JPS5828428A - Electrical discharge machining unit for wire cut - Google Patents

Abstract

PURPOSE:To detect the residual amount of wire wound round a wire supply reel by applying a voltage between the wire outer periphery wound round said reel and a conductive member pressing said wire outer periphery while contacting with it and assuming the detected voltage to represent said residual amount. CONSTITUTION:A wire 1 is wound such that its first layer is wound traversing along the surface of an insulated processing wire supply reel 2 in the one direction, and then the second layer wound traversing in the opposite direction. A conductive member 3 is contacted with and pressed against the outer peripheral surface 1' of said wire 1. When the number of wound layer of the wire 1 is reduced to only its first layer, and the voltage of a detecting device 5 drops below a prescribed value, the continuity between member 3 and wire 1 is cut off and voltage between terminals 6, 8 becomes zero, enabling it to be detected that the residual wire amount is dropped below a specific value.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wire-cut electrical discharge machine. For more information,
This invention relates to a wire-cut electric discharge machine having a device for detecting the amount of machining wire being saved on the machining wire supply reel.

A wire-cut electrical discharge machine generates electrical discharge in a large volume of insulating fluid with relatively high mass and viscosity, such as water or oil, between the wire as one discharge electrode and the workpiece as the other discharge electrode. Since this is a metal processing machine that utilizes changes in pressure that occur intermittently around the electrical discharge, it is possible to perform processing while maintaining a small gap between the processing wire and the workpiece. Therefore, the wire must be continuously supplied.

Naturally, the processing wire must be under tension. On the other hand, since the processing wire is a consumable item that cannot be reused, it is not practical to fix its end to the processing reel. Further, even if the wire is stuck to the needle 11, the end of the wire is likely to be cut off at the end of processing, which may cause an unexpected accident.

Therefore, in conventional wire-cut electric discharge machines, the winding start point of the machining wire on the reel is set at the free end, and the decrease in the wire is detected using a microphone switch and the machining operation is started. It was supposed to be terminated. However, since the wire winding start point is the free end, the end of the wire detaches from the reel and loses tension, resulting in irregular running while shorting with the workpiece, increasing the width of the machining groove irregularly and machining. The drawback is that accuracy is extremely likely to be impaired.

The purpose of the present invention is to eliminate this drawback.

It is proposed to provide a wire-cut electric discharge machine having a device for detecting the remaining amount of machining wire wound on a reel for supplying machining wire.

The gist is: B) A wide reel is used as the wire supply reel for processing, and the wire traverses the reel surface in one direction to wind the first layer, and then in the opposite direction. The reel is wound in two layers, and the reel is unwound in the reverse order, and this reel is electrically insulated from the processing wire. A conductive support member is provided on the outer periphery of the wire attached to the reel *1 and is in contact with the outer periphery of the wire and presses the outer periphery of the wire with a specific pressure. (c) The above processing wire and the above A voltage is applied to the electrically conductive member that contacts and presses the outer circumference of the wire (optional) until the wire is sufficiently weighed out. If it is attached, the koshiki will be O above.
The connection between the processing wire and the above-mentioned conductive member has electrical conductivity, but if the amount of wire wound around the reel decreases below a certain value, the wire still maintains sufficient tension. The remaining amount is detected and the mK machining can be stopped when the preferable machining state described above occurs.

However, in order to apply tension to the processing wire, it is necessary for K to apply a reverse torque to the reel in some form, but it is possible to use the above-mentioned conductive member for this purpose, and it is also possible to Since a processing voltage is applied between the wire and the workpiece, it is possible to use a part of this voltage as a voltage for detecting the remaining amount of wire.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A remaining wire amount detection device for a wire-cut electrical discharge machine according to an embodiment of the present invention will be described below with reference to one drawing, and the configuration and unique effects of the present invention will be clearly explained.

FIG. 1 is a conceptual structural diagram (elevation view) of the remaining wire amount detection device. Kj1-tl is processing wire),
It is hooked onto an insulating reel 2 and is rewound one after another. Reference numeral 3 designates a conductive member which is attached to the reel 2 and pressed into contact with the outer circumferential surface 1' of the nine wire 1, making sliding contact or rolling contact as desired. An elastic member for suppressing the conductive member 3 of the fourth company against the outer circumferential surface 1'K of the wire 1 is shown, but the method of this suppression is completely free. 5 is In
69-i is a device for applying a voltage for detecting the remaining amount of wire IK wire running downward at the terminal 69-i. What is shown in the figure is just an example of this structure and does not have any limiting meaning. F is a lead wire connected to the conductive member 3, and 8 is a terminal thereof. A voltage for detecting the amount of remaining wire in slK is applied to terminal e.

FIG. 2 is a conceptual plan view showing a state in which the amount of remaining wires is below a specific value in the remaining wire amount detection device. Since the processing wire 1 is wound on the reel 2 so as to form two-dimensional layers, if the number of wound layers of the processing wire is only the first layer and the value is below a certain value as shown in the figure, Since the conduction between the conductive member 3 and the wire 1 is broken and the voltage between the terminals 6 and 8 becomes zero (0), it is possible to detect that the amount of remaining wire has fallen below a specific value.

As mentioned above, the contact between the conductive member 3 and the outer circumferential surface 1' of the processing wire 1 wound around the reel 2 may be a sliding contact or a rolling contact, but it is preferable that Since it is necessary to apply reverse torque to the reel 2 in order to apply IK tension, it is possible to use both of these functions.

In addition, applying the voltage for detecting the remaining amount of wire to the wire 1, which is a movable body, requires a slip ring, so it is somewhat cautious, so a part of the processing voltage is divided and used as the detection voltage. It is also quite possible.

As explained above, according to the present invention, in a wire-cut electrical discharge machine, the reel for supplying machining wire has four parts. !
A wire-cut electric discharge machine having a simple device for detecting the amount of wire attached and remaining can be provided.

[Brief explanation of the drawing]

FIG. 1 shows a conceptual structure a of a remaining wire amount detection device used in a wire-cut electric discharge machine according to an embodiment of the present invention.
ll (elevation view), and FIG. 2 is a conceptual plan view of the above device in a state where the amount of remaining wire is below the special electric value. 1φ...Wire for processing, 1'...-Outer peripheral surface of the wire for processing, =...Reel for supplying wire, 3...Conductive member pressed in contact with the outer periphery of the wire, 4...Elastic member , 5.--A device for applying a voltage for detecting the remaining amount of wire to the wire, 6.-Terminal for applying a voltage for detecting the remaining amount of wire to the e-wire,

Claims (1)

[Claims] In the wire-cut electrical discharge machine, the wire supply reel for application 1 has a structure in which the processing wire is traversed and returned to the reel support shaft 19, and is insulated from the processing wire. ), (b) on the reel *
*A conductive member is pressed in contact with the outer periphery of the attached wire, and a voltage is applied between the wire and the conductive member, and (b) the wire and the A device is provided for detecting the presence or absence of electrical continuity between the wire and the conductive member to detect the remaining amount of the wire wound on the reel. Wire cut electrical discharge machine.