JPS61121824A - Electrical discharge machining unit - Google Patents

Abstract

PURPOSE:To improve deep hole machining speed by so constituting an electrical discharge machining unit for making deep holes of minute diameter for optical fiber connector or the like as to cause the generation of the pressure wave in the process liquid in a process liquid path connected to a cylindrical electrode to discharge the process liquid from the end of the electrode. CONSTITUTION:Voltage is impressed to a workpiece 9 and a cylindrical electrode 1 to perform electrical discharge machining with the electrode 1 put into an electrical discharge process liquid 8 to fill the hole of a holder 2 and the electrode 1. Chips 11 are diffused in the process liquid 8. At this time, voltage is impressed to an electrode piece 4 from a power source 7 through brushes 6 and terminals 5 performing electrical discharge to the electrical discharge process liquid 8. This causes the process liquid 8 to make evaporation, i.e., cavitation resulting in generating of pressure wave in a holder 2. This pressure wave makes the process liquid 8 discharge together with chips in a hole being made from the end of the electrode 1. The deep hole machining is thus facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is particularly applicable to optical fiber connectors, fuel injection nozzles, synthetic fiber injection nodules, etc., which have fine holes with a diameter of 10.0 microns to 30.0 microns. The present invention relates to an electric discharge machining device suitable for forming a hole with a depth from several times to more than ten times the hole diameter.

2. Description of the Related Art Conventionally, as shown in FIG. 3, in this type of electric discharge machining apparatus, an electrode 101 is rotatably provided so that a hole can be machined with high precision. A power source 104 is connected to the electrode 101 and the workpiece 103 immersed in the electrical discharge machining fluid 102.
A voltage is applied to the electrode 101 and the workpiece 103 by this power supply 104, and the workpiece 103 is
3 is removed, and a hole larger than the electrode 101 by the discharge gap 106 is machined. The workpiece removed at this time becomes chips and chips and diffuses into the electrical discharge machining fluid 102. However, as the hole gradually becomes deeper, it becomes increasingly difficult to discharge the chips 106, and they accumulate in the electrical discharge machining fluid 106. , short-circuit between the electrode 101 and the workpiece 103. Therefore, normal electrical discharge will not occur and machining will eventually stop.
There was a certain limit to the depth of holes that could be machined.

In order to solve this problem, an electrical discharge machining apparatus as shown in FIG. 4 has been conventionally provided. In this conventional example, a cylindrical electric wire is used.

This cylindrical electrode 107 is communicated with one end of an electrical discharge machining fluid passage 109 via a rotary goo/l/108, and the other end of the electrical discharge machining fluid passage 109 is open to the electrical discharge machining fluid 102. A pump 110 is installed in the middle of the electrical discharge machining fluid flow path 109.
is provided. The electrical discharge machining fluid 02 sucked up by the pump 110 passes through the rotary seal 108 through the flow path 109 and is discharged from the hole 111 of the cylindrical electrode 107. The chips 106 are always discharged from the discharge gap 105 by the discharged discharge machining fluid 102, and do not stay in the machining part. Therefore, the machining speed is improved and deep holes can be easily machined.

Problems to be Solved by the Invention However, when machining a minute hole with a diameter of about 100 to 300 microns, it is necessary to reduce the diameter of the cylindrical electric discharge machining fluid 102. There were problems such as it was difficult to carry out and supply could not be carried out unless the pressure of the pump 110 was significantly increased.

SUMMARY OF THE INVENTION Accordingly, the present invention aims to facilitate machining by ensuring that electrical discharge machining fluid flows through a cylindrical electrode even in a deep hole with a minute diameter of 100 to 300 microns, and to simplify the structure. The purpose of the present invention is to provide an electrical discharge machining device that enables the following.

Means for solving the problems The technical means of the present invention for solving the above problems are as follows:
A cylindrical electrode, an electric discharge machining fluid flow path connected to the cylindrical electrode, and a pressure wave provided in the electric discharge machining fluid flow path to generate a pressure wave in the electric discharge machining fluid in the electric discharge machining fluid flow path. It is equipped with an electric discharge generation part that can discharge electric discharge machining liquid from the tip of the electrode.

Function The present invention can ensure that the electrical discharge machining fluid flows through the cylindrical electrode and prevent chips from accumulating in the electrical discharge gap.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 and 2, the base of the cylindrical electrode 10 is inserted and fixed inside the tip of the holder 2, which is the electrical discharge machining fluid flow path, and the holder 2 and the cylindrical electrode 1 can rotate together. It looks like this.

The holder 2 is made of an insulating material such as ceramic, and a rotating pulley 3 is attached to the outside of the intermediate portion. A pair of metal electrode pieces 4, which are discharge generating parts, are attached to the inside of the intermediate portion of the holder 2, facing each other. A terminal 6 is connected to each electrode piece 4, and each terminal 5 is penetrated through the holder 2 and exposed to the outside.

A brush 6 is brought into contact with each terminal 5, and a power supply T is connected to each brush 6.
is connected.

To use the electrical discharge machining apparatus described above, the cylindrical electrode 1 is immersed in the electrical discharge machining fluid 8, and the holes in the holder 2 and the cylindrical electrode 1 are filled with the electrical discharge machining fluid 8. Then, a voltage is applied to the cylindrical electrode 1 and the workpiece 9 in the electrical discharge machining fluid 8, and the discharge between them creates a hole in the workpiece 9 that is larger than the cylindrical electrode 1 by a discharge gap of 10 minutes. The removed workpiece becomes chips 11 and diffuses into the electrical discharge machining fluid 8. At this time, a voltage is applied to each electrode piece 4 via the brush 6 and the terminal 6 by the power source 7, and discharge is caused via the electrical discharge machining fluid 8. The instantaneous vaporization and cavitation action of the electrical discharge machining fluid 8 accompanying this discharge generate pressure waves in the electrical discharge machining fluid 8 within the Jh router 2 .

This pressure wave is also transmitted to the electrical discharge machining fluid 8 in the hole 12 of the cylindrical electrode 1, and discharges the electrical discharge machining fluid 8 from the tip of the cylindrical electrode 1. By discharging this electrical discharge machining fluid 8, the cutting chips 11 can be removed from the machined hole.

Although the amount of discharge machining fluid 8 discharged due to the discharge between the electrode pieces 4 is small, the hole to be machined is a minute one of 100 to 300 microns, and it is sufficiently effective for removing the chips 11. . In addition, since the amount of discharge machining fluid 8 discharged each time is minute, it is possible to perform a considerable amount of machining with the discharge machining fluid 8 filled in the holder 2 even without supplying the discharge machining fluid 8 one after another. It is. Of course, electrical discharge machining is applied to the upper part of holder 2! It is possible to supply the electrical discharge machining fluid 8 by dropping it, or to supply the electrical discharge machining fluid 8 continuously by providing a valve and a lid, or to use pressure waves more effectively.

Effects of the Invention As is clear from the above explanation, according to the present invention, a cylindrical electrode is communicated with an electrical discharge machining fluid flow path, a discharge generating section is provided in this electrical discharge machining fluid flow channel, and a discharge is generated from this discharge generating section. A pressure wave is generated in the machining fluid by discharging it into the machining fluid, and the fluid is discharged from the tip of the cylindrical electrode.

Therefore, even when machining a deep hole with a fine diameter of 100 to 300 microns, chips can be reliably discharged and machining can be performed easily. In addition, since the discharge generation portion may be provided in the discharge machining fluid flow path communicating with the cylindrical electrode, the structure can be simplified.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the electrical discharge machining device of the present invention, FIG. 1 is a sectional view, FIG. 2 is a perspective view, FIG. 3 is a sectional view of a conventional electrical discharge machining device, and FIG. 4 is a sectional view of a conventional electrical discharge machining device. The figure is a sectional view showing another example of a conventional electric discharge machining apparatus. 1... Cylindrical electrode, 2... Holder (discharge machining fluid flow path), 4... Electrode piece (discharge generating part)
, 6...Terminal, 6...Brush, A...
...Power supply, 8...Electric discharge machining fluid, 9...
...Workpiece, 10...Discharge gap, 11.
...chip, 12...hole. Name of agent: Patent attorney Toshio Nakao and one other name
1 figure

Claims (1)

[Claims] A cylindrical electrode, an electric discharge machining fluid flow path connected to the cylindrical electrode, and a pressure wave provided in the electric discharge machining fluid flow path to generate a pressure wave in the electric discharge machining fluid in the electric discharge machining fluid flow path. An electrical discharge machining device characterized by comprising an electrical discharge generating section capable of discharging electrical discharge machining fluid from the tip of an electrode.