Pneumatic control circuit of circuit board turnover machine

Abstract

The invention discloses a pneumatic control circuit of a circuit board turnover machine, which comprises a plurality of triodes, a plurality of diodes, a plurality of field effect transistors and a plurality of resistors, and is characterized in that the base electrode of a triode Q1 in the plurality of triodes is connected with the cathode of a diode D2 and one end of a resistor R2, the collector electrode is connected with the anode of a diode D1 and one end of a resistor R1, and the emitter electrode is connected with the drain electrode of a field effect transistor Q3; the base electrode of the triode Q2 is connected with the cathode of the diode D1 and one end of the resistor R3, the collector electrode is connected with the anode of the diode D2 and one end of the resistor R4, and the emitter electrode is connected with the drain electrode of the field effect transistor Q4; the grid electrode of the field effect transistor Q3 is connected with the grid electrode of the field effect transistor Q4; the source end of the field effect transistor Q3 obtains a forward turning plate control signal; the source end of the field effect transistor Q4 obtains a reverse turning plate control signal; the other end of the resistor R1, the other end of the resistor R2, the other end of the resistor R3 and the other end of the resistor R4 are grounded.

Description

Technical Field

[0001] The present invention relates to the technical field of pneumatic control of panel turning machines, in particular to a pneumatic control circuit of a circuit board turning machine. Background Art

[0002] The circuit board flip machine is mainly used for double-sided patch and welding of circuit boards to ensure the processing accuracy of both sides and reduce damage and misalignment caused by manual operation. The flipping control of the circuit board is mainly achieved by charging the positive / reverse coils of the solenoid valve to make the cylinder extend / contract to complete the flipping of the circuit board. However, the existing pneumatic control circuit of the circuit board flip machine will cause the valve core in the solenoid valve to be damaged and malfunction during flipping due to the feedback of incorrect flipping control signals by the MCU or manual maintenance and debugging before and during flipping. Therefore, a pneumatic control circuit of the circuit board flip machine is proposed, which can prevent the valve core from being damaged due to the positive / reverse coils in the solenoid valve receiving power signals at the same time before flipping and the malfunction of flipping caused by the re-energization of the positive / reverse action coils in the solenoid valve during flipping, and can prevent the movement deviation of the cylinder caused by fluctuations in the air source pressure before movement. Summary of the Invention

[0003] In response to the above technical problems, the purpose of the present invention is to provide a pneumatic control circuit for a circuit board flip machine, comprising a plurality of transistors, a plurality of diodes, a plurality of field-effect transistors, and a plurality of resistors, wherein the base of the transistor Q1 among the plurality of transistors is connected to the cathode of the diode D2 and one end of the resistor R2, the collector is connected to the anode of the diode D1 and one end of the resistor R1, and the emitter is connected to the drain of the field-effect transistor Q3; the base of the transistor Q2 is connected to the cathode of the diode D1 and one end of the resistor R3, the collector is connected to the anode of the diode D2 and one end of the resistor R4, and the emitter is connected to the drain of the field-effect transistor Q4; the gate of the field-effect transistor Q3 is connected to the gate of the field-effect transistor Q4; the source end of the field-effect transistor Q3 obtains a forward flip control signal; the source end of the field-effect transistor Q4 obtains a reverse flip control signal; the other end of the resistor R1, the other end of the resistor R2, the other end of the resistor R3, and the other end of the resistor R4 are grounded.

[0004] Furthermore, it also includes a trigger U2, an operational amplifier U3, and a capacitor C1. The first pin, the fourth pin, and one end of the resistor R8 of the trigger U2 are connected to the power supply, the second pin is connected to the sixth pin and one end of the resistor R10, the third pin is connected to the output end of the operational amplifier U3, the cathode of the diode D9, and one end of the resistor R9, and the fifth pin is connected to the anode of the diode D8; the in-phase terminal of the operational amplifier U3 is connected to one end of the capacitor C1, the cathode of the diode D3, the cathode of the diode D4, and one end of the resistor R6, and the inverting terminal is connected to one end of the resistor R7 and the other end of the resistor R8; the anode of the diode D3 is connected to the anode of the diode D2; the anode of the diode D4 is connected to the anode of the diode D1; the cathode of the diode D8 is connected to the gate of the field effect transistor Q3; the anode end of the diode D9 obtains the flip completion signal; the other end of the resistor R6, the other end of the resistor R7, the other end of the resistor R9, the other end of the resistor R10, and the other end of the capacitor C1 are grounded.

[0005] Furthermore, it also includes several operational amplifiers, capacitor C2, and resistor R5. Among the several operational amplifiers, the operational amplifier U1 is connected to the cathode of the diode D5, the cathode of the diode D6, one end of the capacitor C2, and one end of the resistor R5 in the same phase, and the output is connected to the anode of the diode D7; the operational amplifier U4 is connected to the inverting end of the operational amplifier U5 in the same phase, and the output is connected to the anode of the diode D6; the inverting end of the operational amplifier U4 and the inverting end of the operational amplifier U5 obtain the gas source pressure signal; the output end of the operational amplifier U5 is connected to the anode of the diode D5; the cathode of the diode D7 is connected to the cathode of the diode D8; the other end of the capacitor C2 and the other end of the resistor R5 are grounded.

[0006] Furthermore, one end of the resistor R15 among the plurality of resistors is connected to the inverting end of the operational amplifier U4 and one end of the resistor R16, and the other end is connected to the non-inverting end of the operational amplifier U5 and one end of the resistor R14; the other end of the resistor R16 is connected to the power supply; and the other end of the resistor R14 is grounded.

[0007] Furthermore, one end of the resistor R12 among the plurality of resistors is connected to the power supply, and the other end is connected to the inverting terminal of the operational amplifier U1 and one end of the resistor R11; the other end of the resistor R11 is grounded.

[0008] Furthermore, a resistor R13 is included, one end of the resistor R13 is connected to the gate of the field effect transistor Q3, and the other end is grounded.

[0009] Furthermore, the resistor R7 is an adjustable resistor.

[0010] Furthermore, the resistor R14 and the resistor R15 are adjustable resistors.

[0011] Furthermore, the resistor R11 is an adjustable resistor.

[0012] The beneficial effects of the present invention compared with the prior art are: The present invention can prevent the valve core from being damaged due to the forward / reverse coils in the solenoid valve receiving power signals at the same time before flipping, and prevent flipping malfunctions caused by the forward / reverse action coils in the solenoid valve being energized again during the flipping process, and can prevent movement deviation of the cylinder caused by fluctuations in the air source pressure before movement. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, a brief introduction is given below to the prior art and the drawings required for use in the embodiments. 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 any creative work.

[0014] Figure 1 This is a circuit structure diagram provided by the present invention. DETAILED DESCRIPTION

[0015] In order to make the objects and advantages of the present invention more clearly understood, the present invention is described in detail below with reference to the embodiments. It should be understood that the following text is only used to describe one or several specific implementation methods of the present invention and does not strictly limit the scope of protection specifically requested by the present invention.

[0016] The present invention discloses a pneumatic control circuit for a circuit board flipping machine, comprising a plurality of transistors, a plurality of diodes, a plurality of field-effect transistors, and a plurality of resistors. The base of a transistor Q1 among the plurality of transistors is connected to the cathode of a diode D2 and one end of a resistor R2, the collector is connected to the anode of a diode D1 and one end of a resistor R1, and the emitter is connected to the drain of a field-effect transistor Q3; the base of the transistor Q2 is connected to the cathode of a diode D1 and one end of a resistor R3, the collector is connected to the anode of a diode D2 and one end of a resistor R4, and the emitter is connected to the drain of a field-effect transistor Q4; the gate of the field-effect transistor Q3 is connected to the gate of the field-effect transistor Q4; the source end of the field-effect transistor Q3 obtains a forward flipping control signal; the source end of the field-effect transistor Q4 obtains a reverse flipping control signal; the other ends of the resistor R1, the other ends of the resistor R2, the other ends of the resistor R3, and the other ends of the resistor R4 are grounded.

[0017] Specifically, it also includes a trigger U2, an operational amplifier U3, and a capacitor C1. The first pin, the fourth pin, and one end of the resistor R8 of the trigger U2 are connected to the power supply, the second pin is connected to the sixth pin and one end of the resistor R10, the third pin is connected to the output end of the operational amplifier U3, the cathode of the diode D9, and one end of the resistor R9, and the fifth pin is connected to the anode of the diode D8; the in-phase terminal of the operational amplifier U3 is connected to one end of the capacitor C1, the cathode of the diode D3, the cathode of the diode D4, and one end of the resistor R6, and the inverting terminal is connected to one end of the resistor R7 and the other end of the resistor R8; the anode of the diode D3 is connected to the anode of the diode D2; the anode of the diode D4 is connected to the anode of the diode D1; the cathode of the diode D8 is connected to the gate of the field effect transistor Q3; the anode end of the diode D9 obtains the flip completion signal; the other end of the resistor R6, the other end of the resistor R7, the other end of the resistor R9, the other end of the resistor R10, and the other end of the capacitor C1 are grounded.

[0018] Specifically, it also includes several operational amplifiers, capacitor C2, and resistor R5. Among the operational amplifiers, the operational amplifier U1 is connected to the cathode of the diode D5, the cathode of the diode D6, one end of the capacitor C2, and one end of the resistor R5 in the same phase, and the output is connected to the anode of the diode D7; the operational amplifier U4 is connected to the inverting end of the operational amplifier U5 in the same phase, and the output is connected to the anode of the diode D6; the inverting end of the operational amplifier U4 and the inverting end of the operational amplifier U5 obtain the gas source pressure signal; the output end of the operational amplifier U5 is connected to the anode of the diode D5; the cathode of the diode D7 is connected to the cathode of the diode D8; the other end of the capacitor C2 and the other end of the resistor R5 are grounded.

[0019] Specifically, one end of the resistor R15 among the plurality of resistors is connected to the inverting end of the operational amplifier U4 and one end of the resistor R16, and the other end is connected to the non-inverting end of the operational amplifier U5 and one end of the resistor R14; the other end of the resistor R16 is connected to the power supply; and the other end of the resistor R14 is grounded.

[0020] Specifically, one end of the resistor R12 among the plurality of resistors is connected to the power supply, and the other end is connected to the inverting terminal of the operational amplifier U1 and one end of the resistor R11; the other end of the resistor R11 is grounded.

[0021] Specifically, a resistor R13 is further included, one end of the resistor R13 is connected to the gate of the field effect transistor Q3, and the other end is grounded.

[0022] Specifically, the resistor R7 is an adjustable resistor.

[0023] Specifically, the resistor R14 and the resistor R15 are adjustable resistors.

[0024] Specifically, the resistor R11 is an adjustable resistor.

[0025] See attached Figure 1 The flip control signal is fed back by the MCU / personnel. IN_1 and IN_2 input the forward and reverse flip control signals respectively. When the MCU feeds back the forward flip control signal, the signal passes through the source of the field effect transistor Q3, the drain of the field effect transistor Q3, the emitter of the transistor Q1, the base of the transistor Q1, and the resistor R2 to the ground terminal. The emitter of the transistor Q1 and the base of the transistor Q1 are forward biased, the transistor Q1 is turned on, and the emitter end signal of the transistor Q1 passes through the collector of the transistor Q1. The signal at the end of resistor R1 is fed back to the solenoid valve. When the MCU feeds back the reverse flip control signal, the signal passes through the source of field effect tube Q4, the drain of field effect tube Q4, the emitter of transistor Q2, the base of transistor Q2, and resistor R3 to the ground end. The emitter of transistor Q2 and the base of transistor Q2 are forward biased, transistor Q2 is turned on, and the emitter end signal of transistor Q2 passes through the collector of transistor Q2 and resistor R4 to the ground end. The signal at the end of resistor R4 is fed back to the solenoid valve. Feedback is sent to the solenoid valve. The solenoid valve is equipped with a forward-acting coil and a reverse-acting coil. When either coil is energized for a short time, the solenoid valve spool switches to the corresponding position, the cylinder moves accordingly, and the circuit board flips. The signals at the resistor R1 and resistor R4 are coil energization signals. When the solenoid valve receives the signal feedback from the resistor R1, the forward-acting coil is energized. When the solenoid valve receives the signal feedback from the resistor R4, the reverse-acting coil is energized. When the circuit receives the forward flip control signal, the signal at the resistor R1 is synchronously fed back to the base of the transistor Q2 via the diode D1, so that the transistor Q2 cannot be turned on. When the circuit receives the reverse flip control signal, the signal at the resistor R4 is synchronously fed back to the base of the transistor Q1 via the diode D2, so that the transistor Q1 cannot be turned on. In this way, the solenoid valve can only receive one of the energization signals, preventing the MCU / personnel from simultaneously feeding back the forward and reverse flip control signals, causing the forward and reverse action coils in the solenoid valve to receive energization signals at the same time and damage the valve spool.

[0026] The power supply signal passes through resistors R8 and R7 to the ground terminal. The amplitude of the signal at the resistor R7 terminal is the required power-on time of the coil. Adjust the resistance value of resistor R7 according to the solenoid valve model to set the required power-on time. The signal at the resistor R7 terminal is fed back to the inverting terminal of the op amp U3, and the signal at the capacitor C1 terminal is fed back to the non-inverting terminal of the op amp U3. When the signal at the resistor R1 terminal is fed back to the solenoid valve, the signal at the resistor R1 terminal causes the potential of the capacitor C1 terminal to rise through the diode D4. When the signal at the resistor R4 terminal is fed back to the solenoid valve, the signal at the resistor R4 terminal causes the potential of the capacitor C1 terminal to rise through the diode D3. When the potential of the capacitor C1 terminal rises and is high When the signal amplitude at the resistor R7 end is high, one of the coils in the solenoid valve has obtained the required power-on time, the solenoid valve core completes the corresponding switching, the cylinder begins to extend / contract, the circuit board begins to flip, and at the same time, the operational amplifier U3 outputs, and the output signal of the operational amplifier U3 is fed back to the 3-pin of the trigger U2. The 5-pin of the trigger U2 outputs a high level. The 5-pin signal of the trigger U2 is fed back to the gate of the field effect transistor Q3 and the gate of the field effect transistor Q4 after passing through the diode D8. The voltage difference between the gate of the field effect transistor Q3 and the source of the field effect transistor Q3 is higher than the conduction threshold, and the field effect transistor Q3 is cut off. The voltage difference between the gate of FET Q4 and the source of FET Q4 is higher than the conduction threshold, FET Q4 is cut off, FET Q3 and FET Q4 are cut off, which can limit the circuit from obtaining any flip-plate control signal fed back by MCU / personnel. At the same time, the signal at capacitor C1 is connected to the ground terminal through resistor R6, and the potential at capacitor C1 drops. When the potential at capacitor C1 drops and is lower than the signal at resistor R7, op amp U3 is cut off. Resistor R13 is the parasitic capacitance bleeder resistor of FET Q3 gate and FET Q4 gate. Resistor R9 is the 3-pin pull-down resistor of trigger U2. Resistor R1 0 is the pull-down resistor of pins 2 and 6 of trigger U2, and IN_3 inputs the flip completion signal. This signal is fed back by the MCU / personnel after the circuit board is flipped. The flip completion signal is fed back to pin 3 of trigger U2 through diode D9, and trigger U2 is reset to the initial state. Pin 5 of trigger U2 is low, and field effect transistors Q3 and Q4 are turned on. This limits the circuit from obtaining any flip control signal feedback before the circuit board is flipped, and cancels the restriction after the flip is completed to prevent the forward / reverse action coil from being energized again when the flip is not in place and causing a flip malfunction.

[0027] The upper limit signal of the gas source pressure standard is input to the inverting terminal of the operational amplifier U4, and the lower limit signal of the gas source pressure standard is input to the non-inverting terminal of the operational amplifier U5. The upper and lower limit signals of the gas source pressure standard range can be fed back by the power supply signal. IN_4 inputs the current gas source pressure signal, and the gas source pressure signal is fed back by the pressure sensor. The power supply signal passes through resistors R16, R15, and R14 to the ground terminal. The signal at the resistor R15 end is fed back to the inverting terminal of the operational amplifier U4, and the signal at the resistor R14 end is fed back to the non-inverting terminal of the operational amplifier U5. Adjust the resistance values ​​of resistors R14 and R15 to set the upper and lower limit signals of the gas source pressure standard. When the gas source pressure When the pressure fluctuates and exceeds the upper limit of the pressure standard, the operational amplifier U4 outputs, and the signal at the output of the operational amplifier U4 passes through the diode D6 and the resistor R5 to the ground terminal, and the potential of the capacitor C2 rises. When the gas source pressure fluctuates and falls below the lower limit of the pressure standard, the operational amplifier U5 outputs, and the signal at the output of the operational amplifier U5 passes through the diode D5 and the resistor R5 to the ground terminal, and the potential of the capacitor C2 rises. The signal at the capacitor C2 terminal is fed back to the non-inverting terminal of the operational amplifier U1, and the reference signal is input to the inverting terminal of the operational amplifier U1. The reference signal can be fed back by the power supply signal, and the power supply signal passes through the resistor R12 and the resistor R11 to the ground terminal. The signal at the resistor R11 terminal is the reference signal. Refer to the signal, adjust the resistance of resistor R11 to set the reference signal amplitude, the signal at the resistor R11 end is fed back to the inverting end of the operational amplifier U1, when the gas source pressure fluctuates outside the standard range and causes the potential at the capacitor C2 end to rise to a value higher than the reference signal amplitude, the operational amplifier U1 outputs, and the signal at the output end of the operational amplifier U1 is fed back to the gate of the field effect transistor Q3 and the gate of the field effect transistor Q4 through the diode D7, and the gate of the field effect transistor Q3 and the gate of the field effect transistor Q4 are cut off, when the gas source pressure is stable within the standard range, the signal at the capacitor C2 end is fed to the ground end through the resistor R5, and the potential of the capacitor C2 drops. When the potential of the capacitor C2 drops and is lower than the reference When the signal amplitude is high, the op amp U1 is cut off, and the field effect transistors Q3 and Q4 are turned on. By adjusting the reference signal amplitude, the required stabilization time for the gas source pressure to enter the standard range after the fluctuation can be adjusted. The lower the reference signal amplitude, the longer the required stabilization time. In this way, when the gas source pressure fluctuates, the circuit is limited to obtain the flap control signal to prevent the cylinder from moving when the gas source pressure fluctuates and causing movement deviation. After the gas source pressure fluctuates and the time it takes to enter the pressure standard range exceeds the required stabilization time, the restriction on the acquisition of the flap control signal is cancelled to reduce the movement of the cylinder when the gas source pressure fluctuates instantaneously.

[0028] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed therein. Any reference in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A pneumatic control circuit for a circuit board flipping machine, characterized in that: It includes several transistors, several diodes, several field-effect transistors, and several resistors. The base of the transistor Q1 among the several transistors is connected to the cathode of the diode D2 and one end of the resistor R2, the collector is connected to the anode of the diode D1 and one end of the resistor R1, and the emitter is connected to the drain of the field-effect transistor Q3; the base of the transistor Q2 is connected to the cathode of the diode D1 and one end of the resistor R3, the collector is connected to the anode of the diode D2 and one end of the resistor R4, and the emitter is connected to the drain of the field-effect transistor Q4; the gate of the field-effect transistor Q3 is connected to the gate of the field-effect transistor Q4; the source end of the field-effect transistor Q3 obtains a forward flip control signal; the source end of the field-effect transistor Q4 obtains a reverse flip control signal; the other end of the resistor R1, the other end of the resistor R2, the other end of the resistor R3, and the other end of the resistor R4 are grounded.

2. The pneumatic control circuit of the circuit board flipping machine according to claim 1, characterized in that: It also includes a trigger U2, an operational amplifier U3, and a capacitor C1. The first pin, the fourth pin, and one end of the resistor R8 of the trigger U2 are connected to the power supply, the second pin is connected to the sixth pin and one end of the resistor R10, the third pin is connected to the output end of the operational amplifier U3, the cathode of the diode D9, and one end of the resistor R9, and the fifth pin is connected to the anode of the diode D8; the in-phase terminal of the operational amplifier U3 is connected to one end of the capacitor C1, the cathode of the diode D3, the cathode of the diode D4, and one end of the resistor R6, and the inverting terminal is connected to one end of the resistor R7 and the other end of the resistor R8; the anode of the diode D3 is connected to the anode of the diode D2; the anode of the diode D4 is connected to the anode of the diode D1; the cathode of the diode D8 is connected to the gate of the field effect transistor Q3; the anode end of the diode D9 obtains the flip completion signal; the other end of the resistor R6, the other end of the resistor R7, the other end of the resistor R9, the other end of the resistor R10, and the other end of the capacitor C1 are grounded.

3. The pneumatic control circuit of the circuit board flipping machine according to claim 2, characterized in that: It also includes several operational amplifiers, capacitor C2, and resistor R5. Among the operational amplifiers, the operational amplifier U1 is connected to the cathode of the diode D5, the cathode of the diode D6, one end of the capacitor C2, and one end of the resistor R5 in the same phase, and the output is connected to the anode of the diode D7; the operational amplifier U4 is connected to the inverting end of the operational amplifier U5 in the same phase, and the output is connected to the anode of the diode D6; the inverting end of the operational amplifier U4 and the inverting end of the operational amplifier U5 obtain the gas source pressure signal; the output end of the operational amplifier U5 is connected to the anode of the diode D5; the cathode of the diode D7 is connected to the cathode of the diode D8; the other end of the capacitor C2 and the other end of the resistor R5 are grounded.

4. The pneumatic control circuit of the circuit board flipping machine according to claim 3, characterized in that: One end of the resistor R15 among the resistors is connected to the inverting end of the operational amplifier U4 and one end of the resistor R16, and the other end is connected to the non-inverting end of the operational amplifier U5 and one end of the resistor R14; the other end of the resistor R16 is connected to the power supply; and the other end of the resistor R14 is grounded.

5. The pneumatic control circuit of the circuit board flipping machine according to claim 3, characterized in that: One end of the resistor R12 among the plurality of resistors is connected to the power supply, and the other end is connected to the inverting terminal of the operational amplifier U1 and one end of the resistor R11; the other end of the resistor R11 is grounded.

6. The pneumatic control circuit of the circuit board flipping machine according to claim 1, characterized in that: The resistor R13 is further included. One end of the resistor R13 is connected to the gate of the field effect transistor Q3, and the other end is grounded.

7. The pneumatic control circuit of the circuit board flipping machine according to claim 2, characterized in that: The resistor R7 is an adjustable resistor.

8. The pneumatic control circuit of the circuit board flipping machine according to claim 4, characterized in that: The resistor R14 and the resistor R15 are adjustable resistors.

9. The pneumatic control circuit of the circuit board flipping machine according to claim 5, characterized in that: The resistor R11 is an adjustable resistor.

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