JPH02279223A - Automatic supply control device for wire of wire electric discharge machining equipment - Google Patents

Abstract

PURPOSE:To shorten the amount of a wire electrode drawn out due to a supply failure to the maximum extent by providing control means for operating the re-supply of a wire electrode to an electric discharge machining portion in response to that the let-off length of a wire electrode detected by a rotation detecting device is larger than a preset designated let-off length. CONSTITUTION:In response that the let-off length of a wire electrode 1 detected by a rotation detecting device 3 for detecting the let-off length of the wire electrode 1, which is disposed in a wire running system, is above a preset desig nated let-off length, the wire electrode 1 is controlled to be re-supplied to an electric discharge machining portion by control means 10. Thus, the amount of the wire electrode 1 drawn out due to a supply failure is reduced to the minimum, and the length of waste wire electrode can be minimized, so that a trouble of waste wire disposal can be decreased and a time loss can be shortened to the minimum.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a wire automatic discharge machine in which electric discharge is generated between a traveling wire electrode and a workpiece, and the workpiece is machined by electric discharge energy. Supply system? II
'About J direct.

[Conventional technology]

Generally, the current state of wire electric discharge machines is to machine a workpiece using a portion in which the wire electrode runs in a vertical direction, in other words, in an up-down direction. The wire electrode is guided by various rollers of a wire traveling system of an automatic wire feeding device attached to a wire electrical discharge machine and is fed to a wire head having a wire guide. On the other hand, the table on which the workpiece is attached moves in the X-axis direction and Y-axis direction according to the machining status of the workpiece according to the command from the NC device, and the table moves in the servo direction between it and the wire electrode supplied to the wire head. By repeating the function, the workpiece is electrically discharged into a predetermined shape.

Conventionally, in a wire electrical discharge machine, the method of checking the wire electrode feeding length is to use a timer built into the wire automatic feeding device to control the wire electrode feeding time and detect the feeding length. There is a way. The wire electrode is sent out to the electrical discharge machining site in rapid traverse through an encoder roller and a delivery roller arranged in the wire electrode running system, and then the delivery speed of the wire electrode is slowed down to allow the wire electrode to start working on the workpiece. When the wire electrode is successfully fed through a narrow hole such as a hole to a pull-out roller provided downstream of the workpiece, the wire electrode is then set to the electrical discharge machining speed. When controlling the wire electrode feeding length with a timer, the timer is set to a predetermined feeding time in order to send the wire electrode to the electrical discharge machining site by a predetermined feeding length. Currently, the sending time of the timer is set to include loss times such as slips between the encoder roller and the wire electrode and slips between the sending roller and the wire electrode in the N-pole running system.

[Problem to be solved by the invention]

However, in the automatic wire feeding device of a wire electrical discharge machine, the method of detecting the feeding length of the wire electrode to the electrical discharge machining area by using a timer has a problem in that the slip that occurs when feeding the wire electrode cannot be detected as described above. Loss time must be included, and if the wire electrode is successfully fed to the electrical discharge machining area, such as the start hole of the workpiece,
There is not much of a problem, but if the wire electrode fails because it cannot pass through the narrow size of the workpiece, it will take too much time to try again. A phenomenon occurs in which the feeding length of the wire electrode is too long, and the wire electrode that is fed out becomes too long, that is, the length of the waste wire of the wire electrode becomes extremely long. There is a problem that processing becomes extremely difficult. In addition, there are various heights of workpieces installed on the work table, and when changing the workpiece to a different height, the timer setting time must be changed one by one, or the set time must be changed to a fixed time. If the wire electrode is sent out in this manner, there is a problem in that a time loss occurs.

The purpose of this invention is to solve the above problems,
Using an encoder roller placed in the wire electrode running system of the automatic wire feeding device, the length of the wire electrode being sent out is detected through the rotation of the encoder roller, and a detection signal that is longer than the preset feeding length is responded to. Then, try again to feed the wire electrode into the small hole such as the start hole of the workpiece, reduce the time to try feeding the wire electrode to the minimum, and continue (immediately and smoothly in the machining process of wire electric discharge machining). Wire in a wire electrical discharge machine that can be controlled so that it can be moved, and also shorten the length of the waste wire electrode to the minimum, saving wire electrodes and simplifying the disposal of waste wire electrodes. An object of the present invention is to provide an automatic feeding control device.

(Means for Solving the Problems) In order to achieve the above object, the present invention is configured as follows.That is, the present invention applies a voltage between the wire electrode and the workpiece. In a wire electrical discharge machine that electrically discharges a workpiece by electrical discharge machining, a rotation detection device that detects the length of a wire electrode provided in a wire running system that supplies the wire electrode from a source bobbin to an electrical discharge machining site; A wire electrical discharge machine comprising: control means for re-feeding the wire electrode to the electrical discharge machining area in response to the wire electrode delivery length detected by the device being equal to or greater than a preset predetermined delivery length; This invention relates to an automatic wire supply control device.

[Effect]

The automatic wire feeding control device according to the present invention is constructed as shown in letter L and operates as follows.

In other words, this automatic wire feeding control device detects when the feeding length of the wire electrode detected by the rotation detection device installed in the wire running system for detecting the feeding length of the wire electrode is equal to or larger than a predetermined feeding length. ft! to re-feed the wire electrode to the electrical discharge machining site in response to a certain event. I control, the amount of wire electrodes that are fed out due to supply failure is extremely reduced, the length of waste wire electrodes is minimized, troubles in waste wire disposal are reduced, and time loss can be shortened to a minimum. .

(Embodiment) An embodiment of the automatic wire supply control device according to the present invention will be described below with reference to the drawings. Fig. 1 shows the wire electrodes of a wire electrical discharge machine that can achieve the automatic wire supply control device according to the present invention. FIG. 2 is a schematic perspective view showing a part of the running system, FIG. 2 is an explanatory diagram for hanging the wire electrode on the encoder roller of FIG. 1, and FIG.・It is a Tsuku diagram.

This wire electric discharge machine applies electric voltage between the wire electrode l and the workpiece to perform electric discharge machining on the workpiece.
In general, a cross slide that can set up a workpiece and move horizontally moves in the X-axis direction and Y-axis direction according to the machining status of the workpiece according to commands from the NG device, and the cross slide that can move the workpiece in the horizontal direction The servo movement between the electrode 1 and the electrode 1 is repeated by a servo feed mechanism driven by a servo motor, and the workpiece is electrically discharge-machined into a predetermined machining shape by a relative movement that is a combination of both movements. In addition, the automatic wire feeding device built into the wire electrical discharge machine is equipped with various rollers such as a tension roller, a direction change roller, a felt brake roller, and a delivery roller in order to guide the wire electrode 1 and feed it to the electrical discharge machining area. It has a wire electrode running system consisting of: In this wire electrode running system, the wire electrode sent out from the source bobbin on which various wire electrodes 1 are rolled up passes through a plurality of direction changing rollers, a tension roller and a felt brake roller. , a delivery roller, etc., to the electrical discharge machining area of the workpiece, and then, via a pull-out roller, to a take-up roller or a waste tear reservoir.

In FIG. 1, a part of a wire electrode running system in an automatic wire feeding device is shown. In this wire electrode running system, a feed roller 5 and an encoder roller 2 disposed upstream of the feed roller 5 are attached to a head (not shown) of a wire electric discharge machine. An encoder 3 functioning as a rotation detection device is attached to the encoder roller 2. Normally, the encoder roller 2 rotates in both forward and reverse directions. Therefore, a one-way clutch 4 is provided for the encoder roller 2 so that the forward rotation for feeding the wire electrode 1 is outputted to the encoder 3 as an effective signal. In addition, wire electrode 1
In order to minimize the slip occurring between the encoder roller 2 and the encoder roller 2, as shown in FIG.
is wound around the encoder roller 2 for one and a half turns. As a result, the frictional resistance between the wire electrode 1 and the encoder roller 2 becomes large, there is no slippage between them, and the traveling distance of the wire electrode 1 becomes the accurate rotational speed of the encoder roller 2, which is detected by the encoder 3. .

The automatic wire supply control device according to the present invention detects the feeding length of the wire electrode 1 by using the encoder roller 2 in the wire pole traveling system, and detects the feeding length of the wire electrode 1.
An electric signal indicating the delivery length is input to the controller 10, and the wire electrode supply is retried in response to the detected length.

The rotation speed of the encoder roller 2 is converted into an electrical signal by the encoder 3 into a pulse waveform, and the acid pulse waveform is input to the pulse shaper 6 of the controller 10. The pulse waveform of the encoder 2 input to the pulse shaper 6 is shaped by the pulse shaper 6 and input to the pulse calculator 7 . The pulse calculator 7 calculates the number of input pulses, and the calculated number of input pulses is input to the comparator 8 as a signal indicating the rotation speed of the encoder roller 2. This comparator 8 contains a pulse setting device 9 that stores a predetermined rotation signal set in advance.
The predetermined rotation signal is inputted from the comparator 8, and the predetermined rotation signal is compared with the rotation signal input from the pulse calculator 7. Comparison signals of these rotation signals are manually input to the CPUI 1. Therefore, CPU1. 1, if it is determined based on the comparison signal from the comparator 8 that the number of rotations detected by the encoder 3 is larger than a predetermined number of rotations, the fine details such as the start hole of the workpiece of the wire electrode 1 are Set to retry the supply even if the supply to the hole has failed.

Further, if the length is shorter than the predetermined length, it means that the wire electrode 1 has been successfully inserted into the small hole of the workpiece, and the electric discharge machining process is then continued according to the conventional wire electric discharge machining process.

Next, we will briefly explain an example of the retry operation process for supplying the wire electrode 1 to a small hole such as a start hole of a workpiece. When the comparator 8 in the controller 10 compares the pulse electric signal with the electric signal of the predetermined length of wire electrode 1 and CPU II detects that the wire electrode 1 is longer than the predetermined length, CPtJll in the controller 10 A signal is sent to the automatic wire feeding device, and the automatic wire feeding device temporarily stops feeding out the wire electrode 1. Next, the automatic wire feeding device receives a command from the controller 10, cuts the wire electrode I at a predetermined location, winds up the waste wire electrode with a pull-out roller, and raises the holder of the feeding pipe to remove the wire electrode 1. The wire electrode l is fed out for a predetermined length and then stopped.Then, the wire electrode l is held between an annealing roller and a common roller,
Ti is passed through the wire electrode 1 and the wire is annealed. Cut the tip of the wire electrode 1 to a small length with a cutter, lower the supply pipe holder, and
The annealing roller and common roller that were holding the wire were released, and the wire was fed out and an attempt was made to insert it into a small hole such as a start hole or a processing hole formed in the workpiece.

When the wire electrode 1 is successfully inserted into the small hole, the wire electrode 1 is held between the pull-out rollers and the supply of the wire electrode 1 is completed.6 Next, the operation is performed according to the normal wire electric discharge machining process.

The automatic wire feeding control device according to the present invention is configured as described above as an embodiment, but is not limited to the above embodiment. It can also be converted to feed rate and displayed. In that case, the feed rate can be fed back to the controller to control the feed rate of the wire and electrode. Further, the feeding speed of the wire electrode can be fed back to the controller of the automatic wire feeding control device to control the wire feeding speed. This control system is particularly effective when the wire electrode is a thin wire.

〔Effect of the invention〕

The automatic wire feeding control device according to the present invention is constructed as described above and has the following effects. That is, this automatic wire supply control device is used in a wire electrical discharge machine that applies voltage between the poles of a wire electrode and a workpiece to perform electrical discharge machining on the workpiece. A rotation detection device that detects the length of the wire electrode provided in the running system, and a rotation detection device that responds when the length of the wire electrode detected by the rotation detection device is equal to or larger than a predetermined length of the wire electrode. and a control means for re-feeding the wire electrode to the electrical discharge machining site, so that when receiving an electrical signal from the rotation detection device indicating that the wire electrode delivery length is equal to or longer than a preset predetermined delivery length, , immediately stop feeding the wire electrode, and cut the wire electrode with a cutter. The cut-off stray wire is pulled out and wound into a row, and the tip of the wire electrode is annealed to straighten the wire electrode itself.
The wire guide leads to the start hole of the workpiece and the operation takes place. Therefore, the amount of wire electrodes that are fed out due to feeding failure can be extremely shortened, the length of the waste wire electrodes can be kept to a minimum, and since the wire electrodes are short, the wire electrodes can be easily disposed of. This reduces troubles and reduces time loss to a minimum. Moreover,
Since there is less wire electrode loss, the cost of the wire electrodes used can be reduced, and the machining process in the wire electric discharge machine can be significantly improved.

[Brief explanation of drawings]

Fig. 1 is a schematic perspective view showing a part of the wire electrode running system of a wire electric discharge machine, Fig. 2 is an explanatory diagram for hanging the wire electrode on the encoder roller of Fig. 1, and Fig. 3 is a diagram according to the present invention. It is a block diagram showing the processing system of the wire automatic supply side f111 device. ■---Wire electrode, 2-11-~-1 encoder roller, 3--Encoder, 4--One-way clutch, 5--Feeding roller, 6------Pulse shaping device, 7--pulse calculator, 8----- comparator, 9
------Pulse setting device, 10--Controller,
11---.-CPU.

Claims (1)

[Claims] In a wire electrical discharge machine that applies a voltage between the wire electrode and the workpiece to electrically discharge the workpiece, the wire electrode is fed from the wire running system that supplies the wire electrode from the source bobbin to the electrical discharge machining area. A rotation detection device that detects the length, and a wire electrode re-supplied to the electrical discharge machining area in response to the wire electrode feeding length detected by the rotation detection device being equal to or greater than a predetermined feeding length. An automatic wire feed control device for a wire electrical discharge machine, comprising: a control means for operating the wire;