JPS6316925A - Electrode for electric discharge machining - Google Patents

Abstract

PURPOSE:To reduce an unmachined part and improve the efficiency of electric discharge machining by inclining at least one end of a cutting oil feed passage within an electrode toward a machining surface for electric discharge. CONSTITUTION:Electric discharge machining is carried out on proper timing lowering of an electrode 5 for electric discharge having an inclined part 6k wherein the end of a cutting oil feed passage 6 is inclined to a machining surface 5k. In this case, an arc discharge takes place between the tip of a primary unmachined part 2m and the inner wall of the inclined part 6k. As a result, the unmachined part 2m is constrained to be very low due to height determined by the diameter of the inclined part 6k and the inclination angle thereof. Therefore, machining time by an after-treatment device is substantially reduced and electric discharge machining efficiency can be improved. Also, the unmachined part 2m can be eliminated by turning the electrode 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrode for electric discharge machining having a machining oil supply path therein.

[Conventional technology]

FIG. 2 shows a conventional example of an electrode for electrical discharge machining. In the figure,
Reference numeral 1 denotes an electrode for electrical discharge machining (hereinafter referred to as an electrode), which is opposed to the workpiece 2 with a gap g therebetween. Reference numeral 3 denotes a machining oil supply passage, which is formed to pass through the axial center of the electrode 1, and allows machining oil to flow during electrical discharge 1. Reference numeral 4 denotes an electrode holding section that holds the electrode 1.

Next, the action will be explained.

While supplying machining oil to the machining part via the machining oil supply path 3, the workpiece 2 and the electrode 1, which is opposed to the workpiece 2 with a gap therebetween, are used as two poles, and several 10~
When a voltage of several hundred volts is applied to continuously generate an arc discharge, the workpiece 2 facing the electrode 1 is instantaneously melted, and the shape of the electrode machined surface 1 is imprinted on the workpiece 2. .

Therefore, if the electrode l is lowered at an appropriate timing while maintaining a constant distance from the workpiece 2 and continuously generating arc discharge, a hole will be formed in the workpiece 2. Since the moving direction of the electrode 1 and the direction of the machining oil supply path 3 match, the portion of the pressurized body 2 facing the machining oil supply path 3 is left without being subjected to electrical discharge machining, and the remaining portion (the (primary unprocessed part) 2t will protrude from the bottom of the hole (
(See Figure 2).

For example, when using an electrode 1 having a machining oil supply passage 3 with a diameter of 1φ, when the length of the first unmachined portion 2t is approximately 50 mm, the first unmachined portion 2t is the machining oil supply passage. 3
When the oil is poured, it vibrates due to the oil, and the first unknown part 2
Arc discharge occurs between the tip, which is the most deflected part of t, and the inner wall of the machining oil supply path 3, and the first unpressurized part 2t
The discharge is gradually applied from the tip.

When arc discharge occurs between the first unpressurized portion 2t and the inner wall of the machining oil supply path 3, the arc discharge that had been occurring until then stops between the electric current IIfi1 and the pressurized body 2. , the release processing of the portion of the pressurized body 2 facing the electrode 1 does not proceed.

Next, the operation when the diameter of the machining oil supply path is larger than that of the conventional example described above will be explained.

The diameter of the machining oil supply path needs to be increased according to the size of the electrode. When electrical discharge machining is performed using a large 7" pole 1 with a diameter of 5φ and an oil supply passage 3, the portion facing the oil supply passage 3 is subjected to electrical discharge machining, as in the conventional example mentioned above. However, since the remaining portion, that is, the first unprocessed portion 2n, has high rigidity, it is hardly vibrated by the pressurized oil flowing through the processing oil supply path 3.However,
If the machined surface becomes thin like a film on the face where the hole penetrates, the first
Next, the unpressurized part 2n begins to vibrate due to the flowing pressurized oil,
Arc discharge occurs between the tip of the first unmachined portion 2n and the inner wall of the machining oil supply path 3, and discharge heating 7[ is started from the tip. In this case as well, when arc discharge occurs between the first unpressurized portion 2n and the inner wall of the machining oil supply path 3, the arc discharge occurs between the electrode 1 and the workpiece 2, which had been occurring until then. However, the electric discharge machining of the portion of the workpiece 2 facing the electrode 1 does not proceed.

[Problem that the invention seeks to solve]

With conventional electrodes, while the primary unmachined part left in the machining oil supply path 3 is being subjected to electrical discharge machining, the electrical discharge machining of the part of the workpiece 2 facing the electrode 1 does not proceed, so it takes a long time. This has caused a problem in that it has not been possible to meet the recent demand for shortening the addition time.

In addition, when forming a bottomed hole using an electrode having a machining oil supply path with a large diameter, the primary unpressurized portion 2n of the machining oil supply path 3 is There was a problem that the remaining part was left unprocessed (hereinafter, this remaining part is referred to as the second unpressed part).

For example, the second unprocessed part is
Although it can be removed by electrical discharge machining using a post-processing device disclosed in Japanese Utility Model Publication No. 39-18919, in this case as well, there is a large loss of time since the electrical discharge machining is performed by installing the device anew.

This invention was made to solve these problems, and its purpose is to improve the efficiency of electric discharge machining.

(Means for Solving the Problems) The electrode according to the present invention has a machining oil supply passage therein, and at least the end portion of the machining oil supply passage is inclined with respect to the machining surface.

(Function) In the seventh pole according to the present invention, since the end portion of the machining oil supply path is inclined with respect to the machining surface, the first unmachined portion of the workpiece is almost simultaneously exposed to the portion facing the electrode machining surface of the workpiece. Even if the tip part is electrical discharge machined and a bottomed hole is electrical discharge machined, the second
The unmachined area is small, improving the efficiency of electrical discharge machining.

(Embodiment of the invention) FIG. 1 shows an embodiment of the invention. In the figure, 2.
4 and g indicate the same or corresponding parts as in FIG. 5 is an electrode. Reference numeral 6 denotes a machining oil supply passage, which passes through the inside of the electrode 5, passes through its axial center up to the end of the electrode 5, and is inclined at the end with respect to the machining surface 2k. This part is called the inclined part 6. In addition, if the amount of oil supplied to the electrical discharge machining part is uneven, it is preferable to provide a plurality of machining oil supply passages 6.

Since the electric discharge machining electrode 5 of this embodiment has a structure in which at least the end portion of the machining oil supply path 6 is inclined with respect to the machining surface 5k, the electrode 5 is lowered at an appropriate timing of 1F as in the conventional example. However, when electric discharge heating is performed, arc discharge occurs between the tip of the first unmachined portion 2m of the machining oil supply path 6 and the inner wall of the inclined portion 6 of the machining oil supply path 6. It is held down to a height determined by the diameter of the inclined portion 6 and its height.

Even if it is a bottomed hole, the second unknown T part is 2m.
The height is determined by the diameter of the inclined portion 6 and its inclination, and is very low, resulting in a significant reduction in the time required for addition by the post-processing device.

In addition, the discharge pressurization of the second unknown F part uses the electrode 5 of this embodiment instead of t+ of the NJF post-processing device, and this electrode 5 is connected to the second unknown F part and the oil supply path. 6 may be rotated to a position where they do not face each other, and in that state, arc discharge may be caused again between the processed part of the electrode 5 and the tip of the second unknown 4 part, and the electrode 5 may be lowered. .

When the electrode 5 configured as shown in F is rotated around the axis of the electrode 5 from the start of discharge pressurization and lowered at an appropriate timing, a discharge is applied. Since the position is constantly changed, the machining part does not include the primary final machining part. This is suitable for forming a cylindrical bottomed hole.

〔Effect of the invention〕

This invention applies at least the end portion of the weighted oil supply path.
Since the structure is made to be inclined with respect to the above, it is possible to reduce the unapplied portion, which has the effect that the efficiency of discharge pressurization can be improved.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view showing an embodiment of the present invention, Fig. 2 is a partial cross-sectional view showing a conventional example of an electrode for electrical discharge machining, and Fig. 3 shows an unloaded portion that has been subjected to electrical discharge pressure. FIG. 4 is a partial cross-sectional view showing an untreated portion when an electrode having a large-peaked oil supply path is used. In the figure, 5: Electrode for discharge application, 5k: Cutting surface, 6: Applying oil supply path, 6k: Inclined portion. In the figures, the same symbols indicate the same or corresponding parts.

Claims (1)

[Claims] In electrical discharge machining electrodes that have a machining oil supply path inside,
An electrode for electric discharge machining, wherein the machining oil supply path has at least an end portion inclined with respect to a machining surface.