JP2023049341A - Small hole electric discharge machining/laser processing composite processing machine - Google Patents

Abstract

To provide a small hole electric discharge machining/laser processing composite processing machine which can perform small hole electric discharge machining and laser processing with good efficiency.SOLUTION: A small hole electric discharge machining/laser processing composite processing machine 1 comprises: a processing table 26 to which a workpiece W is attached; an electric discharge machining unit 8 which has a rod-like electrode 10a toward the workpiece W attached to the processing table 26 so as to be movable in an axial direction Z of the electrode 10a; and a laser processing unit 9 having a laser processing head 9H which emits laser beam toward the workpiece W attached to the processing table 26. The electric discharge machining unit 8 is relatively movable in surface directions X, Y perpendicular to the axial direction Z with respect to the processing table 26. Also the laser processing unit 9 is relatively movable in the surface directions X, Y with respect to the processing table 26. The laser processing unit 9 comprises a ranging sensor 25 which measures a distance between the same and the workpiece W.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a small hole electric discharge machining/laser machining combined machining machine.

There is a demand to perform small-hole electric discharge machining on a part of a work (object to be processed) after performing laser machining. For example, when a metal portion of a metal work having a ceramic layer formed on its surface is to be subjected to fine hole electric discharge machining, the ceramic layer is an insulating layer, so electric discharge machining cannot be performed. In such a case, it is desired to remove the ceramic layer by laser processing to expose the metal portion, and then perform small hole electric discharge machining.

Here, it is conceivable to remove the work from the laser processing machine after performing laser processing on the work with the laser processing machine, and then attach the work to the small hole electric discharge machine to perform the small hole electric discharge machining. When it is necessary to machine a large number of small holes in a work, it is not practical to alternately use a laser processing machine and a small hole electric discharge machine for each hole. Therefore, it is practical to mount the work on a small-hole electric discharge machine and perform electric discharge machining after completing the laser machining for all the holes of the work by the laser machine.

However, setting the workpiece to the processing machine must be performed twice. In addition, there is a possibility that the workpiece may be slightly deformed due to processing heat during laser machining, making it difficult to set the workpiece for small-hole electrical discharge machining, and the electrical discharge machining itself may also become difficult. Here, as shown in Patent Documents 1 to 3 below, there is also known a multi-tasking machine having both a laser processing function and an electrical discharge function.

JP-A-11-197947 JP-A-2-251323 JP 2018-83224 A

The multi-tasking machine disclosed in Patent Document 1 is intended to improve the accuracy and efficiency of metal processing by using electric discharge machining in combination with laser processing. Therefore, although it is a multi-tasking machine, it is not intended to be used for machining in which small hole electric discharge machining is performed after laser machining as described above.

The multi-tasking machine disclosed in Patent Document 2 performs rough machining by laser machining and then finish machining by electric discharge machining. is intended. Therefore, as described above, it is not intended to be used for small hole electric discharge machining after laser machining.

The multitasking machine disclosed in Patent Document 3 uses water jet laser processing as a laser processing function. In the water jet laser processing of this multitasking machine, a laser beam is guided inside a water column ejected from a hollow electrode for small hole electric discharge machining. For this reason, a mechanism for forming a water jet is required, and an electrode for small-hole electric discharge machining also needs a structure that considers the formation of a water jet. In addition, since the water jet is formed inside the electrode for small hole electric discharge machining, there is a limit to reducing the outer diameter of the electrode. Although it may be possible to replace the electrode with one having a smaller outer diameter after laser processing, a replacement process is required and positioning of the processing position becomes difficult, which complicates the processing process.

SUMMARY OF THE INVENTION An object of the present invention is to provide a small hole electric discharge machining/laser machining combined machine capable of efficiently performing laser machining and small hole electric discharge machining without using a special structure such as a water jet laser. be.

A small hole electric discharge machining/laser machining combined machine according to the present invention performs small hole electric discharge machining and laser machining on a work. A multi-tasking machine has a machining table on which a workpiece is attached, and a rod-like electrode movably directed toward the workpiece attached to the machining table in the axial direction of the electrode, and perpendicular to the machining table in the axial direction. and a laser processing head that emits a laser beam toward a workpiece attached to a processing table, and is relatively movable in the above-mentioned planar direction with respect to the processing table. and a laser processing unit. A laser processing unit has a distance sensor that measures the distance to the workpiece.

1 is a front view of a small hole electric discharge machining/laser machining combined machine according to a first embodiment; FIG. It is a side view of the multi-tasking machine. 3 is an enlarged front view of an electric discharge machining head of the multi-tasking machine; FIG. 4 is a plan view of a deflection detection arm of the electrical discharge machining head; FIG. 3 is a block diagram of the multi-tasking machine; FIG. 1 is a perspective view of a turbine blade as an example of a work; FIG. It is a sectional view of the work. FIG. 5 is a plan view for explaining focus calibration of the laser processing unit of the multitasking machine; It is a top view explaining the horizontal offset calibration of the said laser processing unit. FIG. 5 is a plan view for explaining horizontal offset calibration of the small-hole electric discharge machining unit of the multitasking machine; It is a front view of a small hole electric discharge machining / laser machining combined processing machine according to a second embodiment. It is a side view of the multi-tasking machine.

A small hole electric discharge machining/laser machining combined machine 1 (hereinafter simply referred to as a combined machine 1) according to an embodiment will be described with reference to the drawings.

First, a multitasking machine 1 according to the first embodiment will be described with reference to FIGS. 1 to 10. FIG. As shown in FIGS. 1 and 2, the multitasking machine 1 includes a main unit 2, a control unit 3 (shown only in FIG. 1), and a working fluid circulation unit 4 (shown only in FIG. 2). A working fluid circulation unit 4 is arranged behind the main unit 2 and is not shown in FIG. Also, the control unit 3 is not shown in FIG. In addition, in FIGS. 1 and 2, illustration of wiring and piping connecting each unit is omitted.

The main unit 2 includes a main carriage 5, a Y-axis carriage 6a and an X-axis carriage 7a. The main carriage 5 is fixed to the Y-axis carriage 6a. The Y-axis carriage 6a (and the main carriage 5) can move in the Y-axis direction (horizontal direction in FIG. 2) along the Y-axis rail 6b. Movement of the Y-axis carriage 6a in the Y-axis direction with respect to the Y-axis rail 6b is performed by a Y-axis motor 6c (see FIG. 5) such as an electric servomotor, and the Y-axis motor 6c is controlled by an NC control unit 28, which will be described later. NC is an abbreviation for Numerical Control. The Y-axis rail 6b is fixed on the X-axis carriage 7a.

The X-axis carriage 7a is movable in the X-axis direction (horizontal direction in FIG. 1) perpendicular to the Y-axis direction along the X-axis rail 7b. Movement of the X-axis carriage 7a in the X-axis direction with respect to the X-axis rail 7b is performed by an X-axis motor 7c (see FIG. 5) such as an electric servomotor, and the X-axis motor 7c is also controlled by an NC control unit 28, which will be described later. The X-axis rail 7 b is fixed to the housing frame of the main unit 2 . That is, the main carriage 5 is movable in the X-axis direction and the Y-axis direction. The X-axis direction and the Y-axis direction are horizontal directions in this embodiment. In this embodiment, the horizontal direction is a plane direction perpendicular to the axial direction of the electrode 10a of the electric discharge machining unit 8, which will be described later.

An electric discharge machining unit 8 and a laser machining unit 9 that are vertically movable with respect to the main carriage 5 are attached to the front surface of the main carriage 5 . The electrical discharge machining unit 8 is vertically movable along the W1 axis (see reference sign W1 in FIG. 1). Movement of the electric discharge machining unit 8 in the W1-axis direction is performed by a W1-axis motor 8c (see FIG. 5) such as an electric servomotor, and the W1-axis motor 8c is also controlled by an NC control unit 28, which will be described later.

On the other hand, the laser processing unit 9 is vertically movable along the W2 axis (see reference sign W2 in FIG. 1). Movement of the laser processing unit 9 in the W2-axis direction is performed by a W2-axis motor 9c (see FIG. 5) such as an electric servomotor, and the W2-axis motor 9c is also controlled by an NC control unit 28, which will be described later. 1 and 2, the laser processing unit 9 is positioned at its highest position. On the other hand, the electric discharge machining unit 8 is located at a position slightly lowered from its highest position. Therefore, in FIG. 2, only the electrode holder 10b and the electrode guide 11 (these will be described below) positioned at the bottom of the electrical discharge machining unit 8 are shown behind the laser machining unit 9. As shown in FIG.

The electrical discharge machining unit 8 will be described in more detail with reference to FIGS. 3 and 4 in addition to FIGS. 1 and 2. FIG. An electrode holder 10b for mounting a hollow or solid rod-shaped electrode 10a is provided at the bottom of the electrical discharge machining unit 8 . The electrode holder 10b is vertically movable with respect to the electric discharge machining unit 8 along the Z-axis (see reference symbol Z in FIG. 1) (when viewed from the front, the Z-axis and W1-axis appear to overlap. ing). The Z-axis is the axial direction of the rod-shaped electrode 10a attached to the electrode holder 10b, and is the vertical direction in this embodiment. Also, the Z-axis is parallel to the W1-axis and W2-axis described above. That is, the XYZ axes described above form an orthogonal coordinate system, and the W1 and W2 axes are parallel to the Z axis.

A discharge is generated between the tip of the electrode 10a and the work W to form a hole in the work W. As the depth of the hole increases, the electrode 10a needs to be stroked downward. Also, the tip of the electrode 10a is worn out with the discharge, and the length of the electrode 10a is gradually shortened. It is necessary to stroke the electrode holder 10b (that is, the electrode 10a) including this consumption. For this purpose, the electrode 10a is moved along the Z-axis relative to the EDM unit 8 during electrical discharge machining. Movement of the electrode 10a (electrode holder 10b) in the Z-axis direction with respect to the electric discharge machining unit 8 is performed by a Z-axis motor 10c (see FIG. 5) such as an electric servomotor, and the Z-axis motor 10c is also controlled by an NC control unit 28, which will be described later. be done.

An electrode guide 11 is provided below the electrode holder 10b. The electrode guide 11 is basically fixed to the electrical discharge machining unit 8 and moves vertically as the electrical discharge machining unit 8 moves in the W1 axis direction. However, the vertical position of the electrode holder 10b with respect to the electric discharge machining unit 8 is adjustable. Since the electrode 10a is thin and long, its tip tends to sway in the horizontal direction. Therefore, the vicinity of the tip of the electrode 10 a is inserted through the through hole of the electrode guide 11 and the tip of the electrode 10 a is guided by the electrode guide 11 .

The electric discharge machining unit 8 has a deflection detection mechanism for detecting deflection of the electrode 10a. As described above, the electrode 10a is moved downward during electrical discharge machining. The deflection detection mechanism detects such deflection of the electrode 10a. As shown in FIGS. 3 and 4, the deflection detection mechanism has a detection plate 12a as its detection portion. The detection plate 12 a is made of a conductive member, specifically metal, and is arranged between the electrode holder 10 b and the electrode guide 11 . The detection plate 12a has an insertion hole 12b through which the electrode 10a is inserted, and a slit for inserting the electrode 10a into the insertion hole 12b is formed at the tip of the detection plate 12a.

The detection plate 12a is fixed to a vertical bracket 12d via an insulating plate 12c. The vertical bracket 12d is fixed to the electric discharge machining unit 8. As shown in FIG. However, the vertical positions of the detection plate 12a and the insulation plate 12c with respect to the electrical discharge machining unit 8 are adjustable. The deflection detection mechanism also includes a deflection detector 12e. Deflection detector 12e detects this contact when electrode 10a is deflected into contact with sensing plate 12a. During electrical discharge machining, a detection voltage is applied between the electrode holder 10b (that is, the electrode 10a) and the detection plate 12a, and when the electrode 10a bends and contacts the detection plate 12a, a closed circuit is formed. Voltage drops. The deflection detector 12e detects this voltage to detect the deflection of the electrode 10a. The deflection detector 12e is connected to an NC control unit 28, which will be described later.

The electric discharge machining unit 8 also includes a voltage detector 13 or a current detector 14, as shown in FIG. 3, in order to monitor whether the electric discharge machining is being performed normally. Note that the electric discharge machining unit 8 may include both the voltage detector 13 and the current detector 14 . The voltage detector 13 detects the voltage applied between the electrode 10a and the workpiece W by the electric discharge machining power supply 29, and monitors whether the electric discharge machining is being performed normally based on the change in this voltage. do. The current detector 14 detects the current of electric discharge machining power supplied by the electric discharge machining power source 29, and monitors whether or not the electric discharge machining is being performed normally based on the change in this current. Reference numeral 15 in FIG. 3 denotes a semiconductor switch for outputting electric discharge machining power in pulses, and reference numeral 16 denotes a discharge capacitor for storing electric power until the start of discharge.

Next, the laser processing unit 9 will be described in more detail with reference to FIGS. 1 and 2 as well as FIG. The laser processing unit 9 has a laser processing head 9H (see FIG. 5) at its lower portion. In FIG. 5, the configuration of the laser processing head 9H is taken out and shown in the lower part of the drawing. A laser processing head 9</b>H is fixed to the laser processing unit 9 . The laser processing head 9H has a laser emitting section 17, two galvanometer mirrors 18, two mirror motors 19 for driving the galvanometer mirrors 18, a condenser lens 20, and the like. The configuration of the laser processing head 9H is the same as that of a normal laser processing head.

As shown in FIG. 5, the multi-tasking machine 1 includes a laser controller 21, a laser oscillator 22, a galvanomirror controller 23, and a motor driver 24 in association with the laser processing head 9H. These are provided inside the laser processing unit 9 or the main unit 2 . The laser emitting section 17 described above is connected to the laser oscillator 22 by an optical fiber. The laser emitting section 17 is connected to an NC control unit 28 to be described later via a laser controller 21 and a galvanomirror controller 23 . Also, the mirror motor 19 is connected to a galvanometer mirror controller 23 via a motor driver 24 , and the galvanometer mirror controller 23 is connected to an NC control unit 28 . Laser light emission is controlled by these controllers.

The laser processing unit 9 further includes a distance sensor 25 that measures the distance to the work W. As shown in FIG. The distance measuring sensor 25 of the present embodiment is specifically a laser displacement sensor, and also emits a target laser beam for making the measurement position easy to understand at the time of measurement. A distance measuring sensor 25 is fixed to the laser processing unit 9 . As described above, the laser processing head 9H is also fixed to the laser processing unit 9, and the positional relationship between the distance measuring sensor 25 and the laser processing head 9H in the laser processing unit 9 remains unchanged. Therefore, the distance between the laser processing head 9H and the workpiece W can be measured by the distance measuring sensor 25. FIG. In addition, the measurement by the distance measurement sensor 25 is performed by moving the laser processing unit 9 in the X-axis direction and the Y-axis direction to position the distance measurement sensor 25 directly above the measurement position (for example, a specific location on the work W). conduct.

The main unit 2 also has a processing table 26 on which the workpiece W is attached below the electric discharge processing unit 8 and the laser processing unit 9 described above. During electrical discharge machining, the workpiece W is submerged in a machining fluid (pure water is used in this embodiment), and if the electrode 10a is hollow, the machining fluid is also supplied from the tip through the interior. Therefore, the machining table 26 is positioned inside the machining tank 27 . The machining table 26 is rotatable around an A-axis (second rotation axis: see reference symbol A in FIGS. 1 and 2) perpendicular to the mounting surface of the workpiece W. As shown in FIG. The A-axis direction is parallel to the above-described Z-axis direction (and the W1-axis direction and W2-axis direction). Rotation of the machining table 26 about the A axis is performed by an A axis motor 26a (see FIG. 5) such as an electric servomotor, and the A axis motor 26a is also controlled by an NC control unit 28, which will be described later.

The machining table 26 is also rotatable around a B-axis (first axis of rotation: see reference symbol B in FIG. 2) that is perpendicular to the A-axis. The A-axis direction is parallel to the above-described Z-axis direction (and the W1-axis direction and W2-axis direction). Rotation of the machining table 26 around the B-axis is performed by a B-axis motor 26b (see FIG. 5) such as an electric servomotor, and the B-axis motor 26b is also controlled by an NC control unit 28, which will be described later. As shown in FIGS. 3 and 5, in this embodiment, the machining table 26 is connected as an anode to a power source 29 for electrical discharge machining, and the power source 29 for electrical discharge machining is connected to the electrical discharge machining unit 8 side (the electrode holder 10b and the electrode 10a). connected as a cathode to

Inside the control unit 3 shown in FIG. 1, there are an NC control unit 28 (see FIG. 5) that performs machining by NC controlling the electric discharge machining unit 8 and the laser machining unit 9, and an electric discharge machining power source 29 (see FIG. 5). See) and are built-in. As shown in FIG. 5, the NC control unit 28 (control section) controls the motors and the like described above for NC control. Motors for NC control of the electric discharge machining unit 8 and laser machining unit 9 are connected to the NC control unit 28 via a motor driver 30 . In this embodiment, the deflection detector 12e, the voltage detector 13, and the current detector 14 are also connected to the control unit 3, and based on their detection values, the NC control unit 28 or the like controls the multi-tasking machine. 1 operation is controlled.

The control unit 3 (control section) has an operation panel 31 on its top. Various settings for processing can be made through the operation panel 31 . It is also possible to manually control the machining through the operation panel 31 . A wired controller 32 is also held on the operation panel 31, and the operator can remove the wired controller 32 from the operation panel 31 and perform setting and control while visually observing the working situation.

The machining fluid circulation unit 4 shown in FIG. 2 includes a machining fluid tank 40 (see FIG. 5), a machining fluid pump 41 and a machining fluid filter 42 . The machining fluid pump 41 is connected to the NC control unit 28 (see FIG. 5), and its operation is controlled by the NC control unit 28 . The machining fluid filter 42 removes machining debris from the machining fluid before supplying the machining fluid recovered from the machining tank 27 to the main unit 2 again. The NC control unit 28 controls the machining fluid pump 41 and valves (not shown) to supply the machining fluid through the hollow electrode 10a and adjust the level of the machining fluid in the machining tank 27 during electric discharge machining. Control. The machining position of the workpiece W is exposed from the machining fluid during laser machining, and is immersed in the machining fluid during electric discharge machining. Therefore, when switching between laser machining and electrical discharge machining, the level of the machining fluid in the machining tank 27 is controlled by the NC control unit 28 .

Next, the machining of the workpiece W by the multitasking machine 1 described above will be explained. First, the workpiece W to be machined in this embodiment will be explained with reference to FIGS. 6 and 7. FIG. The workpiece W to be machined in this embodiment is a cast turbine rotor blade for thermal power generation. Since such turbine blades are required to have high heat resistance, the turbine blades are cast from a heat-resistant alloy. This casting method has also evolved from a normal method to a special casting method such as a columnar crystal method or a single crystal method. In addition, so-called film cooling is performed by ejecting fluid (air) from the inside of the turbine blade through a large number of film cooling holes 100 (or slits) formed on the surface of the turbine blade to form a thermal insulation layer of the fluid on the surface of the turbine blade. done. Furthermore, the surface of the turbine blade is coated with a heat-resistant coating made of low-thermal-conductivity ceramic called TBC (Thermal Barrier Coating) in order to improve heat resistance.

Film cooling holes 100 are difficult to form when casting a turbine blade. Further, if the film cooling hole 100 is formed by drilling or electric discharge machining after casting the turbine blade and then the TBC is formed, the formed film cooling hole 100 may be blocked by the TBC or the hole shape may be changed, causing fluid flow. In some cases, the formation of the heat insulating layer is hindered. Therefore, as described in the Background Art section, the TBC is removed by laser machining to expose the refractory metal portion, and then the film cooling holes 100 are formed by small hole electrical discharge machining. According to the multi-tasking machine 1 of the present embodiment, it is possible to easily perform electric discharge machining after performing laser machining on the workpiece W attached to the machining table 26 .

Note that the dimensional accuracy of the cast product is not so high, and a slight dimensional error may occur in the actual shape after casting with respect to the drawing shape. Here, as shown in FIG. 7, consideration is given to forming film cooling holes 100 on the surface of the workpiece W of the present embodiment, that is, the turbine blade which is a casting. In this case, the film cooling holes 100 are formed on a complicated three-dimensional curved surface that is considerably inclined with respect to the processing direction (see the dotted arrow in FIG. 7). For this reason, the position of the film cooling hole 100 on the workpiece W is greatly shifted even if the processing position is slightly shifted in the horizontal direction, so the positioning of the processing position is important. In particular, considering laser processing, it is necessary to converge the laser beam at the processing position. , the positioning of the machining position is also important. In this embodiment, such a problem is solved by using the distance measuring sensor 25 described above.

[Processing of work W]
(Calibration before processing)
The calibration described below does not need to be performed each time one film cooling hole 100 is processed. Just do it.

<Vertical Calibration of Laser Beam Focus of Laser Processing Unit 9>
First, the flat metal plate 101 (see FIG. 8) for calibration is set horizontally on the processing table 26 . Next, the slit 102 is processed in the metal plate 101 while moving the laser processing head 9H step by step in the W2 axis direction (vertical direction). During processing of each slit 102, the slit 102 is formed in the Y direction while the laser processing head 9H is moved in the Y-axis direction at each vertical position. Also, the processing position of each slit 102 is shifted in the X-axis direction, but this is done by moving the laser processing head 9H in the X-axis direction.

FIG. 8 shows a plan view of the flat metal plate 101 after processing the slit 102. In the case of FIG. 8, the center slit width is the narrowest, and it can be determined that the focus of the laser beam is the optimum value when the slit 102 is formed. . Therefore, next, the distance between the laser processing head 9H and the metal flat plate 101 at this time is measured by the distance measuring sensor 25. FIG. Specifically, the laser processing head 9H is realigned with the vertical position of the laser processing head 9H when processing the center slit 102 . In this state, the worker moves the laser processing unit 9 in the horizontal direction (X-axis direction and Y-axis direction) so that the measurement position of the distance measuring sensor 25 is aligned with the point C in the drawing immediately beside the central slit 102 . ) and then the distance is measured. This measured distance is calibrated as the optimum distance between the processing position of the workpiece W and the laser processing head 9H (that is, the laser processing unit 9).

The reason why the optimum distance is measured later using the point C in this way is that the distance measured by the distance measuring sensor 25 is the distance to the measurement position vertically below. The laser processing position (laser optical axis position) of the laser processing head 9H and the measurement position of the distance measuring sensor 25 are offset in the horizontal direction. Therefore, during laser processing by the laser processing head 9H, the accurate distance between the processing position and the laser processing head 9H cannot be measured. Therefore, the calibration is accurately performed using the point C later in this manner.

<Calibration of horizontal offset between laser processing position and distance measuring sensor 25>
Next, the horizontal offset between the laser processing position and the distance measuring sensor 25 is measured. Specifically, first, a new flat metal plate 103 (see FIG. 9) is set horizontally on the processing table 26 . Then, as shown in FIG. 9, a square (or rectangular) hole 104 is formed in the metal flat plate 103 by laser processing. At this time, the laser processing head 9H is moved in the X-axis direction and the Y-axis direction, and each side of the hole 104 becomes parallel to the X-axis direction or the Y-axis direction. At this time, the coordinates of "the center O of the hole 104 regarding laser processing" can be calculated.

Next, the distance measuring sensor 25 is moved in the X-axis direction or the Y-axis direction as indicated by the dotted arrows in FIG. 9 to detect each side of the hole 104 . Since the distance to be measured changes at the edge of each side of the hole 104 when detected by the distance measuring sensor 25 , each side can be calculated by the distance measuring sensor 25 . As a result, since it is known that each side is parallel to the X-axis direction or the Y-axis direction as described above, the coordinates of "the center O of the hole 104 with respect to the distance measuring sensor 25" can also be calculated.

Then, by comparing the coordinates of "the center O of the hole 104 with respect to laser processing" and the coordinates of "the center O of the hole 104 with respect to the distance measuring sensor 25", the horizontal direction of the laser processing position and the distance measuring sensor 25 is determined. can calculate (measure) the offset of As a result, the laser processing head 9H is accurately moved in the horizontal direction (X-axis direction and Y-axis direction) so that the distance from the laser processing position (the laser focal position vertically below the laser irradiation part) can be measured by the distance measuring sensor 25. can be made

<Calibration of horizontal offset between electrode 10a for electric discharge machining and laser processing position>
Since the calibration of the horizontal offset between the laser processing position and the distance measuring sensor 25 is completed by the above calibration, the horizontal offset between the electrode 10a for electric discharge machining and the laser processing position is calibrated next. Specifically, first, the electrode 10a is inserted into the hole 104 described above. At this time, the flat metal plate 103 having the holes 104 is used as it is without being removed from the processing table 26 .

10, the electrical discharge unit 8, that is, the electrode 10a is moved in the X-axis direction or the Y-axis direction to detect each side of the hole 104. As shown in FIG. Such functionality is also provided in conventional small hole EDMs. When the electrode 10a contacts the metal flat plate 103, a closed circuit including the electrode 10a and the metal flat plate 103 is established, and the flowing current is detected by an ammeter. Each side of the hole 104 can be detected by detecting with a meter. As a result, since it is known that each side is parallel to the X-axis direction or the Y-axis direction as described above, the coordinates of "the center O of the hole 104 with respect to the electrode 10a" can also be calculated.

Then, by comparing the coordinates of "the center O of the hole 104 with respect to the electrode 10a" and the coordinates of "the center O of the hole 104 with respect to the distance measuring sensor 25", the horizontal direction between the electrode 10a and the distance measuring sensor 25 is determined. The offset can be calculated (measured). As described above, the horizontal offset between the coordinates of "the center O of the hole 104 with respect to laser processing" and the coordinates of "the center O of the hole 104 with respect to the distance measuring sensor 25" has already been calibrated. Therefore, the offset between the coordinates of "the center O of the hole 104 with respect to the electrode 10a" and the coordinates of "the center O of the hole 104 with respect to the laser processing" can also be calculated (measured). That is, the horizontal offset between the electric discharge machining position and the laser machining position can also be calculated (measured).

As a result, the electric discharge machining unit 8 can be moved horizontally (in the X-axis direction and the Y-axis direction) so as to quickly move the electrode 10a to the laser machining position after laser machining and shift to electric discharge machining. Conversely, the laser processing unit 9 is moved in the horizontal direction (X-axis direction and Y-axis direction) in order to quickly move the laser processing head 9H to the electrical discharge processing position after the electrical discharge processing and shift to laser processing. be able to. Furthermore, the electric discharge machining head (electric discharge machining unit 8) is accurately moved in the horizontal direction (X-axis direction and Y-axis direction) to measure the distance from the electric discharge machining position (vertical lower position of the electrode 10a) with the distance measuring sensor 25. You can also let

Thus, the calibration ends. As described above, the calibration may be performed at a predetermined time, but only the calibration for the electrode 10a may be performed again when the electrode 10a is replaced.

(laser processing)
With the above-described calibration, preparations for accurate NC control of electric discharge machining and laser machining are now complete. Processing will be explained. First, the work W is set on the processing table 26 . The machining table 26 is rotated around the A-axis and the B-axis, and the machining position of the workpiece W is oriented in a direction suitable for machining. Since laser processing is performed prior to electric discharge machining, the processing fluid is not filled in the processing tank 27, or even if the processing fluid is filled in the processing tank 27, the laser processing position is above the liquid surface. The liquid level is controlled by the NC control unit 28 so that In addition to controlling the liquid surface position of the machining fluid in the machining tank 27, the movement of each unit described below, the electrical discharge machining by the electrical discharge machining unit 8, and the laser machining by the laser machining unit 9 are also controlled by the NC control unit. 28.

Next, according to the processing program, the laser processing unit 9 is moved in the X-axis direction and the Y-axis direction so that the measurement position of the distance measuring sensor 25 matches the processing position on the surface of the work W. In parallel with this, or after the horizontal movement of the laser processing unit 9 is completed, the distance between the laser processing head 9H and the processing position on the surface of the work W is measured by the distance measuring sensor 25, and the above-described optimal distance ( focal length), the laser processing head 9H is moved in the W2-axis direction. As described above, the workpiece W of the present embodiment is a cast product, so the dimensional accuracy is not very high. Therefore, the position of the laser processing head 9H in the W2-axis direction is not set based on the program drawing shape, but is set based on the actual shape while being measured by the distance measuring sensor 25. FIG.

At this time, the vertical position of the laser processing head 9H in the W2-axis direction is stored. By reflecting the stored position in the drawing shape on the program and correcting the shape data in the program, the laser processing accuracy at the next processing position (film cooling hole 100) can be improved. Alternatively, this memory may be made for every film-cooling hole 100 to be processed so that the program reflects all the stored film-cooling hole 100 positions. Such correction processing can be applied not only to the correction processing for the single work W, but also to the correction processing for other works W of the same specification (lot).

After that, the laser processing unit 9 is moved in the X-axis direction and the Y-axis direction so that the laser processing position becomes the processing position on the surface of the work W, and laser processing is performed. The horizontal movement of the laser processing unit 9 to the laser processing position is performed without any problem because the horizontal offset between the laser processing position and the distance measuring sensor 25 is calibrated as described above. The insulating layer on the surface of the workpiece W is removed by laser processing. It should be noted that scanning with a laser beam matching the size of the film cooling hole 100 to be formed is performed by scanning the laser beam with a galvanometer scanner unit. Since the focal position of laser processing is set correctly, it is possible to avoid insufficient removal of the insulating layer due to defocus.

Note that laser processing is performed, for example, for each row of a plurality of film cooling holes 100 . It is conceivable that slight thermal deformation of the work W may occur due to heat generated by the laser processing while the plurality of film cooling holes 100 in a row are being laser processed. However, even in such a case, since correction processing is performed based on the measurement result of the distance measuring sensor 25, the laser processing head 9H can be set at the optimum distance, and laser processing defects can be avoided.

(electrical discharge machining)
Electric discharge machining is performed after laser machining. First, the machining tank 27 is filled with the machining fluid so that the electric discharge machining position is below the liquid surface of the machining fluid. Next, small hole electric discharge machining is sequentially performed on machining positions on the workpiece W for which laser machining has been completed. At this time, the electric discharge machining unit 8, that is, the movement of the electrode 10a in the X-axis direction and the Y-axis direction can be performed based on the horizontal offset from the distance measuring sensor 25 (or the laser processing head 9H) during laser processing. can. As described above, since the horizontal offsets of the electrode 10a, distance measuring sensor 25 and laser processing head 9H have already been calibrated, it is possible to match the horizontal processing positions in electrical discharge machining with laser processing.

Further, the relationship between the reference position of the electric discharge machining unit 8 in the W1-axis direction and the reference position of the laser processing unit 9 in the W2-axis direction in the multitasking machine 1 is fixed. Therefore, the initial position of the tip of the electrode 10a in the vertical direction is the W2-axis position of the laser processing head 9H stored for each film cooling hole 100 in laser processing via the initial position of the W1-axis direction of the electrical discharge machining unit 8. can be set based on After the position of the electrode 10a in the vertical direction, that is, the position of the electric discharge machining unit 8 in the W1 axis direction is set in this manner, the film cooling hole 100 is formed by electric discharge machining. Movement of the electrode 10a during electrical discharge machining is in the Z-axis direction.

At this time, since the insulating layer is previously removed by laser processing, the film cooling hole 100 can be reliably formed in the metal portion of the electrode 10a. Electrical discharge machining is performed, for example, on a row of previously formed film cooling holes 100 . After that, similarly, after the liquid level of the working liquid in the processing tank 27 is lowered and the laser processing is performed on the film cooling holes 100 in the other row, the liquid level of the working liquid in the processing tank 27 is raised. Then, the thin hole electric discharge machining of the film cooling holes 100 of the other row is performed.

In the case where the opening end of the film cooling hole 100 is to have a diffuser shape, the insulating layer in the range where the diffuser shape is formed is removed during laser processing. In such laser processing, a galvanometer scanner is used to change the irradiation position of the laser beam, or the laser processing head 9H (laser processing unit 9) is moved in the horizontal direction. By moving the laser processing head 9H in the W2-axis direction as necessary, it is possible to cope with changes in the vertical direction of the laser processing position. Then, the diffuser shape is formed on the surface of the work W by electrical discharge machining. In such electric discharge machining, the electrode 10a (the electric discharge machining unit 8) is also moved horizontally to carry out the electric discharge machining. By moving the electrode 10a in the Z-axis direction as necessary, it is possible to cope with changes in the depth direction of the diffuser shape.

<Detection of electrical discharge machining defects>
In this embodiment, the deflection detector 12e, the voltage detector 13, and/or the current detector 14 shown in FIG. 3 can be used to detect electrical discharge machining defects during electrical discharge machining. Any of the three methods of using these detectors may be used alone, or two or three of them may be used in combination.

First, the case of using the deflection detector 12e will be described. If the insulating layer is incompletely removed by laser processing as described above, the film cooling hole 100 will not be formed normally due to defective electrical discharge and processing defects. In this case, when the electrode 10a is moved downward along the Z-axis, the electrode 10a comes into contact with the workpiece W and bends. When the electrode 10a bends and contacts the inner peripheral edge of the insertion hole 12b of the detection plate 12a, the bending of the electrode 10a is detected by the deflection detector 12e. This makes it possible to detect electrical discharge machining defects.

Next, the case of using the voltage detector 13 will be described. As described above, the discharge voltage is applied between the electrode 10a (the anode in this embodiment) and the workpiece W (the same cathode) by the electric discharge machining power supply 29. As shown in FIG. A voltage detector 13 monitors this voltage. After the voltage is increased to a predetermined value required for electrical discharge machining, it is decreased by electrical discharge, and this is repeated at high intervals. If a discharge failure occurs, no discharge occurs even if the electrode 10a is moved downward by a predetermined distance. Therefore, if the voltage is higher than a predetermined value even after the electrode 10a is moved downward by a predetermined distance, it is detected that an electric discharge machining defect has occurred.

Finally, the case of using the current detector 14 will be described. As described above, a predetermined amount of current flows between the electrode 10a and the workpiece W during discharge. A current detector 14 monitors this current. The current does not flow unless electrical discharge machining is performed, and if the electrical discharge machining is insufficient, the current becomes smaller than the predetermined value. Therefore, if the current is lower than the predetermined value even after the electrode 10a is moved downward by a predetermined distance, it is detected that an electric discharge machining defect has occurred.

When an electrical discharge machining defect is detected in this manner, the electrical discharge machining for the film cooling hole 100 is stopped and the electrical discharge machining for the next film cooling hole 100 is started. For the film cooling holes 100 that have not been electro-discharge-machined, the multi-tasking machine 1 is manually operated to form the film cooling holes 100 again. For example, manual laser machining is performed to completely remove the insulating layer, and then fine hole electrical discharge machining is performed to form the film cooling holes 100 . As described above, the multi-tasking machine 1 performs laser machining and small-hole electric discharge machining.

According to this embodiment, the multitasking machine 1 includes an electric discharge machining unit 8 , a laser machining unit 9 , and a machining table 26 . The electric discharge machining unit 8 can move the rod-shaped electrode 10a toward the machining table 26 in its axial direction (Z-axis direction). The electric discharge machining unit 8 is relatively movable with respect to the machining table 26 in plane directions (X-axis direction and Y-axis direction) perpendicular to the axial direction. The laser processing unit 9 has a laser processing head 9H that emits laser light toward (the work W attached to) the processing table 26 . The laser processing unit 9 is relatively movable with respect to the processing table 26 in the plane direction (X-axis direction and Y-axis direction). The laser processing unit 9 has a distance sensor 25 for measuring the distance to the work W. As shown in FIG.

The multitasking machine 1 includes both the electric discharge machining unit 8 and the laser processing unit 9, and the laser processing unit 9 includes the distance measuring sensor 25. can be set accurately. Further, while measuring the distance from the actual processing position on the workpiece W by the distance measuring sensor 25, the focus position of the laser processing unit 9 can be adjusted to the processing position. Furthermore, without removing the workpiece W from the processing table 26, the laser machining by the laser machining unit 9 and the small hole electrical discharge machining by the electrical discharge machining unit 8 can be continuously performed, so that the laser machining and the small hole electrical discharge machining can be combined. Machining can be performed continuously with high accuracy. Since one multi-tasking machine 1 includes the electric discharge machining unit 8 and the laser processing unit 9, the detection result of the distance measuring sensor 25 provided in the laser processing unit 9 can also be used for electric discharge machining by the electric discharge machining unit 8. Also, the machining accuracy between laser machining and electrical discharge machining can be improved. As a result, laser processing and small-hole electrical discharge machining can be performed efficiently.

Further, according to the present embodiment, the electric discharge machining unit 8 and the laser machining unit 9 move the electrodes 10a in the axial direction (vertical direction) on the main carriage 5 that is movable in the planar direction (horizontal direction: X-axis direction, Y-axis direction). : Z-axis direction, W1-axis direction, W2-axis direction). That is, the electrical discharge machining unit 8 (electrode 10 a ) is relatively moved in the plane direction (horizontal direction) with respect to the machining table 26 by moving the electrical discharge machining unit 8 in the plane direction by the main carriage 5 . Similarly, relative movement of the laser processing unit 9 (laser processing head 9H) in the plane direction (horizontal direction) with respect to the processing table 26 is also performed by moving the laser processing unit 9 in the plane direction by the main carriage 5 . Therefore, the mechanism for moving the electric discharge machining unit 8 in the plane direction and the mechanism for relatively moving the laser machining unit 9 in the plane direction with respect to the processing table 26 can be combined into one, and the configuration of the multitasking machine 1 can be simplified.

Specifically, the mechanism for moving the electric discharge machining unit 8 and the laser machining unit 9 in the surface direction in the present embodiment includes carriages 6a and 7a, rails 6b and 7b, motors 6c and 7c, an NC control unit 28, and the like. It is In addition, by constructing the relative movement mechanism of the two units as a single movement mechanism of the main carriage 5, the processing matching related between the planar direction movement of the electric discharge machining unit 8 and the planar direction movement of the laser processing unit 9 performance (for example, positioning in the plane direction) can be improved. As a result, machining accuracy between electric discharge machining and laser machining can be improved.

Further, according to this embodiment, the processing table 26 is rotatable about the horizontal first rotation axis (B axis), and furthermore, the attached workpiece W is rotated about the first rotation axis (B axis). It is configured to be rotatable around a vertical second rotation axis (A axis). Therefore, the degree of freedom in setting the orientation of the workpiece W with respect to the laser optical axis (W2-axis direction) of the laser processing unit 9 and the extension direction of the electrode 10a of the electric discharge machining unit 8 (W1-axis direction, Z-axis direction) is improved. do. By changing the direction of the workpiece W instead of changing the direction of the machining head, the machining reference direction for laser machining and electric discharge machining is set to one direction (W1, W2, Z-axis direction), so that each machining can be performed. Accuracy can be improved. Moreover, since the machining reference direction of laser machining and the machining reference direction of electric discharge machining are the same vertical directions (W1, W2, Z-axis directions), the machining accuracy between laser machining and electric discharge machining can be improved.

The multi-tasking machine 1 of this embodiment further includes a deflection detector 12e for detecting whether or not the electrode 10a, which is moved vertically downward along the axial direction during electrical discharge machining, is deflected. . For this reason, it is possible to quickly discover an electrical discharge machining defect, particularly an electrical discharge machining defect caused by an improper movement of the electrode 10a in the Z-axis direction.

Here, the controller further includes a control unit (control unit 3, NC control unit 28) that stops the electric discharge machining when the deflection detector 12e detects that the electrode 10a is bent during the electric discharge machining. ing. Therefore, when the electrode 10a is not properly moved in the Z-axis direction and causes an electric discharge machining failure, damage to the multi-tasking machine 1 due to further movement of the electrode 10a in the Z-axis direction can be prevented. In addition, by stopping the electric discharge machining when a defective electric discharge machining occurs, it is possible to prevent the defective machining of the work W from continuing further, and it is possible to easily perform re-machining and correction of the work W. .

The multi-tasking machine 1 of the present embodiment also includes a voltage detector 13 that monitors the electric discharge machining voltage applied between the electrode 10a and the workpiece W. As shown in FIG. The multi-tasking machine 1 also includes a control section (control unit 3, NC control unit 28) that detects an electrical discharge machining defect based on the electrical discharge machining voltage measured by the voltage detector 13. FIG. Then, the control unit stops the electric discharge machining when such an electric discharge machining failure is detected. Therefore, by stopping the electric discharge machining when a defective electric discharge machining occurs, it is possible to prevent the defective machining of the work W from continuing further, and it is possible to easily perform re-machining and correction of the work W. .

The multi-tasking machine 1 of this embodiment also includes a current detector 14 that monitors the discharge current flowing between the electrode 10a and the workpiece W during electrical discharge machining. The multi-tasking machine 1 also includes a control section (control unit 3, NC control unit 28) that detects an electrical discharge machining defect based on the electrical discharge current measured by the current detector 14. FIG. Then, the control unit stops the electric discharge machining when detecting the electric discharge machining failure. Therefore, by stopping the electric discharge machining when a defective electric discharge machining occurs, it is possible to prevent the defective machining of the work W from continuing further, and it is possible to easily perform re-machining and correction of the work W. .

Next, a multi-tasking machine 1 according to a second embodiment will be described with reference to FIGS. 11 and 12. FIG. In the above-described first embodiment, the electric discharge machining unit 8 and the laser machining unit 9 are moved relative to the machining table 26 in the horizontal direction (plane direction perpendicular to the axial direction of the electrode 10a). The processing unit 9 was horizontally moved. In this embodiment, the machining table 26 is horizontally moved to move the electric discharge machining unit 8 and the laser machining unit 9 relative to the machining table 26 in the horizontal direction (plane direction). The configuration other than this relative movement mechanism is the same as or equivalent to the configuration of the first embodiment described above. In addition, about the structure same or equivalent to the structure of 1st embodiment mentioned above, the same code|symbol is attached|subjected and those detailed description is abbreviate|omitted.

The main carriage 5 of this embodiment is fixed to the main unit 2 . The electric discharge machining unit 8 is configured to be movable with respect to the main carriage 5 in the W1 axis direction. The laser processing unit 9 is also configured to be movable with respect to the main carriage 5 in the W2 axis direction. On the other hand, in this embodiment, the machining table 26X rotatable around the A-axis and B-axis is attached to a machining table unit 26XU that is movable in the horizontal direction (plane direction), that is, in the X-axis direction and the Y-axis direction. there is The machining table unit 26XU is fixed on the X-axis carriage 7Xa, and the machining tank 27 is also fixed on the X-axis carriage 7Xa. That is, the machining tank 27 can also move horizontally together with the machining table 26X.

The X-axis carriage 7Xa is movable in the X-axis direction (horizontal direction in FIG. 11) along the X-axis rail 7Xb. Movement of the X-axis carriage 7Xa in the X-axis direction with respect to the X-axis rail 7Xb is performed by an X-axis motor 7c such as an electric servomotor, and the X-axis motor 7c is controlled by the NC control unit 28. The X-axis rail 7Xb is fixed to the Y-axis carriage 6Xa. The Y-axis carriage 6Xa (and the X-axis rail 7Xb) is movable in the Y-axis direction (horizontal direction in FIG. 1) along the Y-axis rail 6Xb. Movement of the Y-axis carriage 6Xa in the Y-axis direction with respect to the Y-axis rail 6Xb is performed by a Y-axis motor 6c such as an electric servomotor, and the Y-axis motor 6c is controlled by the NC control unit . The Y-axis rail 6Xb is fixed to the housing frame of the main unit 2. As shown in FIG.

In the present embodiment as well, the mechanism of relative movement in the horizontal direction (surface direction) of the electric discharge machining unit 8 and the laser machining unit 9 with respect to the machining table 26 (that is, the workpiece W) is different, but calibration and composite machining are performed in the above-described second embodiment. It can be performed in the same manner as in one embodiment. Moreover, the above-described effects brought about by the first embodiment are also brought about by this embodiment.

Further, according to the present embodiment, the processing table 26X is provided so as to be movable in the planar direction (horizontal direction: X-axis direction and Y-axis direction). That is, the relative movement of the electric discharge machining unit 8 (electrode 10a) with respect to the machining table 26X in the planar direction (horizontal direction) is performed by moving the machining table 26X in the planar direction. Similarly, relative movement of the laser processing unit 9 (laser processing head 9H) with respect to the processing table 26X in the planar direction (horizontal direction) is also performed by moving the processing table 26X in the planar direction. Therefore, the mechanism for moving the electric discharge machining unit 8 in the plane direction and the mechanism for relatively moving the laser machining unit 9 in the plane direction with respect to the processing table 26 can be combined into one, and the configuration of the multitasking machine 1 can be simplified.

Specifically, the mechanism for moving the machining table 26 in the plane direction in this embodiment, that is, the mechanism for relatively moving the electric discharge machining unit 8 and the laser machining unit 9 in the plane direction with respect to the machining table 26 includes carriages 6Xa and 7Xa and rails 6Xb. , 7Xb, motors 6c and 7c, an NC control unit 28, and the like. In addition, by constructing the relative movement mechanism of the two units as a single movement mechanism of the processing table 26, the processing matching related between the planar direction movement of the electric discharge machining unit 8 and the planar direction movement of the laser processing unit 9 performance (for example, positioning in the plane direction) can be improved. As a result, machining accuracy between electric discharge machining and laser machining can be improved.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the work W is a turbine blade having a complicated shape with a TBC (insulating layer) formed on the surface thereof, and the work W is laser-machined by the multitasking machine 1 and then subjected to electrical discharge machining. As described above, the multi-tasking machine of the present invention is suitable for multi-tasking of such a work W, and can process various works. Also, the multi-tasking machine of the present invention can use only the function as a fine hole electric discharge machine, or can use only the function as a laser processing machine.

1 [Electrical discharge machining/laser machining] Multitasking machine 3 Control unit (control section)
5 Main Carriage 8 Electric Discharge Machining Unit 9 Laser Machining Unit 9H Laser Machining Head 10a Electrode 12e Deflection Detector 13 Voltage Detector 14 Current Detector 25 Distance Sensor 26 Machining Table 28 NC Control Unit (Control Unit)
A A axis (second rotation axis)
BB axis (first rotation axis)
X X-axis direction (surface direction: horizontal direction)
Y Y-axis direction (surface direction: horizontal direction)
Z Z-axis direction (axis direction of electrode 10a: vertical direction)
W1 W1 axial direction (axial direction: vertical direction)
W2 W2 axial direction (axial direction: vertical direction)

Claims (8)

A small-hole electric discharge machining/laser processing combined machine for performing small-hole electric discharge machining and laser machining on a work,
a processing table on which the workpiece is attached;
A discharge having a rod-like electrode movably directed in the axial direction of the electrode toward the work mounted on the machining table and relatively movable in a plane direction perpendicular to the axial direction with respect to the machining table a processing unit;
a laser processing unit that has a laser processing head that emits a laser beam toward the work attached to the processing table and that is relatively movable in the planar direction with respect to the processing table;
A small-hole electric discharge machining/laser machining combined processing machine, wherein the laser machining unit is provided with a distance sensor for measuring a distance to the workpiece. 2. The small hole electric discharge machining according to claim 1, wherein said electric discharge machining unit and said laser machining unit are provided movably in said axial direction on a main carriage movable in said surface direction with respect to said machining table.・Laser processing compound processing machine. 2. The small hole electric discharge machining/laser machining combined machine according to claim 1, wherein said machining table is provided movably in said surface direction with respect to said electric discharge machining unit and said laser machining unit. The processing table is rotatable about a first horizontal axis of rotation, and the workpiece attached thereto is rotatable about a second axis of rotation perpendicular to the first axis of rotation, The fine hole electric discharge machining/laser machining combined machine according to any one of claims 1 to 3. The fine hole electric discharge machining according to any one of claims 1 to 4, further comprising a deflection detector that detects whether or not deflection occurs in the electrode moved in the axial direction during electric discharge machining.・Laser processing compound processing machine. 6. The small hole electric discharge machining method according to claim 5, further comprising a control unit that stops the electric discharge machining when the deflection detector detects that the electrode is bent during the electric discharge machining. Laser processing compound processing machine. A voltage detector for monitoring the electric discharge machining voltage applied between the electrode and the workpiece; and a control unit for detecting an electric discharge machining defect based on the electric discharge machining voltage measured by the voltage detector. equipped with
7. The fine hole electric discharge machining/laser machining combined machine according to claim 1, wherein the electric discharge machining is stopped when the controller detects the electric discharge machining defect. a current detector that monitors the discharge current flowing between the electrode and the workpiece during electrical discharge machining; and a controller that detects electrical discharge machining defects based on the electrical discharge current measured by the current detector. It also has
The fine hole electric discharge machining/laser machining combined machine according to any one of claims 1 to 7, wherein the electric discharge machining is stopped when the controller detects the electric discharge machining defect.

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