JPH0248128A - Electrode guide for electric discharge machining of pore - Google Patents

Abstract

PURPOSE:To improve machining accuracy and profitability by forming a guide hole to guide a necessary electrode for machining so as to be a straight hole having an uniform inner diameter dimension, and forming a slit having narrower width than said inner diameter dimension and extending from said guide hole to the outside radially. CONSTITUTION:When vibration due to rotation is generated on the upper part of a machining electrode 7, this vibration is not transmitted to the lower part of the machining circular electrode 7 forming electric discharge machining gap and electric discharge machining of a pore is accurately and stably performed, as a guide hole 14 is a straight hole. After machining, when the electrode 7 is pulled up by lifting a head 6 and the extreme end part of the electrode 7 is drawn from the guide hole 14 of an electrode guide 10 for electric discharge machining, burr generated on the extreme end part of the electrode 7 is cut off with the guide hole 14 and the burr invades and adheres into the guide hole 14. However, as the guide hole 14 is a straight hole, such metal pieces can be easily removed by inserting through a suitable circular bar-like body, and the guide 10 can be repeatedly used.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a machining electrode guide for electric discharge machining, which is used when making a narrow hole in a workpiece by electric discharge machining.

(Prior art) When attempting to drill a small hole of approximately 0.5 mmφ or less in a workpiece by electric discharge machining, a pipe-shaped electrode is used as the machining electrode, and machining is performed in the discharge machining gap via the pipe-shaped electrode. Generally, electric discharge machines are used in which the pipe-shaped electrode is rotated while a sufficient amount of liquid is supplied, and a machining pulse is applied between the pipe-shaped electrode and the workpiece. In this type of electrical discharge machine, the electrode wears out rapidly, so
A long machining electrode is attached, and a machining electrode guide installed near the workpiece guides the tip of the electrode.
This makes it possible to stably rotate the long processing electrode.

The conventional machining electrode guide used for the above purpose, as shown in FIG. A through hole 23 is formed through the main body portion 21 and the sleeve portion 22 into which a desired pipe electrode 30 for processing is inserted. In this through hole 23, in order to support the rotating pipe electrode 30 for processing,
For example, three support members 24, 25, 26 are provided. These support members are made of a material with excellent wear resistance such as sapphire, and the machining pipe electrode 30, which rotates and moves along the axial direction, is connected to the three support members 24, 25, 25, 24, 25, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 24, 25, 24, 25, 25, 24, 25, 25, 25, 24, 25, 25, 24, 25, 25, 24, 25, 25, 24, 25, 25, 24, 25, 25.
26, it is supported at three points.

(Problems to be Solved by the Invention) The conventional machining electrode guide described above is supported at intervals by support members provided at intervals within the through hole, so that the long machining pipe electrode When the machining pipe electrode 30 swings between the chuck 31 and the machining electrode guide 20 as shown by the dotted line in FIG. 3 due to rotation, this vibration is transmitted downward as shown by the dotted line. As a result, the part of the machining pipe electrode protruding from the machining electrode guide 20 also oscillates as shown by the dotted chain line in FIG. For example, in the case of a pipe electrode for machining with a diameter of 0.2 mm, if its protrusion length is 10 mm, this deflection will be about 70 p at its tip.

For this reason, there are problems in that not only machining accuracy is not achieved, but also the discharge state in the discharge machining gap becomes unstable and the time required for machining becomes extremely long.

Furthermore, as mentioned above, conventional machining electrode guides have a structure in which a support member such as a sapphire guide is placed in the through hole through which the electrode passes. When pulling up the pipe electrode, if the debris generated around the processing pipe electrode is scraped off in the through hole and the guide hole of the processing electrode guide becomes clogged, it is extremely difficult to remove it. The problem is that it is difficult to use, cannot be used, and is not economical.

An object of the present invention is to provide a machining electrode guide for electric discharge fine machining that can eliminate the above-mentioned problems in the prior art.

(Means for Solving the Problems) According to the present invention, in a machining electrode guide for guiding a machining electrode for electric discharge small hole machining, the guide holes for guiding the required machining electrodes are uniform. The guide hole is formed as a straight hole having an inner diameter, and is characterized in that a slit extending radially outward from the guide hole and having a groove width narrower than the inner diameter is formed.

(Function) The processing electrode is guided by a guide hole, which is a straight hole with a uniform inner diameter. This can be easily discharged from the guide hole.

(Example) FIG. 1 schematically shows an electric discharge machine 1 for machining small holes using a machining electrode guide according to the present invention. The electric discharge machine 1 for fine and large machining is a workpiece 4 placed on a machining table 3 in a machining tank 2 filled with machining fluid 40.
This is for forming a narrow hole of, for example, about 1IIIllφ or less at a relatively high speed. The head 6 attached to the column 5 includes a Z-axis feed motor (not shown) and is capable of servo feeding in the Z-axis direction. 1st
In the figure, 7 is a pipe-shaped circular electrode for machining, 8 is a chuck for gripping the circular electrode for machining, and 9 is for rotation for rotating the circular electrode for machining held by the chuck 8 around its axis. It's a motor.

Reference numeral 1O indicates a machining electrode guide according to the present invention, and the machining electrode guide 1O is firmly fixed to an arm 11 provided on the column 5 so as to be movable up and down. The processing electrode guide 10 is positioned above the -F plane level of the workpiece 4 by a required distance.

The circular machining electrode 7 held by the chuck 8 extends straight downward, and is guided by a machining electrode guide lO near its tip.

As shown in FIG. 2, the processing electrode guide 10 includes a main body 12 having a substantially conical shape, and an integrally extending downward coaxially with the main body 12 from the center of the lower surface 12a of the main body 12. A guide hole 14 is formed coaxially with the axis of the main body part 12 and the sleeve part 13. The main body portion 12 and the sleeve portion 13 are made of super steel, and the guide hole 14 may be formed by, for example, electric discharge machining.

The inner diameter of the guide hole 14 is set to be slightly larger than the outer diameter of the circular processing electrode 7 to be used.
Since the hole is a straight hole, the circular electrode 7 for machining is supported and guided by the entire inner circumferential wall of the guide hole 14, and when the circular electrode 7 for machining is rotated by the motor 9, it is connected to the chuck 8 for machining. The deflection of the circular machining electrode 7 that occurs between the machining electrode guide 10 and the machining electrode guide 10 is not transmitted to the electrode portion protruding from the sleeve portion 13 of the machining electrode guide 10.

The processing electrode guide lO is further provided with a slit 15 having a groove width narrower than the inner diameter dimension of the guide hole 14. In this embodiment, the sleeve 15 is formed to extend radially outward from the guide hole 14 and reach the outer circumferential surfaces of the main body part 12 and the sleeve part 13. therefore,
The guide hole 14 is opened along its entire axial direction by a slit 15, and foreign objects such as small metal pieces that have entered the guide hole 14 can be easily discharged to the outside through the sleeve 15.

The advantages of using the processing electrode guide 10 shown in FIG. 2 will be explained with reference to FIG. 1.

By a machining fluid supply device (not shown), machining fluid flows from the end of the circular machining electrode 7 on the chuck 8 side through the inside of the machining circular electrode 7 and is formed between the machining circular electrode 7 and the workpiece 4. Supplied to the electrical discharge machining gap. Circular electrode for processing 7
is rotated around its axis by a motor 9, and as the electrical discharge machining progresses and the electrode wears out, the head 6 descends.
The circular processing electrode 7 is guided by a processing electrode guide 10 and sent downward.

As already explained, since the guide hole 14 is a straight hole, even if the upper part of the circular machining electrode 7 generates vibration due to rotation, this vibration is transmitted to the lower end of the circular machining electrode that forms the electric discharge machining gap. Therefore, electrical discharge machining of fine holes can be performed accurately, stably, and at a high level.

After machining is completed, when the head 6 is raised to pull up the circular electrode 7 for machining and the tip of the circular electrode 7 for machining is pulled out from the guide hole 14 of the electrode guide 10 for electric discharge machining, the machining is completed by electric discharge machining. The burr generated at the tip of the circular electrode 7 is scraped off by the guide hole 14, and the burr enters and adheres to the guide hole 14. However, since the guide hole 14 is a straight hole, this type of metal piece can be easily removed by inserting an appropriate circular rod-shaped body into the guide hole 14, and can also be removed through the slit 15 using a pin gauge or the like. metal pieces can be easily removed.

Therefore, unlike the conventional electrode guide shown in FIG. 3, it can be used repeatedly and is extremely economical.

Furthermore, since the guide hole 14 is opened through the slit 15, the machining fluid can easily penetrate into the guide hole 14 through the slit 15, so that there is a gap between the guide wall of the guide hole 14 and the machining electrode. Since a thin film of 1 is easily formed, the processing electrode can be rotated extremely smoothly.

In Example L, the electrode guide according to the present invention was made of super steel, but it goes without saying that any suitable material may be used.

FIG. 4 shows another embodiment of the machining electrode guide according to the present invention. The processing electrode guide 10' shown in FIG. 4 has a conical main body 41 whose diameter is reduced toward the tip, and a straight guide hole 42 coaxial with the axis of the main body 41 is provided. . The inner diameter of the guide hole 42 is set to be slightly larger than the outer diameter of the processing electrode guided thereby. A plurality of slits 43a, 43b, 4 are formed from the guide hole 42 toward the outside in the radial direction of the main body 41.
3c 43d is formed. In this embodiment, the slits 43 a to 43 d extend a little before the outer circumferential surface of the main body 41 , and each terminal end of the slits 43 a to 43 d has a suitable diameter and is parallel to the guide hole 42 . Through holes 44a to 44d are formed. As in the case of the embodiment shown in FIG. 2, the respective widths of the grooves 43a to 43d have required dimensions different from the inner diameter of the guide hole 42.

According to such a configuration, the number of slits connected to the guide hole 42 can be two or more, so that foreign matter such as small metal pieces in the guide hole 42 can be easily discharged, and the processing Since the liquid can be easily guided into the guide hole 42 through the plurality of slits, the rotating processing electrode can be supported and guided even more smoothly.

By providing the through holes 44a to 44d, foreign matter discharged from the guide hole 42 can be effectively taken out to the outside through the corresponding slits, but these through holes may be provided as necessary. In that case, the slit may be provided in all or part of the slit. Moreover, the number of slits can be one or more and an arbitrary number can be provided. Furthermore, one of the through holes is
As shown by the dotted chain line, it may be connected to the outer circumferential wall of the main body 41 through another slit or the like.

Note that the processing electrode guide 10 shown in FIGS. 2 and 4
．． 10' can be manufactured extremely efficiently by wire cut electrical discharge machining.

(Effects of the Invention) According to the present invention, as described above, it is possible to reduce the swing width of the tip of the machining electrode to be guided, which not only improves machining accuracy but also stabilizes electrical discharge machining. The machining speed can be significantly improved compared to the conventional method.

Furthermore, since the guide hole is a straight hole and a slit is provided, it is possible to easily remove various types of debris generated during processing from the guide hole, making it possible to use the electrode guide repeatedly, which is expected to reduce the running cost of processing. It has special effects such as being able to

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of an electric discharge machine for fine and large machining using the electrode guide for electric discharge machining according to the present invention, and Figure 2 is an enlarged view of the electrode guide for machining of the present invention used in the electric discharge machine of Figure 1. FIG. 3 is a cross-sectional view showing how a conventional machining electrode guide is used, and FIG. 4 is a perspective view showing another embodiment of the machining electrode guide according to the present invention. 10.10'... Electrode guide for processing. 14.42φ...Fist guide hole 15.43a to 43d...Slit patent applicant
Sodick Co., Ltd. Agent Patent Attorney Masatoshi Takano Figure 1 Exit ii/1 Figure 3 Figure 4

Claims (1)

[Claims] 1. In a machining electrode guide for guiding a machining electrode for electric discharge small hole machining, a guide hole for guiding a required machining electrode is formed as a straight hole having a uniform inner diameter size, A machining electrode guide for electrical discharge small hole machining, characterized in that a slit is formed extending radially outward from the guide hole and having a groove width narrower than the inner diameter dimension.