Flash butt welding machine control system for titanium alloy bar welding and using method of flash butt welding machine control system

Abstract

The invention belongs to the technical field of non-ferrous metal processing equipment, and particularly discloses a control system of a flash butt welder for titanium alloy bar welding and a using method of the control system. The control system comprises a human-computer interface which is connected with a welding heat control unit and a mechanism action control unit through a PLC; welding operation of the titanium alloy bar is achieved through cooperative linkage of the two parts; wherein the welding heat control unit is divided into a flash establishing stage P1, a stable heating stage P2 and a stamping welding stage P3, current and duration of each stage can be set on a human-computer interface, and heat is controlled through a silicon controlled rectifier control circuit board and two anti-parallel thyristors; the mechanism action control unit comprises a bar clamping air cylinder and other components, and all the components are connected with the PLC. Heat can be accurately controlled, the butt welding success rate and the welding seam quality are improved, equipment runs in a programmed mode, safety and reliability are achieved, and an efficient, stable and safe solution is provided for welding of titanium alloy bars of different specifications.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metal processing equipment, and in particular relates to a flash butt welding machine control system for titanium alloy bar welding and a use method thereof. Background Art

[0002] As we all know, titanium alloy materials have been widely used in many fields such as aerospace, marine engineering, and medical devices due to their high strength, low density, excellent corrosion resistance, and biocompatibility. In the production process of titanium alloy products, the welding of bars is a key link, and its welding quality directly affects the performance and reliability of the final product.

[0003] Among them, the flash butt welding machine is widely used for longitudinal connection of bars. Its working principle is to use the bars of the electrodes at both ends of the butt welding machine to contact each other, pass low voltage and high current, and after the bars are heated to a certain temperature and softened, axial pressure forging is performed to form a butt welding joint. It has the advantages of fast welding speed and relatively simple welding process. However, our company has found in long-term use that the traditional flash butt welding machine has poor welding effect on titanium alloy bars, especially the low success rate of welding titanium alloys of different specifications. The reasons are as follows:

[0004] First, the heat control is not precise: during the welding process, it is difficult for traditional flash butt welding machines to accurately control the welding heat according to the special physical and chemical properties of titanium alloy bars. Titanium alloys have high melting points, low thermal conductivity, and strong chemical activity, and the heat input requirements during the welding process are relatively stringent. When welding titanium alloy bars of different specifications, it is necessary to accurately adjust the heat at each stage of welding (such as flash establishment, stable heating, and stamping welding stages), but traditional welding machines lack effective means to achieve this precise heat control, which makes it easy for the weld joint to overheat or lack of heat, thereby affecting the quality of the weld, such as coarse grains, lack of fusion, pores, cracks and other defects in the weld, which reduces the success rate of butt welding of titanium alloy bars;

[0005] Second, the equipment is less safe: the mechanism and motion control of traditional flash welding machines is relatively simple, and there are safety hazards in the welding process, such as bar clamping, electrode clamp feeding, and protection of the welding area. For example, when clamping materials, due to the lack of effective protection and precise control, operators are prone to accidental touch, causing burns or mechanical injuries; during the welding process, the operating state of the equipment is unstable, and it is easy to cause equipment failure due to unexpected circumstances, which not only affects production efficiency, but may also cause more serious safety accidents, increasing the production risks and costs of enterprises.

[0006] The third is inconvenient operation and lack of flexibility: the operating interface and control system of traditional welding machines are not intelligent enough, and it is impossible to quickly and accurately set welding parameters according to different specifications of titanium alloy bars. Operators need to rely on experience and multiple tests to adjust welding current, time and other parameters, which not only consumes time and energy, but also makes it difficult to ensure the consistency and stability of each welding. At the same time, during the welding process, it is impossible to monitor key parameters such as temperature and current in the welding area in real time, making it difficult to adjust and optimize the welding process in a timely manner, and unable to meet the needs of modern industrial production for efficient and high-quality welding.

[0007] In summary, these problems existing in the existing flash butt welding machine in titanium alloy bar welding have seriously restricted the wide application and further development of titanium alloy materials in various fields. Therefore, there is an urgent need for a new flash butt welding machine control system specifically for titanium alloy bar welding to solve these problems.

[0008] In view of this, this invention is proposed. Summary of the invention

[0009] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a flash butt welding machine control system for titanium alloy bar welding and a method of using the same, which are mainly used to solve the problems of inaccurate heat control, low equipment safety, inconvenient operation and lack of flexibility of traditional flash butt welding machines, which lead to poor welding quality of titanium alloy bars of different specifications, low production efficiency and frequent safety accidents.

[0010] The purpose of the present invention is to be solved by the following technical solutions:

[0011] In a first aspect, the present invention provides a flash butt welding machine control system for titanium alloy bar welding, comprising a human-machine interface, wherein the human-machine interface is respectively connected to a welding heat control unit and a mechanism motion control unit through a PLC controller, and the welding heat control unit and the mechanism motion control unit are coordinated and linked through the PLC controller to perform welding operations on titanium alloy bars;

[0012] Among them, the welding heat control unit is divided into the following three stages when controlling heat: the first stage is the flash establishment stage P1, the second stage is the stable heating stage P2, and the third stage is the stamping welding stage P3. The durations corresponding to the three stages P1, P2, and P3 are T1, T2, and T3, respectively, and the current size and duration of each stage are set through the human-machine interface.

[0013] Furthermore, the welding heat control unit includes a thyristor control circuit board, a first thyristor and a second thyristor, the first thyristor and the second thyristor are respectively connected to the thyristor control circuit board, the thyristor control circuit board is connected to the PLC controller, and the thyristor control circuit board outputs a continuous analog signal to adjust the conduction angle of the first thyristor and the second thyristor according to the control command signal of the PLC controller, so as to control the current size in each stage during welding.

[0014] Furthermore, the first thyristor and the second thyristor are connected in anti-parallel.

[0015] Furthermore, the thyristor control circuit board is a PAC16P single-phase phase-shift voltage regulator board.

[0016] Furthermore, the first thyristor and the second thyristor both adopt a flat plate structure, and their model is KP500A, 1600V.

[0017] Furthermore, the mechanism action control unit includes a bar clamping cylinder, an electrode clamp and a feeding cylinder;

[0018] Among them, the electrode clamp and the feeding cylinder are both arranged on the base, the rod clamping cylinder is arranged directly above the electrode clamp, and is used to provide clamping force to the titanium alloy rod located on the electrode clamp. The feeding cylinder is located on one side of the electrode clamp, and the piston rod end of the feeding cylinder is fixedly connected to the side wall of the electrode clamp. The feeding cylinder is used to control the feed of the electrode clamp during welding.

[0019] Furthermore, the mechanism action control unit also includes a welding guard plate and a limit switch arranged on the base, and the limit switch is used to detect the position of the welding guard plate.

[0020] Furthermore, the bar clamping cylinder, electrode clamp, feeding cylinder, welding guard plate and limit switch are all connected to the PLC controller.

[0021] Furthermore, the human-machine interface is mainly composed of a parameter setting area, an action start and stop button, a heating current monitoring part, a welding area temperature detection part and an over-temperature alarm part. The current size and duration of each stage are set through the parameter setting area of ​​the human-machine interface.

[0022] In a second aspect, the present invention provides a method for using the control system of the flash butt welding machine for titanium alloy bar welding, the method comprising the following steps:

[0023] Step 1, parameter setting: according to the specifications of the titanium alloy bar to be welded, determine the heat required for each stage, and then set the current size and duration of each stage in the human-machine interface according to the heat required for each stage;

[0024] Step 2, clamping the material: after step 1) is completed, the welding guard plate of the mechanism action control unit is opened through the PLC controller, the titanium alloy bar to be welded is placed in the material clamping area, and the bar clamping cylinder of the mechanism action control unit is controlled to extend, so that the electrode clamp clamps the titanium alloy bar, and then the welding guard plate is closed. After the limit switch of the mechanism action control unit detects that the welding guard plate is closed in place;

[0025] Step 3, welding: after step 2) is completed, the PLC controller controls the welding heat control unit to make the first thyristor and the second thyristor start to ignite and discharge, enter the flash establishment stage P1, and heat the bar welding part according to the set current. After the P1 stage duration T1 ends; the PLC controller controls the feeding cylinder of the mechanism action control unit to uniformly control the electrode clamp feeding, and makes the first thyristor and the second thyristor discharge according to the current set in the stable heating stage P2. When the P2 section duration T2 ends; the feeding cylinder arrives at the stamping welding area, and the PLC controller controls the first thyristor and the second thyristor to discharge according to the current set in the stamping welding stage P3, and the feeding cylinder continues to move forward evenly. When the P3 section duration T3 ends, the forging and welding operation is completed; at this time, the PLC controller controls to open the welding guard plate, and reset the bar clamping cylinder and the feeding cylinder, and the entire welding process ends.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The flash butt welding machine control system provided by the present invention is mainly composed of a human-machine interface, a PLC controller, a welding heat control unit and a mechanism motion control unit, and the welding heat control unit and the mechanism motion control unit are both coordinated and linked through the PLC controller to execute the welding indicators input by the human-machine interface. Among them, the welding heat control unit can accurately and stably control the heat of the three stages (flash establishment stage P1, stable heating stage P2, stamping welding stage P3) during the butt welding of titanium alloy bars of different specifications through the thyristor control circuit board and two anti-parallel thyristor elements. It has successfully overcome the problem that traditional flash butt welding machines are difficult to adapt to the welding of titanium alloy bars of different specifications, greatly improved the success rate of butt welding of titanium alloy bars, especially the weld quality has been significantly improved, laying a good foundation for subsequent processing; at the same time, the control system improves the safety of the equipment in many aspects. It not only eliminates the safety hazards caused by accidental touch and misoperation from the source through the precise control of welding guard plates, bar clamping cylinders, feeding cylinders and other mechanisms, but also effectively reduces equipment failures and the losses caused by them on the basis of ensuring production safety. It has played a key role in improving welding quality and ensuring production safety, and has brought efficient, stable and safe new solutions to the welding production of titanium alloy bars. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, serve to explain the principles of the present invention.

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 It is a schematic diagram of the control system composition of the flash butt welding machine for titanium alloy bar welding of the present invention;

[0031] Figure 2 It is a schematic diagram of the structure of the mechanism action control unit in the control system of the present invention;

[0032] Figure 3 It is a flow chart of the method for using the flash butt welding machine control system of the present invention.

[0033] in:

[0034] 1 is the human-machine interface;

[0035] 2 is the PLC controller;

[0036] 3 is a welding heat control unit; 31 is a thyristor control circuit board; 32 is a first thyristor; 33 is a second thyristor;

[0037] 4 is a mechanism motion control unit; 41 is a bar clamping cylinder; 42 is an electrode clamp; 43 is a feeding cylinder; 44 is a welding guard plate; 45 is a limit switch. DETAILED DESCRIPTION

[0038] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices consistent with some aspects of the present invention as detailed in the appended claims.

[0039] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below with reference to the accompanying drawings.

[0040] See also Figures 1-2The flash butt welding machine control system for titanium alloy bar welding provided in the embodiment of the present invention comprises a human-machine interface 1, which is respectively connected to a welding heat control unit 3 and a mechanism motion control unit 4 through a PLC controller 2. In the actual operation process, the welding heat control unit 3 and the mechanism motion control unit 4 realize a highly coordinated linkage operation mechanism under the precise control of the PLC controller 2, which can accurately and efficiently execute various instructions, thereby realizing the welding operation of titanium alloy bars A of different specifications.

[0041] In the embodiment of the present invention, the human-machine interface 1 is mainly composed of a parameter setting area, an action start / stop button, a heating current monitoring part, a welding area temperature detection part and an over-temperature alarm part.

[0042] Specifically, in the embodiment of the present invention, the welding heat control unit 3 is the core of the entire control system, and it is divided into the following three stages when controlling heat: the first stage is the flash establishment stage P1, which mainly realizes rapid heating of the weldment by applying a relatively large current to the bar for a short time, forming a spark torrent-flash, thereby establishing a weldment heating circuit; the second stage is the stable heating stage P2, which mainly realizes heating of the bar by continuously applying a relatively small current to the bar for a long time, so that the temperature of the bar in this area reaches the specified welding temperature; the third stage is the stamping welding stage P3, which mainly realizes welding function by applying a relatively large current to the bar for a short time so that the bar is squeezed against each other in the case of top forging; in addition, the duration corresponding to these three stages P1, P2, and P3 is set as T1, T2, and T3 respectively. It is worth noting that in the entire welding process, the current size and duration required for each stage can be accurately set through the parameter setting area of ​​the human-machine interface 1. Since in the actual welding scene, the voltage is usually kept constant, according to Joule's law (Q=I 2 RT, where Q represents heat, I represents current, R represents resistance, and T represents time). Under the condition of constant resistance and voltage, by precisely controlling the current and duration of each stage, the total amount of heat released in each stage can be effectively controlled, thereby achieving refined and precise control of the welding process, ensuring that the welding quality meets the expected standards and meets the stringent requirements for heat in welding titanium alloy bars of different specifications.

[0043] In an embodiment of the present invention, the welding heat control unit 3 includes a thyristor control circuit board 31, a first thyristor 32 and a second thyristor 33. The first thyristor 32 and the second thyristor 33 are respectively connected to the thyristor control circuit board 31, and the thyristor control circuit board 31 is connected to the PLC controller 2. The thyristor control circuit board 31 outputs a continuous analog signal to adjust the conduction angle of the first thyristor 32 and the second thyristor 33 according to the control command signal of the PLC controller 2, so as to control the current size in each stage during welding.

[0044] Specifically, the first thyristor 32 and the second thyristor 33 both adopt a flat plate structure, and the model is KP500A, 1600V. The selection of this model is based on a comprehensive consideration of the current carrying capacity and voltage stability during the welding process. It is particularly critical that the first thyristor 32 and the second thyristor 33 are connected in anti-parallel. After this connection, when the system is running, by adjusting the conduction angle of each thyristor, it is possible to accurately adjust the size of the welding current, and then form a complete and accurate heat control system based on the pre-set duration of each stage. In this way, the welding heat control unit 3 can stably and accurately output heat that is compatible with the titanium alloy bar welding process requirements in the flash establishment stage P1, the stable heating stage P2, and the stamping welding stage P3, which fundamentally guarantees the quality of titanium alloy bar welding.

[0045] Among them, the thyristor control circuit board 31 uses a PAC16P single-phase phase-shifting voltage regulator board, which can output a continuous analog signal. The signal directly acts on the thyristor to accurately adjust the conduction angle of the thyristor, thereby realizing accurate control of the welding current of the welding machine. In addition, the trigger pulse analog signal output by the thyristor control circuit board 31 has extremely high symmetry and stability, and does not change with the ambient temperature. There is no need to adjust the pulse symmetry and limit during use. At the same time, it also has a complete multi-channel protection system such as overcurrent, overvoltage, current limiting, and voltage limiting. Once a fault occurs, the protection system can act in a short time to reliably protect the thyristor.

[0046] In the embodiment of the present invention, the PLC controller 2 should be able to output a 4-20 mA analog current signal, thereby achieving stable control of the trigger circuit of the thyristor control circuit board 31 .

[0047] In the embodiment of the present invention, the mechanism action control unit 4 is as follows Figure 2As shown, it includes a bar clamping cylinder 41, an electrode clamp 42 and a feeding cylinder 43. Among them, the electrode clamp 42 and the feeding cylinder 43 are both arranged on the base, and the electrode clamp 42 is arranged to slide in the horizontal direction. The bar clamping cylinder 41 is arranged just above the initial position of the electrode clamp 42, and is used to provide clamping force to the titanium alloy bar A located on the electrode clamp 42. The feeding cylinder 43 is located on one side of the electrode clamp 42, and the end of the piston rod of the feeding cylinder 43 is fixedly connected to the side wall of the electrode clamp 42. During the welding process, the feeding cylinder 43 plays the role of controlling the feeding of the electrode clamp 2. By controlling the extension and contraction of the piston rod, the position of the electrode clamp 42 can be adjusted.

[0048] Furthermore, the mechanism motion control unit 4 also includes a welding guard plate 44 and a limit switch 45. The welding guard plate 44 plays a role of physical protection to prevent sparks, heat and other potential dangerous factors in the welding process from causing harm to the operator, while the limit switch 45 is used to detect the position state of the welding guard plate 44 in real time and accurately. Only when the limit switch 45 detects that the welding guard plate 44 is in a closed state, the entire system will allow the heating welding operation to be performed, which eliminates the safety hazards caused by misoperation or unexpected situations from the source, and effectively guarantees the safety of the production process. In addition, the bar clamping cylinder 41, the electrode clamp 42, the feeding cylinder 43, the welding guard plate 44 and the limit switch 45 are all connected to the PLC controller 2, so that the PLC controller 2 can coordinately control these components, ensuring that the entire mechanism motion control unit 4 can operate stably according to the preset program and parameters, providing reliable protection for the welding operation of titanium alloy bars, and greatly improving the automation and precision control capabilities of the welding process.

[0049] In addition, if Figure 3 As shown, the present invention also provides a method for using a control system of a flash butt welding machine for titanium alloy bar welding, and the specific process is as follows:

[0050] 1) Parameter setting: Determine the heat required for each stage according to the specifications of the titanium alloy bar A to be welded, and then set the current size and duration of each stage in the human-machine interface 1 according to the heat required for each stage;

[0051] 2) Clamping materials: After step 1) is completed, the welding guard plate 44 is controlled by the PLC controller 2 to place the titanium alloy bar A to be welded in the material clamping area, and the bar clamping cylinder 41 is controlled to extend so that the electrode clamp 42 clamps the titanium alloy bar A, and then the welding guard plate 44 is closed. When the limit switch 45 detects that the welding guard plate 44 is closed in place;

[0052] 3) Welding: After step 2) is completed, the PLC controller 2 controls the thyristor control circuit board 31 to make the first thyristor 32 and the second thyristor 33 start to ignite and discharge, enter the flash establishment stage P1, and quickly heat the welding part of the rod according to the set current. After the P1 stage duration T1 ends; the PLC controller 2 controls the feeding cylinder 43 to uniformly control the feeding of the electrode clamp 42 to make the welding part close, and make the first thyristor 32 and the second thyristor 33 discharge according to the current set in the stable heating stage P2. When the P2 section duration T2 ends; the feeding cylinder 43 arrives at the stamping welding area, the PLC controller 2 controls the thyristor control circuit board 31 to make the first thyristor 32 and the second thyristor 33 discharge according to the current set in the stamping welding stage P3, and the feeding cylinder 43 continues to move forward evenly. When the P3 section duration T3 ends, the forging and welding operation is completed; at this time, the PLC controller 2 controls to open the welding guard plate 44, and resets the rod clamping cylinder 41 and the feeding cylinder 43, and the entire welding process ends.

[0053] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0054] It should be understood that the present invention is not limited to what has been described above and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A flash butt welding machine control system for titanium alloy bar welding, characterized in that: The invention comprises a human-machine interface (1), wherein the human-machine interface (1) is respectively connected to a welding heat control unit (3) and a mechanism action control unit (4) via a PLC controller (2), and the welding heat control unit (3) and the mechanism action control unit (4) are coordinated and linked via the PLC controller (2) to perform welding operations on a titanium alloy bar (A); The welding heat control unit (3) is divided into the following three stages when controlling heat: the first stage is the flash establishment stage P1, the second stage is the stable heating stage P2, and the third stage is the stamping welding stage P3. The durations corresponding to the three stages P1, P2, and P3 are T1, T2, and T3, respectively, and the current size and duration of each stage are set through the human-machine interface (1).

2. The flash butt welding machine control system for titanium alloy bar welding according to claim 1 is characterized in that: The welding heat control unit (3) comprises a thyristor control circuit board (31), a first thyristor (32) and a second thyristor (33); the first thyristor (32) and the second thyristor (33) are respectively connected to the thyristor control circuit board (31); the thyristor control circuit board (31) is connected to a PLC controller (2); the thyristor control circuit board (31) outputs a continuous analog signal to adjust the conduction angle of the first thyristor (32) and the second thyristor (33) according to a control command signal of the PLC controller (2), so as to control the current size at each stage during welding.

3. The flash butt welding machine control system for titanium alloy bar welding according to claim 2 is characterized in that: The first thyristor (32) and the second thyristor (33) are connected in anti-parallel.

4. The flash butt welding machine control system for titanium alloy bar welding according to claim 2 is characterized in that: The thyristor control circuit board (31) is a PAC16P single-phase phase-shift voltage regulator board.

5. The flash butt welding machine control system for titanium alloy bar welding according to claim 2 is characterized in that: The first thyristor (32) and the second thyristor (33) both adopt a flat plate structure, and their model is KP500A, 1600V.

6. The flash butt welding machine control system for titanium alloy bar welding according to claim 1 is characterized in that: The mechanism action control unit (4) comprises a bar clamping cylinder (41), an electrode clamp (42) and a feeding cylinder (43); The electrode clamp (42) and the feeding cylinder (43) are both arranged on the base, the bar clamping cylinder (41) is arranged directly above the electrode clamp (42) and is used to provide a clamping force to the titanium alloy bar (A) located on the electrode clamp (42), the feeding cylinder (43) is located on one side of the electrode clamp (42), the piston rod end of the feeding cylinder (43) is fixedly connected to the side wall of the electrode clamp (42), and the feeding cylinder (43) is used to control the feeding of the electrode clamp (42) during welding.

7. The flash butt welding machine control system for titanium alloy bar welding according to claim 6 is characterized in that: The mechanism action control unit (4) also includes a welding guard plate (44) and a limit switch (45) arranged on the base, wherein the limit switch (45) is used to detect the position of the welding guard plate (44).

8. The flash butt welding machine control system for titanium alloy bar welding according to claim 7 is characterized in that: The bar material clamping cylinder (41), the electrode clamp (42), the feeding oil cylinder (43), the welding guard plate (44) and the limit switch (45) are all connected to the PLC controller (2).

9. The flash butt welding machine control system for titanium alloy bar welding according to claim 1, characterized in that: The human-machine interface (1) is mainly composed of a parameter setting area, an action start / stop button, a heating current monitoring part, a welding area temperature detection part and an over-temperature alarm part. The current magnitude and duration of each stage are set through the parameter setting area of ​​the human-machine interface (1).

10. A method for using the control system of the flash butt welding machine for titanium alloy bar welding according to any one of claims 1 to 9, characterized in that: The method of use comprises the following steps: Step 1, parameter setting: according to the specifications of the titanium alloy bar (A) to be welded, determine the heat required for each stage, and then set the current and duration of each stage on the human-machine interface (1) according to the heat required for each stage; Step 2, clamping the material: after step 1) is completed, the welding guard plate (44) of the mechanism action control unit (4) is controlled to open through the PLC controller (2), the titanium alloy bar (A) to be welded is placed in the material clamping area, and the bar clamping cylinder (41) of the mechanism action control unit (4) is controlled to extend, so that the electrode clamp (42) clamps the titanium alloy bar (A), and then the welding guard plate (44) is closed. After the limit switch (45) of the mechanism action control unit (4) detects that the welding guard plate (44) is closed in place; Step 3, welding: after step 2) is completed, the PLC controller (2) controls the welding heat control unit (3) to start the first thyristor (32) and the second thyristor (33) to ignite and discharge, enter the flash establishment stage P1, heat the welding part of the bar material according to the set current, and after the P1 stage duration T1 ends; the PLC controller (2) controls the feeding cylinder (43) of the mechanism action control unit (4) to uniformly control the feeding of the electrode clamp (42), and makes the first thyristor (32) and the second thyristor (33) start to ignite and discharge according to the stable heating stage The current set in P2 is discharged. When the duration T2 of the P2 section ends, the feeding cylinder (43) arrives at the stamping welding area. The PLC controller (2) controls the first thyristor (32) and the second thyristor (33) to discharge according to the current set in the stamping welding stage P3. The feeding cylinder (43) continues to move forward evenly. When the duration T3 of the P3 section ends, the forging and welding operation is completed. At this time, the PLC controller (2) controls the opening of the welding guard plate (44), and resets the bar clamping cylinder (41) and the feeding cylinder (43). The entire welding process ends.

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