Emmersive wire electric discharge machine

Abstract

To provide an emmersive wire electric discharge machine capable of improving workpiece processing accuracy by making movement of a processing tank precise.SOLUTION: This emmersive wire electric discharge machine comprises: a processing tank 3 configured to be able to oscillate in a longitudinal / lateral direction via an oscillation mechanism 2 connected downward for alignment of discharge processing; a discharge processing mechanism 5 including upper and lower wire heads 52 and 53 having a wire electrode E between and arranged to face each other in the processing tank 3; a processing machine support pipe inserted into the processing tank 3 to support the lower wire head 53 of the discharge processing mechanism 5; and a processing liquid supply pipe 7 for supplying processing liquid L to the processing tank 3. The processing liquid supply pipe 7 is connected to the processing machine support pipe, and supplying of the processing liquid L to the processing tank 3 is carried out from a tip opening 62 of the processing machine support pipe.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a submerged wire electric discharge machine which performs electric discharge machining on a workpiece contained in a machining tank in a machining fluid. [Background technology]

[0002] Generally, immersion wire electric discharge machines (hereinafter referred to as "wire electric discharge machines") are known as electric discharge machines that use a wire electrode to shape a workpiece (hereinafter referred to as "work") immersed in machining fluid into a predetermined shape. In immersion wire electric discharge machines, the workpiece is machined by an electric discharge action generated between the workpiece and the wire electrode. The workpiece is fixed to a workpiece support table installed in the machining tank by a workpiece mounting bracket, and is configured to be movable relative to the wire electrode together with the machining tank. A wire electric discharge machine configured in this way can perform extremely precise machining by moving the workpiece together with the machining tank relative to the wire electrode fixed in the machining tank.

[0003] In wire electric discharge machining, when an electric discharge phenomenon occurs between the workpiece and the wire electrode, the workpiece and the wire electrode are exposed to heat of several thousand degrees, which may cause the wire electrode, which is made of a thin metal wire, to break. For this reason, wire electric discharge machining is performed in a state in which the workpiece and the wire electrode are immersed in machining fluid stored in a machining tank in order to cool the wire electrode. Thus, in wire electric discharge machining, a large amount of machining fluid needs to be stored in the machining tank in order to immerse the workpiece and the wire electrode.

[0004] Patent Document 1 discloses a configuration in which a supply port capable of supplying machining fluid is provided on the side wall of a machining tank that contains a workpiece and machining fluid. In this electric discharge machine, a machining fluid supply pipe is connected to the supply port, making it possible to supply a large amount of machining fluid to the machining tank in a short period of time. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 9-216130 Summary of the Invention [Problem to be solved by the invention]

[0006] According to the configuration disclosed in Patent Document 1, a machining fluid supply pipe that supplies machining fluid is connected to a machining tank that moves integrally with the workpiece, and the machining fluid supply pipe moves in conjunction with the movement of the machining tank. However, there is a risk that the movement of the machining tank will be hindered by the machining fluid supply pipe, thereby reducing the machining accuracy of the workpiece.

[0007] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide an immersion type wire electric discharge machine that can precisely move the machining tank and improve the machining accuracy of the workpiece. [Means for solving the problem]

[0008] The submersible wire electric discharge machine of the present invention has a machining tank that is configured to be swingable vertically and horizontally via a swing mechanism connected below for aligning the electric discharge machining, an electric discharge machining mechanism having upper and lower wire heads arranged opposite each other in the machining tank with a wire electrode stretched between them, a machining machine support pipe inserted into the machining tank to support the lower wire head of the electric discharge machining mechanism, and a machining fluid supply pipe for supplying machining fluid to the machining tank, wherein the machining fluid supply pipe is connected to the machining machine support pipe so that the machining fluid is supplied to the machining tank from an opening at the tip of the machining machine support pipe.

[0009] In another embodiment of the present invention, there is provided an immersion type wire electric discharge machine, wherein the machining fluid supply pipe is fixed to a base end of the machine support pipe which is inserted into the machining tank. Effect of the Invention

[0010] According to the immersion type wire electric discharge machine of the present invention, the wire electric discharge machine has a machining tank configured to be swingable in the vertical and horizontal directions via a swing mechanism connected below for aligning the electric discharge machining, an electric discharge machining mechanism having upper and lower wire heads arranged opposite each other in the machining tank with a wire electrode stretched between them, a machining machine support pipe inserted into the machining tank to support the lower wire head of the electric discharge machining mechanism, and a machining fluid supply pipe for supplying machining fluid to the machining tank, in which the machining fluid supply pipe is connected to the machining machine support pipe so that the machining fluid is supplied to the machining tank from the opening at the tip of the machining machine support pipe, the machining tank can be moved independently of the machining fluid supply pipe. In other words, by configuring the machining tank to be movable without being hindered by the machining fluid supply pipe, the accuracy of movement of the machining tank during electric discharge machining can be improved, thereby improving the machining accuracy of the workpiece.

[0011] According to another embodiment of the present invention, the machining fluid supply pipe is fixed to the base end of the machine support pipe inserted into the machining tank, so machining fluid can be supplied to the machining tank without changing the diameter of the machine support pipe. In other words, the outer diameter of the machine support pipe inserted into the machining tank can be made approximately the same as in the past, so there is a low probability that the movement of the machining fluid that moves with the machining tank will be hindered by the machine support pipe, and the movement accuracy of the machining tank can be improved. This improves the machining accuracy of the workpiece. [Brief description of the drawings]

[0012] [Figure 1] 1 is a perspective view of a wire electric discharge machine according to an embodiment of the present invention; [Diagram 2] 1 is a side view, partially in section, of a wire electric discharge machine according to an embodiment of the present invention; [Diagram 3] 1 is a front view, partially in section, of a wire electric discharge machine according to an embodiment of the present invention; [Figure 4] FIG. 3 is an enlarged cross-sectional view of a portion of FIG. 2. [Diagram 5]3 is a view taken along line AA in FIG. 2. [Figure 6] 1 is a rear view of a wire electric discharge machine according to an embodiment of the present invention, with the machine body omitted. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention relates to an immersion type wire electric discharge machine that performs electric discharge machining on a workpiece contained in a machining tank in machining fluid, and by making it possible to supply machining fluid to the machining tank via a machine support pipe that is supported in an independent manner from the machining tank, the accuracy of movement of the machining tank is improved, thereby improving the accuracy of electric discharge machining of the workpiece. Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0014] The overall configuration of the wire electric discharge machine M according to this embodiment will be described with reference to FIGS. 1 to 6. FIG. 1 is a perspective view showing an overall image of the wire electric discharge machine M. FIG. 2 is a side view of the wire electric discharge machine M, in which some parts, such as the machining tank 3, the support table 4, the shielding plate 34, and the seal portion 35, are shown in cross-section. FIG. 3 is a front view of the wire electric discharge machine M, in which some parts, such as the machining tank 3 and the support table 4, are shown in cross-section. FIG. 4 is an enlarged cross-sectional view showing the vicinity of the lower arm portion 6 in FIG. 2, and FIG. 5 is an arrow view seen from the direction of line AA in FIG. 2. FIG. 6 is a rear view of the wire electric discharge machine M with the column 11 omitted. In the description of this embodiment, the direction indicated by the double arrow in FIG. 2 is the Y-axis direction, and the direction indicated by the double arrow in FIG. 3 is the X-axis direction. That is, the X-axis direction refers to the left-right direction when the wire electric discharge machine M is viewed from the front, and the Y-axis direction refers to the front-rear direction of the wire electric discharge machine M.

[0015] 1, the wire electric discharge machine M is a so-called immersion type wire electric discharge machine that machines a workpiece with electric discharge energy generated by applying a gap voltage between a wire electrode E and a workpiece while the workpiece is immersed in machining fluid L. The wire electric discharge machine M includes a machine body 1 having a base 10 such as a machine stand provided on an installation surface and a column 11, a swing mechanism 2 mounted on the base 10 of the machine body 1 so as to be movable in the X-axis direction and the Y-axis direction, a machining tank 3 mounted and fixed on the swing mechanism 2, a support table 4 fixed to the inner bottom surface of the machining tank 3 by fastening means such as bolts, an electric discharge machining mechanism 5 supported by the column 11 of the machine body 1 and fixing the wire electrode E at a predetermined position in the machining tank 3 while applying electric current to the wire electrode E, a lower arm section 6 as a machine support pipe extending from the column 11 of the machine body 1 to the machining tank 3 and having a tip portion inserted into the machining tank 3, and a machining fluid supply pipe 7 connected to the lower arm section 6 and supplying machining fluid L to the machining tank 3.

[0016] The processing machine body 1 comprises a base 10 placed on a mounting surface and a column 11 erected behind the base 10. The base 10 is formed in a box shape, and a pair of Y-axis guide rails 12 and a Y-axis moving means are arranged on the upper surface thereof. The Y-axis guide rails 12 are substantially rectangular in cross section and are laid along the left and right sides of the base 10 from near the front end to near the rear end of the base 10. The Y-axis moving means is provided in the substantially central portion of the pair of left and right Y-axis guide rails 12, and has a driving motor and a screw shaft for transmitting the rotation of the motor. The screw shaft is composed of a ball screw that converts the rotational motion of the motor into linear motion.

[0017] The column 11 has a rectangular column-shaped column body 13 erected on a support surface behind the base 10. The column body 13 has an arm fixing hole 14 that is circular in front view at the top and bottom center of the front side surface. The column body 13 has an upper arm section 50 connected to its top, and a lower arm section 6 connected to the arm fixing hole 14. The lower arm section 6 is supported with its central axis in the pipe shape aligned along the front-rear direction, penetrating the front wall section of the column body 13 that forms the arm fixing hole 14, and its rear end section positioned inside the column body 13. Each arm section is supported by the column body 13 in the form of a cantilever.

[0018] The rocking mechanism 2 is composed of a Y-axis table 20 that is horizontally movable in the Y-axis direction on the upper surface of the base 10, and an X-axis table 21 that is horizontally movable in the X-axis direction on the upper surface of the Y-axis table 20.

[0019] The Y-axis table 20 has a Y-axis table main body 22 formed into a rectangular plate of a certain thickness with its longer side in the X-axis direction, Y-axis slide guides 23 provided on the underside of the Y-axis table main body 22 near each corner, a pair of X-axis guide rails 24 extending in the X-axis direction along the front and rear side edges of the Y-axis table main body 22 on the upper surface of the Y-axis table main body 22, and shielding plate support parts 29 connected to the left and right sides of the rear end part of the Y-axis table main body 22.

[0020] The Y-axis table body 22 has a Y-axis movement hole 25 formed in the center of the front and rear sides, penetrating from the front to the rear. The Y-axis table body 22 has the Y-axis movement hole 25 engaged with a screw shaft of a Y-axis movement means.

[0021] The Y-axis slide guide 23 has a recess provided in the center of the lower surface from front to back. The Y-axis guide rail 12 is fitted into the recess of the Y-axis slide guide 23. In other words, the Y-axis table main body 22 is placed on the Y-axis guide rail 12 via the recess of the Y-axis slide guide 23.

[0022] The X-axis guide rail 24 is formed in a substantially rectangular shape in cross section, and is laid along the front and rear sides of the upper surface of the Y-axis table main body 22 from near the left end to near the right end of the Y-axis table main body 22. In addition, the X-axis moving means is disposed in the vicinity of either the left or right end of the Y-axis table main body 22 in the X-axis direction, approximately in the center between the pair of X-axis guide rails 24.

[0023] The X-axis moving means is composed of a motor for rotation and a screw shaft for transmitting the rotational force of the motor. The screw shaft extends approximately parallel to the X-axis guide rail 24. The screw shaft is composed of a ball screw that converts the rotational motion of the motor into linear motion.

[0024] The shielding plate support part 29 is configured of a plate body having a square shape when viewed from the front, and extends upward from the Y-axis table main body 22. The shielding plate support part 29 has a shielding plate 34 fixed to the vicinity of its upper end by a fastening means such as a screw. In other words, the shielding plate support part 29 fixes the shielding plate 34 to the Y-axis table main body 22.

[0025] The X-axis table 21 has a plate-like X-axis table main body 26 having a certain thickness and formed in a square shape in a plan view, and X-axis slide guides 27 provided on the underside near each corner of the X-axis table main body 26. The X-axis table main body 26 has an X-axis movement hole 28 formed in the center of the X-axis side surface along the X-axis direction, penetrating the X-axis direction. The X-axis table main body 26 is moved along the X-axis direction in conjunction with the rotation of the screw shaft by engaging the X-axis movement hole 28 with the screw shaft of the X-axis moving means. At this time, the X-axis slide guide 27 slides on the pair of X-axis guide rails 24.

[0026] As described above, the wire electric discharge machine M in this embodiment is equipped with the Y-axis table 20 and the X-axis table 21 as the oscillation mechanism 2, and the machining tank 3 mounted and fixed on the X-axis table 21 can be moved arbitrarily in the X-axis direction or the Y-axis direction by the Y-axis moving means mounted and fixed on the base 10 of the machine body 1 and the X-axis moving means mounted and fixed on the Y-axis table 20. The movement direction and amount of movement of the oscillation mechanism 2 are controlled by a control unit (not shown) by specifying numerical values, etc.

[0027] The processing tank 3 is formed in the shape of a rectangular box with an open top and a bottom, and has a horizontal bottom surface portion 31 and four vertical side wall surface portions 32. The bottom surface portion 31 of the processing tank 3 is placed on the X-axis table 21, and the processing tank 3 is configured to be movable integrally with the X-axis table 21. The side wall surface portion 32 constituting the rear surface of the processing tank 3 has a long hole 33 drilled in an elliptical shape with the X-axis direction as the longitudinal direction near the lower end portion at the center in the left-right direction, and a seal portion 35 that supports a shielding plate 34 provided to cover the long hole 33 from the outside of the side wall surface portion 32 so as to be in sliding contact with the outer surface of the side wall surface portion 32.

[0028] The elongated hole 33 is formed to have a vertical width slightly larger than the vertical width of the lower arm portion 6. In other words, the lower arm portion 6 is inserted into the processing tank 3 without contacting the opening edge of the elongated hole 33.

[0029] As shown in Figures 4 and 6, the sealing portion 35 is composed of a shield plate support portion 36 provided along the upper and lower edges of the long hole 33, and a sliding contact member 37 that slidably supports the shield plate 34 covering the long hole 33 against the hydraulic pressure of the machining fluid L contained in the machining tank 3.

[0030] The shielding plate support portion 36 is composed of a plurality of flat plate-like protruding portions 36a arranged along the upper and lower edges of the long hole 33 and protruding rearward, and a similarly flat plate-like pressing plate portion 36b connected to the tip of the protruding portion 36a in a manner perpendicular to the protruding portion 36a. That is, the shielding plate support portion 36 is formed into a substantially "L" shape by the protruding portion 36a and the pressing plate portion 36b in a side view. In this embodiment, the shielding plate support portion 36 is provided at three locations at predetermined intervals in the left-right direction along the upper and lower edges of the long hole 33.

[0031] The sliding member 37 is provided at the tip of the pressing plate portion 36b constituting the shield plate support portion 36. That is, the sliding member 37 is provided on the side surface of the upper shield plate support portion 36 on the side wall surface portion 32 side (front side) near the lower end of the pressing plate portion 36b, and on the side surface of the lower pressing plate portion 36b on the side wall surface portion 32 side near the upper end of the pressing plate portion 36b. The sliding member 37 has an uneven surface portion 38 consisting of convex portions and concave portions extending in the sliding direction on the contact surface with the shield plate 34. The uneven surface portion 38 of the sliding member 37 reduces the sliding resistance against the shield plate 34 and ensures the rigidity to support the shield plate 34 against the hydraulic pressure of the machining fluid L.

[0032] The shielding plate 34 is supported and fixed by shielding plate supports 29 connected to the left and right rear ends of the Y-axis table 20. When viewed from the front, the shielding plate 34 is a rectangular plate whose longitudinal direction is the X-axis direction, and has an insertion hole 34a in the center for inserting the lower arm unit 6. The insertion hole 34a is a circular hole formed to be slightly larger in diameter than the lower arm unit 6. The insertion hole 34a has a diameter approximately equal to the vertical width of the long hole 33. A bellows 39 is connected to the edge of the insertion hole 34a provided in the shielding plate 34.

[0033] Bellows 39 is fixed with the outer circumferential surface of its base end in contact with the inner circumferential surface of insertion hole 34a over its entire circumference, and with the inner circumferential surface of its tip end in contact with the outer circumferential edge of the tip side of lower arm section 6 over its entire circumference. In other words, bellows 39 is mounted across shielding plate 34 and lower arm body 60 of lower arm section 6, covers the outer circumferential surface of lower arm body 60 inserted into machining tank 3, and keeps the outer circumferential surface of lower arm body 60 out of contact with machining fluid L.

[0034] A support table 4 for supporting and fixing a workpiece in the machining tank 3 is fixed to the bottom surface 31 of the machining tank 3 by a fixing means such as a bolt. The support table 4 is composed of a base portion 40 for fixing the workpiece and a leg portion 41 for supporting the base portion 40 at a predetermined height in the machining tank 3. The base portion 40 is formed in a rectangular plate shape, and has a rectangular opening 42 drilled in the center in a plan view. A fixing jig is fixed to the base portion 40 near the opening 42. The workpiece is fixed to the base portion 40 near the opening 42 by a fastening means such as a bolt via the fixing jig. At this time, the workpiece is fixed in a manner protruding into the opening 42. In addition, a lead wire is connected to the base portion 40, one end of which is connected to a power source that generates a predetermined voltage during electric discharge machining. In this embodiment, the base portion 40 is connected to the negative side of the power source by a lead wire.

[0035] As described above, the workpiece and the support table 4 are fixed together via a fixing jig, and the support table 4 and the machining tank 3 are fixed together via the legs 41 of the support table 4, so that the workpiece can move together with the machining tank 3. In other words, the amount of movement of the machining tank 3 by the swing mechanism 2 and the amount of movement of the workpiece are the same, and the amount of movement of the workpiece can be precisely controlled simply by numerically controlling the swing mechanism 2.

[0036] An electric discharge machining mechanism 5 is connected to the column body 13 of the machining device body 1. The electric discharge machining mechanism 5 has an upper arm section 50 extending forward in the Y-axis direction from the upper end of the column body 13, a head section 51 vertically attached to the tip of the upper arm section 50, an upper wire head 52 attached to the lower end of the head section 51, a lower wire head 53 connected to the tip of the lower arm section 6 extending from the arm fixing hole section 14 of the column body 13 toward the machining tank 3, and a wire electrode E stretched between the upper wire head 52 and the lower wire head 53.

[0037] The upper arm section 50 extends from the upper end of the column body 13 to an upper position near the rear end of the base section 40 installed in the machining tank 3. The upper arm section 50 is supported in the form of a cantilever at the upper end of the column body 13. A head section 51 is suspended from the tip of the upper arm section 50. The head section 51 has an automatic wire supply device that supplies a wire electrode E used during electric discharge machining, and an upper wire head 52 connected to the lower end of the head section 51.

[0038] The upper wire head 52 incorporates a die guide, a jet nozzle, an electrical supply, etc., as in the conventional case. That is, the upper wire head 52 can send out the wire electrode E supplied from an automatic wire feeder to the lower wire head 53 through a wire feed port of the die guide. The wire electrode E is connected to an electrical supply having one end connected to a power source that generates a predetermined voltage during electric discharge machining within the upper wire head 52. The wire electrode E is connected to the anode side of the power source by the electrical supply.

[0039] The upper jet nozzle is provided near the wire outlet of the die guide, with its outlet oriented along the wire electrode E.

[0040] The lower wire head 53 is disposed below the base portion 40 of the support table 4, facing the upper wire head 52. The lower wire head 53 incorporates a die guide, a jet nozzle, a power supply, a pulley for guiding the wire electrode E after discharge to the wire guide pipe 63, and the like. The lower wire head 53 receives the wire electrode E sent out from the upper wire head 52 through a wire receiving port of the die guide. The wire electrode E is connected to a power supply in the lower wire head 53. One end of the power supply is connected to a power source that generates a predetermined voltage during electric discharge machining. The power supply provided in the lower wire head 53 has the same potential as the power supply provided in the upper wire head 52, and is connected to the anode side of the power source like the upper wire head 52.

[0041] The wire electrode E is a thin metal wire, and is stretched with a constant tension between the upper wire head 52 and the lower wire head 53. The wire electrode E enters the wire receiving port of the lower wire head 53 from the wire outlet port of the upper wire head 52, is guided to the lower arm 6 via the pulley, and is sent out from the other end of the lower arm 6 to the outside of the processing tank 3. The wire electrode E is sent out to the lower arm 6 by the pulley without being deflected within the lower wire head 53.

[0042] The lower arm portion 6 is supported and fixed in a cantilever manner in an arm fixing hole portion 14 provided in the column body 13. The lower arm portion 6 has a hollow lower arm body 60 extending along the Y-axis direction from the arm fixing hole portion 14, a closing plate 61 that closes the base end portion of the lower arm body 60, and a wire guide pipe 63 and a jet nozzle connection pipe 64 housed in the lower arm body 60.

[0043] The lower arm body 60 is hollow with a peripheral wall portion forming a cylindrical inner peripheral surface 60a, and forms a flow path portion 60b for water to flow inside. The inner diameter, which is the flow path diameter of the inner peripheral surface 60a of the lower arm body 60, is approximately constant or has a constant inner diameter throughout the entire lower arm body 60 as viewed in the axial direction. The lower arm body 60 has a tip portion inserted into the processing tank 3 through the insertion hole portion 34a provided in the shielding plate 34 and the long hole 33 of the side wall surface portion 32. The outer diameter of the lower arm body 60 is formed slightly smaller than the inner diameter of the long hole 33 and the insertion hole portion 34a. In the processing tank 3, the lower arm body 60 extends to a position below the opening 42 of the support base 4. That is, the lower arm body 60 extends to a position where the upper wire head 52 connected to the lower end of the head portion 51 and the lower wire head 53 connected to the tip portion of the lower arm body 60 face each other. The lower arm body 60 has a tip opening 62 that communicates with the inside of the processing tank 3 and the flow path portion 60b, and the lower wire head 53 is connected to it so as to close a part of the tip opening 62. The tip opening 62 is an opening on the front side of the pipe-shaped lower arm body 60, and opens the flow path portion 60b facing the processing tank 3.

[0044] The closure plate 61 has four circular holes: a wire guide hole 61a for sending the wire electrode E used in electric discharge machining to the outside of the machining tank 3; a lower arm cooling hole 61b for supplying machining fluid L into the lower arm section 6; a jet nozzle connection hole 61c for supplying machining fluid L to the jet nozzle provided on the lower wire head 53; and a fluid supply hole 61d for supplying machining fluid L to the machining tank 3.

[0045] The wire guide hole 61a is provided in the central lower part of the closure plate 61 when viewed in the axial direction of the lower arm body 60. The rear end of a wire guide pipe 63 arranged in the lower arm body 60 is fitted into the wire guide hole 61a. The wire guide pipe 63 is provided with the central axial direction as the front-rear direction, and the internal space is used as a passage for wiring the wire electrode E. The base end of the wire guide pipe 63 is supported by the closure plate 61 through the wire guide hole 61a, and the tip end is connected to the lower wire head 53. That is, the wire guide pipe 63 is supported by the closure plate 61 in a cantilever manner. The inner peripheral surface 60a of the lower arm body 60 and the outer peripheral surface of the wire guide pipe 63 are provided in a non-contact manner.

[0046] The lower arm internal cooling hole 61b is provided at the central left part (right side in FIG. 5) of the closure plate 61 when viewed in the axial direction of the lower arm main body 60. A liquid supply hose 65 equipped with a liquid feed pump capable of supplying machining liquid L is connected to the lower arm internal cooling hole 61b on the upstream side of the lower arm main body 60. The liquid supply hose 65 constantly supplies machining liquid L to the flow path portion 60b of the lower arm main body 60 during electric discharge machining.

[0047] The jet nozzle connection hole 61c is provided in the center right part (left side in FIG. 5) of the closure plate 61 when viewed in the axial direction of the lower arm body 60. The rear end part of the jet nozzle connection pipe 64 arranged in the lower arm body 60 is fitted into the jet nozzle connection hole 61c. The jet nozzle connection pipe 64 is provided with the central axis direction as the front-rear direction, and the internal space is used as a passage for supplying machining liquid to the jet nozzle of the lower wire head 53. The jet nozzle connection pipe 64 is supported at its base end by the closure plate 61 through the jet nozzle connection hole 61c, and is connected at its tip end to the lower wire head 53. That is, the jet nozzle connection pipe 64 is supported by the closure plate 61 in a cantilever manner. The wire guide pipe 63 is provided in the lower arm body 60 in a manner not in contact with the inner peripheral surface 60a of the lower arm body 60.

[0048] The liquid supply hole 61d is provided at the center upper part of the closing plate 61 when viewed in the axial direction of the lower arm body 60. The liquid supply hole 61d is formed to have a larger diameter than the other holes (wire guide hole 61a, lower arm cooling hole 61b, and jet nozzle connection hole 61c) provided in the closing plate 61. The liquid supply hole 61d is connected to the machining liquid supply pipe 7 on the upstream side of the lower arm body 60. The liquid supply hole 61d is provided with an opening / closing valve that controls the communication state between the flow path portion 60b of the lower arm body 60 and the machining liquid supply pipe 7. The opening / closing valve is linked to the control unit, and opens to open the flow path when the machining liquid L is supplied to the machining tank 3 through the machining liquid supply pipe 7, and closes to close the flow path when a predetermined amount of machining liquid L is stored in the machining tank 3. The opening / closing valve is always closed during electric discharge machining. Whether or not a predetermined amount of machining liquid L has been stored in the machining tank 3 is detected by a sensor (not shown) provided on the upper wire head 52.

[0049] The lower wire head 53 is connected to the tip of the lower arm section 6 formed in this manner so as to partially close the tip opening 62 of the lower arm section 6. The lower wire head 53 is connected and fixed so as to close the central upper part of the tip opening 62 of the lower arm body 60. That is, the machining fluid L supplied to the flow path section 60b of the lower arm body 60 via the lower arm cooling hole section 61b and the fluid supply hole section 61d is supplied from the lower part of the tip opening 62 into the machining tank 3. The black arrows shown in FIG. 4 indicate the flow of water in the lower arm body 60, the jet nozzle connection pipe 64, and the machining fluid supply pipe 7.

[0050] According to the wire electric discharge machine M of this embodiment as described above, the machining tank 3 can be moved without contacting the machining liquid supply pipe 7 by connecting the machining liquid supply pipe 7 for supplying the machining liquid L to the lower arm section 6 as a machining support pipe inserted into the machining tank 3 from the long hole 33 provided in the rear side wall surface section 32 of the machining tank 3, and supplying the machining liquid L from the tip opening 62 of the lower arm section 6. In other words, the piping configuration for supplying the machining liquid to the machining tank 3 does not follow the machining tank 3 or interfere with other configurations as the machining tank 3 moves, so that the piping configuration can be prevented from acting on the moving machining tank 3. As a result, the machining tank 3 can move as set by the swing mechanism 2, and the machining accuracy of the workpiece moving together with the machining tank 3 can be improved.

[0051] Furthermore, in the wire electric discharge machine M according to this embodiment, since the machining fluid supply pipe 7 is fixed to the fluid supply hole 61d of the closure plate 61 provided at the base end of the lower arm portion 6 inserted into the machining tank 3, the machining fluid L can be supplied into the machining tank 3 without changing the diameter of the lower arm portion 6. In other words, since the outer diameter of the lower arm portion 6 inserted into the machining tank 3 can be made approximately the same as the conventional diameter, it is possible to reduce as much as possible the likelihood that the lower arm portion 6 will become a resistance to the machining fluid L moving together with the machining tank 3. This allows the machining tank 3 to move more precisely, improving the machining accuracy of the workpiece.

[0052] Furthermore, in the wire electric discharge machine M according to this embodiment, the elongated hole 33 provided in the side wall surface portion 32 of the machining tank 3 is closed with the shielding plate 34, the shielding plate 34 is supported at a predetermined height by the shielding plate support portion 29 fixed to the Y-axis table 20, and the shielding plate 34 is supported by the uneven surface portion 38 of the sliding member 37 so as to be able to close the elongated hole 33 against the hydraulic pressure of the machining fluid L attempting to leak from the elongated hole 33, thereby reducing as much as possible the effects that act as factors impeding movement of the machining tank 3 in the X direction. This prevents leakage of the machining fluid L from the machining tank 3 and makes it possible to precisely move the machining tank 3, thereby improving the machining accuracy of the workpiece.

[0053] Although one embodiment of the present invention has been described, the above description is merely an example of the present invention, and the present invention is not limited to the above-described embodiment. Therefore, even if the embodiment is different from the above-described embodiment, various modifications can be made depending on the design, etc., as long as they do not deviate from the technical concept of the present invention. [Explanation of symbols]

[0054] 1 Processing machine body 2. Swing mechanism 3 Processing tank 4 Support stand 5 Electric discharge machining mechanism 6 Lower arm 7 Machining fluid supply pipe 52 Upper Wire Head 53 Lower Wire Head 62 Tip opening E Wire Electrode M Wire EDM Machine

Claims

1. a machining tank configured to be swingable in the vertical and horizontal directions via a swing mechanism connected below for alignment of the electric discharge machining; an electric discharge machining mechanism having upper and lower wire heads disposed opposite to each other in the machining tank and with a wire electrode stretched between them; a machining machine support pipe inserted into the machining tank to support the lower wire head of the electric discharge machining mechanism; a machining fluid supply pipe for supplying a machining fluid to the machining tank; In a submerged wire electric discharge machine having a machining fluid supply pipe connected to the machine support pipe, and the machining fluid is supplied to the machining tank from an opening at the tip of the machine support pipe.

2. 2. The immersion type wire electric discharge machine according to claim 1, wherein the machining fluid supply pipe is fixed to a base end of the machine support pipe inserted into the machining tank.

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