JP3336880B2 - Electric discharge machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric discharge machining apparatus, and more particularly, to an electric discharge machining apparatus for accurately machining a desired shape even when a machining machine body is deformed by machining reaction force during machining.

[0002]

2. Description of the Related Art FIG. 10 is a block diagram of a conventional general electric discharge machine. In the figure, 1 is an electrode, 2 is a workpiece,
Reference numeral 3 denotes a processing liquid, 4 denotes a processing tank, 5 denotes an electrode rotating device that rotates the electrode 1 around the Z axis, 6 denotes a Y-axis table, 7 denotes a Y-axis driving device that drives the Y-axis table 6 in the Y-axis direction, 8 Is an X-axis table, 9 is an X-axis driving device for driving the X-axis table 8 in the X-axis direction, 10 is a Z-axis driving device for driving the electrode rotating device 5 on which the electrode 1 is mounted in the Z-axis direction, and 11 is an electrode 1 A machining power supply for supplying a machining pulse between poles formed by the workpiece and the workpiece 2, a machining state detection device 12 for detecting a machining state during machining, and a machining fluid supply device 13 for supplying a machining fluid to a machining gap. , 14 are NC controllers.

FIG. 11 is a block diagram for explaining the operation of the electric discharge machine shown in FIG. In the figure, 1
1, 12, 13, and 14 are the same as those in FIG. Reference numeral 15 denotes a processing power supply 11, a processing liquid supply device 13, a processing locus commander 16, a jump operation controller 17, and a comparator 1.
A processing condition setting device 8 sets various processing conditions.
Reference numeral 16 denotes a machining locus commander for generating a locus for machining into a desired shape, an electrode swing pattern, and the like; 17 a jump operation controller for raising and lowering the electrode 1 during machining; 18 a comparator; A processing controller 20 is a processing / jump operation switching device. These 15 to 20 are generally controlled by a program of the NC control device 14. Reference numeral 21 denotes an electrode driving device, which includes an electrode rotating device 5, each axis table, and each axis driving device 6 to 10. Reference numeral 22 denotes an electric discharge machining process, which represents an electric discharge machining phenomenon that occurs between the electrode 1 and the workpiece 2 that are arranged to face each other in the machining fluid 3.

Next, the operation will be described. In a general electric discharge machining apparatus, a gap control system that adjusts a gap between the electrode 1 and the workpiece 2 in order to machine a desired shape while maintaining a stable machining state is configured. This control system compares a reference command value set by the machining condition setting device 15 with a detection value indicating the state of the electric discharge machining process 22 detected by the machining state detection device 12 by a comparator 18 to obtain a deviation. An electrode movement command based on a command from the machining trajectory commander 16 is given to the electrode driving device 21 by the controller 19 so that the deviation becomes zero, and the gap between the electrode 1 and the workpiece 2 is controlled.
Then, when the electrode movement command value reaches the final command value of the desired shape, the machining is finished. At this time, the processing is selected in the processing / jump operation switching device 20. The NC control device 14 controls the jump operation together with the above-described gap control. In the jump operation, the machining / jump operation switcher 20 switches from forcible gap control to a jump operation, and performs an ascending and descending operation of the electrode 1.
This jump operation is important in that machining waste is removed from the machining gap by the pump action and the machining state is stabilized.

However, in such an electric discharge machining apparatus, particularly when the electrode is large, when the machining gap is very narrow as in finishing machining, or when the machining depth is deep,
When the electrode is raised or lowered during a jump operation, a large positive pressure or negative pressure (hereinafter referred to as "processing reaction force") acts on the electrode, which deforms the processing machine body and reduces processing accuracy. There is. According to a study by Mori et al. At Toyota Institute of Technology, "Study on Mechanical Characteristics in Actual Operation of Electric Discharge Machine", Journal of the Japan Electrical Machining Society, Vol.20, No.39, p19-p29, 1987 The force is attributed to the viscosity of the working fluid, and the force acting when the electrode descends particularly causes a reduction in working accuracy.

FIG. 12 is an explanatory view showing mechanical characteristics in actual operation of the electric discharge machining apparatus, and shows the main shaft displacement, machining reaction force, and column deformation during the jump operation actually measured by Mori et al. Looking at the portion A in the figure, it can be seen that the processing reaction force becomes maximum when the electrode descends. In the drawings, the main axis indicates the Z-axis, and the column indicates the main body of the processing machine that supports the Z-axis, and the processing reaction force is measured by a force sensor incorporated in an electrode mounting jig.

In order to solve the above-mentioned problems, Mohri et al. Described above made a processing machine by using a portal structure to increase rigidity, or by reducing the electrode descent speed immediately before the descent of the electrode was completed. It proposes to reduce the reaction force and reduce the deformation of the column. Looking at the portion B in FIG. 12, it can be seen that the processing reaction force is smaller than that of the portion A, and therefore, the column deformation amount is also small. This is due to the fact that the speed at which the main shaft descends in section B is lower, and is a result that supports Mori et al.'S proposal.

Japanese Patent Publication No. 4-318 describes a method for controlling the electrode speed during a jump operation based on the same idea.
No. 06 publication. In this method, as shown in FIG. 13, the speed is changed according to the distance between the electrode and the workpiece when the electrode is raised and lowered. FIG. 13 is an explanatory diagram showing electrode moving speed control during a jump operation in the electric discharge machine,
When the distance between the electrode and the workpiece becomes L1 when the electrode is raised, the electrode lifting speed is accelerated from v2 to v1.When the distance between the electrode and the workpiece is L1 when the electrode is lowered, the electrode descend speed is reduced from v1 to v2. The positive and negative pressures acting on the electrodes are reduced.

FIG. 14 is an explanatory view schematically showing a spindle displacement during a jump operation and during machining in an electric discharge machine utilizing the above results. As shown in the figure, the processing and the jump operation are alternately repeated. Processing is performed only for a period determined by the jump-down time Jd. The jump operation includes a jump-up distance Ju and electrode moving speeds V1 and V
2. Control is performed by an electrode moving speed switching point P1 and a jump operation / processing switching point P2. These parameters are set to optimal values according to the processing conditions, or adaptively and automatically set according to the processing state. For example, when performing finishing, the electrode moving speed V2 is set to be much lower than V1. Here, since the processing gap distance at the time of finishing processing is as narrow as 10 to 20 μm, the jump operation / processing switching point P2 is set at a slightly higher position so that the electrode does not collide with the workpiece when the electrode is lowered in the jump operation. I do.

The machining and jumping operations are controlled by the program of the NC controller 14 as described above. The processing procedure will be described with reference to the flowchart shown in FIG. First, in ST1, a processing pulse condition, a jump operation condition, and the like input by an operator are initially set, and "processing" is set as a control mode. Then, the process waits for input of a processing start in ST2, and when the processing start is recognized, the process proceeds to ST3. In ST3, the control mode is checked. As described above, since the control mode is "processing" at first, the process proceeds to ST4. ST
In 4, the processing power is turned on, and the supply of the processing pulse between the electrode and the workpiece is started. Needless to say,
The pulse of the condition set in ST1 is supplied. At the same time, in ST5, a timer is started to measure a predetermined jump down time. ST6 and ST7 are portions that realize the function of the gap control described above, detect the gap voltage, compare the command value with the detected value to obtain a deviation, and generate a machining locus command according to the deviation. An electrode movement command based on the output is output to the electrode driving device. In ST8, it is determined whether or not the current electrode position has reached the final command value, that is, whether or not to finish machining.

For the sake of explanation, assuming that the current electrode position has not yet reached the final command value, the operation proceeds to ST9. In ST9, it is checked whether or not the timer started in ST5 has reached a predetermined jump down time Jd. If the timer does not exceed the predetermined jump down time Jd, the processing of ST6 to ST9 is repeated. If the timer has exceeded the predetermined jump down time Jd, the process proceeds to ST10 and ST11. In ST10 and ST11, in preparation for starting the jump operation, the timer started in ST5 is reset, the control mode is set to "jump operation", and the process returns to ST3. In ST3, the control mode is checked again. Since the control mode is set to “jump operation” in ST11, ST
Proceed to 12. In ST12, the processing power is turned off. Subsequently, in ST13, the electrode moving speed is set to V1. In ST14, the electrode is raised at a speed V1 by a predetermined jump-up distance Ju, and then the electrode is lowered at a speed V1. In ST15, it is checked whether or not the electrode descending at the speed V1 has reached a predetermined electrode descending speed switching point P1, and if it has reached, the electrode moving speed is changed from V1 to V2 in ST16. In ST17, it is checked whether or not the electrode descending at the speed V2 has reached the switching point P2 from the predetermined jump operation to the processing. If it has reached, the control mode is set to "processing" in ST18, and ST3 is set. Return to That is, the jump operation ends. As described above, the processing proceeds while repeating the processing and the jump operation. When it is confirmed in ST8 that the current electrode position has reached the final command value, the processing is terminated in ST19. In the figure, BL1 is ST4 to ST11.
The processing of processing control consisting of ST19, and BL2
This shows the processing of jump operation control consisting of ST18.

By the way, the above-mentioned report by Mohri et al. Describes only an electrode area up to about 20 cm 2. FIG. 16 is an explanatory diagram showing the spindle displacement and the amount of column deformation observed when finishing is performed while performing a jump operation using an electrode having an electrode area of about 400 cm 2. In this jump operation, control is performed so that the electrode descent speed becomes small immediately before the electrode descent is completed. However, a point to be noted in comparison with FIG. 12 is that a large column deformation occurs in the portion C in the machining control period after the end of the jump operation (hereinafter referred to as “under machining”). As can be seen by carefully observing the spindle displacement shown in FIG. 16, the column deformation shown here is such that after switching from the jump operation to the machining, the electrode is moved toward the workpiece until the discharge is generated by the operation of the gap control system. Sent out,
At this time, since the electrode area is large, the reaction force due to the viscosity of the working fluid is not negligible, and the column is deformed in a direction away from the workpiece with the electrode so that the column slides. Also, when the electrode approaches the appropriate machining gap distance and discharges are continuously generated, the machining fluid is vaporized, and the pressure of a number of bubbles generated at that time also acts together with the reaction force due to the viscosity of the machining fluid, It is considered that the column was deformed in a direction away from the workpiece with the electrode so that the column was moved. In this way, when deforming in the direction away from the workpiece with the electrode so that the column slides during processing,
As a result, the working gap is widened, and the electrode is further fed to the workpiece by the action of the gap control system. That is, the electrode position reaches the final command value even though the machining has not actually progressed, and an erroneous machining end determination is performed. Therefore, the problem of the column deformation is not limited to the jump operation, and especially in the case of large-area processing, the column deformation during the processing described here is more than the column deformation during the electrode lifting and lowering described above. Probably a problem.

[0013]

As described above, in the conventional electric discharge machining apparatus, particularly when large area machining is performed under finishing machining conditions, it is sufficient to set the electrode descending speed at the time of the jump operation to a small value to sufficiently deform the column. It is impossible to suppress. Therefore, although the processing machine body is deformed due to the viscosity of the processing liquid or the pressure of the bubbles, the processing is terminated when the electrode position reaches the final command value of a desired shape during the processing. This results in a processing shape error such as finishing to be shallower than the processing depth. Further, additional processing for removing the unprocessed portion is required, which causes a problem that the processing time is increased.

The present invention has been made in order to solve such a problem, and in particular, a working caused by a force generated during working (hereinafter referred to as a "working reaction force" as described above). An object of the present invention is to realize an electric discharge machine which can reduce a shape error and suppress an increase in machining time.

[0015]

According to a first aspect of the present invention, there is provided an electric discharge machining apparatus which supplies a machining fluid to a gap between an electrode and a workpiece, and which has a periodic relative motion to both the electrode and the workpiece. The operation is performed and a machining pulse is supplied to perform electrical discharge machining on the workpiece.The minimum value of the machining period from the return from the jump operation to the start of the next jump operation is determined by the electric discharge.
Based on at least one condition among the area, shape, material, and thickness of the pole
Other than a specified section within the machining period
The coordinate value of the electrode or the workpiece is a predetermined command value
Short circuit occurs when the machine reaches
If not, it is determined that the processing is completed .

According to a second aspect of the present invention, there is provided an electric discharge machining apparatus which supplies a machining fluid to a gap between an electrode and a workpiece to give a jump operation which is a periodic relative motion to both the electrode and the workpiece and a machining pulse. Is supplied to perform EDM on the workpiece, and returns from the jump operation to perform the next jump operation.
The minimum value of the processing period before starting is determined by the area, shape,
Set based on one or more conditions of material and thickness, and
The electrode or the workpiece at the last point in the processing period
Is reached when the coordinate value reaches a predetermined command value, and
Judgment of machining end if no short circuit occurs during machining period
It is something to do.

According to a third aspect of the present invention, there is provided an electric discharge machining apparatus which supplies a machining fluid to a gap between an electrode and a workpiece to give a jump operation which is a periodic relative motion to both the electrode and the workpiece and a machining pulse. The workpiece is subjected to electrical discharge machining, and the minimum value of the machining period from returning from the jump operation to starting the next jump operation is determined by the area, shape,
Set based on one or more conditions of material and thickness, and
Once the coordinate value of the electrode or workpiece is
After reaching the command value, the coordinate value is
The processing is determined to be completed when the command value remains at the command value until the time point .

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a first embodiment of the present invention will be described. FIG. 1 is a flowchart for explaining the operation of the electric discharge machine according to the first embodiment of the present invention. In the figure, individual processing steps ST1 to ST11, ST19 and a processing block BL2 are the same as the conventional one shown in FIG.
ST20 is a processing step for setting a section in which processing end is not determined within the processing period, and ST21 is a processing step for determining whether or not the processing point belongs to a section in which processing end is not determined in the processing period. The configuration of the electric discharge machine according to the present embodiment is the same as that of the conventional apparatus shown in FIG. 10, and a description thereof will be omitted.

This embodiment is characterized by an operation at the time of machining, as compared with the conventional electric discharge machining apparatus. Therefore, the following description will be limited to the machining. First, in ST1, processing pulse conditions, jump operation conditions, control modes, and the like input by an operator are initialized. As described above, the control mode is “processing”. In ST20, a non-determination section in which the completion of processing is not determined within the processing period is set. ST2
Waits for the input of the machining start, and proceeds to ST3 when the machining start is recognized. In ST3, the control mode is checked. Since the control mode is "processing", the process proceeds to ST4. In ST4, the processing power is turned on, and the supply of the processing pulse between the electrode and the workpiece is started. At the same time, in ST5, a timer is started to measure a predetermined jump down time. ST
6, ST7 is a part for realizing the function of the gap control described above, detects the gap voltage, compares the command value with the detected value to determine a deviation, and generates a machining locus command according to the deviation. An electrode movement command based on the output is output to the electrode driving device. Next, ST2
In step 1, it is determined whether or not the processing time belongs to the non-determination section set in ST20. if,
If the processing time is not in the non-determination section, the process proceeds to ST8.
If the processing time is in the non-determination section, the process proceeds to ST9. In ST8, it is determined whether or not the current electrode position has reached the final command value. If the current electrode position has reached the final command value, the processing ends in ST19. If not, the process proceeds to ST9. ST
In step 9, it is checked whether the timer started in ST5 has reached a predetermined jump down time Jd. If the timer has not exceeded the predetermined jump down time Jd, the process returns to ST6. If the timer has exceeded the predetermined jump down time Jd, ST10,
The process proceeds to ST11, and the same processing as that of the related art is continuously performed. That is, in the present embodiment, when the electrode position reaches the final command value in a section other than the non-determination section during the processing period, it is determined that the processing has been completed.

As described above, after the jump operation is switched to the processing, the processing machine body is deformed so as to move away from the workpiece with the electrodes so that the main body of the processing machine slides due to the viscosity of the processing liquid and the pressure of the bubbles. Then, when the electric discharge continues, electric discharge dust is gradually accumulated in the machining gap, and the machining gap distance is gradually widened by the action of the gap control system. In the finishing processing, the processing gap distance of about 5 to 15 μm increases during the processing period, the processing reaction force due to the viscosity of the processing liquid and the pressure of the bubbles is greatly reduced, and the deformation of the processing machine body is reduced. Therefore, if a certain section in the processing period as described above is set as a non-determination section, and processing is terminated when the electrode position reaches a final command value of a desired shape in other than that section, the processing machine body becomes Processing end can be determined without deformation
It is possible to suppress a reduction in processing shape error and an increase in processing time.

By the way, in the electric discharge machining apparatus in the above embodiment, one non-determination section of ST20 shown in FIG. 1 may be defined during the machining period, or a plurality of non-determination sections may be defined during the machining period.

As described above, the electric discharge machine according to the present embodiment supplies the machining fluid 3 to the gap between the electrode 1 and the workpiece 2,
In the electric discharge machining of the workpiece 2 by supplying a machining pulse and applying a machining pulse to both the electrode 1 and the workpiece 2 and a periodic relative motion, the jump operation returns to the next jump operation. When the coordinate value of the electrode 1 or the workpiece 2 reaches a predetermined command value in a part other than a specified section within a jump down time Jd as a processing period until the start of the processing, it is determined that the processing is completed. .

In other words, it is possible to reliably determine the end of machining when it is not a non-judgment section within the jump-down time Jd as a machining period in which the deformation of the machine body does not occur, thereby reducing machining shape errors. Additional machining can be reduced, and the increase in machining time can be suppressed.

Embodiment 2 FIG. In the electric discharge machining apparatus according to the first embodiment of the present invention, as the area of the electrode 1 increases, the amount of deformation of the machine body so as to trace increases, and the time required for the deformation to return after the occurrence of electric discharge. Is also longer. If the time required for the deformation to return becomes longer and the jump-down time Jd is shorter, the jump-down time Jd ends before the deformation of the processing machine body returns, and the jump operation starts. In this case, the effects of reducing the error in the machined shape and suppressing the increase in the descent time cannot be sufficiently obtained. Therefore, when the processing area is large,
By increasing the minimum value of the jump down time Jd, it is necessary to secure a time for the deformation of the processing machine body to return.

Therefore, the electric discharge machine according to the second embodiment of the present invention has a configuration as shown in FIG. Note that components having the same configuration or corresponding portions as those of the above-described conventional device are denoted by the same reference numerals and symbols. In the figure, 1 is an electrode, 2 is a workpiece, 3 is a working fluid, 4 is a processing tank, 5 is an electrode rotating device that rotates the electrode 1 around the Z axis,
6 is a Y-axis table, 7 is a Y-axis drive for driving the Y-axis table 6 in the Y-axis direction, 8 is an X-axis table, 9 is an X-axis drive for driving the X-axis table 8 in the X-axis direction, and 10 is Z that drives the electrode rotating device 5 on which the electrode 1 is mounted in the Z-axis direction
An axis driving device, 11 is a processing power supply for supplying a processing pulse between the poles formed by the electrode 1 and the workpiece 2, 12 is a processing state detection device for detecting a processing state during processing, and 13 is a processing gap. A processing liquid supply device for supplying the liquid 3, an NC control device 14, an area information input device 23 for providing area information of the electrode 1 to the NC control device 14, and a jump operation condition 24 based on the provided area information. It is a jump condition setting device to be set.

FIG. 3 is a flowchart for explaining the operation of the electric discharge machine according to the second embodiment of the present invention.
In the figure, individual processing steps ST1 to ST11, ST19
The processing block BL2 is the same as the conventional one shown in FIG. ST100 is a processing step of acquiring information about the area, ST20 is a processing step of setting a section in which the processing end is not determined within the processing period, and ST21 is a step of determining whether the processing time belongs to a section in which the processing end is not determined within the processing period. This is a processing step for determining.

This embodiment is obtained by adding a processing step ST100 to the operation of the electric discharge machining apparatus of the first embodiment, and is characterized by an operation at the time of machining as compared with the conventional electric discharge machining apparatus. In the following, description will be made only during processing. First, in ST100, information on an area to be processed is obtained. This may be a method in which the worker inputs area information or a result recognized there in the case of an electric discharge machine capable of automatically recognizing the area. Next, in consideration of the information obtained in ST100, processing pulse conditions, jump operation conditions, control modes, and the like input by the operator in ST1 are initialized. As described above, the control mode is “processing”. In ST20, a non-determination section in which the completion of processing is not determined within the processing period is set. In ST2, input of a processing start is waited, and when the processing start is recognized, the process proceeds to ST3. In ST3,
Check the control mode. Since the control mode is "processing", the process proceeds to ST4. In ST4, the machining power supply is O
N, and supply of a processing pulse between the electrode and the workpiece is started. At the same time, in ST5, a timer is started to measure a predetermined jump down time. ST
6, ST7 is a part for realizing the function of the gap control described above, detects the gap voltage, compares the command value with the detected value to determine a deviation, and generates a machining locus command according to the deviation. An electrode movement command based on the output is output to the electrode driving device. Next, ST2
In step 1, it is determined whether or not the processing time belongs to the non-determination section set in ST20. if,
If the processing time is not in the non-determination section, the process proceeds to ST8.
If the processing time is in the non-determination section, the process proceeds to ST9. In ST8, it is determined whether or not the current electrode position has reached the final command value. If the current electrode position has reached the final command value, the processing ends in ST19. If not, the process proceeds to ST9. ST
In step 9, it is checked whether the timer started in ST5 has reached a predetermined jump down time Jd. If the timer has not exceeded the predetermined jump down time Jd, the process returns to ST6. If the timer has exceeded the predetermined jump down time Jd, ST10,
The process proceeds to ST11, and the same processing as that of the related art is continuously performed. That is, in the present embodiment, the processing period is set based on the information on the area of the electrode 1, and when the electrode position reaches the final command value other than the non-determination section during the processing period, it is determined that the processing is completed.

As described above, after the jump operation is switched to the processing, the processing machine is deformed so as to move away from the workpiece with the electrodes so that the main body of the processing machine traces due to the viscosity of the processing liquid and the pressure of the bubbles. Then, when the electric discharge continues, electric discharge dust is gradually accumulated in the machining gap, and the machining gap distance is gradually widened by the action of the gap control system. In the finishing processing, the processing gap distance of about 5 to 15 μm increases during the processing period, the processing reaction force due to the viscosity of the processing liquid and the pressure of the bubbles is greatly reduced, and the deformation of the processing machine body is reduced. Therefore, if a certain section in the processing period as described above is set as a non-determination section, and processing is terminated when the electrode position reaches a final command value of a desired shape in other than that section, the processing machine body becomes Processing end can be determined without deformation
The processing shape error can be reduced and the processing time can be minimized.

By the way, in the electric discharge machining apparatus of the above embodiment, one non-determination section of ST20 shown in FIG. 3 may be defined during the machining period, or a plurality of sections may be defined during the machining period.

As described above, the electric discharge machining apparatus of the present embodiment sets the minimum value of the jump down time Jd as the machining period based on at least one condition among the area, shape, material, and thickness of the electrode 1. When the coordinate value of the electrode 1 or the workpiece 2 reaches a predetermined command value in a section other than a specified section within the processing period, the processing is determined to be completed.

That is, since the minimum value of the jump-down time Jd as the processing period is set in consideration of the area, shape, material, and thickness of the electrode 1, it is designated corresponding to the period during which the processing machine body is deformed. The length of the jump-down time Jd is appropriately set so that the coordinate value of the electrode 1 or the workpiece 2 reaches a predetermined command value in a section other than the section where the jump has occurred. This allows
With the minimum required jump-down time Jd, the end of processing can be reliably determined when the processing machine body is not deformed, reducing processing error and reducing additional processing time. Can be minimized.

Embodiment 3 FIG. Hereinafter, a third embodiment of the present invention will be described. FIG. 4 is a flowchart for explaining the operation of the electric discharge machine according to the third embodiment. In the figure, individual processing steps ST1 to ST11, ST19 and processing block BL2
Is the same as that shown in the first embodiment. The configuration of the electric discharge machine according to the present embodiment is the same as that of the conventional apparatus shown in FIG. 10, and a description thereof will be omitted.

This embodiment is characterized by an operation at the time of machining, in particular, as compared with the conventional electric discharge machining apparatus. First, in ST1, processing pulse conditions, jump operation conditions, control modes, and the like input by an operator are initialized. As described above, the control mode is “processing”. In ST2, input of a processing start is waited, and when the processing start is recognized, the process proceeds to ST3. In ST3, the control mode is checked. Since the control mode is "processing", the process proceeds to ST4. ST
In 4, the processing power is turned on, and the supply of the processing pulse between the electrode and the workpiece is started. At the same time, ST5
In, a timer is started to measure a predetermined jump down time. ST6 and ST7 are parts that realize the function of the gap control described above, and detect the gap voltage,
A deviation is obtained by comparing the command value with the detected value, and an electrode movement command based on the machining trajectory command is output to the electrode driving device in accordance with the deviation. Next, in ST9, it is checked whether or not the timer started in ST5 has reached a predetermined jump down time Jd. If the timer has not exceeded the predetermined jump down time Jd, the process returns to ST6. If the timer has exceeded the predetermined jump down time Jd, the process proceeds to ST8. In ST8, it is determined whether or not the current electrode position has reached the final command value, that is, whether or not to finish machining. If the current electrode position has reached the final command value, the processing ends in ST19. If not reached, ST10, ST1
The process proceeds to 1 and the same processing as in the related art is continuously performed. That is, in the present embodiment, when the electrode position reaches the final command value at the last point in the processing period, it is determined that the processing is completed.

As described above, after switching from the jumping operation to the processing, the processing machine body is deformed so as to move away from the workpiece with the electrodes so that the main body of the processing machine traces due to the viscosity of the processing liquid and the pressure of the bubbles. Then, when the electric discharge continues, electric discharge dust is gradually accumulated in the machining gap, and the machining gap distance is gradually widened by the action of the gap control system. In the finishing processing, the processing gap distance of about 5 to 15 μm increases during the processing period, and at the end of the processing period, the processing reaction force due to the viscosity of the processing liquid and the pressure of the bubbles is greatly reduced, and the deformation of the processing machine body is small. Become. Therefore, as described above, if the machining is terminated at the end of the machining period when the electrode position reaches the final command value of the desired shape, it is possible to determine the machining end in a state where the machining machine body is not deformed. Therefore, it is possible to reduce the processing shape error and increase the processing time.

As described above, the electric discharge machine according to the present embodiment supplies the machining fluid 3 to the gap between the electrode 1 and the workpiece 2,
In the electric discharge machining of the workpiece 2 by supplying a machining pulse and applying a machining pulse to both the electrode 1 and the workpiece 2 and a periodic relative motion, the jump operation returns to the next jump operation. When the coordinate value of the electrode 1 or the workpiece 2 reaches a predetermined command value at the last point in the jump-down time Jd as a machining period until the start of the machining, the machining is determined to be completed.

That is, it is possible to reliably determine the end of machining at the last point in the jump-down time Jd as a machining period in which the deformation of the machine body does not occur, to reduce machining shape errors, and to perform additional machining. And increase in machining time can be suppressed.

Embodiment 4 FIG. In the electric discharge machining apparatus according to the third embodiment of the present invention, as described above, as the area of the electrode 1 increases, the amount of deformation of the machining machine main body increases, and the deformation occurs after the electric discharge occurs. The time it takes to return is longer. If the time required for the deformation to return becomes longer, the jump-down time J
When d is short, the jump-down time Jd ends before the deformation of the processing machine body returns, and the operation shifts to the jump operation. In this case, the effects of reducing the error in the machined shape and suppressing the increase in the descent time cannot be sufficiently obtained. Therefore, when the processing area is large, it is necessary to secure the time for the deformation of the processing machine body to return by increasing the minimum value of the jump-down time Jd.

Therefore, the electric discharge machine according to the fourth embodiment of the present invention has a configuration as shown in FIG. FIG. 5 is a flowchart for explaining the operation of the electric discharge machine according to the fourth embodiment of the present invention. In the figure, individual processing steps ST1 to ST11, ST19 and processing block BL2
Is the same as that shown in the first embodiment.

This embodiment is obtained by adding a processing step ST100 to the operation of the electric discharge machining apparatus according to the third embodiment, and is characterized by an operation at the time of machining, in particular, as compared with the conventional electric discharge machining apparatus. Therefore, the description will be made below only during processing. First, in ST100, information on an area to be processed is obtained. This may be a method in which the worker inputs area information or a result recognized there in the case of an electric discharge machine capable of automatically recognizing the area. Next, in consideration of the information obtained in ST100, processing pulse conditions, jump operation conditions, control modes, and the like input by the operator in ST1 are initialized. As described above, the control mode is “processing”. In ST2, input of a processing start is waited, and when the processing start is recognized, the process proceeds to ST3. In ST3, the control mode is checked. Since the control mode is "processing", the process proceeds to ST4. In ST4, the processing power is turned on, and the supply of the processing pulse between the electrode and the workpiece is started. At the same time, in ST5, a timer is started to measure a predetermined jump down time. ST6 and ST7 are parts that realize the function of the gap control described above, detect the gap voltage, compare the command value with the detected value, and calculate the deviation,
An electrode movement command based on the processing locus command is output to the electrode driving device according to the deviation. Next, in ST9, ST
It is checked whether the timer started in step 5 has reached a predetermined jump down time Jd. If the timer has not exceeded the predetermined jump down time Jd,
Return to ST6. If the timer has exceeded the predetermined jump down time Jd, the process proceeds to ST8. In ST8, whether the current electrode position has reached the final command value,
That is, it is determined whether or not to end the processing. If the current electrode position has reached the final command value, ST1
The processing ends at 9. If not, ST
10, the process proceeds to ST11, and the same processing as the conventional one is continuously performed. That is, in the present embodiment, the processing period is set based on the information regarding the area of the electrode 1, and when the electrode position reaches the final command value at the end of the processing period, it is determined that the processing is completed.

As described above, after switching from the jump operation to the processing, the processing machine body is deformed so as to move away from the workpiece with the electrodes so that the processing machine main body traces due to the viscosity of the processing liquid or the pressure of bubbles. Then, when the electric discharge continues, electric discharge dust is gradually accumulated in the machining gap, and the machining gap distance is gradually widened by the action of the gap control system. In the finishing processing, the processing gap distance of about 5 to 15 μm increases during the processing period, and at the end of the processing period, the processing reaction force due to the viscosity of the processing liquid and the pressure of the bubbles is greatly reduced, and the deformation of the processing machine body is small. Become. Therefore, as described above, if the machining is terminated at the end of the machining period when the electrode position reaches the final command value of the desired shape, it is possible to determine the machining end in a state where the machining machine body is not deformed. Therefore, the processing shape error can be reduced and the processing time can be minimized.

As described above, the electric discharge machining apparatus of the present embodiment sets the minimum value of the jump down time Jd as the machining period based on at least one condition among the area, shape, material, and thickness of the electrode 1. When the coordinate value of the electrode 1 or the workpiece 2 reaches a predetermined command value at the last point in the jump-down time Jd, it is determined that the machining is completed.

That is, the minimum value of the jump-down time Jd as the processing period is set in consideration of the area, shape, material, and thickness of the electrode 1 and the last point in the jump-down time Jd is set. The length of the jump-down time Jd is appropriately set so that the coordinate value of the electrode 1 or the workpiece 2 reaches a predetermined command value except during a period in which is deformed. As a result, it is possible to reliably determine the end of processing when the deformation of the processing machine body has not occurred with the required minimum length of the jump-down time Jd, thereby reducing a processing shape error and reducing additional processing. Processing time can be minimized.

Embodiment 5 FIG. Hereinafter, a fifth embodiment of the present invention will be described. FIG. 6 is a flowchart for explaining the operation of the electric discharge machine according to the fifth embodiment. In the figure, individual processing steps ST1 to ST11, ST19 to ST21 and processing block BL2 are the same as those shown in the first embodiment.
ST22 is a processing step for clearing the short-circuit flag, ST23
ST24 is a processing step for determining whether or not a short circuit has occurred. ST24 is a processing step for setting a short circuit flag.
25 is a processing step for determining whether or not the short-circuit flag is set. Note that the configuration of the electric discharge machine of the present embodiment is the same as that of the conventional apparatus of FIG.
The description is omitted.

Since this embodiment is characterized by an operation at the time of machining, in particular, as compared with the conventional electric discharge machine, the following description will be limited to the machining. First, in ST1, processing pulse conditions, jump operation conditions, control modes, and the like input by an operator are initialized. As described above, the control mode is “processing”. In ST20, a non-determination section in which the completion of processing is not determined within the processing period is set. In ST2, input of a processing start is waited, and when the processing start is recognized, the process proceeds to ST3. In ST3,
A control mode check is performed. Since the control mode is "processing", the process proceeds to ST4. In ST4, the processing power is turned on, and the supply of the processing pulse between the electrode and the workpiece is started. In ST22, the short-circuit flag is cleared. At the same time, in ST5, a timer is started to measure a predetermined jump down time. ST
6, ST7 is a part that realizes the function of the gap control described above, detects the gap voltage, compares the command value with the detected value to determine a deviation, and outputs a machining locus command according to the deviation. An electrode movement command based on the output is output to the electrode driving device. In ST23, it is determined whether or not a short-circuit condition has occurred. If a short-circuit condition has occurred, a short-circuit flag is set in ST24, and the process proceeds to ST21. If a short circuit has not occurred, the process proceeds to ST21. The determination of the occurrence of a short circuit in ST23 can be made, for example, with reference to the voltage between contacts detected in ST6. Next, in ST21, it is determined whether or not the processing time belongs to the non-determination section set in ST20. If the processing time is not in the non-determination section, the process proceeds to ST8. If the processing time is in the non-determination section, the process proceeds to ST9. ST8
In, it is determined whether or not the current electrode position has reached the final command value. If not, ST
Go to 9. If the current electrode position has reached the final command value, it is further determined in ST25 whether or not the short-circuit flag has been set. If the short-circuit flag is set, the process proceeds to ST9. If the short-circuit flag has not been set, the processing is terminated in ST19. In ST9, it is checked whether or not the timer started in ST5 has reached a predetermined jump down time Jd. If the timer reaches the predetermined jump down time Jd
If not, return to ST6. If the timer has exceeded the predetermined jump down time Jd, ST1
0, the process proceeds to ST11, and the same processing as in the related art is continuously performed. That is, in the present embodiment, when the electrode position reaches the final command value in the non-determination section during the processing period and no short circuit occurs during the processing period, it is determined that the processing is completed.

As described above, after switching from the jump operation to the processing, the processing machine is deformed so as to move away from the workpiece with the electrodes so that the main body of the processing machine slides due to the viscosity of the processing liquid and the pressure of the bubbles. Then, when the electric discharge continues, electric discharge dust is gradually accumulated in the machining gap, and the machining gap distance is gradually widened by the action of the gap control system. In the finishing processing, the processing gap distance of about 5 to 15 μm increases during the processing period, the processing reaction force due to the viscosity of the processing liquid and the pressure of the bubbles is greatly reduced, and the deformation of the processing machine body is reduced. By the way, when a short-circuit condition occurs during the machining period, the electrode is pulled up at high speed so as to increase the machining gap distance in order to avoid the short-circuit condition by the gap control system, and when the machining condition recovers, the electrode is sent to the workpiece side. At this time, there is a possibility that the processing machine body is deformed so as to move away from the workpiece along with the electrodes so that the main body of the processing machine slides. Therefore, a certain section in the processing period as described above is defined as a non-determination section, and when the electrode position reaches the final command value of a desired shape in a section other than that section, no short circuit occurs during the processing period. If the machining is sometimes terminated, it is possible to determine the machining end in a state where the machining machine body is not deformed, and it is possible to reduce a machining shape error and suppress an increase in machining time.

As described above, in the electric discharge machining apparatus of this embodiment, the coordinate value of the electrode 1 or the workpiece 2 has reached the predetermined command value, and a short circuit has occurred during the machining period. When there is no processing, it is determined that the processing is completed.

That is, during the jump-down time Jd as a processing period during which the deformation of the processing machine body does not occur, the electrode 1
Alternatively, when the coordinate value of the workpiece 2 reaches a predetermined command value, a short circuit does not occur during this time, and the electrode 1 is not driven in the Z-axis direction, it is determined that the machining is finished. For this reason, when the deformation of the processing machine main body does not occur, it is possible to reliably determine the end of the processing, to reduce a processing shape error, to reduce additional processing, and to suppress an increase in processing time.

Embodiment 6 FIG. In the electric discharge machining apparatus according to the fifth embodiment of the present invention, as described above, as the area of the electrode 1 increases, the amount of deformation of the machining machine body in a tracing manner increases. The time it takes to return is longer. If the time required for the deformation to return becomes longer, the jump-down time J
When d is short, the jump-down time Jd ends before the deformation of the processing machine body returns, and the operation shifts to the jump operation. In this case, the effects of reducing the error in the machined shape and suppressing the increase in the descent time cannot be sufficiently obtained. Therefore, when the processing area is large, it is necessary to secure the time for the deformation of the processing machine body to return by increasing the minimum value of the jump-down time Jd.

Therefore, the electric discharge machine according to the sixth embodiment of the present invention has a configuration as shown in FIG. FIG. 7 is a flowchart for explaining the operation of the electric discharge machine according to the sixth embodiment of the present invention. In the figure, individual processing steps ST1 to ST11, ST19 to ST21 and processing block BL2 are the same as those shown in the first embodiment.
ST22 is a processing step for clearing the short-circuit flag, ST23
ST24 is a processing step for determining whether or not a short circuit has occurred. ST24 is a processing step for setting a short circuit flag.
25 is a processing step for determining whether or not the short-circuit flag is set.

This embodiment is obtained by adding a processing step ST100 to the operation of the electric discharge machining apparatus of the fifth embodiment, and is characterized by an operation at the time of machining, in particular, as compared with the conventional electric discharge machining apparatus. Therefore, the description will be made below only during processing. First, in ST100, information on an area to be processed is obtained. This may be a method in which the worker inputs area information or a result recognized there in the case of an electric discharge machine capable of automatically recognizing the area. Next, in consideration of the information obtained in ST100, processing pulse conditions, jump operation conditions, control modes, and the like input by the operator in ST1 are initialized. As described above, the control mode is “processing”. In ST20, a non-determination section in which the completion of processing is not determined within the processing period is set. In ST2, input of a processing start is waited, and when the processing start is recognized, the process proceeds to ST3. In ST3, the control mode is checked. Since the control mode is "processing", the process proceeds to ST4. In ST4, the processing power is turned on, and the supply of the processing pulse between the electrode and the workpiece is started. In ST22, the short-circuit flag is cleared. At the same time, in ST5, a timer is started to measure a predetermined jump down time. ST
6, ST7 is a part that realizes the function of the gap control described above, detects the gap voltage, compares the command value with the detected value to determine a deviation, and outputs a machining locus command according to the deviation. An electrode movement command based on the output is output to the electrode driving device. In ST23, it is determined whether or not a short-circuit condition has occurred. If a short-circuit condition has occurred, a short-circuit flag is set in ST24, and the process proceeds to ST21. If a short circuit has not occurred, the process proceeds to ST21. The determination of the occurrence of a short circuit in ST23 can be made, for example, with reference to the voltage between contacts detected in ST6. Next, in ST21, it is determined whether or not the processing time belongs to the non-determination section set in ST20. If the processing time is not in the non-determination section, the process proceeds to ST8. If the processing time is in the non-determination section, the process proceeds to ST9. ST8
In, it is determined whether or not the current electrode position has reached the final command value. If not, ST
Go to 9. If the current electrode position has reached the final command value, it is further determined in ST25 whether or not the short-circuit flag has been set. If the short-circuit flag is set, the process proceeds to ST9. If the short-circuit flag has not been set, the processing is terminated in ST19. In ST9, it is checked whether or not the timer started in ST5 has reached a predetermined jump down time Jd. If the timer reaches the predetermined jump down time Jd
If not, return to ST6. If the timer has exceeded the predetermined jump down time Jd, ST1
0, the process proceeds to ST11, and the same processing as in the related art is continuously performed. That is, in the present embodiment, the processing period is set based on the information on the area of the electrode 1, the electrode position reaches the final command value in a non-determination section during the processing period, and a short circuit occurs during the processing period. If not, it is determined that the processing has been completed.

As described above, after switching from the jump operation to the processing, the processing machine is deformed so as to move away from the workpiece with the electrodes so that the main body of the processing machine traces due to the viscosity of the processing liquid and the pressure of the bubbles. Then, when the electric discharge continues, electric discharge dust is gradually accumulated in the machining gap, and the machining gap distance is gradually widened by the action of the gap control system. In the finishing processing, the processing gap distance of about 5 to 15 μm increases during the processing period, the processing reaction force due to the viscosity of the processing liquid and the pressure of the bubbles is greatly reduced, and the deformation of the processing machine body is reduced. By the way, when a short-circuit condition occurs during the machining period, the electrode is pulled up at high speed so as to increase the machining gap distance in order to avoid the short-circuit condition by the gap control system, and when the machining condition recovers, the electrode is sent to the workpiece side. At this time, there is a possibility that the processing machine body is deformed so as to move away from the workpiece along with the electrodes so that the main body of the processing machine slides. Therefore, a certain section in the processing period as described above is defined as a non-determination section, and when the electrode position reaches the final command value of a desired shape in a section other than that section, no short circuit occurs during the processing period. If the processing is sometimes terminated, it is possible to determine the end of the processing in a state where the processing machine main body is not deformed, and it is possible to reduce a processing shape error and minimize a processing time.

In the electric discharge machining apparatus according to the above embodiment, one non-determination section of ST20 shown in FIG. 7 may be defined during the machining period, or a plurality of sections may be defined during the machining period.

As described above, in the electric discharge machining apparatus of the present embodiment, the coordinate value of the electrode 1 or the workpiece 2 has reached the predetermined command value, and a short circuit has occurred during the machining period. When there is no processing, it is determined that the processing is completed.

That is, the coordinate value of the electrode 1 or the workpiece 2 becomes a predetermined command value with the minimum value of the jump-down time Jd as a processing period set in consideration of the area, shape, material, and thickness of the electrode 1. And a short circuit does not occur during this time.
When there is no drive in the Z-axis direction, it is determined that the machining is finished. For this reason, when the deformation of the processing machine main body does not occur, it is possible to reliably determine the end of the processing, to reduce the processing shape error, to reduce the additional processing, and to minimize the processing time.

Embodiment 7 FIG. Hereinafter, a seventh embodiment of the present invention will be described. FIG. 8 is a flowchart for explaining the operation of the electric discharge machine according to the seventh embodiment. In the figure, individual processing steps ST1 to ST11, ST19 and processing block BL2
Is the same as that shown in the first embodiment. ST26 is a processing step for clearing the arrival flag and the invalid flag, ST27 is a processing step for setting the arrival flag,
28 is a processing step for determining whether the arrival flag is set, ST29 is a processing step for setting the invalid flag, ST30 is a processing step for determining whether the invalid flag is set, and ST31 is a processing step for determining whether the arrival flag is set. This is a processing step for determining whether or not there is any data. Note that the configuration of the electric discharge machining apparatus of the present embodiment is the same as that of the conventional apparatus of FIG. 10, and a description thereof will be omitted.

This embodiment is particularly characterized in the operation at the time of machining, as compared with the conventional electric discharge machining apparatus. Therefore, the following description will be limited to the machining. First, in ST1, processing pulse conditions, jump operation conditions, control modes, and the like input by an operator are initialized. As described above, the control mode is “processing”. In ST2, input of a processing start is waited, and when the processing start is recognized, the process proceeds to ST3. In ST3, the control mode is checked. Since the control mode is "processing", the process proceeds to ST4. ST
In 4, the processing power is turned on, and the supply of the processing pulse between the electrode and the workpiece is started. In ST26,
Clear the arrival flag and invalid flag. At the same time, in ST5, a timer is started to measure a predetermined jump down time. ST6 and ST7 are parts that realize the function of the gap control described above, detect the gap voltage, compare the command value with the detected value, and calculate the deviation,
An electrode movement command based on the processing locus command is output to the electrode driving device according to the deviation. Next, in ST8, it is determined whether or not the current electrode position has reached the final command value. If the current electrode position has reached the final command value, an arrival flag is set in ST27, and the process proceeds to ST9. If the electrode position has not reached the final command value, the process proceeds to ST28. In ST28, it is determined whether or not the arrival flag is set. If the arrival flag has not been set, the process proceeds to ST9. If the arrival flag is set, ST2
In step 9, an invalid flag is set, and the process proceeds to ST9. In ST9, it is checked whether or not the timer started in ST5 has reached a predetermined jump down time Jd.
If the timer has not exceeded the predetermined jump down time Jd, the process returns to ST6. If the timer has exceeded the predetermined jump down time Jd, the process proceeds to ST30. In ST30, it is determined whether or not the invalid flag is set. If the invalid flag is set, the process proceeds to ST10 and ST11. If the invalid flag has not been set, the process proceeds to ST31. In ST31, it is determined whether or not the arrival flag is set. If the arrival flag has not been set, the process proceeds to ST10 and ST11. If the arrival flag is set, the processing ends in ST19. That is, in the present embodiment, after the electrode position reaches the final command value within the processing period, when the electrode position remains at the final command value until the last point in the processing period, it is determined that the processing is completed.

As described above, after switching from the jump operation to the processing, the processing machine body is deformed so as to move away from the workpiece with the electrodes so that the main body of the processing machine traces due to the viscosity of the processing liquid and the pressure of the bubbles. Then, when the electric discharge continues, electric discharge dust is gradually accumulated in the machining gap, and the machining gap distance is gradually widened by the action of the gap control system. At this time, the main body of the processing machine repeats deformation such that it moves away from the workpiece with the electrode as if to trace, and deformation that approaches the workpiece with the electrode as it looks down. Decreases. In the finishing processing, the processing gap distance of about 5 to 15 μm increases during the processing period, the processing reaction force due to the viscosity of the processing liquid and the pressure of the bubbles is greatly reduced, and the deformation of the processing machine body is small at the end of the processing period. Become. Therefore, if the electrode position reaches the final command value during the processing period, and the processing is terminated when the electrode position remains at the final command value until the end of the processing period, the processing machine body is deformed. Processing end can be determined in a state where the processing is not performed, and a reduction in processing shape error and an increase in processing time can be suppressed.

As described above, the electric discharge machine according to the present embodiment supplies the machining fluid 3 to the gap between the electrode 1 and the workpiece 2,
In the electric discharge machining of the workpiece 2 by supplying a machining pulse and applying a machining pulse to both the electrode 1 and the workpiece 2 and a periodic relative motion, the jump operation returns to the next jump operation. After the coordinate value of the electrode 1 or the workpiece 2 once reaches a predetermined command value within a jump-down time Jd as a processing period until the start of the operation, the coordinate value is maintained until the last point in the processing period. When the value remains at the value, the processing is determined to be completed.

That is, during the jump-down time Jd as a processing period in which the deformation of the processing machine body does not occur, the electrode 1
Alternatively, after the coordinate value of the workpiece 2 once reaches the predetermined command value, when the command value remains at the command value until the last time point, it is possible to reliably determine the end of the processing, reduce the processing shape error,
Additional machining can be reduced, and the increase in machining time can be suppressed.

Embodiment 8 FIG. In the electric discharge machine according to the seventh embodiment of the present invention, as described above, as the area of the electrode 1 increases, the amount of deformation of the machine main body so as to trace increases, and the deformation occurs after the discharge occurs. The time it takes to return is longer. If the time required for the deformation to return becomes longer, the jump-down time J
When d is short, the jump-down time Jd ends before the deformation of the processing machine body returns, and the operation shifts to the jump operation. In this case, the effects of reducing the error in the machined shape and suppressing the increase in the descent time cannot be sufficiently obtained. Therefore, when the processing area is large, it is necessary to secure the time for the deformation of the processing machine body to return by increasing the minimum value of the jump-down time Jd.

Therefore, the electric discharge machine according to the eighth embodiment of the present invention has a configuration as shown in FIG. FIG. 9 shows the eighth
5 is a flowchart for explaining the operation of the electric discharge machine according to the embodiment. In the figure, individual processing steps
ST1 to ST11, ST19 and the processing block BL2 are the same as those shown in the first embodiment. ST26 is a processing step for clearing the arrival flag and the invalid flag, ST27
Is a processing step of setting an arrival flag, ST28 is a processing step of determining whether or not the arrival flag is set, ST29 is a processing step of setting an invalid flag,
ST30 is a processing step for determining whether or not the invalid flag is set, and ST31 is a processing step for determining whether or not the arrival flag is set.

This embodiment is obtained by adding a processing step ST100 to the operation of the electric discharge machine according to the seventh embodiment, and is characterized by an operation at the time of machining, in particular, as compared with the electric discharge machine of the conventional example. Therefore, the description will be made below only during processing. First, in ST100, information on an area to be processed is obtained. This may be a method in which the worker inputs area information or a result recognized there in the case of an electric discharge machine capable of automatically recognizing the area. Next, in consideration of the information obtained in ST100, processing pulse conditions, jump operation conditions, control modes, and the like input by the operator in ST1 are initialized. As described above, the control mode is “processing”. In ST2, input of a processing start is waited, and when the processing start is recognized, the process proceeds to ST3. In ST3, the control mode is checked. Since the control mode is "processing", the process proceeds to ST4. In ST4, the processing power is turned on, and the supply of the processing pulse between the electrode and the workpiece is started. In ST26, the arrival flag and the invalid flag are cleared. At the same time, in ST5, a timer is started to measure a predetermined jump down time. ST6, ST7
Is a part that realizes the function of the gap control described above, detects the gap voltage, determines a deviation by comparing the command value and the detected value, and determines an electrode based on the machining locus command according to the deviation. The movement command is output to the electrode driving device. Next, in ST8, it is determined whether or not the current electrode position has reached the final command value. If the current electrode position has reached the final command value, an arrival flag is set in ST27, and the process proceeds to ST9. If the electrode position has not reached the final command value, the process proceeds to ST28. In ST28, it is determined whether or not the arrival flag is set. If the arrival flag is not set, ST
The process proceeds to 9. If the arrival flag is set, an invalid flag is set in ST29, and the process proceeds to ST9. In ST9, it is checked whether or not the timer started in ST5 has reached a predetermined jump down time Jd. If the timer has not exceeded the predetermined jump down time Jd, the process returns to ST6. If the timer has exceeded the predetermined jump-down time Jd,
Proceed to ST30. In ST30, it is determined whether or not the invalid flag is set. If the invalid flag is set, the process proceeds to ST10 and ST11. if,
If the invalid flag has not been set, the process proceeds to ST31. In ST31, it is determined whether or not the arrival flag is set. If the arrival flag has not been set, the process proceeds to ST10 and ST11. If the arrival flag is set, the processing ends in ST19. That is, in the present embodiment, the processing period is set based on the information on the area of the electrode 1, and after the electrode position reaches the final command value during the processing period, the electrode position is changed until the last point in the processing period. It is determined that machining has ended when the value remains at the final command value.

As described above, after switching from the jump operation to the processing, the processing machine is deformed so as to move away from the workpiece with the electrodes so that the main body of the processing machine moves by the viscosity of the processing liquid and the pressure of the bubbles. Then, when the electric discharge continues, electric discharge dust is gradually accumulated in the machining gap, and the machining gap distance is gradually widened by the action of the gap control system. At this time, the main body of the processing machine repeats deformation such that it moves away from the workpiece with the electrode as if to trace, and deformation that approaches the workpiece with the electrode as it looks down. Decreases. In the finishing processing, the processing gap distance of about 5 to 15 μm increases during the processing period, the processing reaction force due to the viscosity of the processing liquid and the pressure of the bubbles is greatly reduced, and the deformation of the processing machine main body at the end of the processing period. Become smaller. Therefore, if the electrode position reaches the final command value during the machining period and the machining is terminated when the electrode position remains at the final command value until the last point in the machining period, the processing machine body is deformed. Processing completion can be determined in a state where the processing has not been performed, and a processing shape error can be reduced and a processing time can be minimized.

As described above, the electric discharge machining apparatus of the present embodiment sets the minimum value of the jump down time Jd as the machining period based on at least one condition among the area, shape, material, and thickness of the electrode 1. After the coordinate value of the electrode 1 or the workpiece 2 once reaches the predetermined command value within the processing period, when the coordinate value remains at the command value until the last point in the processing period, the processing is determined to be completed. Things.

That is, the minimum value of the jump-down time Jd as the machining period is such that the coordinate value of the electrode 1 or the workpiece 2 once reaches a predetermined command value in consideration of the area, shape, material, and thickness of the electrode 1. Then, by setting so as to stay at the command value until the last point, jump down so that the coordinate value of the electrode 1 or the workpiece 2 reaches the predetermined command value except during the period when the processing machine body is deformed. The length of time Jd is set appropriately. As a result, it is possible to reliably determine the end of processing when the deformation of the processing machine body has not occurred with the required minimum length of the jump-down time Jd, thereby reducing a processing shape error and reducing additional processing. Processing time can be minimized.

[0066]

As described above, according to the electric discharge machining apparatus of the first aspect, the machining fluid is supplied to the gap between the electrode and the workpiece.
In an electric discharge machine that discharges a workpiece by supplying a machining pulse while giving a jump operation that is a periodic relative movement to both the electrode and the workpiece, the next jump operation is performed after returning from the jump operation. Determining the end of machining when the coordinate value of the electrode or the workpiece reaches a predetermined command value in a section other than a specified section within the machining period up to the start, that is, when no deformation of the machine body has occurred. Therefore, there is an effect that the machining shape error is reduced, additional machining is reduced, and increase in machining time is suppressed. In addition, the minimum value of the processing period is set based on at least one condition among the area, shape, material, and thickness of the electrode, and the coordinate value of the electrode or the workpiece is set in a part other than a specified section in the processing period. When the predetermined command value is reached, that is, when the processing machine body is not deformed, the processing end is determined, so that the processing shape error is reduced, the additional processing is reduced, and the processing time is minimized. effective. In addition, electrodes or workpieces
Coordinate value has reached the specified command value, and
When a short circuit has not occurred during the construction period,
Determines the end of machining when the body is not deformed.
Therefore, machining shape errors are reduced,
This has the effect of suppressing an increase in the construction time.

According to the second aspect of the present invention, the machining fluid is supplied to the gap between the electrode and the workpiece to give a jump operation which is a periodic relative motion to both the electrode and the workpiece. In an electric discharge machine that supplies a machining pulse and discharges a workpiece, the minimum value of the machining period from returning from the jump operation to starting the next jump operation is determined by the area, shape, material, and thickness of the electrode. It is set based on one or more conditions, and processing is performed when the coordinate value of the electrode or the workpiece reaches a predetermined command value at the last point in the processing period, that is, when the deformation of the processing machine body has not occurred. Is performed, so that there is an effect that the machining shape error is reduced, additional machining is reduced, and an increase in machining time is suppressed. In addition,
The minimum value of the construction period is defined as the electrode area, shape, material, and thickness.
Set based on one or more conditions, at the end of the processing period
At the point, the coordinate value of the electrode or workpiece reaches the specified command value
In other words, the deformation of the machine body has not occurred
Sometimes the end of machining is determined, reducing machining shape errors
To reduce machining time by minimizing additional machining
Has the effect. In addition, the coordinates of the electrode or workpiece
Command value has been reached and is short during the machining period.
When no tangling occurs, that is, when the deformation of the processing machine
When it does not occur, the end of processing is determined.
Reduces shape errors, reduces additional machining and increases machining time
There is a cormorant effect not and suppressed.

According to the third aspect of the present invention, the machining fluid is supplied to the gap between the electrode and the workpiece to give a jump operation, which is a periodic relative motion, to both the electrode and the workpiece. In an electric discharge machine that supplies a machining pulse and discharges a workpiece, the minimum value of the machining period from returning from the jump operation to starting the next jump operation is determined by the area, shape, material, and thickness of the electrode. Set based on one or more conditions, after the coordinate value of the electrode or workpiece once reaches a predetermined command value within the processing period, when the coordinate value remains at the command value until the last point in the processing period, That is, since the end of processing is determined when the deformation of the processing machine body is not occurring, there is an effect that a processing shape error is reduced, an additional processing is reduced, and an increase in processing time is suppressed.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an operation of an electric discharge machine according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating an electric discharge machine according to a second embodiment of the present invention.

FIG. 3 is a flowchart illustrating an operation of the electric discharge machine according to the second embodiment of the present invention.

FIG. 4 is a flowchart illustrating an operation of an electric discharge machine according to a third embodiment of the present invention.

FIG. 5 is a flowchart illustrating an operation of an electric discharge machine according to a fourth embodiment of the present invention.

FIG. 6 is a flowchart illustrating an operation of an electric discharge machine according to a fifth embodiment of the present invention.

FIG. 7 is a flowchart illustrating an operation of an electric discharge machine according to a sixth embodiment of the present invention.

FIG. 8 is a flowchart illustrating an operation of an electric discharge machine according to a seventh embodiment of the present invention.

FIG. 9 is a flowchart illustrating an operation of the electric discharge machine according to the eighth embodiment of the present invention.

FIG. 10 is a configuration diagram showing a conventional electric discharge machine.

FIG. 11 is a block diagram showing the operation of a conventional electric discharge machine.

FIG. 12 is an explanatory diagram showing mechanical characteristics in actual operation of a conventional electric discharge machine.

FIG. 13 is an explanatory diagram showing electrode moving speed control during a jump operation in a conventional electric discharge machine.

FIG. 14 is an explanatory diagram schematically showing spindle displacement during a jump operation and during machining in a conventional electric discharge machine.

FIG. 15 is a flowchart showing a processing procedure representing an operation of a conventional electric discharge machine.

FIG. 16 is an explanatory diagram showing mechanical characteristics of a conventional electric discharge machine.

[Description of Signs] 1 electrode, 2 workpiece, 3 working fluid, ST20
Processing step of setting a non-determination section, ST21 processing step of determining whether or not the section belongs to a non-determination section, ST22
ST23, a processing step of clearing a short-circuit flag, a processing step of determining whether a short-circuit state has occurred, ST2.
4. Processing step for setting short-circuit flag, ST25 Processing step for determining whether short-circuit flag is set, ST26 Processing step for clearing arrival flag and invalid flag, ST27 Processing step for setting arrival flag, ST28 Processing flag for setting ST31, a processing step of setting an invalid flag, ST30, a processing step of determining whether an invalid flag is set, ST31.
A processing step of determining whether or not the arrival flag is set, and a processing step of inputting area information in ST100.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hidetaka Miyake 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Corporation (72) Inventor Masahiro Yamamoto 2-6-1 Otemachi, Chiyoda-ku, Tokyo Mitsubishi (56) References JP-A-5-116031 (JP, A) JP-A-2-100830 (JP, A) JP-A-3-270825 (JP, A) JP-A-5-50330 ( JP, A) JP-B-56-13566 (JP, B2) JP-B-58-47292 (JP, B2) JP-B 4-31806 (JP, B2) (58) Fields surveyed (Int. Cl. ⁷ , (DB name) B23H 1/02

Claims (3)

(57) [Claims] 1. A machining liquid is supplied to a gap between an electrode and a workpiece to give a jumping operation which is a periodic relative motion to both the electrode and the workpiece and supply a machining pulse to the workpiece. In an electric discharge machine for electric discharge machining of a workpiece, the minimum value of the machining period from the return from the jump operation to the start of the next jump operation is set to one or more conditions among the area, shape, material, and thickness of the electrode. Set based on, when the coordinate value of the electrode or the workpiece reaches a predetermined command value other than a specified section in the processing period , and
An electric discharge machine characterized by determining that machining has ended when no short circuit has occurred during the machining period . 2. A processing liquid is supplied to a gap between an electrode and a workpiece, a jumping operation, which is a periodic relative motion, is applied to both the electrode and the workpiece, and a processing pulse is supplied. In an electric discharge machine for electric discharge machining of a workpiece, the minimum value of the machining period from the return from a jump operation to the start of the next jump operation is determined by the area, shape, material, and thickness of the electrode.
Only when the coordinate value of the electrode or the workpiece reaches a predetermined command value at the last point in the processing period, and during the processing period.
An electric discharge machine characterized by determining that machining has been completed when no short circuit has occurred . 3. A processing liquid is supplied to a gap between an electrode and a workpiece, a jumping operation, which is a periodic relative motion, is applied to both the electrode and the workpiece, and a processing pulse is supplied. In an electric discharge machine for electric discharge machining of a workpiece, the minimum value of the machining period from the return from a jump operation to the start of the next jump operation is determined by the area, shape, material, and thickness of the electrode.
Only after the coordinate value of the electrode or the workpiece once reaches a predetermined command value within the processing period, the coordinate value is set based on at least one condition in the processing period. An electric discharge machine characterized by determining that machining is completed when the command value remains at the command value up to a point in time.