JP2011025345A - Electric discharge machining method of pore and device used for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric discharge machining method for making a pore on a shape machining part using a pipe electrode capable of reducing cost of a machining electrode, eliminating need of replacement of the machining electrode while one product is manufactured, and reducing total machining time, and also to provide a device used for the same. <P>SOLUTION: The electric discharge machining method uses the pipe electrode in water, relatively position-controls a three-dimensional position in the XYZ-axis direction of the electrode and a workpiece under control of a control device, and carries out shaped hole machining on the different cross-sectional shape part of the workpiece. Whether a space between the electrode and the workpiece is in a non-electric discharge state or an electric discharge state is determined during electric discharge machining along a shape machining path in which the electrode is programmed. When it is in the electric discharge state, automatic correction of cutting amount in a Z-axis direction considering electrode consumption amount is carried out to the programmed electric discharge machining path, and when it is in the non-electric discharge state, the automatic correction of the cutting amount in the Z-axis direction considering the electrode consumption amount is not carried out to the programmed electric discharge machining path. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

    The present invention relates to a fine hole electric discharge machining method and apparatus, and more particularly, to use a pipe electrode in water, and relative to the three-dimensional position of the machining electrode and workpiece in the XYZ-axis direction under the control of a control device. In particular, the present invention relates to a fine hole electric discharge machining method and apparatus for performing electric discharge machining of a shape hole of the workpiece by controlling the position.

  For example, as an electric discharge machining method for drilling a complicated shape in a workpiece, after machining a small hole with a small machining area with a rod-shaped electrode, machining a portion with a large machining area with a general die-cutting electrode There is a method (for example, Patent Document 1).

JP 2008-018499 A

  However, the method described in the above-mentioned document is an electric discharge machining method having a shape hole having a portion whose machining area greatly changes with respect to the machining area of the narrow hole portion, and the machining of the narrow hole portion having a small machining area is performed in a rod shape. After machining with an electrode, the part with a large machining area is machined with a general die-sculpting electrode, and an expensive general die-sculpting electrode is required, and one total die The limit of the number of holes that can be machined with the engraved electrode is about 1 to 3.

  Therefore, when processing a workpiece having a large number of shape processing portions, a large number of machining electrodes for total die-sculpture are required to manufacture one product, which increases the processing cost. In addition, since the frequency of electrode replacement during the production of a single product increases, it is inevitable that the total processing time is increased. In addition, the electrode for general sculpting has the characteristic that the processing speed cannot be increased due to poor discharge of processing waste generated during processing, which also increases the processing cost by increasing the total processing time. Yes.

  The present invention has been made to solve the above-described problems. The object of the present invention is that the machining electrode is inexpensive and does not require replacement of the machining electrode during the production of a single product, thereby reducing the total machining time. It is an object of the present invention to provide a method and apparatus for fine hole electric discharge machining of a shape machining portion using a pipe electrode that can be shortened.

  The electric discharge machining method according to claim 1, as means for solving the above-described problem, uses a pipe electrode in water, and relatively controls the three-dimensional positions of the electrode and the workpiece in the XYZ-axis direction under the control of a control device. In the electric discharge machining method for performing shape hole machining of cross-sectional shapes having different shapes of the workpiece by controlling the position of the workpiece, the electrode and the workpiece are subjected to electric discharge machining along the programmed shape machining path. It is determined whether there is no discharge state or discharge state between the workpiece, and if it is in the discharge state, the Z-axis direction cut in consideration of the electrode consumption amount is taken into the programmed electric discharge machining path. Automatic correction is performed, and when there is no discharge, automatic correction of cutting in the Z-axis direction in consideration of electrode consumption is not performed on the programmed electric discharge machining path.

  The fine hole electric discharge machining method according to claim 2 is the fine hole electric discharge machining method according to claim 1, wherein in the cross-sectional shape of the shape hole by the XY plane, the shape machining path in the Y-axis direction of the shape machining path. When the length is less than ½ of the electrode diameter, the linear shape machining path in the X-axis direction and the cutting process in the Z-axis direction are performed, and the length of the shape machining path in the Y-axis direction is 1 of the electrode diameter. / 2 or more and less than the electrode diameter, a U-shaped machining path consisting of an X-axis direction and a Y-axis direction and a cutting process in the Z-axis direction are performed, and the length of the shaping path in the Y-axis direction is When the diameter is equal to or larger than the electrode diameter, a square-shaped machining path and cutting in the Z-axis direction are performed.

  The thin hole electric discharge machining apparatus according to claim 3 uses a pipe electrode in water, and relatively controls the position of the three-dimensional position of the electrode and the workpiece in the XYZ axis direction under the control of the control device. In the electric discharge machining apparatus for performing the shape hole machining of the cross-sectional shape portions having different shapes of the workpiece, the electrode is interposed between the electrode and the workpiece during the electric discharge machining along the programmed shape machining path. Is in a no-discharge state or in a discharge state, and if it is in a discharge state, it performs automatic correction of notch in the Z-axis direction in consideration of an electrode consumption amount for the programmed electric discharge machining path, In the non-discharge state, automatic correction of the cut in the Z-axis direction in consideration of the electrode consumption amount is not performed on the programmed electric discharge machining path.

  The fine hole electric discharge machining apparatus according to claim 4 is the fine hole electric discharge machining apparatus according to claim 3, wherein the shape machining path in the Y-axis direction of the shape machining path in a cross-sectional shape of the shape hole along the XY plane. When the length is less than ½ of the electrode diameter, the linear shape machining path in the X-axis direction and the cutting process in the Z-axis direction are performed, and the length of the shape machining path in the Y-axis direction is 1 of the electrode diameter. If the electrode diameter is greater than or equal to 2 or less than the electrode diameter, a U-shaped machining path composed of the X-axis direction and the Y-axis direction and a cutting process in the Z-axis direction are performed. When the diameter is greater than or equal to the diameter, a square-shaped machining path and a cutting process in the Z-axis direction are performed.

  According to the thin hole electric discharge machining method and apparatus of the present invention, the machining of the shape hole and the machining of the through hole are carried out with the same electrode, so that the electrode cost is low, and there are many without replacing the machining electrode. Therefore, the machining cost can be reduced. Also, the shape machining program consisting of the X-axis linear machining path, the U-shaped machining path, and the B-shaped machining path is used for the shape machining of the shape hole portion whose cross-sectional shape is open. As a result, the processing efficiency can be improved. Further, since the same shape machining program can be used to perform the shape hole machining of the cross-sectional shape portions having different shapes such as the turbine blade, it becomes easy to create a machining program.

Explanatory drawing (front view) of the fine hole electric discharge machining apparatus which concerns on this invention. Explanatory drawing at the time of shape hole processing by a pipe electrode. Explanatory drawing of the electrode holder 39. FIG. Explanatory drawing of the chuck | zipper which mounts the electrode holder 39. FIG. An example of the workpiece | work which has a pyramid-shaped hole in the fine hole upper part penetrated diagonally with respect to a flat surface. FIG. 6 is a top view of FIG. 5. The left view of FIG. Explanatory drawing of the shape process path | route in the case of shape-processing to a pyramid-shaped shape hole. The figure which shows the relationship between the program path | route at the time of electric discharge machining in the shape machining path | route of the X-axis direction of the process area | region A part of FIG. 8, and the electrode consumption amount E at the time of electric discharge machining. Explanatory drawing of the shape process path | route in the case of performing the shape process by the electric discharge machining method of this invention. Illustration of a turbine blade T _B with multiple holes having a funnel-shaped portion small hole top. CC sectional drawing of FIG. DD sectional drawing of FIG.

    Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a 6-axis control (X, Y, W, Z, A, B) fine hole electric discharge machining apparatus according to the present invention. Referring now to FIG. 1, on comprehensively shown small hole electric discharge machining apparatus 1 of the base 3, the Y-axis direction movable positioning Y-axis by the driving means and the Y-axis drive motor M _Y (not shown) A table 5 is provided.

  A tray 7 is integrally fixed to the Y-axis table 5, and a stone surface plate 9 that is an insulator is provided on the plate 7, and an L-shaped bracket member 11 is integrally formed on the stone surface plate 9. Is provided.

  On the bracket member 11 is mounted a processing tank 15 for containing a processing liquid 13 such as pure water having a low electrical conductivity, and tiltable for fixing the workpiece W in the processing tank 15. A known turntable device 17 is provided (for example, JP 2002-307248 A).

  The turntable device 17 described above has an A axis centering on an axis parallel to the Z axis (vertical direction in FIG. 1) and a center axis B orthogonal to the A axis (parallel to the Y axis) B. And an axis (tilt axis).

  The B-axis rotation shaft 19 serving as the B-axis drive unit described above extends upward from the horizontal bottom 11a of the L-shaped bracket member 11 along the rear wall (right side in FIG. 1) of the processing tank 15. It is rotatably supported on the mounting portion 11b. The B-axis rotation shaft 19 is provided so as to extend through the rear side wall surface of the processing tank 15 to a substantially central portion inside the processing tank 15.

  A turntable 21 is rotatably attached to the upper left end of the B-axis rotation shaft 19 via a speed reducer (not shown). The B-axis rotary shaft 19 is rotated by a B-axis drive motor (not shown) provided outside the processing tank 15, and the turntable 21 is rotated along the axis of the B-axis rotary shaft 19. It is provided so that it can be rotationally driven by an A-axis drive motor (not shown) through a “blind hole” (not shown) opened outside.

  An annular energization ring (not shown) is provided on the back surface of the turntable 21, and the turntable 21 is connected to a discharge power source (not shown) via the energization ring.

  In the above configuration, if the A-axis drive motor (not shown) is appropriately rotated under the control of the control device (not shown), the turntable 21 can be rotated about the A-axis by an appropriate angle.

Similarly, if the B-axis drive motor (not shown) is appropriately rotated forward or reversely, the turntable 21 can be tilted clockwise or counterclockwise about the B-axis. . Further, by rotationally driving the Y axis drive motor M _Y appropriately, it is possible to position the turntable 21 at an arbitrary position in the Y-axis direction.

  On the base 3 behind the processing tank 15 (right side in FIG. 1), a pair of support columns 25 (a, b) erected on the left and right as viewed from the front side (left side in FIG. 1). In addition, a portal frame made of a beam member 27 suspended horizontally is provided above the pair of support columns 25 (a, b).

The beam member 27 of the portal frame is provided with an X-axis guide rail (not shown) protected by the bellows 31, and the X-axis guide rail is driven by an X-axis drive motor M _X (not shown). A shaft carriage 33 is provided so as to be movable and positionable in the X-axis direction orthogonal to the Y-axis.

Further, the X-axis carriage 33 has an engaging portion 35e provided integrally with a cylindrical W-axis slide 35 extending vertically so as to freely move up and down along the W-axis parallel to the Z-axis. is there. Then, this W-axis slide 35, any W axis through the nut member 38 screwed to the W-axis feed screw 36 which is rotated by the W axis W-axis drive motor M _W provided at the upper end of the slide 35 It can be positioned at the position.

  A Z-axis spindle unit 41 having an electrode holder 39 on which a pipe electrode 37 is mounted is engaged with the W-axis slide 35 described above so as to be movable up and down in the Z-axis direction via a guide member 43 (see FIG. 2). .

1, referring to FIG. 2, the Z-axis spindle unit 41 is a nut screwed to the Z-axis feed screw 44 which is rotated by a Z-axis drive motor M _Z provided on an upper end portion of the W-axis slide 35 A member 46 is provided so as to be movable and positionable to an arbitrary position in the Z-axis direction relative to the W-axis slide 35.

Further, by the spindle motor M _S provided on the top of the Z-axis spindle unit 41, the spindle 111 in the Z-axis spindle unit 41 (see FIG. 4) is provided to be freely rotated.

  An end of the electrode guide unit 73 is detachably provided at the lower end of the W-axis slide 35, and the pipe electrode 37 is slidably inserted into the other end (the Z-axis direction). ) Is provided.

  Further, a funnel member 83 having a taper for guiding the pipe electrode 37 and inserting the pipe electrode 37 is provided immediately above the electrode guide 81.

  Referring again to FIG. 1, an electrode exchange device 87 is provided at the upper end portion of the post 85 erected at the front position of the processing tank 15. In the electrode exchange device 87, a plurality of pipe electrodes 37 mounted on the electrode holder 39 are held by an electrode magazine 86.

  In addition, since the electrode exchange apparatus as described in Unexamined-Japanese-Patent No. 8-290332 which is an application of this applicant can be used for the above-mentioned electrode exchange apparatus 87, detailed description is abbreviate | omitted about the structure.

In the above structure, if appropriately rotates the W-axis drive motor M _W under the control of the control device (not shown), the W-axis slide 35 can be positioned to an appropriate position on the Z axis . That is, the electrode guide 81 that guides the pipe electrode 37 in the Z-axis direction can be positioned at an appropriate position on the Z-axis.

Further, movable positioning the pipe electrode 37 held by the electrode holder 39 by the Z-axis driving motor M _Z to an arbitrary position of the Z-axis.

Further, since the X-axis carriage 33 can be positioned at any position on the X-axis by an X-axis drive motor M _X (not shown), the pipe electrode 37 is moved and positioned at any position on the X and Y coordinates of the workpiece W. In addition, since the workpiece W can be rotated about the A and B axes, it can be positioned at any position other than the bottom surface in addition to the top surface of the workpiece W.

  3 and 4 are diagrams showing the configuration of the electrode holder 39 and the chuck 113. The electrode holder 39 shown in FIG. 3 has a cylindrical outer cylinder 89, and the axial center of the outer cylinder 89 is shown in FIG. Is provided with a through hole 89h through which the working fluid 13 such as pure water can flow, and a collet insertion hole 89c having a diameter larger than that of the through hole 89 is provided below the through hole 89h.

  On the outer circumference of the outer cylinder 89, a circumferential groove 89g for ball engagement is formed. Further, a positioning flange 89f is formed under the circumferential groove 89g, and a cap nut 93 for fastening and fixing the collet 91 is detachably screwed to the lower end portion.

  An axial center of the collet 91 is provided with an insertion hole 91h through which the pipe electrode 37 can be inserted, and a plurality of slits (not shown) are provided in the axial direction in the body part of the collet 91, and an outer peripheral surface at the lower end Is formed with a tapered surface 93t that engages with the tapered portion of the through hole 91t of the cap nut 93.

  In the electrode holder 39 configured as described above, the pipe electrode 37 is inserted into the insertion hole 91h of the collet 91 through the through hole 89h of the outer cylinder 89, and the cap nut 93 is tightened, whereby the pipe electrode 37 is mounted and fixed to the electrode holder 39. Can do.

  As shown in FIG. 4, a chuck 113 is provided at the lower end of the spindle 111 of the Z-axis spindle unit 41. The spindle 111 has a pipe shape, and an annular piston member 115 is fitted into the spindle 111 so as to be movable up and down.

  The piston member 115 is always urged downward by a compression coil spring 117 built in the spindle 111, and a seal ring 119 is provided on the outer peripheral surface of the piston member 115. Further, a seal ring 121 capable of contacting the upper end surface of the electrode holder 39 is provided on the lower surface of the piston member 115.

  A cylindrical ball holding body 123 is screwed and fixed to the outer periphery of the lower end portion of the spindle 111, and a plurality of ball holding holes 125 arranged radially from the axis center are provided near the lower portion of the ball holding body 123. It is provided. In the ball holding hole 125, a detachable ball 127 is held in the ball engaging circumferential groove 89g of the electrode holder 39 so as to be movable by a slight amount in the radial direction.

  A slide ring 129 that can be switched between a state in which the ball 127 is pressed toward the axial center and a state in which the pressure is released is fitted to the outer periphery of the ball holder 123 so as to be movable up and down. Further, a stopper member 131a for preventing the slide ring 129 from dropping from the ball holder 123 and an upper limit position when the slide ring 129 moves upward are provided on the outer periphery of the lower part of the ball holder 123. The stopper member 131b is provided.

  Further, at the lower part of the slide ring 129, when the slide ring 129 moves to the upper limit position, the ball 127 can be moved from the ball holder 123 in the outer circumferential direction and is not detached from the ball holder 123. A ball engagement hole 133 that engages with the ball is provided.

  For the stopper member 131 (a, b), a metal snap ring or a rubber seal ring can be used.

  When the electrode holder 39 is attached to the chuck 113 having the above-described configuration, the head of the electrode holder 39 is moved inside the ball holder 123 in a state where the slide ring 129 is moved to the upper limit position by a slide ring lifting / lowering means (not shown). Since the ball 127 engaged with the head of the electrode holder 39 moves toward the ball engagement hole 133, the ball 127 is inserted to a position where the head of the electrode holder 39 contacts the piston member 115. Can do.

  After contacting the piston member 115, the head of the electrode holder 39 contacts the lower end of the spindle 111 in a state where the ball engaging circumferential groove 89g of the electrode holder 39 is further pushed up to a position where it engages with the ball 127. And stop.

  In this state, by lowering the slide ring 129 to the lower limit position by the slide ring raising / lowering means, the ball 127 is pressed and urged to the ball engaging circumferential groove 89g, and the ball engaging circumferential groove 89g and the ball 127 Is engaged.

  When removing the electrode holder 39, if the slide ring 129 is moved to the upper limit position, the engagement between the ball engaging circumferential groove 89g and the ball 127 is released, and the electrode holder 39 can be pulled out downward. it can.

  The pipe electrode 37 is provided with a processing liquid supply means (not shown) for supplying a processing liquid (pure water).

  The fine hole electric discharge machining apparatus 1 having the above configuration has a funnel-shaped portion that opens upward at the upper portion of the small hole, and the machining area of the funnel-shaped portion changes extremely greatly with respect to the machining area of the fine hole portion. The electric discharge machining method of the shape to be performed will be described.

  5 to 7 show an example of a workpiece 205 having a pyramid-shaped hole 203 opened upward in the upper portion of a narrow hole 201 that obliquely penetrates a flat surface.

  8 to 10 are diagrams for explaining a shape machining path when shape machining is performed on the shape hole 203 of the workpiece 205 by the electric discharge machining method of the present invention.

  9 is a view obtained by cutting the A portion of FIG. 8 along the XZ plane. The program path 207 at the time of electric discharge machining and the electrode consumption amount E at the time of electric discharge machining in the shape machining path in the X-axis direction of the machining area A portion of FIG. It shows the relationship. The program path 207 is based on the center coordinates of the electrodes passing through the inside of the shape hole 203.

That is, the electrode wear amount correction program path 207 in the case of electric discharge during electric discharge machining passes between the points P ₁ and P ₂ between the points P ₁ and P ₂ , and the slope decreases to the right of E / | P ₀ −P ₂ |. It is a straight line. Between P ₂ and P ₃ , the cutting amount ΔZ is lowered in the Z-axis direction in order to perform the next machining, and between P ₃ and P ₄ , the gradient decreases to the left of E / | P ₀ −P ₂ | It is a straight line. Hereinafter, a similar route as shown in FIG. 9 is taken.

  The above-mentioned E is an electrode consumption amount at the time of discharge. Generally, electrode consumption rate (mass ratio) = “electrode consumption amount / workpiece processing amount” or electrode consumption rate (length ratio) = “electrode consumption length” / Workpiece processing depth "or the like.

  FIG. 10 is a three-dimensional schematic diagram showing the A part and the B part of the shape processing path shown in FIG.

  When the shape hole 203 of the workpiece 205 shown in FIG. 8 is machined, the part to be machined first is the A part at the top of the work 205, and then the parts B, C, and D are machined in this order.

  In the case of the shape hole 203 of the workpiece 205, the above-mentioned part A is a portion in which the cross section when the shape hole 203 is cut along the XY plane orthogonal to the Z axis is a “U” shape, and the Y axis The length of the processed surface in the direction is a range in the Z-axis direction in which the length of the pipe electrode 37 used at the time of processing is less than ½. The B section is a portion having a U-shaped cross section, and the length of the processing surface in the Y-axis direction is ½ or more of the diameter of the pipe electrode 37 used during processing and less than the electrode diameter. Is the range in the Z-axis direction.

  Section C is a portion in which the cross-section of the shape hole 203 is a “b” shape, and the length of the machining surface in the Y-axis direction is equal to or greater than the diameter of the pipe electrode 37 used during machining. It is. Further, D portion is a narrow hole portion processed by the pipe electrode 37 that penetrates the shape hole 203 and reaches the back surface of the workpiece.

  As shown in FIG. 10, the relationship between the program path (shown by a broken line) and the actual machining path (shown by a solid line) when machining the shape hole 203 will be described.

In the program path for processing one side in the X-axis direction of the cross section, when the electrode is directly above the portion A, the program path 207 is composed of straight lines passing through points P ₁ and P ₂ in anticipation of the amount of electrode consumption during discharge. However, since the amount of electrode consumption is not corrected because the discharge has not started, the actual machining path 211 is a horizontal path connecting points P ₁ and P ₂ ′ parallel to the X axis. That is, since there is no discharge, the Z axis does not descend.

When the above-mentioned program path 207 reaches the _two points P, there was no lowering of the Z-axis in the previous actual machining path 211 in non-discharge state of the P ₃ points programmed path and the next machining start point without, corrects the _three points P to P _{3 'it} points upward in the Z-axis. That is, the position where the lowered _'downward Z axis cutting-in amount ΔZ from point' by partial P 2 is P _{3 'points} to correct the program path 207 so that the next machining start point.

It is assumed that there is no discharge between P ₃ ′ and P ₄ point, and P ₄ point is reached and discharge is started. At this time, since there is no discharge between P ₃ ′ and P _4, the Z-axis correction corresponding to the amount of electrode consumption is not performed, and the actual machining path 213 moves parallel to the X-axis.

Next, the actual machining path 215 from the point P ₄ moves in parallel with the program path 217 in which the amount of electrode consumption passing through the points P ₃ ′ and P ₆ is corrected. That is, from P _4-point is the discharge starting position, to move the actual machining path 215 for correcting the electrode wear amount.

P ₅ points of the actual machining path, i.e., in the position reached the left end of the X-axis direction of the shape hole 203, to the start point P ₆ points of the next actual machining path 219, in the Z-axis direction by the depth of cut ΔZ min drop To do.

Since the transition to the discharge state from the _{P 4} points, the actual machining path 221 between the actual machining path 219, _{P 8} points -P ₉ points between _{P 6} points -P ₇ points, the program corrects the electrode wear amount pathway Move along the same route as. In addition, the cutting ΔZ in the Z-axis direction is performed between the points P ₅ and P _{6 and the} points P ₇ and P ₈ that move to the next machining start point.

  Next, an actual machining path in the case of machining the portion B where the cross section of the shape hole 203 shown in FIG. 8 is “U” will be described.

Between P ₉ points and P ₁₀ points, a real machining path 223 for processing the Y-axis direction of the machining surface of the workpiece 205, the actual machining path 223 is moved along the processed surface in the Y-axis direction.

And moves down the depth of cut [Delta] Z 'component in the Z-axis direction to move to the P ₁₁ points, which is the next machining start position from P ₁₀ points, P along the P ₁₁ points on the processed surface of the Y-axis direction in the Y-axis direction _A program path is prepared so as to move the program path 227 in consideration of correction of the electrode consumption amount up to ₁₂ points.

However, for example, when a non-discharge state in P ₁₁ points is not performed Z-axis direction of the electrode wear amount of correction, the line correction in the Z-axis direction while moving from P ₁₁ points P ₁₂ points I will not.

As a result, the actual machining path moves on the actual machining path 225 that passes through P ₁₁ and P ₁₂ ′ and is parallel to the Y-axis direction. That is, the machining start point of the next actual machining path 229 is changed from the scheduled P ₁₂ point to the P ₁₂ ′ point.

After P ₁₂ ′, when electric discharge machining is executed without becoming a non-discharge state, the subsequent program path and the actual machining paths (231, 233, 235) are the same.

  Also at the time of electric discharge machining of part C, electric discharge machining is executed according to the same program path as that of part B. That is, the control device (not shown) constantly monitors the discharge state during the electric discharge machining, and if it is determined that the discharge state is not discharged, the amount of electrode consumption in the program path is not corrected, and the discharge state is set. If it is discriminated, processing for correcting the amount of electrode consumption in the program path is performed.

  The electric discharge machining of the D portion is performed in the same manner as the conventional fine hole electric discharge machining, and is performed after the above-described machining of the shape hole 203 is completed.

  Note that the above-described cutting amount ΔZ is a combination of the electrode consumption amount generated when feeding in the Z-axis direction during discharge and the cutting amount for performing the next machining. In the non-discharge state, only the cutting amount ΔZ ′ is obtained by subtracting the amount of electrode consumption from the cutting amount ΔZ (ΔZ ′ <ΔZ).

  FIGS. 11 to 13 are explanatory views of an air-cooled turbine blade TB provided with a large number of fine holes H1 and H2 for flowing out cooling air having different cross-sectional shapes, and such air-cooled turbine blades TB having different cross-sectional shapes , By using the fine hole electric discharge machining method and apparatus of the present invention for machining of H2, efficient and highly accurate machining can be performed.

  The cooling air outflow holes H1 and H2 have funnel-shaped holes F1 and F2 on the upper surface side of the turbine blade TB, and are cooled by jetting the cooling air CG from the inside of the turbine blade along the outer surface. Is what you do. A high-temperature gas G flows on the surface of the turbine blade TB.

DESCRIPTION OF SYMBOLS 1 Thin hole electrical discharge machining apparatus 3 Base 5 Y-axis table 7 Sauce tray 9 Stone surface plate 11 Bracket member 11a Horizontal bottom part 11b B-axis attachment part 13 Processing liquid 15 Processing tank 17 Turntable apparatus 19 B-axis rotating shaft 21 Turntable 25 ( a, b) Column 27 Beam member 31 Bellows 33 X-axis carriage 35 W-axis slide 35e Engaging portion 36 W-axis feed screw 37 Pipe electrode 39 Electrode holder 41 Z-axis spindle unit 43 Guide member 44 Z-axis feed screw 46 Nut member 111 Spindle 73 Electrode guide unit 81 Electrode guide 83 Funnel member 85 Post 86 In electrode magazine 87 Electrode changer 89 Outer cylinder 89c Collet fitting hole 89h Through hole 89g Circumferential groove 89f Flange 91 Collet 91h Insertion hole 91t Through hole 93 Cap nut 93t Tapered surface 111 s ND 113 113 Chuck 115 Piston member 117 Compression coil spring 119, 121 Seal ring 123 Ball holder 125 Ball holding hole 127 Ball 129 Slide ring 131 (a, b) Stopper member 133 Ball engaging hole 201 Narrow hole 203 Shape hole 205 Work 207 , 209, 217, 227 Program path 211, 213, 215, 219, 221, 223, 225, 229 Actual processing path TB Air-cooled turbine blade CG Cooling air
E electrode wear amount F1, F2 shape hole G hot gas H1, H2 small hole M _S spindle motor M _Y Y-axis driving motor M _W W-axis drive motor M _Z Z-axis driving motor W workpiece

Claims (4)

  The shape of the cross-sectional shape part in which the shape of the workpiece is different by using a pipe electrode in water and relatively controlling the three-dimensional position of the electrode and the workpiece in the XYZ axial directions under the control of the control device. In an electric discharge machining method for performing hole machining, during the electric discharge machining along the programmed shape machining path of the electrode, it is determined whether the gap between the electrode and the workpiece is in a non-discharge state or a discharge state. In the discharge state, the Z-axis direction cut is automatically corrected for the programmed electric discharge machining path in consideration of the electrode consumption, and in the no discharge state, the programmed electric discharge machining is performed. A small hole electric discharge machining method, wherein automatic correction of a cut in the Z-axis direction in consideration of an electrode consumption amount is not performed on a path.   The narrow hole electric discharge machining method according to claim 1, wherein in the cross-sectional shape of the shape hole by the XY plane, the length of the shape machining path in the Y-axis direction of the shape machining path is less than ½ of the electrode diameter. Performs a straight machining path in the X-axis direction and a cutting process in the Z-axis direction, and if the length of the shaping machining path in the Y-axis direction is ½ or more of the electrode diameter and less than the electrode diameter, If the length of the Y-axis direction machining path is equal to or greater than the electrode diameter, a U-shaped shape machining path consisting of the direction and the Y-axis direction is performed. A fine hole electric discharge machining method characterized by performing a cutting process in the machining path and the Z-axis direction.   The shape of the cross-sectional shape part in which the shape of the workpiece is different by using a pipe electrode in water and relatively controlling the three-dimensional position of the electrode and the workpiece in the XYZ axial directions under the control of the control device. Whether the electrode is in a non-discharge state or a discharge state between the electrode and the workpiece during the electric discharge machining along the programmed shape machining path in the electric discharge machining apparatus that performs hole machining. When it is in a discharge state, it automatically corrects the cut in the Z-axis direction in consideration of an electrode consumption amount with respect to the programmed electric discharge machining path, and in the case of a no discharge state, the programmed discharge A thin hole electric discharge machining apparatus that does not perform automatic correction of cutting in the Z-axis direction in consideration of an electrode consumption amount with respect to a machining path.   4. The narrow hole electric discharge machining apparatus according to claim 3, wherein in the cross-sectional shape of the shape hole by the XY plane, the length of the shape machining path in the Y-axis direction of the shape machining path is less than ½ of the electrode diameter. Performs a straight machining path in the X-axis direction and a cutting process in the Z-axis direction, and if the length of the shaping machining path in the Y-axis direction is ½ or more of the electrode diameter and less than the electrode diameter, When the length of the Y-axis direction machining path is equal to or longer than the electrode diameter, a U-shaped machining path consisting of a direction and a Y-axis direction is performed. A narrow hole electric discharge machining apparatus characterized by performing cutting in the path and the Z-axis direction.

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