CN214626826U

CN214626826U - Pulse power supply control system of diamond grinding wheel dresser

Info

Publication number: CN214626826U
Application number: CN202120412420.6U
Authority: CN
Inventors: 顾林峰; 季希宁; 鱼志强; 颜杰; 成哲; 朱叶青; 刘斌
Original assignee: Suzhou Electromachining Machine Tool Research Institute Co ltd
Current assignee: Suzhou Electromachining Machine Tool Research Institute Co ltd
Priority date: 2021-02-25
Filing date: 2021-02-25
Publication date: 2021-11-05
Anticipated expiration: 2031-02-25

Abstract

A kind of diamond grinding wheel dresser pulse power control system, including: the human-computer interface is used for setting processing parameters by a user; the programmable program controller is used for system main control and is connected with a human-computer interface; the motion control system is used for controlling servo feeding and workpiece spindle rotation and is connected with the programmable controller; the pulse power supply is used for controlling the pulse width, the pause and the current magnitude of the pulse power supply and is connected with the programmable program controller; a gap detection circuit and a power MOS tube; the gap detection circuit controls the motion control system to control the discharge gap between a machined workpiece and an electrode and the workpiece rotation speed to form closed-loop feedback, and meanwhile, a pulse power supply is controlled by a gap detection signal to carry out self-adaptive discharge pulse fine adjustment.

Description

Pulse power supply control system of diamond grinding wheel dresser

Technical Field

The utility model relates to an electric spark discharge machining pulse power control design technical field, in particular to diamond wheel dresser pulse power control system.

Background

Electrical Discharge Machining (EDM) is widely used because it can machine difficult-to-cut materials and parts having complicated shapes. The main part is a pulse power supply, and the technical performance of the pulse power supply directly influences various technological indexes of electric spark forming machining, such as machining quality precision, machining speed, electrode loss and the like;

at present, the electric spark machining pulse power supply can be classified into a relaxation type, an electronic tube type, a gate flow type, a pulse generator type, a thyristor type and a transistor type according to the types of main elements in a main loop, wherein the transistor type pulse power supply becomes an industrial pulse power supply main current type. However, with the development of the electric spark machining technology, in order to further improve the effective pulse utilization rate, achieve high speed, low consumption, stable machining and some special requirements, on the basis of a thyristor type or transistor type pulse power supply, a plurality of novel power supplies and circuits are derived, and the system power and the discharge machining precision are improved;

the man-machine interaction control is used as an intelligent industrial technology, the user experience of the product intelligent system can be well improved, and the user can realize real-time control over the processing system through on-screen operation. However, in the industry, the application of human-computer interaction control on products of a diamond grinding wheel dresser control system is less;

at present, the diamond grinding wheel dresser needs to be capable of adapting to severe machining environments of steel plants due to complex working environments and needs to run for a long time, so that the requirement on the working stability of a machine tool is high, and the control mode of the diamond grinding wheel dresser often adopts a gear knob switch to trigger a relay to act so as to control a pulse power supply board to realize discharge machining. The pulse power supply of the trimming machine is usually realized by adopting a pulse oscillation chip and a push-pull circuit. The control system can meet the basic rough machining precision requirement of an iron and steel plant, but the fine machining precision is limited due to the weak anti-interference capability and poor stability of the pulse power supply control circuit.

In view of this, how to design a pulse power control system capable of improving the anti-interference capability, stability and precision of the pulse power control circuit to overcome the above disadvantages is the subject of the present invention.

Disclosure of Invention

The utility model provides a diamond wheel finisher pulse power control system, its purpose is to solve current pulse power control circuit interference killing feature weak, and poor stability has restricted the problem of finish machining precision.

In order to achieve the above purpose, the utility model adopts the technical scheme that: a pulse power supply control system of a diamond grinding wheel dresser comprises a human-computer interface, a pulse power supply control module and a pulse power supply control module, wherein the human-computer interface is used for setting processing parameters by a user; the programmable program controller is used for system main control and is connected with a human-computer interface; the motion control system is used for controlling servo feeding and workpiece spindle rotation and is connected with the programmable controller; the pulse power supply is used for controlling the pulse width, the pause and the current magnitude of the pulse power supply and is connected with the programmable program controller; a gap detection circuit and a power MOS tube;

the gap detection circuit controls the motion control system to control the discharge gap between the machined workpiece and the electrode and the workpiece rotation speed to form closed-loop feedback, and meanwhile, the gap detection signal controls the pulse power supply to perform self-adaptive discharge pulse fine adjustment; the pulse power supply adopts a multi-loop high-low voltage composite pulse power supply, the pulse power supply comprises a communication module, a single chip microcontroller (MCU control system), a complex programmable logic device (CPLD control system), a power amplification circuit and a power supply, the human-computer interface is connected with the single chip microcontroller through a programmable controller and the communication module, and the single chip microcontroller is connected with the complex programmable logic device, the power amplification circuit and a gap detection circuit;

the power amplification circuit drives the power MOS tube to work through the driving circuit, and the electric discharge machining between the electrode and the workpiece is realized.

The relevant content in the above technical solution is explained as follows:

1. in the above scheme, the motion control system includes servo control and workpiece rotation, the servo control includes a servo driver and a servo motor, the servo driver and the servo motor drive the workpiece to rotate in the B-axis direction, and the servo driver and the servo motor drive the electrodes to rotate in the X-axis direction and the R-axis direction.

2. Above-mentioned scheme, including chip U14 in the power amplification circuit, there are 1 to 8 interfaces on the chip, interface 2 connects power input VC5, interface 4 connects resistance R33, another termination input signal end TR5 of resistance R33,

interface

1 and 4 are unsettled, the anodal VD of interface 8 connection power, interface 6 connects G6, G6 gives the power MOS pipe for output signal, interface 5 ground connection GND2, interface 7 is unsettled.

3. IN the scheme, the gap detection circuit module comprises a gap detection circuit, wherein the gap detection circuit comprises an anode E, a cathode W, a rectifier diode IN4007, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a voltage regulator Z3, a capacitor C11, a chip HCNR200 and amplifier triodes Q1 and Q2, wherein the E and the W are respectively connected with the electrode and a workpiece and can be exchanged IN sequence, an input voltage is firstly rectified through the rectifier diode IN4007, then forms resistor voltage division through the resistor R3 and the resistor R4, and samples voltage at two ends of the resistor R4; the voltage at two ends of the R4 passes through a voltage stabilizing circuit formed by R5 and Z3 and an RC filter circuit formed by R6 and C11, and then the voltage control is converted into current control through R7; the chip is provided with 1 to 8 pins,

pins

3 and 4 of the HCNR200 chip are linear feedback compensation control ends,

pins

1 and 2 are LED light output, and the voltage of a photodiode PD1 (pins 3 and 4) can be always controlled to be 0 through a pair of complementary control amplification triodes Q1 and Q2, namely the current of a collector of a triode Q1 is controlled to control the current of a collector of the triode Q2 when the triode Q2 is conducted according to the input of an end R7, so that the conducting current of the LED (pins 1 and 2) is controlled, and the light output of the LED is stable and linear; PD2 (pins 5 and 6) is analog output, the output of the photodiode PD2 is determined by the light output of the LED, and the light output is mainly subjected to voltage stabilization through R10 and D2 and then subjected to voltage division output through R14 and R15; and the linear feedback compensation control consisting of Q3, R11, R12, Q4 and R13 makes the PD2 output stable and linear according to the light output of the LED through a pair of triodes complementarily controlled by Q3 and Q4.

4. In the above scheme, the power amplification circuit includes a workpiece processing high-voltage and low-voltage processing control selection circuit, the workpiece processing high-voltage and low-voltage processing control selection circuit includes a three-way fuse FU3, and further includes input voltages U31, V31, W31, a switch KM1, a switch KM4, a switch KM5, a transformer TM, winding coils U3, V3, and W3, the three-way voltages U31, V31, and W31 are input and controlled by a switch KM1, the three-way voltages U31, V31, and W31 are respectively connected to U3, V3, and W3 winding coils, the three winding coils are divided into two ways by the transformer TM, and controlled by KM4 and KM5 switches, and divided into three cases, namely, a first case: KM4 ON, KM5 OFF; and the second method comprises the following steps: KM4 off, KM5 on; the third KM4 and KM5 were both on, and selected according to the rough and fine machining, and the output terminals of KM4 and KM5 were both connected to power MOS transistors.

5. In the scheme, the gap detection circuit is an analog quantity voltage detection circuit, the detection range is DC 0V-10V, and the measurement precision reaches 0.01V.

6. In the above scheme, the power amplification circuit is composed of a high-precision low-delay optical coupler and an auxiliary circuit thereof, and the main chip type is TLP 250.

7. In the above scheme, the human-computer interface is a touch screen system module capable of being programmed and stored online.

8. In the scheme, the programmable program controller and the pulse power supply adopt an RS485 two-way communication transmission mode, and the communication protocol is a Modbus-RTU standard mode.

The utility model discloses a design principle and effect: the electric spark discharge pulse power supply processing of the diamond grinding wheel trimming machine is controlled by man-machine interaction, a user can control the pulse width, pulse outage and processing current magnitude of power supply pulse in real time, a multi-loop high-low voltage composite pulse power supply is adopted, the rough processing efficiency and the finish processing quality precision are improved, a single-chip microcontroller is combined with a complex programmable logic device, the power supply control pulse trigger form is improved, compared with a pulse trigger with an oscillation chip structure, the precision is higher, the anti-interference capability is strong, the driving capability of a power MOS (metal oxide semiconductor) tube is improved by utilizing a high-frequency driving chip, compared with a push-pull circuit, the rising edge delay time of the pulse is reduced, and the pulse waveform distortion is prevented, and the output of the driving chip is stable, the stability of the discharge machining of the pulse power supply is improved, and the problems that the existing pulse power supply control circuit is weak in anti-interference capability and poor in stability and limits the precision of finish machining are solved.

Drawings

FIG. 1 is a general block diagram of a pulse power supply control system according to an embodiment of the present invention;

FIG. 2 is a block diagram of a pulse control system according to an embodiment of the present invention;

fig. 3 is a flow chart of the pulse power control system according to the embodiment of the present invention.

Fig. 4 is a circuit diagram of a power amplifier circuit according to an embodiment of the present invention.

Fig. 5 is a circuit diagram of the gap detection circuit according to the embodiment of the present invention.

Fig. 6 is a working principle diagram of the electrode for processing the workpiece according to the embodiment of the present invention.

Fig. 7 is a circuit diagram for controlling and selecting high-low voltage processing in workpiece processing according to the embodiment of the present invention.

Detailed Description

The invention will be further described with reference to the following drawings and examples:

example (b): pulse power supply control system of diamond grinding wheel dresser

As shown in fig. 1-2, a pulse power control system for a diamond wheel dresser includes a human-machine interface for a user to set processing parameters; the programmable program controller is used for system main control and is connected with a human-computer interface; the motion control system is used for controlling servo feeding and workpiece spindle rotation and is connected with the programmable controller; the pulse power supply is used for controlling the pulse width, the pause and the current magnitude of the pulse power supply and is connected with the programmable program controller; a gap detection circuit and a power MOS tube.

The gap detection circuit controls the motion control system to control the discharge gap between the machined workpiece and the electrode and the workpiece rotation speed to form closed-loop feedback, and meanwhile, the gap detection signal controls the pulse power supply to perform self-adaptive discharge pulse fine adjustment. The pulse power supply adopts a multi-loop high-low voltage composite pulse power supply, the pulse power supply comprises a communication module, a single chip microcontroller (MCU control system), a complex programmable logic device (CPLD control system), a power amplification circuit and a power supply, the human-computer interface is connected with the single chip microcontroller through a programmable controller and the communication module, and the single chip microcontroller is connected with the complex programmable logic device, the power amplification circuit and a gap detection circuit.

The circuit diagram shown in fig. 4 corresponds to the power amplifier circuit shown in fig. 2, the power amplifier circuit is composed of a high-precision low-delay optical coupler and an auxiliary circuit thereof, in the diagram, U14 is a main chip, the model of the main chip is TLP250, 1 to 8 interfaces are arranged on the chip, the interface 2 is connected with a power input end VC5, the interface 4 is connected with a resistor R33, the other end of the resistor R33 is connected with an input signal end TR5, the

interfaces

1 and 4 are suspended, the interface 8 is connected with a power positive electrode VD, the interface 6 is connected with G6, the G6 outputs signals to a power MOS transistor, the interface 5 is grounded GND2, the interface 7 is suspended, and the power amplifier circuit drives the power MOS transistor to operate through a driving circuit, so as to realize discharge machining between the electrode and the workpiece.

On the basis, the circuit diagram shown in fig. 6 corresponds to the motion control system module shown in fig. 2, as shown in fig. 6, the workpiece is a diamond grinding wheel, the electrode is a graphite wheel, the motion control system comprises a servo driver and a servo motor, the servo driver and the servo motor drive the diamond grinding wheel to rotate in the B-axis direction, the servo driver and the servo motor drive the graphite wheel to rotate in the X-axis direction and the R-axis direction, during machining, the graphite wheel is used as a tool electrode cathode, the diamond grinding wheel is used as a workpiece anode to be machined, kerosene is used as a working fluid, and the diamond grinding wheel is subjected to forming machining through pulse spark discharge between two stages.

On the basis, the circuit diagram IN fig. 5 corresponds to the gap detection circuit module IN fig. 2, the gap detection circuit is an analog quantity voltage detection circuit, the detection range is DC 0V-10V, the measurement precision reaches 0.01V, the E is the positive electrode, the W is the negative electrode, the E and the W are respectively connected with the electrode and the workpiece, and the sequence can be exchanged, the input voltage is firstly rectified by an IN4007 rectifier diode, then forms resistance voltage division by R3 and R4, and samples the voltage at two ends of a resistor R4; the voltage at two ends of the R4 passes through a voltage stabilizing circuit formed by R5 and Z3 and an RC filter circuit formed by R6 and C11, and then the voltage control is converted into current control through R7;

pins

3 and 4 of the HCNR200 chip are linear feedback compensation control terminals,

pins

1 and 2 are LED light outputs, and through a pair of complementary control amplification triodes Q1 and Q2, it can always try to control the voltage of the photodiode PD1 (pins 3 and 4) to be 0 according to the input of the terminal R7, that is, control the current magnitude of the collector of the triode Q1 to control the collector current magnitude when the triode Q2 is turned on, thereby controlling the turn-on current magnitude of the LEDs (pins 1 and 2) and stabilizing and linearizing the light output of the LEDs; PD2 (pins 5 and 6) is analog output, the output of the photodiode PD2 is determined by the light output of the LED, and the light output is mainly subjected to voltage stabilization through R10 and D2 and then subjected to voltage division output through R14 and R15; and the linear feedback compensation control consisting of Q3, R11, R12, Q4 and R13 makes the PD2 output stable and linear according to the light output of the LED through a pair of triodes complementarily controlled by Q3 and Q4.

On the basis, fig. 7 corresponds to the high-low voltage processing control module in fig. 2 and the rough and fine processing setting module in fig. 3, FU3 in fig. 7 is a three-way fuse, and further includes three voltage inputs of U31, V31 and W31, and is controlled by KM1, the three voltages of U31, V31 and W31 are respectively connected to winding coils of U3, V3 and W3, the three winding coils are divided into two through a transformer TM, and are controlled by KM4 and KM5 switches, which are divided into three cases, namely, the first case: KM4 ON, KM5 OFF; and the second method comprises the following steps: KM4 off, KM5 on; the third KM4 and KM5 were both on, and selected according to the rough and fine machining, and the output terminals of KM4 and KM5 were both connected to power MOS transistors.

On the basis, the human-computer interface is a touch screen system module which can be programmed and stored on line; the touch screen is convenient for workers to observe and operate, and the working efficiency is improved.

On the basis, the programmable program controller and the pulse power supply adopt an RS485 two-way communication transmission mode, and the communication protocol is a Modbus-RTU standard mode; through Modbus communication for instruction transmission control is succinct, only needs two data lines can realize the real-time interaction of data, saves outside hardware resources, and the RTU communication protocol of Modbus itself needs to carry out real-time check to data interaction simultaneously, avoids erroneous command's production, has improved the interference killing feature greatly.

On the basis, the communication module adopts 485 communication transmission.

As shown in fig. 3, the human-machine interface, the programmable controller and the one-chip microcontroller are initialized, and the system is in a power-on and non-discharge state. After initialization is completed, a user selects high-voltage rough machining or low-voltage finish machining and sets machining parameters through a human-computer interface. After parameter setting is completed, the programmable controller carries out system setting and functional instruction code generation and carries out data interaction with the single chip microcontroller through the 485 communication module, the single chip microcontroller decodes functional instructions and runs an instruction corresponding program to generate corresponding control signals, the complex programmable logic controller receives control signals sent by the single chip microcontroller to carry out corresponding function setting and generate control pulses, and the pulses pass through the power operational amplifier circuit to improve driving capability and control on and off of the power MOS tube to generate power pulses. The positive and negative poles of the power supply pulse are respectively connected with the electrode and the workpiece to carry out process machining, meanwhile, the gap detection circuit detects machining voltage, generates analog quantity and sends the analog quantity to the programmable controller to form closed-loop control, and the adjustment of the gap between the workpiece and the electrode and the control of the machining rotation speed of the workpiece are carried out according to the analog quantity. Meanwhile, the analog quantity signal is also used as a reference signal for the self-adaptive adjustment of the pulse power supply pulse, and the pulse width and the pulse pause duty ratio are finely adjusted in the same pulse period.

The programmable program controller and the pulse power supply are controlled by adopting a Modbus communication protocol, data transmission is carried out through a 485 communication module, instruction decoding and corresponding function setting are carried out through an MCU control system after function codes are transmitted through 485 communication, corresponding driving pulses are generated through a CPLD control system, and the power MOS tube is driven to work through a power amplification circuit, so that the electric discharge machining between the electrode and the workpiece is realized. The gap detection circuit controls the motion control system, controls the discharge gap between the machined workpiece and the electrode and the workpiece rotation speed to form closed-loop feedback, and simultaneously controls the pulse power supply to perform self-adaptive discharge pulse fine adjustment by a gap detection signal; the electric spark discharge pulse power supply processing of the diamond grinding wheel trimming machine is controlled by man-machine interaction, a user can control the pulse width, pulse outage and processing current magnitude of power supply pulse in real time, a multi-loop high-low voltage composite pulse power supply is adopted, the rough processing efficiency and the finish processing quality precision are improved, a single-chip microcontroller is combined with a complex programmable logic device, the power supply control pulse trigger form is improved, compared with a pulse trigger with an oscillation chip structure, the precision is higher, the anti-interference capability is strong, the driving capability of a power MOS (metal oxide semiconductor) tube is improved by utilizing a high-frequency driving chip, compared with a push-pull circuit, the rising edge delay time of the pulse is reduced, and the pulse waveform distortion is prevented, and the output of the driving chip is stable, the stability of the discharge machining of the pulse power supply is improved, and the problems that the existing pulse power supply control circuit is weak in anti-interference capability and poor in stability and limits the precision of finish machining are solved.

The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose of the embodiments is to enable people skilled in the art to understand the contents of the present invention and to implement the present invention, which cannot limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered by the protection scope of the present invention.

Claims

1. The utility model provides a diamond wheel finisher pulse power control system which characterized in that:

the system comprises a human-computer interface, a processing module and a processing module, wherein the human-computer interface is used for setting processing parameters by a user; the programmable program controller is used for system main control and is connected with a human-computer interface; the motion control system is used for controlling servo feeding and workpiece spindle rotation and is connected with the programmable controller; the pulse power supply is used for controlling the pulse width, the pause and the current magnitude of the pulse power supply and is connected with the programmable program controller; a gap detection circuit and a power MOS tube;

the gap detection circuit controls the motion control system to control the discharge gap between the machined workpiece and the electrode and the workpiece rotation speed to form closed-loop feedback, and meanwhile, the gap detection signal controls the pulse power supply to perform self-adaptive discharge pulse fine adjustment;

the pulse power supply adopts a multi-loop high-low voltage composite pulse power supply, the pulse power supply comprises a communication module, a single-chip microcontroller, a complex programmable logic device, a power amplification circuit and a power supply, the human-computer interface is connected with the single-chip microcontroller through the programmable controller and the communication module, and the single-chip microcontroller is connected with the complex programmable logic device, the power amplification circuit and the gap detection circuit;

2. The diamond wheel dresser pulse power supply control system of claim 1, wherein: the motion control system comprises servo control and workpiece rotation, the servo control comprises a servo driver and a servo motor, the servo driver and the servo motor drive the workpiece to rotate in the B-axis direction, and the servo driver and the servo motor drive electrodes to rotate in the X-axis direction and the R-axis direction.

3. The diamond wheel dresser pulse power supply control system of claim 1, wherein: including chip U14 in the power amplifier circuit, there are 1 to 8 interfaces on the chip, interface 2 connects power input VC5, interface 4 connects resistance R33, another termination input signal end TR5 of resistance R33, interface 1 and 4 are unsettled, the anodal VD of interface 8 power connection, interface 6 connects G6, power MOS pipe is given for output signal to G6, interface 5 ground connection GND2, interface 7 is unsettled.

4. The diamond wheel dresser pulse power supply control system of claim 1, wherein: the power amplification circuit comprises a workpiece processing high-voltage and low-voltage processing control selection circuit, the workpiece processing high-voltage and low-voltage processing control selection circuit comprises a three-way fuse FU3, and further comprises input voltages U31, V31, W31, a switch KM1, a switch KM4, a switch KM5, a transformer TM, winding coils U3, V3 and W3, the three voltages U31, V31 and W31 are input and controlled by a switch KM1, the three voltages U31, V31 and W31 are respectively connected with the winding coils U3, V3 and W3, the three winding coils are divided into two paths through the transformer TM, and are controlled by KM4 and KM5 switches, and the three conditions are divided into three conditions, namely: KM4 ON, KM5 OFF; and the second method comprises the following steps: KM4 off, KM5 on; the third KM4 and KM5 were both on, and selected according to the rough and fine machining, and the output terminals of KM4 and KM5 were both connected to power MOS transistors.

5. The diamond wheel dresser pulse power supply control system of claim 1, wherein: the gap detection circuit is an analog quantity voltage detection circuit, the detection range is DC 0V-10V, and the measurement precision reaches 0.01V.

6. The diamond wheel dresser pulse power supply control system of claim 1, wherein: the power amplifying circuit is composed of a high-precision low-delay optical coupler and an auxiliary circuit thereof, and the model of the main chip is TLP 250.

7. The diamond wheel dresser pulse power supply control system of claim 1, wherein: the human-computer interface is a touch screen system module which can be programmed and stored on line.

8. The diamond wheel dresser pulse power supply control system of claim 2, wherein: the programmable program controller and the pulse power supply adopt an RS485 two-way communication transmission mode, and the communication protocol is a Modbus-RTU mode.