JPS58211824A - Electric discharge machining device - Google Patents

Abstract

PURPOSE:To automatically set the mounting angle of an electrode, by measuring two points on the electrode through a measure provided to an XY table, calculating the mounting angle and correctively rotating the electrode by said angle through an indexing device. CONSTITUTION:A measure 12 is provided onto an XY table 20 of an electric discharge machine, and the table 20 is moved along an X or Y-axis to two points separated by a prescribed distance, then a position of the side face of an electrode 10 in said two points is measured. From this measured value, an angle of the electrode 10 for the X or Y-axis is calculated by a numerical controller 28. Then the electrode 10 is correctively rotated by the angle calculated through an indexing device 16. In this way, the parallel relation between a moving axis of the XY table and the electrode can be automatically set.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric discharge machining apparatus, especially an X
Automatically measure the mounting angle of the electrode with respect to the movement axis of the Y table, and automatically correct the electrode mounting angle based on this measurement value so that the electrode is parallel to the movement axis of the XY table. This invention relates to an electrical discharge machining device with a correction function.

A conventional electrical discharge machining device uses crocin oil, water, or a mixture of water and other substances as a machining fluid between the opposing electrodes and the workpiece 6, and
Electric discharge is generated between the electrode and the workpiece, and this discharge energy is used to machine the workpiece. Conventionally, the work of attaching electrodes parallel to
Using a measuring device such as a dial indicator attached to the table, XY
Move the table appropriately and adjust the rotation of the electrode with respect to the electrode mounting base for a long time while watching the pointer of the measuring instrument to align the electrodes.Use a rectangular electrode to align the electrodes. This was indispensable when performing electrical discharge machining.

However, recently, switching of machining conditions etc. has been automatically performed.
With the advent of electrical discharge machining equipment equipped with a C control device, there has been a demand for speeding up and saving labor in the above-mentioned manual parallelization of electrodes in the setup process.

The present invention has been made in view of the above points, and its purpose is to automatically measure the electrode mounting angle with respect to the moving axis of the XY table on which the workpiece is placed and fixed, and to measure the electrode mounting angle based on this measurement value. It is an object of the present invention to provide an electric discharge machining device having a function of automatically correcting the electrode mounting angle with respect to the mounting base and automatically performing parallel alignment work.

In order to achieve the above object, the present invention interposes a machining liquid between the opposing electrodes and the workpiece, and applies a machining voltage higher than dielectric breakdown between the electrode and the workpiece. In the electrical discharge machining device that generates electrical discharge between the electrodes and performs electrical discharge machining using the electrical discharge energy, an indexing device with a predetermined resolution is attached to the electrode mounting base, and the workpiece is placed and fixed on the XY A probe for parallelizing the electrodes is set up on the top of the table, and the XY table is moved in the direction of the axis of movement perpendicular to the axis of movement at two points located a predetermined distance apart on a line parallel to one axis of movement of the XY table. Move the probe on the XY table to contact the electrode, measure the moving distance from the above two points until the probe contacts the electrode, and compare this moving distance with the above 2 points.
The mounting angle of the electrode with respect to the moving axis of the XY table is calculated from the distance between the points, and the indexing device of the electrode mounting base is driven by the mounting angle to rotate the electrode, and the electrode is automatically connected to the moving axis of the XY table. The present invention is characterized in that an NC control device that automatically controls the electric discharge machining apparatus is provided with a calculation operation function for parallelizing the electric discharge machining apparatus.

In the present invention, a calculation operation is performed to measure the attachment angle of the electrode with respect to a predetermined movement axis of the XY table, and an indexing device is driven by the measurement area to rotate the electrode, so that the movement axis of the XY table and the electrode are parallel to each other. It is preferable that the NC control device has an iterative calculation function that repeats the correction operation twice or more and makes the correction error zero.

Preferred embodiments of the present invention will be described below based on the drawings.

In Fig. 1, 10 is an electrode that is inclined by θ with respect to one of the moving axes of the XY table on which the workpiece is placed and fixed, and 12a indicates the probe at point a. , 12b indicates the position of the probe at point b, which is separated by X from point a. Now, if the measuring tip 12a at point a moves in the Y-axis direction perpendicular to the Y-axis, and the moving distance until it comes into contact with the side surface of the electrode 10 is yI, and the moving distance of the measuring tip 12b at point b is y, then The inclination angle θ of the electrode 10 with respect to the Y axis is θ=
tan ”--(degrees) - Obtained by (1), attach an indexing device with a predetermined resolution to the electrode mounting base of the electrical discharge machining device equipped with an NC control device, and
By equipping the table with the above probe, it is possible to perform NC measurement on a rectangular electrode mounted at an arbitrary angle.
Give commands to the XY table from the control device to move it appropriately, find the travel distance in the X-axis direction and the Y-axis direction until the measuring tip contacts the electrode, and calculate the mounting angle of the electrode from the above formula (1). By using an NC control device to automatically perform arithmetic operations for issuing a rotation command for rotating the electrodes to the angle division device, it becomes possible to automate the parallelization work of the electrodes. Furthermore, it is possible to align the electrodes parallel to the Y-axis in the same way as aligning the electrodes parallel to the Y-axis.
Of course.

Next, parallel alignment of the electrodes will be described when the NC control device of the electrical discharge machining apparatus does not have a trigonometric function calculation function and the calculation of equation (1) is impossible.

If it is assumed that the attachment angle θ of the electrode with respect to the X-axis is θ (1), equation (1) can be approximated by the following equation.

That is, if the electrode mounting angle is 01, then
It is expressed as π. However, the angle θ determined by the above equations (2) and (3) has some error with respect to the true mounting angle. Figure 2 (a) shows the difference between the electrode mounting angle calculated using the approximate formula (3) and the true mounting angle,
In Fig. 2(a), θ is the actual mounting angle of the electrode with respect to the X-axis of the XY table, X is the moving distance of the probe in the X-axis direction (100 u in the figure), and h )'s is a
The difference in the distance traveled in the Y-axis direction from point and point b until the contact point touches the side surface of the electrode, Δθ is the difference between the true mounting angle of the electrode and the angle calculated from the approximate formula (3), and Δy is the distance The position error is indicated by multiplying X by -Δθ. This position error is calculated by calculating the mounting angle of the electrode using the above approximation formula, and when rotating the stain pole using the angle dividing device, the electrode is not parallel to the X axis and rotates by Δθ too much. This means that a positional error of Δy occurs in the Y-axis direction perpendicular to the X-axis between 100w in the X-axis direction of the XY table of the electrodes.

If we temporarily set the electrode mounting angle θ to 10 degrees, the angle error Δθ using the approximate formula is approximately 0.1028 degrees.
If the calculation is performed using an approximate expression and the h1 electrode is rotated and parallelized, the position error Δy becomes a large value of 0.179411J.

Therefore, in order to minimize the error in such rotational parallelization operations of the electrodes, after performing the first calculation parallelization operation using the approximation formula, the same calculation parallelization operation using the second approximation formula is performed. Make sure to do the following. Then, as shown in FIG. 2(b), both the angular error Δθ and the positional error Δy can be made zero.

In this way, even if the NC control device of the electrical discharge machining device does not have a trigonometric function calculation function, the electrode mounting angle can be calculated using the approximation formula described above from the value of the electrode position measured using the probe, and the Repeat the parallel alignment operation of rotating the electrode by the above mounting angle using the alignment device two or more times.)XY
Accurately parallelize the electrode to the table movement axisζ
This can be done automatically.

FIG. 3 shows a schematic configuration diagram of the electric discharge machining apparatus according to the present invention, in which an electrode 10 is held by an indexing device 16 installed on an electrode mounting base 14, and an indexing motor 1
8 rotates the electrode 10 around a predetermined axis. 1
2 is an XY table 2o on which the workpiece is placed and fixed with a measuring head.
When the X-axis drive motor 22 and the X-axis drive motor 24 are operated, they move together with the XY table 20 in the X-axis and Y-axis directions, respectively. Now, NC for electrode parallelization
When the tape 26 is transferred to the NC control device 28, the NC control device 28 appropriately issues a series of commands for the above-mentioned electrode parallelization operation, and first the XY table 20 is operated by the X-axis drive motor 24 as shown in FIG. The probe 12 moves in the Y-axis direction inside the center, stops at the position where the probe 12 contacts the side surface of the electrode 10, and then moves over a distance y.
1 is detected by the X-axis position detector 30 and transmitted to the NC control device 28, and the XY table 20 returns to the movement start point (point a). Next, the X-axis drive motor 22 operates to move the XY table 20 a certain distance (referred to as X) in the X-axis direction in FIG. 3, and stops at point b. 32 and transmitted to the NC control device 28. Thereafter, as described above, the X-axis drive motor 24 operates to move the XY table 20 in the Y-axis direction, stop at the position where the probe 12 contacts the side surface of the electrode 10, and move in the Y-axis direction from point b. The X-axis position detector 30 detects the moving distance y and transmits it to the NC control device 28, and the XY table 20 returns to point a via point b and stops. On the other hand, NC control device 2
8 shows the detected movement distance y1 of the XY table 20,
y3, calculate the mounting angle of the electrode lO to the electrode mounting base 14 with respect to the X-axis direction of the XY table 20 from is rotated in a direction parallel to the X axis to align the electrodes 10 in parallel.

In addition, if the NC control device 28 is not equipped with a trigonometric function calculation function, or if there is a possibility that a position error may occur even if it is equipped with a trigonometric function calculation function, the above-mentioned operation for measuring the mounting angle of the electrode 10 and rotation Repeat the operations in order and complete the NC
When the calculation result of the attachment angle by the control device 28 becomes zero, the parallelization operation of the electrodes 10 is completed.

Incidentally, even in an electrical discharge machining apparatus equipped with an automatic electrode exchange device that automatically exchanges a plurality of electrodes, the distance measurement detection mechanism and calculation function according to the present invention are provided, and the NC control device 2
If 8 is provided with a memory for storing the correction angle of each electrode, the parallel alignment operation of each electrode can be automated.

That is, the angle of the XY table with respect to the X axis with the Nth electrode attached to the indexing device is θN,
Assuming that the angular error after rotating the electrode is θ, and if the angular error with respect to the X-axis becomes zero by repeating the measurement operation and the electrode rotation operation n times, then the correction angle of the Nth electrode is , θN=θN□+θN2+θN3+・-・+θNn
-(4) Then, store this in the memory of the NC control device as the correction angle of the Nth electrode. If you measure such a correction angle for the entire area of the electrodes that are equipped in the same manner and store it in the NC control device, you can adjust the correction angle to that electrode when applying pressure using a predetermined electrode during electrical discharge machining. The parallel alignment operation can be performed automatically by extracting the corresponding correction angle from the memory of the NC control device, transmitting it to the indexing device, and operating the indexing motor.

As explained above, the present invention provides a well-known electrical discharge machining apparatus equipped with an NC control device with an electrode rotation indexing device, a probe, and the like, thereby making it possible to remove electrodes, which had previously been done manually. It is possible to completely automate the parallel alignment operation with respect to the movement axis of the XY table, and it is possible to achieve significant labor savings and automation of setup work in electrical discharge machining.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the positional relationship between the electrode and probe, Figure 2 (a) is a table diagram showing the angular error and position error based on approximate formulas, and Figure 2 (b) is a diagram showing the mounting angle of the electrode and pole. FIG. 3 is a table showing the angular error and positional error when the parallelization operation is performed twice when the angle is 10 degrees, and FIG. 3 is a schematic configuration diagram of the electric discharge machining apparatus according to the present invention. The middle section of each figure is given the same reference numerals, 1o is the electrode, 12
．． 12a and 12b are probes, 14 is an electrode mounting base,
16 is an indexing device, 2o is an XY table, and 28 is an NC control device. Agent Patent Attorney Shin Kuzuno (and 1 other person) Figure 1 Figure 2 (0) (b) Procedural amendment (voluntary) Commissioner of the Japan Patent Office 1, Indication of matter f'l- Patent application No. 57-0785
No. 95 No. 2, Name of the invention: Electric discharge machining device 3, Relationship with the case of person who straightens nails 11 Patent applicant: 1 Location: 2-2-3 Marunouchi, Chiyoda-ku, Tokyo
Name (601) Mitsubishi Electric Corporation Representative Hitoshi Katayama 4, Agent Address 2-2-3-5 Marunouchi 2-chome, Chiyoda-ku, Tokyo, Claims of the specification to be amended, details of the invention Description field. Claims (1) A machining liquid is interposed between the electrode and the workpiece, and a machining liquid is applied between the two objects. In electrical discharge machining equipment that generates electrical discharge and performs electrical discharge machining using this electrical discharge energy, an indexing device with a predetermined resolution is attached to the 1itza, and the measurement for electrode parallelization is carried out on the XY table on which the workpiece is placed and fixed. The XY table is set upright, and the XY table is moved in the direction of the movement axis perpendicular to the movement axis with respect to the electrode at two points separated by a certain distance on a line parallel to the i-direction movement axis of the XY table. Touch the upper probe to the electrode, measure the moving distance from the above two points until the probe contacts the electrode, and use this moving distance and the distance between the above two points to calculate XY.
A calculation operation that calculates the mounting angle of the electrode with respect to the table's movement axis, rotates the electrode by driving the indexing device of the electrode mounting surface plate by the mounting angle, and automatically makes the electrode parallel to the movement axis of the XY table. An electrical discharge machining device characterized in that a function is provided in an NC control device of the electrical discharge machining device, and a probe is provided in the electrical discharge machining device. (2. In the electric discharge machining apparatus according to claim (1), the stop operation for measuring the take-up angle of the electrode with respect to the moving axis of the The NC control device is characterized by having a repetitive arithmetic operation function that rotates the XY table and makes the moving axis of the XY table parallel to the electrode by repeating the correction iE operation twice or more, thereby reducing the correction error to zero. Electrical discharge machining equipment.

Claims (1)

[Claims] (1) A machining fluid is interposed between the opposing electrodes and the workpiece, and a machining voltage higher than dielectric breakdown is applied between the electrode and the workpiece to generate an electric discharge between the electrodes, In the electrical discharge machining equipment that performs electrical discharge machining, an indexing device with a predetermined resolution is attached to the electrode mounting base, and the electrode is placed parallel to the XY table on which the workpiece is placed and fixed. Set up the measuring head for extraction, and move the XY table in the direction of the movement axis perpendicular to the above movement axis relative to the electrode at two points separated by a certain distance on a line parallel to one of the movement axes of the XY table. (7) Place the 'ill constantor in contact with the electrode on the XY table, measure the moving distance from the above two points until the probe contacts the electrode, and use the moving distance and the distance between the above two points to place the 'ill constant on the XY table. Calculation operation function that calculates the mounting angle of the electrode with respect to the moving axis of the XY table, rotates the electrode by driving the indexing device of the electrode mounting base by the mounting angle, and automatically makes the electrode parallel to the moving axis of the XY table. An electrical discharge machining device characterized in that the following is provided in an NC control device that automatically controls the electrical discharge machining device. (2. In the electric discharge machining apparatus according to claim (1), the calculation operation for measuring the attachment angle of the electrode with respect to the moving axis of the XY table, and the rotation of the electrode by driving the indexing device by the measured value) , an electric discharge machining device characterized in that an NC control device is provided with a repetitive arithmetic operation function that repeatedly performs a correction operation to make the moving axis of an XY table parallel to an electrode two or more times, and makes the correction error zero.