Diffusion welding machine and control method thereof

Abstract

The invention discloses a diffusion welding machine and a control method thereof, and relates to the technical field of high-temperature molecular diffusion welding. The lower electrode plate is connected to a first pole of a power supply; the lower conducting layer is arranged on the lower electrode plate; the upper electrode plate is connected to a second pole of the power supply; the upper conductive layer is arranged at the bottom of the upper electrode plate; the driving part is used for driving the upper conducting layer to press or loosen the to-be-machined part, and after the upper conducting layer makes contact with the lower conducting layer, an electric loop is formed among the upper electrode plate, the to-be-machined part and the lower electrode plate; the grating main scale is arranged on one side of the workpiece to be machined; the reading head is connected to the output end of the driving piece, and the reading head is matched with the grating main ruler so as to detect the displacement value of the upper conducting layer when the upper conducting layer is pressed on the to-be-machined piece; and the control unit is used for controlling the driving piece to press down or lift up according to the displacement value detected by the reading head. The objective of the invention is to avoid the problems of large temperature detection result deviation and low test result repeatability caused by infrared temperature measurement.

Description

Technical Field

[0001] The invention relates to the technical field of high-temperature molecular diffusion welding, and in particular to a diffusion welding machine and a control method thereof. Background Art

[0002] As an important welding equipment, diffusion welding machine is widely used in welding conductive tape soft connection products and manufacturing double-layer or multi-layer metal products. Compared with traditional welding methods, diffusion welding technology has higher efficiency and good welding quality, and is especially suitable for welding dissimilar joints and materials. Its basic principle is to generate high temperature and pressure through electric current, so that the surface of the weldment diffuses at the atomic level, thereby achieving a firm connection effect.

[0003] In the diffusion welding process, due to the influence of high temperature and complex environment, temperature measurement and control become the key factors of welding quality. Traditionally, infrared thermometers are widely used for temperature monitoring in the welding process. Infrared thermometers measure the radiation intensity on the surface of an object to infer the temperature, which has the advantages of fast and non-contact. However, the accuracy of infrared thermometers in the welding process is affected by many factors.

[0004] The emissivity of different objects or the same object changes greatly during temperature changes. For example, when the temperature rises from room temperature to 950°C, the emissivity of the object will change significantly, and the difference in emissivity of different materials is even more obvious. This will cause deviations in the measurement results of the infrared thermometer and affect the accuracy of temperature monitoring.

[0005] Therefore, how to avoid the problem of large deviation in temperature detection results and low repeatability of test results caused by infrared temperature measurement has become a technical problem that needs to be solved urgently. Summary of the invention

[0006] The main purpose of the present invention is to provide a diffusion welding machine and a control method thereof, aiming to avoid the problems of large deviation of temperature detection results and low repeatability of test results caused by infrared temperature measurement.

[0007] In order to achieve the above object, the present invention provides a diffusion welding machine, comprising: A lower electrode plate connected to a first pole of a power source; A lower conductive layer, disposed on the lower electrode plate, for supporting the workpiece to be processed and enabling electrical connection between the workpiece to be processed placed on the lower conductive layer and the lower electrode plate; An upper electrode plate connected to the second pole of the power supply; An upper conductive layer, disposed at the bottom of the upper electrode plate; A driving member, used for driving the upper conductive layer to press or release the workpiece to be processed, and when the upper conductive layer is in contact with the lower conductive layer, an electrical circuit is formed between the upper electrode plate, the workpiece to be processed, and the lower electrode plate to heat the workpiece to be processed; A grating main scale is arranged on one side of the workpiece to be processed; A reading head connected to the output end of the driving member and capable of synchronously moving with the upper electrode plate, the reading head cooperates with the grating main scale to detect the displacement value of the upper conductive layer when the upper conductive layer is pressed against the workpiece to be processed; and The control unit controls the driving member to press down or lift up according to the displacement value detected by the reading head.

[0008] In one embodiment of the present application, the lower conductive layer and / or the upper conductive layer is a graphite layer.

[0009] In one embodiment of the present application, the driving member is a lifting cylinder.

[0010] The present application also discloses a control method for the above diffusion welding machine, comprising the following steps: S10: controlling the driving member to drive the upper electrode plate to approach the lower electrode plate at a first preset speed, and detecting whether an electrical circuit is formed between the upper electrode plate, the workpiece to be processed, and the lower electrode plate; S20: when an electrical circuit is formed between the upper electrode plate, the workpiece to be processed, and the lower electrode plate, controlling the driving member to drive the upper electrode plate to approach the lower electrode plate at a second preset speed; S30: Obtain the displacement parameters of the upper conductive layer, and determine whether the displacement parameters of the upper conductive layer meet the preset conditions. When the preset conditions are not met, reduce the current in the electric circuit or disconnect the electric circuit, and control the upper electrode plate to move away from the lower electrode plate to complete welding.

[0011] In one embodiment of the present application, the first preset speed is A, 220 mm / s ≥ A ≥ 3 mm / s.

[0012] In one embodiment of the present application, the second preset speed is B, 3mm / s≥A≥0mm / s.

[0013] In an embodiment of the present application, the displacement parameter includes one of a moving speed or a moving distance.

[0014] In one embodiment of the present application, when the displacement parameter is the moving speed, the moving speed is defined as C, and the preset condition is: C≤0.1 mm / s; When the displacement parameter is the moving distance, the moving distance is defined as D, and the preset condition is D≤0.02 mm.

[0015] By adopting the above technical solution, since the reading head can detect the displacement state of the upper electrode plate in real time, and combined with the characteristic that the compressive strength of the workpiece will gradually decrease with the increase of temperature when the upper electrode plate and the workpiece are diffusion welded, the state of the workpiece can be detected in real time without the need to use an infrared thermometer to measure the temperature, thus avoiding the large deviation of the temperature detection results caused by infrared temperature measurement and the low repeatability of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention is described in detail below with reference to specific embodiments and accompanying drawings, wherein: Figure 1 It is a structural schematic diagram of a first embodiment of the present invention; Figure 2 It is a schematic diagram of the flow structure of the control method of the present invention; 10. Lower electrode plate; 11. Lower conductive layer; 20. Upper electrode plate; 21. Upper conductive layer; 30. Driving element; 40. Frame. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the following specific embodiments are only used to explain the present invention and do not constitute a limitation to the present invention.

[0018] like Figure 1 As shown, in order to achieve the above-mentioned purpose, the present invention provides a diffusion welding machine, comprising: The lower electrode plate 10 is connected to the first pole of the power supply; The lower conductive layer 11 is disposed on the lower electrode plate 10 and is used to support the workpiece to be processed and to form an electrical connection between the workpiece to be processed placed on the lower conductive layer 11 and the lower electrode plate 10; The upper electrode plate 20 is connected to the second pole of the power supply; An upper conductive layer 21 is provided at the bottom of the upper electrode plate 20; The driving member 30 is used to drive the upper conductive layer 21 to press or release the workpiece to be processed. When the upper conductive layer 21 is in contact with the lower conductive layer 11, an electrical circuit is formed between the upper electrode plate 20, the workpiece to be processed, and the lower electrode plate 10 to heat the workpiece to be processed. A grating main scale is arranged on one side of the workpiece to be processed; A reading head connected to the output end of the driving member 30 and capable of synchronously moving with the upper electrode plate 20, the reading head cooperates with the grating main scale to detect the displacement value of the upper conductive layer when the upper conductive layer is pressed against the workpiece; The control unit controls the driving member 30 to be pressed down or lifted according to the displacement value detected by the reading head.

[0019] Specifically, the diffusion welding machine includes a lower electrode plate 10, which is fixedly mounted on a frame 40 by fasteners and connected to a first pole of a power supply by a wire. The lower conductive layer 11 is made of a conductive material, and the lower conductive layer can be made of pre-oxidized graphite. When the lower conductive layer is made of pre-oxidized graphite, it is fixedly mounted on the lower electrode plate 10 by fasteners to provide a uniform conductive contact surface, so that the workpiece placed on the lower conductive layer 11 can be stably electrically connected to the lower electrode plate 10.

[0020] The upper electrode plate 20 is made of a conductive material and is connected to the frame 40 through a supporting mechanism and is connected to the second pole of the power supply through a wire to ensure that a current path is formed between the upper electrode plate 20 and the lower electrode plate 10 during operation. An upper conductive layer 21 is fixed to the bottom of the upper electrode plate 20, and the material of the upper conductive layer 21 is consistent with that of the lower conductive layer 11.

[0021] The driving member 30 includes a hydraulic cylinder or a pneumatic cylinder, and the output end of the driving member 30 is connected to the upper electrode plate 20 to drive the upper electrode plate 20 to move in the vertical direction under the command of the control unit, thereby controlling the pressure state of the upper conductive layer 21 on the workpiece to be processed. When the driving member 30 drives the upper electrode plate 20 to press down until the upper conductive layer 21 contacts the workpiece to be processed, the upper electrode plate 20, the workpiece to be processed and the lower electrode plate 10 form a closed circuit, and the workpiece to be processed is heated under the action of the current, thereby achieving diffusion welding.

[0022] The grating main scale is installed on one side of the workpiece to be processed and remains fixed. The reading head is installed on the output end of the driving member 30, and moves synchronously with the movement of the upper electrode plate 20. The detection signal of the reading head is transmitted to the control unit through the data line. Based on the displacement value data provided by the reading head, the control unit adjusts the action of the driving member 30 in real time to ensure that the upper conductive layer 21 applies a stable pressure to the workpiece to be processed, and controls the driving member 30 to lift the upper electrode plate 20 after the welding is completed, so that the diffusion welding machine is in a standby state. It can be imagined that after the welding is completed, when the control unit controls the driving member 30 to lift, it can first stabilize the voltage for a predetermined time, and then lift it after the predetermined time ends, thereby improving the welding effect.

[0023] By adopting the above technical scheme, since the reading head can detect the displacement state of the upper electrode plate 20 in real time, and combined with the characteristic that the compressive strength of the workpiece will gradually decrease with the increase of temperature when the upper electrode plate 20 and the workpiece are diffusion welded, the state of the workpiece can be detected in real time without the need to use an infrared thermometer to measure the temperature, thereby avoiding the large deviation of the temperature detection results caused by infrared temperature measurement and the low repeatability of the test results.

[0024] In one embodiment of the present application, the lower conductive layer 11 and / or the upper conductive layer 21 is a graphite layer.

[0025] Specifically, the lower conductive layer 11 is a graphite layer, and the graphite layer is fixed to the surface of the lower electrode plate 10 by physical clamping. The physical clamping in the present application is realized by a first clamping cylinder and a second clamping cylinder, the fixed part of the first clamping cylinder is connected to the lower electrode plate, the fixed part of the second clamping cylinder is connected to the lower electrode plate, the first clamping cylinder and the second clamping cylinder are arranged opposite to each other, and a clamping space for clamping the graphite layer is formed between the movable part of the first clamping cylinder and the movable part of the second clamping cylinder, and the movable part of the first clamping cylinder and the movable part of the second clamping cylinder can be close to or away from each other to realize the clamping of the graphite layer.

[0026] The graphite layer has good electrical conductivity and high temperature resistance, so that after the workpiece is placed on the lower conductive layer 11, it can form a stable electrical connection with the lower electrode plate 10, reduce electrical contact resistance, and improve heating uniformity.

[0027] The upper conductive layer 21 is also a graphite layer, which is firmly connected to the upper electrode plate 20 by physical clamping. The upper conductive layer 21 is made of the same material as the lower conductive layer 11, so that the workpiece can be heated evenly in the clamped state, while avoiding the resistance change caused by the contact of different materials, thereby improving the stability of welding. It is conceivable that the materials of the upper conductive layer 21 and the lower conductive layer 11 can also be different, so as to form a temperature difference between the upper conductive layer 21 and the lower conductive layer 11, so as to adapt to the welding of dissimilar materials.

[0028] By adopting the above technical solution, the lower conductive layer 11 and the upper conductive layer 21 are both made of graphite layers, so that the diffusion welding machine can maintain stable conductivity in a high temperature environment. At the same time, the high heat resistance and oxidation resistance of the graphite layer itself effectively reduce the material loss during the welding process and increase the service life of the equipment. In addition, since the surface of the graphite layer has good embedding properties, it can reduce the damage to the workpiece during the pressure application process and improve the reliability of the welding effect.

[0029] In one embodiment of the present application, the driving member 30 is a lifting cylinder.

[0030] Specifically, the driving member 30 is a lifting cylinder, the cylinder body of the lifting cylinder is fixed on the frame 40, and the piston rod is connected to the upper electrode plate 20. The control unit controls the extension and contraction of the lifting cylinder by adjusting the air source pressure, thereby driving the upper electrode plate 20 to move in the vertical direction, so that the upper conductive layer 21 presses or loosens the workpiece to be processed. When the lifting cylinder drives the upper electrode plate 20 to press down until the upper conductive layer 21 contacts the workpiece to be processed, and the workpiece to be processed is placed on the lower conductive layer 11, the upper electrode plate 20, the workpiece to be processed and the lower electrode plate 10 form a closed circuit, and the workpiece to be processed is heated under the action of the current, thereby achieving diffusion welding.

[0031] With the above technical solution, the driving member 30 uses a lifting cylinder, and the upper electrode plate 20 can be precisely controlled by adjusting the gas source pressure to ensure the pressure stability of the upper conductive layer 21 on the workpiece during welding. Since the cylinder drive method has a fast response speed, a simple structure and is easy to maintain, the diffusion welding machine has high reliability in practical applications.

[0032] like Figure 2 As shown, the present application also discloses a control method for the above diffusion welding machine, comprising the following steps: S10: Control the driving member 30 to drive the upper electrode plate 20 to approach the lower electrode plate 10 at a first preset speed, and detect whether an electrical circuit is formed between the upper electrode plate 20, the workpiece to be processed, and the lower electrode plate 10; S20: When an electrical circuit is formed between the upper electrode plate 20, the workpiece to be processed, and the lower electrode plate 10, the driving member 30 is controlled to drive the upper electrode plate 20 to approach the lower electrode plate 10 at a second preset speed; S30: Obtain the displacement parameters of the upper conductive layer 21, and determine whether the displacement parameters of the upper conductive layer 21 meet the preset conditions. When the preset conditions are not met, reduce the current in the electrical circuit or disconnect the electrical circuit, and control the upper electrode plate 20 to move away from the lower electrode plate 10 to complete welding.

[0033] Specifically, in step S10, the control unit sends a control signal to the lifting cylinder to control the lifting cylinder to drive the upper electrode plate 20 to move downward at a first preset speed, so that the upper conductive layer 21 gradually approaches the workpiece to be processed. As the upper conductive layer 21 is pressed downward, the control unit monitors the state of the electrical circuit between the upper electrode plate 20, the workpiece to be processed, and the lower electrode plate 10 in real time. When it is detected that an electrical circuit is formed between the upper electrode plate 20, the workpiece to be processed, and the lower electrode plate 10, it means that the upper conductive layer 21 has contacted with the workpiece to be processed, and the workpiece to be processed has also established a conductive connection with the lower conductive layer 11, and the workpiece to be processed begins to be heated, and the welding preparation work is completed.

[0034] In step S20, the control unit sends an adjustment signal to the lifting cylinder to control the lifting cylinder to continue to drive the upper electrode plate 20 to move downward at a second preset speed, so that the upper conductive layer 21 further presses the workpiece to be processed to ensure that the upper conductive layer 21 applies a stable and appropriate pressure to the workpiece to be processed during the welding process, thereby ensuring the welding quality.

[0035] In step S30, as the temperature rises, the compressive strength of the workpiece to be processed will gradually decrease. Under the action of pressure, the welded part will undergo plastic deformation. At this time, the upper conductive layer 21 will slowly move downward. At this time, the control unit obtains the displacement parameters of the upper conductive layer 21 in real time through the reading head, and compares the obtained displacement parameters with the preset conditions. If the displacement parameters do not meet the preset conditions, it indicates that the welding of the current workpiece to be processed has been completed. At this time, the control unit adjusts the welding current, reduces the current in the electrical circuit, or directly disconnects the electrical circuit, and controls the lifting cylinder to drive the upper electrode plate 20 away from the lower electrode plate 10 to complete the welding process.

[0036] By adopting the above technical solution, the control method of the diffusion welding machine ensures that the upper conductive layer 21 can stably contact the workpiece to be processed by adjusting the movement speed of the lifting cylinder in stages, and maintains a reasonable pressure during the welding process, thereby improving the stability of the welding quality. By real-time monitoring of the state of the electrical circuit, the contact between the upper electrode plate 20 and the workpiece to be processed can be accurately judged, making the welding start-up process more accurate and reliable. In addition, by detecting the displacement parameters of the upper conductive layer 21 through the reading head and judging in combination with the preset conditions, the current can be dynamically adjusted or the welding can be terminated during the welding process, realizing the dynamic adjustment of the welding state without the participation of infrared detection parts, and improving the intelligent control level and safety of the welding process.

[0037] In one embodiment of the present application, the first preset speed is A, 220 mm / s ≥ A ≥ 3 mm / s.

[0038] Specifically, the control unit sends a control signal to the lifting cylinder, so that the lifting cylinder drives the upper electrode plate 20 to move downward at a first preset speed, so that the upper conductive layer 21 gradually approaches the workpiece to be processed. The range of the first preset speed is set between 220mm / s and 3mm / s, so that the upper conductive layer 21 can smoothly and quickly approach the workpiece to be processed to ensure the stability and speed of the welding startup process. When the upper conductive layer 21 is gradually pressed down, the control unit monitors the state of the electrical circuit between the upper electrode plate 20, the workpiece to be processed and the lower electrode plate 10 in real time. When it is detected that an electrical circuit is formed between the upper electrode plate 20, the workpiece to be processed and the lower electrode plate 10, it means that the upper conductive layer 21 has contacted with the workpiece to be processed, and the workpiece to be processed establishes a conductive connection with the lower conductive layer 11, and the workpiece to be processed begins to be heated, and the welding preparation work is completed.

[0039] By adopting the above technical solution, the control unit sets the range of the first preset speed between 220 mm / s and 3 mm / s, thereby ensuring that the upper conductive layer 21 can stably approach the workpiece to be processed, thereby improving welding efficiency.

[0040] In one embodiment of the present application, the second preset speed is B, 3mm / s≥A≥0mm / s.

[0041] Specifically, the control unit sends an adjustment signal to the lifting cylinder, so that the lifting cylinder drives the upper electrode plate 20 to continue to move downward at a second preset speed, so that the upper conductive layer 21 further presses the workpiece to be processed, so as to ensure that the upper conductive layer 21 applies a stable and appropriate pressure to the workpiece during welding, thereby ensuring the welding quality. The range of the second preset speed is set between 3 mm / s and 0 mm / s, so that the upper conductive layer 21 can slowly apply pressure to the workpiece to be processed, so as to avoid affecting the welding effect due to too fast pressure changes.

[0042] By adopting the above technical solution, the control unit sets the second preset speed range between 3mm / s and 0mm / s, so that the upper conductive layer 21 applies pressure slowly and evenly during the welding process, ensuring that the workpiece to be processed maintains a stable stress state during the welding process, thereby effectively preventing welding deformation and improving the stability and reliability of welding quality.

[0043] In an embodiment of the present application, the displacement parameter includes one of a moving speed or a moving distance.

[0044] The adoption of the above technical solution improves the accuracy of displacement parameter judgment.

[0045] In one embodiment of the present application, when the displacement parameter is the moving speed, the moving speed is defined as C, and the preset condition is: C≤0.1 mm / s; When the displacement parameter is the moving distance, the moving distance is defined as D, and the preset condition is D≤0.02 mm.

[0046] Specifically, the control unit obtains the displacement parameters of the upper conductive layer 21 in real time through the reading head, and compares the obtained displacement parameters with the preset conditions. When the displacement parameter is the moving speed, the control unit obtains the moving speed of the upper conductive layer 21, and determines whether the moving speed is less than or equal to 0.1mm / s; when the displacement parameter is the moving distance, the control unit obtains the moving distance of the upper conductive layer 21, and determines whether the moving distance is less than or equal to 0.02mm. If the moving speed or moving distance does not meet the corresponding preset conditions, it indicates that the welding of the workpiece to be processed has been completed, the control unit adjusts the welding current, reduces the current in the electrical circuit, or directly disconnects the electrical circuit, and controls the lifting cylinder to drive the upper electrode plate 20 away from the lower electrode plate 10 to complete the welding process.

[0047] By adopting the above technical solution, the control unit sets preset conditions for the moving speed and moving distance to make the welding termination judgment more accurate, avoiding incomplete welding due to insufficient welding time or material damage due to excessive welding time, thereby improving the stability and consistency of welding quality.

[0048] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A diffusion welding machine, characterized in that: include: A lower electrode plate connected to a first pole of a power source; A lower conductive layer, disposed on the lower electrode plate, for supporting the workpiece to be processed and enabling electrical connection between the workpiece to be processed placed on the lower conductive layer and the lower electrode plate; An upper electrode plate connected to the second pole of the power supply; An upper conductive layer, disposed at the bottom of the upper electrode plate; A driving member, used for driving the upper conductive layer to press or release the workpiece to be processed, and when the upper conductive layer is in contact with the lower conductive layer, an electrical circuit is formed between the upper electrode plate, the workpiece to be processed, and the lower electrode plate to heat the workpiece to be processed; A grating main scale is arranged on one side of the workpiece to be processed; A reading head connected to the output end of the driving member and capable of synchronously moving with the upper electrode plate, the reading head cooperates with the grating main scale to detect the displacement value of the upper conductive layer when the upper conductive layer is pressed against the workpiece to be processed; as well as The control unit controls the driving member to press down or lift up according to the displacement value detected by the reading head.

2. The diffusion bonding machine according to claim 1, wherein: The lower conductive layer and / or the upper conductive layer is a graphite layer.

3. The diffusion bonding machine according to claim 1, wherein: The driving member is a lifting cylinder.

4. A control method for a diffusion bonding machine according to any one of claims 1 to 3, characterized in that: The following steps are involved: S10: controlling the driving member to drive the upper electrode plate to approach the lower electrode plate at a first preset speed, and detecting whether an electrical circuit is formed between the upper electrode plate, the workpiece to be processed, and the lower electrode plate; S20: when an electrical circuit is formed between the upper electrode plate, the workpiece to be processed, and the lower electrode plate, controlling the driving member to drive the upper electrode plate to approach the lower electrode plate at a second preset speed; S30: Obtain the displacement parameters of the upper conductive layer, and determine whether the displacement parameters of the upper conductive layer meet the preset conditions. When the preset conditions are not met, reduce the current in the electric circuit or disconnect the electric circuit, and control the upper electrode plate to move away from the lower electrode plate to complete welding.

5. The diffusion bonding machine according to claim 4, wherein: The first preset speed is A, 220 mm / s ≥ A ≥ 3 mm / s.

6. The diffusion bonding machine according to claim 4, wherein: The second preset speed is B, 3mm / s≥A≥0mm / s.

7. The diffusion bonding machine according to claim 4, characterized in that: The displacement parameter includes one of a moving speed or a moving distance.

8. The diffusion bonding machine according to claim 7, characterized in that: When the displacement parameter is the moving speed, the moving speed is defined as C, and the preset condition is: C≤0.1 mm / s; When the displacement parameter is the moving distance, the moving distance is defined as D, and the preset condition is D≤0.02 mm.

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