JP2001054821A - Electric discharge machine and jump control method for electric discharge machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a lowering of machining accuracy in electric discharge machining due to the damage of a workpiece and a machining electrode and the generation of vibration in an electric discharge machine. SOLUTION: The position on the swinging path of a machining electrode 15 is changed before and after jumping action to prevent the damage of a workpiece 13 or the exhaustion of the machining electrode 15 caused by concentrated electric discharge. Different jumping speeds are set between the time of including horizontal components and the time of including only vertical components in the direction of jumping action of the machining electrode 15. The speed is thereby changed at the start-stop points, direction changing point and turn-around point of the machining electrode 15, in the horizontal direction in which vibration is easily generated by impact force generated in an electric discharge machine 11 and the vertical direction in which vibration is hardly generated, thus suppressing the generation of vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric discharge machine for controlling a jump operation of a machining electrode in order to improve machining accuracy in electric discharge machining accompanied with rocking machining, and a jump control method for the electric discharge machine.

[0002]

2. Description of the Related Art In electric discharge machining, generally, a work (workpiece) is placed in a machining bath and immersed in a working fluid such as insulating oil filled in the machining bath. A processing electrode is disposed above a work (workpiece) at a predetermined interval so as to face each other, and electric energy such as a pulse voltage is applied between the processing electrode and the work, that is, between the electrodes, and discharge is generated between the electrodes. At the same time, the machining electrode and the workpiece are relatively moved by the automatic feed function to perform desired machining on the workpiece. It has been found that, during this discharge, not only the workpiece but also the machining electrode is damaged, and the damage increases as the discharge energy increases and as the discharge continues in the same place. At the time of machining, if the machining electrode and the workpiece are too far apart, no electric discharge will occur, and if the machining electrode and the workpiece are too close together, short-circuiting will not be possible. Therefore, the relative movement between the machining electrode and the work is controlled such that the voltage applied between the electrodes is detected and the detected inter-electrode voltage is constant, that is, the machining gap is constant. Done. Here, "relatively move the processing electrode" in the specification of the present application means to move the processing electrode with respect to the workpiece by moving both or one of the workpiece and the processing electrode, and the workpiece is moved to the processing electrode. This also includes moving.

[0003] Regarding the relative movement between the workpiece and the processing electrode, the processing feed is such that the processing electrode is gradually lowered while repeating a minute movement mainly in the vertical direction or the vertical direction (Z-axis direction) as the processing proceeds. At the same time, it is general that a swing operation mainly performed in a processing side direction (a direction perpendicular to the Z-axis direction) and a jump operation in which the processing electrode is lifted up and returned to the work are performed.

The swing is to eccentrically move the machining electrode on a small closed path with respect to the workpiece, thereby performing enlargement machining in the machining side direction. For example, it is performed by performing a relative eccentric movement so as to draw a locus such as a circular shape. In the swing processing performed in this manner, generally, the bottom processing of the processing electrode and the enlargement processing by the side outer peripheral surface are simultaneously performed. In addition, jump operation
This is performed in order to relatively move the workpiece and the processing electrode mainly in the vertical direction or the vertical direction (Z-axis direction), and to discharge the processing waste generated between the poles by the pumping action therefrom. That is, the machining electrode is moved relatively vertically or vertically with respect to the workpiece, and the working liquid flows into the gap by separating the gap between the workpiece and the machining electrode. , The working fluid containing the processing waste is pushed out from the gap and discharged. Therefore, the moving distance is much larger than the swing or the machining feed.

[0005] Further, in the swinging operation in which the swinging operation is performed in the direction of the processing side surface to perform the enlarging processing in the direction of the processing side surface, machining chips are also generated between the processing side surface and the outer peripheral surface of the side of the processing electrode. , And easily adhere to the processing side surface. Therefore, in order to discharge the processing chips on the processing side surface from the gap, a jumping operation for greatly separating and approaching the processing electrode with respect to the processing side surface is performed together with the normal jump operation. For example, the processing electrode is relatively moved with respect to the workpiece in an oblique direction including the X-axis direction component and the Y-axis direction component together with the Z-axis direction component so as to be simultaneously separated and approached to the processing bottom surface and the processing side surface. Become. Rather than relatively moving the processing electrode along the processing side in this way, the processing electrode is relatively moved in an oblique direction away from the processing side, so that the processing electrode is processed from between the side outer peripheral surface and the processing side surface. The effect of discharging waste can be obtained.

[0006] By the way, the effect of discharging the machining waste by such a jump operation tends to increase as the jump speed is increased and the stroke is increased. Therefore,
In the swing machining, it is preferable to increase the angle between the moving axis of the machining electrode and the machining side surface. That is, it is preferable to increase the ratio of the horizontal component to the Z-axis component of the moving speed of the machining electrode. However, when the angle formed by the moving axis of the machining electrode and the machining side surface is increased, the stroke in the Z-axis direction is reduced, and the action of discharging the machining swarf by the jump operation to the machining bottom surface is reduced.
In order to solve this problem, the movement of the machining electrode combining the movement in the oblique direction and the movement in the Z-axis direction, such as performing the movement in the vertical direction, that is, the movement in the Z-axis direction after the movement in the oblique direction, is performed. May be done.

[0007] As a form of movement of the machining electrode combining the movement in the oblique direction and the movement in the Z-axis direction, see Japanese Unexamined Patent Publication No.
As described in JP-A-118149, there is an apparatus that jumps in a cycle by passing through different paths when jumping up and when jumping down. In addition, there are some jump operations in such rocking processing that take various trajectories, but in any case, the position of the processing electrode is made the same at the start and end of the jump. You.

[0008]

However, there are some problems when the above-mentioned rocking processing is performed. First, in the swing machining, as described above, in order to discharge machining waste from the gap between the machining side surface of the work and the side outer peripheral surface of the machining electrode, a horizontal movement component (vertical direction or Z axis) is used. (A direction component perpendicular to the direction). The effect of the discharge of machining debris by the jump operation increases as the jump speed increases. Becomes larger. This impact force causes unpleasant sounds and causes the machine to vibrate.

[0009] As a solution to this sound or vibration, it is common to perform an acceleration / deceleration control at a turning point, a start point, and an end point of a jump operation in which vibration occurs to reduce the impact force. Further, as disclosed in Japanese Patent Publication No. 4-31806, there is an electric discharge machining apparatus that switches a moving speed (jump speed) of a machining electrode with respect to a workpiece in accordance with a gap between the workpiece and the machining electrode, and switches to a lower speed when it is close.

However, if the machining electrode takes a jump trajectory that moves in the Z-axis direction after moving in the oblique direction in order to secure a stroke in the Z-axis direction, the switching direction of the machining electrode may be changed. Similarly, sound or vibration is generated by an impact on the inertial force. Therefore, when the relative movement direction is switched during one jump, acceleration / deceleration control is required before and after the switching point of the movement direction. In addition, the electric discharge machining apparatus disclosed in Japanese Patent Publication No. 4-31806 switches the speed depending on the distance between the workpiece and the machining electrode, and thus has no effect on the vibration generated at the switching point of the jump direction.

Here, FIGS. 11 and 12 show external views of the machine main body of the electric discharge machine, and the vibration of the machine will be described. FIG. 11 shows the work table 2 fixed and the machining electrode 15
FIG. 12 is an external view of a so-called ram-type electric discharge machine which moves the workpiece table 3 in the X, Y and Z directions, and FIG. 12 moves the work table 3 in the X and Y directions and the machining electrode 15 in the Z direction. FIG. 1 is an external view of a so-called table moving type electric discharge machine.

In any case, the movement of the machining electrode 15 in the Z-axis direction is performed by moving the main shaft 7 up and down by a Z-axis servomotor disposed inside the machine head 6, so that the moving part is lightweight and high-speed. It is unlikely that the machine will vibrate or make abnormal sounds even if it is moved. However, when the machining electrode 15 and the work 13 are relatively moved in the horizontal direction, a heavy portion is moved in any of the mechanical forms. For example, in FIG. 11, when the saddle 4 is moved in the X-axis direction, the saddle 4 is moved by the X-axis servo motor 17, and the saddle 4 is loaded with the ram 5 and the mechanical head 6 in combination, so that an extremely large weight is applied. Will move. Y
In the axial movement, the heavy ram 5 and the mechanical head 6 are moved by a Y-axis servomotor (not shown).

The movement in the X and Y axis directions in FIG.
The saddle 9 is moved by the axis servomotor 19, and the moving table 8 is moved by the X-axis servomotor 17. Also in this case, the movement in the X and Y axis directions moves a heavy part. By the way, in the electric discharge machining while performing the jump operation, when the jump speed is increased, the time required for the jump operation is shortened, and the discharge of machining waste from the gap between the machining electrode 15 and the work 13 is efficiently performed. As described above, the processing efficiency is improved.

However, when the jump operation is started during the swing machining, the machining electrode 15 is at a position eccentric with respect to the workpiece 13 from the machining center axis. Therefore, the side surface of the machining electrode 15 is close to the work 13 or the machining electrode 15 is
3, and if the processing electrode 15 is pulled up as it is, the processing electrode 15 may be damaged,
The machining electrode 15 and the work 13 interfere with each other. In order to avoid such inconvenience, the work electrode 15 is returned to the center and then lifted, or the ascending jump operation is performed while returning the work electrode 15 to the center.

[0015] In the case of a jump operation involving movement in the X-axis or Y-axis direction as described above, if movement starts at a high speed from the start of the jump operation, a large heavy object moved in the X-axis or Y-axis may be impacted. When the movement is started or stopped, the whole machine vibrates or generates an unpleasant abnormal sound. Also, when a diagonal jump operation is involved, the movement distance of the diagonal movement with the horizontal movement component is often shorter than the Z-axis movement distance,
It is difficult to secure a sufficient distance required for acceleration / deceleration control in the horizontal direction.

Therefore, the moving speed of the machining electrode may be kept low only when the machining electrode moves in the horizontal direction with respect to the workpiece, and when the machining electrode performs only the relative movement in the Z-axis direction, the moving speed is reduced. Need not be suppressed.
However, when the acceleration / deceleration control is performed, the jump speed in the steady state is constant regardless of the direction, and the jump speed is set to such a degree that the mechanical vibration due to the impact force does not matter. Further, performing acceleration / deceleration control of the moving speed of the machining electrode irrespective of the moving direction unnecessarily lengthens the time required for the jump and prolongs the electric discharge machining time.

As described above, when the jump start point and the end point are the same, abnormal machining due to concentrated discharge is likely to occur, and the machining surface of the work may be damaged, or the electrodes may be worn out. A second problem occurs in that the accuracy is reduced. In order to prevent such deterioration of machining accuracy due to damage to the workpiece and consumption of machining electrodes, a method of suppressing the total discharge energy by extending a pause time of a pulse voltage to be supplied so that the discharge is not concentrated on the same place. Used.
There is another problem that the machining efficiency is reduced and the machining time is prolonged because the amount of electric discharge machining is reduced accordingly.

Accordingly, it is an object of the present invention to suppress an increase in the predetermined time of the jump and to prevent a machine impact sound or vibration generated at the start and end of the high-speed jump operation, when the jump operation is turned back or when the direction is switched. That is. Another object of the present invention is to prevent a machining electrode from locally causing a concentrated discharge even when a pause time of a pulse voltage is reduced in a swing machining performed in an electric discharge machining, so that a stable discharge is achieved. And to improve the processing efficiency.

[0019]

SUMMARY OF THE INVENTION In view of the above-mentioned object, the present invention provides an electric discharge machine and a jumper of the electric discharge machine which can change a jump speed in a high-speed jump operation in accordance with a jump direction of a machining electrode. A control method is provided. Further, the present invention further provides an electric discharge machine and a jump control method of the electric discharge machine, which can change a position on a swing locus of a machining electrode before and after a jump operation.

That is, according to the present invention, a pulse voltage is applied between the electrode of the machining electrode and the work to perform the electric discharge machining on the work, and the electric discharge machining for causing the machining electrode to perform a jump operation in response to a jump request. In the electric discharge machine, there is provided an electric discharge machine comprising jump operation control means for setting different jump speeds when the direction of the jump operation of the machining electrode includes a horizontal component and when the direction of the machining electrode includes only a vertical component.

Further, according to the present invention, a pulse voltage is applied between the electrode of the machining electrode and the workpiece to perform the electrical discharge machining on the workpiece, and the electrical discharge machining for causing the machining electrode to perform a jump operation in response to a jump request. In the electric discharge machine, there is provided an electric discharge machine comprising a jump operation control means for setting an end position of the jump operation of the machining electrode at a position different from a start position of the jump operation of the machining electrode.

Also, the present invention provides an electric discharge machine which applies a pulse voltage between a machining electrode and a work to perform electric discharge machining on the work and performs a jump operation on the machining electrode in response to a jump request. In the jump control method, there is provided a jump control method for an electric discharge machine that sets different jump speeds when a direction of a jump operation of the machining electrode includes a horizontal component and a vertical component only.

Preferably, in the jump control method, the jump speed when the direction of the jump operation of the processing electrode includes a horizontal component is set lower than the jump speed when only the vertical component is included. The present invention further provides a jump control method for an electric discharge machine, which applies a pulse voltage between a pole between a machining electrode and a work to perform electric discharge machining on the work, and causes the machining electrode to perform a jump operation in response to a jump request. And a jump control method for an electric discharge machine, wherein an end position of the machining electrode jump operation is set to a position different from a start position of the machining electrode jump operation.

Preferably, in the jump control method,
Determining a swing trajectory of the machining electrode with respect to the workpiece, setting a first position on the determined swing trajectory as a start position of the jump operation of the machining electrode, and setting a start position of the jump operation and at least the jump operation Excluding the position adjacent to the start position of, the second position is set as the end position of the jump operation on the determined swing locus, and the workpiece is subjected to electrical discharge machining while swinging the machining electrode, In response to a jump request, the processing electrode is caused to perform a jump operation from a first position that is a start position of the jump operation to a second position that is the end position, and the second position is set as the first position. The jump operation is repeated so that the movement trajectory of the machining electrode is controlled to be the predetermined swing trajectory.

By setting different jump speeds when the direction of the jump operation of the machining electrode includes the horizontal component and when the direction of the machining electrode includes only the vertical component, discharge occurs when the machining electrode is started / stopped, turned back, and turned. It is possible to switch the jump speed between the horizontal direction where sound and vibration due to the impact force generated by the processing machine are likely to occur and the vertical direction where vibration is unlikely to occur, suppress the impact force, and reduce the sound and vibration . At the same time, it is not necessary to set the jump speed low in accordance with the movement including the horizontal movement in which vibration is likely to occur when the direction change is included during the jump operation, and it is not necessary to apply the jump speed to the entire jump operation. When the operation is only the vertical component, the jump speed can be set high, so that the time required for the jump operation can be reduced, and the effect of improving the processing efficiency can be obtained.

Further, by setting the end position of the jump operation at a position different from the jump start position at the time of the jump operation of the machining electrode in the swinging operation, the side portion of the machining electrode used before the jump operation is set. The outer peripheral surface portion that is different from the outer peripheral surface portion is used after the jump operation, and has the effect of discharging the machining debris attached to and floating on the side outer peripheral surface portion of the machining electrode used before the jump operation after the jump operation. This has the effect of preventing susceptibility to damage due to continuous concentrated discharge on substantially the same portion of the machining electrode before and after the jump operation, and the machining accuracy due to damage to the workpiece or consumption of the machining electrode. Can be reduced.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration block diagram showing a main part of an electric discharge machine according to the present invention. Here, the electric discharge machine shown in FIG.
Is a so-called ram-type electric discharge machine that moves in the X, Y and Z axis directions. The electric discharge machine shown in FIG. 12 moves the work table 3 in the X and Y axis directions and moves the machining electrode 15 in the Z axis direction. This is a so-called table moving type EDM that moves in the direction.

The electric discharge machine 11 discharges the work 13 by electric discharge.
Electrodes 15 for processing the
X-axis feed motor 17 and Z-axis feed motor 2 for moving the machining electrode 15 with respect to three axes, namely, an axis, a Z axis which is a vertical direction, and a Y axis which is a direction perpendicular to both the X axis and the Z axis.
1. Y-axis feed motor 19, each axis feed motor 17, 19,
And each of the axis feed motors 17, 19, 2
Moving means 2 including driving means 23 for supplying driving power to the driving means 1
5 is provided. The work 13 is placed in a processing tank (not shown) and is immersed in a processing liquid filled in the processing tank.

Each of the shaft feed motors 17, 19 and 21 is generally used in combination with a ball screw (not shown).
It is connected to the machine head 6 that supports the processing electrode 15 and moves the processing electrode 15. In the embodiment shown in FIG. 1, the processing electrode 15 is shown to be moved with respect to the work 13 by the moving means 25, but the processing electrode 15 and the work 13 can be relatively moved. The moving means 25 may move one or both of the head supporting the processing electrode 15 and the work table 3 on which the processing tank is placed as required.
For example, as shown in FIG.
5, the head may be moved in the Z-axis direction, and the table may be moved in the X-axis and the Y-axis. In addition, each axis feed motor 1
Servo motors are preferably used as 7, 19 and 21.

As shown in FIG. 1, each axis feed motor 1
When the moving means 25 including 7, 19, 21 and a ball screw (not shown) is attached to the head supporting the machining electrode 15, the Z-axis feed motor 21 moves the machining electrode 15 with respect to the workpiece 13 in the machining direction. Send or evacuate to The X-axis feed motor 17 and the Y-axis feed motor 19 move the machining electrode 15 in two axes directions orthogonal to each other on a plane perpendicular to the machining progress direction. Thus, the X-axis feed motor 1
7 and the movement by the Y-axis feed motor 19, the machining electrode 15 can be caused to perform a two-dimensional oscillating motion relative to the work 13, and furthermore, the X-axis feed motor 17, the Y-axis feed motor 19, and the Z-axis feed motor 19 By combining movements of the shaft feed motor 21, the machining electrode 15 can be three-dimensionally rocked relative to the work 13.

The electric discharge machine 11 is electrically connected to the workpiece 13 and the machining electrode 15, and has a machining power supply 27 for applying electric energy (voltage or current) therebetween, and a numerical value for controlling the operation of the driving means 23 and the machining power supply 27. And a control unit 29. Voltage detecting means 31 is connected in the middle of each wiring from the processing power supply 27 to the workpiece 13 and the processing electrode 15 to detect a voltage between the workpiece 13 and the processing electrode 15. By detecting the voltage between the electrodes by the voltage detecting means 31, the numerical control means 29 controls the processing gap between the workpiece 13 and the processing electrode 15 so that the voltage between the electrodes becomes constant.

This numerical control means 29 is
3, jump operation control means 35, swing control means 37
It is comprised including. The machining control means 33 controls the machining of the workpiece 13 while controlling the gap voltage between the workpiece 13 and the machining electrode 15 so as to keep the voltage between the electrodes detected by the voltage detecting means 31 constant. The electrode 15 is relatively moved.

On the other hand, the jumping operation control means 35 moves the machining electrode 15 in the Z-axis direction (vertical direction) with respect to the machining bottom surface in order to discharge machining debris interposed between the work 13 and the machining electrode 15. 2), the reciprocating motion is performed in the X-axis and Y-axis directions with respect to the processing side surface. This reciprocating movement, that is, the jumping operation is not always performed, but is performed at regular intervals by a jump timer, and in this case, the processing is temporarily interrupted.

Further, the swing control means 37 moves the machining electrode 15 with respect to the workpiece 13 together with the above-described relative movement in the vertical direction.
Is controlled so as to be eccentrically moved in the processing side direction (in a plane perpendicular to the Z-axis direction), so that enlargement processing in the side direction, that is, rocking processing is performed. In the swing machining performed in this manner, the machining electrode 15 is moved along a predetermined locus by the swing control means 37. This swing trajectory is typically circular, but triangular, square, or any other form may be employed as appropriate.

The electric discharge machine 11 of the present invention further includes an input means 39 for inputting a machining command or machining information such as a machining program, and a memory 41 for storing the inputted machining command or the like. In this memory 41, a processing condition table is set and stored in advance. In one embodiment, the jump operation control means 35 includes the machining electrode 15.
2B, when the horizontal direction component is included in the direction of the jump operation from the swing trajectory 43 as shown in FIG. 2B, as shown in FIG. The direction of the jump operation from the swing trajectory 43 is caused to cause the machining electrode 15 to perform the jump operation at a lower jump speed as compared with only the vertical component. Therefore, when the direction of the jump operation from the swing trajectory 43 as shown in FIG. 2C is switched in the middle, the jump speed is suppressed low while the horizontal direction component is included in the direction of the jump operation.
When the horizontal direction component is not included in the direction of the jump operation, the jump speed of the machining electrode 15 is controlled and switched so that the jump speed increases. By doing so, it is possible to reduce the noise and vibration caused by the impact force due to the inertial force at the movement start / end points, direction switching points, and turning points that occur when the movement including the horizontal direction component is performed, and to reduce only the vertical direction component. When moving, it is possible to move at a speed as fast as possible to suppress an increase in the time required for jumping.

In FIGS. 2B and 2C, the machining electrode 15 jumps toward a point on an axis extending vertically through the center of the swing trajectory 43. It is not necessary to pass through a point, and it is not necessary to converge the jump operation toward one point. In another embodiment, as shown in FIGS. 3A to 3C, the jump operation control means 35 controls the operation of the machining electrode 15 so that the swinging operation of the machining electrode 15 is performed during the swing machining. The machining electrode 15 is caused to jump from the jump start position on the moving trajectory 43,
The swing locus 43 deviated to some extent from this jump start position
The processing electrode 15 is lowered and returned to another upper position. Such a jump operation is repeated, and finally the machining electrode 15
The jump end position is selected and set such that all positions on the swing locus 43 are uniformly processed. By controlling the jump operation in this manner, only a part of the side outer peripheral surface of the machining electrode 15 is not intensively used at the time of rocking processing, and another part of the side outer peripheral surface is used. During this operation, there is an effect that the processing chips are discharged from the already used portion of the side outer peripheral surface of the processing electrode 15.

Next, taking the case where the machining electrode 15 moves along an oscillating trajectory 43 such as a circular shape as an example,
The operation at the time of swing machining in the electric discharge machine 11 of the present invention will be described. It goes without saying that the present invention is not limited to a circular swing locus. FIG. 4 is a flowchart showing the overall flow of the electric discharge machining by the electric discharge machine 11 of the present invention.

First, in step 51, a jump interrupt timer (hereinafter referred to as one of the jump operation settings) is set.
The setting of processing conditions including the setting of a jump timer) and the presence or absence of rocking processing is performed via the input means 39. These settings are stored in the memory 41. Here, description will be made assuming that swing processing is performed. The setting of the jump timer includes a jump cycle when the jump operation is performed periodically, a set voltage when the jump operation is performed when the voltage between the electrodes becomes equal to or less than the set voltage, and the like.

After all necessary settings have been made, electric discharge machining is started in step 53. At this time, the swing machining, which is an enlargement machining in the lateral direction of the machining electrode 15, is performed together with the electric discharge machining performed in the vertical direction. While the electric discharge machining is being performed, the jump timer shown in step 55 is sequentially interrupted according to the cycle of the jump operation set in step 51 and the set voltage. The interrupt of the jump timer will be described later in detail.

While the electric discharge machining is being performed, the voltage between the electrodes is further detected by the voltage detecting means 31 and smoothed (step 57), and the smoothed electrode voltage is compared with a preset reference value. Is performed (step 59). If this is higher than the reference value, the Z-axis feed motor 21 is driven via the driving means 23 to relatively advance the machining electrode 15 toward the work 13 (step 61). If this is lower than the reference value, the Z-axis feed motor 21 is driven via the driving means 23 to move the machining electrode 15 relatively backward from the work 13 (step 63). The amount of retreat is determined by the processing control means 33 of the numerical control means 29 according to the difference between the reference value and the detected value of the voltage between contacts. In the case of swing machining, these forward and backward movements are performed simultaneously with the eccentric movement of the machining electrode 15, and the X-axis and Y-axis feed motors 17, 19 are driven via the driving means 23, so that the machining electrode 15 is eccentric. A horizontal swing is also performed by moving the amount forward or backward.

The above steps 55 to 63 are continued until the machining electrode 15 reaches the machining completion position (step 65). Steps 53 to 65 except for step 55 are performed by the processing control means 33 for the feed of the processing electrode 15 in the vertical direction, that is, for the processing feed, and for the feed of the processing electrode 15 in the horizontal direction, that is, for the swing. This is performed by the motion control means 37. On the other hand, regarding step 55, the jump operation control means 35
Done by

Next, the form of step 55 of the interrupt of the jump timer which is the subject of the present invention will be described in detail. FIGS. 5 and 6 show a jump operation control means 35 for controlling the speed of the jump operation according to the direction of the jump.
FIG. 7 is a flowchart of the operation of the electric discharge machine 11 according to the first embodiment of the present invention, and FIG. 7 is a more detailed flowchart of the step of setting or changing the jump direction shown in FIGS.

The form of the jump operation of the machining electrode 15 is shown in FIG.
Is specified in advance in step 51. 8A, the processing electrode 15 jumps in the vertical direction, that is, the Z-axis direction. As shown in FIG. 8B, the processing electrode 15 moves in the X-axis direction. A form of jumping in the diagonal direction including the directional component and the Y-axis direction component together with the Z-axis direction component, as shown in FIG. As shown in FIG. 8D, FIG. 8 shows a combination of the movement in the oblique direction and the movement in the Z-axis direction.
This is similar to (c), but includes a form in which a jump is made in a cycle through different passing points when the jump is rising and when the jump is falling. Of these jump modes, those that include a change in the jump direction include a method in which a point passing on the way is specified in addition to the normally specified jump top dead center position. A jump route designating method may be employed. Further, in the case of the jump form as shown in FIGS. 8C and 8D, the machining electrode 15 does not necessarily have to move on the axis passing through the swing center of the swing locus 43.

Hereinafter, the operation of the first embodiment of the electric discharge machine 11 of the present invention will be described by taking, as an example, one of the above-mentioned jump modes which includes a change in the jump direction.
When the jump timer is interrupted in step 55 in FIG. 4, the direction and speed of the jump operation are set in step 67 according to the specified jump operation mode. Application of electric energy from 27 to the work 13 and the processing electrode 15 is temporarily stopped, and a jump operation is started. The setting of the direction and speed of the jump operation in step 67 will be described later in detail.

Next, at step 71, the moving means 25 is moved in accordance with the jump direction and speed set at step 67.
Thereby, the machining electrode 15 is relatively moved with respect to the work 13. At this time, the relative position of the direction change position with respect to the jump start position of the machining electrode 15 is predetermined according to the form of the jump operation. Until the processing electrode 15 reaches the predetermined direction change position, the movement of the processing electrode 15 is continued at the speed and direction set in step 67 (step 73).

When a jump mode in which the direction is not changed, for example, a jump mode as shown in FIGS. 8A and 8B is selected, the process proceeds according to a path indicated by a dotted line 75. When the jump direction change position is reached, the jump direction and speed are set again in step 77, and in step 79, the moving means 25 moves the work 13 by the moving means 25 until the turning point is reached in accordance with the set jump direction and speed. The processing electrode 15 is relatively moved. When the machining electrode 15 reaches the turning point (step 81), the speed and direction command data are all multiplied by (−1), and the moving direction and the speed vector are set to be inverted (step 83).

Hereinafter, similarly, the processing electrode is moved by the moving means 25 in accordance with the set jump direction and speed until the processing electrode 15 reaches the predetermined direction change position (step 85). Upon reaching the direction change position (step 87), the jump direction and speed are set again to change the jump direction (step 89). Next, the processing means 15 is moved by the moving means 25 in accordance with the set jump direction and speed until the processing electrode 15 reaches the jump start position (step 91). If it is determined in step 93 that the machining electrode 15 has reached the jump start position, the jump operation ends, and the jump timer is reset (step 95).

When the jump mode in which the direction is not changed is selected, as in the case described above, the dotted line 9
The processing proceeds along 7. In the following, FIGS. 5 and 6
The procedure for setting the jump direction and speed performed in steps 67, 77 and 89 will be described in more detail with reference to the flowchart of FIG.

First, in step 97, a jump direction is set in accordance with a predetermined jump operation mode. If the jump operation has already been performed, that is, in the case of steps 77 and 89, step 97
Changes the setting of the jump direction. Next, it is determined in step 99 whether the set jump direction includes an X-axis direction component or a Y-axis direction component. FIG.
8 (c) and FIG. 8 (d)
When the machining electrode 15 moves only in the Z-axis direction in the jumping operation mode described above, the process proceeds to step 101. On the other hand, the jump operation mode shown in FIG.
8D, if the processing electrode 15 includes movement in the X-axis direction or the Y-axis direction, such as when the processing electrode 15 moves in an oblique direction, the process proceeds to step 103.

When the process proceeds to step 101, the jump speed is determined to be a predetermined relatively high speed J1 which is applied when only the Z-axis direction component is used. If the processing has proceeded to step 103, the component of the direction vector of the jump operation on the XY plane (the plane formed by the movement of the X axis component and the Y axis component, that is, the plane perpendicular to the Z axis) is Desired. This XY plane component is an orthogonal projection of the direction vector on the XY plane.

Next, the ratio between the magnitude of the XY plane component of the direction vector and the magnitude of the Z axis direction component of the direction vector is determined, and the jump speed is determined according to the ratio (step 105).
And step 107). In step 109, the determined jump speed is set in the jump operation control means 35. In detail, a jump speed J2 at which the machining electrode 15 moves in the XY plane direction (direction perpendicular to the Z axis) is determined in advance, and Z is determined according to the ratio α of the Z direction component to the XY direction component of the jump direction vector. The jump speed in the axial direction is determined as αJ2, and the overall jump speed is determined as J2 × √ (1 + α ² ) in accordance with the determined jump speed. Preferably, the jump speed J2 in the XY plane direction is lower than the jump speed J1 applied when the machining electrode 15 moves in the direction of only the vertical component, and the relative movement start / stop point and direction of the machining electrode 15 are set. The sound and the vibration generated in the electric discharge machine 11 at the switching point and the turning point are set to be suppressed to an appropriate level.

Therefore, if the form or the jump direction of the jump operation is set in step 51, the operator does not need to set the jump speed according to the form or the jump direction of the jump operation. Jump speed is automatically set. Further, even when the jump direction is switched as shown in FIGS. 8C and 8D, a suitable jump speed is automatically set according to the jump direction at that time, and only in the Z-axis direction. When the processing electrode 15 is relatively moved, a jump operation is performed at a relatively high jump speed, and when the movement includes a horizontal component, the jump operation is performed at a jump speed set so that the horizontal component of the movement speed is reduced. Therefore, the vibration of the electric discharge machine 11 at the start / stop point, the direction switching point, and the turning point of the machining electrode 15 is reduced.

Alternatively, if the movement of the machining electrode 15 by the jump operation includes a horizontal component, step 1
Instead of 03, 105, and 107, the jump speed J2 'may be set regardless of the jump direction (however, when the movement of the machining electrode 15 by the jump operation is only the Z-axis component, the jump speed is J1). In this case, the jump speed J2 'is the impact sound of the electric discharge machine 11 generated at the start / stop point, direction switching point, and turning point of the machining electrode 15, assuming that the jump operation includes only the horizontal component. It is preferable that the vibration and the vibration are set low enough not to cause discomfort.

Similarly, it is also possible to divide the ratio between the XY plane direction component and the Z-axis direction component of the direction vector into several stages so that the same jump speed J2 'is set in each of the stages. is there. It is also possible to use another arbitrary method for setting different jump speeds depending on the jump direction.

FIG. 9 relates to a second embodiment of the electric discharge machine 11 of the present invention which comprises jump operation control means for setting a jump operation end position to a position shifted from a jump start position on a swing locus of a machining electrode. FIG. 10 is a flowchart of the operation, and FIG. 10 is a more detailed flowchart of the step of setting the jump end position shown in FIG.

The interruption of the jump timer in step 55 of FIG.
In step 1, the application of electric energy from the processing power supply 27 to the workpiece 13 and the processing electrode 15 is temporarily stopped by the numerical control means 29, the direction and speed of the jump operation are set, and the jump operation is started. Next, in step 113, the machining means 15 relatively moves the machining electrode 15 with respect to the workpiece 13 by the moving means 25, that is, performs a jump operation in accordance with the setting of the jump direction and the speed set in step 111. At this time, the relative position of the turning position with respect to the jump start position of the machining electrode 15 is predetermined. The movement of the processing electrode 15 is continued until the processing electrode 15 reaches a predetermined turning position (step 115).

When the turning position is reached, step 117 is reached.
, A jump end position different from the jump start position is set, and the jump direction and speed are set again accordingly. The end position is selected as far as possible from the jump start position. The selection of the end position will be described later in detail. In step 119, the machining means 15 is moved relative to the work 13 by the moving means 25 until the processing electrode 15 reaches the jump end position in accordance with the set jump direction and speed. If it is determined in step 121 that the machining electrode 15 has reached the end position, the jump operation ends in step 123, and the jump timer is reset. At the same time, the work 13 is
Then, the application of the electric energy to the processing electrode 15 is restarted.

Hereinafter, the procedure for selecting the end position of the machining electrode 15 performed in step 117 of FIG. 9 will be described in more detail with reference to the flowchart of FIG. First, a preset oscillating trajectory 43 of the machining electrode 15 is equally divided by a predetermined number to create a candidate point of an end position. When the jump operation is started, the jump operation control unit 35 refers to the created jump end position candidate point in step 125.

Next, in step 127, it is determined whether all the candidate points of the jump end position have been used. If all the candidate points have been used, in step 129, all the candidate points of the used end position are cleared. Then, initialization is performed so that all candidate points are treated as unused points. If any of the candidate points is treated as unused, the process proceeds to step 131, and a candidate point at an end position that is somewhat distant from the start position of the ongoing jump operation is selected. By selecting the end position that is somewhat far from the start position of the jump operation, the machining electrode 1 is set before and after the jump.
Since the portion used in the swing machining of the outer peripheral surface of the side 5 is different, it is used before the jump operation while performing the electric discharge machining using the other outer peripheral surface of the side. This has the effect of discharging the machining debris from the outer peripheral surface of the side portion, thereby making it possible to suppress damage to the work 13 and consumption of the machining electrode 15.

In step 133, it is confirmed whether or not the selected candidate point has been used. If the candidate point has been used, the process returns to step 131 again to select a candidate point. When it is confirmed that a candidate point that can be treated as unused is selected, in step 135, the servo block is changed to change the jump end position. In this servo block, start point information and end point information relating to movement are set, and by changing this information, the machining electrode 1 is moved to a new jump end position.
5 moves, and the setting of the jump end position ends.

By continuing the jump operation in this way, all the candidate points of the end position on the swinging trajectory 43 of the machining electrode 15 are uniformly selected.
The swing processing is performed evenly on the work 13 on the swing trajectory. Note that the swing locus 43 is equally divided into a large number, and each section may be configured as a very small one, that is, a point.

The control of these jump operations is performed by the numerical control means 29, mainly the jump operation control means 35. Although the two forms of the jump operation control means shown above are shown as different forms, it goes without saying that these can be performed simultaneously.

[0063]

As described above, according to the present invention,
In oscillating machining, the jump speed can be automatically set by changing the jump speed according to the direction of the jumping operation. Therefore, when the movement of the machining electrode includes a horizontal component, the horizontal component of the speed is kept low, and the machining electrode is started. -It is possible to reduce unpleasant noises and vibrations of the electric discharge machine generated at the stopping point, the direction switching point, and the turning point, thereby improving machining accuracy.

Further, by changing the position of the machining electrode on the swinging trajectory before and after the jump operation, it is possible to avoid a concentrated discharge that continuously generates electric discharge machining only at a specific portion of the machining electrode, and to use the electric discharge machining before the jump operation. By exerting the effect of ejecting the processing debris after the jumping operation of the set portion, it is possible to suppress damage to the work and consumption of the processing electrode. By suppressing the damage of the workpiece and the consumption of the processing electrode, the processing accuracy is improved.

Further, since it is possible to apply a large electric energy to the processing electrode, it is possible to obtain an effect that the processing time can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram showing a main part of an electric discharge machine according to the present invention.

FIG. 2 is a schematic diagram for explaining that a jump operation control means controls a jump operation of a machining electrode so as to change a jump speed according to a jump direction.

FIG. 3 is a schematic diagram for explaining that the jump operation control means controls the jump operation of the processing electrode so as to change the position of the processing electrode before and after the jump operation.

FIG. 4 is a flowchart showing the overall flow of electric discharge machining by the electric discharge machine of the present invention.

FIG. 5 is a first half of a flowchart of an operation of the electric discharge machine according to the first embodiment of the present invention in which a jump operation control means is configured to control a speed of the jump operation according to a jump direction.

FIG. 6 is a latter half of the flowchart shown in FIG. 5;

FIG. 7 is a more detailed flowchart of steps for setting or changing a jump direction shown in FIGS. 5 and 6;

FIG. 8 is a diagram showing some forms of a jump operation.

FIG. 9 is a flowchart of the operation of a second embodiment of the electric discharge machine according to the present invention, which comprises a jump operation control means for setting a jump operation end position at a position distant from a jump start position on a swing locus of the machining electrode. It is.

FIG. 10 is a more detailed flowchart of a step of setting a jump end position shown in FIG. 9;

FIG. 11 is an external view of a ram-type electric discharge machine.

FIG. 12 is an external view of a table moving type electric discharge machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Electric discharge machine 13 ... Work 15 ... Machining electrode 25 ... Moving means 33 ... Machining control means 35 ... Jump operation control means 37 ... Swing control means

Claims (6)

[Claims] 1. An electric discharge machine for applying a pulse voltage between a pole between a machining electrode and a work to perform electric discharge machining on the work and to cause the machining electrode to perform a jump operation in response to a jump request. An electric discharge machine comprising a jump operation control means for setting different jump speeds when the direction of the jump operation includes a horizontal direction component and when the direction of the jump operation includes only a vertical direction component. 2. An electric discharge machine for applying a pulse voltage between a machining electrode and a workpiece to perform electrical discharge machining on the workpiece and to cause the machining electrode to perform a jump operation in response to a jump request. An electric discharge machine comprising a jump operation control means for setting an end position of a jump operation of the machining electrode at a position different from a start position of the jump operation. 3. A jump control method for an electric discharge machine in which a pulse voltage is applied between an electrode of a machining electrode and a workpiece to perform electrical discharge machining on the workpiece and cause the machining electrode to perform a jump operation in response to a jump request. A jump control method for an electric discharge machine, wherein different jump speeds are set when a direction of a jump operation of the machining electrode includes a horizontal direction component and when a vertical direction component alone is included. 4. The jump control method for an electric discharge machine according to claim 3, wherein a jump speed when the direction of the jump operation of the machining electrode includes a horizontal component is set lower than a jump speed when only a vertical component is included. . 5. A jump control method for an electric discharge machine in which a pulse voltage is applied between a machining electrode and a workpiece to perform electrical discharge machining on the workpiece and cause the machining electrode to perform a jump operation in response to a jump request. A jump control method for an electric discharge machine, wherein an end position of a jump operation of the machining electrode is set to a position different from a start position of a jump operation of the machining electrode. 6. A swing locus of the machining electrode with respect to the workpiece is set, a first position is set on the determined swing locus as a start position of a jump operation of the machining electrode, and a start position of the jump operation is set. And setting a second position as an end position of the jump operation on the determined swing trajectory, except for at least a position adjacent to a start position of the jump operation. Performing electric discharge machining, and causing the machining electrode to perform a jump operation from a first position, which is a start position of the jump operation, to a second position, which is the end position, in response to a jump request; The jump control method for an electric discharge machine according to claim 5, wherein a jump operation is repeated as the first position, and control is performed such that a movement locus of the machining electrode becomes the determined swing locus.