JP2006315177A - Electrodischarge machining control method and electrodischarge machining control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress an eccentricity of an electrode when rotating and a turbulence applied to an inter-electrode control system resulting from a variation in the electric characteristics, and to improve the machining speed by maintaining the machining condition stably. <P>SOLUTION: An electrodischarge machining control device is equipped with: a machining condition sensing part 102 to sense the machining condition of the object to be machined; a difference signal calculation part 105 to calculate the difference between the sensed value of the machining condition sensing part and the target value for the machining condition; a control amount calculation part 106 to calculate the control amount of the electrode from the calculated difference and a given command value to the electrode; a correction amount calculating part to calculate the correction amount for the eccentricity when the electrode rotates; a control amount correcting part 1102 to correct the control amount with the calculated correction amount; and an electrode driving part (electrode driving device) 109 to move the electrode in the prescribed direction according to the corrected control amount emitted from the control amount correcting part and rotate around a rotary shaft perpendicular to the surface confronting the object machined. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric discharge machining control method and an electric discharge machining control device that perform machining by arranging an electrode and a workpiece in a machining fluid and applying a voltage between the electrode and the workpiece to generate electric discharge. .

  In an electric discharge machine that places an electrode and a workpiece in the machining fluid, applies a voltage between them, and generates electric discharge to perform machining, the distance between the electrode and the workpiece to maintain a stable machining state An inter-electrode control system for adjusting the angle is configured. FIG. 16 is a diagram showing a configuration of a machining control system including a conventional gap control system described in, for example, “Electric discharge machining mechanism and 100% utilization method” (Technical Review), P88-90. In the figure, 101 is an electric discharge machining process, 102 is a machining state discharge unit, 104 is a target value setting capital, 105 is a difference signal calculation unit, 106 is a control amount calculation unit, 107 is a machining locus setting unit, and 108 is a rotation condition setting unit. 109 is an electrode driving device (electrode driving unit), 110 is a machining pulse condition setting unit, and 111 is a machining power source. Further, y is a state quantity of the electric discharge machining process 101, ym is a detection value of the state quantity y detected by the machining state detection unit 102, r is a target value of the machining state set by the target value setting unit 104, and e is A difference signal obtained from the detected value ym and the target value r by the difference signal calculation unit 105, Rv is a machining locus command value set by the machining locus setting unit 107, and Rr is a rotation command set by the rotation condition setting unit 108. Value, Up is a control amount obtained from the difference signal e and the machining locus command value Rv by the control amount calculation unit 106, Mp is an electrode operation amount operated by the electrode driving device 109 based on the control amount Up and the rotation command value Rr, Rs is a machining pulse condition command value set by the machining pulse condition setting unit 110, and Ms is a machining pulse operation amount operated by the machining power source 111 based on the command value Rs. The machining trajectory command value Rv, the control amount Up are vector amounts corresponding to the XYZ axes, the rotation command value Rr is a vector amount corresponding to the rotation speed and the rotation direction of the C axis, and the electrode driving device 109 is an XYZ axis driving device and C This is a shaft rotating device, and the distance between the electrodes is controlled in the XYZ axis directions while rotating the electrodes in the C axis direction by the electrode operation amount Mp. The machining pulse condition command value Rs includes an open voltage, a peak current, a pulse on time, a pulse off time, and the like.

  FIG. 17 is a diagram showing the operation contents of a conventional inter-pole control system. The inter-space control algorithm is generally executed by software processing using a microcomputer, and the k-th processing is shown in the figure. S201 is a process of the machining state detection unit 102, and detects the machining state of the electric discharge machining process, for example, as an average electrode voltage ym (k). S401 is a process of the difference signal calculation unit 105, and a difference signal e (k) is obtained from the target value r of the average electrode voltage and the detected value ym (k). S1701 is a process of the control amount calculation capital 106, and a control amount Up (k) is obtained from the machining locus command value Rv set by the machining locus setting unit 107 and the difference signal e (k), and the control amount Up ( k) is commanded to the electrode driving device 109. Kp is a proportional gain, and Ki is an integral gain. The electrode is operated so that the detected value ym (k) matches the target value r by generally known PI compensation (proportional + integral compensation).

FIG. 18 is a diagram showing a state of a power spectrum of a machining state detection value in a conventional gap control system. In other words, a machining state detection unit 102 when machining is performed by an electric discharge machine having a conventional gap control system. The power spectrum P of the average interelectrode voltage ym (k) detected by the above is obtained. In the figure, peaks of the power spectrum can be confirmed at frequencies f ₁ , f ₂ and f ₃ , which correspond to the rotation frequency of the electrode and its harmonics. These power spectrum peaks are due to the eccentricity of the electrode due to the rotation of the electrode and the fluctuation of the electrical characteristics at the power supply brush portion.

FIG. 19 is a diagram showing a state of a power spectrum of a machining state detection value in another electric discharge machine using a conventional gap control system, that is, machining by another electric discharge machine having a conventional gap control system. The power spectrum P of the inter-electrode average voltage ym (k) detected by the machining state detection unit 102 at the time of performing is obtained. Compared with that of FIG. 18, a peak of the power spectrum appears at the frequency f ₄ . This corresponds to the resonance frequency of the mechanical system of the XYZ axis drive device. Therefore, when there are a plurality of resonance frequencies of the mechanical system, peaks of the power spectrum appear at a plurality of frequencies correspondingly. In this way, the occurrence of several peaks in the detected power spectrum of the average open-circuit voltage means that there is a disturbance to the inter-pole control system at the frequency having the peak, and processing is stable at that frequency. This indicates that the state cannot be maintained.

  When machining while rotating the electrode as described above, the eccentricity of the electrode causes a variation in the distance between the electrodes, resulting in a disturbance to the distance control system, resulting in a problem that the machining speed is reduced. . The machining current is supplied to the electrode from the machining power supply via the power supply brush. However, the fluctuation in the electrical characteristics at the power supply brush due to the rotation of the electrode becomes a disturbance to the inter-pole control system, which reduces the machining speed. There was a problem of inviting. Furthermore, when the electrode drive device has mechanical resonance, the amount of control to the drive device and the actual movement of the electrode are different, making it impossible to control to an appropriate distance between the electrodes, making machining unstable, and reducing the machining speed. There was a problem of inviting.

  This invention has been made to solve the above-mentioned problems, and can suppress disturbance to the inter-electrode control system caused by electrode eccentricity and electrical characteristic fluctuation during electrode rotation, and can be stably processed. An object of the present invention is to obtain a control method and a control apparatus that improve the machining speed by maintaining the above.

  The electric discharge machining control method according to the present invention is an electric discharge machining in which an electrode and a workpiece are arranged in a machining liquid so as to face each other with a predetermined gap and a voltage is applied to the gap to generate an electric discharge to machine the workpiece. In the method, the processing state of the workpiece is detected, the difference between the detected value of the processing state and the target value of the processing state is calculated, the control amount of the electrode is calculated from the difference and the command value of the commanded electrode, Calculate the correction amount to correct the eccentricity during the rotation of the electrode, correct the control amount by the correction amount, move the electrode in a predetermined direction by the corrected control amount, and rotate perpendicular to the surface facing the workpiece It is characterized by being rotated about an axis.

  An electric discharge machining control apparatus according to the present invention is an electric discharge machining apparatus that disposes an electrode and a workpiece in a machining liquid so as to face each other with a predetermined gap and applies a voltage to the gap to generate an electric discharge to machine the workpiece. , A machining state detection unit for detecting the machining state of the workpiece, a difference signal calculation unit for calculating a difference between a detection value of the machining state detection unit and a target value of the machining state, and a command of the electrode commanded as the difference A control amount calculation unit for calculating the control amount of the electrode from the value, a correction amount calculation unit for calculating a correction amount for correcting the eccentricity amount during rotation of the electrode, and a control amount correction unit for correcting the control amount by the correction amount And an electrode driving unit that moves the electrode in a predetermined direction according to the corrected control amount output from the control amount correcting unit and rotates about a rotation axis perpendicular to the surface facing the workpiece. And

  According to the electric discharge machining control method according to the present invention, it is possible to suppress disturbance to the inter-electrode control system due to electrode eccentricity and electrical characteristic fluctuation during electrode rotation, and machining can be performed by maintaining a stable machining state. Control methods that improve speed can be obtained.

  According to the electric discharge machining control device according to the present invention, it is possible to suppress disturbance to the inter-electrode control system due to electrode eccentricity and electrical characteristic fluctuation during electrode rotation, and machining by maintaining a stable machining state. A control device that improves speed can be obtained.

Embodiment 1 FIG.
FIGS. 1-1 and 1-2 are a block diagram and a perspective view of coordinates representing an electric discharge machining control system according to the first embodiment of the present invention. In the figure, reference numerals 101, 102, and 104 to 111 are the same as those shown in the conventional example. Further, the state quantity y, the detection value ym, the machining state target value r, the difference signal e, the machining locus command value Rv, the rotation condition command value Rr, the control amount Up, the electrode operation amount Mp, the machining pulse condition command value Rs, the machining The meaning of the pulse operation amount Ms is the same as that shown in the conventional example. Reference numeral 103 denotes a notch filter unit, and yf denotes a filtered signal obtained by filtering the detected value ym by the notch filter unit 103. FIGS. 2-1 and 2-2 are a flowchart and a circuit diagram showing the operation contents of the inter-pole control system shown in FIGS. 1-1 and 1-2. The figure shows the k-th software processing when the gap control algorithm is realized by a microcomputer. S201 is a process of the machining state detection unit 102, and detects the machining state of the electric discharge machining process as, for example, the open average voltage ym (k). S202 is processing of the notch filter unit 103, and the detection value ym (k) is filtered by the filter F (z ^-1 ) to obtain the signal yf (k). The filter F (z ⁻¹ ) is composed of one or more filters having notch filter characteristics. The notch frequency of the filter is one corresponding to the rotation frequency of the electrode, one corresponding to the resonance frequency of the mechanical system of the XYZ axis drive device, or one corresponding to the rotation frequency of the electrode and a harmonic of the rotation frequency. Corresponding to the rotation frequency of the electrode and the resonance frequency of the mechanical system of the XYZ axis drive device, corresponding to the rotation frequency of the electrode, the harmonic of the rotation frequency, and the resonance frequency of the mechanical system of the XYZ axis drive device Or two or more of those corresponding to two or more resonance frequencies of the mechanical system of the XYZ-axis drive device.

  S203 is a process of the difference signal calculation unit 105, and the difference signal e (k) is obtained from the target value r of the average electrode voltage and the filtered signal yf (k). S204 is a process of the control amount calculation unit 106, which performs integration + proportional compensation on the difference multiple e (k) to obtain a signal u (k). The signal u (k) is supplied to the machining locus setting unit 107. The control amount Up (k) is obtained by multiplying the set machining locus command value Rv. If Up (k) = (up_x (k), up_y (k), up_z (k)) and Rv = (rv_x, rv_y, rv_z), the control amount Up (k) is expressed by the following equation (1). ) (2) (3). The obtained control amount Up (k) is given to the electrode driving device 109. Here, Kp is a proportional gain, and Ki is an integral gain.

As described above, by filtering the detection value of the machining state, the eccentricity of the electrode due to the rotation of the electrode, the fluctuation of the electrical characteristics of the power supply brush part, and the resonance of the machine system of the drive device act as disturbances on the inter-pole control system. It is possible to suppress this.
Although the above has been described with respect to the case where the software is treated, it may be configured as shown in FIG.
In Figure 1-1, P ₁ to P ₃ is an operational amplifier, R ₁ to R ₅ are resistors, C ₁ -C ₃ is a capacitor, these elements constitute a notch filter.
The notch frequency f _N of the notch filter can be determined by the following equations (4) to (6).

For example, if the electrode is rotating at 1000 rpm,
C ₁ = C ₃ = 0.22 μF, C ₂ = 2C ₁ = 0.44 μF,
R ₁ = R ₃ ≈43.4 KΩ, R ₂ = 1 / 2R ₁ ≈21.7 KΩ
Therefore, the notch frequency is f _N ≈16.7 Hg from the above.

Embodiment 2. FIG.
FIG. 3 shows an electric discharge machining control system according to the second embodiment. In the figure, reference numerals 101 to 111 are the same as those shown in the first embodiment of the present invention. Further, the state quantity y, the detection value ym, the machining state target value r, the difference signal e, the machining locus command value Rv, the rotation condition command value Rr, the control amount Up, the electrode operation amount Mp, the machining pulse condition command value Rs, the machining The meaning of the pulse operation amount Ms is the same as that shown in the first embodiment. ef is a signal obtained by filtering the difference signal e by the notch filter unit 103. FIG. 4 is a diagram showing the operation contents of the inter-pole control system shown in FIG. The figure shows the k-th software processing when the gap control algorithm is realized by a microcomputer. S201 is the processing of the machining state detection capital 102, which is the same as that shown in the first embodiment. S401 is a process of the difference signal calculation unit 105, and a difference signal e (k) is obtained from the target value r and the detection value ym (k) of the average voltage between the electrodes. S402 is processing of the notch filter unit 103, and the signal ef (k) is obtained by filtering the difference signal e (k) with the filter F (z ⁻¹ ). The filter F (z ⁻¹ ) is composed of one or more filters having notch filter characteristics. S403 is processing of the control amount calculation unit 106, which performs integration + proportional compensation on the signal ef (k) to obtain the signal u (k), and is set in the processing locus setting unit 107 for the signal u (k). The control amount Up (k) is obtained by multiplying the machining locus command value Rv. Here, Kp is a proportional gain, and Ki is an integral gain.

In the above embodiment, the difference signal e (k) is filtered by the filter F (z ⁻¹ ) to obtain the signal ef (k). However, instead of filtering the difference signal e (k), FIG. After obtaining the control amount Up (k) = (up_x (k), up_y (k), up_z (k)) as shown in FIG. 6, filtering may be performed on each control amount. That is, as shown in S501, filtering is performed on up_x (k), up_y (k), and up_z (k), and up_x (k), up_y (k), and up_z (k) are set as the control amount to the XYZ axis driving device. To do. Here, the filter F (z ⁻¹ ) is composed of one or more filters having notch filter characteristics.

When the frequency of the notch filter of the notch filter unit is the resonance frequency of the electrode or workpiece drive device, the control amount Up (k) = instead of filtering the difference signal e (k). After obtaining (up_x (k), up_y (k), up_z (k)), only the control amount of the axis having resonance may be filtered. For example, S601 in FIG. 6 shows a case where the X 紬 drive device has resonance, and filtering is performed on up (k), and up_xf (k) is set as a control amount for the X-axis drive device. Here, the filter G (z ⁻¹ ) is composed of one or more filters having notch filter characteristics.

As described above, by filtering the difference signal e (k) or the control amount Up (k), the eccentricity of the electrode due to the electrode rotation, the electric characteristic variation of the power supply brush, and the resonance of the mechanical system of the driving device are extremely large. It becomes possible to suppress acting as a disturbance on the intermediate control system. In addition, for the resonance of the mechanical system, by filtering only the control amount of the axis having the resonance, it is possible to avoid the occurrence of unnecessary phase delay in the inter-pole control, and the stability of the inter-pole control system Is advantageous in terms of sex.
In the above, the case where software processing is performed has been described, but it may be configured by dedicated hardware.

Embodiment 3 FIG.
FIG. 7 is a diagram illustrating an electric discharge machining control system according to the third embodiment. In the figure, reference numerals 101, 102, 104 to 111 are the same as those shown in the first embodiment of the present invention. Also, the state quantity y, the detected value ym, the filtered yf, the machining state target value r, the difference signal e, the machining locus command value Rv, the rotation condition command value Rr, the control amount Up, the electrode operation amount Mp, and the machining pulse condition command The meanings of the value Rs and the machining pulse manipulated variable Ms are the same as those shown in the first embodiment of the present invention. Reference numeral 701 denotes a variable notch filter unit, and reference numeral 702 denotes a notch frequency automatic adjustment unit. The variable notch filter unit 701 realizes notch filter characteristics having the notch frequency obtained by the notch frequency automatic adjustment unit 702, and obtains the signal yf by filtering the detected value ym. FIG. 8 shows k-th software processing in the variable notch filter unit 701 and the notch frequency automatic adjustment unit 702. In S801, the rotation condition command value Rr set by the rotation condition setting unit 108 and the resonance frequency of the drive device that has been examined in advance are read. In S802, the notch frequency is obtained based on the read information. In S803, the notch frequency is obtained. Based on this, the notch frequency of the variable notch filter is adjusted.

By laying down as described above, the notch frequency can be adjusted in accordance with changes in the rotation conditions and the like, and an appropriate filter song can always be realized.
In the above embodiment, the notch frequency automatic adjustment unit 702 obtains the notch frequency based on the rotation condition command value Rr set by the rotation condition setting unit 108 and the resonance frequency of the drive device that has been examined in advance, and the variable notch Although the notch frequency of the filter unit is adjusted, as shown in FIG. 9, the notch frequency automatic adjusting unit 901 takes the detected value ym, obtains the power spectrum of the detected value ym, and determines the power spectrum. The frequency having a peak in the distribution may be obtained, and the notch frequency of the variable notch filter unit may be adjusted based on the frequency. FIG. 10 shows k-th software processing in the variable notch filter unit 701 and the notch frequency automatic adjustment unit 901. In S1001, the detected value ym is captured. In S1002, the power spectrum of the detected value ym is calculated. In S1003, a frequency having a peak in the power spectrum is obtained. In S803, the frequency is adjusted as a notch frequency, and the frequency of the variable notch filter unit is adjusted. I do.

By configuring as described above, it is not necessary to check the resonance frequency of the mechanical system in advance, it is not necessary to check the rotation condition, and even when they change, the notch frequency is automatically adjusted accordingly. Can always achieve proper filtering.
In the above description, the case where filtering is performed on the detection value ym has been described, but the same configuration can be adopted when filtering is performed on the difference signal e or on the control amount of the driving device.
In the above, the case where software processing is performed has been described, but it may be configured by dedicated hardware.

Embodiment 4 FIG.
FIG. 11 is a diagram illustrating an electric discharge machining control system according to the fourth embodiment of the present invention. In the figure, reference numerals 101, 102, 104 to 111 are the same as those shown in the first embodiment of the present invention. Further, the state quantity y, the detection value ym, the machining state target value r, the difference signal e, the machining locus command value Rv, the rotation condition command value Rr, the control amount Up, the electrode operation amount Mp, the machining pulse condition command value Rs, the machining The meaning of the pulse operation amount Ms is the same as that shown in the first embodiment of the present invention. 1101 is a correction amount calculation unit, 1102 is a control amount correction unit, θ is an actual electrode rotation angle, Cp is a correction amount obtained by the correction amount calculation unit 1101 based on the rotation angle θ, and Upc is a control This is a control amount to the electrode driving device 109 obtained by correcting the amount Up by the correction amount Cp.

  Now, in the processing performed while rotating the cylindrical electrode, consider the case where the electrode center is different from the electrode rotation center and the electrode is eccentric. In FIG. 12, reference numeral 1201 denotes a cylindrical electrode having an electrode radius of r_e and an electrode center of Oe (x_Oe, y_Oe), and rotates at the rotation center O (0, 0). When the electrode is rotated twice and the state of eccentricity is observed at the intersection point p with the x-axis, the stationary component is removed as shown in FIG. In the figure, r_oe is the distance between the electrode center Oe and the rotation center O.

FIG. 14 is a diagram illustrating the k-th software processing in the correction amount calculation unit 1101 and the control amount correction unit 1102 in FIG. In S1401, it is determined whether data for correcting the eccentricity of the electrode is already present. If the correction data is not available, the process proceeds to S1402, and the relationship between the rotation angle θ of the electrode and the displacement L at the point P is measured. In S1403, r_oc is obtained from the measurement result. In S1404, it is determined whether or not the displacement L is first reduced when the electrode is rotated to 0 or 360 °. If it does not decrease, the process proceeds to S1406 and θmax at which the displacement L is maximized is obtained, and φ = −θmax is set. On the other hand, when it decreases, it progresses to S1406 and calculates | requires (theta) min from which the displacement amount L becomes the minimum, and it is set as (phi) = (theta) min = -180 degree. As described above, r_oc and φ are obtained. These processes are performed after the electrodes are attached and before actual processing. Therefore, during processing, it is determined that the correction data is held in S1401, and the process proceeds to S1407, where the rotation angle θ is detected. In S1408, a correction amount Cp = (cp_x (k), cp_y (k)) is obtained from the detected rotation angle θ (k), r_oc, and φ. In step S1409, the control amount Upc is obtained by correcting the control amount Up with the correction amount Cp. The control amount Up is obtained by the same method as in the conventional example.
By configuring as described above, the actual eccentricity of the electrode can be actually measured, and the eccentricity can be corrected only by changing the signal processing by using a conventional electrode driving device based on the actual measurement value. It becomes possible to stabilize the state.
Note that the method of obtaining r_oe and φ is not limited to the above description, and it is possible to correct the same electrode eccentricity even if it is obtained by other methods.

  In the above embodiment, the eccentricity correction data is obtained by the mathematical expression using r_oe and φ. However, the data table for the eccentricity correction is constructed from the measurement data of FIG. The control amount Upc may be obtained by referring to the data table based on the above.

Embodiment 5. FIG.
FIG. 15 is a diagram showing an electric discharge machining control system according to the fifth embodiment of the present invention. In the figure, 101, 102, 104 to 111 are the same as those shown in the first embodiment of the present invention, and 1101 is the same as that shown in the fourth embodiment of the present invention. Further, the state quantity y, the detection value ym, the machining state target value r, the difference signal e, the machining locus command value Rv, the rotation condition command value Rr, the control amount Up, the electrode operation amount Mp, the machining pulse condition command value Rs, the machining The meaning of the pulse operation amount Ms is the same as that shown in the first embodiment of the present invention, and the meaning of the electrode rotation angle θ and the correction amount Cp is the same as that shown in the fourth embodiment of the present invention. is there. Reference numeral 1501 denotes an eccentricity correction drive device, and the electrode operation amount Mpc is obtained by adding the electrode operation amount based on the electrode operation amount Mp by the electrode drive device 109.

  Next, the operation will be described. The same correction amount calculation unit 1101 as in the fourth embodiment obtains the correction amount Cp, and the correction amount is given as a control amount of the eccentricity correction drive device 1501. That is, in addition to the electrode driving device 109, the amount of eccentricity of the electrode is corrected by an eccentricity correction driving device 1501 that can drive the electrode in a relatively small range in the XY axis direction.

  In the conventional electrode driving device, a high-speed response is difficult because the electrode driving range is large, but in the eccentricity correction driving device, the driving is in a delicate range, and high-speed response is easy to be realized. Therefore, by configuring as described above, it is possible to accurately correct the eccentricity of the electrode even when the electrode is rotated at a high speed. In addition, it can be realized relatively easily because signal processing for correcting eccentricity is performed independently of signal processing of a conventional inter-pole control system.

  In the above embodiments, the eccentricity correction drive device is a device that can be driven in a relatively small range in the XY axis direction. However, even if the coordinate axes of the electrode drive device and the eccentricity correction drive device are different, the coordinate relationship between them is different. If it is clear, it is possible to correct the eccentric amount of the electrode without any problem by performing coordinate conversion on the correction amount Cp.

  The present invention is applied to an electric discharge machining apparatus, and suppresses disturbance to an inter-electrode control system due to electrode eccentricity and electrode drive system mechanical resonance during electrode rotation, and is effective in improving machining speed by machining stabilization. is there.

It is a block diagram which shows the electric discharge machining control system of Embodiment 1 of this invention. It is a perspective view which shows the electric discharge machining control system coordinate of Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the gap control system shown to FIGS. 1-2. FIG. 2 is a diagram corresponding to FIG. 2A and configured by dedicated hardware. It is a block diagram which shows the electric discharge machining control system which is Embodiment 2 of this invention. It is a flowchart which shows operation | movement of the gap control system shown in FIG. It is a flowchart which shows operation | movement of the other gap control system of Embodiment 2 of this invention. It is a flowchart which shows operation | movement of the other gap control system of Embodiment 2 of this invention. It is a block diagram which shows the electric discharge machining control system of Embodiment 3 of this invention. It is a figure which shows the automatic adjustment operation | movement of the notch frequency of Embodiment 3 of this invention. It is a block diagram which shows the operation | movement of the other gap control system of Embodiment 3 of this invention. It is a figure which shows the automatic adjustment operation | movement of the notch frequency of Embodiment 3 of this invention. It is a block diagram which shows the electric discharge machining control system of Embodiment 4 of this invention. It is a figure which shows the case where the electrode center of Embodiment 4 of this invention differs from the rotation center of an electrode. It is a figure which shows the mode of eccentricity observed when the electrode of Embodiment 4 of this invention is rotated. FIG. 12 is a flowchart showing the Kth software processing of the correction calculation unit and the control amount correction unit in FIG. 11. It is a block diagram which shows the electric discharge machining control system of Embodiment 5 of this invention. It is a block diagram which shows the structure of the process control system containing the conventional gap | interval control system. It is a flowchart which shows the operation | movement content of the conventional gap control system. It is a figure which shows the mode of the power spectrum of the processing state detection value in the conventional gap control system. It is a figure which shows the mode of the power spectrum of the machining state detection value in the other electric discharge machine using the conventional gap control system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 102 Processing state detection part 103 Notch filter part 105 Difference signal calculating part 106 Control amount calculating part 109 Electrode drive device (electrode drive part)
701 Notch filter unit 702, 901 Notch frequency automatic adjustment unit 1102 Control amount correction unit

Claims (4)

In the electric discharge machining method of processing the workpiece by generating an electric discharge by applying a voltage to the gap and arranging the electrode and the workpiece facing each other with a predetermined gap in the machining liquid,
Detecting the machining state of the workpiece,
Calculate the difference between the detected value of the machining state and the target value of the machining state,
Calculate the control amount of the electrode from the difference and the command value of the commanded electrode,
Calculate the correction amount to correct the eccentricity during electrode rotation,
Correcting the control amount by the correction amount;
An electric discharge machining control method characterized in that the electrode is moved in a predetermined direction by the corrected control amount and rotated around a rotation axis perpendicular to the surface facing the workpiece. In the electric discharge machining method of processing the workpiece by generating an electric discharge by applying a voltage to the gap and arranging the electrode and the workpiece facing each other with a predetermined gap in the machining liquid,
Detecting the machining state of the workpiece,
Calculate the difference between the detected value of the machining state and the target value of the machining state,
Calculate the control amount of the electrode from the difference and the command value of the commanded electrode,
Calculate the correction amount to correct the eccentricity during electrode rotation,
The electrode is moved in a predetermined direction by the control amount while the electrode is driven in the XY axis direction to correct the eccentricity of the electrode by the correction amount, and is rotated around a rotation axis perpendicular to the surface facing the workpiece. An electrical discharge machining control method characterized in that the electrical discharge machining is performed. In an electrical discharge machining apparatus for processing the workpiece by generating an electric discharge by applying a voltage to the gap and disposing the electrode and the workpiece facing each other with a predetermined gap in the machining fluid,
A machining state detection unit for detecting a machining state of the workpiece;
A difference signal calculation unit for calculating a difference between a detection value of the machining state detection unit and a target value of the machining state;
A control amount calculation unit that calculates the control amount of the electrode from the difference and the command value of the commanded electrode;
A correction amount calculation unit for calculating a correction amount for correcting the eccentric amount during rotation of the electrode;
A control amount correction unit for correcting the control amount by the correction amount;
An electrode driving unit that moves the electrode in a predetermined direction according to the corrected control amount output from the control amount correction unit and rotates the electrode about a rotation axis that is perpendicular to the surface facing the workpiece. An electric discharge machining control device. In an electrical discharge machining apparatus for processing the workpiece by generating an electric discharge by applying a voltage to the gap and disposing the electrode and the workpiece facing each other with a predetermined gap in the machining fluid,
A machining state detection unit for detecting a machining state of the workpiece;
A difference signal calculation unit for calculating a difference between a detection value of the machining state detection unit and a target value of the machining state;
A control amount calculation unit that calculates the control amount of the electrode from the difference and the command value of the commanded electrode;
A correction amount calculation unit for calculating a correction amount for correcting the eccentric amount during rotation of the electrode;
An eccentricity correction driving unit that drives the electrodes in the XY-axis directions for correcting the eccentricity of the electrodes according to the correction amount from the correction amount calculation unit;
An electrode driving unit configured to move the electrode in a predetermined direction according to the control amount output from the control amount calculation unit and to rotate about a rotation axis perpendicular to a surface facing the workpiece. Electric discharge machining control device.

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