Tungsten needle precision control device and method for invar alloy TIG oscillation welding

Abstract

The present application relates to a tungsten needle precision control device for Invar alloy TIG oscillation welding, comprising a TIG welding unit and a monitoring unit connected with a PLC control cabinet respectively; the monitoring unit is located beside the TIG welding unit, and can monitor the position of the tungsten needle, the dry elongation, and the welding arc length information in real time, and feed back the monitored information to the PLC control cabinet; the PLC control cabinet can control the TIG welding unit to realize the precise control of the position and pose of the tungsten needle, and control the alignment of the welding wire with the tungsten needle according to the information fed back by the monitoring unit; the TIG welding unit comprises a welding gun, a first hydraulic device, and a second hydraulic device; the first hydraulic device is internally provided with a tungsten needle; a clamping head, a slide rail, a lead screw, and a special motor are sleeved in the middle section of the welding gun, and a wire feeding head is clamped on the special motor. The hydraulic device, the special motor, and the monitoring unit can precisely control the position and pose of the tungsten needle during the TIG oscillation welding process, so as to control the welding quality.

Description

Technical Field

[0001] This invention belongs to the field of Invar alloy welding technology, and particularly relates to a tungsten needle precision control device and method for Invar alloy TIG oscillating welding. Background Technology

[0002] Since its discovery by foreign scientists in the 19th century, Invar alloys have been highly valued for their extremely low coefficient of thermal expansion. Due to their coefficient of thermal expansion being remarkably similar to that of composite materials, they are widely used as crucial materials for large composite mold structures in the aerospace field. However, due to the material's unique properties, its production technology faces high barriers to entry, particularly for high-end applications, and its production technology has long been monopolized by foreign countries. Therefore, the domestic production of Invar alloys has become one of the important directions for my country's research and development of key materials.

[0003] Currently, a small number of domestic enterprises have achieved small-batch domestic production of Invar alloys. However, compared with foreign Invar alloys, domestically produced Invar alloys suffer from problems such as large welding deformation and poor weld deposition during welding. TIG welding is a physically complex process. Extensive research has been conducted both domestically and internationally on TIG welding of thick Invar alloys. Problems such as large welding deformation and poor weld quality can only be addressed by mechanically constrained TIG oscillation welding. However, this method leads to increased stress and fails to solve the problem of poor weld deposition.

[0004] To address the aforementioned issues, Chinese patent CN113787280B discloses a method for manufacturing TIG welding wire to improve surface cleanliness, thereby enhancing TIG welding quality by improving the surface cleanliness of the welding wire. Chinese patent CN112388111A discloses a TIG welding wire control method, a TIG welding wire control system, equipment, and medium, which delivers the welding wire via a refeed method to achieve droplet transfer during the TIG welding process. However, these patents do not address the problems encountered in the oscillating welding of Invar alloys using TIG welding.

[0005] Therefore, there is an urgent need for a device and method for precise control of tungsten needles in TIG oscillating welding of Invar alloys. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a precise control device for tungsten needles in TIG oscillating welding of Invar alloys. The device uses a hydraulic system, a special-type motor, and a monitoring unit to precisely control the position and posture of the tungsten needles during the TIG oscillating welding process, thereby achieving the goal of controlling welding quality.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A precise control device for tungsten needle in TIG oscillating welding of Invar alloy includes a TIG welding unit and a monitoring unit respectively connected to a PLC control cabinet. The monitoring unit is located next to the TIG welding unit and is used to monitor the position, extension, and welding arc length of the tungsten needle in real time, and feed the monitored information back to the PLC control cabinet. The PLC control cabinet controls the TIG welding unit to achieve precise control of the tungsten needle's posture and to control the welding wire to align with the tungsten needle based on the information fed back by the monitoring unit.

[0009] The TIG welding unit includes a welding torch, with a first hydraulic device at the top center of the welding torch, one end of which extends into the welding torch, and a second hydraulic device disposed on both sides of the first hydraulic device and capable of swinging left and right; a tungsten needle with one end extending out of the bottom of the welding torch is inserted into the first hydraulic device.

[0010] A clamping head is fitted in the middle section of the welding torch. A slide rail is provided on one side of the clamping head. A lead screw extending downward is provided at the top of the slide rail. A special type motor is fitted on the lead screw. When the special type motor is working, it can slide up and down along the lead screw. A wire feeding head with one end extending to the side of the tungsten needle is clamped on the special type motor.

[0011] The aforementioned precision control device for tungsten needles in Invar alloy TIG oscillating welding includes a monitoring unit comprising a vision device and an image processing system connected thereto. The vision device is located beside the welding torch and directly faces the tungsten needle exposed at the bottom of the torch, monitoring the tungsten needle extension, the distance between the tungsten needle and the workpiece to be welded, and the arc size in real time. The image processing system receives information from the vision device, digitizes the information, and transmits the extracted digitized information to the PLC control cabinet.

[0012] The aforementioned tungsten needle precision control device for Invar alloy TIG oscillating welding has a hollow welding torch with square oscillating grooves at both its top and bottom. The first hydraulic device and the tungsten needle can move left and right within the square oscillating grooves.

[0013] In the aforementioned Invar alloy TIG oscillating welding tungsten needle precision control device, the special-type motor slides up and down along the lead screw to control the lower end of the wire feeding head and the lower end of the tungsten needle to be at the same height.

[0014] The aforementioned precision control device for tungsten needles in Invar alloy TIG oscillating welding is characterized in that: the top of the slide rail is provided with a protrusion extending to one side, and the lead screw is fixedly connected to the bottom of the protrusion; motor sliding positioning blocks connected to the protrusions are also provided on both sides of the slide rail, and each motor sliding positioning block is provided with a sliding groove.

[0015] The aforementioned Invar alloy TIG oscillating welding tungsten needle precision control device has guide shafts on both sides of the special-type motor, and the guide shafts are respectively fitted into sliding grooves on their corresponding sides.

[0016] The control method for the tungsten needle precision control device in TIG oscillating welding of Invar alloy includes the following steps:

[0017] 1) Before welding, turn on the vision device to measure and observe the dry extension of the tungsten needle above the workpiece to be welded, transmit the information to the image processing system, digitize the image, and further transmit the information to the PLC control cabinet.

[0018] 2) The PLC control cabinet makes logical judgments based on the information and transmits different electrical signals to the first hydraulic device, the second hydraulic device and the special motor to ensure that the tungsten needle is directly above the workpiece to be welded area, the welding wire is directly facing the tungsten needle, and the extension length and distance from the workpiece are reasonable.

[0019] 3) During the welding process, the vision device observes the TIG arc, transmits information to the image processing system, extracts the size and shape information of the arc, and sends the information to the PLC control cabinet.

[0020] 4) The PLC control cabinet judges the shape and size of the electric arc and transmits an electrical signal to the first hydraulic device. By adjusting the extension of the tungsten needle, it controls the morphology of the TIG welding arc to improve the welding quality.

[0021] In the above-mentioned control method of the tungsten needle precision control device for Invar alloy TIG oscillation welding, in step 3, during the TIG oscillation welding process, the PLC control cabinet sends different control signals to the first hydraulic device and the special motor to control the tungsten needle and the wire feeding head to have the same up and down oscillation amplitude.

[0022] The technical effects and advantages of this invention are as follows:

[0023] This invention provides a precise control device for the tungsten needle in TIG oscillating welding of Invar alloys. By combining a monitoring unit and a PLC control cabinet with the TIG welding unit, it achieves precise control and oscillation of the tungsten needle position during the oscillating welding of thick Invar alloys. The monitoring unit's vision device monitors the tungsten needle extension, distance from the workpiece, and arc shape and size in real time. The collected information is fed back to the image processing system for digital processing and transmitted to the PLC control cabinet. The PLC control cabinet receives the tungsten needle extension, distance from the workpiece, and arc shape and size information, performs logical judgments, and controls the tungsten needle extension, oscillation, and welding wire oscillation in real time through the control of hydraulic devices and special motors. This achieves control over the welding quality, enabling the welded structure of thick Invar alloys to meet the performance requirements of the operating environment. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention.

[0025] Reference numerals: 1. Image processing system; 2. PLC control cabinet; 3. Welding torch; 31. Tungsten needle; 32. Wire feeder; 33. Slide rail; 34. Clamping head; 35. First hydraulic device; 36. Second hydraulic device; 37. Special type motor; 38. Lead screw; 100. Workpiece to be welded. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the embodiments given in the accompanying drawings.

[0027] See Figure 1 As shown, a tungsten needle precision control device for Invar alloy TIG oscillating welding includes a TIG welding unit and a monitoring unit respectively connected to a PLC control cabinet 2. The monitoring unit is located next to the TIG welding unit and is used to monitor the tungsten needle position, extension length, and welding arc length in real time, and feed the monitored information back to the PLC control cabinet 2. The PLC control cabinet 2 controls the TIG welding unit to achieve precise control of the tungsten needle's position and orientation, and controls the welding wire to align with the tungsten needle, based on the information fed back by the monitoring unit.

[0028] In practice, by combining the monitoring unit and PLC control cabinet with the TIG welding unit, precise control and oscillation of the tungsten needle position were achieved during the TIG oscillation welding process of thick Invar alloy.

[0029] For specific implementation, please refer to Figure 1 As shown, the TIG welding unit includes a welding torch 3. The top center of the welding torch 3 is provided with a first hydraulic device 35 with one end extending into the welding torch 3, and a second hydraulic device 36 is disposed on both sides of the first hydraulic device 35 and can be pushed to swing left and right. A tungsten needle 31 with one end extending out of the bottom of the welding torch 3 is inserted into the first hydraulic device 35.

[0030] For specific implementation, please refer to Figure 1 As shown, a clamping head 34 is sleeved in the middle section of the welding torch 3, and a downwardly extending lead screw 38 is provided on the top of the slide rail 33. A special type motor 37 is sleeved on the lead screw 38. When the special type motor 37 is working, it can slide up and down along the lead screw 38. A wire feeding head 32 with one end extending to the side of the tungsten needle is clamped on the special type motor 37.

[0031] For specific implementation, please refer to Figure 1As shown, the monitoring unit includes a vision device 11 and an image processing system 1 connected thereto. The vision device 11 is located beside the welding torch 3 and directly faces the tungsten needle 31 exposed at the bottom of the welding torch 3. It monitors the extension of the tungsten needle 31, the distance between the tungsten needle 31 and the workpiece 100 to be welded, and the arc size in real time. The image processing system 1 is used to receive the information fed back by the vision device 11, digitize the information, and transmit the extracted digitized information to the PLC control cabinet 2.

[0032] In this embodiment, the vision device 11 is a 2D / 3D line laser sensing head, model LJ-X8080; the image processing system 1 is an XG-X2900LJ controller.

[0033] In specific implementation, the welding torch 3 is a hollow structure with square swing grooves on its top and bottom. When swing welding is required, the PLC control cabinet 2 can control the second hydraulic device 36 to push the first hydraulic device 35 and the tungsten needle 31 to move left and right in the square swing groove, thereby causing the tungsten needle 31 to swing left and right.

[0034] In practice, when welding alloy plates, the PLC control cabinet 2 controls the special motor 37 to slide up and down along the lead screw 38, thereby controlling the lower end of the wire feed head 32 to be at the same height as the lower end of the tungsten needle 31, thus ensuring the welding quality.

[0035] For specific implementation, please refer to Figure 1 As shown, to facilitate the installation of the lead screw 38, the top of the slide rail 33 is provided with a protrusion extending to one side, and the lead screw 38 is fixedly connected to the bottom of the protrusion. Motor sliding positioning blocks connected to the protrusions are also provided on both sides of the slide rail 33, and each motor sliding positioning block has a sliding groove. Guide shafts are provided on both sides of the special-type motor 37, and the guide shafts are respectively fitted into the sliding grooves on their corresponding sides. The design of the sliding grooves prevents the special-type motor 37 from shifting when swinging up and down, thus avoiding problems that could affect the welding quality.

[0036] In practice, the vision device 11 of the monitoring unit monitors the extension length, distance from the workpiece, and arc shape and size of the tungsten needle 31 in real time. The collected information is fed back to the image processing system 1 for digital processing and transmitted to the PLC control cabinet 2. The PLC control cabinet 2 receives the extension length, distance from the workpiece, and arc shape and size of the tungsten needle 31, performs logical judgment, and controls the extension length, oscillation of the tungsten needle and the oscillation of the welding wire in real time through the control hydraulic device and special motor 37. This enables control of welding quality, allowing the thick Invar alloy welded structure to meet the performance requirements of the service environment.

[0037] The following describes the control method for the tungsten needle precision control device in Invar alloy TIG oscillating welding, which includes the following steps:

[0038] 1) Before welding, turn on the vision device 11 to measure and observe the dry extension of the tungsten needle 31 above the workpiece 100 to be welded, transmit the information to the image processing system 1, and digitize the image, and further transmit the information to the PLC control cabinet 2.

[0039] 2) The PLC control cabinet 2 makes logical judgments based on the information and transmits different electrical signals to the first hydraulic device 35, the second hydraulic device 36 and the special motor 37 to ensure that the tungsten needle 31 is directly above the workpiece to be welded area, the welding wire is directly facing the tungsten needle 31, and the extension length and distance from the workpiece are reasonable.

[0040] 3) During the welding process, the vision device 11 observes the TIG arc, transmits information to the image processing system 1, extracts the size and shape information of the arc, and sends the information to the PLC control cabinet 2.

[0041] 4) The PLC control cabinet 2 makes a judgment based on the shape and size of the electric arc and transmits an electrical signal to the first hydraulic device 35. By adjusting the extension of the tungsten needle 31, the TIG welding arc morphology is controlled to improve the welding quality.

[0042] In practice, during the TIG oscillation welding process, the PLC control cabinet 2 sends different control signals to the first hydraulic device 35 and the special motor 37 to control the tungsten needle 31 and the wire feed head 32 to have the same up-and-down oscillation amplitude.

[0043] By adopting the above-mentioned control method, the tungsten needle 31 in the TIG oscillating welding process of Invar alloy is precisely controlled, providing a high-quality and highly flexible welding method for TIG oscillating welding of thick Invar alloy. It can accurately identify the cladding of the welding wire and precisely control the dry extension of the tungsten needle 31, thus solving the problem of poor cladding effect of domestic Invar alloy welding wire.

[0044] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A tungsten needle precision control device for Invar alloy TIG oscillating welding, characterized in that: It includes a TIG welding unit and a monitoring unit connected to the PLC control cabinet (2); the monitoring unit is located next to the TIG welding unit and is used to monitor the position, extension length and welding arc length of the tungsten needle (31) in real time and feed the monitored information back to the PLC control cabinet (2); the PLC control cabinet (2) controls the TIG welding unit to achieve precise adjustment of the position and orientation of the tungsten needle (31) and to control the welding wire to align with the tungsten needle (31) according to the information fed back by the monitoring unit. The TIG welding unit includes a welding torch (3), and the top center of the welding torch (3) is provided with a first hydraulic device (35) with one end extending into the welding torch (3), and a second hydraulic device (36) is arranged on both sides of the first hydraulic device (35) and can be pushed to swing left and right; a tungsten needle (31) with one end extending out of the bottom of the welding torch (3) is inserted into the first hydraulic device (35). A clamping head (34) is fitted in the middle section of the welding torch (3). A slide rail (33) is provided on one side of the clamping head (34). A screw (38) extending downward is provided at the top of the slide rail (33). A special motor (37) is fitted on the screw (38). When the special motor (37) is working, it can slide up and down along the screw (38). A wire feeding head (32) with one end extending to the side of the tungsten needle (31) is clamped on the special motor (37). The monitoring unit includes a vision device (11) and an image processing system (1) connected thereto. The vision device (11) is located next to the welding torch (3) and directly faces the tungsten needle (31) exposed at the bottom of the welding torch (3). It monitors the extension of the tungsten needle (31), the distance between the tungsten needle (31) and the workpiece (100) to be welded, and the size of the electric arc in real time. The image processing system (1) is used to receive the information fed back by the vision device (11), digitize the information, and transmit the extracted digitized information to the PLC control cabinet (2). The welding torch (3) is a hollow structure with square swing grooves at its top and bottom. The first hydraulic device (35) and the tungsten needle (31) can move left and right in the square swing grooves.

2. The tungsten needle precision control device for Invar alloy TIG oscillating welding according to claim 1, characterized in that: The special motor (37) slides up and down along the lead screw (38) to control the lower end of the wire feeding head (32) to be at the same height as the lower end of the tungsten needle (31).

3. The tungsten needle precision control device for Invar alloy TIG oscillating welding according to claim 1, characterized in that: The top of the slide rail (33) is provided with a protrusion extending to one side, and the lead screw (38) is fixedly connected to the bottom of the protrusion; on both sides of the slide rail (33) there are also motor sliding positioning blocks connected to the protrusions, and each motor sliding positioning block is provided with a sliding groove.

4. The tungsten needle precision control device for Invar alloy TIG oscillating welding according to claim 3, characterized in that: The special-type motor (37) is provided with guide shafts on both sides, and the guide shafts are respectively inserted into the sliding grooves on their corresponding sides.

5. The control method of the tungsten needle precision control device for Invar alloy TIG oscillating welding as described in any one of claims 1-4, characterized in that, Includes the following steps: 1) Before welding, turn on the vision device (11) to measure and observe the dry extension of the tungsten needle (31) above the workpiece (100) to be welded, transmit the information to the image processing system (1), and digitize the image, and further transmit the information to the PLC control cabinet (2). 2) The PLC control cabinet (2) makes logical judgments based on the information and transmits different electrical signals to the first hydraulic device (35), the second hydraulic device (36) and the special motor (37) to ensure that the tungsten needle (31) is directly above the workpiece to be welded area, the welding wire is directly opposite the tungsten needle (31), and the extension length and distance from the workpiece are reasonable. 3) During the welding process, the vision device (11) observes the TIG arc, transmits information to the image processing system (1), extracts the size and shape information of the arc, and sends the information to the PLC control cabinet (2). 4) The PLC control cabinet (2) makes a judgment based on the shape and size of the electric arc and transmits an electrical signal to the first hydraulic device (35). By adjusting the extension of the tungsten needle (31), the TIG welding arc morphology is controlled to improve the welding quality.

6. The control method of the tungsten needle precision control device for Invar alloy TIG oscillating welding according to claim 5, characterized in that: In step 3), during the TIG oscillation welding process, the PLC control cabinet (2) sends different control signals to the first hydraulic device (35) and the special motor (37) to control the tungsten needle (31) and the wire feed head (32) to have the same up and down oscillation amplitude.

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