Wire EDM

Abstract

To provide a wire electric discharge machine that is more effective in reducing and suppressing electrical noise. [Solution] The wire electric discharge machine is a wire electric discharge machine that performs electric discharge machining on a workpiece by applying a voltage between the electrodes of a wire electrode WE and the workpiece immersed in machining fluid, and is equipped with a machine 12 having a lower part 12a including a machining tank 14 in which the workpiece is immersed in machining fluid, and an upper part 12b located above the lower part, conductive cloth 40 that electrically connects the lower part and upper part, and a magnet 42 arranged on at least one of the lower part or upper part to hold the conductive cloth in place.

Description

[Technical Field]

[0001] The present disclosure relates to a wire electrical discharge machine. [Background technology]

[0002] A wire electric discharge machine applies a voltage between a wire electrode and a workpiece to machine the workpiece. An example of a wire electric discharge machine is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-210818. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-210818 Summary of the Invention [Problem to be solved by the invention]

[0004] Recently, there has been a demand for better techniques for reducing and suppressing electrical noise emitted by wire electrical discharge machines.

[0005] The present disclosure aims to solve the above-mentioned problems. [Means for solving the problem]

[0006] One aspect of the present disclosure is a wire electric discharge machine that performs electric discharge machining on a workpiece immersed in a machining fluid by applying a voltage between the electrodes of a wire electrode and the workpiece, the wire electric discharge machine comprising: a machine having a lower section including a machining tank in which the workpiece is immersed in the machining fluid; and an upper section located above the lower section; a conductive cloth electrically connecting the lower section and the upper section; and a magnet disposed on at least one of the lower section and the upper section to hold the conductive cloth in place. [Effects of the Invention]

[0007] According to the present disclosure, a wire electric discharge machine that is better in terms of reducing and suppressing electrical noise can be provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a wire electric discharge machine according to one embodiment. [Figure 2] FIG. 2 is a perspective view of a wire electric discharge machine according to one embodiment. [Figure 3] FIG. 3 is a perspective view of a wire electric discharge machine according to the first modification. [Figure 4] FIG. 4 is a perspective view of a wire electric discharge machine according to the second modification. DETAILED DESCRIPTION OF THE INVENTION

[0009] Wire-cut electrical discharge machines generate electrical noise, such as high-frequency noise, when performing electrical discharge machining. Possible countermeasures for the electrical noise generated by wire-cut electrical discharge machines include shielding the radiated electrical noise with electromagnetic wave shielding materials and suppressing the generation of electrical noise itself. For example, it is conceivable to reduce the electrical noise by implementing noise countermeasures in the circuit (discharge circuit) that generates the pulse voltage used in electrical discharge machining. However, in this case, there is a risk that the voltage waveform of the pulse voltage will change due to a change in the configuration of the discharge circuit, resulting in an unintended change in the machining performance of the wire-cut electrical discharge machine.

[0010] Based on the above preliminary explanation, one embodiment will be described below. Note that the X, Y, and Z directions in the following explanation are mutually orthogonal. The X and Y directions may each be parallel to a horizontal plane. The Z direction may coincide with the vertical direction (up-down direction).

[0011] (One embodiment) 1 and 2 are each a perspective view of a wire electric discharge machine 10 according to one embodiment.

[0012] The wire electric discharge machine 10 is a machine tool that applies a voltage (pulse voltage) between a wire electrode WE and a workpiece to perform electric discharge machining on the workpiece. The wire electric discharge machine 10 includes a machining device 12. The machining device 12 has a lower portion 12a and an upper portion 12b.

[0013] The lower portion 12a of the processing machine 12 includes a processing tank 14, a bed 16, a lower arm 18, and a processing fluid tank 20. The processing tank 14, the bed 16, the lower arm 18, and the processing fluid tank 20 are each formed, for example, by casting. The bed 16 is a base that is placed on an installation surface such as a factory floor. When the processing machine 12 is installed on the installation surface, the X and Y directions are parallel to the installation surface. Therefore, when the installation surface is parallel to a horizontal plane, the X and Y directions are each horizontal.

[0014] A machining tank 14 is provided on the bed 16. A machining table (not shown) for supporting the workpiece is provided inside the machining tank 14. The machining table and the workpiece are immersed in a machining fluid inside the machining tank 14. The machining fluid includes, for example, water, but may also include oil.

[0015] The lower arm 18 extends from a column 38 (described later) to the inside of the machining tank 14. The lower arm 18 is provided with a lower wire guide 22. The lower wire guide 22 supports the wire electrode WE together with an upper wire guide 34 (described later). Note that a wire recovery path 18a may be formed inside the lower arm 18, which is a path that guides the wire electrode WE fed to the lower wire guide 22 to a recovery box 24.

[0016] The machining fluid tank 20 is a tank that stores machining fluid. The machining fluid stored in the machining fluid tank 20 can be supplied to the machining tank 14 by a pump or the like (not shown). The machining fluid may circulate between the machining fluid tank 20 and the machining tank 14.

[0017] Although not shown, the lower portion 12a of the processing machine 12 may include a Y-axis slider and an X-axis slider. The Y-axis slider and the X-axis slider are each disposed between the bed 16 and the processing tank 14. The processing tank 14 is supported on the bed 16 via the Y-axis slider and the X-axis slider. The Y-axis slider is a slider that can move in the Y direction. The X-axis slider is a slider that can move in the X direction. One of the Y-axis slider and the X-axis slider is disposed on top of the other. As the Y-axis slider moves in the Y direction, the processing tank 14 may move relative to the bed 16 in the Y direction. As the X-axis slider moves in the X direction, the processing tank 14 may move relative to the bed 16 in the X direction. Each of the Y-axis slider and the X-axis slider may be driven by an actuator, such as an electric motor or a ball screw.

[0018] The processing table provided inside the processing tank 14 may be moved by the above-mentioned X-axis slider or Y-axis slider. In this case, the processing table may move in the Y direction relative to the bed 16 and the processing tank 14 in response to the movement of the Y-axis slider in the Y direction. Furthermore, the processing table may move in the X direction relative to the bed 16 and the processing tank 14 in response to the movement of the X-axis slider in the X direction.

[0019] The upper portion 12b of the processing machine 12 includes a head 26 and an upper arm 28. The head 26 and the upper arm 28 are formed by casting, for example.

[0020] The head 26 is appropriately provided with a wire bobbin 30 and a plurality of feeding members 32 (321, 322). A wire electrode WE is wound around the wire bobbin 30. The feeding member 32 is, for example, a rotatable roller member. The feeding member 32 may be rotationally driven by a driving source (such as an electric motor) (not shown).

[0021] The upper arm 28 extends from the head 26 toward the processing tank 14. The upper arm 28 is provided with an upper wire guide 34. The upper wire guide 34 guides (feeds) the wire electrode WE supplied to the upper arm 28 downward (to the lower wire guide 22 in the processing tank 14).

[0022] The wire electrode WE is stretched between the upper wire guide 34 and the lower wire guide 22. A workpiece is placed between the upper wire guide 34 and the lower wire guide 22, whereby a gap is formed between the stretched wire electrode WE and the workpiece. The above-described electric discharge machining can be performed by applying a voltage to this gap.

[0023] The wire electric discharge machine 10 may be provided with a discharge device (discharge circuit) (not shown) that applies a voltage between the electrodes. The lower portion 12a may be provided with a plurality of winding members 36 (361-363) that wind the wire electrode WE. The winding members 36 are, for example, rotatable roller members. The winding members 36 may be rotationally driven by a drive source (such as an electric motor) (not shown).

[0024] The processing machine 12 further includes a column 38. The column 38 is a member that connects the upper portion 12b and the lower portion 12a. The upper portion 12b and the lower portion 12a are physically and electrically connected by the column 38. The column 38 is connected to the bed 16 and the head 26, for example.

[0025] The column 38 is located behind the machining tank 14. That is, the direction from the column 38 toward the machining tank 14 along the Y direction coincides with the forward direction Y1 of the wire electric discharge machine 10. Furthermore, the direction from the machining tank 14 toward the column 38 along the Y direction coincides with the rearward direction Y2 of the wire electric discharge machine 10.

[0026] The wire electric discharge machine 10 further includes a conductive cloth 40 and one or more magnets 42 .

[0027] The conductive cloth 40 is a conductive cloth member. The conductive cloth 40 has, for example, cloth fibers and conductive plating applied to the cloth fibers. The conductive plating may be metal plating. The conductive cloth 40 is provided so as to cover the lower portion 12a and the upper portion 12b. As a result, the conductive cloth 40 electrically connects the lower portion 12a and the upper portion 12b. The conductive cloth 40 may be formed of braided conductive fibers (metal fibers, etc.). The conductive cloth 40 also has a front surface 40s1 and a rear surface 40s2. The rear surface 40s2 is the surface of the conductive cloth 40 facing the processing tank 14. The rear surface 40s2 is conductive. For example, the above-mentioned conductive plating is included on the rear surface 40s2. In contrast, the front surface 40s1 is the surface of the conductive cloth 40 opposite the rear surface 40s2. It is preferable that the front surface 40s1 be insulating. For example, the above-mentioned cloth fibers are included on the front surface 40s1. The front surface 40s1 may have insulating properties by providing an insulating material on the front surface 40s1 of the conductive cloth 40. In this embodiment, the direction from the rear surface 40s2 toward the front surface 40s1 coincides with the front direction Y1.

[0028] The magnet 42 is disposed on at least one of the lower portion 12a and the upper portion 12b and fastens the conductive cloth 40. This fixes the conductive cloth 40 to the upper portion 12b. For example, with the conductive cloth 40 disposed between the upper portion 12b (the head 26, etc.) and the magnet 42, the magnet 42 may be attracted to the upper portion 12b through the conductive cloth 40 (front surface 40s1), thereby fixing the conductive cloth 40 to the upper portion 12b.

[0029] When the conductive cloth 40 is fixed to the upper part 12b by the magnet 42, the conductive cloth 40 may be unfixed to the lower part 12a. In this case, the conductive cloth 40 may contact the lower part 12a by hanging over an edge portion 44 included in the lower part 12a. The edge portion 44 included in the lower part 12a is, for example, the upper edge 16e of the bed 16, the upper edge 20e of the machining fluid tank 20, or the upper edge 14e of the machining tank 14 described below. The upper edge 16e of the bed 16, the upper edge 20e of the machining fluid tank 20, the upper edge 14e of the machining tank 14, etc. may have a portion that is located further forward in the forward direction Y1 than the front end portion 26f of the head 26 (upper part 12b).

[0030] In addition, when the wire electric discharge machine 10 is equipped with multiple magnets 42, the conductive cloth 40 may be fixed to the upper part 12b by the magnets 42 arranged on the upper part 12b, and may also be fixed to the lower part 12a by the magnets 42 arranged on the lower part 12a.

[0031] It is preferable that the conductive cloth 40 covers at least the front portion 14f of the processing tank 14 in the lower portion 12a. In this case, it is more preferable that the entire front portion 14f of the processing tank 14 is covered by the conductive cloth 40. Note that the direction from the rear portion 14r of the processing tank 14 toward the front portion 14f coincides with the above-mentioned forward direction Y1.

[0032] According to this embodiment, the wire electric discharge machine 10 exhibits the following advantageous effects, for example.

[0033] The conductive cloth 40 electrically connects the upper portion 12b of the processing machine 12 to the lower portion 12a of the processing machine 12. This establishes electrical continuity between the upper portion 12b and the lower portion 12a. That is, the conductive cloth 40 adds an electrical contact point between the upper portion 12b and the lower portion 12a, which are electrically connected via the column 38, to the processing machine 12. As a result, the potential difference between the upper portion 12b and the lower portion 12a can be reduced compared to when the upper portion 12b and the lower portion 12a are electrically connected only via the column 38. This reduction in potential difference can reduce electrical noise emitted from the processing machine 12.

[0034] The conductive cloth 40 may have a relatively large surface area compared to sheet metal members, conductive cables, etc. Alternatively, a user may easily or inexpensively procure a conductive cloth 40 with a relatively large surface area. The larger the surface area of ​​the conductive cloth 40, the better the conductive cloth 40 can reduce the potential difference between the upper portion 12b and the lower portion 12a. Therefore, according to this embodiment, the potential difference between the upper portion 12b and the lower portion 12a can be better reduced compared to when electrical contact between the upper portion 12b and the lower portion 12a is added to the processing machine 12 using sheet metal members, conductive cables, etc.

[0035] The conductive cloth 40 is fastened to at least one of the upper portion 12b and the lower portion 12a of the processing machine 12 by the magnet 42. The task of attaching and detaching the magnet 42 to the upper portion 12b or the lower portion 12a is a relatively simple task for a user. Therefore, according to this embodiment, the user can easily reduce electrical noise emitted from the processing machine 12.

[0036] Preferably, the conductive cloth 40 is fixed to the upper portion 12b by a magnet 42. This allows the conductive cloth 40 to hang down due to the action of gravity and naturally cover the lower portion 12a. When the conductive cloth 40 is fixed to the upper portion 12b by a magnet 42, the conductive cloth 40 may be left unfixed to the lower portion 12a. In this case, the conductive cloth 40 does not necessarily contact the lower portion 12a, but the surface of the conductive cloth 40 and the surface of the lower portion 12a (such as the surface of the front portion 14f of the processing tank 14) may be brought into close proximity to a certain extent, thereby allowing capacitive coupling between the conductive cloth 40 and the lower portion 12a. This allows at least electrical connection between the conductive cloth 40 and the lower portion 12a to be achieved and reduces electrical noise.

[0037] The conductive cloth 40 may maintain contact with the lower portion 12a by hanging over an edge portion 44 included in the lower portion 12a. This allows the conductive cloth 40 to effectively reduce the potential difference between the upper portion 12b and the lower portion 12a. As described above, the upper edge 16e of the bed 16, the upper edge 20e of the machining fluid tank 20, the upper edge 14e of the machining tank 14, etc. may have portions located further forward in the forward direction Y1 than the front end portion 26f of the head 26 (upper portion 12b). In this case, the user can easily hang the conductive cloth 40 over the edge portion 44 by fixing the conductive cloth 40 to the upper portion 12b and arranging the conductive cloth 40 so as to cover the front portion 14f of the machining tank 14.

[0038] The conductive cloth 40 has a front surface 40s1 and a rear surface 40s2. The front surface 40s1 is preferably insulating. This reduces the risk of electric shock to a user who comes into contact with the conductive cloth 40. The rear surface 40s2 is conductive. This provides the processing machine 12 with an additional electrical contact point between the upper portion 12b and the lower portion 12a.

[0039] An embodiment may be modified as described below.

[0040] (Variation 1) FIG. 3 is a perspective view of a wire electric discharge machine 10 according to the first modification.

[0041] When the conductive cloth 40 is fixed to one of the lower portion 12a and the upper portion 12b by the magnet 42, the conductive cloth 40 may be fixed to the other of the lower portion 12a and the upper portion 12b by a fixing member 46 other than the magnet 42.

[0042] For example, if the magnet 42 is disposed on the upper portion 12b, the fixing member 46 may be disposed on the lower portion 12a. The conductive cloth 40 is fixed to the upper portion 12b by the magnet 42, and the fixing member 46 is fixed to the lower portion 12a. The contact state between the conductive cloth 40 and the upper portion 12b is maintained by the magnet 42, and the contact state between the conductive cloth 40 and the lower portion 12a is maintained by the fixing member 46.

[0043] The fixing member 46 is, for example, a fastening member such as a screw, but is not limited to this.

[0044] (Variation 2) FIG. 4 is a perspective view of a wire electric discharge machine 10 according to the second modification.

[0045] The conductive cloth 40 may be disposed on the side of the processing machine 12 to electrically connect the upper portion 12b and the lower portion 12a. In this case, the wire electric discharge machine 10 may be provided with a plurality of conductive cloths 40, including a first conductive cloth 401 that covers the front portion 14f of the processing tank 14 and a second conductive cloth 402 that is disposed on the side of the processing machine 12.

[0046] (Combination of multiple modifications) The above-described multiple modifications may be combined as appropriate within a range that does not cause inconsistency.

[0047] According to the above-described embodiment and the modified example thereof, it is possible to provide a wire electric discharge machine 10 that is better in terms of reducing and suppressing electrical noise.

[0048] The following additional notes are further disclosed regarding the above embodiment.

[0049] (Appendix 1) The wire electric discharge machine (10) according to the present disclosure is a wire electric discharge machine that performs electric discharge machining on a workpiece by applying a voltage between a wire electrode (WE) and the workpiece immersed in a machining fluid, and comprises a machine (12) having a lower part (12a) including a machining tank (14) in which the workpiece is immersed in the machining fluid, and an upper part (12b) located above the lower part, a conductive cloth (40) that electrically connects the lower part and the upper part, and a magnet (42) that is disposed on at least one of the lower part and the upper part and that fastens the conductive cloth.

[0050] (Appendix 2) In the wire electric discharge machine according to Supplementary Note 1, the conductive cloth may be fixed to the upper part by the magnet and may be unfixed to the lower part.

[0051] (Appendix 3) In the wire electric discharge machine described in Supplementary Note 2, the conductive cloth may contact the lower part by hanging over an edge (44) included in the lower part.

[0052] (Appendix 4) A wire electric discharge machine according to any one of Appendices 1 to 3 may further include a fixing member (46) other than the magnet that fastens the conductive cloth to the lower portion, and the magnet may be disposed in at least the upper portion of the lower and upper portions.

[0053] (Appendix 5) In the wire electric discharge machine described in any one of Appendices 1 to 4, at least the front part (14f) of the machining tank in the lower part may be covered by the conductive cloth, and the direction from the rear part (14r) of the machining tank toward the front part may coincide with the direction from a column (38) connecting the lower part and the upper part toward the machining tank.

[0054] (Appendix 6) In the wire electric discharge machine according to any one of Supplementary Notes 1 to 5, the conductive cloth may have cloth fibers and conductive plating applied to the cloth fibers.

[0055] (Appendix 7) In the wire electric discharge machine according to any one of Supplementary Notes 1 to 6, the upper portion may include a head (26) that supplies the wire electrode to the machining tank.

[0056] (Appendix 8) In the wire electric discharge machine described in Appendix 7, the head may include a wire bobbin (30) around which the wire electrode is wound, and an upper arm (28) that delivers the wire electrode taken out of the wire bobbin to the machining tank.

[0057] (Appendix 9) In the wire electric discharge machine described in Appendix 7 or 8, the lower part may further include a bed (16) that supports the machining tank, and the bed and the head may be electrically connected via a column.

[0058] (Appendix 10) In the wire electric discharge machine described in any one of Appendices 1 to 9, the conductive cloth may have a rear surface (40s2) that faces the machining tank and is conductive, and a front surface (40s1) that is the surface opposite the rear surface and is insulating.

[0059] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments. [Explanation of symbols]

[0060] 10: Wire EDM machine 12: Processing machine 12a: Lower 12b: Upper part 14: Processing tank 14f: Front 14r: rear 16: Bed 26: Head 28: Upper arm 30: Wire bobbin 38: Column 40:Conductive cloth 40s1:Front 40s2: Rear 42: Magnet 44: Edge 46: Fixing member WE: Wire electrode

Claims

1. 1. A wire electric discharge machine that performs electric discharge machining on a workpiece by applying a voltage between a wire electrode and the workpiece immersed in a machining liquid, a processing machine having a lower portion including a processing tank in which the workpiece is immersed in the processing liquid, and an upper portion located above the lower portion; a conductive cloth electrically connecting the lower portion and the upper portion; a magnet disposed on at least one of the lower portion and the upper portion for fastening the conductive cloth; A wire electric discharge machine comprising:

2. 2. The wire electric discharge machine according to claim 1, The conductive cloth is fixed to the upper part by the magnet and is not fixed to the lower part.

3. 3. The wire electric discharge machine according to claim 2, A wire electric discharge machine, wherein the conductive cloth contacts the lower part by hanging over an edge included in the lower part.

4. 2. The wire electric discharge machine according to claim 1, a fixing member other than the magnet that fastens the conductive cloth to the lower portion, The wire electric discharge machine, wherein the magnet is disposed in at least the upper portion of the lower portion and the upper portion.

5. The wire electric discharge machine according to any one of claims 1 to 4, At least a front portion of the processing tank in the lower portion is covered with the conductive cloth, A wire electric discharge machine, wherein a direction from the rear of the machining tank toward the front thereof coincides with a direction from a column connecting the lower portion and the upper portion toward the machining tank.

6. The wire electric discharge machine according to any one of claims 1 to 4, The conductive cloth is Fabric fibers and Conductive plating applied to the fabric fibers; A wire electric discharge machine having a

7. The wire electric discharge machine according to any one of claims 1 to 4, The upper part of the wire electric discharge machine includes a head that supplies the wire electrode to the machining tank.

8. 8. The wire electric discharge machine according to claim 7, The head a wire bobbin around which the wire electrode is wound; an upper arm that delivers the wire electrode taken out from the wire bobbin to the machining tank; A wire electric discharge machine comprising:

9. 8. The wire electric discharge machine according to claim 7, The lower portion further includes a bed supporting the processing tank; The wire electric discharge machine, wherein the bed and the head are electrically connected via a column.

10. The wire electric discharge machine according to any one of claims 1 to 4, The conductive cloth has a rear surface facing the machining tank and having electrical conductivity, and a front surface opposite the rear surface and having electrical insulation.

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