JPS60108229A - Electric-discharge machining device - Google Patents

Abstract

PURPOSE:To improve a degree of positioning accuracy in an electrode, by having a contact signal emitted by a touch probe in a moment that a work and a measurer come into contact with eath other. CONSTITUTION:A touch probe 15 provided with a measurer 16 at its tip is held by a holder 17 attached to a spindle 3 and connected to a numerical control system 13 via a controller 18. When a work 5 contacts the measurer 16, this measurer 16 is slightly tilted to some extent, whereby the touch probe 15 detects the tilt and transmits it as a voltage signal to the NC system 13 via the controller 18, therefore a position of the work 5 is stored in memory, while movements in the work 5 is stopped instantaneously. And, what is more, repetitive accuracy comes to below 1mum without being affected by a finishing state of a reference surface on the work 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electrical discharge machining apparatus, and facilitates the positioning of electrodes.

[Prior art]

Conventionally, as this type of electric discharge machining apparatus, the one shown in FIG. 1 is known. In the figure, reference numeral 1 is a machining tank that stores machining fluid (not shown) and performs electrical discharge machining inside the tank, 2 is an electrode, and 6 is a main phase that performs machining and feeding of the electrode, which is driven by a Z-axis motor 4. be done. Reference numeral 5 denotes a workpiece, and 6td is configured to be movable in the X direction by a table on which the processing tank 2 and the workpiece 5 are attached, and by an X-axis machine 7.

A saddle 8 supports the table 6 and is movable in the Y direction by a Y-axis motor 9. 10 is a head that guides and supports the main shaft, and 11 is the head.
It is a supporting column and is installed on the ped 12. 16 is an NC control device, and cables 14a, 14b
It is connected to the main shaft 6 and table 6 by.

In the electrical discharge machining apparatus configured as described above, the workpiece 5
When positioning the electrode 2 at a predetermined position from the reference plane of the workpiece 5, first, a DC voltage of more than 10 volts is applied from the NC control cape 13 between the electrode 2 and the workpiece 5. The workpiece 5' is moved in the direction in which the reference surface and the electrode 2 come in contact with each other while being slightly moved by the X-axis motor 7 and the Y-axis motor 9.
bring into contact.

At this time, the electrode 2 and the workpiece 5 are short-circuited and the applied voltage becomes zero, a contact display is lit on the Nc control device 16, and the position of the workpiece 5 at that time is recorded. .

Next, the contact state between the electrode 2 and the workpiece 5 is determined by x, y, z.
The workpiece 5 is moved in the X and Y axis directions from the contact position to a predetermined position in the direction in which the workpiece 5 and the electrode 2 face each other, and positioning is performed. Complete the operation.

In this way, in the conventional electric discharge machining apparatus described above, a voltage is applied between the workpiece 5 and the electrode 2, and the contact state is detected only when the voltage becomes zero. Since the positioning is performed by the following method, there is a drawback of the first order.

(1) Depending on the finishing condition of the contact surface of the electrode or workpiece, sufficient current conduction may occur even when contact is made, that is, the applied voltage may not reach zero; therefore, the workpiece may not be connected to the electrode until the applied voltage becomes zero. As a result, indentation etc. occur on the f [pole, which impairs the machined shape and accuracy.

(2) Immediately before the electrode and the workpiece come into contact, a minute electrical discharge occurs between them due to the applied voltage, and a kick mark is created on the contact surface between the two, impairing the 1m machining shape and accuracy.

(3) Due to the above two points, the detection accuracy of the contact position between the smiling electrode and the workpiece is degraded, resulting in an error of about several μm.

[Summary of the invention]

This fourth method eliminates the drawbacks of the conventional method described above, and involves interposing a machining fluid between the opposing electrodes and the workpiece, so that the voltage between the electrode and the workpiece is higher than the dielectric breakdown voltage. In an electric discharge machining device that applies a machining voltage to generate a discharge -+a between the electrodes and performs discharge machining using this discharge energy, it is possible to position the electrode to a predetermined position from the arbitrary point of the workpiece, and to machine the workpiece. In order to measure the dimensions, fixed or polarized dimensions of an object, a touch probe device is equipped that generates a contact signal the moment the workpiece and the constant button come into contact, and the voltage applied between the electrode and the workpiece is The present invention provides an electric discharge machining device that prevents deterioration of the positioning fine line caused by the above and improves accuracy.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. gI
In Fig. J2, the same reference numerals as in Fig. 1 indicate the same or corresponding parts. Reference numeral 15 is a touch probe with a probe 16 installed at its tip, which is held by a holder 17 attached to the main shaft 6 described above. The signal cables 19a and 19b control the N
Connected to Cflll1# device 13.

When the workpiece 5 mentioned above comes into contact with the measuring element 16,
The contact point is slightly tilted, and the tilt of the entire touch probe 1
A differential transformer (not shown) built in 5 detects the voltage and sends it to the controller 18 as a voltage signal. This controller 18 converts the signal into an analog signal and sends it to the NC control device 13, where the NC control device stores the position of the workpiece 5 at that time and stops the movement of the workpiece 5 instantaneously. .

The touch probe 15 can generate a contact signal when only a few tens of grams of force is applied to the end of the probe 16.

Since the lever has a stroke of 10 mm in each of the x, y, and z directions, there is no deformation or damage due to contact, and the contact feed rate of the workpiece 5 is reduced to 100 mm/
Set below s e c and fc:JP! Under the conditions, without being influenced in any way by the finishing condition of the reference surface of the object 5,
Good results have been obtained in which the repeatability of positioning is 1 μm or less.

The amount of positional deviation due to a slight inclination of the probe 16 is less than 5μ, and it shows a constant amount in all three directions regardless of the x, y, and z contact directions, so if the reference length of the block gauge etc. is known in advance. By measuring the object, it is possible to grasp the entire amount of positional deviation, input the numerical value to the full NC control device 16, and automatically correct the measured data, so the measurement accuracy is 1 μm as well as the repeatability. It can be as follows.

Next, other embodiments will be described. FIG. 6 shows a touch glove 15a having a wireless structure, and shown in a state where it is attached to a clamp device 22 attached to the main shaft 6.

In this state, the detection part of the touch probe 15a
15b faces the receiving section 21 installed on the fixture 20 fixed to the head 10 with a gap Gf normally set to about 0.5 to 1.5 mm.

Now, when the end face detection operation of the workpiece 5 is completed, the touch probe 15a is removed from the clamp device 22 by the swing arm 23b of the automatic electrode exchange device 23a fixed to the head 10 and installed in the magazine 23c. The swing arm 23b moves the electrode 2 instructed by the NC control device 16 into the magazine 25. and attach it to the clamp device 22. Thereafter, the workpiece 5 is moved to a predetermined position according to a command from the NC control device 16, and electrical discharge machining is performed.

In the other embodiments described above, since the touch probe body is separated into the detection section and the reception section, it is possible to install an automatic electrode exchange device, and the positioning operation and processing can be performed continuously and automatically. It becomes possible to automate high-precision electrical discharge machining and save labor.

Note that the arrows in Figure 1 indicate the operating directions of the swing arm 2 b and the magazine 23C.

In addition, in the above-mentioned embodiment and other embodiments, the present invention is applied to the positioning of all anodes, but the present invention is not limited to this, and the present invention is not limited to this. Of course, it can also be applied to

〔Effect of the invention〕

As described above, this invention interposes a machining liquid between the electrodes and the workpiece, and applies a machining voltage equal to or higher than the dielectric breakdown voltage between the electrode and the workpiece at the time t mentioned above. In electrical discharge machining equipment that generates electrical discharge between electrodes and performs electrical discharge machining using the radiated energy, it is possible to position the electrode from an arbitrary point on the workpiece to a fixed position n1, measure the dimensions of the workpiece, or measure the electrode dimensions. Because we are equipped with a touch probe device that emits a contact signal the moment the workpiece and the probe come into contact with each other for pressure measurement, we are able to eliminate the drawbacks of conventional devices, such as indentations caused by contact and electrical discharge problems caused by minute discharges. There is no damage, and high precision positioning is possible without being affected by farts in the finish of the contact surface, and as a result, the processing accuracy of the workpiece 5 is dramatically improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional electric discharge machining apparatus t, FIG. 2 is a block diagram showing one embodiment of the present invention, and FIG. 3 is a block diagram showing another embodiment. 2: Electrode, 5: Workpiece, 13: Nc control device, 15.
15a: Touch glove, 15b: Detection unit, 16: Measuring head. Note that the same symbols in each figure indicate the same or corresponding parts. Agent Patent Attorney Sanro Kimura Figure 1 Figure 2 Figure 1

Claims (4)

[Claims] (1) A machining fluid is interposed between the opposing electrodes and the workpiece, and a machining voltage higher than the dielectric breakdown voltage is applied between the electrode and the workpiece to generate an electric discharge between the electrodes. In electrical discharge machining equipment that performs electrical discharge machining using this electrical discharge energy, the workpiece and the measuring device are used to position the electrode from any point on the workpiece to a predetermined position, measure the dimensions of the workpiece, or measure the electrode dimensions. An electrical discharge machining device characterized in that it is equipped with a touch probe that emits a contact signal the moment a child contacts it. (2) Measurable directions lx, y of the touch probe. Claim 1, which is characterized in that each direction of 2.
The electric discharge machining device described in . (3) The detection part and the reception part of the touch probe are separated, and the signal transmission between the two is made wireless by laminated magnetic induction, and the detection part is automatically attached to and removed from the predetermined position of the electrical discharge machine using an automatic electrode exchange device. The electric discharge machining apparatus according to claim 1, wherein the electric discharge machining apparatus is configured to perform the electric discharge machining process. (4) The electrical discharge machining apparatus according to claim 1, characterized in that the speed at which the contact point of the touch probe and the object to be measured come into contact is regulated to 1100 yn/min or less.