JPH05285736A - Wire electrode cutting device in wire electric discharge machine - Google Patents

Abstract

PURPOSE:To lengthen the lives of feed elements, and thereby enhance reliability by letting a wire electrode be surely brought into contact therewith between the respective feed elements at the upper and lower sections when the wire electrode is charged with electricity so as to be fused due to heating in a wire electric discharge machine. CONSTITUTION:Respective feed elements 14 and 15 at the upper and lower sections of a wire electrode cutting section 13 are constituted to be capable of being moved back and forth, and a contact detecting circuit 51 is interposed between the wire electrode 1 and each feed element 14 and 15 to detect contact, so that current is constituted to flow depending on the thickness and kind of the wire electrode 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire electrode cutting device of a wire electric discharge machine which blows a current through a wire electrode to melt the wire electrode.

[0002]

2. Description of the Related Art FIG. 4 is a schematic view showing an example of a wire electrode cutting portion of a conventional wire electric discharge machine. In the figure, 1 is a wire electrode, which is sent out in the arrow direction by a wire feed roller 11 driven by a motor 12. Reference numeral 13 denotes a cutting portion of the wire electrode 1, which is provided with an upper power supply electron 14 and a lower power supply electron 15 arranged near the wire electrode 1 and a cutting circuit 8 for controlling a cutting current. 17 is a wire electrode 1
The cutting roller is connected to the motor 18, and the torque of the motor 18 is controlled by the control circuit 19.
20 is a pressing roller for the wire electrode 1 which is a pneumatic cylinder 21
And is moved in the direction of arrow a or b by introducing air pressure from the air pressure source 22 or 23. Reference numeral 24 is a guide nozzle provided below the cutting roller 17 and is provided with a power feeding die 25 into which the wire electrode 1 is inserted.

Next, the operation will be described. To cut the wire electrode 1 after processing the work piece, first, air pressure is introduced from the air pressure source 22 into the pneumatic cylinder 21 to advance the piston, and the pressing roller 20 connected thereto is moved in the direction of arrow a. Let As a result, the wire electrode 1 comes into contact with the upper power supply 14 and the lower power supply 15, and is sandwiched between the pressing roller 20 and the cutting roller 17.

On the other hand, the wire electrode 1 recognizes the thickness and type, and is cut by the known wire electrode cutting method disclosed in, for example, Japanese Patent Laid-Open No. 1-252318.

[0005]

Since the conventional wire electric discharge machining apparatus is constructed as described above, when the wire electrode 1 is cut, the upper and lower power supply terminals of the cutting circuit portion may be inclined due to aging. is there. Similarly, the moving position of the pressing roller may change due to aging. When the above occurs, the wire electrode 1 and the upper and lower power supply terminals 14 and 15 are separated from each other when the wire electrode 1 is cut, and the contact becomes unstable. Therefore, the wire electrode 1 may not be cut, and depending on the contact state, a discharge may occur between the wire electrode 1 and each of the upper and lower power supply terminals 14 and 15, and the power supply electrode may be damaged.

The present invention has been made in order to solve the above problems, and it is possible to surely make a contact between the wire electrode of the cutting circuit portion and each of the upper and lower power supply terminals to reliably cut the wire electrode. An object of the present invention is to obtain a wire electrode cutting device for a wire electric discharge machine that can be used.

[0007]

DISCLOSURE OF THE INVENTION A wire electric discharge machine according to the present invention is designed to solve the above problems and achieve the object, and in order to cut the wire electrode, tension is applied to the wire electrode. A means for supplying a current to the wire electrode for heating the electrode, and a control means for instructing the tension applying means and the current supplying means to the optimum values of the tension and the cutting current corresponding to the thickness and type of the wire electrode. And the contact between the wire electrode and each of the upper and lower power supply terminals is ensured, and the above-mentioned contact current is detected to flow the above-mentioned cutting current.

[0008]

In the present invention, the tension applying means, the contact detecting means, and the current supplying means apply the optimum tension to the wire electrode in accordance with the thickness and the kind of the wire electrode according to the command from the control means, and perform the optimum heating. Then, the wire electrode is blown.

[0009]

【Example】

Example 1. FIG. 1 is a block diagram schematically showing an embodiment of the present invention. In the figure, 51 is a contact detection circuit that detects contact between the wire electrode 1 and the upper power supply 14 and the lower power supply 15 when the wire electrode 1 is cut, and 52 is moved in the direction of arrow a to bring the cutting part 13 into contact with the wire electrode 1. Since the other parts of the disconnecting section drive circuit are the same as those of FIG. 4 described as the related art, description thereof will be omitted.

FIG. 2 is a schematic diagram of the cutting drive circuit 52 of the cutting unit 13. 53 is a drive motor, 54 is a gear, and 55 is a ball screw. The cutting portion 13 is connected to the ball screw 55 and operates in the directions of arrows a and b by driving (rotating direction) of the motor 53. The disconnection drive circuit 52 is NC
It is driven by a command from the device 50.

FIG. 3 is a schematic diagram of the contact detection circuit 51. 56 is a current limiting resistor, 57 is a diode, 58 is a photocoupler, and 59 is a power supply. When the wire electrode 1 comes into contact with the upper power supply 14 and the lower power supply 15, a power source 59
+ Of photo coupler 58, diode 57, resistor 56
Via upper power supply 14, wire electrode 1, lower power supply 1
5, a closed circuit of the power supply 59 is formed. Therefore, a signal is sent from the photo coupler 58 to the NC device 50.

The present invention is constructed as described above, and its operation will be described below. In order to cut the wire electrode 1 after processing the work piece, first, air pressure is introduced from the air pressure source 22 into the pneumatic cylinder 21 to advance the piston, and the pressing roller 20 connected thereto is moved in the direction of arrow a. To move. The wire electrode 1 is given an appropriate tension by the tension control circuit 19.

Next, the cutting section 13 moves in the direction of arrow a by the cutting section drive circuit 52. In that case, the wire electrode 1, the upper power supply electron 14, and the lower power supply electron 15 detect contact by the contact detection circuit 51, and the signal thereof is output. Are sent to the NC device 50. The disconnection part drive circuit 52 from the NC device 50 is sent by the signal sent.
Stop signal is sent to the. When the cutting portion 13 is tilted, as shown in FIG. 2C, the connection portion of the cutting portion 13 and the ball screw 55 from the drive circuit 52 is in an elongated hole state so as to be movable. Since 1 is under tension, upper power supply 14 and lower power supply 15
Moves forward and backward, and each of the power supply terminals 14 and 15 surely contacts the wire electrode 1. The wire electrode 1 detects a contact by a contact detection circuit 51 between the upper power supply 14 and the lower power supply 15. The pressing roller 20 and the cutting roller 17 are in contact with each other.
Sandwiched between. After that, an optimum cutting current flows by the cutting current circuit 8, and the wire electrode 1 is cut. After cutting, the cutting unit drive circuit 52 moves the cutting unit 13 in the direction of arrow b. Next, a series of operations are performed in which air pressure is introduced from the air pressure source 23 into the air pressure cylinder 21 to move the piston backward, and the pressing roller 20 connected thereto is moved in the direction of arrow b.

[0014]

As is apparent from the above description, according to the present invention, when the wire electrode is cut, it is possible to reliably make contact between the wire electrode and each of the upper and lower power supply terminals and detect the contact. After that, by supplying a cutting current, it is possible to surely cut the wire electrode, the upper and lower power supply terminals are not damaged, and reliability is improved and the maintenance period can be extended.

[Brief description of drawings]

FIG. 1 is a configuration diagram schematically showing an embodiment of the present invention.

FIG. 2 is a diagram showing an example of an implementation circuit of drive circuit means for a cutting section that constitutes a main part of the present invention.

FIG. 3 is a diagram showing an example of an implementation circuit of a contact detection unit between the wire electrode and the upper and lower power supply terminals that form the waist of the present invention.

FIG. 4 is a configuration diagram schematically showing a conventional wire electrode cutting device.

[Explanation of symbols]

 1 Wire Electrode 8 Cutting Current Control Circuit 11 Wire Electrode Feeding Pulley 13 Cutting Section 14 Upper Feeder 15 Lower Feeder 17 Cutting Roller 18 Motor 20 Holding Roller 21 Pneumatic Cylinder 25 Feeding Die 50 NC Device 51 Contact Detection Circuit 52 Cutting Section Drive Circuit

Claims (1)

[Claims] 1. A wire electric discharge machine for causing a wire electrode to face a work piece with a minute gap therebetween and cutting the work piece by discharge energy, and a tension applying means for applying a tension to the wire electrode, and the wire. A wire electrode cutting device for a wire electric discharge machine, comprising current supply means for supplying a current to an electrode, wherein upper and lower feeding parts of a cutting part for cutting a wire electrode are movable.