JPS62114824A - Fine discharge electrode forming device - Google Patents

Abstract

PURPOSE:To improve accuracy in discharge formation of a fine electrode, by approaching finely a forming block whose machining part is narrowly formed in an axial direction of the electrode to an electrode which rotates and shifts in the axial direction, as deforming a parallel spring and detecting the deformed variable. CONSTITUTION:An electrode 1 is attached to a mandrel 2, rotated by a motor 5, moved up and down by a motor 15 via a lever 12, compressing a parallel spring 20 with a screw 24 rotated, and it makes an electrode forming block 26 finely move to the side of the electrode 1, whereby then it comes to the specified gap, discharge forming is carried out by voltage between A and B. Since a form machining part 27 of the forming block 26 is minute in size, the electrode 1 receives no deformation due to machining force, and the electrode 1 moves up and down in a highly accurate manner so that roundness comes so excellent. In addition, since the parallel spring 20 is used for fine motion are nothing at all, and a deformed variable is detected by a displacement gauge so that precision positioning at a submicron unit is performable.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is particularly applicable to nozzles for inkjet printers, which require a machined hole diameter on the order of IO microns and a roundness of submicron precision, and high-precision electron guns for graphic displays. The present invention relates to a micro-discharge electrode forming apparatus suitable for forming micro-discharge electrodes used for electrical discharge machining of micro-holes in apertures, optical fiber connectors, fiber nozzles, automobile fuel injection nozzles, and the like.

BACKGROUND ART In order to realize electric discharge machining of minute holes as described above, it is necessary to establish techniques such as a high-precision electrode rotation mechanism, micro-discharge technology, and a high-precision electrode structure as a processing device. Regarding these techniques, see Japanese Patent Application Laid-open No. 57-33922,
It is shown in 138545 publication, 57-189726 publication, 59-59322 publication, etc. In addition to the techniques described above, a technique for forming the fine discharge electrode according to the present invention is also required.

Conventionally, micro-discharge electrodes are formed by switching the polarity of the discharge circuit on a micro-hole electrical discharge machining device and causing reverse discharge. Molding methods include using the highly precisely polished surface of an electrode molding piece to process and shape the electrode by pressing the surface of the electrode molding piece against a rotating electrode, and forming the electrode by wire cutting. There is a way to do it.

Problems to be Solved by the Invention However, the above-mentioned prior art has the following problems.

In the method of forming using an electrode forming piece, as shown in FIG. Because it is pressed against the electrode 102, it is difficult to accurately read the amount of movement of the micro-movement mechanism of the entire processing tank, and to move the micro-movement mechanism smoothly and accurately without vibration or rattling. Difficult to mold. In addition, in order to mold all the electrodes at once, the surface of the electrode molding device 101 is pressed against the electrode 102, so when molding extremely fine electrodes, the minute resistance of the electrical discharge machining that performs the molding will affect the
Deflection occurs in the electrode 102 as shown by the dotted line in Figure a.

Also, since the electrode 102 is rotated and formed in 1-1, the amount of deflection is a decrease in the diameter of the polarized 102, and the amount of deflection is larger at the tip, so the electrode 102 has a tapered tip with a narrow tip as shown in Figure f4. It becomes like this. Furthermore, the straightness of the electrode @102 also depends on the straightness of the electrode molding part, which is the surface of the molding piece 101, but it is difficult to achieve this straightness, and therefore it is difficult to mold an electrode with good straightness. be.

In the method of forming electrodes by wire-cut discharge, it is difficult to form the electrodes with high precision because the wires are running.

As described above, it is difficult to mold fine discharge electrodes with high precision in the conventional method.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a fine discharge electrode forming apparatus which is capable of forming fine discharge electrodes with high precision.

Means for solving the problems and the technical means of the present invention for solving the above problems are: ``means for rotating the electrode and moving it in the direction of the rotation axis; and an electrode for forming the electrode. An electrode molding piece whose molding part is formed narrowly in the axial direction of the electrode and this electrode molding piece are attached, and parallel four-way grooves are formed from the opposite side of the plate, microscopically extending in one direction. The device is equipped with a deformable parallel spring, means for applying a minute deformation to the parallel spring, and means for detecting the amount of deformation of the parallel spring.

For production The effects of the above technical means are as follows.

That is, first, the electrode is rotated and moved in the axial direction. Next, the parallel spring is slightly deformed to slightly move the electrode forming part of the electrode forming piece toward the electrode side, and the electrode is formed by electric discharge. At this time, since a parallel spring is used as the fine movement mechanism of the electrode forming piece, there is no vibration or wobbling during fine movement, and submicron positioning is possible, and the amount of deformation is detected by the detection means. It is possible to easily form extremely fine electrodes.

Furthermore, since the electrode forming part of the electrode forming piece is narrow, the load on the electrode can be reduced.

This makes it possible to form an electrode with good straightness.

Embodiments Hereinafter, embodiments of the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a partially cutaway schematic front view showing an embodiment of the present invention. As shown in FIG. 1, an electrode 1 is attached to the tip of a mandrel 2. A pulley 3 is mounted on the middle part of the mandrel 2.

A motor 5 is supported on the frame 4, and a pulley 6 is attached to the output shaft of the motor 5. A belt 7 is passed through the hole 8a of the bearing 8 on the pulleys 3 and 6, and the mandrel 2 is brought into contact with the pressure receiving surface 9 of the bearing 8 attached to the frame 4 due to the tension of the belt 7, and rotates in the vertical direction. It is supported so that it can move up and down (move in the axial direction). Therefore, by driving the motor 5, the mandrel 2 and the electrode 1 can be rotated via the pulley 6, bell l-7, and pulley 3. A feed screw 1) is screwed into the support member 10 supported by the pedestal 4 so as to be movable in the vertical direction ζ. A lever 12 is provided above the mandrel 2 and the feed screw 1), and the lever 12 is supported at its intermediate portion so as to be swingable relative to the frame 40. ) Spheres 13, 14 are interposed between them. A motor 15 is supported on the frame 6, and a pulley 16 is mounted on the output shaft of the motor 15. On the other hand, a boot IJ17 is attached to the lower end of the feed screw 1), and a belt 18 is hung around these pulleys 16 and 17. Therefore, by driving the motor 15, the feed screw 1) is moved upward or downward via the pulley 16, the belt 18, and the boot 1j17, and the lever 12 is accordingly swung to move the mandrel 2 and the electrode 1 downward or upward. It is now possible to move it to

A base 19 made of a non-conductive material is attached to the bottom of the frame 4, and one side of a parallel spring 20 is attached to the base 9 by a screw 21.

The parallel spring 20 is a groove 23a that is recessed from the vertically opposite side at a position close to the screw 21 in the steel plate 22.

23b are formed in parallel, and these recessed grooves 23a.

23b, it is possible to be slightly compressed (deformed) in one direction, left and right in the figure (ζ), or to be restored. A feed screw 24 is screwed onto the gantry 4 so as to be movable in the horizontal direction on the free end side of the parallel spring 20, and a sphere 25 is interposed between the feed screw 24 and the parallel spring 20. Therefore, by rotating the feed screw 24, the parallel spring 20 can be compressed or restored.

An electrode forming piece 26 is mounted on the parallel spring 20. This electrode forming piece 26 has an electrode forming part 27 formed in the upper part thereof which is narrow in the vertical direction (in the axial direction of the electrode 1), and the lower part of this electrode forming part 27 is retreated rearward to form a relief part 28.
is formed. In the illustrated example, the electrode forming portion 27 is formed into a sharp edge shape. This electrode forming piece 26 can be slightly moved in the left and right directions in the figure as the parallel spring 20 is compressed as described above. A measuring piece 29 is attached to the parallel spring 20, and this measuring piece 29 moves slightly together with the electrode forming piece 26, and the amount of the fine movement is measured by the displacement meter 3.
It is designed to be measured by 0.

The mandrel 2, that is, the electrode 1, is connected to the electrode forming piece 26 through a brush 31, and to a power source 33 through a capacitor C1 and a charging resistor R, as shown in FIG.
Power is supplied to the electrode forming piece 26, and the polarity of the power source 33 is set so that the electrode 1 end is positive and the electrode forming device 26 end is negative, which is opposite to that for hole machining.

Next, the operation of the above embodiment will be explained. First, power supply 33
The motor 8 is driven to rotate the mandrel 2 and the electrode 1 as described above, and the motor 15 is driven to move the mandrel 2 and the electrode 1 up and down. Next, the parallel spring 20 is compressed by the feed screw 241, and the electrode forming piece 26 is slightly moved toward the electrode 1 side. When the electrode 1 and the electrode molding piece 26 reach a predetermined discharge gap, discharge is started and molding is performed. Therefore, mandrel 2 and electrode 1
Since the electrode 1 is rotating and moving up and down at the same time, the diameter of the electrode 1 decreases over the required length. At this time, while measuring the fine movement of the measurement piece 29 with the displacement meter 30, fine movement feed is applied from the feed screw 24j at a value that is half the difference between the electrode 1 and the target diameter.

FIGS. 3(a) and 3(b) respectively show the forming process by the electrode forming apparatus of the present invention and the electrode shape obtained thereby. As described above, since the electrode forming portion 27 of the electrode forming piece 26 is minute, the electrode 1 is hardly deformed by the processing force. In addition, since the electrode moves with high precision in the vertical direction, the straightness of the electrode is also good. Furthermore, since the parallel spring 20 is used for fine movement of the electrode forming piece 26, there is no vibration or wobbling during fine movement, and submicron positioning is possible.Moreover, since the displacement amount is directly detected by the displacement meter 30, high The electrode diameter can be molded with precision.

In the above embodiment, the electrode forming piece 26 is moved manually, but fine movement may be performed using a drive source such as a motor.

Effects of the Invention As is clear from the above explanation, according to the present invention, the electrode is rotated and moved in the axial direction, and the electrode forming part of the electrode forming piece is formed narrowly in the axial direction of the electrode.
This electrode molding piece forms parallel recessed grooves from the opposite side in the plate material to cause minute deformation in one direction, and the amount of deformation is detected by the detection means.
Molding of electrodes with a diameter on the order of microns can be easily achieved with high precision.

[Brief explanation of drawings]

Figures 1 to 3 show a fine discharge electrode forming apparatus according to an embodiment of the present invention, in which Figure 1 is a partially cutaway schematic front view, Figure 2 is a discharge circuit diagram, and Figure 3 (a) is a molding device. Figure 4 (b) is an enlarged view of the micro-discharge electrode obtained by the present invention, corresponding to the llb section in Figure (a), and Figure 4 (a) is the micro-discharge electrode formed by the conventional micro-discharge electrode forming apparatus. The process explanatory diagram, FIG. 13(b), shows a fine discharge electrode obtained by the conventional apparatus, and is an enlarged view corresponding to section 2b in FIG. 13(a). 1... Electrode, 2... Mandrel, 8... Bearing, 1
)... Feed screw, 20... Parallel spring, 24... Feed screw, 26... Electrode forming piece, 27... Electrode forming processing section, 29... Measuring piece, 30... displacement meter. Name of agent: Patent attorney Toshio Nakao Failed
1 Figure 3 ((:L) m-" 4th world 1/- Dens (b) (b)

Claims (2)

[Claims] (1) A means for rotating the electrode and moving it in the direction of the rotation axis, an electrode forming piece in which the electrode forming part for forming the electrode is narrowly formed in the axial direction of the electrode, and this electrode forming piece. is attached, and a parallel recessed groove is formed in the plate material from the opposite side so that the parallel spring can be slightly deformed in one direction;
A micro discharge electrode forming apparatus characterized by comprising means for applying a minute deformation to the parallel spring and means for detecting the amount of deformation of the parallel spring. (2) The micro discharge electrode forming apparatus according to claim 1, wherein the electrode forming processing portion is formed into a sharp edge shape.