Wire discharge machining

Abstract

A wire electric discharge machining device (10) comprises: a hollow arm (22) that passes through a machining vessel (12) and guides a wire electrode (24) to the outside of the machining vessel (12); a driving mechanism (14) that changes the relative positions of the machining vessel (12) and the arm (22) at least in the direction of extension of the arm (22); a machining fluid inlet (38) that is formed in a first section (30) of the arm (22) positioned inside the machining vessel (12) regardless of the relative positions thereof; and a machining fluid outlet (40) that is formed in a second section (32) of the arm (22) positioned outside the machining vessel (12) regardless of the relative positions thereof.

Description

Technical Field

[0001] The present invention relates to a wire electrical discharge machining apparatus.

Background Art

[0002] The wire electrical discharge machining apparatus disclosed in Japanese Patent Publication No. 3-008892 includes a machining tank and an arm. The machining tank stores a machining liquid. Also, a voltage is applied between the wire electrode and the workpiece in the machining liquid stored in the machining tank.

[0003] The arm penetrates through the machining tank. Therefore, a part of the arm is immersed in the machining liquid in the machining tank. The wire electrode is inserted through the inside of the arm.

Summary of the Invention

[0004] The ratio of the part of the arm immersed in the machining liquid changes according to the change in the relative positional relationship between the arm and the machining tank. Here, the liquid temperature of the machining liquid in the machining tank rises due to the discharge occurring in the machining tank.

[0005] The part of the arm immersed in the machining liquid in the machining tank expands according to the high liquid temperature of the machining liquid. Due to this expansion, the length of the arm changes. That is, the length of the arm changes according to the length of the part of the arm immersed in the machining liquid.

[0006] There is a problem that the machining accuracy deteriorates due to the change in the length of the arm during the execution of wire electrical discharge machining.

[0007] An object of the present invention is to solve the above-described problems.

[0008] One aspect of the present invention is a wire electrical discharge machine that processes a workpiece by generating an electrical discharge between a wire electrode and a workpiece in a processing fluid, the wire electrical discharge machine comprising: a processing tank for storing the processing fluid and containing the workpiece; a hollow arm that penetrates the processing tank and through which the wire electrode is inserted to guide the wire electrode, which has passed through the workpiece, out of the processing tank; a drive mechanism for changing the relative positional relationship between the processing tank and the arm, at least in the extension direction of the arm; a processing fluid inlet formed in a first portion of the arm that is located inside the processing tank regardless of the change in the extension direction of the relative positional relationship, and for guiding the processing fluid into the interior of the arm; and a processing fluid outlet formed in a second portion of the arm that is located outside the processing tank regardless of the change in the extension direction of the relative positional relationship, and for discharging the processing fluid that has entered through the processing fluid inlet to the outside of the arm.

[0009] According to the present invention, the entire arm is temperature-controlled according to the temperature of the machining fluid in the machining tank, so that changes in the length of the arm during electrical discharge machining are suppressed. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a diagram showing the configuration of a wire electrical discharge machining machine according to an embodiment. [Figure 2] Figure 2 shows a wire electrical discharge machining machine when the machining tank moves to a different position than shown in Figure 1 in response to the operation of the drive mechanism. [Figure 3] Figure 3 is a schematic diagram showing the structure of a wire electrical discharge machining machine related to the arm. [Figure 4] Figure 4A is a diagram showing the configuration of a wire electrical discharge machining machine according to Modification 1. Figure 4B is a diagram showing the fluid flow when the second valve is open. [Modes for carrying out the invention]

[0011] [Embodiment] Figure 1 is a diagram showing the configuration of a wire electrical discharge machining machine 10 according to an embodiment.

[0012] Figure 1 shows not only the wire EDM machine 10, but also the X, Y (+Y, -Y), and Z directions. The X direction is parallel to the horizontal plane. The Y direction is also parallel to the horizontal plane, except that the Y direction is perpendicular to the X direction. The Z direction is upward. The Z direction is perpendicular to the horizontal plane.

[0013] The wire electrical discharge machining machine 10 comprises a support section 11, a machining chamber 12, a drive mechanism 14, a table 16, an upper guide block 18, a lower guide block 20, an arm 22, and a wire electrode 24. The interior 28 of the arm 22 is hollow (see also Figure 3). The longitudinal direction (extension direction) of the arm 22 is the Y direction.

[0014] The support structure 11 comprises a bed 11A and a column 11B. The bed 11A is installed on a surface such as the floor of a factory. The column 11B is erected on the bed 11A.

[0015] The processing tank 12, along with the drive mechanism 14, is positioned in the +Y direction relative to the column 11B. The processing tank 12 stores the processing fluid LQ. The processing tank 12 is also supported by the drive mechanism 14.

[0016] The drive mechanism 14 is installed on the bed 11A. The drive mechanism 14 includes a slider 26 that supports the machining tank 12. The slider 26 can slide in the X and Y directions. Therefore, the drive mechanism 14 can move the machining tank 12, for example, in the Y direction, in accordance with the movement of the slider 26. The slider 26 slides, for example, in accordance with the drive of a servo motor.

[0017] In Figure 1, the slider 26 is positioned furthest to the +Y direction within its range of motion.

[0018] Table 16 is immersed in the processing fluid LQ within the processing tank 12. When the processing tank 12 is moved by the drive mechanism 14, table 16 also moves with the processing tank 12.

[0019] Table 16 supports the workpiece W in the processing tank 12. The workpiece W supported by the table 16 is also immersed in the processing liquid LQ in the processing tank 12.

[0020] The upper guide block 18 is supported by the column 11B and is arranged above the workpiece W. The upper guide block 18 guides the wire electrode 24 while supporting it with respect to the workpiece W.

[0021] A voltage is applied between the wire electrode 24 sent to the workpiece W and the workpiece W. Thereby, a discharge occurs between the wire electrode 24 and the workpiece W. In response to this discharge, the workpiece W is processed.

[0022] The lower guide block 20 is immersed in the processing liquid LQ below the workpiece W. The lower guide block 20 guides the wire electrode 24 that has passed through the workpiece W into the interior 28 of the arm 22 while supporting it. The lower guide block 20 includes a nozzle 20a.

[0023] The nozzle 20a is a member for jetting a clean processing liquid LQ upward from the lower guide block 20. The processing liquid LQ jetted by the nozzle 20a removes the sludge generated by processing the workpiece W from between the wire electrode 24 and the workpiece W.

[0024] Further, the wire electrode 24 and the workpiece W are heated by a discharge occurring between them. The processing liquid LQ jetted by the nozzle 20a cools the wire electrode 24 and the workpiece W.

[0025] Note that the processing liquid LQ jetted from the nozzle 20a of the lower guide block 20 is supplied to the nozzle 20a through a nozzle communication pipe 36 arranged in the interior 28 of the arm 22. The description of the nozzle communication pipe 36 will be given later.

[0026] The nozzle that jets the machining fluid LQ may be provided not only in the lower guide block 20 but also in the upper guide block 18. However, the nozzle provided in the upper guide block 18 jets the machining fluid LQ downward.

[0027] The arm 22 penetrates the machining tank 12 and supports the lower guide block 20 in the machining fluid LQ. The arm 22 is installed on the column 11B. The machining tank 12 has a wall portion 12a on the -Y direction side. A long hole that is long in the X direction is formed in the wall portion 12a. The arm 22 extends to the inside of the machining tank 12 through this long hole.

[0028] Note that a seal member is provided in the machining tank 12 to prevent the machining fluid LQ in the machining tank 12 from leaking through the gap between the long hole in the wall portion 12a and the arm 22. The illustration of the seal member is omitted.

[0029] FIG. 2 is a diagram showing the wire electrical discharge machining machine 10 when the machining tank 12 has moved to a position different from that in FIG. 1 in response to the drive of the drive mechanism 14. In FIG. 2, the slider 26 is at the position on the most -Y direction side within the movement range of the slider 26.

[0030] In response to the movement of the machining tank 12, the relative positional relationship between the machining tank 12 and the arm 22 changes. For example, when the machining tank 12 moves in the Y direction, the relative positional relationship in the Y direction between the machining tank 12 and the arm 22 changes.

[0031] In the following description, the relative positional relationship refers to the relative positional relationship in the Y direction between the machining tank 12 and the arm 22 unless otherwise specified.

[0032] In response to the change in the relative positional relationship, the ratio of the portion of the arm 22 located inside the machining tank 12 changes. However, the arm 22 has a first portion 30 and a second portion 32 described below.

[0033] The first part 30 is the portion of the arm 22 that remains within the machining chamber 12 regardless of changes in relative position. The first part 30 is located within the machining chamber 12 when the slider 26 is in its most +Y-direction position within the range of movement of the slider 26 (see also Figure 1). By being located within the machining chamber 12, the first part 30 is immersed in the machining fluid LQ within the machining chamber 12. The first part 30 includes the first end 22a of the arm 22 in the Y-direction. The lower guide block 20 is attached, for example, to the first end 22a.

[0034] The second part 32 is the portion of the arm 22 that is located outside the machining chamber 12 regardless of changes in relative position. The second part 32 is located outside the machining chamber 12 when the slider 26 is in its furthest -Y direction position within the range of movement of the slider 26 (see also Figure 2). The second part 32 includes the second end 22b of the arm 22 in the Y direction. The second end 22b is fixed to the column 11B.

[0035] Figure 3 is a schematic diagram showing the configuration of the wire electrical discharge machining machine 10 related to the arm 22.

[0036] The wire electrical discharge machining machine 10 further comprises a wire pipe 34 and a nozzle communication pipe 36. The wire pipe 34 and the nozzle communication pipe 36 pass through the interior 28 of the arm 22 and are connected to the lower guide block 20.

[0037] The wire electrode 24, which has passed through the lower guide block 20, is inserted into the wire pipe 34. The wire electrode 24 is guided through the wire pipe 34 to a collection box installed outside the processing tank 12. The collection box is not shown in the diagram.

[0038] The nozzle connecting pipe 36 connects the processing fluid tank and the nozzle 20a. The processing fluid tank is a tank that stores the processing fluid LQ outside the processing tank 12. The processing fluid LQ in the processing fluid tank flows through the nozzle connecting pipe 36 toward the nozzle 20a. The diagram of the processing fluid tank is omitted.

[0039] The wire electrical discharge machining machine 10 may further include a pump that forcibly flows the machining fluid LQ in the nozzle communication pipe 36 toward the nozzle 20a. The pump is not shown in the illustration.

[0040] The arm 22 further includes a processing fluid inlet 38, a processing fluid outlet 40, and an air vent 42. Each of the processing fluid inlet 38, processing fluid outlet 40, and air vent 42 is an opening that connects the inside 28 of the arm 22 to the outside.

[0041] The processing fluid inlet 38 is formed in the first portion 30. The arm 22 has a processing fluid inlet 38, which allows the processing fluid LQ from the processing tank 12 to be drawn into the interior 28 of the arm 22 through the processing fluid inlet 38.

[0042] Furthermore, the processing fluid LQ (LQ1) taken in from the processing fluid inlet 38 is separated from the wire electrode 24 inside the wire pipe 34 by the wire pipe 34. In addition, the processing fluid LQ1 is separated from the processing fluid LQ (LQ2) inside the nozzle communication pipe 36 by the nozzle communication pipe 36.

[0043] Preferably, a filter 44 is installed at the processing fluid inlet 38. The filter 44 filters the processing fluid LQ passing through the processing fluid inlet 38. This prevents foreign matter such as sludge mixed in the processing fluid LQ from entering the interior 28 of the arm 22.

[0044] The processing fluid outlet 40 is formed in the second part 32. The processing fluid outlet 40 communicates with the processing fluid inlet 38 via the interior 28 of the arm 22. The processing fluid LQ (LQ1) inside the interior 28 of the arm 22 is discharged from the processing fluid outlet 40.

[0045] The wire pipe 34 may also extend outside the arm 22 through the processing fluid outlet 40. In this case, there is no need to form an opening for guiding the wire electrode 24 outside the arm 22 separately from the processing fluid outlet 40, thus simplifying the shape of the arm 22.

[0046] The air vent 42 is an opening for releasing air A from the inside 28 of the arm 22. The air vent 42 is connected, for example, to an air tube 48 located outside the arm 22 via a joint 46.

[0047] Preferably, the air vent 42 is formed in the second portion 32. This ensures that the air vent 42 is not located inside the processing tank 12, regardless of changes in the relative positional relationship. Therefore, for example, the air tube 48 connected to the air vent 42 is prevented from interfering with the wire electrode 24, the workpiece W, etc., inside the processing tank 12.

[0048] Furthermore, the second portion 32 is outside the range of relative movement of the wall portion 12a of the processing tank 12 with respect to the arm 22. Therefore, the formation of an air vent 42 in the second portion 32 prevents the air tube 48 connected to the air vent 42 from interfering with the wall portion 12a.

[0049] According to this embodiment, the temperature of the part of the arm 22 located inside the processing tank 12 is the same as the temperature of the processing fluid LQ inside the processing tank 12. In addition, the processing fluid LQ from the processing tank 12 is drawn into the interior 28 of the arm 22. The drawn-in processing fluid LQ1 also flows to the part of the interior 28 of the arm 22 located outside the processing tank 12. As a result, the temperature of the part of the arm 22 located outside the processing tank 12 is adjusted to a temperature corresponding to the temperature of the processing fluid LQ1.

[0050] In other words, the entire arm 22 is temperature-controlled according to the temperature of the machining fluid LQ in the machining tank 12. As a result, for example, during electrical discharge machining, the temperature of the entire arm 22 is uniformly adjusted to a temperature corresponding to the temperature of the machining fluid LQ in the machining tank 12.

[0051] By ensuring that the temperature of the entire arm 22 is uniform during electrical discharge machining, even if the proportion of the arm 22 located within the machining chamber 12 changes during electrical discharge machining, the change in the length of the arm 22 is suppressed. By suppressing the change in the length of the arm 22 during electrical discharge machining, machining accuracy is improved.

[0052] Furthermore, according to this embodiment, the processing fluid outlet 40 is formed at the second end 22b of the second portion 32. As a result, the processing fluid LQ1 flows through the inside 28 of the arm 22 to the second end 22b. With the processing fluid LQ1 flowing to the second end 22b, the temperature of the entire second portion 32 is made more uniform. Therefore, changes in the length of the arm 22 are further suppressed.

[0053] Furthermore, according to this embodiment, air A can be removed from the inside 28 of the arm 22 through the air vent 42. By removing air A from the inside 28 of the arm 22, the inside 28 of the arm 22 can be filled with more processing fluid LQ1. As the inside 28 of the arm 22 is filled with more processing fluid LQ1, the overall temperature of the arm 22 becomes more uniform. Therefore, changes in the length of the arm 22 are further suppressed.

[0054] The machining fluid LQ1 is the machining fluid LQ heated by the electrical discharge generated in the machining tank 12. In contrast, the machining fluid LQ2 flowing through the nozzle communication pipe 36 is preferably as cold as possible in order to cool the wire electrode 24 and the workpiece W.

[0055] Based on this, it is preferable that the nozzle communication pipe 36 has high thermal insulation properties. High thermal insulation properties of the nozzle communication pipe 36 can suppress heat exchange between the processing fluid LQ1 flowing inside the arm 22 28 and the processing fluid LQ2 flowing through the nozzle communication pipe 36. This suppresses the heating of the processing fluid LQ2 by the processing fluid LQ1.

[0056] [Differentiation] The following describes modifications according to the above embodiment. However, descriptions that overlap with the above embodiment will be omitted as much as possible in the following description. Elements already described in the above embodiment are denoted by the same reference numerals as in the above embodiment unless otherwise specified.

[0057] (Variation 1) Figure 4A is a configuration diagram of the wire electrical discharge machining machine 101(10) according to Modification 1. However, the illustration of elements already described in the embodiments is omitted as much as possible.

[0058] The wire electrical discharge machining machine 101 has the same components as the wire electrical discharge machining machine 10 (see also Embodiments). However, the wire electrical discharge machining machine 101 includes an arm 221 which is a modified version of the arm 22. The arm 221 differs from the arm 22 in that it further includes a wire discharge port 58, which will be described later.

[0059] Furthermore, the wire electrical discharge machining machine 101 is equipped with a first pipe 50, a first valve 52, a second pipe 54, and a second valve 56. The first pipe 50, the first valve 52, the second pipe 54, and the second valve 56 are located outside the arm 221.

[0060] The first pipe 50 is connected to the processing fluid outlet 40. As a result, the processing fluid LQ inside the arm 221 flows through the processing fluid outlet 40 to the first pipe 50.

[0061] The first valve 52 is provided in the first piping 50. When the first valve 52 is open, the processing fluid LQ that has flowed from the processing fluid inlet 38 into the interior 28 of the arm 221 is discharged from the first piping 50. In Figure 4A, the first valve 52, which is painted white, is in the open state.

[0062] The second pipe 54 is connected to the first pipe 50 between the first valve 52 and the processing fluid outlet 40. The second pipe 54 is a pipe through which fluid FL flows for cleaning the inside 28 of the arm 221 (see Figure 4B). Fluid FL is, for example, clean processing fluid LQ or clean air.

[0063] The second valve 56 is installed in the second piping 54. The second valve 56 is closed while the processing fluid LQ is being discharged from the processing fluid outlet 40. In Figure 4A, the second valve 56, which is blacked out, is in the closed state.

[0064] Here, if the wire pipe 34 is passed through the processing fluid outlet 40 as in the embodiment, the wire pipe 34 extends into the first piping 50. In this case, the opening and closing of the first valve 52 may be obstructed by the wire pipe 34 in the first piping 50. The wire pipe 34 may be removed before closing the first valve 52, but this is time-consuming.

[0065] Based on this, the arm 221 has a wire outlet 58. The wire outlet 58 is an opening formed in the second part 32. The wire outlet 58 is formed in a different location from the processing fluid outlet 40. The wire pipe 34 passes through the wire outlet 58, not the processing fluid outlet 40. As a result, the opening and closing of the first valve 52 is not obstructed by the wire pipe 34. Therefore, it is not necessary to remove the wire pipe 34 in order to close the first valve 52.

[0066] Figure 4B shows the flow of fluid FL when the second valve 56 is open. As with Figure 4A, illustrations of elements already described in the embodiment are omitted as much as possible.

[0067] The second valve 56 is opened when the processing fluid LQ is not discharged from the processing fluid outlet 40. In Figure 4B, the second valve 56, which is painted white, is in the open state.

[0068] When the second valve 56 is opened, the fluid FL flows into the first pipe 50 through the second pipe 54. A pump may be provided in the second pipe 54. This pump forces the fluid FL to flow toward the first pipe 50 while the second valve 56 is open.

[0069] The fluid FL that flows through the first pipe 50 flows through the processing fluid outlet 40 into the interior 28 of the arm 221. The fluid FL that flows into the interior 28 of the arm 221 is discharged from the processing fluid inlet 38 along with dirt and other contaminants present in the interior 28 of the arm 221. This cleans the interior 28 of the arm 221.

[0070] When the second valve 56 is opened, it is preferable that the first valve 52 is closed. This allows the fluid FL to flow more reliably into the interior 28 of the arm 221. In Figure 4B, the first valve 52, which is blacked out, is in the closed position.

[0071] (Modification 2) The processing fluid inlet 38 may be formed in a location other than the lower part of the first portion 30. For example, the processing fluid inlet 38 may be formed in the upper or side part of the first portion 30.

[0072] (A combination of multiple variations) The aforementioned variations may be combined as appropriate, provided that no contradictions arise.

[0073] [Invention obtained from the embodiment] The inventions that can be understood from the above embodiments and modifications are described below.

[0074] One invention relates to a wire electrical discharge machine (10) that processes a workpiece (W) by generating an electrical discharge between a wire electrode (24) and the workpiece (W) in a processing fluid (LQ), comprising: a processing tank (12) for storing the processing fluid and containing the workpiece; a hollow arm (22) through which the wire electrode is inserted to guide the wire electrode, which has passed through the workpiece, out of the processing tank; and a mechanism for changing the relative positional relationship between the processing tank and the arm, at least in the direction of extension of the arm. The wire electrical discharge machine comprises a drive mechanism (14), a processing fluid inlet (38) formed in a first portion (30) of the arm that is located inside the processing tank regardless of the change in the extension direction of the relative positional relationship, and which guides the processing fluid into the interior (28) of the arm, and a processing fluid outlet (40) formed in a second portion (32) of the arm that is located outside the processing tank regardless of the change in the extension direction of the relative positional relationship, and which discharges the processing fluid that has entered through the processing fluid inlet to the outside of the arm.

[0075] As a result, the entire arm is temperature-controlled according to the temperature of the machining fluid in the machining tank, thus suppressing changes in the length of the arm during electrical discharge machining.

[0076] The wire electrical discharge machine may further have an air vent (42) for removing air (A) that has entered the interior of the arm from the processing fluid inlet or the processing fluid outlet. This allows the interior of the arm to be filled with more processing fluid.

[0077] The wire electrical discharge machining machine may further include a filter (44) to prevent sludge from entering the inside of the arm through the machining fluid inlet. This prevents the inside of the arm from being contaminated with sludge.

[0078] The wire electrical discharge machining machine may further include a first pipe (50) through which the machining fluid discharged from the machining fluid outlet flows, a first valve (52) provided in the first pipe, a second pipe (54) connected between the machining fluid outlet and the first valve in the first pipe, through which a fluid (FL) for cleaning the inside of the arm flows toward the first pipe, and a second valve (56) provided in the second pipe. This allows the inside of the arm to be cleaned with the fluid. [Explanation of symbols]

[0079] 10, 101... Wire EDM machine 12... Machining tank 14…Drive mechanism 22, 221…Arms 24...Wire electrode 28...Inside of the arm 30…First part 32…Second part 38...Machining fluid inlet 40...Machining fluid outlet 42...Air vent 44...Filter 50...First piping 52...First valve 54...Second piping 56...Second valve FL…fluid LQ…processing fluid W...Object to be processed

Claims

1. A wire electrical discharge machine that processes a workpiece by generating an electrical discharge between a wire electrode and the workpiece in a processing fluid, A processing tank for storing the processing liquid and containing the object to be processed, A hollow arm through which the wire electrode is inserted, which penetrates the processing tank and guides the wire electrode that has passed through the workpiece to the outside of the processing tank, A drive mechanism that changes the relative positional relationship between the processing tank and the arm, at least in the extending direction of the arm, Of the arm, a first portion located within the processing tank, regardless of the change in the extension direction of the relative positional relationship, is formed and has a processing fluid inlet that guides the processing fluid into the interior of the arm, Of the arm, a second portion located outside the processing tank, regardless of the change in the extension direction of the relative positional relationship, is formed, and a processing fluid outlet is formed to discharge the processing fluid that has entered through the processing fluid inlet to the outside of the arm, It has, A wire electrical discharge machine in which the processing fluid taken in from the processing fluid inlet is separated from the wire electrode inside the arm.

2. A wire electrical discharge machine that processes a workpiece by generating an electrical discharge between a wire electrode and the workpiece in a processing fluid, A processing tank for storing the processing liquid and containing the object to be processed, A hollow arm through which the wire electrode is inserted, which penetrates the processing tank and guides the wire electrode that has passed through the workpiece to the outside of the processing tank, A drive mechanism that changes the relative positional relationship between the processing tank and the arm, at least in the extending direction of the arm, Of the arm, a first portion located within the processing tank, regardless of the change in the extension direction of the relative positional relationship, is formed and has a processing fluid inlet that guides the processing fluid into the interior of the arm, Of the arm, a second portion located outside the processing tank, regardless of the change in the extension direction of the relative positional relationship, is formed, and a processing fluid outlet is formed to discharge the processing fluid that has entered through the processing fluid inlet to the outside of the arm, An air vent for removing air that has entered the interior of the arm from the processing fluid inlet or the processing fluid outlet, A wire electrical discharge machining machine.

3. A wire electrical discharge machine that processes a workpiece by generating an electrical discharge between a wire electrode and a workpiece in a processing fluid, A processing tank for storing the processing liquid and containing the object to be processed, A hollow arm through which the wire electrode is inserted, which penetrates the processing tank and guides the wire electrode that has passed through the workpiece to the outside of the processing tank, A drive mechanism that changes the relative positional relationship between the processing tank and the arm, at least in the extending direction of the arm, Of the arm, a first portion located within the processing tank, regardless of the change in the extension direction of the relative positional relationship, is formed and has a processing fluid inlet that guides the processing fluid into the interior of the arm, Of the arm, a second portion located outside the processing tank, regardless of the change in the extension direction of the relative positional relationship, is formed, and a processing fluid outlet is formed to discharge the processing fluid that has entered through the processing fluid inlet to the outside of the arm, A first pipe through which the processing fluid discharged from the processing fluid outlet flows, A first valve provided in the first piping, A second pipe is connected between the processing fluid outlet and the first valve of the first piping, and through which a fluid for cleaning the inside of the arm flows toward the first piping, A second valve provided in the second piping, A wire electrical discharge machining machine.

4. A wire electrical discharge machine according to any one of claims 1 to 3, A wire electrical discharge machine further comprising a filter to prevent sludge from entering the interior of the arm through the processing fluid inlet.

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