JPH0248117A - Wire electrical discharge machining method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a wire electrical discharge machining method that starts machining even if a workpiece and a wire are in contact with each other at a machining start position.

[Conventional technology]

FIG. 4 is a configuration diagram showing, for example, a conventional wire electric discharge machining device, in which (1) indicates a workpiece to be machined;
(2) is a table on which the workpiece (1) is placed and moves freely on the two-dimensional plane of the X and Y axes, and (3) is a jig that fixes the workpiece (1), which is the workpiece, to the table (2). , (4) is a wire electrode, (5) is a machining power supply that applies a machining voltage between the workpiece (1) and the wire electrode (4), and (6) is a table (2).
) X-axis motor moves in the X-axis direction, (7) is a Y-axis motor that drives the table (2) in the Y-axis direction, and (8) is formed between the workpiece (1) and the wire electrode (4). Nozzle that supplies machining fluid (9) k to the machining gap, 00 is the drive control for the xM motor (6) and YM motor (7), and the machining power supply (5)
(2) is a voltage detection device between the workpiece (1) and the wire electrode (4); This is a piece of paper tape with the first NO program of processing perforated.

Moreover, FIG. 5 is a diagram showing the detailed configuration of the NO device αO,
In the figure, t42 is a CRT that displays the status of the wire electrical discharge machining device, t42 is an operation switch that operates the NO device αO, and a board, and t42 is a machining fluid control device that controls the machining fluid device α11. , (foundation) is a processing power supply control device that controls the processing power supply (5), ■ is the X-axis motor (6), Y-axis motor (
7) is a motor control device that controls; (g) is a machining voltage evaluation device that evaluates the voltage obtained from the voltage detection device (6) to determine whether or not there is contact; , a retraction control device that retracts the machining trajectory, releases contact M, and resumes machining, 2) is a paper tape with a No. program punched in it, (g) is a paper tape), memory (not shown), etc. This is an NC program interpretation device that interprets the No program (Kani blog → Muno) given by.

Next, the operation will be explained.

A procedure for machining a workpiece (1) in a one-wire electrical discharge machining apparatus equipped with an NO device αO will be explained. Fix the workpiece (1) on the table (2), and pass the wire electrode (4)k through the large ring drilled in the workpiece (1) in advance to start machining.
) and press the start processing button. No pro)
After interpreting the NO program, the Z-Y system interpreter outputs the first signal for controlling the machining fluid to the machining fluid control device according to the command, and then outputs the first signal for controlling the machining power supply.
Output the signal to the processing power supply control device (b),
A command to move the table (2) is output to the motor control device (2), and the machining is continued by breaking the table (2).

Machining is performed by applying a machining voltage between the wire electrode (4) and the workpiece (1) and using discharge energy generated at that time. Therefore, the distance between the wire l[M(4) and the workpiece (1) must be maintained at a distance sufficient to generate electric discharge. If the wire electrode (4) and the workpiece (1) come into contact with each other, a machining voltage is applied, but no discharge occurs and machining does not proceed. In this case, when contact occurs, the movement command from the No. 1 crumb interpretation device (incorporated) is temporarily interrupted, and a movement command to reverse the machining trajectory is issued from the backward control device O.

As a result, the wire electric FM (4) and the workpiece (1) are relatively separated, contact is released, and discharge occurs again. Next, the machining trajectory is reversed and returned to the starting position f, and the operation of the backward control device θ'i) is completed. Next, machining is restarted by a movement command from the NC program interpreter (incorporated).

[Problem to be solved by the invention]

The conventional wire electric discharge machining method is executed as described above, so if the wire electrode (4) and workpiece (1) are already in contact at the start of machining, there is one trajectory. Therefore, if the contact cannot be released and machining cannot be started, there will be a problem.

This invention is an effort to solve the above-mentioned problems, and provides a wire electrical discharge machining method that can start machining even when the wire electrode and workpiece are in contact with each other at the start of machining. The purpose is to

[First Means for Solving the Problems] The wire electrical discharge machining method according to the present invention includes the steps of determining the contact state between the workpiece and the wire electrode at the machining start point;
If the judgment result indicates that they are in contact, the workpiece and the wire electrode are moved along a preset avoidance trajectory outside the intended processing area to an avoidance position where the workpiece and the wire electrode do not come into contact. After one period of relative movement, the step of meeting the avoidance trace trajectory again from the avoidance position and returning while performing machining to the machining start point, and performing the desired machining from the machining start point; The process consists of a step of carrying out error processing Iy if the contact state does not recover in step 1, and a step of executing the intended processing if the determination result is in a non-contact state.

[Effect]

In this invention, when the workpiece and the wire electrode are in contact at the machining start point, the wire electrode is returned to the avoidance position by following a preset avoidance trajectory while moving the workpiece and the wire electrode relative to each other. After one step, the above-mentioned avoidance soft trace is machined again and traced from the beginning to return to the machining start point.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with respect to meat. 1st
In the figure, the ring is a contact detection device at the start of machining that detects that the workpiece (1) and the wire electrode (4) are in contact at the start of machining, and 6υ is a contact detection device at the start of machining that detects the contact state. In this case, a contact release device at the start of machining that moves to a position where the workpiece (1) and the wire N pole (4) do not contact each other before moving according to the trajectory specified by the NC program, and a contact release device at the start of machining. This is a machining start point return device that moves to a position where the workpiece (1) and the wire tiL pole (4) do not come into contact with each other using the release device 6]) and then returns to the machining start point while performing machining. FIG. 2 is a first diagram illustrating the operation of an embodiment of the present invention. In the figure, ... is the machining start hole, f51) is the machining trajectory specified by the No. program, ■ is the preset T, the first movement trajectory to release the contact, and the ring is the machining start point, and when machining starts The wire electrode (4) is positioned and shows the first position, and the wire connection is completed by the automatic wire feeding device, and the current position also corresponds to this position. FIG. 8 is a complete flow chart explaining one embodiment of the present invention.

The hardware of the wire force discharge machining apparatus in this embodiment is shown in FIG. 4 and is the same as that of the conventional example, so illustration thereof will be omitted. Also, Fig. 4 and conventional example No.
The same reference numerals as in FIG. 5 showing the device a1 indicate corresponding parts, so a description thereof will be omitted.

Next, the operation will be explained. After setting the workpiece (1), the operator passes the wire wire (4) through the machining start wire, saves the NC program, and presses the machining start button. This operation is performed by the step (7C) shown in Figure 3.
Confirmed at t. Normally, at the beginning of an NC program that performs machining, there is a command to turn on the machining power, and the machining power is turned on in accordance with that command. At the start of this process...
- In step (2), contact is determined by the contact detection device (a) at the start of machining, and if there is no contact, the process proceeds to step (c) and machining is performed according to the trajectory of the NC program. This is a normal case in which machining can be performed even with a conventional wire force electric discharge machining device.

As shown in step (2), contact is determined, and in this case, the blade of the contact release device starts operating at the start of machining, as shown in step (2). In this case, conventional wire force/lid discharge machining equipment cannot start machining and
This corresponds to an abnormal case. The contact release device Gυ is set in advance to release the contact at the start of machining.
Move according to the movement trajectory ■ as the Konu's avoidance trajectory.

An example of the movement trajectory 62 is shown in FIG. 2(b) and FIG. 2(0). FIG. 2<b) shows an example of moving radially from the center, and FIG. 2(e) shows an example of moving spirally. In Figure 2, after moving radially in the + direction of X and Y,
One example is shown in which contact is released coincidentally with each machining start hole when moving in the ° direction. If the contact is not released even after moving the T-piece movement path set in advance to release the contact, 9 means STEP (7) The machining will be interrupted as an error as shown strangely. Or, in the case of multiple machining, move to the next machining start hole.As shown in Figure 2, the contact is released when the machining start hole coincides with the machining start hole. Because of this, the step returns to the machining start point using the machining start point return device 6z as shown in 7υ.Here, machining other than one specified in the machine program is performed on the workpiece (1). However, the range is naturally within the range of the first movement locus 62 to release the contact.Therefore, the movement trajectory should be set within the range allowable for the machining. In this case, machining will not be performed on any part of the workpiece (1) other than the intended one.In this way, machining is performed for each machining start hole, and then the boss Machining is performed according to the trajectory of the program.

The subsequent operations are equivalent to conventional wire force, electric discharge machining equipment.

In addition, in the above embodiment, an example is shown in which the operator passes the wire electrode (4) through the machining start hole and sets it. The same effects as in the above embodiment can also be achieved.

Although the above embodiment shows an example in which machining is started from the machining start hole, the same effects as in the above embodiment can be obtained even when machining is performed from the end face.

Furthermore, although the above embodiment shows an example of machining one hole, even in the case of machining multiple holes, the same effect as in the above embodiment can be achieved for each machining start hole.

〔Effect of the invention〕

As described above, according to the present invention, if the wire electrode and the workpiece are already in contact at the start of machining, the wire electrode moves until the contact is released, and after 1 minute after the contact is released, it returns to the machining starting point. Conventionally, it was difficult to start machining, but machining can be started even when contact occurs at the start of machining, and wire force... This has the effect of greatly improving the operating rate and operability of electrical discharge machines.

[Brief explanation of the drawing]

Fig. 1 is a detailed configuration diagram showing a wire electric discharge machining snow making device according to an embodiment of the present invention, Fig. 2 is a diagram showing a movement locus of a wire electrode according to an embodiment of the present invention, and Fig. FIG. 4 is a block diagram showing the conventional wire electric discharge machining apparatus; FIG. 5 is a detailed block diagram showing the NC device of the conventional wire electric discharge machining apparatus. In the figure, (a) is a contact detection device at the start of machining, Q5]
) is a contact release device at the start of machining, 62 is a machining start point return device, . . . is a machining start hole, 61) is a machining locus, 62 is a movement locus, and the ring is a machining start point. In addition, in the figures, the same symbols indicate the same or equivalent parts.

Claims (1)

[Claims] A step of determining the contact state between the workpiece and the wire electrode at the processing start point, and if the determination result is that the wire electrode is in contact,
Following a preset avoidance trajectory outside the intended machining area, the workpiece and wire electrode are relatively moved to an avoidance position where the workpiece and wire electrode do not come into contact, and then the avoidance is performed from the avoidance position. Following the trajectory again, performing machining and returning to the machining start point, executing the desired machining from the machining start point, and executing error processing if the contact state is not recovered at the avoidance position. and the step of
A wire electrical discharge machining method comprising the step of executing a desired machining when the determination result is a non-contact state.