JPS63105837A - Wire cut electric discharge machine - Google Patents

Abstract

PURPOSE:To improve machining precision at a corner part, by providing a control device which predicts a change in a machining amount at a corner part and corrects a charge in a gap between the sides of electrodes occas ioned by a change in a machining amount. CONSTITUTION:A discriminator 12 discriminates whether, in finish machining, a present machining position is under circular movement of a corner part, and transmits a signal, by means of which a control device 14 is actuated, when it is under circular movement. A discharge gap amount during linear machining under each machining conditions and a machining amount during linear machining determined by an electrode shift amount are stored in a memory 15. A computer 16 calculates a machining amount at a corner part based on information from the memory 15, and information, e.g. the radius of a corner, the size of an electrode. A computer 17 calculates a correction amount of the program radius of a corner part, based on the calculating result of the computer 16, so that a shape after machining forms a desired shape even if a change in a machining amount occurs. By means of a signal from the discriminator 12 and from the calculating result of the computer 17, the control device 14 controls a control device 11 so that an actual machining locus is coincided with movement on a desired correction locus.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wire cap electrical discharge machine, and particularly to improving g precision thereof.

[Conventional technology]

- Figure 2 is a schematic diagram showing the configuration of a conventional wire cap electrical discharge machine, in which (1) is a wire-shaped 7 poles, (2) is a workpiece, and (3) is a workpiece (2). The X slider moves the workpiece (2) in the left and right directions in the figure, the Y slider (4) moves the workpiece (2) in the front and rear directions in the figure, and (5) the X slider (3)
), (6) is the Y slider (4).
) is the servo motor that drives 1, (7) is the servo motor that drives the servo motor (5
), (8) is a servo amplifier that supplies a current to the servo motor (6), and (9) is a servo amplifier that supplies a current to the servo motor (6). A machining W source that supplies voltage, αO is a detector that detects the average machining voltage between the wire-shaped electrode (1) and the workpiece (2), αD
1 is a control device that controls a caustic amplifier (788) based on a signal from a detector αG and a predetermined program. The wire-shaped electrode (1) is run at a predetermined speed, and a pulsed voltage is applied from the processing irm (9+) between the wire-shaped electrode (1) and the workpiece (2), thereby forming the wire lying mold 1). Machining is performed by generating electrical discharge between the workpieces (2). At that time, the program trajectory ζζ given to the control device αυ in advance
Based on this, a command signal is sent to the servo amplifier (7) (81), and the signal causes the servo motor (5) < 6) to
By driving the slider (3) and Y slider (4), it will be possible to process the desired shape.Generally, the process condition changes from time to time, so the control body wire-like flf by the average voltage of
The X slider (3) and Y slider (4) are driven at an optimal feed rate so that the machining gap between i (1) and the workpiece (2) is constant. Normally, it is possible to obtain a good shape and surface roughness by performing end face finishing several times after rough machining. By the way, the shape accuracy after finish machining is determined by the W pole side gap, and in order to perform high precision shape machining, this 1M
It is necessary to keep the polar hearing loss constant. Figure 8 shows
This is due to the enlargement of the wire-shaped electrode (1) and workpiece (2) during finishing machining, but in conventional general constant average voltage control, the machining speed σ decreases when the amount of material to be removed increases. As a result, the processing integral effect on the wire side portion (portion A in the figure) increases, and the electrode side gap G8 increases. Namely, machining electrical conditions and average servo! Even if the diameter is the same, if the depth fiL changes, the electrode side gap will not be constant and the shape accuracy will deteriorate after machining. This shows the relationship between the width fiL and the electrode side gap Gs.
Is it big? I can see that you are depressed. , 5j! During the final shape machining, the maximum change in take-out n1iL is at the corner, and Figure 5 is an enlarged view of the wire shape 11r4@(1) and workpiece (2) during in-corner finishing machining. It is a diagram. ■Amount removed during 11rfa machining ('LO,
Is the amount of storage at the corner (L2-L4) considerably larger than L5)? It can be seen that Figure 6 is a diagram showing the change in the take-off at the inside corner, and shows a certain distance M (H1 in the diagram) before reaching the inside corner.
Ka9 Tori JiL begins to increase and becomes a constant truth, and Ka9 Tori JiL starts to increase and becomes a certain distance (H8 in the figure) before the end point of the corner part.
L begins to decrease and returns to the amount removed in the 1-line machining section.

Therefore, as explained earlier, especially in the inner corner part^
Well settled! As the W pole side gap GS increases as kL increases, the shape after processing deteriorates significantly (Figure 7).
Furthermore, at the outer corners, the f ultra-fine one-plane gap Gs decreases as the removal tL decreases, so the shape after processing is similarly inferior.

[Openings that the invention seeks to solve]

Since the conventional wire cupto straightening machine is configured as described above, the gap between the wire electrode sides becomes 1 due to changes in the removal amount, especially at corners, etc., and as a result, the accuracy of the shape after processing deteriorates significantly. There were problems such as.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a wire-cut electrical discharge machine that significantly improves machining accuracy at corner portions.

[Means for solving problems]

The wire-cut electric discharge machine according to the present invention is equipped with a control means that predicts in advance the cutting process at a corner portion and corrects a change in the electrode side gap due to a change in cutting position.

[Function] In the present invention, the means for predicting the change in the number of corner parts rJ is a control that corrects the change in the electrode side gap due to the change in the removal amount based on information given in advance and information indicating the current machining position and situation. Operate the equipment to improve machining accuracy at corners.

[Embodiments of the invention]

An embodiment of the present invention will be described below based on Embodiment 1.

In FIG. 1, (1) is a wire-shaped stomach tffi, (2)
is the workpiece, (3) is the X slider that moves the workpiece (2) in the horizontal direction in the figure, and (4) is the Y slider that moves the workpiece (2) in the front and rear directions in the figure. , (5) is X,
Drive the X Rider (3) through the pass - Bomota, (6) is Y
Slider (4) e is driven by a servo motor, (7) is a servo amplifier that supplies 7 currents to the servo motor (5), and (8)
) is a servo amplifier that supplies a current to the motor (6), (9) is a processing power supply that supplies a bus voltage between the wire-shaped actual pole (1) and the workpiece (2), and QO is a detector that detects the average machining voltage between the wire electrode (1) and the workpiece (2); ) is the control wJ device that controls the machine, α is the first discriminator that determines whether the machining position is in the corner circular arc shape or not, and (to) is the memory that stores the previously anticipated pick-up for straight-line machining. A memory, αG, is an operator that calculates the change in the amount taken at the corner from the information in the memory, and αη is an operator that calculates the amount of correction of the program trajectory at the corner with respect to the change in the loss amount. This is a control device that controls the error 1 of the corrected trajectory from the signal of α41+imaginary discriminator (2) and the calculation result of arithmetic unit aη.

Next, p operation jζ of the embodiment of the present invention will be explained.

Similar to the conventional example, the wire-shaped electrode (1) runs at a predetermined speed.
, from processing 11J (9), one pulsed pressure is applied to the wire-shaped electrode (
1) and the workpiece (2), a lightning bolt is generated between the wire-shaped T pole (1) and the workpiece (2) to perform processing. given to
Servo amplifier (7) (8) based on the programmed trajectory
17 A command signal is transmitted, and the signal causes the servo to
E: -ta (5) (8) KaXs? , (,51”−(3)
Oh! Hey, r, ? The control device (6) drives the cutter (4) to process the desired shape, and the wire-shaped electric current tl@ is detected by the detector αQ and the average voltage of the horizontal opening
In order to keep the machining gap between (1) and workpiece (2) constant,
X7 at optimal feed speed. By driving the rider (3) and Y slider (4) and performing end face finishing several times after rough machining, better shape accuracy and surface roughness can be obtained. As mentioned above, the shape accuracy after finishing is determined by the gap between the side surfaces of the electrode, and in order to perform high-precision shape machining, it is important to make the entire gap between the surfaces of the electrode (I'11).

During finishing machining, the discriminator (2) determines whether the machining position of the machining machine is in the middle of a corner arc adjustment or not, and when the corner part is in the process of completing a corner arc, it sends a signal to operate jliI+Osenku. do. In addition, the memory is calculated from the several hundred gap JJ7, 1r pole shift amount (difference between the off-theft on the previous W cutting surface and the off-theft of the additional work) during straight line machining under each machining condition, and the yield amount during straight line machining is Memorize 1
The operator α0 is the information in memory (to) and the corner radius, Wl? Based on the information such as the diameter i, the loss at the corner (the total of L21 in Figure 3) is 1. 77i]: The control device α receives the signal p from the discriminator (a) and calculates the correction amount for the program trajectory so that the shape of r X vessel α
Based on the result of step 7), the control device is controlled so that the actual machining trajectory becomes equal to the desired correction trajectory.
Along with the W pole side r! 'If the I gap is enlarged and overcut occurs, the ear-shaped machining device α411 is used to restrain the ear-shaped square (1) from following a correction trajectory shifted by a predetermined correction amount in the direction of the corner center 7. As a result, overcapture due to the processing integral effect is corrected.

This series of operations has been performed automatically by the operator without creating a program for the correction trajectory.

In addition, in the above embodiment, the Tsukuda control device En, the discriminator (2), the control device α4, the memory (company), the arithmetic unit 110, and the arithmetic unit α
Although we have shown an example in which η is provided independently, it is possible to achieve the same level of performance by using a single control device.Also, in the above embodiment, only the inside corner part 〒 is corrected. We have given an example of how to do this, but by providing a second discriminator that determines whether the target corner is an inside corner or an outside corner, it is possible to perform corrections for both inside corners and outside corners. .

〔Effect of the invention〕

As described above, according to the present invention, there is provided a control means for predicting the change in removal amount at the A ζ corner portion in advance and correcting the change in the W pole side gap due to the change in removal amount, as well as actually controlling the change in the removal amount at the corner portion. By determining when a change in the amount occurs during finishing machining, it is possible to prevent deterioration of machining quality due to changes in the W pole surface area due to changes in the amount of damage that occur at corners, etc. This has the effect of significantly improving machining accuracy at corner portions.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a wire-cut electrical discharge machine according to an embodiment of the present invention, FIG. 2 is a block diagram showing a conventional wire-cut electrical discharge machine, and FIG.
An enlarged view of the fIt pole and the workpiece, Figure 4 is a diagram showing the relationship between the amount of defeat and the lvl gap on the side of the electrode, and Figure 5 is an enlarged view of the wire-like vI pole and the workpiece during inside corner finishing. FIG. 6 is a diagram showing changes in the amount of accommodation at the inside corner, and FIG. 7 is a diagram showing overcut at the inside corner. In the figure fζ, (1) is the wire-shaped electrode, (2) is the workpiece, <3) CX, x9irm, (4) l! Y Su9
A) f-1 (5) (6) C+-bo motor, (7)
(81 is a power amplifier, (9) is a processing power source, aG is a detector, αυ is a control device, @ is a discriminator, α is a control device, (
2) is a memory, and α0α power is a performer.

Claims (2)

[Claims] (1) In a wire-cut electric discharge machine that generates electrical discharge by applying a voltage between opposing wire-shaped electrodes and the workpiece, and also moves the wire-shaped electrode and the workpiece relative to each other to perform processing, the machining position a first discriminator that determines whether the corner portion is moving in an arc or not;
A memory that stores the expected removal amount during straight line machining, a first computing unit that calculates the change in removal amount at the corner section from the information in the memory, and a computer that calculates the change in removal amount at the corner section based on the information in the memory, and The present invention is characterized by being provided with a second arithmetic unit that calculates the amount of correction, and a control device that controls movement of the correction trajectory based on the calculation results of the first and second arithmetic units and the signal of the first discriminator. Wire cut electrical discharge machine. (2) It has a second discriminator that discriminates whether the target corner is an inside corner or an out corner, and the signals from the first and second discriminators described above and the first and second arithmetic units are used. 2. The wire-cut electrical discharge machine according to claim 1, further comprising a control device for controlling movement of the correction trajectory based on the calculation result.