Control device for wire electric discharge machine and control method for wire electric discharge machine

Abstract

The present invention relates to a control device for a wire electric discharge machine that performs taper machining, the control device comprising: a first storage unit that stores a first machining condition corresponding to a first inclination angle of a wire electrode; a second storage unit that stores a second processing condition corresponding to a second inclination angle of the wire electrode; and a machining condition calculation unit that calculates a third machining condition corresponding to a third inclination angle of the wire electrode on the basis of first angle information indicating the first inclination angle, second angle information indicating the second inclination angle, the first machining condition, and the second machining condition.

Description

Technical Field

[0001] The present invention relates to a control device for a wire electrical discharge machine and a control method for a wire electrical discharge machine. Background Art

[0002] In wire EDM, taper machining, where the wire electrode is tilted, results in more unstable discharge compared to machining with the wire electrode held vertically. Consequently, the risk of wire breakage is known to be higher during taper machining. Existing wire EDM machines (e.g., Japanese Patent Application Publication No. 2007-83372) are equipped with processing conditions for taper machining. Summary of the Invention

[0003] Conventional wire electric discharge machines have a problem in that, when a workpiece has a tapered shape, machining is performed under machining conditions suitable for tapered machining, resulting in a prolonged machining time.

[0004] A first embodiment of the present invention is a control device for a wire electrical discharge machine, which causes a wire electrode to move relative to a processing object and performs electrical discharge processing on the processing object by generating an electric discharge between the wire electrode and the processing object. The control device for the wire electrical discharge machine includes: a first storage unit that stores a first processing condition corresponding to a first inclination angle of the wire electrode; a second storage unit that stores a second processing condition corresponding to a second inclination angle of the wire electrode; and a processing condition calculation unit that calculates a third processing condition corresponding to a third inclination angle of the wire electrode based on first angle information indicating the first inclination angle, second angle information indicating the second inclination angle, the first processing condition, and the second processing condition.

[0005] A second embodiment of the present invention is a control method for a wire electrical discharge machine, which causes a wire electrode to move relative to a processing object and performs electrical discharge processing on the processing object by generating an electric discharge between the wire electrode and the processing object. The control method for the wire electrical discharge machine includes: a first storage step of storing a first processing condition corresponding to a first inclination angle of the wire electrode in a first storage unit; a second storage step of storing a second processing condition corresponding to a second inclination angle of the wire electrode in a second storage unit; and a calculation step of calculating, by a processing condition calculation unit, a third processing condition corresponding to a third inclination angle of the wire electrode based on first angle information representing the first inclination angle, second angle information representing the second inclination angle, the first processing condition, and the second processing condition. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 It is a perspective view showing a configuration example of the wire electrical discharge machine according to the first embodiment. Figure 2 Yes Figure 1 The diagram shows the structure of the control device and its control. Figure 3 Yes Figure 2 Flowchart of the operation of the processing condition calculation unit. Figure 4 This is an explanatory diagram of an example of calculation of the inclination angle of the wire electrode and machining conditions. Figure 5 This is a flowchart showing the operation of the processing condition calculation unit according to the second embodiment. DETAILED DESCRIPTION

[0007] Conventional wire EDM machines set taper machining conditions based on the wire electrode's maximum tilt angle, where discharge is most likely to become unstable, during taper machining. Consequently, even when the wire electrode's tilt angle is small, machining is performed under taper machining conditions set at the maximum machining angle, resulting in increased machining time.

[0008] (First embodiment) like Figure 1 As shown, the wire EDM 10 applies a voltage between the electrodes formed by the wire electrode 12 and the object W to generate discharge, thereby performing EDM on the object W. The wire EDM 10 moves the wire electrode 12 relative to the object W along a path specified by a predetermined program. The relative movement between the wire electrode 12 and the object W is achieved by moving the stage 14 supporting the object W in the X and Y directions. Figure 1 The X direction, Y direction, and Z direction shown are orthogonal to each other, and the -Z direction is the direction of gravity.

[0009] The wire discharge machine 10 includes an upper wire guide 16, a lower wire guide 18, an upper guide block 20, and a lower guide block 22. The upper wire guide 16 supports the wire electrode 12 on the upper side (+Z direction side) of the stage 14, and the lower wire guide 18 supports the wire electrode 12 on the lower side (-Z direction side) of the stage 14. The upper wire guide 16 is mounted on the upper guide block 20, and the lower wire guide 18 is mounted on the lower guide block 22. The upper wire guide 16 and the upper guide block 20 move relative to the lower wire guide 18 in the U direction and the V direction. The U direction is the same as the X direction, and the V direction is the same as the Y direction. The U direction and the V direction are used to represent the movement of the upper wire guide 16.

[0010] The wire electrode 12 is fed from the bobbin 24 in the feeding direction at a predetermined speed. The wire electrode 12 is fed by the upper roller 25a located between the bobbin 24 and the upper guide block 20, and the lower roller 25b located between the lower guide block 22 and the wire recovery box 27. The upper roller 25a and the lower roller 25b are Figure 2The wire electrode 12 is driven by a feed drive unit 26. The feed drive unit 26 includes a motor for rotating the upper roller 25a and a motor for rotating the lower roller 25b. The difference in rotational speed between the upper roller 25a and the lower roller 25b generates a predetermined wire tension on the wire electrode 12. The feed drive unit 26 controls the tension according to processing conditions.

[0011] Furthermore, the wire electrical discharge machine 10 includes a machining power supply 28 that supplies voltage to the inter-electrode gap, a control device 30 , a machining tank 32 , and a bed 34 .

[0012] Figure 1 The machining tank 32 shown can also store machining fluid. In this case, the stage 14, the workpiece W, the upper guide 16 and upper guide block 20, and the lower guide 18 and lower guide block 22 are immersed in the machining fluid. The machining tank 32 is provided on the bed 34.

[0013] like Figure 2 As shown, the wire EDM 10 further includes a feed drive unit 26, an upper guide drive unit 36, a displacement drive unit 40, and an electrode pin 42. The displacement drive unit 40 drives the stage 14 to move the wire electrode 12 relative to the workpiece W in the X and Y directions. The displacement drive unit 40 includes a motor for moving the stage 14 in the X direction (X motor) and a motor for moving the stage 14 in the Y direction (Y motor). The displacement drive unit 40 moves the stage 14 along a path specified by a predetermined machining program. The displacement drive unit 40 controls the movement speed of the stage 14 based on the servo gain and set voltage specified by the machining conditions.

[0014] The upper guide drive unit 36 ​​drives the upper guide block 20. The upper guide drive unit 36 ​​tilts the wire electrode 12 by moving the upper wire guide 16 relative to the lower wire guide 18 in the U and V directions. The upper guide drive unit 36 ​​includes a motor (U motor) for moving the upper guide block 20 in the U direction and a motor (V motor) for moving the upper guide block 20 in the V direction. The U motor and the V motor each include an encoder (rotational position detection sensor) for detecting the rotational position. The detection value of the encoder represents the amount of movement of the upper wire guide 16. In other words, it represents the relative displacement of the upper wire guide 16 and the lower wire guide 18 in the UV plane. By using the detection value of the encoder and the distance between the upper wire guide 16 and the lower wire guide 18 in the Z direction, information related to the angle of the wire electrode 12 (third angle information) is obtained using the inverse trigonometric function (arctan).

[0015] like Figure 2As shown, the electrode pin 42 is in contact with the wire electrode 12. This allows the machining power supply 28 to apply a voltage to the electrode pin 42 and the workpiece W, and consequently, to the gap between the electrodes. The machining power supply 28 applies a pulse voltage specified by machining conditions between the wire electrode 12 and the workpiece W. The machining power supply 28 controls the rest period between the application of the pulse voltage based on the machining conditions.

[0016] The control device 30 includes a processing circuit 310 and a memory 320 storing a program. The processing circuit 310 executes the program, thereby functioning as the control device 30 of this embodiment. The control device 30 controls the machining of the object W by the wire electrical discharge machine 10. The memory 320 includes volatile memory such as RAM and nonvolatile memory such as ROM and flash memory. The processing circuit 310 includes a processor such as a CPU.

[0017] The control device 30 functions as a process control unit 311 and a process condition calculation unit 312 by executing a program on a processing circuit 310. At least a portion of the process control unit 311 and the process condition calculation unit 312 may be implemented by an ASIC, FPGA, or other integrated circuit.

[0018] The processing control unit 311 controls the displacement drive unit 40, the upper guide drive unit 36, the feed drive unit 26, and the processing power supply 28 based on the processing program and processing conditions. The processing control unit 311 controls the feed drive unit 26 based on the processing conditions to generate the wire tension specified by the processing conditions in the wire electrode 12. The processing control unit 311 controls the displacement drive unit 40 based on the processing program and processing conditions to move the wire electrode 12 relative to the processing object W. The processing control unit 311 controls the processing power supply 28 based on the processing conditions to apply a voltage between the electrodes.

[0019] The memory 320 includes a first storage unit 321 and a second storage unit 322. The first storage unit 321 and the second storage unit 322 store machining conditions. The first storage unit 321 stores first machining conditions corresponding to first angle information of the wire electrode 12, and the second storage unit 322 stores second machining conditions corresponding to second angle information of the wire electrode 12.

[0020] The first angle information is, for example, information regarding the maximum inclination angle (first inclination angle) at which the wire electrode 12 is tilted to perform tapered machining on the object W. In other words, the first machining conditions are machining conditions corresponding to the object W to be machined. The inclination angle of the wire electrode 12 is the angle between the wire electrode 12 and the Z direction. In this embodiment, the first angle information directly uses the value of the first inclination angle. The first angle information is pre-set to, for example, 15° or 30°.

[0021] The second angle information is information regarding the second inclination angle of the wire electrode 12. In this embodiment, the second angle information uses the value of the second inclination angle. The second inclination angle is smaller than the first inclination angle and is set to 0°, for example. In this case, the second machining condition is a machining condition when no taper machining is performed.

[0022] The machining conditions, such as the first machining condition and the second machining condition, include setting items such as the discharge rest time, applied voltage, voltage application time, servo gain, set voltage, and wire tension. The discharge rest time specifies the rest time (pulse interval) when the machining power supply 28 applies the discharge voltage (pulse) between the wire electrode 12 and the machining object W. The voltage application time specifies the application time (pulse width) of the discharge voltage (pulse). The applied voltage specifies the voltage value (pulse height) of the discharge voltage (pulse). The servo gain specifies the responsiveness of the displacement drive unit 40 to the command value. The larger the servo gain, the better the responsiveness to the command value of the displacement drive unit 40. The set voltage is the target voltage value during machining. The smaller the set voltage, the narrower the gap between the wire electrode 12 and the machining object W during machining. The wire tension specifies the tension applied to the wire electrode 12. For example, the wire tension is determined by the difference in rotational speed between the motor of the upper roller 25a and the motor of the lower roller 25b of the feed drive unit 26.

[0023] The first machining condition is determined and set experimentally to achieve the maximum machining speed within a range where the discharge of the wire electrode 12 is stable and uninterrupted at a first inclination angle. The first machining condition can be set based on the type of wire electrode 12 and the thickness (dimension in the Z direction) of the machining object W. Similarly, the second machining condition is determined and set experimentally to achieve the maximum machining speed within a range where the discharge of the wire electrode 12 is stable and uninterrupted at a second inclination angle. The second machining condition can be set based on the type of wire electrode 12 and the thickness (dimension in the Z direction) of the machining object W. Since the first inclination angle is larger than the second inclination angle (0°), the machining speed under the first machining condition is slower than that under the second machining condition. Furthermore, the machining speed is determined by the inter-electrode voltage between the wire electrode 12 and the machining object W.

[0024] The processing condition calculation unit 312 obtains third angle information related to the current inclination angle of the wire electrode 12. The processing condition calculation unit 312 obtains the third angle information based on the information of the encoder provided in the upper guide drive unit 36. The processing condition calculation unit 312 calculates the third processing condition corresponding to the third angle information and applies it to the processing control unit 311. In this embodiment, the processing condition calculation unit 312 calculates the third processing condition based on the first angle information, the second angle information, the first processing condition, and the second processing condition. The third processing condition achieves a faster processing speed than the first processing condition. In this way, since the third processing condition is calculated based on the current inclination of the wire electrode 12, the wire electrode 12 is prevented from being broken and the processing speed is increased compared to the case where processing is performed only under the first processing condition.

[0025] Hereinafter, the operation of the wire electric discharge machine 10 will be described.

[0026] When machining begins, the machining control unit 311 controls the wire EDM 10 to begin machining the object W. The wire electrode 12 begins machining the object W at the second inclination angle of 0°. When performing tapered machining, the machining control unit 311 begins machining using the initially set first machining conditions. The machining condition calculation unit 312 adjusts the machining conditions based on the current inclination angle (third inclination angle) of the wire electrode 12 relative to the first machining conditions.

[0027] The processing control unit 311 changes the inclination angle of the wire electrode 12 as processing progresses. The processing control unit 311 changes the inclination angle of the wire electrode 12 by displacing the upper wire guide 16. The processing condition calculation unit 312 adjusts the processing conditions of the processing control unit 311 based on the current inclination angle (third inclination angle) of the wire electrode 12. The following describes the adjustment of processing conditions by the processing condition calculation unit 312.

[0028] like Figure 3 As shown, when machining begins, the machining condition calculation unit 312 proceeds to step S10. In step S10, the machining condition calculation unit 312 determines whether automatic adjustment of machining conditions is set to ON. If automatic adjustment of machining conditions is not set (automatic adjustment is OFF) ("No" in step S10), the machining condition calculation unit 312 terminates the process. If automatic adjustment is OFF, the machining control unit 311 performs electrical discharge machining according to the first machining conditions.

[0029] If automatic adjustment of machining conditions is set to ON ("YES" in step S10), the process proceeds to step S12. In step S12, the machining condition calculation unit 312 reads the first machining conditions from the first storage unit 321 and simultaneously reads the first angle information. In this embodiment, the first angle information is the value of the first inclination angle of the wire electrode 12.

[0030] Next, in step S14, the machining condition calculation unit 312 reads the second machining condition and the second angle information from the second storage unit 322. In this embodiment, the second angle information is the value of the second inclination angle (0°) of the wire electrode 12, and the second machining condition is the machining condition when taper machining is not performed.

[0031] Next, in step S16, the processing condition calculation unit 312 reads the range of the tilt angle to be adjusted from the memory 320. The range of the tilt angle is a range of angles obtained by dividing the tilt angle between the second tilt angle and the first tilt angle into multiple angles. For example, when the second tilt angle is 30°, the range of the tilt angle can be as follows: Figure 4 In the example shown in the figure, the interval range includes a first interval of 0°<inclination angle ≤ 10°, a second interval of 10°<inclination angle ≤ 20°, and a third interval of 20°<inclination angle ≤ 30°.

[0032] Then, in Figure 3 In step S18, the machining condition calculation unit 312 obtains third angle information related to the current inclination angle of the wire electrode 12. The machining condition calculation unit 312 calculates the current inclination angle of the wire electrode 12 based on information from the encoder of the upper guide drive unit 36 ​​and the distance between the upper wire guide 16 and the lower wire guide 18 in the Z direction. The distance between the upper wire guide 16 and the lower wire guide 18 in the Z direction is known.

[0033] Next, in step S20 , the machining condition calculation unit 312 determines to which section range read in step S16 the current inclination angle (third angle information) of the wire electrode 12 obtained in step S18 belongs.

[0034] Next, in step S22, the machining condition calculation unit 312 calculates machining conditions (third machining conditions) corresponding to the third angle information based on the determined interval range. The machining control unit 311 performs electrical discharge machining according to the third machining conditions.

[0035] Here, the processing condition calculation unit 312 calculates the processing condition (fourth processing condition) corresponding to the maximum inclination angle in the interval to which the third inclination angle belongs, detected in step S18, as the third processing condition. The reason for calculating the third processing condition for each interval is to reduce the frequency of calculation of the third processing condition and to reduce the processing load of the processing circuit 310. In addition, the processing condition corresponding to the larger inclination angle of the wire electrode 12 makes it more difficult for the wire electrode 12 to break, so the processing condition corresponding to the largest angle in the interval is calculated as the third processing condition. In addition, the processing condition calculation unit 312 can also calculate the processing condition corresponding to the current inclination angle as the third processing condition. In this case, steps S16 and S20 are unnecessary.

[0036] The processing condition calculation unit 312 calculates the processing conditions corresponding to the third angle information based on a predetermined relational expression. This relational expression is obtained based on the relationship between the first tilt angle, the first processing condition, the second tilt angle, and the second processing condition. This relational expression will be described later.

[0037] Next, in step S24, the processing condition calculation unit 312 determines whether the automatic adjustment is set to ON. If it is determined that the automatic adjustment is set to ON ("Yes"), the process returns to step S18. In step S24, if it is determined that the automatic adjustment is set to OFF ("No"), the processing condition calculation unit 312 ends. Figure 3 In this case, the machining control unit 311 performs the electric discharge machining according to the first machining condition.

[0038] Next, the relational expression used in the calculation of the third processing condition is explained. Figure 4 In this example, the first machining condition is when the first inclination angle is 30°. The discharge rest time under the first machining condition is 40, the servo gain is 100, and the wire tension is 800. Furthermore, the second machining condition is when the second inclination angle is 0°. The discharge rest time under the second machining condition is 10, the servo gain is 400, and the wire tension is 1100.

[0039] The processing condition calculation unit 312 calculates the third processing condition using the relational expression of the linear polynomial of the inclination angle.

[0040] The discharge rest time of the third machining condition can be obtained from the following relational expression (1). The discharge rest time of the third processing condition = (the discharge rest time of the first processing condition) - A × {(the first inclination angle - the second inclination angle) - (the third inclination angle - the second inclination angle) ... (1) In the relational expression (1), the variable A represents the change in the discharge rest time per 1° tilt angle. Figure 4 In the example, variable A is 1. If we substitute Figure 4 The first inclination angle, the second inclination angle, the value of the discharge rest time at the first inclination angle, and the value of the variable A are expressed as the following formula (2). Discharge rest time of the third machining condition = 40 - 1 × (30 - third inclination angle) (2) Therefore, when the third tilt angle is 20°, the discharge rest time is 30, and when the third tilt angle is 10°, the discharge rest time is 20 (refer to Figure 4 ).

[0041] The applied voltage of the third processing condition can be obtained from the following relational expression (3). The applied voltage of the third processing condition = (the applied voltage of the first processing condition) + B × {(the first inclination angle - the second inclination angle) - (the third inclination angle - the second inclination angle)} ... (3) In equation (3), variable B is the change in applied voltage per 1° tilt angle. Figure 4 In the example, variable B is 1. Figure 4 Substituting the first tilt angle, the second tilt angle, the value of the applied voltage at the first tilt angle, and the value of the variable B into the relational expression (3) yields the following equation (4). The applied voltage of the third processing condition = 10 + 1 × (30 - third inclination angle) (4) Therefore, when the third tilt angle is 20°, the applied voltage is 20, and when the third tilt angle is 10°, the applied voltage is 30 (refer to Figure 4 ).

[0042] The voltage application time of the third processing condition can be obtained from the following relational expression (5). Voltage application time of the third processing condition = (voltage application time of the first processing condition) + C × {(first inclination angle - second inclination angle) - (third inclination angle - second inclination angle)} ... (5) In equation (5), the variable C is the change in voltage application time per 1° tilt angle. Figure 4 In the example, the variable C is 1. Figure 4 Substituting the first tilt angle, the second tilt angle, the voltage application time at the first tilt angle, and the value of the variable C into the relational expression (5) yields the following equation (6). Voltage application time of the third processing condition = 10 + 1 × (30 - third inclination angle) (6) Therefore, when the third inclination angle is 20°, the voltage application time is 20, and when the third inclination angle is 10°, the voltage application time is 30.

[0043] The set voltage of the third processing condition can be obtained from the following relational expression (7). The setting voltage of the third processing condition = (the setting voltage of the first processing condition) - D × {(the first inclination angle - the second inclination angle) - (the third inclination angle - the second inclination angle)} ... (7) In equation (7), the variable D is the change in the set voltage per 1° tilt angle. Figure 4 In the example, the variable D is 1. Figure 4 Substituting the first tilt angle, the second tilt angle, the value of the setting voltage of the first tilt angle, and the value of the variable D into the relational expression (7), the following equation (8) is obtained. The setting voltage of the third processing condition = 40-1×(30-third inclination angle) (8) Therefore, when the third inclination angle is 20°, the voltage is set to 30, and when the third inclination angle is 10°, the voltage is set to 20.

[0044] The servo gain of the third processing condition can be calculated from the following relational expression (9). Servo gain of the third machining condition = (servo gain of the first machining condition) + E × {(first inclination angle - second inclination angle) - (third inclination angle - second inclination angle)} (9) In equation (9), variable E is the change in servo gain per 1° tilt angle. If we substitute Figure 4 The first tilt angle, the second tilt angle, the value of the servo gain for the first tilt angle, and the value of the variable E (in Figure 4 10), then the following formula is obtained. Servo gain of the third machining condition = 100 + 10 × (30 - third inclination angle) (10) Therefore, when the third tilt angle is 20°, the servo gain is 200, and when the third tilt angle is 10°, the servo gain is 300 (refer to Figure 4 ).

[0045] The line tension of the third processing condition can be calculated from the following relational expression (11). Wire tension of the third processing condition = (wire tension of the first processing condition) + F × {(first inclination angle - second inclination angle) - (third inclination angle - second inclination angle)} ... (11) In equation (11), the variable F is the change in line tension per 1° tilt angle. If we substitute Figure 4 The first tilt angle, the second tilt angle, the line tension of the first tilt angle and the value of the variable F (in Figure 4 10), then the following formula is obtained. The line tension of the third processing condition = 800 + 10 × (30 - the third inclination angle) ... (12) Therefore, when the third inclination angle is 20°, the wire tension is 900, and when the third inclination angle is 10°, the wire tension is 1000 (refer to FIG. Figure 4 ).

[0046] Furthermore, according to the above-mentioned equations (1) to (12), when the third inclination angle is equal to the second inclination angle, the third processing condition becomes the same value as the second processing condition. Therefore, when the third inclination angle is equal to the second inclination angle, the processing condition calculation unit 312 calculates the second processing condition as the third processing condition.

[0047] The processing condition calculation unit 312 applies the third processing condition calculated as described above to the processing conditions of the processing control unit 311. Figure 4 In the example shown, when the third inclination angle of the wire electrode 12 is 0°, processing is performed under the second processing condition with emphasis on speed. In addition, in the first interval where the third inclination angle is 0°<inclination angle ≤10°, processing is performed under the processing condition corresponding to the inclination angle of 10°. The processing speed of this processing condition is faster than the first processing condition and slower than the second processing condition. In addition, in the second interval where the third inclination angle is 10°<inclination angle ≤20°, processing is performed under the processing condition corresponding to the inclination angle of 20°. The processing condition of this second interval is also faster than the processing speed of the first processing condition, but slower than the processing speed of the processing condition of the first interval. Furthermore, in the interval where 20°<inclination angle ≤30° (first inclination angle), processing is performed under the first processing condition corresponding to the inclination angle of 30° (first inclination angle).

[0048] As described above, the control device 30 of the wire EDM 10 of this configuration example can further increase the machining speed compared to the conventional technology by adjusting the machining conditions according to the inclination angle of the wire electrode 12. Since there is no need to set machining conditions for each inclination angle of the wire electrode 12, the machining condition setting work is unnecessary.

[0049] In addition, in this embodiment, the interval for adjusting the processing conditions is not limited to Figure 4 The example of 10° may also be a finer interval (for example, less than 1°).

[0050] (Modification of the first embodiment) This modification involves Figure 3 Another configuration example of the method for calculating the processing condition corresponding to the third inclination angle by the processing condition calculation unit 312 in step S22. In this modification, the processing condition is obtained based on the ratio of the first angle difference to the second angle difference.

[0051] The first angle difference is a value obtained by subtracting the second inclination angle from the first inclination angle. The second angle difference is a value obtained by subtracting the third inclination angle from the first inclination angle. The processing condition calculation unit 312 calculates the second angle difference based on the third inclination angle.

[0052] Next, the machining condition calculation unit 312 calculates the machining conditions using a relational expression represented by the ratio of the first angle difference to the second angle difference. In this case, the discharge rest time is obtained by the following relational expression (13). Discharge rest time = discharge rest time of the first machining condition - G × (second angle difference / first angle difference) (13) In equation (13), the variable G is the change in the discharge rest time relative to the first angle difference. Figure 4 In the example of , it is 30. The processing condition calculation unit 312 calculates the discharge rest time by substituting the ratio of the first angle difference to the second angle difference (second angle difference / first angle difference) into the above relational expression.

[0053] In addition, the applied voltage is obtained from the following relational expression (14). Applied voltage = applied voltage of the first processing condition + H × (second angle difference / first angle difference) (14) In equation (14), the variable H is the change in applied voltage for each first angle difference. Figure 4 In the example, it is 30.

[0054] In addition, the voltage application time is obtained from the following relational expression (15). Voltage application time = voltage application time of the first processing condition + I × (second angle difference / first angle difference) (15) In equation (15), the variable I is the change in voltage application time for each first angle difference. Figure 4 In the example, it is 30.

[0055] In addition, the set voltage is obtained from the following relational expression (16). Setting voltage = Setting voltage of the first processing condition + J × (second angle difference / first angle difference) (16) In equation (16), the variable J is the change in the set voltage for each first angle difference. Figure 4 In this case, it is 30.

[0056] In addition, the servo gain is obtained from the following relational expression (17). Servo gain = servo gain of the first machining condition + K × (second angle difference / first angle difference) (17) In equation (17), the variable K is the change in servo gain for each first angle difference. Figure 4 In this case, it is 300.

[0057] In addition, the line tension is obtained from the following relational expression (18). Line tension = Line tension of the first processing condition + L × (second angle difference / first angle difference) (18) In equation (18), the variable L is the change in line tension for each first angle difference. Figure 4 In this case, it is 300.

[0058] The processing condition calculation unit 312 calculates the third processing condition by substituting the ratio of the first angle difference to the second angle difference (second angle difference / first angle difference) into the above-mentioned relational expressions (13) to (18).

[0059] The third machining condition corresponding to the third inclination angle is obtained through the above processing. According to the machining condition calculation unit 312 of this modification, the machining speed can be increased compared to the conventional technology.

[0060] According to the wire electric discharge machine 10 of the first embodiment described above, when performing taper machining, machining conditions can be adjusted according to the inclination angle of the wire electrode 12. Therefore, the wire electric discharge machine 10 can perform taper machining more quickly.

[0061] (Second embodiment) This embodiment relates to another configuration example of machining condition adjustment performed by the machining condition calculation unit 312. In this embodiment, the machining condition calculation unit 312 uses the relative movement amount between the upper guide block 20 and the lower guide block 22 as angle information related to the inclination angle of the wire electrode 12. In this embodiment, since the configuration of each component of the wire electrical discharge machine 10 remains unchanged, a detailed description of the configuration will be omitted.

[0062] like Figure 5 As shown, the processing condition calculation unit 312 determines whether the automatic adjustment of the processing conditions is ON (turned on) in step S30. Figure 3 The same as step S10.

[0063] In step S32, the processing condition calculation unit 312 reads the first angle information and the first processing condition from the first storage unit 321. Figure 3The first angle information of the present embodiment is the displacement amount of the upper guide block 20 corresponding to the maximum tilt angle of the wire electrode 12 during machining of the object W (encoder information of the upper guide drive unit 36 ​​).

[0064] Next, in step S34, the processing condition calculation unit 312 reads the second angle information and the second processing condition from the second storage unit 322. Figure 3 The second angle information of the present embodiment is the displacement amount of the upper guide block 20 corresponding to the inclination angle of 0° of the wire electrode 12 (encoder information of the upper guide drive unit 36 ​​).

[0065] Next, in step S36, the machining condition calculation unit 312 reads the range of angle information (displacement amount) for adjusting the machining conditions from the memory 320. The range of angle information (displacement amount) is obtained by dividing the interval between the displacement amount of the upper guide block 20 corresponding to the second angle information and the displacement amount of the upper guide block 20 corresponding to the first angle information into a plurality of ranges.

[0066] Next, in step S38 , the machining condition calculation unit 312 acquires the current displacement of the upper guide block 20 as third angle information.

[0067] Next, in step S40 , the processing condition calculation unit 312 determines the interval range to which the third angle information belongs.

[0068] Next, in step S42 , the processing condition calculation unit 312 calculates the third processing condition according to the interval range to which the third angle information belongs, and applies the third processing condition to the processing control unit 311 .

[0069] The machining condition calculation unit 312 calculates the third machining condition based on a predetermined relational expression. The relational expression is calculated as a linear polynomial of the displacement amount with respect to the machining condition, based on the relationship between the displacement amount corresponding to the first angle information, the displacement amount corresponding to the second angle information, and the first and second machining conditions.

[0070] Here, the processing condition calculation unit 312 calculates the processing condition corresponding to the maximum relative movement amount in the section to which the third angle information belongs. The processing condition calculation unit 312 applies the processing condition calculated as described above to the processing condition of the processing control unit 311.

[0071] Then, in step S44, the processing condition calculation unit 312 determines whether automatic adjustment is on. If it is determined that automatic adjustment is on ("Yes"), the process returns to step S38. If it is determined that automatic adjustment is off ("No") in step S44, the processing condition calculation unit 312 ends the process.

[0072] The control device 30 of the wire EDM machine 10 in the second embodiment described above adjusts machining conditions based on the relative movement of the upper and lower wire guides 16 and 18, rather than the inclination angle of the wire electrode 12. Specifically, the control device 30 can adjust machining conditions based on encoder information from the upper guide block 20, without calculating the inclination angle of the wire electrode 12. Therefore, in this embodiment, the processing of the machining condition calculation unit 312 can be simplified.

[0073] The above-mentioned embodiments may be modified as follows. In the following modifications, descriptions overlapping with those of the embodiment are omitted.

[0074] The first inclination angle may not be the maximum inclination angle during machining of the object W, but may be any inclination angle of the wire electrode 12. For example, the first inclination angle may be the maximum inclination angle of the wire electrode 12 permitted by the wire EDM 10. Furthermore, the second inclination angle is not limited to 0° and may be any angle. In this case, an approximate function (e.g., a linear polynomial) is calculated based on the first inclination angle, the second inclination angle, the first machining condition, and the second machining condition to provide machining conditions corresponding to the arbitrary inclination angle (the third inclination angle), and the third machining condition is calculated based on this approximate function.

[0075] Alternatively, the first and second inclination angles may be the same angle. In this case, the third processing condition can be obtained by adding or multiplying the first processing condition at the first inclination angle by a variable that changes according to the third inclination angle.

[0076] The above-described embodiments enable automatic application of machining conditions with a higher machining speed to any tilt angle of the wire electrode 12 during taper machining using the wire electric discharge machine 10 , thereby contributing to faster taper machining.

[0077] The following supplementary notes are also disclosed regarding the above-mentioned embodiment.

[0078] (Note 1) The wire discharge machining machine (10) of the present invention moves a wire electrode (12) relative to a machining object (W) and performs discharge machining on the machining object by generating discharge between the wire electrode and the machining object. The control device (30) of the wire discharge machining machine (10) includes: a first storage unit (321) that stores a first machining condition corresponding to a first inclination angle of the wire electrode; a second storage unit (322) that stores a second machining condition corresponding to a second inclination angle of the wire electrode; and a machining condition calculation unit (312) that calculates a third machining condition corresponding to a third inclination angle of the wire electrode based on first angle information indicating the first inclination angle, second angle information indicating the second inclination angle, the first machining condition, and the second machining condition.

[0079] (Note 2) In the control device of the wire electrical discharge machine described in Supplement 1, the machining condition calculation unit may calculate the third machining condition from the first angle information, the second angle information, the first machining condition, and the second machining condition based on a predetermined relational expression.

[0080] (Note 3) In the control device of the wire discharge machine recorded in Note 2, the processing condition calculation unit calculates the third processing condition using the prescribed relationship using the ratio of the second angle difference to the first angle difference, and the first angle difference can be the angle difference information obtained by subtracting the second angle information from the first angle information, and the second angle difference can be the angle difference information obtained by subtracting the third angle information from the first angle information.

[0081] (Note 4) In the control device of the wire electrical discharge machine according to any one of Appendixes 1 to 3, the first processing condition may be a processing condition corresponding to the maximum inclination angle of the wire electrode in processing the processing object, and the second processing condition may be a processing condition corresponding to the second inclination angle being 0°.

[0082] (Note 5) In the control device of the wire electrical discharge machine described in Appendix 4, the inclination angle of the wire electrode can also be divided into multiple intervals at predetermined angular intervals, and the processing condition calculation unit can calculate the fourth processing condition corresponding to the maximum inclination angle in the interval to which the third inclination angle belongs.

[0083] (Note 6) In the control device for a wire electrical discharge machine according to any one of Supplementary Notes 1 to 5, the third inclination angle may be greater than or equal to the second inclination angle and less than or equal to the first inclination angle.

[0084] (Note 7) In the control device of a wire discharge machine described in any one of Notes 1 to 6, the wire discharge machine comprises: an upper wire guide (16) and a lower wire guide (18) which clamp the processing object and support the wire electrode; and a driving mechanism which moves the upper wire guide and the lower wire guide relative to each other in order to tilt the wire electrode, and the first angle information and the second angle information may also be information indicating the relative movement amount of the upper wire guide and the lower wire guide.

[0085] (Note 8) The control method of a wire electric discharge machine of the present invention is a control method of a wire electric discharge machine in which a wire electrode is moved relative to a processing object and discharge is generated between the wire electrode and the processing object, thereby performing electric discharge processing on the processing object. The control method of the wire electric discharge machine includes: a first storage step of storing a first processing condition corresponding to a first inclination angle of the wire electrode in a first storage unit; a second storage step of storing a second processing condition corresponding to a second inclination angle of the wire electrode in a second storage unit; and a calculation step of calculating a third processing condition corresponding to a third inclination angle of the wire electrode by a processing condition calculation unit based on first angle information representing the first inclination angle, second angle information representing the second inclination angle, the first processing condition, and the second processing condition.

[0086] (Note 9) In the control method of the wire electrical discharge machine described in Appendix 8, the processing condition calculation unit may calculate the third processing condition based on a predetermined relationship expression and in accordance with the first angle information, the second angle information, the first processing condition, and the second processing condition.

[0087] (Note 10) In the control method of the wire discharge machine recorded in Note 9, the processing condition calculation unit calculates the third processing condition using the prescribed relationship using the ratio of the second angle difference to the first angle difference. The first angle difference can be the angle difference information obtained by subtracting the second angle information from the first angle information, and the second angle difference can be the angle difference information obtained by subtracting the third angle information from the first angle information.

[0088] (Note 11) In the control method of a wire electrical discharge machine according to any one of appendices 8 to 10, the first processing condition may be a processing condition corresponding to a maximum inclination angle of the wire electrode in processing the object, and the second processing condition may be a processing condition corresponding to the second inclination angle being 0°.

[0089] (Note 12) In the control method of the wire electrical discharge machine described in Supplement 11, the inclination angle of the wire electrode may be divided into a plurality of intervals at predetermined angular intervals, and the machining condition calculation unit may calculate a fourth machining condition corresponding to the maximum inclination angle in the interval to which the third inclination angle belongs.

[0090] (Note 13) In the control method of a wire electrical discharge machine according to any one of Supplementary Notes 8 to 12, the third inclination angle may be greater than or equal to the second inclination angle and less than or equal to the first inclination angle.

[0091] (Note 14) In the control method of a wire discharge machine as described in any one of Notes 8 to 13, the wire discharge machine comprises: an upper wire guide and a lower wire guide, which clamp the processing object and support the wire electrode; and a driving mechanism, which causes the upper wire guide and the lower wire guide to move relative to each other in order to tilt the wire electrode, and the first angle information and the second angle information may also be information indicating the relative movement amount of the upper wire guide and the lower wire guide.

[0092] Although the present invention has been described in detail, the present invention is not limited to the above-mentioned embodiments. These embodiments may be added, replaced, changed, partially deleted, etc., without departing from the scope of the present disclosure, or without departing from the scope of the present disclosure derived from the contents recorded in the technical solution and its equivalents. In addition, these embodiments may also be implemented in combination. For example, in the above-mentioned embodiment, the order of each action and the order of each processing are shown as an example and are not limited to this. In addition, the use of numerical values ​​or mathematical formulas in the description of the above-mentioned embodiment is also not limited to this. Explanation of symbols

[0093] 10…Wire EDM 12…Wire Electrode 16...Upper wire guide 18...Lower wire guide 30 ...control device 312 ...processing condition calculation unit 321 ...first storage unit 322 ...second storage unit.

Claims

1. A control device for a wire electrical discharge machine, wherein the wire electrical discharge machine moves a wire electrode relative to an object to be processed and discharges the object by generating an electric discharge between the wire electrode and the object, the control device comprising: a first storage unit storing a first machining condition corresponding to a first inclination angle of the wire electrode; a second storage unit storing a second machining condition corresponding to a second inclination angle of the wire electrode; and A machining condition calculation unit calculates a third machining condition corresponding to a third inclination angle of the wire electrode based on first angle information indicating the first inclination angle, second angle information indicating the second inclination angle, the first machining condition, and the second machining condition.

2. The control device for a wire electric discharge machine according to claim 1, wherein: The processing condition calculation unit calculates the third processing condition from the first angle information, the second angle information, the first processing condition, and the second processing condition based on a predetermined relational expression.

3. The control device for a wire electric discharge machine according to claim 2, wherein: The processing condition calculation unit calculates the third processing condition using the predetermined relational expression using the ratio of the second angular difference to the first angular difference. The first angle difference is angle difference information obtained by subtracting the second angle information from the first angle information, and the second angle difference is angle difference information obtained by subtracting the third angle information from the first angle information.

4. The control device for a wire electric discharge machine according to any one of claims 1 to 3, wherein: The first processing condition is a processing condition corresponding to a maximum inclination angle of the wire electrode during processing of the object to be processed. The second processing condition is a processing condition corresponding to the second inclination angle being 0°.

5. The control device for a wire electric discharge machine according to claim 4, wherein: The inclination angle of the wire electrode is divided into a plurality of intervals at predetermined angle intervals. The machining condition calculation unit calculates a fourth machining condition corresponding to a maximum inclination angle in a section to which the third inclination angle belongs.

6. The control device for a wire electric discharge machine according to any one of claims 1 to 5, wherein: The third inclination angle is greater than or equal to the second inclination angle and less than or equal to the first inclination angle.

7. The control device for a wire electrical discharge machine according to any one of claims 1 to 6, wherein: The wire discharge machine includes: an upper wire guide and a lower wire guide that sandwich the object to be processed and support the wire electrode; and a drive mechanism that relatively moves the upper wire guide and the lower wire guide to tilt the wire electrode. The first angle information and the second angle information are information indicating the relative movement amount between the upper and lower wire guides.

8. A method for controlling a wire electrical discharge machine, wherein the wire electrical discharge machine moves a wire electrode relative to an object to be processed and discharges the object by generating an electric discharge between the wire electrode and the object, the method comprising: a first storing step of storing a first processing condition corresponding to a first inclination angle of the wire electrode in a first storage unit; a second storing step of storing a second processing condition corresponding to a second inclination angle of the wire electrode in a second storage unit; as well as The calculation step calculates, by a processing condition calculation unit, a third processing condition corresponding to a third inclination angle of the wire electrode based on first angle information indicating the first inclination angle, second angle information indicating the second inclination angle, the first processing condition, and the second processing condition.

9. The control method of a wire electric discharge machine according to claim 8, wherein: The processing condition calculation unit calculates the third processing condition from the first angle information, the second angle information, the first processing condition, and the second processing condition based on a predetermined relational expression.

10. The control method of a wire electrical discharge machine according to claim 9, wherein: The processing condition calculation unit calculates the third processing condition using the predetermined relational expression using the ratio of the second angular difference to the first angular difference. The first angle difference is angle difference information obtained by subtracting the second angle information from the first angle information, and the second angle difference is angle difference information obtained by subtracting the third angle information from the first angle information.

11. The method for controlling a wire electrical discharge machine according to any one of claims 8 to 10, wherein: The first processing condition is a processing condition corresponding to a maximum inclination angle of the wire electrode during processing of the object to be processed. The second processing condition is a processing condition corresponding to the second inclination angle being 0°.

12. The control method of a wire electrical discharge machine according to claim 11, wherein: The inclination angle of the wire electrode is divided into a plurality of intervals at predetermined angle intervals. The machining condition calculation unit calculates a fourth machining condition corresponding to a maximum inclination angle in a section to which the third inclination angle belongs.

13. The control method of a wire electrical discharge machine according to any one of claims 8 to 12, characterized in that: The third inclination angle is greater than or equal to the second inclination angle and less than or equal to the first inclination angle.

14. The control method of a wire electrical discharge machine according to any one of claims 8 to 13, characterized in that: The wire discharge machine includes: an upper wire guide and a lower wire guide that sandwich the object to be processed and support the wire electrode; and a drive mechanism that relatively moves the upper wire guide and the lower wire guide to tilt the wire electrode. The first angle information and the second angle information are information indicating the relative movement amount between the upper and lower wire guides.

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