JPS5894925A - Wire electrode for electric discharge machining - Google Patents

Abstract

PURPOSE:To prevent a wire electrode from snapping, by providing a layer of an electroconductive metal of low boiling point on the peripheral suface of a core wire of silicon carbide fibers to keep the strength of the electrode from falling due to heat in electric discharge machining. CONSTITUTION:A layer 2 of an electroconductive metal of low boiling point is provided on the peripheral surface of a core wire 1 of silicon carbide fibers of about 250kg/mm.<2> in tensile strength. A cooling effect is produced by the evaporation of the metal layer 2 to keep the heat resistance from increasing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wire electrode C2 for electrical discharge machining which has less risk of wire breakage during electrical discharge machining.

Wire-cut electrical discharge machining equipment (= in which the workpiece and the wire electrode are moved relative to each other, and the workpiece is machined into any shape by radiation).
Brass wire of about 105cm to α3m is used. By the way, the tensile strength of brass wire is about 40 to 100 (-) at room temperature, but it decreases to about 15 (-) at high temperatures of about 500 degrees Celsius. Therefore, in conventional brass wire wire electrodes, During electrical discharge machining, the heat generated during electrical discharge machining reduces its strength and makes it more likely to break.

The present invention has been made to improve the above-mentioned drawbacks, and its purpose is to prevent the strength of the wire electrode from decreasing due to heat. Examples will be described in detail below.

FIG. 1 is a sectional view of an embodiment of the present invention, which has a structure in which a metal layer 2 made of a low boiling point conductive metal such as brass or zinc is provided around the outer periphery of a core wire 1 made of silicon carbide fiber. This is the result.

The tensile strength of silicon carbide fiber is about 250°C, and even at high temperatures of 1200°C to 1500°C, it has about the same tensile strength.

Therefore, as shown in Figure 2, if the outer circumference 42 of the core wire 1 is provided with a metal layer 2, the heat generated during electrical discharge machining (=
This prevents the strength of the wire electrode from deteriorating. In addition, since the metal layer 2 is made of a low boiling point conductive metal, there is a cooling effect due to vaporization of the metal layer 2, and an increase in thermal resistance can be prevented. It is desirable that the diameter of the wire 1 be approximately 50 to 70 mm larger than the diameter of the wire electrode.

The method for manufacturing the wire electrode shown in Figure 1C2 is as follows:
After applying a metal coating to the core wire 1, the core wire (a method of coating two molten metals, or a method of placing two core wires 1 between two metal plates, and then compacting the metal plates) Possible methods include:

In the embodiment, the core wire 1 is a single fiber, but it goes without saying that a plurality of fibers twisted together may also be used.

As explained above (=, since the present invention provides a metal layer made of a conductive low boiling point metal on the outer periphery of a core wire made of silicon carbide fiber, the heat generated during electrical discharge machining (2) Therefore, the strength of the wire electrode does not deteriorate, and therefore, there is an advantage that breakage of the wire electrode during electrical discharge machining can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the invention. 1 is a core wire made of silicon carbide fiber, 2
is a metal layer. Patent applicant Fujitsu Fanuc Ltd. Agent Patent attorney Gobe Tamamushi (3 others) Figure 1

Claims (1)

[Claims] The outer periphery of the core wire made of silicon carbide fiber (
A wire electrode for electrical discharge machining, characterized in that it is provided with a metal layer made of a biconductive low boiling point metal.