JPH012824A - Electric discharge machining method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an electric discharge machining method in wire electric discharge machining, die-sinking electric discharge machining, and the like.

(Prior Art) In recent years, wire electrical discharge machining has been increasingly used to manufacture mold parts and the like. In this wire electric discharge machining, as shown in FIG. V is applied via capacitor 4. As a result, the capacitor 4 is charged, and at the same time, the wire electrode 2 is moved along the processing line, for example, as shown by the arrow (a).
When the wire electrode approaches the workpiece 3 by moving in the direction, a discharge current flows between the wire electrode 2 and the workpiece 3 as shown in FIG. 4, and the energy due to this discharge current becomes machining energy. After conversion, processing is performed as shown in FIG. Then, when the capacitor 4 is charged again and the wire electrode 2 and the workpiece 3 approach each other, discharge occurs. Therefore, the timing of occurrence of discharge is determined by the relationship between the applied voltage and the moving speed of the wire electrode 2. Furthermore, instead of the method of continuously applying a constant voltage as described above, there is a method of applying a pulse voltage between the wire electrode 2 and the workpiece 3 as shown in FIG. In this method, a discharge current flows when a pulse voltage is applied to perform machining.

However, if the workpiece 3 is a metal with a small resistivity value, the discharge current will flow in a short time of 1 to 3 μs as shown in FIG. For No. 3, the discharge time is very long, 40 μs, as shown in FIG. Therefore, even if the machining energy per discharge is the same as when machining metal, in the case of a workpiece with high resistance, the period until the next discharge becomes longer, so the total machining energy It becomes smaller, and the machining process m becomes smaller. Therefore, if the number of times of tll discharge is forcibly increased in order to increase the number of times of neglect, the M1 rate of transition to abnormal discharge will increase.

For this reason, the electrical discharge machining speed for high-resistance workpieces is extremely slow, making it unsuitable for final mold machining and the like.

(Problems to be Solved by the Invention) As described above, the electrical discharge machining speed for a workpiece having high resistance is extremely slow.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an electric discharge machining method that can perform electric discharge machining quickly and efficiently even on a workpiece having high resistance.

[Structure of the invention] (Means and effects for solving the problem) The present invention processes a workpiece by generating an electric discharge between the workpiece and an electrode such as a wire soaked in a machining fluid. In the electric discharge machining method, a high voltage is applied between an electrode and a workpiece to cause a large discharge current to flow between the electrodes and the workpiece, and the high voltage is automatically applied after a short period of time from the start of this discharge. This is an electrical discharge machining method that attempts to achieve the above objective by cutting off the application.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. Note that the same parts as in FIG. 3 are given the same reference numerals, and detailed explanation thereof will be omitted.

FIG. 1 is a configuration diagram of a wire electrical discharge machining apparatus to which the electrical discharge machining method is applied. A high voltage switching power supply 10 is connected between the wire l1fi2 and the workpiece 3. This high voltage switching voltage 'm10 has a high voltage of, for example, 500~
It has the function of forcibly converting 1000V into a high voltage pulse with a short pulse width by the switching action of a transistor or the like and applying the pulse between the wire electrode 2 and the workpiece 3 in a short period.

With such a configuration, the high voltage switching power supply 10
A high voltage pulse as shown in FIG. 2 is supplied between the wire electrode 2 and a high-resistance workpiece 3 such as conductive ceramics. At this time, when the wire electrode 2 is moved in the direction of arrow (A) and the distance between the wire weight 2 and the workpiece 3 reaches the discharge distance determined by the applied voltage, etc., the distance between the wire electrode 2 and the workpiece 3 is A discharge occurs and a discharge current flows. Thus, energy is converted into machining energy due to this idle current, and electrical discharge machining is performed on the workpiece 3. By the way, as shown in FIG. 2, this high voltage pulse is forcibly cut off 1 to 5 μs after i rises. In other words, the power is forcibly cut off during discharge. As a result, a large amount of discharge N'Ki flows in a short period of time, and this discharge 'iB
Electrical discharge machining is performed by the high machining energy generated by the flow.

In this way, in the above-mentioned embodiment, a high voltage is applied between the wire electrode 2 and the high-resistance workpiece 3, and these wires are connected to each other. A large discharge current is passed between ff12 and the workpiece 3,
Since the high voltage application is forcibly cut off after a short time has elapsed from the start of this discharge, even if the workpiece 3 has a high resistance, it is possible to flow a large current of 1 current, and this large discharge current can be shortened. For example, the number of discharges is 20,000 to 5oo
It can be supplied between the wire electrode 2 and the workpiece 3 at an increase of oo times/second. Therefore, even if the workpiece 3 is a high-resistance material such as a semiconductor or conductive ceramic, electrical discharge machining can be performed quickly and efficiently, and the machining ability can also be improved. In addition,
Although a high voltage is applied between the wire electrode 2 and the workpiece 3, by cutting it off in a short time, there is no effect such as disconnection due to large energy being applied to the wire electrode 2.

Note that the present invention is not limited to the above-mentioned embodiment, and may be modified without departing from the spirit thereof. For example, although the above embodiment is applied to wire electrical discharge machining, the present invention is not limited to this and can also be applied to die-sinking electrical discharge machining.

[Effects of the Invention] As detailed above, according to the present invention, electrical discharge machining can be performed quickly and efficiently even on resistive workpieces. I can provide an electrical processing method.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a wire electrical discharge machining device to which the electrical discharge machining method according to the present invention is applied, FIG. 2 is a diagram for explaining the operation of the device, and FIGS. 3 to 7 are FIG. 3 is a diagram for explaining conventional electric discharge machining. DESCRIPTION OF SYMBOLS 1... Processing liquid, 2... Wire electrode, 3... Workpiece, 10... High voltage switching power supply. Applicant's agent Patent attorney Takehiko Suzue 1-51. Is Figure 2 Figure 3 Figure 4 Figure 5 Figure 6171 f#S7 Figure

Claims (1)

[Claims] In an electric discharge machining method in which a discharge is generated between an electrode such as a wire soaked in a machining fluid and a workpiece to machine the workpiece, a high voltage is applied between the electrode and the workpiece. A large discharge current is caused to flow between the electrodes and the workpiece, and the application of the high voltage is automatically cut off after a short period of time from the start of the discharge.