, which lead to a decline in welding quality; the use of a DC transformer to provide a stable unidirectional current to the first and second butt welding components significantly improves the heat concentration and thermal efficiency of the welding area, reduces ineffective energy consumption and metal spatter, and suppresses the oxidation reaction rate, thereby improving the weld formation quality and reducing subsequent cleaning costs; the DC voltage is stable, and the fluctuation range is within acceptable limits. The fluctuation range is typically no more than ±10%, far lower than that of AC power. During the welding process, the positive and negative electrodes generate instantaneous high current and high temperature, directly melting the weld joint of the rim without any spatter. The DC current direction is constant and does not change periodically, thus generating constant heat during the welding process and ensuring stable welding quality. At the start of welding, high heat is generated instantaneously, melting the weld joint of the workpiece and completing the upsetting process without preheating or burning, thereby reducing workpiece loss. Because DC non-light welding can reach the upsetting state in about 1 second after the start of welding, the welding time is only about 2 seconds, which is about 1 / 5 of the welding time of conventional AC flash welding machines. The angle between the jaws and the electrodes is adjusted by a servo motor-driven cam mechanism, which can quickly complete model changes and improve production efficiency.

[0029] Furthermore, the device of the present invention adjusts the holding time of the upsetting pressure according to the total energy input to the workpiece through a control mechanism. Since the plastic deformation capacity of the fusion zone is insufficient under low energy input conditions, releasing the upsetting pressure too early will lead to insufficient weld joint strength or microcracks. By establishing a negative feedback relationship between total energy and holding time, the upsetting pressure holding time is automatically extended when the total energy is less than or equal to the preset energy, ensuring that the fusion zone completes the full recrystallization and densification process under high pressure, enhancing the metallurgical bonding strength of the weld joint, avoiding defects such as incomplete welding and incomplete penetration, and improving welding reliability.

[0030] Furthermore, the device described in this invention collects the relative movement distance and upsetting pressure of the left moving plate through a detection mechanism, and the control mechanism dynamically corrects the target value of upsetting displacement based on the rate of change of upsetting pressure. Due to factors such as fluctuations in workpiece material hardness, lag in cylinder response, or mechanical wear, the actual upsetting force may deviate from the set value, thereby causing inaccurate upsetting displacement control, resulting in problems such as excessive flash, misalignment of joints, or local overheating. By introducing the rate of change of pressure as a compensation basis, when the rate of change is greater than or equal to the preset rate of change, the displacement compensation amount is superimposed on the effective displacement to achieve adaptive adjustment of the upsetting stroke, thereby improving the welding consistency of different batches of workpieces under non-ideal conditions.

[0031] Furthermore, the device of the present invention achieves synchronous adjustment of the height of the left and right jaws through the linkage structure of the eccentric shaft, the left moving plate, and the right moving plate, in conjunction with the linkage mechanism driven by the servo motor. This solves the problem of misalignment of the upper and lower electrodes caused by differences in workpiece diameter or assembly deviations, and avoids electrode burnout and uneven heat distribution caused by excessive local contact resistance. At the same time, by controlling the rotation angle of the first welding assembly and the second welding assembly around the eccentric shaft, flexible clamping of the workpiece is achieved, reducing the risk of mechanical damage to the workpiece surface during clamping and improving clamping stability and repeatability accuracy.

[0032] Furthermore, the device of the present invention drives the left and right moving plates to move relative to each other through the top forging cylinder, forming a bidirectional symmetrical force-applying clamping mechanism, which effectively balances the electromagnetic thrust and thermal expansion stress generated during the welding process, prevents the workpiece from axially shifting or deviating during the electric heating stage, ensures the uniformity of current flow through the interface and the stability of contact pressure, and further improves the controllability of the welding process and the consistency of joint quality. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of the non-light DC welding machine according to an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the overall structure of the non-light DC welding machine according to an embodiment of the present invention from another angle;

[0035] Figure 3 This is a front view schematic diagram of the overall structure of the non-light DC welding machine according to an embodiment of the present invention;

[0036] Figure 4 This is a top view schematic diagram of the overall structure of the non-light DC welding machine according to an embodiment of the present invention;

[0037] Explanation of reference numerals: 1-Left clamping cylinder, 2-Right clamping cylinder, 3-Left pressure arm, 4-Right pressure arm, 5-Left jaw, 6-Right jaw, 7-Right electrode, 8-Left electrode, 9-Right moving plate, 10-Left moving plate, 11-Bed, 12-Displacement sensor, 13-Forging cylinder, 14-Left reducer, 15-Left servo motor, 16-First rotating shaft, 17-Connecting rod, 18-Second rotating shaft, 19-DC transformer, 20-Left eccentric shaft, 21-Right eccentric shaft, 22-Right reducer, 23-Right servo motor, 24-Left elevator, 25-Right elevator. Detailed Implementation

[0038] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0039] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0040] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0041] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0042] Please see Figure 1 , Figure 2 , Figure 3 as well as Figure 4 As shown, these are respectively a schematic diagram of the overall structure of the lightless DC welding machine according to an embodiment of the present invention, a schematic diagram of the overall structure from another angle, a front view of the overall structure, and a top view of the overall structure.

[0043] The lightless DC welding machine of this invention includes:

[0044] A welding mechanism for clamping a workpiece for welding and feeding includes a first welding assembly for applying direct current to the workpiece, a second welding assembly horizontally disposed on one side of the first welding assembly, and a DC transformer 19 connected to the first welding assembly and the second welding assembly respectively for outputting direct current.

[0045] The linkage mechanism, which is connected to the welding mechanism, includes a left movable plate 10 disposed below the first welding assembly for supporting the workpiece, a right movable plate 9 disposed below the second welding assembly, a left eccentric shaft 20 connected to the left movable plate 10 for adjusting the eccentricity of the left movable plate 10, and a right eccentric shaft 21 connected to the right movable plate 9 for adjusting the eccentricity of the right movable plate 9.

[0046] The drive mechanism, which is connected to the linkage mechanism, includes several servo motors for generating driving torque to adjust the height of the welding mechanism and an upsetting cylinder 13 connected to the left moving plate 10 for driving the left moving plate and the right moving plate to move horizontally relative to each other.

[0047] The detection mechanism, which is connected to the welding mechanism, is used to detect the relative movement distance of the left and right moving plates and the upsetting pressure;

[0048] A control mechanism, connected to the welding mechanism, the linkage mechanism, and the drive mechanism, is used to control the current value of the DC power output from the DC transformer 19 during the welding process to weld the workpiece; to control the rotation angles of the first and second butt welding assemblies around the left eccentric shaft 20 and the right eccentric shaft 21, respectively, to clamp the workpiece; to control the upsetting cylinder 13 to drive the left moving plate 10 to move relative to the right moving plate 9 to upset the workpiece; and to control the servo motor to drive the linkage mechanism to adjust the heights of the left moving plate 10 and the right moving plate 9, respectively.

[0049] It is also used to adjust the holding time of the upsetting pressure according to the total energy input to the workpiece during welding, and to correct the target value of the upsetting displacement according to the rate of change of the upsetting pressure.

[0050] Specifically, it also includes a bed 11 for supporting the welding mechanism, linkage mechanism and testing mechanism.

[0051] Specifically, the drive mechanism also includes a left reducer 14 connected to the left pressure arm, a left lift 24 connected to the left reducer 14, a right reducer 22 connected to the right pressure arm, and a right lift 25 connected to the right reducer 22.

[0052] The left servo motor 15 is connected to the left reducer 14, and the right servo motor 23 is connected to the right reducer 22.

[0053] Specifically, the DC current output of DC transformer 19 has a range of (0, 200kA) and a voltage range of (0, 10V).

[0054] Specifically, the eccentric shaft is a shaft with an eccentric cam, and the adjustable range of the eccentricity is (0, 5 mm).

[0055] Specifically, the servo motor is an AC servo motor with a power of 7kW;

[0056] The pressure range of the top forging cylinder 13 is (0, 20 MPa).

[0057] Specifically, the control mechanism is an industrial computer.

[0058] Specifically, the process of adjusting the height of the welding mechanism is as follows: the servo motor above the equipment rotates, driving the eccentric shaft to rotate, and the pressure arm moves relative to the moving plate. By rotating the servo motor in both directions, the left and right pressure arms 4 can move away from and approach the left and right moving plates 9, respectively. The process of adjusting the height of the welding mechanism is as follows: the servo motor below the equipment rotates, the elevator drives the connecting rod 17 to rotate around the eccentric shaft, and the eccentric shaft causes the moving plate to change height, thereby adjusting the height of the left and right electrodes 7.

[0059] There are two lifting platforms on each side and one servo motor on each side, which are fixed to the rear side of the bed 11. The output shaft of the servo motor is connected to the input shaft of the lifting platform. The lifting shaft of the lifting platform is connected to the connecting rod 17 through the first rotating shaft 16. The other end of the connecting rod 17 is connected to the moving plate through the eccentric shaft.

[0060] Specifically, the upsetting process involves left and right moving plates 9 connected by connecting rod 17 and second rotating shaft 18. A bearing is installed between the second rotating shaft 18 and connecting rod 17, allowing relative rotation. The center of connecting rod 17 is connected to bed 11 via an intermediate rotating shaft, which is also connected to bed 11, allowing relative rotation. The cylinder body of upsetting cylinder 13 is mounted on left moving plate 10, and the piston rod of upsetting cylinder 13 is connected to right moving plate 9. When the piston rod of upsetting cylinder 13 retracts, the left and right moving plates move relative to each other. Due to the influence of the rear connecting rod 17, the relative movement distance of the left and right moving plates is equal, resulting in consistent consumption of welding joints on both sides of the workpiece and more stable welding quality.

[0061] In practice, the device of this invention, by setting up a welding mechanism, a linkage mechanism, a driving mechanism, a detection mechanism, and a control mechanism, achieves stable clamping of the workpiece, efficient DC heating welding, precise upsetting control, and dynamic parameter adjustment. It effectively overcomes the problems of unstable heat input, severe high-temperature metal spatter, and excessive oxidation fumes caused by the periodic changes in current direction in traditional AC butt welding machines, which lead to decreased welding quality. The use of a DC transformer 19 provides a stable unidirectional current to the first and second butt welding components, significantly improving the heat concentration and thermal efficiency of the welding area, reducing ineffective energy consumption and metal spatter, and suppressing the oxidation reaction rate, thereby improving weld formation quality and reducing subsequent cleaning costs. The DC voltage is stable, with fluctuations typically not exceeding ±1. The DC current is 0%, far lower than the fluctuation range of AC current. During the welding process, the positive and negative electrodes generate instantaneous high current and high temperature, directly melting the weld joint of the rim without spatter. The DC current direction is constant and there is no periodic change, so a constant amount of heat is generated during the welding process, ensuring stable welding quality. At the start of welding, high heat is generated instantaneously, melting the weld joint of the workpiece and completing the upsetting, without the need for preheating and melting, thus reducing workpiece loss. Because DC non-light welding can reach the upsetting state in about 1 second after the start of welding, the welding time is only about 2 seconds, about 1 / 5 of the welding time of conventional AC flash welding machines. The angle between the jaws and the electrodes is adjusted by a servo motor driving the cam mechanism, which can quickly complete the model change and improve production efficiency.

[0062] In practice, the device of the present invention achieves synchronous adjustment of the height of the left and right jaws 6 through the linkage structure of the eccentric shaft with the left moving plate 10 and the right moving plate 9 and the linkage mechanism driven by the servo motor. This solves the problem of misalignment of the upper and lower electrodes caused by differences in workpiece diameter or assembly deviation, avoids electrode burn-out and uneven heat distribution caused by excessive local contact resistance, and achieves flexible clamping of the workpiece by controlling the rotation angle of the first welding assembly and the second welding assembly around the eccentric shaft. This reduces the risk of mechanical damage to the workpiece surface during clamping and improves clamping stability and repeatability.

[0063] Specifically, the first welding assembly includes a left electrode 8 disposed above the left moving plate 10 and a left jaw 5 disposed above the left electrode 8 for fixing the workpiece.

[0064] The second welding assembly includes a right electrode 7 disposed above the right moving plate 9 and a right jaw 6 disposed above the right electrode 7 for applying a horizontal clamping force to the workpiece.

[0065] Specifically, the left electrode 8 and the right electrode 7 are made of copper alloy.

[0066] Specifically, the linkage mechanism also includes:

[0067] The left pressure arm 3 is positioned above the left jaw 5 and is used to apply a vertically downward clamping force to the workpiece.

[0068] The left clamping cylinder 1 is connected to the left clamping arm 3 and is used to drive the left clamping arm 3 to move.

[0069] The right pressure arm 4 is positioned above the right jaw 6 and is used to apply a vertically downward clamping force to the workpiece.

[0070] The right clamping cylinder 2 is connected to the right pressure arm 4 and is used to drive the right pressure arm 4 to move.

[0071] Specifically, the clamping action involves the extension of the piston rod of the clamping cylinder, which, through the pivot at the connection point with the clamping arm, drives the clamping arm and jaws to rotate around the eccentric axis towards the electrode until the workpiece is clamped. After welding is completed, the piston rod of the clamping cylinder retracts, and the clamping arm and jaws release the workpiece.

[0072] In practice, the device of the present invention drives the left and right moving plates to move relative to each other through the top forging cylinder, forming a bidirectional symmetrical force-applying clamping mechanism. This effectively balances the electromagnetic thrust and thermal expansion stress generated during the welding process, prevents the workpiece from axially shifting or deviating during the electric heating stage, ensures the uniformity of current flow through the interface and the stability of contact pressure, and further improves the controllability of the welding process and the consistency of joint quality.

[0073] Specifically, the testing institutions include:

[0074] Displacement sensor 12, which is connected to the top forging cylinder 13, is used to detect the relative movement distance between the left moving plate and the right moving plate;

[0075] A pressure sensor, which is connected to the upsetting cylinder 13, is used to detect the upsetting pressure.

[0076] Specifically, the displacement sensor 12 is a linear encoder mounted on the piston rod of the top cylinder; the pressure sensor is a piezoelectric sensor.

[0077] Specifically, the control mechanism is connected to the DC transformer 19 to obtain the total energy of the welding input workpiece. If the total energy is less than or equal to the preset energy, the holding time of the upsetting pressure is increased.

[0078] Specifically, the holding time of the upsetting pressure is the difference between the moment when the left clamping cylinder cancels the clamping force applied to the workpiece and the moment when welding ends.

[0079] Specifically, the total energy is the product of the current and output voltage output by the DC transformer 19 during the duration of the welding current, and the duration of the welding current.

[0080] Specifically, under the conditions that the DC current output by the DC transformer 19 is in the range of (0, 200kJ], the output voltage is in the range of (0, 10V], and the control mechanism collects current and voltage signals at a sampling frequency of 100Hz, the general range of the preset energy is [100kJ, 500kJ], and the preferred embodiment of the preset energy is 150kJ.

[0081] Those skilled in the art will understand that the selectable range of preset energy and the preferred embodiment provided in this embodiment are the values ​​that best address the technical problem solved by the present invention, under the conditions that the DC current output of the DC transformer 19 is in the range of (0, 200KA), the output voltage is in the range of (0, 10V), and the control mechanism collects current and voltage signals at a sampling frequency of 100Hz. In actual applications or experiments, those skilled in the art can make adaptive adjustments to the preset energy according to the actual application environment and application scenario.

[0082] In practice, if the difference between the preset energy and the total energy exceeds 1kJ, the holding time of the upsetting pressure will increase by 0.5s. For example, if the default holding time of the upsetting pressure is 3s and the total energy is 130kJ, the holding time will increase to 3s + 0.5s × 2 = 4s.

[0083] In practice, the device of the present invention adjusts the holding time of the upsetting pressure according to the total energy input to the workpiece through the control mechanism. Since the plastic deformation capacity of the fusion zone is insufficient under low energy input conditions, releasing the upsetting pressure too early will lead to insufficient weld joint strength or microcracks. By establishing a negative feedback relationship between total energy and holding time, the upsetting pressure holding time is automatically extended when the total energy is less than or equal to the preset energy. This ensures that the fusion zone completes the full recrystallization and densification process under high pressure, enhances the metallurgical bonding strength of the weld joint, avoids defects such as incomplete welding and incomplete penetration, and improves welding reliability.

[0084] Specifically, the control mechanism is connected to the pressure sensor to obtain the rate of change of the upsetting pressure. Under the condition that the rate of change is greater than or equal to the preset rate of change, a displacement compensation amount is added to the effective displacement as the base value, and this compensation amount is used as the corrected target value of the upsetting displacement.

[0085] Specifically, the effective displacement is the current relative movement distance under the condition that the rate of change is equal to the preset rate of change.

[0086] Specifically, the rate of change of the upsetting pressure is the ratio of the difference between the upsetting pressure at the end of the unit detection time and the upsetting pressure at the beginning of the unit detection time during the upsetting process of the left moving plate 10 to the unit detection time.

[0087] Specifically, the unit detection time is 1 second.

[0088] Specifically, under the conditions that the DC current output by the DC transformer 19 is in the range of (0, 200KA) and the output voltage is in the range of (0, 10V), and the control mechanism collects current and voltage signals at a sampling frequency of 100Hz, the general range of the preset rate of change is [4MPa / s, 8MPa / s], and the preferred embodiment of the preset rate of change is 5MPa / s.

[0089] Those skilled in the art will understand that the selectable range of the preset rate of change and the preferred embodiment provided in this embodiment are the values ​​that best address the technical problem solved by the present invention, under the conditions that the DC current output by the DC transformer 19 is in the range of (0, 200kA), the output voltage is in the range of (0, 10V), and the control mechanism collects current and voltage signals at a sampling frequency of 100Hz. In actual applications or experiments, those skilled in the art can make adaptive adjustments to the preset rate of change according to the actual application environment and application scenario.

[0090] In practice, for example, if the pressure increases from 8MPa to 12MPa within a unit detection time of 1 second, the rate of change is 4MPa / s, and the current effective displacement is 4mm, then the upsetting continues with 4mm as the target. If the difference between the rate of change and the preset rate of change exceeds 1MPa / s, the additional value of the displacement compensation increases by 0.1mm. For example, if the rate of change is 7MPa / s and the current effective displacement is 2.2mm, then the additional displacement compensation is 0.1mm × 2 = 0.2mm. The corrected upsetting displacement target value based on the effective displacement plus the additional displacement compensation is 2.2mm + 0.2mm = 2.4mm.

[0091] In practice, the device of the present invention collects the relative movement distance and upsetting pressure of the left moving plate 10 through the detection mechanism, and the control mechanism dynamically corrects the upsetting displacement target value based on the rate of change of upsetting pressure. Due to factors such as workpiece material hardness fluctuation, cylinder response lag or mechanical wear, the actual upsetting force may deviate from the set value, which may lead to upsetting displacement control failure, resulting in problems such as excessive flash, joint misalignment or local overheating. By introducing the pressure change rate as the basis for compensation, when the change rate is greater than or equal to the preset change rate, the displacement compensation amount is superimposed on the effective displacement to achieve adaptive adjustment of the upsetting stroke, thereby improving the welding consistency of different batches of workpieces under non-ideal conditions.

[0092] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A non-light DC welding machine, characterized in that, include: A welding mechanism for clamping a workpiece for welding and feeding includes a first welding assembly for applying direct current to the workpiece, a second welding assembly horizontally disposed on one side of the first welding assembly, and a DC transformer connected to the first welding assembly and the second welding assembly respectively for outputting direct current. The linkage mechanism, which is connected to the welding mechanism, includes a left movable plate disposed below the first welding assembly for supporting the workpiece, a right movable plate disposed below the second welding assembly, a left eccentric shaft connected to the left movable plate for adjusting the eccentricity of the left movable plate, and a right eccentric shaft connected to the right movable plate for adjusting the eccentricity of the right movable plate. The drive mechanism, which is connected to the linkage mechanism, includes several servo motors for generating driving torque to adjust the height of the welding mechanism and an upsetting cylinder connected to the left moving plate for driving the left moving plate and the right moving plate to move horizontally relative to each other. The detection mechanism, which is connected to the welding mechanism, is used to detect the relative movement distance of the left and right moving plates and the upsetting pressure; A control mechanism, connected to the welding mechanism, the linkage mechanism, and the drive mechanism, is used to control the current value of the DC power output from the DC transformer during the welding process to weld the workpiece; to control the rotation angles of the first and second welding assemblies around the left and right eccentric axes respectively to clamp the workpiece; to control the upsetting cylinder to drive the left moving plate to move relative to the right moving plate to upset the workpiece; and to control the servo motor to drive the linkage mechanism to adjust the heights of the left and right moving plates respectively. It is also used to adjust the holding time of the upsetting pressure according to the total energy input to the workpiece during welding, and to correct the target value of the upsetting displacement according to the rate of change of the upsetting pressure.

2. The non-light DC welding machine according to claim 1, characterized in that, The first welding assembly includes a left electrode disposed above the left moving plate and a left jaw disposed above the left electrode for fixing the workpiece; The second welding assembly includes a right electrode disposed above the right moving plate and a right jaw disposed above the right electrode for applying a horizontal clamping force to the workpiece.

3. The non-light DC welding machine according to claim 2, characterized in that, The linkage mechanism also includes: The left pressure arm, which is positioned above the left jaw, is used to apply a vertically downward clamping force to the workpiece; A left clamping cylinder is connected to the left pressure arm and is used to drive the left pressure arm to move; The right pressure arm is positioned above the right jaw and is used to apply a vertically downward clamping force to the workpiece. The right clamping cylinder is connected to the right clamping arm and is used to drive the right clamping arm to move.

4. The non-light DC welding machine according to claim 3, characterized in that, The testing institutions include: A displacement sensor, connected to the upsetting cylinder, is used to detect the relative movement distance between the left moving plate and the right moving plate; A pressure sensor, connected to the upsetting cylinder, is used to detect the upsetting pressure.

5. The non-light DC welding machine according to claim 4, characterized in that, The control mechanism is connected to the DC transformer to obtain the total energy of the welding input workpiece. If the total energy is less than or equal to the preset energy, the holding time of the upsetting pressure is increased.

6. The non-light DC welding machine according to claim 5, characterized in that, The duration of holding the upsetting pressure is the difference between the moment when the left clamping cylinder cancels the clamping force applied to the workpiece and the moment when welding ends.

7. The non-light DC welding machine according to claim 6, characterized in that, The total energy is the product of the current and voltage output by the DC transformer during the duration of the welding current, and the duration of the welding current.

8. The non-light DC welding machine according to claim 7, characterized in that, The control mechanism is connected to the pressure sensor to obtain the rate of change of the upsetting pressure. Under the condition that the rate of change is greater than or equal to the preset rate of change, a displacement compensation amount is added to the effective displacement as the base value, and this compensation amount is used as the corrected target value of the upsetting displacement.

9. The non-light DC welding machine according to claim 8, characterized in that, The effective displacement is the current relative movement distance under the condition that the rate of change is equal to the preset rate of change.

10. The non-light DC welding machine according to claim 9, characterized in that, The rate of change of the upsetting pressure is the ratio of the difference between the upsetting pressure at the end of the unit detection time and the upsetting pressure at the beginning of the unit detection time during the upsetting process of the left moving plate to the unit detection time.

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