An automatic heating riveting device for valve pipe

Abstract

The application discloses an automatic heating riveting equipment for valve pipes, which comprises a rack, a workbench, a pipe clamping device, a riveting head, a medium-frequency induction heating coil, a driving system, a temperature detecting device, a single-chip microcomputer automatic control system and a touch display. The automatic heating riveting equipment can automatically heat the valve pipes in the riveting process, reduces the yield strength of the pipe material, improves the plasticity of the pipe material, prevents the pipe from cracking in the riveting process, effectively eliminates cracks caused by stress concentration, effectively prevents the valve pipes from cracking in the riveting process, and improves the yield of the valve pipes.

Description

Technical Field

[0001] This invention relates to the technical field of metal plastic forming equipment, and in particular to the technical field of an automatic heating and riveting device for valves and pipe fittings. Background Technology

[0002] In the manufacturing process of valves and pipe fittings, riveting equipment is required for riveting processing. Riveting is a common connection and fixing process.

[0003] Chinese patent application number CN202022124500.X discloses a pipe fitting riveting device. The frame is equipped with a rivet rod and a driving component for driving the rivet rod to move up and down. The bottom end of the rivet rod is equipped with an upper die, and the frame is equipped with an upper die positioning component. The upper die positioning component includes a fixed plate set on the frame, and the fixed plate is provided with a through mounting hole for the rivet rod to pass through. The frame is equipped with a transmission component for driving the rivet rod to move up and down. However, the method still has shortcomings. It uses a cylinder to apply pressure to the pipe fitting sleeved on the fixed rod and with the rivet in place to complete the riveting, but the suspended connection of the two pipe fittings is prone to deformation due to excessive force.

[0004] Chinese Patent Application No. CN218612693U discloses a hardware hanger riveting device, including a frame, a vibratory feeding system, a receiving and feeding system, and a riveting system. The frame is used to install the vibratory feeding system, the receiving and feeding system, and the riveting system. The vibratory feeding system is used to feed and transfer the hardware hanger to the receiving and feeding system. The receiving and feeding system is used to receive the hardware hanger fed and transferred by the vibratory feeding system and to transfer the hardware hanger to the riveting system. The riveting system rivets the hardware hanger transferred by the receiving and feeding system onto a density board. However, this method still has shortcomings. During riveting, pressure is applied directly to the riveted parts in one go, which cannot disperse and transfer the stress around the riveting point. This leads to local stress concentration on the riveted parts, resulting in cracks and affecting the strength and durability of the riveted parts.

[0005] Traditional cold riveting processes have the following drawbacks: existing processing methods suffer from uneven heating, inaccurate temperature control, low efficiency, or damage to non-riveting areas. At the moment of riveting, enormous pressure is concentrated near the riveting point, causing high stress concentration in that area. This instantaneous high stress can easily cause cracks in the workpiece, resulting in product scrap, low yield, and high production costs. Summary of the Invention

[0006] The purpose of this invention is to solve the problems in the prior art and to propose an automatic heating and riveting device for valve fittings, which can effectively prevent valve fittings from cracking due to stress concentration during the riveting process and improve the yield of valve fittings.

[0007] To achieve the above objectives, this invention proposes an automatic heating and riveting device for valve fittings, comprising a frame, a worktable, a fitting clamping device, a riveting head, a medium-frequency induction heating coil, a drive system, a temperature detection device, a microcontroller automatic control system, and a touch screen display. The frame is equipped with a worktable, and the fitting clamping device is mounted on the worktable. A riveting head is positioned above the fitting clamping device, and a medium-frequency induction heating coil is located at the lower part of the riveting head. The top of the riveting head is connected to the drive system, and the top of the drive system is fixedly mounted on the upper part of the frame. Several temperature detection devices are arranged around the riveting head on the side of the frame. A microcontroller automatic control system is installed inside the frame, and is connected to the drive system, the medium-frequency induction heating coil, and the temperature detection devices. A touch screen display is located on the side of the frame and is connected to the microcontroller automatic control system.

[0008] Preferably, the pipe clamping device includes a fixed base, a lead screw, an adjusting knob, a movable clamping block, and an anti-slip rubber pad. The fixed base is fixedly mounted on the workbench, and the lead screw is mounted on the fixed base. One end of the lead screw is connected to the adjusting knob, and the other end of the lead screw is connected to the movable clamping block. An anti-slip rubber pad is provided on the inner side of the movable clamping block.

[0009] Preferably, the drive system includes a servo hydraulic cylinder, which is vertically mounted on the upper part of the frame. The piston rod of the servo hydraulic cylinder is connected to a riveting head. A medium-frequency induction heating coil is fixedly mounted on the outer side of the lower end of the riveting head through an insulating bracket. The medium-frequency induction heating coil is in an insulated contact or non-contact state with the riveting head and valve fittings. When the valve fittings are fed into the fitting clamping device, the riveting point is located within the magnetic field range of the medium-frequency induction heating coil.

[0010] Preferably, the temperature detection device is an infrared thermometer, which is fixed to the side wall of the frame body by a bracket, and the detection end of the temperature detection device is directly facing the riveting point of the valve fitting.

[0011] Preferably, the microcontroller-based automatic control system uses an STC89C52 microcontroller as its core, and is equipped with a minimum system circuit, a watchdog circuit, and a PWM control circuit. The minimum system circuit includes a reset circuit and a clock circuit. The reset circuit includes a push-button switch S1, an energy storage capacitor C1, and a pull-down resistor R1. The clock circuit includes a crystal oscillator U2 and filter capacitors C2 and C3.

[0012] Preferably, the microcontroller-based automatic control system is electrically connected to the IGBT module via a drive circuit module, and the IGBT module is electrically connected to the intermediate frequency induction heating coil. The drive circuit module includes a drive chip with electrical isolation, a current-limiting resistor R5, and a power amplifier push-pull circuit composed of complementary transistors. The drive chip receives the PWM speed control signal output by the microcontroller-based automatic control system, and after being amplified by the push-pull circuit, it is connected to the gate of the IGBT module through a gate-on resistor R6 and a gate-off resistor R7 to control the high-frequency current switching frequency of the intermediate frequency induction heating coil.

[0013] Preferably, the driver chip with electrical isolation function is a TLP5214 chip, and the push-pull circuit is connected to a +15V turn-on voltage and a -9V turn-off negative voltage, respectively.

[0014] Preferably, the touch display includes an LCD1602 liquid crystal display module and a button control module; the button control module is used to set the target heating temperature, the heat preservation time and the heating output time, and the LCD1602 liquid crystal display module is used to display the current measured temperature, the set temperature and the working status of the device in real time. Pins 7-14 of the LCD1602 liquid crystal display module are connected in parallel to the data port of the STC89C52 microcontroller, and pin 3 is connected through a voltage divider circuit composed of resistors R4 and R5.

[0015] Preferably, the microcontroller automatic control system monitors the real-time temperature data of the temperature detection device, and adjusts the output power of the medium-frequency induction heating coil through a PID algorithm based on the difference between the real-time temperature data and the preset target temperature. When the real-time temperature data reaches the preset target temperature, the control drive system drives the riveting head downward to complete the riveting action.

[0016] Preferably, when the real-time temperature approaches the preset target temperature, the microcontroller automatic control system automatically adjusts the duty cycle of the PWM signal to reduce the heating power and enters the constant temperature holding stage; after the constant temperature holding time reaches the set value, the drive system is then controlled to drive the riveting head downward for riveting.

[0017] The beneficial effects of this invention are as follows: This invention can automatically heat valve fittings locally during the riveting process, reducing the yield strength of the fitting material and increasing its plasticity, making the fitting less prone to cracking during riveting. It effectively eliminates cracks caused by stress concentration. The movable clamping block is connected to an adjusting knob via a lead screw. Rotating the lead screw moves the movable clamping block, thereby clamping the fitting. An anti-slip rubber pad is affixed to the inner surface of the movable clamping block, preventing displacement of the workpiece under high riveting pressure and avoiding damage to the workpiece surface. The push-pull circuit is connected to a +15V turn-on voltage and a -9V turn-off negative voltage to ensure the reliability of the IGBT module during induction heating. The output of the push-pull circuit is connected to the gate of the IGBT through an asymmetrically set gate-on resistor R6 and gate-off resistor R7, thereby precisely controlling the intermediate frequency induction heating. The high-frequency current switching frequency of the heating coil is controlled by IGBT, and the heating power is adjusted by changing the PWM duty cycle. The system also includes a watchdog circuit for automatic microcontroller reset to ensure safe operation of the equipment under high temperature and high pressure. The LCD1602 liquid crystal display circuit can display two lines, each with 16 characters. It has the advantages of small size, low energy loss, and clear content. This circuit is connected to the microcontroller's data port through pins 7-14 to achieve parallel data transmission. Pin 3 is connected through a voltage divider circuit composed of resistors R4 and R5 to fix the contrast, ensuring that the equipment can clearly read the real-time temperature data fed back by the infrared thermometer in the complex environment of the riveting station. This effectively prevents valves and fittings from cracking due to stress concentration during the riveting process and improves the yield rate of valves and fittings.

[0018] The features and advantages of the present invention will be described in detail through embodiments and in conjunction with the accompanying drawings. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the main structure of an automatic heating and riveting device for valve fittings according to the present invention; Figure 2 This is the minimum system circuit diagram of an STC89C52 microcontroller for an automatic heating and riveting device for valves and pipe fittings according to the present invention. Figure 3 This is a flowchart of the PID algorithm for a microcontroller used in an automatic heating and riveting device for valves and pipe fittings according to the present invention. Figure 4 This is a block diagram illustrating the hardware circuit design principle of an automatic heating and riveting device for valves and pipe fittings according to the present invention. Figure 5 This is a display circuit diagram of an automatic heating and riveting device for valve fittings according to the present invention.

[0020] In the diagram: 1-frame, 2-workbench, 3-pipe clamping device, 4-riveting head, 5-medium frequency induction heating coil, 6-drive system, 7-temperature detection device, 8-single-chip microcomputer automatic control system, 9-touch display, 10-fixed base, 11-lead screw, 12-adjusting knob, 13-movable clamping block, 14-anti-slip rubber pad. Detailed Implementation

[0021] Example 1 See Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5This invention discloses an automatic heating and riveting device for valve fittings, comprising a frame 1, a workbench 2, a fitting clamping device 3, a riveting head 4, a medium-frequency induction heating coil 5, a drive system 6, a temperature detection device 7, a single-chip microcomputer automatic control system 8, and a touch screen display 9. The workbench 2 is mounted on the frame 1, and the fitting clamping device 3 is mounted on the workbench 2. The riveting head 4 is positioned above the fitting clamping device 3, and the medium-frequency induction heating coil 5 is positioned below the riveting head 4. The drive system 6 is connected to the top of the riveting head 4, and the top of the drive system 6 is fixedly mounted on the upper part of the frame 1. Several temperature detection devices 7 are arranged around the riveting head 4 on the side of the frame 1. The single-chip microcomputer automatic control system 8 is housed inside the frame 1, and is connected to the drive system 6, the medium-frequency induction heating coil 5, and the temperature detection devices 7 respectively. The touch screen display 9 is located on the side of the frame 1 and is connected to the single-chip microcomputer automatic control system 8. The drive system 6 includes a servo hydraulic cylinder, which is vertically mounted on the upper part of the frame 1. The piston rod of the servo hydraulic cylinder is connected to a riveting head 4. A medium-frequency induction heating coil 5 is fixedly mounted on the lower outer side of the riveting head 4 through an insulating bracket. The medium-frequency induction heating coil 5 is in an insulated contact or non-contact state with the riveting head 4 and the valve fitting. When the valve fitting is sent into the fitting clamping device 3, the riveting point is located within the magnetic field range of the medium-frequency induction heating coil 5. The microcontroller automatic control system 8 uses an STC89C52 microcontroller as its core and is equipped with a minimum system circuit, a watchdog circuit, and a PWM control circuit. The minimum system circuit includes a reset circuit and a clock circuit. The reset circuit includes a push-button switch S1, an energy storage capacitor C1, and a pull-down resistor R1. The clock circuit includes a crystal oscillator U2 and filter capacitors C2 and C3. The microcontroller automatic control system 8 is electrically connected to the IGBT module through the drive circuit module. The IGBT module is electrically connected to the medium-frequency induction heating coil 5.The drive circuit module includes a drive chip with electrical isolation, a current-limiting resistor R5, and a power amplifier push-pull circuit composed of complementary transistors. The drive chip receives the PWM speed control signal output by the microcontroller automatic control system 8. After being amplified by the push-pull circuit, the signal is connected to the gate of the IGBT module through the gate turn-on resistor R6 and the gate turn-off resistor R7 to control the high-frequency current switching frequency of the intermediate frequency induction heating coil 5. The drive chip with electrical isolation is a TLP5214 chip. The push-pull circuit is connected to a +15V turn-on voltage and a -9V turn-off negative voltage, respectively. The automatic control system 8 monitors the real-time temperature data from the temperature detection device 7. Based on the difference between the real-time temperature data and the preset target temperature, it adjusts the output power of the intermediate frequency induction heating coil 5 using a PID algorithm. When the real-time temperature reaches the preset target temperature, the control drive system 6 drives the riveting head 4 downwards to complete the riveting action. When the real-time temperature approaches the preset target temperature, the microcontroller automatic control system 8 automatically adjusts the duty cycle of the PWM signal to reduce the heating power and enters the constant temperature holding stage. After the constant temperature holding time reaches the set value, the control drive system 6 then drives the riveting head 4 downwards for riveting.

[0022] Example 2 See Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5This invention discloses an automatic heating and riveting device for valve fittings, comprising a frame 1, a workbench 2, a fitting clamping device 3, a riveting head 4, a medium-frequency induction heating coil 5, a drive system 6, a temperature detection device 7, a single-chip microcomputer automatic control system 8, and a touch screen display 9. The workbench 2 is mounted on the frame 1, the fitting clamping device 3 is mounted on the workbench 2, the riveting head 4 is positioned above the fitting clamping device 3, the medium-frequency induction heating coil 5 is positioned below the riveting head 4, the drive system 6 is connected to the top of the riveting head 4, and the top of the drive system 6 is fixedly mounted on the upper part of the frame 1. The sides of the frame 1 are arranged around the position of the riveting head 4. There are several temperature detection devices 7. A single-chip microcomputer automatic control system 8 is installed inside the frame 1. The single-chip microcomputer automatic control system 8 is connected to the drive system 6, the intermediate frequency induction heating coil 5, and the temperature detection devices 7 respectively. A touch screen display 9 is installed on the side of the frame 1, and the touch screen display 9 is connected to the single-chip microcomputer automatic control system 8. The pipe clamping device 3 includes a fixed base 10, a lead screw 11, an adjusting knob 12, a movable clamping block 13, and an anti-slip rubber pad 14. The fixed base 10 is fixedly mounted on the workbench 2. The lead screw 11 is mounted on the fixed base 10. One end of the lead screw 11 is connected to the adjusting knob 12, and the other end of the lead screw 11... The end is connected to a movable clamping block 13, and the inner surface of the movable clamping block 13 is provided with an anti-slip rubber pad 14. The single-chip microcomputer automatic control system 8 uses an STC89C52 single-chip microcomputer as its core, and is equipped with a minimum system circuit, a watchdog circuit, and a PWM control circuit. The minimum system circuit includes a reset circuit and a clock circuit. The reset circuit includes a push-button switch S1, an energy storage capacitor C1, and a pull-down resistor R1. The clock circuit includes a crystal oscillator U2 and filter capacitors C2 and C3. The single-chip microcomputer automatic control system 8 is electrically connected to the IGBT module through a drive circuit module. The IGBT module is electrically connected to the intermediate frequency induction heating coil 5. The drive circuit... The circuit module includes a power amplifier push-pull circuit composed of a driver chip with electrical isolation, a current-limiting resistor R5, and complementary transistors. The driver chip receives the PWM speed control signal output by the microcontroller automatic control system 8. After being amplified by the push-pull circuit, the signal is connected to the gate of the IGBT module through the gate turn-on resistor R6 and the gate turn-off resistor R7 to control the high-frequency current switching frequency of the intermediate frequency induction heating coil 5. The driver chip with electrical isolation is a TLP5214 chip. The push-pull circuit is connected to a +15V turn-on voltage and a -9V turn-off negative voltage. The touch display 9 includes an LCD1602 liquid crystal display module and a button control module.The button control module is used to set the target heating temperature, holding time, and heating output time. The LCD1602 liquid crystal display module is used to display the current measured temperature, set temperature, and equipment operating status in real time. Pins 7-14 of the LCD1602 liquid crystal display module are connected in parallel to the data port of the STC89C52 microcontroller. Pin 3 is connected through a voltage divider circuit composed of resistors R4 and R5. The microcontroller automatic control system 8 monitors the real-time temperature data of the temperature detection device 7. Based on the difference between the real-time temperature data and the preset target temperature, it adjusts the output power of the intermediate frequency induction heating coil 5 through a PID algorithm. When the real-time temperature data reaches the preset target temperature, it controls the drive system 6 to drive the riveting head 4 downward to complete the riveting action. When the real-time temperature approaches the preset target temperature, the microcontroller automatic control system 8 automatically adjusts the duty cycle of the PWM signal to reduce the heating power and enter the constant temperature holding stage. After the constant temperature holding time reaches the set value, it controls the drive system 6 to drive the riveting head 4 downward to rivet.

[0023] Example 3 See Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5This invention discloses an automatic heating and riveting device for valve fittings, comprising a frame 1, a workbench 2, a fitting clamping device 3, a riveting head 4, a medium-frequency induction heating coil 5, a drive system 6, a temperature detection device 7, a single-chip microcomputer automatic control system 8, and a touch screen display 9. The workbench 2 is mounted on the frame 1, the fitting clamping device 3 is mounted on the workbench 2, the riveting head 4 is positioned above the fitting clamping device 3, the medium-frequency induction heating coil 5 is positioned below the riveting head 4, the drive system 6 is connected to the top of the riveting head 4, and the top of the drive system 6 is fixedly mounted on the upper part of the frame 1. The sides of the frame 1 are arranged around the position of the riveting head 4. There are several temperature detection devices 7. A single-chip microcomputer automatic control system 8 is installed inside the frame 1. The single-chip microcomputer automatic control system 8 is connected to the drive system 6, the intermediate frequency induction heating coil 5, and the temperature detection devices 7 respectively. A touch screen display 9 is installed on the side of the frame 1, and the touch screen display 9 is connected to the single-chip microcomputer automatic control system 8. The pipe clamping device 3 includes a fixed base 10, a lead screw 11, an adjusting knob 12, a movable clamping block 13, and an anti-slip rubber pad 14. The fixed base 10 is fixedly mounted on the workbench 2. The lead screw 11 is mounted on the fixed base 10. One end of the lead screw 11 is connected to the adjusting knob 12, and the other end of the lead screw 11... The drive system 6 includes a servo hydraulic cylinder, which is vertically mounted on the upper part of the frame 1. A riveting head 4 is connected to the piston rod end of the servo hydraulic cylinder. A medium-frequency induction heating coil 5 is fixedly mounted on the outer side of the lower end of the riveting head 4 via an insulating bracket. The medium-frequency induction heating coil 5 is in an insulated contact or non-contact state with the riveting head 4 and the valve fittings. When the valve fittings are fed into the fitting clamping device 3, the riveting point is located within the magnetic field range of the medium-frequency induction heating coil 5. The temperature detection device 7 is an infrared thermometer. The temperature detection device 7 is fixed to the side wall of the frame 1 body by a bracket. The detection end of the temperature detection device 7 is directly facing the riveting point of the valve fitting. The microcontroller automatic control system 8 uses an STC89C52 microcontroller as its core and is equipped with a minimum system circuit, a watchdog circuit, and a PWM control circuit. The minimum system circuit includes a reset circuit and a clock circuit. The reset circuit includes a push-button switch S1, an energy storage capacitor C1, and a pull-down resistor R1. The clock circuit includes a crystal oscillator U2 and filter capacitors C2 and C3. The microcontroller automatic control system 8 is electrically connected to the IGBT module through a drive circuit module. The IGBT module is electrically connected to the medium frequency induction heating coil 5.The drive circuit module includes a drive chip with electrical isolation, a power amplifier push-pull circuit composed of a current-limiting resistor R5 and complementary transistors. The drive chip receives the PWM speed control signal output by the microcontroller automatic control system 8. After being amplified by the push-pull circuit, the signal is connected to the gate of the IGBT module through the gate turn-on resistor R6 and the gate turn-off resistor R7 to control the high-frequency current switching frequency of the intermediate frequency induction heating coil 5. The drive chip with electrical isolation is a TLP5214 chip. The push-pull circuit is connected to a +15V turn-on voltage and a -9V turn-off negative voltage. The touch display 9 includes an LCD1602 liquid crystal display module and a button control module. The button control module is used to set the target heating temperature, heat preservation time, and heating output time. The LCD1602 liquid crystal display module is used to display the current measured temperature, set temperature, and equipment operating status in real time. Pins 7-14 of the LCD1602 liquid crystal display module are connected to the STC89C52 microcontroller. The microcontroller's data ports are connected in parallel. Pin 3 is connected via a voltage divider circuit composed of resistors R4 and R5. The microcontroller-based automatic control system 8 monitors the real-time temperature data from the temperature detection device 7. Based on the difference between the real-time temperature data and the preset target temperature, it adjusts the output power of the intermediate frequency induction heating coil 5 using a PID algorithm. When the real-time temperature reaches the preset target temperature, the drive system 6 drives the riveting head 4 downwards to complete the riveting action. When the real-time temperature approaches the preset target temperature, the microcontroller-based automatic control system 8 automatically adjusts the duty cycle of the PWM signal to reduce the heating power and enters the constant temperature holding stage. After the constant temperature holding time reaches the set value, the drive system 6 then drives the riveting head 4 downwards for riveting.

[0024] In the operation of this invention, the valve fitting to be riveted is placed in the fitting clamping device 3, the screw 11 is tightened, and the anti-slip rubber pad 14 secures the valve fitting; the preheating temperature is set by pressing the button; the target suitable temperature range is set through the button control circuit; the start button is pressed, the infrared thermometer starts working, collects the initial temperature of the riveting point of the workpiece and transmits it to the STC89C52 microcontroller; the microcontroller instructs the IGBT module to conduct, and the intermediate frequency induction heating coil 5 starts full-power heating. During the heating process, the microcontroller continuously compares the real-time temperature with the preset target temperature. When the real-time temperature approaches the preset value, the microcontroller automatically adjusts the duty cycle of the PWM signal, reduces the heating power, and enters the constant temperature holding stage to prevent temperature overshoot from causing the valve fitting to melt or become too soft; when the temperature stabilizes and reaches the preset value, the microcontroller sends an instruction to the servo hydraulic cylinder, which drives the riveting head 4 to descend rapidly; after riveting is completed, the servo hydraulic cylinder drives the riveting head 4 to move upward and reset, heating stops, and the LCD1602 liquid crystal display module indicates that the processing is complete.

[0025] This invention enables localized automatic heating of valve fittings during the riveting process, reducing the yield strength of the fitting material and increasing its plasticity. This makes the fittings less prone to cracking during riveting, effectively eliminating cracks caused by stress concentration, and effectively preventing valve fittings from cracking due to stress concentration during the riveting process, thereby improving the yield rate of valve fittings.

[0026] The above embodiments are illustrative of the present invention and are not intended to limit the present invention. Any simple modifications to the present invention are within the scope of protection of the present invention.

Claims

1. An automatic heating and riveting device for valves and pipe fittings, characterized in that: The system includes a frame (1), a workbench (2), a pipe clamping device (3), a riveting head (4), a medium-frequency induction heating coil (5), a drive system (6), a temperature detection device (7), a single-chip microcomputer automatic control system (8), and a touch screen display (9). The workbench (2) is mounted on the frame (1), the pipe clamping device (3) is mounted on the workbench (2), the riveting head (4) is mounted above the pipe clamping device (3), the medium-frequency induction heating coil (5) is mounted on the lower part of the riveting head (4), and the drive system (6) is connected to the top of the riveting head (4). The system (6) is fixedly mounted on the top of the drive system (6) on the upper part of the frame (1). Several temperature detection devices (7) are arranged around the riveting head (4) on the side of the frame (1). A single-chip microcomputer automatic control system (8) is arranged inside the frame (1). The single-chip microcomputer automatic control system (8) is connected to the drive system (6), the medium frequency induction heating coil (5) and the temperature detection devices (7) respectively. A touch screen display (9) is arranged on the side of the frame (1). The touch screen display (9) is connected to the single-chip microcomputer automatic control system (8).

2. The automatic heating and riveting equipment for valve fittings as described in claim 1, characterized in that: The pipe clamping device (3) includes a fixed seat (10), a lead screw (11), an adjustment knob (12), a movable clamping block (13), and an anti-slip rubber pad (14). The fixed seat (10) is fixedly mounted on the workbench (2). The lead screw (11) is mounted on the fixed seat (10). One end of the lead screw (11) is connected to the adjustment knob (12), and the other end of the lead screw (11) is connected to the movable clamping block (13). An anti-slip rubber pad (14) is mounted on the inner side of the movable clamping block (13).

3. The automatic heating and riveting equipment for valves and pipe fittings as described in claim 1, characterized in that: The drive system (6) includes a servo hydraulic cylinder, which is vertically mounted on the upper part of the frame (1). The piston rod of the servo hydraulic cylinder is connected to a riveting head (4). A medium-frequency induction heating coil (5) is fixedly installed on the lower outer side of the riveting head (4) through an insulating bracket. The medium-frequency induction heating coil (5) is in an insulated contact or non-contact state with the riveting head (4) and the valve fittings. When the valve fittings are sent into the fitting clamping device (3), the riveting point is located within the magnetic field range of the medium-frequency induction heating coil (5).

4. The automatic heating and riveting equipment for valves and pipe fittings as described in claim 1, characterized in that: The temperature detection device (7) is an infrared thermometer. The temperature detection device (7) is fixed to the side wall of the frame (1) body by a bracket. The detection end of the temperature detection device (7) is facing the rivet point of the valve fitting.

5. An automatic heating and riveting device for valve fittings as described in claim 1, characterized in that: The microcontroller automatic control system (8) uses STC89C52 microcontroller as the core and is equipped with minimum system circuit, watchdog circuit and PWM control circuit. The minimum system circuit includes a reset circuit and a clock circuit. The reset circuit includes a push button switch S1, energy storage capacitor C1 and pull-down resistor R1. The clock circuit includes crystal oscillator U2 and filter capacitors C2 and C3.

6. An automatic heating and riveting device for valve fittings as described in claim 5, characterized in that: The microcontroller automatic control system (8) is electrically connected to the IGBT module through the drive circuit module, and the IGBT module is electrically connected to the intermediate frequency induction heating coil (5). The drive circuit module includes a drive chip with electrical isolation function, a current limiting resistor R5 and a power amplifier push-pull circuit composed of complementary transistors. The drive chip receives the PWM speed regulation signal output by the microcontroller automatic control system (8), and after being amplified by the push-pull circuit, it is connected to the gate of the IGBT module through the gate opening resistor R6 and the gate closing resistor R7 to control the high frequency current switching frequency of the intermediate frequency induction heating coil (5).

7. An automatic heating and riveting device for valve fittings as described in claim 6, characterized in that: The driver chip with electrical isolation function is a TLP5214 chip, and the push-pull circuit is connected to a +15V turn-on voltage and a -9V turn-off negative voltage, respectively.

8. An automatic heating and riveting device for valve fittings as described in claim 1, characterized in that: The touch display (9) includes an LCD1602 liquid crystal display module and a button control module; the button control module is used to set the target heating temperature, heat preservation time and heating output time, and the LCD1602 liquid crystal display module is used to display the current measured temperature, set temperature and equipment working status in real time. Pins 7-14 of the LCD1602 liquid crystal display module are connected in parallel to the data port of the STC89C52 microcontroller, and pin 3 is connected through a voltage divider circuit composed of resistors R4 and R5.

9. An automatic heating and riveting device for valves and pipe fittings as described in claim 1, characterized in that: The microcontroller automatic control system (8) monitors the real-time temperature data of the temperature detection device (7). Based on the difference between the real-time temperature data and the preset target temperature, it adjusts the output power of the medium frequency induction heating coil (5) through the PID algorithm. When the real-time temperature data reaches the preset target temperature, the control drive system (6) drives the riveting head (4) to move downward to complete the riveting action.

10. An automatic heating and riveting device for valve fittings as described in claim 9, characterized in that: When the real-time temperature approaches the preset target temperature, the microcontroller automatic control system (8) automatically adjusts the duty cycle of the PWM signal to reduce the heating power and enters the constant temperature holding stage; when the constant temperature holding time reaches the set value, the drive system (6) is then controlled to drive the riveting head (4) to rivet downwards.

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