JPH0542420A - Electrifying device for wire-cut electric discharge machine - Google Patents

Abstract

PURPOSE:To electrify a wire electrode immediately close to a machined part, to improve machining accuracy and machining speed and to enable electric discharge machining for a long time with high efficiency. CONSTITUTION:An electrifying bar 3 which is pressed into contact with a wire electrode 2 is provided at a guide 1 part provided on both sides of a workpiece. Electrifying bar feeding devices 4, 5 and 6 are provided for moving the electrifying bar 3 in the direction orthogonal to the pressing direction and for changing a contact position with the wire electrode 2. Due to this, as the wire electrode 2 is electrified in the shortest distance to a part to be machined and electric energy loss is reduced so as to prevent disconnection caused by heating of the wire electrode 2, large electric current can be supplied efficiently and machining with high accuracy can be carried out at high speed and high efficiency. Also, by changing the contact position with the wire electrode 2 and correcting abrasion of the contact part, stable machining is enabled for a long time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current-carrying device in a wire-cut electric discharge machine.

[0002]

2. Description of the Related Art In wire-cut electric discharge machining in which a workpiece is cut, cut out, and punched by electric discharge machining using a wire electrode, a moving and traveling wire electrode is accurately and stably guided linearly in a machining portion. In addition, it is extremely important to stably energize the moving wire electrode without distorting the machining pulse energy without loss and for improving the machining accuracy and machining speed of the wire cut.

Conventionally, the wire guide is arranged near both sides of the work piece so as to reduce the deflection of the electrode as much as possible and to provide a stable guide. On the other hand, the wire electrode is energized by conduction, and is provided so as to come into contact with the wire electrode at a position apart from the guide.
Therefore, the wire electrode from the contact position of the conduction electrons to the processed portion facing the workpiece is inevitably long. Since a pulse current with a large current density flows through this thin and long wire electrode, the energy loss electrically becomes extremely large, the rise and fall of the pulse current is delayed due to the increase of the inductance, and the discharge performance deteriorates. Since a large current flows through the thin wire and it is heated, it is easy to cause a wire breakage accident.

[0004]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, the present invention energizes the wire electrode in the vicinity of the portion to be machined facing the workpiece, thereby improving machining accuracy and machining speed. The purpose is to enable high-efficiency electrical discharge machining without disconnection.

[0005]

In order to achieve the above object, the present invention is directed to a wire electrode and a work piece to be processed while the wire electrode continuously supplied is moved between guides provided on both sides of the work piece. In a current-carrying device of a wire-cut electric discharge machine for performing electric discharge machining by performing pulsed current between the bodies, a current-carrying bar for press-contacting the wire electrode is provided in the guide portion, and the current-carrying bar is moved in a direction orthogonal to the pressure-contacting direction. It is characterized in that an energizing bar feeder for changing the contact position with the wire electrode is provided.

[0006]

As described above, according to the present invention, the current-carrying bar which is in pressure contact with the wire electrode is provided at the guide portions located on both sides of the workpiece, and the current-carrying bar is moved in the direction orthogonal to the pressure welding direction. Since it is equipped with a current-carrying bar feeder that changes the contact position with the wire electrode, the wire electrode can be energized in the shortest distance to the machining part, and there is less loss of machining energy electrically. Since the wire breakage due to heating is also eliminated, a high-current machining energy can be efficiently supplied, which enables highly accurate machining at high speed and high efficiency.

Further, since the current-carrying bar is moved in the direction orthogonal to the pressure contact direction to change the contact position with the wire electrode, it is possible to perform stable machining for a long time while correcting wear of the contact portion. it can.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment of the drawings.
It In FIG. 1, reference numeral 1 is a V-groove guide, which is an abrasion resistant guide surface.
Carbide material 11 such as diamond and sapphire is used to ensure wear resistance.
They are laminated, and the wire electrode 2 is slidingly guided there.
3 is the wire electrode 2 pressed against the guide surface from the side opposite to the guide
Use a good conductor current bar to move in the direction orthogonal to the pressure welding direction.
It can be moved to change the contact position with the wire electrode 2.
It That is, the energizing bar 3 has its base end fixed by the chuck 4.
Supported. The chuck 4 itself is ZrO₂, Y ₂O₃Two
mol% material or Si₃N_FourMade of insulating material, such as
The surface crimping plate 41 is made of a conductive material, and the conductive lead wire 42
Connect. In addition, the back surface of the current-carrying bar 3 is an insulating roller.
Press with 5. 6 is a cylinder for moving the chuck 4,
A drive device such as a motor, 7 is a system for controlling the position of the guide 1.
It is a drive device such as a binder or a motor.

As the current-carrying bar 3, WC type, TiC
System, HfC system, B ₄ C system, TiB ₂ system, etc. Conductive hard particles, made of a good conductor mixed with fibers, whiskers, etc. Further, if necessary, super hard particles such as cBN, DIA, etc. are mixed. It is a long plate-shaped material made of a good conductor with improved wear resistance. The wire electrode 2 is guided by being sandwiched between the current-carrying bar 3 and the guide 1, and is used for processing while slowly moving and running in a direction perpendicular to the paper surface. Is 100 by cylinder 7
g ~ 5 kg, for example 3 for wire electrode with wire diameter 0.2 mmφ
Add about 00g and guide. With this pressure guide, the wire electrode 2 is stretched linearly at a fixed position without vibrating, and stable guide is performed.

On the other hand, the cylinder 6 for controlling the position of the energizing bar 3 may also have a driving force of about 1 to 5 kg, and is generally about the same.
By moving at a speed of about 0.01 to 0.5 mm / h, it is possible to always carry out stable contact energization without being affected by the abrasion of the energizing bar 3. Although the control device for the cylinder 6 is not shown, the consumption of the current-carrying bar 3 is proportional to the moving amount of the wire electrode 3, that is, the moving speed, and the moving speed of the wire electrode 1 corresponds to the machining current supplied from the crimping plate 41 through the wire electrode 2. Since the control is performed in proportion, the control unit of the cylinder 6 may move and feed the cylinder 6 by controlling the machining current AH as a signal.

By this control feeding, the current-carrying bar 3 comes into contact with the wire electrode 2 on a new surface at all times, so that stable current-carrying can be performed while keeping the contact current-carrying resistance and the contact pressure constant. The length of the energizing bar 3 is usually 50 ~
About 100 mm is used, and the service life in that case is 15
Since it is 0 to 1500 hours, stable processing can be performed for a long time.

As described above, the wire bar 2 can be stably energized by moving and feeding the energization bar 3, and the wire electrode 2 is energized at the position of the guide 1 so that the workpiece and the wire electrode face each other. Since the current is applied in the position closest to the processing part, stable current can be achieved without loss of processing current and distortion, and the wire electrode heating and disconnection due to large current can be avoided and stable for a long time. It is possible to continue the electrical discharge machining. Further, since the L of the energizing circuit becomes small, the pulse current peak value Ip can be made large, and high-frequency, high-efficiency wire-cut electric discharge machining can be performed by performing high-frequency pulse discharge with a sharp rise and fall of pulse discharge. You can

[0013]

As described above, according to the present invention, a current-carrying bar for press-contacting a wire electrode is provided at guide portions located on both sides of a work piece, and the current-carrying bar is moved in a direction orthogonal to the press-contacting direction. Since it is equipped with an energizing bar feeder that changes the contact position with the electrode, the wire electrode can be energized in the shortest distance to the machining part, reducing the electrical processing energy loss and reducing the wire Since it is possible to prevent disconnection accidents due to heating of the electrodes, it is possible to efficiently supply a large amount of machining energy, which enables highly accurate machining at high speed and efficiently.

Further, an energizing bar feeding device for moving the energizing bar in a direction orthogonal to the pressure contact direction is provided, and energizing is performed while changing the contact position with the wire electrode, and stable energization is performed while correcting wear of the contact portion. Therefore, there is an effect that the life of the energizing bar can be remarkably extended.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of a current carrying device according to the present invention.

[Explanation of symbols]

 1 Guide 2 Wire electrode 3 Energizing bar 4 Chuck 5 Roller 6, 7 Drive device

Claims (1)

[Claims] 1. Electric discharge machining is performed by pulse-energizing between a wire electrode and a workpiece while moving and moving continuously supplied wire electrodes (2) between guides (1) provided on both sides of the workpiece. In the current-carrying device of the wire-cut electric discharge machine, the current-carrying bar (3) for pressing the wire electrode (2) to the guide (1) is provided, and the current-carrying bar is moved in the direction orthogonal to the pressure-welding direction. The above-mentioned current-carrying device, which is provided with current-carrying bar feeders (4,5, 6) for changing the contact position with the electrode (2).