JPS6144536A - Working for minute hole and apparatus thereof - Google Patents

Abstract

PURPOSE:To work a minute hole finely by shaping an electrode material fitted onto the electrode holder of an NC-type spark erosion apparatus for working hole into an electrode for working hole by a wire spark erosion apparatus and working the workpiece without demounting the workpiece from the holder. CONSTITUTION:An electrode material 15 is fitted onto an electrode holder 6, and said holder 6 is shifted in the Y-direction by using the NC apparatus of an NC- type electric-discharge hole working apparatus 1, and said material 15 is set oppositely to a wire electrode 7 part on a guide 14. At this time, the position in the Y-direction of the material 15 is correctly controlled according to the diameter of the worked hole, and electric discharge is generated between the electrode 7 part and the material 15, and electric discharge machining is carried-out by shifting the material 15 in the Z-direction, revolving around the revolution axis line of the holer 6, and the electrode 7 is always traveled during the electric discharge machining in order to carry-out electric discharge always on a new part, and thus an electrode with high accuracy is obtained and correctly fitted onto the holder 6, and a hole having a correct diameter is worked at the correct position on a workpiece 3.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and apparatus for machining microholes by electrical discharge machining, and particularly to a method and apparatus using numerical control.

(Conventional technology) For example, a printer's inkjet nozzle.

In fixed plugs for optical fibers, fuel injection nozzles for engines, etc., it is required to precisely machine fine holes of various diameters. Such fine holes are usually machined by electrical discharge machining. Recently, numerical control (hereinafter referred to as NC) has come to be employed in such electrical discharge machining.

In an NC electrical discharge machining device, an electrode holder is generally placed in the X direction, the Y direction, and the table having an x-Y plane.
The electrode holder is relatively movable in the Z direction perpendicular thereto, and the relative position of the electrode holder is controlled by an NC device. Nowadays, the position of the electrode holder can be controlled very precisely.

On the other hand, with regard to electrical discharge machining itself, the machining accuracy can be made extremely high by using a wire electrode that is run by a feeding and winding mechanism. Therefore, electric discharge machining is now performed using a wire electrode as a hole machining electrode for machining the above-mentioned fine holes.

(Problems to be Solved by the Invention) By the way, even if the machining position of the high-precision hole machining electrode manufactured in this manner is controlled by an NC electric discharge machining device, the electrode may not be connected to the electrode holder. If the hole is not properly attached, accurate hole machining will not be possible. For this reason, conventionally, it was necessary to completely remove metal powder, dust, etc. adhering to the electrode holder before attaching the electrode, which required a great deal of effort. Moreover, even if careful attention is paid, it is difficult to align the axis of the electrode completely with the axis of rotation of the electrode holder.

The present invention has been made in view of such problems, and its purpose is to enable a high-precision electrode to be mounted in alignment with the rotational axis of the electrode holder, thereby:
The purpose is to enable precise processing of minute holes.

Another object of the invention is to make the processing completely systematic.

(Means for solving the problem) In order to achieve this objective, the present invention provides a
C. An electrode material is attached to the electrode holder of the electrical discharge machining device, and the electrode material is formed into a hole machining electrode using the wire electrical discharge machining device, so that the workpiece can be machined without removing the formed electrode from the electrode holder. I have to. The wire electrical discharge machining device is provided within a relatively movable range of the electrode holder,
The electrode is processed using an NC device for hole processing. Electric discharge for processing the electrode is performed at or near the contact portion of the traveling wire electrode with the guiding and supporting guide.

(Operation) The electrode material mounted on the electrode holder is controlled by the NC device of the NC electric discharge machining device for hole machining, and is formed into a high-precision electrode by the wire electric discharge machining device. The molded electrode then precisely aligns with the rotational axis of the electrode holder. Therefore, if the workpiece is machined by controlling the position using the NC device, a hole with an accurate diameter will be formed in the workpiece at an accurate position.

Moreover, by simply attaching the electrode material to the electrode holder and setting the workpiece, the entire process from forming the electrode to drilling holes in the workpiece can be performed by NC.

(Example) Hereinafter, the present invention will be explained in detail based on the drawings.

1 to 3 show an embodiment of a microhole processing device according to the present invention, and FIG. 1 is a schematic perspective view showing the overall structure thereof;
FIG. 2 is an explanatory diagram of a wire electrical discharge machining device incorporated in the microhole machining device, and FIG. 3 is a detailed diagram of a wire electrode guide portion of the wire electrical discharge machining device.

As shown in Fig. 1, this microhole processing device
It consists of an NG type electrical discharge hole machining device 1 and a wire electrical discharge machining device 2. These processing devices 1 and 2 share a processing power source. The NC type electric discharge hole machining apparatus 1 is similar to a normal NC type electric discharge hole machining apparatus, and includes a table 4 on which a workpiece 3 is installed, and a table 4 that is fixed to the side of the table 4 and extends above the table 4. A fixed frame 5 having an electrode holder support portion 5a is provided. The table 4 has an x-y plane on which the workpiece 3 is placed, and is movable in the X direction. Further, the electrode holder 6 is mounted on the electrode holder support portion 5a of the fixed frame 5.
It is supported so as to be movable in the Z direction perpendicular to the direction and the XY plane, and is configured to be rotated around a rotation axis in the Z direction. In this way, the electrode holder 6 is movable relative to the table 4 in the X direction, Y direction, and Z direction. Such relative movement of the electrode holder 6 is accurately controlled by an NC device (not shown) according to a program.

Wire electrical discharge machining equipment! ! 2, as shown in FIG. 2, the wire electrode 7 is run by a wind-up @@11 consisting of a wire pobbin 8, a wind-up pinch roller 9, and a wind-up pobbin 10; A suitable tension can be applied to the tension adjustment mechanism 12. This wire electrode 7 is connected to appropriate auxiliary guides 13, 13 . ... to a wire electrode guide 14 fixed to the front surface of the fixed frame 5 of the electric discharge hole machining apparatus 1, as shown in FIG. As is clear from FIG. 3, this guide 14 is formed in the shape of an abacus ball, and a guide groove 14a is formed on its outer periphery, and the wire electrode 7 is inserted into the guide groove 14a.
It is designed to be guided and supported while sliding along.

This guide groove 14a is shallower than the diameter of the wire electrode 7, and when the wire electrode 7 is supported along this groove 14a, the outer periphery of the wire electrode 7 protrudes from the guide 14. The guide 14 is provided within the range in which the electrode holder 6 is moved, and discharge occurs between the portion of the wire electrode 7 supported in contact with the guide 14 and the electrode material 15 attached to the electrode holder 6. It is becoming more and more popular.

Note that the guide 14 can also be rotatably supported by the fixed frame 5. In this case, the frictional resistance between the wire electrode 7 and the guide 14 is reduced, so that the wire electrode 7 can be smoothly fed out and rolled up.

In the microhole machining apparatus configured as described above, when a microhole is to be machined in the workpiece 3, the workpiece 3 is first set on the table 4, and then the electrode material 15 is attached to the electrode holder 6. , N of NC type electric discharge hole machining device 1
The electrode holder 6 is moved in the Y direction using the C device, and the electrode material 15 is opposed to the wire electrode 7 portion on the guide 14. At this time, the position of the electrode material 15 in the Y direction is accurately controlled according to the required diameter of the hole machining electrode, that is, the diameter of the hole to be machined. Then, at that position, the wire electrode 7
A discharge is caused between the part and the electrode material 15, and the electrode material 1
5 is not rotated around the rotational axis of the electrode holder 6 but is moved in the Z direction to perform electric discharge machining. During this electric discharge machining, the wire electrode 7 is constantly moved by the feeding and winding mechanism 11. Ensure that the discharge always takes place in a new area. Since the diameter of the wire electrode 7 is determined with high precision, it is possible to obtain an electrode with extremely high precision.

The electrode formed while being rotated around the rotational axis of the electrode holter 6 in this manner has the following characteristics in its finished state:
Its axis always coincides with the rotational axis of the electrode holder 6. That is, the electrode is correctly attached to the electrode holder 6.

Therefore, with the molded electrode attached to the electrode holder 6, the electrode holder 6 is moved relative to the table 4 in the X direction and the Y direction, and a discharge is caused between the electrode and the workpiece 3. When electrical discharge hole machining is performed on the workpiece 3, the position of the electrode holder 6 is controlled by the NC device in the same manner as a normal NC electrical discharge machining device, so that the positioning is also performed extremely accurately. In this way, a hole with an accurate diameter is machined in the workpiece 3 at an accurate position.

The feeding polarity of the electrode material 15 and the wire electrode 7 during electrode forming, and the feeding polarity of the electrode and workpiece 3 during hole machining can be switched by an NC device according to the respective materials and the like.

In the above embodiment, the guide 14 in the part where the wire electrode 7 is caused to generate electric discharge is shaped like an abacus bead.
The guide 14 is a wire electrode 7 on which the discharge occurs.
It may be of any shape as long as it allows accurate positioning of the part. FIG. 4 shows another embodiment of such a guide 14. In this example, the guide 14 includes a guide member 14b that is oval in plan view, and a pair of auxiliary guide members 14c that sandwich the guide member 14b from above and below.

The guide surface (the outer peripheral end surface on the left side in the figure) of the guide member 14b has a thickness smaller than the diameter of the wire electrode 7, and is configured to protrude from the auxiliary guide member 14c. The portion of the guide member 14b sandwiched between the auxiliary guide portions 'JfA14c is made slightly thicker than the diameter of the wire electrode 7, so that the wire electrode 7 is guided and supported between the auxiliary guide members 14c. By doing this, the wire electrode 7 can be accurately positioned and held in a state where it protrudes from the guide 14, and discharge can be caused in that part.

If the part of the wire electrode 8i7 that is discharged is the part that is contacted and supported by the kite 14 in this way, its position will not change even when the wire electrode 7 runs, and the electrode can be formed with high precision. It becomes like this. However, if it is very close to that point, there is practically no problem.

The wire electrode guide 14 of the wire electrical discharge machining device 2 does not have to be provided at a fixed position;
It can also be provided on a movable part, for example on the table 4, as long as the relative positional relationship between the discharge part of the wire electrode 7 supported thereon and the electrode holder 6 is known. Further, the present invention can be applied to a device in which the electrode holder 6 is fixed and the table 4 is moved in the X direction and a Y direction, or a device in which the table 4 is fixed and the electrode holder 6 is moved in the X direction and the Y direction.
It is obvious that it can be applied to various types of NC-type electrical discharge hole machining equipment, such as one in which the frame 5 supporting it is moved in the X direction and the Y direction. 4 and the electrode holder 6 may be controlled only in either the X direction or the Y direction.

(Effects of the Invention) As is clear from the above description, according to the present invention, the electrode for hole machining is formed while it is attached to the electrode holder for hole machining, so that the electrode can be accurately shaped. This prevents errors from occurring when attaching and detaching the electrode, and eliminates the need to strictly consider the inclination of the electrode material when attaching it to the electrode holder.
The work will also become easier.

In addition, the hole machining electrode is formed by wire electrical discharge machining, and the electrical discharge is carried out at the part supported in contact with the wire electrode guide, or at least in the vicinity thereof. The discharge position during molding can be made almost unchanged. The position of the electrode material during electrode molding is controlled using the NC device of the NC-type electrical discharge hole machining device, making it possible to mold electrodes of various diameters with extremely high precision. . Further, if necessary, electrodes with complex shapes such as tapered or stepped electrodes can be easily formed.

In this way, fine holes of various diameters can be precisely machined in the workpiece. Moreover, the operator only needs to attach the electrode material and set the workpiece, and the rest can be done automatically according to the program, from electrode forming to hole drilling, eliminating the need for advanced skills. Can be done.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing an embodiment of a microhole machining device according to the present invention, FIG. 2 is an explanatory diagram of a wire electric discharge machining device incorporated in the microhole machining device, and FIG. The wire electrode guide portion of the wire electric discharge machining device is shown in which (a) is a side view, (b) is an enlarged vertical sectional view of the main part, and FIG. 4 is another implementation of the wire electrode guide portion. An example is shown in which (a) is a longitudinal sectional view, and (b) is a plan view. 1... NC type electrical discharge hole machining device 2... Wire electrical discharge machining device 3... Workpiece 4... Table 6...
・Electrode holder 7...Wire electrode 11...
Feeding and winding mechanism 14...Wire electrode guide 15...Electrode material

Claims (4)

[Claims] (1) The step of mounting the electrode material 15 on the electrode holder 6 of the numerically controlled electrical discharge hole machining device 1, and the step of attaching the electrode material 15 to the electrode holder 6 of the numerically controlled electrical discharge hole machining device 1. Electrode guide 14
and forming the attached electrode material 15 into a hole machining electrode using the wire electrical discharge machining device 2, and numerically controlling the electrode holder 6 with the formed electrode attached. A method for machining microholes, comprising sequentially performing the following steps: , performing discharge hole machining on a workpiece 3 . (2) a table 4 having an X-Y plane for installing a workpiece; an electrode holder 6 movable relative to the table 4 in the X direction and in the Z direction perpendicular to the X-Y plane; A numerical control device for controlling the relative position of the electrode holder 6 with respect to the table 4; A wire electrical discharge machining device 2 is provided, which includes a wire electrode 7 where electrical discharge occurs between the wire electrode 7 and a material 15, and a wire electrode guide 14 which contacts and supports the wire electrode 7 at a portion where the electrical discharge occurs or a portion adjacent thereto. A micro-hole processing device. (3) Electrode holder 6 of the numerically controlled electrical discharge hole machining device 1
3. The microhole processing device according to claim 2, wherein the microhole processing device is also movable relative to each other in the Y direction. (4) Electrode holder 6 of the numerically controlled electrical discharge hole machining device 1
The microhole processing device according to claim 2, wherein the microhole processing device is rotatable around an axis in the Z direction.