Electrical discharge machine

Abstract

According to an aspect of the present disclosure, provided is an electric discharge machine (10) for performing electric discharge machining on an aluminum-based material, a machining liquid used during electric discharge machining in the electric discharge machine (10) comprising: one or more cations selected from among potassium ions, calcium ions, sodium ions, and magnesium ions; and at least one anion selected from the group consisting of a sulfate ion, a sulfite ion, a disulfite ion, a bisulfite ion, a hydroxide ion, a nitrate ion, and a nitrite ion.

Description

Technical Field

[0001] The present disclosure relates to an electrical discharge machine. Background Art

[0002] International Publication No. 2006 / 126248 discloses an electrical discharge machine. Summary of the invention

[0003] Recently, better electrical discharge machines are expected.

[0004] The method disclosed herein is an electric discharge machine for performing electric discharge machining on aluminum materials. The machining fluid used by the electric discharge machine during electric discharge machining contains: any one or more cations of potassium ions, calcium ions, sodium ions and magnesium ions; and any one or more anions of sulfate ions, sulfite ions, disulfite ions, bisulfite ions, hydroxide ions, nitrate ions and nitrite ions. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 This is a schematic diagram of a wire electrical discharge machine. DETAILED DESCRIPTION

[0006] During the machining process, the EDM uses a filter to filter the used machining fluid. The sludge and the like are removed from the machining fluid by filtering, and the sludge and the like contained in the machining fluid adhere to the filter. The EDM reuses the filtered machining fluid. When the pressure required to be applied to the machining fluid to pass through the filter exceeds a specified value, the operator needs to replace the filter. Therefore, in the EDM, it is necessary to extend the life of the filter. The life of the filter refers to the period from when the filter is replaced with a new one until the pressure required to be applied to the machining fluid to pass through the filter exceeds a specified value.

[0007] The filter life when machining aluminum materials is shorter than that when machining iron materials. For example, when machining iron and aluminum materials of the same thickness, the filter life when machining aluminum materials is 10% to 25% shorter than that when machining iron materials.

[0008] Therefore, when machining aluminum-based materials using an electric discharge machine, there is a problem that the amount of discarded filters increases. The present disclosure aims to extend the life of a filter.

[0009] [First embodiment] [Structure of Wire EDM] Figure 11 is a schematic diagram of a wire electrical discharge machine 10. The wire electrical discharge machine 10 includes a machine body 12, a machining fluid treatment device 14, and a numerical controller 16. The wire electrical discharge machine 10 corresponds to the electrical discharge machine of the present invention.

[0010] The processing machine body 12 has a processing tank 18. The processing machine body 12 performs electrical discharge processing on a workpiece in a state where a processing fluid is stored in the processing tank 18.

[0011] The machining fluid treatment device 14 includes a dirty water tank 20 , a clean water tank 22 , and an ion exchange unit 24 .

[0012] The waste water tank 20 is connected to the machining tank 18 via a drainage path 26. The machining fluid is discharged from the machining tank 18 to the waste water tank 20. The machining fluid discharged from the machining tank 18 to the waste water tank 20 contains sludge and the like generated during the electrical discharge machining of the workpiece.

[0013] The sewage tank 20 is connected to the clean water tank 22 via a filter path 28. A first pump 30 and a filter 32 are provided in the filter path 28. The first pump 30 draws the machining fluid from the sewage tank 20 and delivers it to the clean water tank 22. The filter 32 filters the machining fluid delivered from the sewage tank 20 to the clean water tank 22 and removes sludge and the like from the machining fluid.

[0014] The clean water tank 22 is connected to the ion exchange unit 24 via a circulation path 34. A second pump 36 and a valve 38 are provided in the circulation path 34. The ion exchange unit 24 has an ion exchange resin inside. The second pump 36 circulates the machining fluid between the clean water tank 22 and the ion exchange unit 24. The ion exchange resin exchanges the ions contained in the machining fluid passing through the ion exchange resin with other ions. As a result, the resistivity value of the machining fluid increases.

[0015] The machining tank 18 is connected to the clean water tank 22 via a water supply path 39. The machining tank 18 is supplied with a machining fluid having an adjusted resistivity value.

[0016] The valve 38 adjusts the amount of the machining fluid that circulates between the clean water tank 22 and the ion exchange unit 24 .

[0017] The numerical control device 16 controls the processing machine body 12. In addition, the numerical control device 16 controls the opening degree or opening time of the valve 38 based on the resistivity of the processing fluid measured by the resistivity measuring unit 40. The resistivity value measuring unit 40 measures the resistivity value of the processing fluid stored in the clean water tank 22. Thus, the resistivity value of the processing fluid in the clean water tank 22 is maintained at a predetermined value.

[0018] [About ions contained in machining fluid] The machining fluid used in the wire electrical discharge machine 10 of the present invention contains one or more ions of the following cations: These cations are potassium ions, calcium ions, sodium ions, and magnesium ions.

[0019] Furthermore, the machining fluid used in the wire electrical discharge machine 10 of the present invention contains one or more of the following anions: sulfate ion, sulfite ion, disulfite ion, hydrogensulfite ion, hydroxide ion, nitrate ion, and nitrite ion.

[0020] Among the above-mentioned ions, the following ions are ions contained in the machining fluid by adding a chemical to the machining fluid: potassium ion, calcium ion, sodium ion, magnesium ion, sulfate ion, sulfite ion, disulfite ion, hydrogensulfite ion, hydroxide ion, nitrate ion, and nitrite ion.

[0021] The chemicals to be added are, for example, the following chemicals: sodium bisulfite, sodium carbonate, sodium sulfate, calcium hydroxide, sodium disulfite (sodium pyrosulfite), potassium disulfite (potassium pyrosulfite), magnesium sulfate, magnesium sulfate heptahydrate, and the like.

[0022] Of the above-mentioned ions, sodium ions and hydroxide ions are contained in the machining fluid by causing the machining fluid to pass through the ion exchange resin of the ion exchange unit 24 .

[0023] In the ion exchange section 24, an ion exchange resin having a carboxyl group or a sulfonic acid group as an exchange group may be used as a cation exchange resin. In the ion exchange section 24, an ion exchange resin having an amino group introduced as a functional group may be used as an anion exchange resin.

[0024] In the wire electrical discharge machine 10 of the present disclosure, when electrical discharge machining is performed on a workpiece made of an aluminum-based material, aluminum oxide and aluminum trihydrate are generated.

[0025] In the wire electric discharge machine 10, the machining fluid after machining contains copper ions, zinc ions, hydrogen ions, and hydroxide ions. In the wire electric discharge machine 10 of the present disclosure, the copper ions, zinc ions, hydrogen ions, and hydroxide ions are not removed.

[0026] [About experimental results] The inventors of the present application conducted an experiment to find the life of the filter 32 by performing electrical discharge machining using a plurality of machining fluids containing different ions.

[0027] It was confirmed that the life of the filter 32 was prolonged when the machining fluid contained any one of potassium ions, calcium ions, sodium ions, magnesium ions, hydrogen ions, sulfate ions, sulfite ions, hydrogensulfite ions, and hydroxide ions.

[0028] On the other hand, when the machining fluid contains chloride ions, it is not confirmed that the life of the filter 32 is prolonged.

[0029] Furthermore, it was not confirmed that the life of the filter 32 was prolonged even when the machining fluid contained both hydrogen ions and hydroxide ions.

[0030] When sodium bisulfite is added to the machining fluid, aluminum oxide and aluminum trihydrate are generated in the machining fluid during electrical discharge machining of aluminum-based materials. On the other hand, when sodium bisulfite is not added to the machining fluid, aluminum hydroxide is generated in the machining fluid during electrical discharge machining of aluminum-based materials. It is considered that by adding sodium bisulfite to the machining fluid, aluminum oxide and aluminum trihydrate are generated to replace the aluminum hydroxide that shortens the life of the filter 32.

[0031] [Effects] When aluminum-based materials are processed by the wire electric discharge machine 10, aluminum hydroxide is generated in the conventional processing fluid. The surface of aluminum hydroxide is sticky. Therefore, aluminum hydroxide easily clogs the mesh of the filter 32, and the life of the filter 32 is shortened. When the life of the filter 32 is shortened, there is a problem that the amount of waste of the filter 32 increases. Therefore, in the wire electric discharge machine 10, even when electric discharge processing is performed on aluminum-based materials, the life of the filter 32 can be extended.

[0032] In the wire electric discharge machine 10 of the present embodiment, the machining fluid used in the electric discharge machining contains one or more of the following cations. These cations are potassium ions, calcium ions, sodium ions, and magnesium ions. In addition, the machining fluid used in the electric discharge machining contains one or more of the following anions. These anions are sulfate ions, sulfite ions, disulfite ions, hydrogensulfite ions, hydroxide ions, nitrate ions, and nitrite ions. As a result, the wire electric discharge machine 10 can extend the life of the filter 32.

[0033] In the wire electric discharge machine 10 of the present embodiment, the following ions are contained in the machining fluid by adding a chemical to the machining fluid. These ions are potassium ions, calcium ions, sodium ions, magnesium ions, sulfate ions, sulfite ions, disulfite ions, hydrogen sulfite ions, hydroxide ions, nitrate ions, and nitrite ions. Thus, these ions can be contained in the machining fluid in a simple manner.

[0034] In the wire electric discharge machine 10 of the present embodiment, the following ions are contained in the machining fluid by passing the machining fluid through an ion exchange resin. The ions are sodium ions and hydroxide ions. Thus, these ions can be contained in the machining fluid by a simple method.

[0035] In addition, the wire electrical discharge machine 10 of the present embodiment generates aluminum oxide and aluminum trihydrate by performing electrical discharge machining on an aluminum-based material. Thus, the wire electrical discharge machine 10 can extend the life of the filter 32 .

[0036] The following additional remarks are disclosed in relation to the above-mentioned embodiment.

[0037] (Note 1) An electric discharge machine (10) for performing electric discharge machining on aluminum materials, wherein a machining fluid used during the electric discharge machining comprises: at least one cation selected from potassium ions, calcium ions, sodium ions, and magnesium ions; and at least one anion selected from sulfate ions, sulfite ions, disulfite ions, hydrogensulfite ions, hydroxide ions, nitrate ions, and nitrite ions. Thus, the electric discharge machine can extend the life of a filter.

[0038] (Note 2) In the electrical discharge machine described in Appendix 1, the potassium ions, calcium ions, sodium ions, magnesium ions, sulfate ions, sulfite ions, disulfite ions, hydrogen sulfite ions, hydroxide ions, nitrate ions, and nitrite ions contained in the machining fluid used in the electrical discharge machine during electrical discharge machining may be ions contained in the machining fluid by adding a chemical to the machining fluid. Thus, these ions can be contained in the machining fluid by a simple method.

[0039] (Note 3) In the electrical discharge machine described in Supplement 1 or Supplement 2, the electrical discharge machine has an ion exchange resin, and the sodium ions and the hydroxide ions contained in the machining fluid used in the electrical discharge machine during electrical discharge machining may also be ions contained in the machining fluid by passing the machining fluid through the ion exchange resin. Thus, these ions can be contained in the machining fluid in a simple manner.

[0040] (Note 4) In the electrical discharge machine according to any one of Supplementary Notes 1 to 3, the electrical discharge machine may generate aluminum oxide and aluminum oxide trihydrate by performing electrical discharge machining on the aluminum-based material. Thus, the electrical discharge machine can extend the life of a filter.

[0041] Although the embodiments of the present disclosure have been described in detail, the present disclosure is not limited to the above-mentioned embodiments. These embodiments may be subjected to various additions, substitutions, changes, partial deletions, etc., without departing from the scope of the main idea of ​​the invention, or without departing from the idea and main idea of ​​the present invention derived from the contents recorded in the claims and their equivalents. For example, in the above-mentioned embodiments, the order of each action and the order of each processing are shown as an example and are not limited to this. In addition, when numerical values ​​or mathematical formulas are used in the description of the above-mentioned embodiments, the same applies. Explanation of symbols

[0042] 10…Wire EDM.

Claims

1. An electrical discharge machine (10) for performing electrical discharge machining on aluminum-based materials, characterized in that: The machining fluids used in EDM include: Any one or more cations selected from potassium ion, calcium ion, sodium ion and magnesium ion; and Any one or more anions selected from the group consisting of sulfate ion, sulfite ion, disulfite ion, hydrogensulfite ion, hydroxide ion, nitrate ion, and nitrite ion.

2. The electrical discharge machine according to claim 1, characterized in that The potassium ion, the calcium ion, the sodium ion, the magnesium ion, the sulfate ion, the sulfite ion, the disulfite ion, the hydrogen sulfite ion, the hydroxide ion, the nitrate ion, and the nitrite ion are ions contained in the machining fluid by adding a chemical to the machining fluid.

3. The electrical discharge machine according to claim 1 or 2, characterized in that: With ion exchange resin, The sodium ions and the hydroxide ions are ions contained in the machining fluid by passing the machining fluid through the ion exchange resin.

4. The electrical discharge machine according to any one of claims 1 to 3, characterized in that Aluminum oxide and aluminum oxide trihydrate are produced by performing electrical discharge machining on the aluminum-based material.

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