JP2002263957A - Machining power supply device for electric discharge machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machining power supply device for an electric discharge machine for suppressing the generation of an oscillating current and achieving stable machinability. SOLUTION: The machining power supply device for the electric discharge machine for machining a workpiece 2 by supplying machining power into an interpole between an electrode 1 and the workpiece 2 comprises a power supply 3 for generating pulse voltage, a feeder 4 constituted by a distribution constant line for supplying the output of the power supply 3 to the interpole, a series structure of a resistance 7 and switching means 8 connected in parallel to the electrode 1 and the workpiece 2 to the load side of the feeder 4 and having a characteristic impedance similar to that of the feeder 4, and control means 9 for controlling the switching means 8 to be turned on or off. The generation of the oscillating current is suppressed and the stable machinability is achieved. Even if the feeder has a different length due to a difference in type and size of the electric discharge machine, the machinability is kept unchanged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of processing a workpiece by supplying a processing power between an electrode and a workpiece.
The present invention relates to an improvement in a machining power supply device of an electric discharge machine.

[0002]

2. Description of the Related Art FIG. 13 is a configuration diagram showing a machining power supply device of a conventional electric discharge machine, wherein 1 is an electrode,
2 is a workpiece, 3 is a power supply for generating a pulse voltage, 3a and 3b are output terminals of the power supply 3, and 4 is an output terminal of the power supply 3.
A feed line using a coaxial cable, which is a distributed constant line for supplying between the poles of the feed line and the workpiece 2, 4a and 4b are ends of the feed line 4, 5 and 6 are electric wires, and L is a load.

[0003] One end of a power supply line 4 is connected to an output terminal 3a of a power supply 3.
And 3b, and the other end 4a of the feed line 4 is connected to an electric wire 5
And the other end 4 b of the power supply line 4 is connected to the workpiece 2 via the electric wire 6. The wires 5 and 6 have some inductance.

FIG. 14 is a waveform diagram showing an example of a machining current between the poles by a machining power supply device of a conventional electric discharge machine.
The case where the pulse width T of the output voltage from the power supply 3 is 1.41 μs and the propagation time Td of the power supply line 4 is 38 ns is shown.
Looking at the machining current waveform in FIG. 14, it can be seen that an oscillating current flows at the rise and fall. Such an oscillating current is generated by repeated reflection of power because the characteristic impedance of the power supply line 4 does not match the impedance of the load L. If the magnitude of the oscillating current is smaller than the peak value of the machining current,
There is no problem in processing performance.

[0005]

FIG. 15 is a waveform diagram showing an example of the machining current between the poles by the machining power supply device of the conventional electric discharge machine. The pulse width T of the output voltage from the power supply 3 is shown in FIG.
Is as short as 0.25 μs. Also,
The length of the feed line 4 can be represented by the power propagation time Td. FIG. 15A shows the case where Td is 38 ns.
5B shows the case where Td is 63 ns, and FIG. 15C shows the case where Td is 83 ns. In each case, the magnitude of the oscillating current is smaller than the peak value of the machining current. Size that cannot be ignored.

As described above, in the machining power supply device of the conventional electric discharge machine, a relatively large oscillating current is generated in the machining current waveform particularly when the pulse width is short, and stable machining performance cannot be obtained. There was a problem. For example, when the pulse width T of the output voltage from the power supply 3 approaches the propagation time Td of the power supply line 4 in order to perform high-precision processing or the like (for example, as shown in FIG. When T is changed from 1.4 μs to 0.25 μs), that is, when the pulse width is short and the peak current is small, a relatively large oscillating current is generated between the poles and a desired machining current does not flow. Processing performance decreases.

When the propagation time Td of the feeder line 4 changes as shown in FIGS. 15A to 15C, that is, the machining current waveform changes depending on the length of the feeder line 4. When the length of the feeder line 4 is different depending on the model or size, there is a problem that the same processing performance cannot be obtained.

The present invention has been made to solve the above problems, and can suppress the generation of an oscillating current.
An object of the present invention is to provide a machining power supply device for an electric discharge machine capable of obtaining stable machining performance.

It is another object of the present invention to provide a machining power supply apparatus for an electric discharge machine which can obtain the same machining performance even when the length of a power supply line is different due to a difference in the type or size of the electric discharge machine. .

[0010]

According to the present invention, there is provided a machining power supply apparatus for an electric discharge machine, which supplies machining power between an electrode and a workpiece so as to machine the workpiece. In the processing power supply device of the machine, a power supply that generates a pulse voltage, a power supply line configured by a distributed constant line for supplying the output of the power supply between the gaps, the electrode on the load side of the power supply line, It is provided with a series body of a resistance and a switching means equivalent to the characteristic impedance of the power supply line and connected in parallel with the workpiece, and a control means for controlling on / off of the switching means.

Further, the machining power supply device for an electric discharge machine according to the present invention supplies machining electric power between a pole between an electrode and a workpiece to thereby provide a machining power for the electric discharge machine for machining the workpiece. In the supply device, a power supply that generates a pulse voltage, a power supply line configured by a distributed constant line for supplying the output of the power supply between the gaps, and the electrode and the workpiece on the load side of the power supply line. It is provided with a series connection of a resistor, a capacitor, and a switching means equivalent to the characteristic impedance of the power supply line connected in parallel, and a control means for controlling on / off of the switching means.

Further, in the machining power supply apparatus for an electric discharge machine according to the present invention, the capacitance of the capacitor is adjusted so that the time constant of a series circuit constituted by the resistor is longer than the propagation time of the power supply line. It is set to.

In the machining power supply device for an electric discharge machine according to the present invention, when the output pulse width of the power supply is about 1 μs or less, the control means turns on the switching means.

Further, the machining power supply apparatus for an electric discharge machine according to the present invention supplies machining electric power between a pole between an electrode and a workpiece so that the machining power of the electric discharge machine for machining the workpiece is provided. In the supply device, a power supply that generates a pulse voltage, a power supply line configured by a distributed constant line for supplying the output of the power supply between the gaps, and a power supply line connected in series to a power supply side of the power supply line, It comprises a parallel body of a resistor, an inductor, and a switching means equivalent to the characteristic impedance of the feeder line, and control means for controlling on / off of the switching means.

Further, in the machining power supply device for an electric discharge machine according to the present invention, when the output pulse width of the power supply is approximately 1 μs or less, the control means turns off the switching means.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a configuration diagram showing a machining power supply device of an electric discharge machine according to Embodiment 1 of the present invention. In the drawing, reference numeral 1 denotes an electrode, 2 denotes a workpiece, 3 denotes a power supply for generating a pulse voltage, Reference numerals 3a and 3b denote output terminals of the power supply 3, 4 denotes a feed line using a coaxial cable which is a distributed constant line for supplying the output of the power supply 3 between the electrode 1 and the workpiece 2, and 4a and 4b denote feed lines. Ends 5 and 6 of the power supply line 4 are electric wires, 7 is a resistor, 8 is a switching means, 9 is a control means for controlling ON / OFF of the switching means 8, and L is a load. The resistor 7 has a resistance value equal to the characteristic impedance of the feed line 4, and a series body of the resistor 7 and the switching means 8 is connected to the load side of the feed line 4 in parallel with the load L.

FIG. 2 is a waveform diagram showing an example of a machining current between the poles by the machining power supply device of the electric discharge machine according to the first embodiment of the present invention. The resistance value of the resistor 7 is 1.5Ω which is the same as the characteristic impedance of the power supply line 4, the pulse width T of the output voltage from the power supply 3 is 1.41 μs, and the propagation time Td of the power supply line 4 is 38.
ns. FIG. 2 shows that there is no oscillating current and a smoother machining current flows than in FIG. 14 of the related art.

FIG. 3 is a waveform diagram showing an example of the machining current between the poles by the machining power supply device of the electric discharge machine according to the first embodiment of the present invention. In the condition of FIG. Pulse output (pulse width T = 0.25μ)
s) is shown. FIG. 3 shows that there is no oscillating current and a smoother machining current flows as compared with FIG.

As described above, the switching means 8 is turned on by the control means 9, and the resistance 7 equivalent to the characteristic impedance of the power supply line 4 is connected to the load side of the power supply line 4.
There is an effect that the oscillating current can be eliminated. Control means 9
When the switching means 8 is turned on and the resistor 7 is connected, the resistor 7 becomes the terminal resistance of the feeder line 4 which is a distributed constant line, and the output waveform of the power supply 3 becomes the same waveform regardless of the length of the feeder line 4. Therefore, even if the length of the power supply line 4 varies depending on the type or size of the electric discharge machine, substantially the same machining performance can be obtained.

The influence of the oscillating current on the machining performance is relatively small when the peak value of the machining current is high. Therefore, when the peak value of the machining current is high, the switching means 8 is turned off by the control means 9 to reduce the consumption. An increase in power can be prevented.

When the pulse width of the output voltage from the power supply 3 becomes approximately 1 μs or less, the peak value of the machining current becomes smaller, and the influence of the oscillating current on the machining performance relatively increases. By turning on the switching means 8 and performing processing without the oscillating current, stable processing can be performed. When the pulse width of the output voltage from the power supply 3 is short, the peak value of the machining current is small, and even if the switching means 8 is turned on and the resistor 7 is connected, the power consumption does not increase so much.

In the above description, the case where the coaxial cable 4 is used as the feeder, which is a distributed constant line, has been described, but another distributed constant line such as a twisted pair line may be used.

In the above description, the power supply line is one.
Although the case of a book is shown, a plurality of books may be connected in parallel,
When a plurality of power supply lines are connected in parallel, the characteristic impedance can be reduced, and the processing performance can be improved.

Embodiment 2 FIG. FIG. 4 is a configuration diagram showing a machining power supply device for an electric discharge machine according to a second embodiment of the present invention, and the same reference numerals as those in FIG. 1 of the first embodiment denote the same or corresponding parts. In FIG. 4, reference numeral 10 denotes a capacitor, and a series body of a resistor 7, a capacitor 10, and a switching means 8 having the same characteristic impedance as the power supply line 4 is connected to the load side of the power supply line 4 in parallel with the load L.

FIG. 5 is a waveform diagram showing an example of the machining current between the poles by the machining power supply device of the electric discharge machine according to the second embodiment of the present invention. The capacitance of the capacitor 10 is 0.1 μ
F, the resistance value of the resistor 7 is 1.5Ω which is the same as the characteristic impedance of the power supply line 4, and the pulse width T of the output voltage from the power supply 3 is 1.
41 shows a case where the propagation time Td of the power supply line 4 is 38 ns. FIG. 5 shows that there is no oscillating current and a smoother machining current flows than in FIG. 14 of the related art. Further, it is possible to remove only the vibration component without particularly reducing the peak value of the machining current as compared with FIG.

The smaller the capacitance of the capacitor 10, the smaller the power consumption of the resistor 7 may be. However, when the capacitance of the capacitor 10 is relatively large as shown in FIG. When the constant is relatively large)
Has no oscillating current and a smooth machining current between the poles can be obtained.

FIG. 6 is a waveform diagram showing an example of the machining current between the poles by the machining power supply device of the electric discharge machine according to the second embodiment of the present invention. Is 38n, the same as the propagation time Td.
s (the capacitance of the capacitor 10 is set to 0.0
253 μF) is shown. FIG. 6 shows that there is no oscillating current although there is some distortion.

By setting the capacitance of the capacitor 10 such that the time constant of the series circuit constituted by the resistor 7 is equal to or longer than the propagation time of the feed line 4, the power consumption is small and the distortion is small. A machining current between the poles without vibration can be obtained.

FIG. 7 is a waveform diagram showing an example of the machining current between the poles by the machining power supply device of the electric discharge machine according to the second embodiment of the present invention. This shows a case where a pulse having a pulse width shorter than that of the power supply 3 (pulse width T = 0.25 μs) is output. FIG. 7 shows that there is no oscillating current and a smoother machining current flows as compared with FIG.

FIG. 8 is a waveform diagram showing an example of the machining current between the poles by the machining power supply device of the electric discharge machine according to the second embodiment of the present invention. The case where the time Td is set to 83 ns is shown. FIG.
As can be seen from FIG. 15C of the related art, there is no oscillation current and a smooth machining current flows.

FIGS. 7 and 8 show that FIG.
Even when the propagation time Td of the feeder line 4 is changed as described above (that is, even when the length of the feeder line 4 changes due to a difference in the type or size of the electric discharge machine), the discharge according to the present invention is performed. According to the processing power supply device of the processing machine, it can be seen that there is no change in the waveform due to the length of the power supply line 4 and substantially the same processing current waveform can be output.

Embodiment 3 FIG. FIG. 9 is a configuration diagram showing a machining power supply device of an electric discharge machine according to Embodiment 3 of the present invention, and the same reference numerals as those in FIG. 1 of Embodiment 1 indicate the same or corresponding parts. In FIG. 9, reference numeral 11 denotes an inductor, and a parallel connection of a resistor 7, an inductor 11, and a switching means 8, which are equivalent to the characteristic impedance of the feed line 4, is connected in series to the power supply 3 side of the feed line 4.

FIG. 10 is a waveform diagram showing an example of the machining current between the poles by the machining power supply device of the electric discharge machine according to the third embodiment of the present invention. The inductance of the inductor 11 is 0.1 μH, the resistance value of the resistor 7 is 1.5 Ω, the same as the characteristic impedance of the feed line 4, the pulse width T of the output voltage from the power supply 3 is 1.41 μs, and the propagation time Td of the feed line 4 is 38 ns.
Is shown. From FIG. 10, FIG.
4 shows that there is no oscillation current and a smooth machining current flows.

FIG. 11 is a waveform diagram showing an example of the machining current between the poles by the machining power supply device of the electric discharge machine according to the third embodiment of the present invention. This shows a case where a pulse having a pulse width shorter than that of the power supply 3 (pulse width T = 0.25 μs) is output. From FIG. 11, compared with FIG. 15A of the related art,
It can be seen that there is no oscillation current and a smooth machining current flows.

FIG. 12 is a waveform diagram showing an example of the machining current between the poles by the machining power supply device of the electric discharge machine according to the third embodiment of the present invention. The case where the time Td is set to 83 ns is shown.
From FIG. 12, it can be seen that there is no oscillating current and a smoother machining current flows than in FIG.

11 and 12, even when the propagation time Td of the feed line 4 is changed as shown in FIG. 15 of the prior art (that is, the feed line depends on the type or size of the electric discharge machine). 4), according to the machining power supply device of the electric discharge machine according to the present invention,
It can be seen that there is no change in the waveform due to the length of the machining current, and substantially the same machining current waveform can be output.

[0037]

Since the machining power supply device for an electric discharge machine according to the present invention is configured as described above, it has the following effects.

The machining power supply device for an electric discharge machine according to the present invention can suppress generation of an oscillating current, and can obtain stable machining performance.

Further, the machining power supply apparatus for an electric discharge machine according to the present invention can obtain the same machining performance even when the length of the power supply line is different depending on the type or size of the electric discharge machine.

Further, the machining power supply device for an electric discharge machine according to the present invention can suppress an increase in power consumption.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a machining power supply device of an electric discharge machine according to Embodiment 1 of the present invention.

FIG. 2 is a waveform chart showing an example of a machining current between the gaps by the machining power supply device of the electric discharge machine according to Embodiment 1 of the present invention.

FIG. 3 is a waveform chart showing an example of a machining current between gaps by the machining power supply device of the electric discharge machine according to Embodiment 1 of the present invention.

FIG. 4 is a configuration diagram showing a machining power supply device of an electric discharge machine according to a second embodiment of the present invention.

FIG. 5 is a waveform diagram showing an example of a machining current between gaps by a machining power supply device of an electric discharge machine according to a second embodiment of the present invention.

FIG. 6 is a waveform chart showing an example of a machining current between gaps by a machining power supply device of an electric discharge machine according to a second embodiment of the present invention.

FIG. 7 is a waveform diagram showing an example of a machining current between gaps by a machining power supply device of an electric discharge machine according to a second embodiment of the present invention.

FIG. 8 is a waveform chart showing an example of a machining current between gaps by a machining power supply device of an electric discharge machine according to a second embodiment of the present invention.

FIG. 9 is a configuration diagram showing a machining power supply device of an electric discharge machine according to a third embodiment of the present invention.

FIG. 10 is a waveform diagram showing an example of a machining current between gaps by a machining power supply device of an electric discharge machine according to a third embodiment of the present invention.

FIG. 11 is a waveform chart showing an example of a machining current between gaps by a machining power supply device of an electric discharge machine according to a third embodiment of the present invention.

FIG. 12 is a waveform diagram showing an example of a machining current between gaps by a machining power supply device of an electric discharge machine according to a third embodiment of the present invention.

FIG. 13 is a configuration diagram illustrating a machining power supply device of a conventional electric discharge machine.

FIG. 14 is a waveform diagram showing an example of a machining current between the gaps by a machining power supply device of a conventional electric discharge machine.

FIG. 15 is a waveform diagram showing an example of a machining current between the gaps by a machining power supply device of a conventional electric discharge machine.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 electrode, 2 workpiece, 3 power source, 4 feeder line as distributed constant line, 7 resistor, 8 switching means, 9
Control means, 10 capacitors, 11 inductors.

Claims (6)

[Claims] 1. A machining power supply device for an electric discharge machine for machining a workpiece by supplying machining power between a pole between an electrode and a workpiece. A feed line composed of a distributed constant line for supplying the output of the feed line between the poles, and a characteristic impedance of the feed line connected in parallel with the electrode and the workpiece on the load side of the feed line. A machining power supply device for an electric discharge machine, comprising: a series body of the resistor and the switching means; and control means for controlling on / off of the switching means. 2. A machining power supply device for an electric discharge machine for machining a workpiece by supplying machining power between a pole between an electrode and a workpiece, wherein the power source generates a pulse voltage; A feed line composed of a distributed constant line for supplying the output of the feed line between the poles, and a characteristic impedance of the feed line connected in parallel with the electrode and the workpiece on the load side of the feed line. A machining power supply device for an electric discharge machine, comprising: a series body of a resistor, a capacitor, and a switching means, and control means for controlling on / off of the switching means. 3. The discharge according to claim 2, wherein the capacitance of the capacitor is set such that a time constant of a series circuit formed by the resistor and the time constant is equal to or longer than a propagation time of the power supply line. Processing power supply for processing machine. 4. The electric discharge machine according to claim 1, wherein said switching means is turned on by said control means when an output pulse width of said power supply is about 1 μs or less. Processing power supply device. 5. A machining power supply device of an electric discharge machine for machining a workpiece by supplying machining power between a pole between an electrode and a workpiece, wherein: a power source for generating a pulse voltage; A feed line constituted by a distributed constant line for supplying the output of the feed line between the poles; a resistor, an inductor, and a switching means connected in series to a power supply side of the feed line and having the same characteristic impedance as the feed line. And a control means for controlling on / off of the switching means. 6. A machining power supply apparatus for an electric discharge machine according to claim 5, wherein said switching means is turned off by said control means when an output pulse width of said power supply is approximately 1 μs or less.