Electrical discharge machining method

Abstract

To provide an electrical discharge machining method that can improve machining efficiency by minimizing the volume directly removed by electrical discharge without reducing machining conditions. Furthermore, to ensure that the hollow electrode has sufficient rigidity against heat input from the side of the electrode. [Solution] The electrical discharge machining method uses a hollow electrode 11 that has the contour of the desired machining shape and a reinforcing portion 12 connecting two points on the contour to cut out a shape from a metal material 21.

Description

Technical Field

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[0001] The present invention relates to an electrical discharge machining method.

Background Art

[0002] Citation Document 1 describes that one of a plurality of electrodes for electrical discharge machining made from a conductive metal formed body by thermal spraying is detachably attached to a reinforcing body in a concave-convex fitting relationship with each electrode to form an electrode assembly.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when performing electrical discharge machining using the electrode of Citation Document 1, there is a problem that the machining efficiency is low and the machining time becomes long.

Means for Solving the Problems

[0005] An electrical discharge machining method according to an embodiment uses a hollow electrode having a contour of a target machining shape and having a reinforcing portion connecting two points on the contour.

Effects of the Invention

[0006] According to the electrical discharge machining method of the present disclosure, the machining efficiency can be increased. <​​​​​​​​​​ [Figure 3] This graph shows the relationship between the volume removed and the processing time in the electrical discharge machining method according to Embodiment 1 and the electrical discharge machining method using a complete electrode. [Figure 4] This diagram shows a comparison of electrical discharge machining types and machining speeds. [Modes for carrying out the invention]

[0008] Embodiment 1 Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a perspective view showing an example of an electrical discharge machining method according to Embodiment 1.

[0009] The hollow electrode 11 is an electrode that mimics the contour of the desired machining shape. The hollow electrode 11 has the same shape in the direction (x-direction) in which the electrode is moved to hollow out the workpiece 21. By moving the hollow electrode 11 in the hollowing direction, the workpiece 21 is machined into the desired shape (hereinafter referred to as hollowing).

[0010] The reinforcing section 12 is a beam-like column connecting two points on the contour of the hollow electrode 11. The reinforcing section 12 also has the same shape with respect to the direction in which the electrode is moved for hollowing (x-direction). The reinforcing section 12 provides rigidity in the direction perpendicular to the processing operation direction (x-direction) (y-direction).

[0011] Figure 2 is a graph showing the relationship between the volume removed and the machining time in the electrical discharge machining method according to Embodiment 1. In Figure 2, the horizontal axis represents the machining time, and the vertical axis represents the volume removed to achieve the desired shape.

[0012] As shown in Figure 2, hollowing with a hollow electrode can achieve the desired volume of material removal in a shorter processing time than electrical discharge machining with a full-shape electrode.

[0013] Figure 3 shows the results of machining a groove with dimensions of φ3mm × depth 100mm × length 100mm × taper angle 3° on a material equivalent to SKD61, as shown in the lower part of Figure 1. Note that SKD61 is an alloy steel for hot work dies as specified in the JIS standard (G4404: Alloy Tool Steel).

[0014] Figure 3 is a graph showing the relationship between the volume removed and the processing time in the electrical discharge machining method according to Embodiment 1 and the electrical discharge machining method using a full-form electrode. In Figure 3, the horizontal axis represents the processing time, and the vertical axis represents the volume removed for the target shape. As shown in Figure 3, compared to conventional electrical discharge machining using a full-form electrode, the hollowing process using a hollow electrode reduces the processing time by approximately half.

[0015] Next, we will explain the differences in machining speed depending on the type of electrical discharge machining using Figure 4. Figure 4 is a diagram comparing the types of electrical discharge machining and their machining speeds. Figure 4(a) shows an example of electrical discharge machining using a complete electrode. Here, let V be the machining speed for electrical discharge machining using a complete electrode.

[0016] Figure 4(b) shows an example of electrical discharge machining using a plate-shaped electrode without reinforcement. With this plate-shaped electrode without reinforcement, sufficient rigidity cannot be ensured against heat input from the side of the electrode, and the machining speed must be reduced to less than V.

[0017] Figure 4(c) shows an example of electrical discharge machining using an electrode with reinforcement as described in this disclosure. The electrode with reinforcement ensures sufficient rigidity against heat input from the side of the electrode, and the machining speed can be greater than V.

[0018] Thus, according to the electrical discharge machining method of Embodiment 1, it is possible to minimize the volume directly removed by electrical discharge without reducing the machining conditions, thereby increasing machining efficiency.

[0019] Furthermore, according to the machining electrical discharge method of Embodiment 1, by using an electrode that mimics the contour of the desired machined shape and minimizing the volume removed by electrical discharge, a die-sinking electrical discharge machining method that hollows out the workpiece can be realized.

[0020] Moreover, according to the electrical discharge machining method of Embodiment 1, by providing reinforcement inside the hollow electrode, rigidity can be imparted in the direction perpendicular to the machining operation direction, and high-efficiency punching machining can be realized without reducing the electrical discharge machining conditions.

[0021] Note that the present invention is not limited to the above-described embodiments, and can be appropriately modified without departing from the gist. For example, in the above-described embodiments, a V-shaped electrode is used as an example, but reinforcement may be provided in a U-shape, a C-shape, a circular shape, or any other free shape.

Explanation of Reference Numerals

[0022] 11 Hollow electrode 12 Reinforcement part 21 Workpiece to be machined

Claims

[Claim 1] An electrical discharge machining method for carving a shape by hollowing out a metal material using a hollow electrode that has the contour of the desired processed shape and has reinforcing parts connecting two points on the contour.

Images