JPH03245919A - Manufacture of electrode wire for wire electric discharge machining - Google Patents

Abstract

PURPOSE:To improve straightness and toughness of an electrode wire and improve automatic bounding performance by continuously applying the bendings 1R-20R to the electrode wire of metal or alloy and heating the electrode wire at a temperature of 200-500 deg.C. CONSTITUTION:Bendings 1R-20R are continuously applied to an electrode wire 1 of metal or alloy by leveller rolls 4. Then, the electrode wire 1 is heated at a temperature of 200-500 deg.C in a furnace 5, to obtain the electrode wire 1 for wire electric discharge machining which wire 1 has superior straightness and toughness and shows superior automatic wire bounding performance.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing an electrode wire for wire electrical discharge machining.
In particular, the present invention relates to a method for manufacturing electrode wires with improved automatic wire connection properties.

[Technology of the Congo Song Dynasty] Wire electrical discharge machining is a process in which an electrical discharge phenomenon is caused between the electrode wire for wire electrical discharge machining and the workpiece, and the workpiece is melted and cut by the heat of the discharge, and is particularly complicated. Suitable for continuous processing of press molds with precise shapes. As such electrode wires for wire electric discharge machining, electrode wires made of copper, brass, molybdenum, tungsten, etc. are generally used.

These electrode wires are required to be processed at high processing speed and with high precision. Regarding processing speed,
The total processing time became an issue, and the wire threading was difficult.
It is required that the wire is difficult to break. Furthermore, with the rapid increase in demand in recent years and advances in wire electrical discharge machines, the number of automatic processing machines that are equipped with an automatic wire connection function and can operate unmanned all night is increasing. Therefore, automatic wire connection has been attracting attention as a characteristic required for electrode wires. The automatic wire connection function is a function that automatically connects the wire when a wire is broken during processing and restores the original processing state, and is especially essential when operating unmanned at night.

In order to perform automatic wire connection smoothly, the electrode wire must be straight and strong. In other words, when passing an electrode wire through a guide die or the like, if the electrode wire is curled or bent, it will not pass smoothly. Further, even if the electrode wire has good straightness, if it is weak, the tip of the electrode wire will get caught on the side wall of the guide die, causing buckling, making connection impossible.

By the way, conventional methods for manufacturing electrode wires include annealing a drawn wire with curls at a low temperature by heating in a running furnace or by current annealing to improve straightness.

[Problems to be Solved by the Invention] However, although straight electrode wires can be obtained with the conventional method described above, the stiffness is insufficient and it is difficult to use the method for automatic wire connection.

The present invention has been made in order to solve the above-mentioned conventional problems, and aims to provide a method for manufacturing an electrode wire for wire electrical discharge machining, which has good straightness and stiffness, and has improved automatic wire connection performance. be.

[Means for Solving the Problems] The present invention provides an electrode wire made of a metal or an alloy with IR to 20R.
This method of manufacturing an electrode wire for wire electrical discharge machining is characterized in that the electrode wire is subjected to continuous bending and then heated at a temperature of 200 to 500°C.

The electrode wire is made of, for example, copper, brass, molybdenum, tungsten, or the like.

The reason why the bending degree R of the electrode wire is limited is that if it is less than 12, the straightness will deteriorate, and if it exceeds 20R, it will not be possible to improve the straightness and stiffness. Further, it is desirable that the electrode wire be bent 5 times or more, more preferably 10 to 20 times. The reason for this is that if the number of bends is less than 5, it becomes difficult to sufficiently improve straightness and stiffness. Note that from the viewpoint of obtaining an electrode wire with good straightness, it is desirable to increase the degree of bending in the initial stage of bending and to decrease the degree of bending in the latter stage.

The reason why the heating temperature is limited is that if the temperature is less than 200°C, improvement in straightness and stiffness cannot be achieved, whereas if it exceeds 500°C, strength will decrease. Note that the heat treatment time is preferably about 0.1 to 10 seconds.

[Function] According to the method of the present invention, it has good straightness and stiffness,
It is possible to manufacture electrode wires for wire electrical discharge machining that exhibit excellent automatic wire connection properties. That is, by continuously repeating bending to a certain degree, the residual stress generated during wire drawing is removed and straightness is improved, while at the same time the yield strength is reduced and the stiffness is improved. In addition, after repeatedly bending, heat treatment is performed at a predetermined temperature where the low-temperature annealing effect appears.
You can further improve your straightness and lower back strength. As a result, it is possible to manufacture an electrode wire for wire electrical discharge machining that has excellent automatic wire connection properties.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Example 1 First, 65/35 brass was wire-drawn to a thickness of 0.2 mm, and then an electrode wire was wound around a feeder. Next, as shown in Fig. 1, the electrode wire 1 is pulled out from the feeder 2, and the leveler
After repeating 2R bending 10 times through a plurality of leveler rolls 4 arranged in
The film was heat-treated for 10 seconds, and then wound up using a winding machine 6.

Examples 2 to 8 7 65/35 brass wire drawn to 0.2 ma+
Each of the electrode wires was subjected to heat treatment while being repeatedly bent using the processing apparatus shown in FIG. 1 under the conditions shown in Table 1 below.

Example 9.10 Two electrode wires drawn from 65/35 brass containing I%All to 0.2ii were bent under the conditions shown in Table 1 below using the processing equipment shown in Fig. 1. Heat treatment was performed while repeating the steps.

Reference Examples 1 to 4 65/35'fL copper wire drawn to 0.21 7
Each of the electrode wires was subjected to heat treatment while being repeatedly bent using the processing apparatus shown in FIG. 1 under the conditions shown in Table 1 below.

Comparative Example 65/35 An electrode wire drawn to a thickness of 0.2 mm was heat-treated at 400° C. for 2°0 seconds.

The obtained electrode wires of Examples 1 to 10, Reference Examples 1 to 4, and Comparative Example were evaluated for straightness, stiffness, and automatic wire connection. The results are also listed in Table 1.

Regarding straightness, as shown in Figure 2, the length from electrode wire 1] 000 mI! Cut off the test wire, hang it vertically with one end supported, and measure the entire length β at this time, (Q /1000) x 100 (%
) was calculated. In this case, the larger the number, the better the straightness. As for the strength of the waist, as shown in Figure 3, after winding the electrode wire l around a mandrel 7 with a diameter of 10 mm while applying a tension of 1 kg with a weight 8, the tension was released and it was left in a free state. The diameter of the circle formed by the electrode 1 wound around the mandrel 7 was determined to be nJ.

In this case, the larger the diameter of the circle, the stronger it is.

As is clear from Table 1 above, the electrode wires of Examples 1 to 10 have good straightness, strong stiffness, and exhibit excellent automatic wire connection properties. On the other hand, in Example 1.2, the heating temperature after repeated bending is out of the range of the present invention (200 to 500°C), and the degree of bending is within the range of the present invention, C1, R.
It can be seen that the electrode wires of Reference Example 3.4, in which the electrode wire deviates from 20R), and Comparative Example, in which bending is not repeated, have insufficient straightness or stiffness, and are inferior in automatic wire connection performance.

[Effects of the Invention] As detailed above, according to the present invention, straightness and stiffness can be improved by continuously repeating bending to a specific degree and then heat-treating at a predetermined temperature at which a low-temperature annealing effect occurs. It is possible to provide a method for manufacturing an electrode wire for wire electrical discharge machining, which has good automatic wire connection properties and is suitable for an automatic processing machine that is equipped with an automatic wire connection function and can be operated unmanned all night.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing the processing equipment used in the examples of the present invention, Fig. 2 is a schematic diagram showing a method for measuring the straightness of an electrode wire, and Fig. 3 is a schematic diagram showing a method for measuring the straightness of an electrode wire. FIG. 2 is a schematic diagram illustrating the method. 1. Electrode wire, 4. Leveler roll, 5. Furnace, 7. Mandrel, 8. Weight.

Claims (1)

[Claims] A method for producing an electrode wire for wire electrical discharge machining, which comprises continuously bending an electrode wire made of a metal or an alloy by 1R to 20R, and then heating the wire at a temperature of 200 to 500°C.