TWI566867B - Method for reducing the stray capacitance of a wire-cut electric discharge machine and a wire-cut electric discharge machine capable of reducing stray capacitance - Google Patents

Description

Method for reducing stray capacitance of wire-cut electric discharge machine and wire-cut electric discharge machine capable of reducing stray capacitance

The present invention relates to a method and a wire-cut electrical discharge machine using the same, and more particularly to a method for reducing the stray capacitance of a wire-cut electrical discharge machine and a wire-cut electrical discharge machine capable of reducing stray capacitance.

As shown in FIG. 1, the conventional wire-cut electrical discharge machine includes a processing platform 710, a high voltage discharge circuit 720, and a low voltage ignition circuit 730. The processing principle is that the low-voltage ignition circuit 730 first establishes a discharge arcing channel for a workpiece 740, and then the high-voltage discharge circuit 720 applies machining energy to the workpiece 740 through the discharge arcing channel for electrical discharge machining. Moreover, in order to obtain a better surface roughness on the machined surface of the workpiece 740, the discharge arcing channel energy generated by the low-voltage ignition circuit 730 is usually used for fine refinement. However, due to the stray capacitance of the wire-cut EDM machine, the energy of the low-voltage ignition circuit 730 is accumulated, and the energy release is performed while the discharge arc-trigger channel is established, so that the workpiece 740 is subjected to a higher expectation. More processing energy, not conducive to surface roughness.

Therefore, in order to obtain a better surface roughness, in addition to providing a switch SW for disconnecting the processing platform 710 in the high voltage discharge circuit 720, the energy of the low voltage ignition circuit 730 can be accumulated. The stray capacitance is reduced; at the same time, by adjusting the resistance of a variable resistor R of the low-voltage ignition circuit 730 and the voltage value of a low-voltage power source LPV, the current of the low-voltage ignition circuit 730 is decreased to reduce the discharge. The energy of the arcing channel. However, by reducing the energy of the discharge arcing channel, it is not only necessary to accurately adjust the low voltage ignition circuit 730, otherwise the discharge arcing channel will not be established, resulting in an increase in the cost of component design and control of the low voltage ignition circuit 730; Moreover, the increase in the resistance of the variable resistor R also reduces the power efficiency of the low voltage ignition circuit 730. Therefore, if the above shortcomings can be avoided, and the stray capacitance under this structure is reduced, not only can the wire-cut EDM have better surface roughness, but also a general low-voltage ignition circuit can be used to reduce the cost. And power efficiency is improved.

Accordingly, it is an object of the present invention to provide a method of reducing the stray capacitance of a wire-cut electrical discharge machine by using an isolation circuit.

Thus, the method of the present invention for reducing the stray capacitance of a wire-cut electric discharge machine is suitable for a wire-cut electric discharge machine. The wire-cut electric discharge machine comprises a processing platform and a low-voltage circuit module forming a low-voltage circuit with the processing platform. The method consists of the following steps:

Step A: Disconnect the electrical connection between the low voltage circuit module and the processing platform.

Step B: applying a pulse wave signal to the processing platform to obtain a response signal, and detecting an oscillation frequency of the processing platform by the response signal.

Step C: Design an electrical isolation device having an input winding and an output winding according to the oscillation frequency and the circuit characteristics of the low voltage circuit module.

Step D: electrically connecting the low voltage circuit module to the input winding to form a low voltage isolation circuit, and electrically connecting the processing platform to the output winding to form a processing isolation circuit; letting the discharge energy of the low voltage isolation circuit pass through the The coupling of the electrical isolation device is transmitted to the machining isolation circuit to cause the machining isolation circuit to resonate.

Another object of the present invention is to provide a wire electric discharge machine capable of reducing stray capacitance.

Thus, the wire-cut electrical discharge machine capable of reducing stray capacitance of the present invention is suitable for processing a workpiece and includes a processing platform, a high voltage circuit module, a low voltage circuit module, and an electrical isolation device.

The processing platform includes a table for the workpiece to be placed, and a pair of wire electrodes that should be placed on the table.

The high voltage circuit module is configured to form a high voltage circuit with the processing platform and provide a high voltage voltage to perform electrical discharge machining on the workpiece.

The low voltage circuit module includes a low voltage voltage source and a switch connected in series.

The electrical isolation device includes an input winding coupled to an output winding. Wherein, the processing platform is electrically connected to the output winding to form a processing isolation circuit. The low voltage circuit module is electrically connected to the input winding to form a low voltage isolation circuit, and a low voltage voltage is supplied from the low voltage voltage source to perform ignition discharge and trimming of the workpiece.

The effect of the invention is that the stray capacitance on the low voltage circuit module is isolated by the electrical isolation device, so that the machining energy applied to the workpiece by the machining isolation circuit can be more effectively controlled, and the workpiece has more Good surface roughness.

Referring to FIG. 2, an embodiment of a wire-cut electrical discharge machine capable of reducing stray capacitance is suitable for processing a workpiece 500, and includes a processing platform 100, a high voltage circuit module 200, and a low voltage circuit module 300. And an electrical isolation device 400.

The processing platform 100 includes a table 110 for the workpiece 500 to be placed, and a pair of wire electrodes 120 that are disposed on the table 110.

The high voltage circuit module 200 is configured to form a high voltage circuit with the processing platform 100 and provide a high voltage to discharge the workpiece 500.

The low voltage circuit module 300 includes a low voltage voltage source 310 and a switch 320 connected in series.

The electrical isolation device 400 includes an input winding 410 and an output winding 420 that are coupled. It should be noted that a general electrical isolation device refers to an isolation transformer having a core, which has a low operating frequency and is not suitable for use in a wire-cut electrical discharge machine. Therefore, in the embodiment, the electrical isolation device 400 can adopt an air core high-frequency transformer, an opto-isolated transformer, and a pulse-isolated transformer, and the working frequency can be between 1 MHz and 4 MHz, so as to be a low-voltage circuit module. 300 high frequency switching. Moreover, the electrical isolation device 400 is optimized according to the switching frequency of the switch 320 in the low voltage circuit module 300 and the circuit characteristics of the processing platform 100, and the related design method will be described later.

Thereby, the processing platform 100 is electrically connected to the output winding 420 to form a processing isolation circuit; the low voltage circuit module 300 is electrically connected to the input winding 410 to form a low voltage isolation circuit, and the low voltage voltage source 310 provides a The low voltage voltage is used to perform ignition discharge and trimming of the workpiece 500. In this way, in the repair mode, the low voltage voltage is switched through the switch 320, so that the low voltage isolation circuit generates a circuit oscillation, and the circuit winding is transmitted by the input winding 410 to induce the output winding 420. Therefore, the stray capacitance on the low voltage isolation circuit can be isolated, so that the stray capacitance affecting the workpiece 500 can be effectively reduced. At the same time, the machining energy applied to the workpiece 500 by the machining isolating circuit is more effectively controlled, giving the workpiece 500 a better surface roughness.

In view of the above description, it can be appreciated that a major contribution of the present invention is to reduce the stray capacitance of the workpiece 500 during trimming through the electrical isolation device 400. However, the design of the electrical isolation device 400 must also optimize the energy conversion efficiency between the input winding 410 and the output winding 420 in response to the electrical loop characteristics of each wire-cut electrical discharge machine.

Therefore, the method of the present invention for reducing the stray capacitance of a wire-cut electric discharge machine is suitable for a one-wire electric discharge machine as shown in FIG. The wire electric discharge machine includes a processing platform 100 and a low voltage circuit module 300 that forms a low voltage circuit with the processing platform 100. The method includes the process steps as shown in FIG.

Step S31: Disconnect the electrical connection between the low voltage circuit module 300 and the processing platform 100.

Step S32: Applying a pulse wave signal to the processing platform 100 to obtain a response signal, and detecting an oscillation frequency of the processing platform 100 from the response signal.

It should be noted that the processing platform 100 necessarily has a driving component such as a servo motor, and an impedance is generated between the workpiece 500 and the processing platform 100, and a stray capacitance of the processing platform 100 is determined by the above. Drive element and impedance. Therefore, the oscillation frequency is related to the stray capacitance of the processing platform 100.

Step S33: Design an electrical isolation device 400 having an input winding 410 and an output winding 420 according to the oscillation frequency and the circuit characteristics of the low voltage circuit module 300.

Step S34: The low voltage circuit module 300 is electrically connected to the input winding 410 to form a low voltage isolation circuit, and the processing platform 100 is electrically connected to the output winding 420 to form a processing isolation circuit; The discharge energy is transmitted to the processing isolation circuit through the coupling of the electrical isolation device 400, causing the processing isolation circuit to resonate.

It should be noted that, in order to switch the high frequency of the low voltage circuit module 300, the electrical isolation device 400 must use a high frequency transformer such as an air core, an opto-isolated transformer, and a pulse-isolated transformer to operate at a frequency of 1 MHz. Device between 4MHz. Moreover, the turns ratio between the output and the input windings 420, 410 and the wound wire must match the circuit characteristics of the processing platform 100 and the low voltage circuit module 300, and the low voltage isolation circuit and the processing isolation circuit are allowed. Resonance can occur between a particular resonant frequency. In this way, the response waveform on the processing isolation loop can generate the maximum amplitude, so that the processing isolation loop can maximize the energy converted from the low voltage isolation loop to achieve the best conversion efficiency.

In summary, the present invention isolates the stray capacitance on the low voltage circuit module 300 by the electrical isolation device 400, so that the processing energy applied to the workpiece 500 by the processing isolation circuit can be more effectively controlled, and The workpiece 500 has a better surface roughness. Not only is the disadvantage of the conventional architecture effectively improved, but also the cost is reduced. At the same time, the efficiency of the overall electrical energy is improved by the design of the electrical isolation device 400, so that the object of the present invention can be achieved.

However, the above is only the embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, all the equivalent equivalent changes and modifications according to the scope of the patent application and the patent specification of the present invention are still It is within the scope of the patent of the present invention.

100‧‧‧Processing platform
110‧‧‧Workbench
120‧‧‧ wire electrode
200‧‧‧High voltage circuit module
300‧‧‧Low-voltage circuit module
310‧‧‧Low voltage source
320‧‧‧ switch
400‧‧‧Electrical isolation device
410‧‧‧Input winding
420‧‧‧Output winding
500‧‧‧Workpiece
710‧‧‧Processing platform
720‧‧‧High voltage discharge circuit
730‧‧‧Low-voltage ignition circuit
740‧‧‧Workpiece
LPV‧‧‧Low-voltage power supply
R‧‧‧Variable resistor
SW‧‧ switch
S31~S34‧‧‧Steps

Other features and effects of the present invention will be apparent from the following description of the drawings, wherein: Figure 1 is a circuit diagram illustrating the structure of a conventional wire-cut electrical discharge machine and its electrical discharge machining of a workpiece 2 is a circuit diagram illustrating an embodiment of a wire-cut electrical discharge machine capable of reducing stray capacitance and suitable for processing a workpiece; and FIG. 3 is a flow chart illustrating the reduction of wire-cut discharge of the present invention Method steps for the stray capacitance of the processing machine.

100‧‧‧Processing platform

110‧‧‧Workbench

120‧‧‧ wire electrode

200‧‧‧High voltage circuit module

300‧‧‧Low-voltage circuit module

310‧‧‧Low voltage source

320‧‧‧ switch

400‧‧‧Electrical isolation device

410‧‧‧Input winding

420‧‧‧Output winding

500‧‧‧Workpiece

Claims (3)

A method for reducing stray capacitance of a wire-cut electric discharge machine is suitable for a wire-cut electric discharge machine; the wire-cut electric discharge machine comprises a processing platform, and a low-voltage circuit module forming a low-voltage circuit with the processing platform; The method comprises the following steps: Step A: disconnecting the electrical connection between the low voltage circuit module and the processing platform; step B: applying a pulse wave signal to the processing platform to obtain a response signal, and the response signal is obtained Detecting an oscillation frequency of the processing platform; Step C: designing an electrical isolation device having an input winding and an output winding according to the oscillation frequency and circuit characteristics of the low voltage circuit module, the electrical isolation device adopting an air core One of a high frequency transformer, an opto-isolated transformer, and a pulse isolated transformer; and step D: electrically connecting the low voltage circuit module to the input winding to form a low voltage isolation circuit, and electrically connecting the processing platform Output windings to form a process isolation loop; let the discharge energy of the low voltage isolation loop pass through the coupling of the electrical isolation device And passed to the machining isolation circuit to cause the machining isolation circuit to resonate. A method of reducing the stray capacitance of a wire-cut electrical discharge machine according to claim 1, wherein in the step B, the oscillation frequency is a stray capacitance associated with the processing platform. A wire-cut electric discharge machine capable of reducing stray capacitance, suitable for processing a workpiece; the wire-cut electric discharge machine comprises: A processing platform includes a workbench for placing the workpiece, and a pair of wire electrodes disposed on the workbench; a high voltage circuit module for forming a high voltage circuit with the processing platform, and providing a high voltage voltage to The workpiece is subjected to electrical discharge machining; a low voltage circuit module comprising a low voltage voltage source and a switch connected in series; and an electrical isolation device, wherein the air core is a high frequency transformer, an optically isolated transformer, and a pulse isolated transformer. And comprising: an input winding coupled to the output winding; wherein the processing platform is electrically connected to the output winding to form a processing isolation circuit, the low voltage circuit module electrically connecting the input winding to form a low voltage isolation a loop, and a low voltage voltage is supplied from the low voltage voltage source to perform an ignition discharge and a trimming process on the workpiece.