Resistance type diffusion brazing device and control method thereof

Abstract

The invention discloses a resistance-type diffusion brazing device and a control method thereof, and relates to the technical field of welding. The resistance type diffusion brazing device comprises a control unit, a welding unit, a feeding unit and a monitoring unit, and the control method is used for cooperatively controlling the multiple units. According to the resistance-type diffusion brazing device and the control method thereof, on the hardware level, the feeding mechanical arm and the soldering paste mechanical arm are used for replacing early-stage workpiece pretreatment, standardized workpiece feeding and soldering paste coating are achieved, meanwhile, through the control method, the temperature, pressure and time can be accurately controlled in the whole welding process, and the welding quality is improved. Meanwhile, uniform pressure is guaranteed through the leveling mechanism, most prominently, a set of strict soldering paste coating judgment process is adopted, it is guaranteed that soldering paste coating between the two workpieces to be welded is completely and strictly located in the standard range, the welding quality is further guaranteed, and overall automation and rapidness are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of welding, in particular to a resistance diffusion brazing device and a control method thereof. Background Art

[0002] Resistance diffusion soldering technology is a technology that utilizes the resistance of the objects to be soldered. By applying solder paste between the two and then applying current, the objects to be soldered generate heat when the current passes through them. At the same time, reasonable pressure is applied to allow the solder paste to penetrate into the workpiece, thereby firmly soldering the objects to be soldered together.

[0003] The common resistance diffusion brazing devices currently on the market usually require pretreatment during welding, in which the workpiece is coated with solder paste to form a combination, and then placed in a welding machine for welding. However, during the entire process, on the one hand, the degree of automation is low, and the welding effect is greatly affected by the solder paste coating state during the early workpiece pretreatment. On the other hand, during the welding process, the temperature, pressure and welding time are usually controlled by a preset program. However, in the actual welding process, due to the influence of the workpiece material, external environment and welding machine power, it is impossible to guarantee that the welding effect reaches the expected result. In addition, during welding, during the pressurization process, if the surface pressure of the workpiece is uneven, there will be differences in the fusion of the solder paste and the workpiece between the two workpieces, further affecting the welding effect. For this purpose, a group of resistance diffusion brazing devices and control methods thereof are specially provided. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a resistance diffusion brazing welding device and a control method thereof, which solves the problem that the welding effect of the existing resistance diffusion brazing welding device cannot achieve the expected effect due to multiple factors such as the initial workpiece pretreatment effect, the welding process technology and the pressure control during welding.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a resistance diffusion brazing device, comprising: Control unit; A welding unit, comprising a welding machine and an upper mold and a lower mold arranged opposite to each other; A loading unit, comprising a loading robot and a solder paste robot, wherein the loading robot comprises a robot arm disposed on one side of the lower mold and a workpiece loading mechanism mounted on the robot arm, and the solder paste robot comprises a robot arm disposed on the other side of the lower mold and a solder paste coating mechanism mounted on the robot arm; A monitoring unit, which includes a temperature monitoring mechanism and a visual module; The welding machine monitors the temperature of the upper mold, the lower mold and the workpiece through a temperature monitoring mechanism, thereby welding the workpiece; The loading unit monitors the state of the workpiece on the surface of the lower mold through a visual module, thereby loading and unloading the workpiece.

[0006] Preferably, the control unit includes a frame and a control host installed in the frame, the welding machine is installed inside the frame, a support column is fixedly provided on the outside of the frame, the lower mold is fixedly provided at the bottom end of the support column, the upper mold is slidably provided on the support column, a fixed carrier plate is fixedly provided on the top of the support column, a driving cylinder is installed on the top of the fixed carrier plate, the output end of the driving cylinder is fixedly connected to the upper mold, and a leveling mechanism is installed on the upper mold.

[0007] Preferably, the leveling mechanism comprises: A movable plate, which is slidably arranged on the outer surface of the support column, and the top of which is fixedly connected to the output end of the driving cylinder; A connecting plate is arranged at the bottom of the movable plate, and the upper mold is fixedly arranged at the bottom of the connecting plate; A leveling hemisphere, which is fixedly arranged in the middle of the top surface of the connecting plate; A leveling seat, which is fixedly arranged in the middle of the movable plate and directly opposite to the leveling hemisphere; A top bolt, which is threadedly connected in the movable plate and has its bottom end butted against the top of the connecting plate; The tension bolts are threadedly connected in the connecting plate and movably penetrate the movable plate.

[0008] Preferably, a bottom support plate is fixedly provided on the outside of the frame, the support column is fixedly provided on the bottom support plate, the temperature monitoring mechanism and the two groups of robotic arms are respectively provided on both sides of the bottom support plate, the vision module includes a first vision camera and a second vision camera respectively installed on the support columns on both sides, and a third vision camera installed on the movable plate, the first vision camera, the second vision camera and the third vision camera are arranged in a triangle to form a visual cross on the lower mold.

[0009] Preferably, the temperature monitoring mechanism comprises: A cantilever plate, which is mounted on the bottom support plate; A vertical frame, which is fixedly arranged on the cantilever plate; A driving screw rod is rotatably mounted on a vertical frame; A sliding seat is slidably disposed on the vertical frame and is threadedly connected to the driving screw; An adjusting handle, which is fixedly arranged on the top end of the driving screw rod; A sensor fixing frame, which is mounted on the sliding seat; A temperature sensor is fixedly installed in a sensor fixing frame; Two groups of adjustment slots are respectively provided on the cantilever plate and the sensor fixing frame, and are used to fix the cantilever plate and the sensor fixing frame by bolts after adjusting the angles.

[0010] Preferably, the mechanical arm comprises: A base, which is fixedly arranged on the bottom support plate; A rotary servo, which is fixedly arranged at the bottom of the base; A stabilizing frame, which is fixedly arranged on the base; A linear rail, the rotation of which is disposed between the base and the stabilizing frame; Two sets of gears are rotatably arranged in the base, and the two sets of gears are meshed with each other, and the two sets of gears are respectively fixedly connected to the rotary servo output end and the linear rail; A sliding connection part, which is slidably arranged on the outer wall of the linear rail; A pneumatic telescopic rod is rotatably arranged on a sliding connection portion, and a rotating motor for driving the pneumatic telescopic rod to rotate is fixedly arranged on the sliding connection portion; A lifting motor is fixedly arranged on the top of the linear rail; The lifting screw rod is rotatably arranged on the linear rail, and the top end of the lifting screw rod is fixedly connected to the output shaft of the lifting motor, and the sliding connection part is threadedly connected to the output shaft of the lifting motor.

[0011] Preferably, the workpiece loading mechanism includes a positioning servo motor fixedly arranged at the output end of a group of pneumatic telescopic rods and a clamp seat rotatably arranged at the end of the pneumatic telescopic rods, the output end of the positioning servo motor is fixedly connected to the clamp seat, and a plurality of pneumatic clamps are fixedly installed in the clamp seat, and the plurality of pneumatic clamps are distributed on the clamp seat in an equidistant annular array, and the workpiece loading mechanism also includes three groups of conveyor belts, and the three groups of conveyor belts are arranged side by side under the pneumatic telescopic rods.

[0012] Preferably, the solder paste coating mechanism includes a solder paste nozzle fixedly arranged at the output end of another group of pneumatic telescopic rods and a solder paste heating chamber fixedly arranged on one side of the bottom support plate, a hose pump is installed on the top of the solder paste heating chamber, a material guide pipe is installed between the solder paste nozzle and the hose pump, a metering pump is installed on the material guide pipe, and an electric heating insulation sleeve is installed on the outer wall of the material guide pipe.

[0013] Preferably, a control method of a resistance diffusion brazing device comprises the following steps; Step 1: Start the machine and level the upper mold; Step 2: The welding machine preheats the upper mold and the lower mold; Step 3: Monitor the temperature of the lower mold through the temperature sensor and set the temperature threshold H1. When the temperature reaches H1, start loading the workpiece through the loading unit; Step 4: The upper mold moves down to pre-press the workpiece on the lower mold. The pre-pressing is divided into two stages. The pressure value of the first stage is 2Mpa, and the pre-pressing time is 5s. Then the pressure is increased to 3Mpa in the second stage, and then the pressure is maintained. Step 5: Set the temperature threshold H2 and the pressure threshold P3, P3<3Mpa, detect the temperature on the mold side, when the temperature reaches H2, reduce the pressure to P3, and then apply pulsating direct current to the workpiece to heat it using the workpiece's own resistance; Step 6: Set the temperature threshold H3 and the pressure threshold P4. When the mold temperature reaches H3, start the pressure ramp program, slowly increase the pressure from P3 to P4, and then maintain the pressure for 2 seconds. Step seven: the upper mold is moved upward and reset, and the workpiece is unloaded through the loading unit.

[0014] Preferably, the process of loading and unloading materials by the loading unit in step 3 and step 7 includes: S1. The loading robot grabs workpiece A and workpiece B from the conveyor belt used for loading, where the number of workpiece A is greater than 1, the number of workpiece B is 1, the robot has vacant positions ≥ 1, and the solder paste robot preheats the solder paste; S2. Use the visual module to detect whether there is material on the lower mold. If there is material, the loading robot grabs the material. If there is no material on the lower mold, the loading robot places the workpiece A on the lower mold; S3, the workpiece A on the mold is positioned by the visual module, and then the solder paste robot applies solder paste; S4, the visual module detects whether there is solder paste on workpiece A. If not, the machine stops and reports an error. The maintenance personnel detect whether it is an error in the visual module that causes the solder paste coating position to be incorrect; or a fault in the solder paste robot that causes the paste to be unable to be dispensed; if there is solder paste on workpiece A, the next step is to make a judgment; S5. When solder paste exists on workpiece A, it is determined whether the solder paste is pressed. If so, workpiece A is taken away by the loading robot, and then the lower mold is repositioned to place a new workpiece A. If not, the next step is determined. S6. If the solder paste on workpiece A is not pressed, the solder paste coverage area ratio S on workpiece A is detected, and the area ratio thresholds Smin=60% and Smax=85% are set to determine whether Smin<S<Smax is established. If S is not in this interval, the workpiece A is taken away by the loading robot, and then a new workpiece A is placed. If S is in this interval, the next step of determination is performed; S7. When Smin<S<Smax holds true, the amount of solder paste added is obtained through a metering pump, and the average solder paste thickness L is calculated based on the amount added and the proportion of the solder paste area. The thickness thresholds Lmin=0.12mm and Lmax=0.15mm are set, and then a judgment is made. If L is within this range, the position of workpiece A is located through the visual module, and workpiece B is placed on workpiece A through the loading robot. Then the loading robot places the finished workpiece and workpiece A that failed to be coated with solder paste on two conveyor belts for unloading. At this time, loading is completed and the welding process is waiting to end.

[0015] The present invention discloses a resistance diffusion brazing device and a control method thereof, which have the following beneficial effects: 1. The resistance diffusion brazing device is provided with a feeding unit and a monitoring unit. The monitoring unit provides a visual solution for the feeding unit, so that the feeding unit can automatically coat the workpiece and solder paste, thereby replacing the previous pretreatment process of the welding workpiece, which is more efficient and the workpiece pretreatment is more standardized. At the same time, the leveling mechanism is used to achieve leveling of the upper mold, thereby effectively avoiding the problem of poor welding effect caused by workpiece pretreatment and uneven pressure during welding.

[0016] 2. The control method of the resistance diffusion brazing device realizes the monitoring of the workpiece temperature by setting a temperature sensor, and realizes the pressure control during the pressure application process of the workpiece by a pressure monitoring module, and monitors the workpiece temperature in real time by a temperature sensor, so as to ensure that the actual temperature and pressure are carefully controlled during the processing. In the process of welding the workpiece, a pressure ramp program is adopted to allow the pressure to be slowly fed, ensuring that the solder paste can evenly diffuse and metallurgically bond with the interface of the workpiece base material during the workpiece welding process, thereby ensuring the quality of the welding surface and avoiding the occurrence of poor welding effects due to differences in temperature and pressure values.

[0017] 3. The control method of the resistive diffusion brazing device, during the process of loading and unloading workpieces, a loading and unloading method is specifically designed to control the entire loading unit, so that the loading robot can pick up the workpiece after welding and place the new workpiece through multiple pneumatic clamps arranged in the surface array, which is more convenient to use. At the same time, a strict solder paste coating judgment process is designed to ensure that the solder paste coating between the two workpieces to be welded meets the welding standards, avoiding the situation where the welding effect does not meet the expectations due to substandard solder paste coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 This is a schematic diagram of the overall front structure of the welding device of the present invention; Figure 2 This is a schematic diagram of the overall back structure of the welding device of the present invention; Figure 3 This is a schematic diagram of the outer surface structure of the welding unit of the present invention; Figure 4This is a schematic diagram of the bottom structure of the welding unit of the present invention; Figure 5 This is a schematic diagram of the internal structure of the welding unit of the present invention; Figure 6 It is a schematic diagram of the structure of the temperature monitoring mechanism of the present invention; Figure 7 This is a schematic diagram of the structure of the feeding robot of the present invention; Figure 8 This is a schematic diagram of the structure of the feeding robot of the present invention; Fig. 9 It is a schematic diagram of the structure of the leveling mechanism of the present invention; Fig.10 This is an overall flow chart of the welding device control method of the present invention; Fig.11 This is a flow chart of workpiece loading and unloading in the welding device control method of the present invention.

[0020] In the figure: 1. control unit; 12. control host; 2. Welding unit; 21. Welding machine; 22. Upper mold; 23. Leveling mechanism; 24. Lower mold; 25. Support column; 26. Driving cylinder; 27. Bottom support plate; 28. Fixed carrier plate; 231, movable plate; 232, connecting plate; 233, leveling hemisphere; 234, leveling seat; 235, top bolt; 236, tension bolt; 3. Temperature monitoring mechanism; 31. Overhanging plate; 32. Vertical frame; 33. Driving screw rod; 34. Sliding seat; 35. Adjusting handle; 36. Adjusting slot; 37. Sensor fixing frame; 38. Temperature sensor; 4. Loading unit; 41. Workpiece loading mechanism; 42. Solder paste coating mechanism; 43. Robotic arm; 411, position selection servo motor; 412, fixture seat; 413, pneumatic fixture; 414, conveyor belt; 421, solder paste nozzle; 422, material guide tube; 423, solder paste heating chamber; 424, hose pump; 431, base; 432, rotary servo; 433, gear; 434, stabilizing frame; 435, linear rail; 436, sliding connection; 437, pneumatic telescopic rod; 438, rotary motor; 439, lifting motor; 4310, lifting screw; 5. Visual module; 51. First visual camera; 52. Second visual camera; 53. Third visual camera. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The embodiment of the present application provides a resistance diffusion brazing device and a control method thereof, thereby solving the problem that the welding effect of the existing resistance diffusion brazing device cannot reach the expected effect due to the influence of multiple factors such as the effect of early workpiece pretreatment, welding process technology and pressure control during welding.

[0023] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0024] Embodiment 1 The embodiment of the invention discloses a resistance diffusion brazing device.

[0025] According to the attached Figure 1-9 As shown, it includes a control unit 1, a welding unit 2, a monitoring unit and a feeding unit 4. The welding unit 2 includes a welding machine 21 and an upper mold 22 and a lower mold 24 arranged relatively. Electric heating wires are respectively arranged in the upper mold 22 and the lower mold 24, and a current loop is designed at the same time, so as to realize electric heating of the upper mold 22 and the lower mold 24 to achieve the purpose of preheating, and a built-in temperature monitoring module and a pressure monitoring module are used for temperature monitoring during mold preheating and pressure monitoring during welding; the feeding unit 4 includes a feeding manipulator and a solder paste manipulator, and the feeding machine The manipulator includes a robotic arm 43 arranged on one side of the lower mold 24 and a workpiece loading mechanism 41 installed on the robotic arm 43, and the solder paste robot includes a robotic arm 43 arranged on the other side of the lower mold 24 and a solder paste coating mechanism 42 installed on the robotic arm 43; the monitoring unit includes a temperature monitoring mechanism 3 and a visual module 5; the welding machine 21 monitors the temperature of the upper mold 22, the lower mold 24 and the workpiece through the temperature monitoring mechanism 3, thereby welding the workpiece; the loading unit 4 monitors the workpiece state on the surface of the lower mold 24 through the visual module 5, thereby loading and unloading the workpiece.

[0026] The control unit 1 includes a frame and a control host 12 installed in the frame, a welding machine 21 is installed inside the frame, a support column 25 is fixedly provided on the outside of the frame, a lower mold 24 is fixedly provided at the bottom end of the support column 25, an upper mold 22 is slidably provided on the support column 25, a fixed carrier plate 28 is fixedly provided on the top end of the support column 25, a driving cylinder 26 is installed on the top end of the fixed carrier plate 28, an output end of the driving cylinder 26 is fixedly connected to the upper mold 22, and a leveling mechanism 23 is installed on the upper mold 22.

[0027] The leveling mechanism 23 includes a movable plate 231, a connecting plate 232, a leveling hemisphere 233, a leveling seat 234, a top bolt 235 and a tension bolt 236. The movable plate 231 is slidably set on the outer surface of the support column 25, and its top is fixedly connected to the output end of the driving cylinder 26; the connecting plate 232 is set at the bottom of the movable plate 231, and the upper mold 22 is fixedly set at the bottom of the connecting plate 232; the leveling hemisphere 233 is fixedly set in the middle of the top surface of the connecting plate 232; the leveling seat 234 is fixedly set in the middle of the movable plate 231, and it is opposite to the leveling hemisphere 233; the top bolt 235 is threadedly connected to the movable plate 231, and its bottom end is against the top of the connecting plate 232; the tension bolt 236 is threadedly connected to the connecting plate 232, and it moves through the movable plate 231.

[0028] A bottom support plate 27 is fixedly provided on the outside of the frame, and a support column 25 is fixedly provided on the bottom support plate 27. The temperature monitoring mechanism 3 and two groups of robotic arms 43 are respectively provided on both sides of the bottom support plate 27. The visual module 5 includes a first visual camera 51 and a second visual camera 52 respectively installed on the support columns 25 on both sides, and a third visual camera 53 installed on the movable plate 231. The first visual camera 51, the second visual camera 52 and the third visual camera 53 are arranged in a triangle to form a visual cross on the lower mold 24.

[0029] The temperature monitoring mechanism 3 includes a cantilever plate 31, a vertical frame 32, a driving screw rod 33, a sliding seat 34, an adjustment handle 35, an adjustment slot 36, a sensor fixing frame 37 and a temperature sensor 38. The cantilever plate 31 is installed on the bottom support plate 27; the vertical frame 32 is fixedly arranged on the cantilever plate 31; the driving screw rod 33 is rotatably arranged on the vertical frame 32; the sliding seat 34 is slidably arranged on the vertical frame 32, and is threadedly connected with the driving screw rod 33; the adjustment handle 35 is fixedly arranged on the top of the driving screw rod 33; the sensor fixing frame 37 is installed on the sliding seat 34; the temperature sensor 38 is fixedly installed in the sensor fixing frame 37; two groups of adjustment slots 36 are respectively opened on the cantilever plate 31 and the sensor fixing frame 37, which are used for the cantilever plate 31 and the sensor fixing frame 37 to be fixed by bolts after the angle adjustment.

[0030] The robot arm 43 includes a base 431, a rotating servo 432, two sets of gears 433, a stabilizing frame 434, a linear rail 435, a sliding connection 436, a pneumatic telescopic rod 437, a rotating motor 438, a lifting motor 439 and a lifting screw 4310. The base 431 is fixedly arranged on the bottom support plate 27; the rotating servo 432 is fixedly arranged at the bottom of the base 431; the stabilizing frame 434 is fixedly arranged on the base 431; the linear rail 435 is rotatably arranged between the base 431 and the stabilizing frame 434; the two sets of gears 433 are rotatably arranged in the base 431, and the two sets of gears 433 The two sets of gears 433 are meshed with each other, and are fixedly connected to the output end of the rotary servo 432 and the linear rail 435 respectively; the sliding connection part 436 is slidably set on the outer wall of the linear rail 435; the pneumatic telescopic rod 437 is rotatably set on the sliding connection part 436, and a rotating motor 438 for driving the pneumatic telescopic rod 437 to rotate is fixedly set on the sliding connection part 436; the lifting motor 439 is fixedly set on the top of the linear rail 435; the lifting screw 4310 is rotatably set on the linear rail 435, and its top end is fixedly connected to the output shaft of the lifting motor 439, and the sliding connection part 436 is threadedly connected to it.

[0031] The workpiece loading mechanism 41 includes a positioning servo motor 411 fixedly arranged at the output end of a group of pneumatic telescopic rods 437 and a clamp seat 412 rotatably arranged at the end of the pneumatic telescopic rods 437. The output end of the positioning servo motor 411 is fixedly connected to the clamp seat 412. A plurality of pneumatic clamps 413 are fixedly assembled in the clamp seat 412, and the plurality of pneumatic clamps 413 are distributed on the clamp seat 412 in an equidistant circular array. The workpiece loading mechanism 41 also includes three groups of conveyor belts 414, and the three groups of conveyor belts 414 are arranged side by side under the pneumatic telescopic rods 437.

[0032] The solder paste coating mechanism 42 includes a solder paste nozzle 421 fixedly arranged at the output end of another set of pneumatic telescopic rods 437 and a solder paste heating chamber 423 fixedly arranged on one side of the bottom support plate 27. A hose pump 424 is installed on the top of the solder paste heating chamber 423. A material guide pipe 422 is installed between the solder paste nozzle 421 and the hose pump 424. A metering pump is installed on the material guide pipe 422, and an electric heating insulation sleeve is installed on the outer wall of the material guide pipe 422.

[0033] Working principle: When the device is in use, the upper mold 22 and the lower mold 24 are first preheated by the welding machine 21, and the upper mold 22 and the lower mold 24 are electrically heated by respectively setting electric heating wires in the upper mold 22 and the lower mold 24, and the current loop is designed at the same time, so as to achieve the purpose of preheating, and at the same time, the leveling seat 234 is abutted against the leveling hemisphere 233, and at the same time, the top bolt 235 and the tension bolt 236 are rotated, so that the connecting plate 232 is leveled at the bottom of the movable plate 231; Then, workpiece A and workpiece B are placed on the conveyor belt 414 for loading, and solder paste is added inside the solder paste heating chamber 423. At this time, by starting the loading robot, the rotary servo 432 on this side drives the linear rail 435 to rotate in the stable frame 434 through the gear 433. At the same time, the lifting motor 439 drives the lifting screw 4310 to rotate, so that the sliding connection part 436 moves up and down along the linear rail 435, and then the pneumatic telescopic rod 437 is controlled to be extended and retracted, thereby realizing multi-dimensional adjustment of the clamp seat 412. At this time, the pneumatic clamp 413 on the clamp seat 412 is used to clamp a The servo motor 411 is rotated to adjust the direction of the pneumatic clamps 413, and then the next group of pneumatic clamps 413 are used to clamp the next group of workpieces, so that a single clamp seat 412 can clamp multiple workpieces at the same time, and then a group of workpieces is placed on the preheated lower mold 24 through the pneumatic clamps 413, and then another group of mechanical arms 43 drives the solder paste nozzle 421 to move to the top of the workpiece for solder paste coating, and then another group of workpieces is placed through the pneumatic clamps 413, so as to realize the standard automatic loading of workpieces and solder paste, and the whole process is positioned by the visual module 5; After the workpiece is loaded, the control host 12 controls the drive cylinder 26 to start, so that the upper mold 22 moves downward, and the workpiece is pressurized by the upper mold 22 and the lower mold 24. At the same time, a pulsating current is introduced so that the current flows through the workpiece. At this time, the workpiece begins to heat up under the action of its own resistance, thereby realizing resistive diffusion brazing. After the welding is completed, the upper mold 22 is reset, and then the welded workpiece is taken away by the loading robot, thereby completing the entire welding operation.

[0034] Embodiment 2 The embodiment of the invention discloses a control system of a resistance diffusion brazing device.

[0035] According to the attached Figure 1-11 As shown, based on the first embodiment, the following steps are also included: Step 1: Start the machine and level the upper mold; Step 2: The welding machine 21 preheats the upper mold 22 and the lower mold 24; Step 3: Monitor the temperature of the lower mold 24 through the temperature sensor 38 and set the temperature threshold H1. When the temperature reaches H1, start loading the workpiece through the loading unit 4. Step 4: The upper mold 22 moves downward to pre-press the workpiece on the lower mold 24. The pre-pressing is divided into two stages. The pressure value of the first stage is 2Mpa, and the pre-pressing time is 5s. Then the pressure is increased to 3Mpa in the second stage, and then the pressure is maintained. Step 5: Set the temperature threshold H2 and the pressure threshold P3, P3<3Mpa, detect the temperature on the mold side, when the temperature reaches H2, reduce the pressure to P3, and then apply pulsating direct current to the workpiece to heat it using the workpiece's own resistance; Step 6: Set the temperature threshold H3 and the pressure threshold P4. When the mold temperature reaches H3, start the pressure ramp program, slowly increase the pressure from P3 to P4, and then maintain the pressure for 2 seconds. Step seven, the upper mold 22 moves upward and resets, and the workpiece unloading starts through the loading unit 4.

[0036] The process of loading and unloading materials by the loading unit 4 in step 3 and step 7 includes: S1, the loading robot grabs workpiece A and workpiece B from the conveyor belt 414 for loading, where the number of workpiece A>1, the number of workpiece B=1, the robot vacancy ≥1, and the solder paste robot preheats the solder paste; S2, using the visual module 5 to detect whether there is material on the lower mold 24, if there is material, the material is taken away by the loading robot, and if there is no material on the lower mold 24, the workpiece A is placed on the lower mold 24 by the loading robot; S3, positioning the workpiece A on the lower mold 24 through the visual module 5, and then applying solder paste by the solder paste robot; S4, the visual module 5 detects whether there is solder paste on the workpiece A. If not, the machine stops and reports an error. The maintenance personnel detect whether it is an error in the visual module 5 that causes the solder paste coating position to be wrong; or a fault in the solder paste robot that causes the paste to be unable to be dispensed; if there is solder paste on the workpiece A, the next step is to make a judgment; S5. When solder paste exists on workpiece A, it is determined whether the solder paste is pressed. If so, the workpiece A is taken away by the loading robot, and then the lower mold 24 is repositioned to place a new workpiece A. If not, the next step of determination is performed. S6. If the solder paste on workpiece A is not pressed, the solder paste coverage area ratio S on workpiece A is detected, and the area ratio thresholds Smin=60% and Smax=85% are set to determine whether Smin<S<Smax is established. If S is not in this interval, the workpiece A is taken away by the loading robot, and then a new workpiece A is placed. If S is in this interval, the next step of determination is performed; S7. When Smin<S<Smax holds true, the amount of solder paste added is obtained through a metering pump, and the average solder paste thickness L is calculated based on the amount added and the proportion of the solder paste area. The thickness thresholds Lmin=0.12mm and Lmax=0.15mm are set, and then a judgment is made. If L is within this range, the position of workpiece A is located through the visual module 5, and workpiece B is placed on workpiece A through the loading robot. Then, the loading robot places the finished workpiece and workpiece A that failed to be coated with solder paste on two conveyor belts 414 for unloading, respectively. At this time, loading is completed and the welding process is waiting to end.

[0037] Working principle: In this embodiment, a control method for a resistance diffusion brazing device is provided. In this method, a temperature sensor 38 is provided to monitor the temperature of the workpiece. At the same time, a built-in temperature monitoring module and a pressure monitoring module are provided in the upper mold 22 and the lower mold 24. The temperature monitoring module is used to control the temperature of the upper mold 22 and the lower mold 24 during the preheating process. At the same time, the pressure monitoring module is used to control the pressure during the pressure application process of the workpiece. At the same time, the temperature of the workpiece is monitored in real time by the temperature sensor 38, so as to ensure that the actual temperature and pressure are carefully controlled during the processing process to avoid the temperature and pressure not reaching the preset value due to external factors, thereby affecting the welding effect. In addition, by preheating the upper mold 22 and the lower mold 24, a pressure ramp program is used during the welding process of the workpiece so that the pressure can be slowly fed to ensure that the solder paste can be evenly diffused and metallurgically bonded with the interface of the workpiece base material during the workpiece welding process, thereby ensuring the quality of the welding surface. Secondly, it is particularly prominent that in the process of loading and unloading workpieces, a loading and unloading method is specifically designed to control the entire loading unit 4. First, a loading robot grabs multiple workpieces A and one workpiece B from the conveyor belt 414 used for loading. At the same time, the solder paste is heated inside the solder paste heating chamber 423 so that the powdered solder and the solvent are effectively mixed to form a paste. Then, the lower mold 24 is positioned by the visual module 5. If there is a processed workpiece on the lower mold 24, the pneumatic clamp 413 is used to pick up the workpiece through the empty space reserved on the clamp seat 412, and then the workpiece A is placed on the lower mold 24. At this time, the visual module 5 is used for positioning, and the solder paste is applied to the workpiece A through the solder paste nozzle 421. And through the visual module 5 and the precise calculation scheme, the solder paste in-situ detection and the solder paste edge pressing detection are carried out in turn; Then, the solder paste coating area ratio detection is performed. In this process, the number of pixels of the workpiece A area is obtained as M1, and the number of pixels of the solder paste pattern is obtained as M2 according to the color difference between the workpiece A and the solder paste through the visual module 5. The solder paste coating area ratio is calculated through the area ratio calculation formula, and then compared with the preset threshold range. When Smin<S<Smax, it is determined that the solder paste coating area is qualified, and the next step is performed. Otherwise, the workpiece A that failed to be coated is removed by the empty pneumatic clamp 413 on the feeding robot, and the solder paste is re-coated until a workpiece A with a qualified solder paste coating area is obtained. Combined with the known area of ​​workpiece A and the proportion S of solder paste area, the solder paste area is calculated, and then the solder paste pumping amount given by the metering pump is used to measure the thickness of the overall solder paste. Then, through the comparison of the solder paste thickness threshold, when the solder paste thickness L is between 0.12mm and 0.15mm, it is determined to be an effective solder paste thickness. If it does not meet the requirements, the workpiece A that failed to be coated is removed by the empty pneumatic clamp 413 on the loading robot, and the solder paste is re-coated until a workpiece A with a qualified solder paste coating thickness is obtained. Then, the workpiece B is placed on the workpiece A by the loading robot. Only then is the effective workpiece loading completed. In this process, on the one hand, the loading is performed by machinery instead of manual loading, which is fast, and the positioning is accurate by using the visual module 5. On the other hand, through a strict solder paste coating judgment process, it is ensured that the solder paste coating between the two workpieces to be welded meets the welding standard, and the situation that the welding effect does not meet the standards due to the solder paste coating not meeting the standards is avoided.

[0038] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A resistance diffusion brazing device, characterized in that: include: Control unit (1); A welding unit (2), comprising a welding machine (21) and an upper mold (22) and a lower mold (24) arranged opposite to each other; A loading unit (4), comprising a loading robot and a solder paste robot, the loading robot comprising a robot arm (43) disposed on one side of the lower mold (24) and a workpiece loading mechanism (41) mounted on the robot arm (43), and the solder paste robot comprising a robot arm (43) disposed on the other side of the lower mold (24) and a solder paste coating mechanism (42) mounted on the robot arm (43); A monitoring unit, comprising a temperature monitoring mechanism (3) and a visual module (5); The welding machine (21) monitors the temperatures of the upper mold (22), the lower mold (24) and the workpiece through a temperature monitoring mechanism (3), thereby welding the workpiece; The loading unit (4) monitors the state of the workpiece on the surface of the lower mold (24) through the visual module (5), thereby loading and unloading the workpiece.

2. A resistance diffusion brazing device according to claim 1, characterized in that: The control unit (1) comprises a frame and a control host (12) installed in the frame, the welding machine (21) is installed inside the frame, a support column (25) is fixedly arranged outside the frame, the lower mold (24) is fixedly arranged at the bottom end of the support column (25), the upper mold (22) is slidably arranged on the support column (25), a fixed carrier plate (28) is fixedly arranged at the top end of the support column (25), a driving cylinder (26) is installed at the top end of the fixed carrier plate (28), the output end of the driving cylinder (26) is fixedly connected to the upper mold (22), and a leveling mechanism (23) is installed on the upper mold (22).

3. A resistance diffusion brazing device according to claim 2, characterized in that: The leveling mechanism (23) comprises: A movable plate (231) is slidably disposed on the outer surface of the support column (25), and the top of the movable plate is fixedly connected to the output end of the driving cylinder (26); A connecting plate (232) is arranged at the bottom of the movable plate (231), and the upper mold (22) is fixedly arranged at the bottom of the connecting plate (232); A leveling hemisphere (233) fixedly disposed in the middle of the top surface of the connecting plate (232); A leveling seat (234) is fixedly arranged in the middle of the movable plate (231) and directly opposite to the leveling hemisphere (233); A top bolt (235) is threadedly connected to the movable plate (231), and a bottom end thereof abuts against a top of the connecting plate (232); The tension bolt (236) is threadedly connected to the connecting plate (232) and movably penetrates the movable plate (231).

4. A resistance diffusion brazing device according to claim 2, characterized in that: A bottom support plate (27) is fixedly arranged on the outside of the frame, the support column (25) is fixedly arranged on the bottom support plate (27), the temperature monitoring mechanism (3) and the two sets of mechanical arms (43) are respectively arranged on both sides of the bottom support plate (27), the visual module (5) comprises a first visual camera (51) and a second visual camera (52) respectively installed on the support columns (25) on both sides, and a third visual camera (53) installed on the movable plate (231), the first visual camera (51), the second visual camera (52) and the third visual camera (53) are arranged in a triangle to form a visual cross on the lower mold (24).

5. A resistance diffusion brazing device according to claim 4, characterized in that: The temperature monitoring mechanism (3) comprises: A cantilever plate (31) mounted on the bottom support plate (27); A vertical frame (32) fixedly mounted on the cantilever plate (31); A driving screw (33) rotatably mounted on the vertical frame (32); A sliding seat (34) is slidably disposed on the vertical frame (32) and is threadedly connected to the driving screw rod (33); An adjustment handle (35) fixedly disposed on the top end of the driving screw rod (33); A sensor fixing frame (37) mounted on the sliding seat (34); A temperature sensor (38) fixedly mounted in a sensor fixing frame (37); Two groups of adjustment slots (36) are respectively provided on the cantilever plate (31) and the sensor fixing frame (37) and are used to fix the cantilever plate (31) and the sensor fixing frame (37) by bolts after adjusting the angles.

6. A resistance diffusion brazing device according to claim 4, characterized in that: The mechanical arm (43) comprises: A base (431) fixedly disposed on the bottom support plate (27); A rotation servo (432) fixedly disposed at the bottom of the base (431); A stabilizing frame (434) fixedly disposed on the base (431); A linear rail (435) rotatably disposed between the base (431) and the stabilizing frame (434); Two sets of gears (433) are rotatably disposed in the base (431), and the two sets of gears (433) are meshed with each other. The two sets of gears (433) are respectively fixedly connected to the output end of the rotary servo (432) and the linear rail (435); A sliding connection portion (436) slidably disposed on the outer wall of the linear rail (435); A pneumatic telescopic rod (437) is rotatably mounted on the sliding connection portion (436), and a rotating motor (438) is fixedly mounted on the sliding connection portion (436) for driving the pneumatic telescopic rod (437) to rotate; A lifting motor (439) is fixedly arranged on the top of the linear rail (435); The lifting screw rod (4310) is rotatably arranged on the linear rail (435), and its top end is fixedly connected to the output shaft of the lifting motor (439), and the sliding connection part (436) is threadedly connected to it.

7. A resistance diffusion brazing device according to claim 6, characterized in that: The workpiece loading mechanism (41) comprises a positioning servo motor (411) fixedly arranged at the output end of a group of pneumatic telescopic rods (437) and a fixture seat (412) rotatably arranged at the end of the pneumatic telescopic rods (437), the output end of the positioning servo motor (411) is fixedly connected to the fixture seat (412), a plurality of pneumatic clamps (413) are fixedly mounted in the fixture seat (412), and the plurality of pneumatic clamps (413) are distributed on the fixture seat (412) in an equidistant annular array, and the workpiece loading mechanism (41) further comprises three groups of conveyor belts (414), wherein the three groups of conveyor belts (414) are arranged side by side below the pneumatic telescopic rods (437).

8. The resistance diffusion brazing device according to claim 6, characterized in that: The solder paste coating mechanism (42) comprises a solder paste nozzle (421) fixedly arranged at the output end of another group of pneumatic telescopic rods (437) and a solder paste heating chamber (423) fixedly arranged on one side of the bottom support plate (27); a hose pump (424) is installed on the top of the solder paste heating chamber (423); a material guide pipe (422) is installed between the solder paste nozzle (421) and the hose pump (424); a metering pump is installed on the material guide pipe (422); and an electric heating insulation sleeve is installed on the outer wall of the material guide pipe (422).

9. A control method for a resistance diffusion brazing device according to any one of claims 1 to 8, characterized in that: The steps include: Step 1: Start the machine and level the upper mold; Step 2: The welding machine (21) preheats the upper mold (22) and the lower mold (24); Step 3: Monitor the temperature of the lower mold (24) through the temperature sensor (38), set a temperature threshold H1, and when the temperature reaches H1, start loading the workpiece through the loading unit (4); Step 4: The upper mold (22) moves downward to pre-press the workpiece on the lower mold (24). The pre-pressing is divided into two stages. The pressure value of the first stage is 2 MPa and the pre-pressing time is 5 seconds. Then, the pressure is increased to 3 MPa in the second stage, and then the pressure is maintained. Step 5: Set the temperature threshold H2 and the pressure threshold P3, P3<3Mpa, detect the temperature on the mold side, when the temperature reaches H2, reduce the pressure to P3, and then apply pulsating direct current to the workpiece to heat it using the workpiece's own resistance; Step 6: Set the temperature threshold H3 and the pressure threshold P4. When the mold temperature reaches H3, start the pressure ramp program, slowly increase the pressure from P3 to P4, and then maintain the pressure for 2 seconds. Step seven: the upper mold (22) is moved upward and reset, and the workpiece is unloaded through the loading unit (4).

10. The control method of a resistance diffusion brazing device according to claim 9, characterized in that: The process of loading and unloading materials by the loading unit (4) in step 3 and step 7 includes: S1, the loading robot grabs workpiece A and workpiece B from the conveyor belt (414) for loading, wherein the number of workpiece A>1, the number of workpiece B=1, the robot vacancy ≥1, and the solder paste robot preheats the solder paste; S2, using the visual module (5) to detect whether there is material on the lower mold (24), if there is material, the material is taken away by the loading robot, and if there is no material on the lower mold (24), the workpiece A is placed on the lower mold (24) by the loading robot; S3, positioning the workpiece A on the lower mold (24) through the visual module (5), and then applying solder paste by the solder paste robot; S4, the visual module (5) detects whether the solder paste on the workpiece A exists. If not, the machine is shut down and an error is reported. The maintenance personnel detect that the visual module (5) has an error, resulting in an error in the solder paste coating position. Or the solder paste robot fails and cannot dispense the paste; if there is solder paste on workpiece A, proceed to the next step of judgment; S5, when solder paste exists on workpiece A, it is determined whether the solder paste is pressed. If so, the workpiece A is removed by the loading robot, and then the lower mold (24) is repositioned to place a new workpiece A. If not, the next step of determination is performed; S6. If the solder paste on workpiece A is not pressed, the solder paste coverage area ratio S on workpiece A is detected, and the area ratio thresholds Smin=60% and Smax=85% are set to determine whether Smin<S<Smax is established. If S is not in this interval, the workpiece A is taken away by the loading robot, and then a new workpiece A is placed. If S is in this interval, the next step of determination is performed; S7. When Smin<S<Smax holds true, the amount of solder paste added is obtained through a metering pump, and the average solder paste thickness L is calculated based on the amount added and the solder paste area ratio. The thickness thresholds Lmin=0.12mm and Lmax=0.15mm are set, and then a judgment is made. If L is within this range, the position of workpiece A is located through the visual module (5), and workpiece B is placed on workpiece A through a loading robot. Then, the loading robot places the finished workpiece and workpiece A that failed to be coated with solder paste on two conveyor belts (414) for unloading. At this time, loading is completed and the welding process is waiting to end.

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