JPH0716821B2 - Electric discharge machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric discharge machine, and more particularly to control of an electrode jumping motion for discharging a machining powder.

[Prior Art] Japanese Patent Application Laid-Open No. 51-47695 discloses a conventional example of controlling the jumping motion of an electrode for discharging a processed powder.

The one disclosed in JP-A-51-47695 discloses that when machining powder is deposited between the electrodes during one-proximity machining (a period during which the jumping motion of the electrode is paused), the electrode undergoes one-proximity machining. Focusing on the fact that the electrode rises from the deepest position of the electrode, the jump motion of the electrode is performed when the electrode rises from the deepest position of the electrode during the one-proximity machining by a predetermined electrode return amount.

However, since the conventional one is configured as described above, there are the following problems.

That is, it is often the case that the machining powder discharge capacity is insufficient due to a failure in setting jump conditions and the electrodes do not return to a position where machining is sufficiently advanced even when the electrodes perform a jump motion.

In such a case, the conventional one described above does not perform the jump motion of the electrode until the electrode is moved up to the predetermined electrode return amount from the deepest position of the electrode during one-proximity processing, so that the electrode is not sufficiently processed. Even though it has not returned to the position where it advances, the machining is continued in that state, and there is a drawback that the machining does not proceed sufficiently.

The present invention has been made in view of the above-mentioned problems, and provides an electric discharge machining apparatus capable of immediately changing jump conditions when the electrode does not return to a position where machining is sufficiently advanced even if the electrode makes a jump motion. To do.

[Means for Solving the Problems] An electric discharge machining apparatus according to the present invention is an electrode descent position storage unit that stores an electrode descent position during the most recent jump motion, and a jump motion from the start of machining to the most recent jump motion. Deepest position storage means for storing the deepest position where the electrode has descended, and the electrode jump position during the latest jump movement stored in the electrode drop position storage means and the latest jump from the machining start stored in the deepest position storage means. Calculation means for calculating the difference between the deepest position where the electrode has fallen during the jumping movement up to the movement, each machining powder quantity limit value storage means for storing each machining powder quantity limit value according to each machining condition, and machining Processing powder quantity limit value that stores the optimum processing powder quantity limit value selected from each processing powder quantity limit value corresponding to each processing condition stored in each processing powder quantity limit value storage means according to the condition Boundary value storage means, comparing the difference calculated by the calculation means and the processed powder quantity limit value stored in the processed powder quantity limit value storage means, and when the difference exceeds the processed powder quantity limit value , And a comparing means for outputting a signal for changing the jump condition.

[Operation] In the electric discharge machining apparatus according to the present invention, if the electrode does not return to the position where machining proceeds sufficiently even if the electrode makes a jump movement, the electrode makes a jump movement immediately.

[Embodiment of the Invention] A first embodiment of the present invention will be described below with reference to FIGS. 5, 6, 3, and 4.

That is, in FIG. 5, (1) is the first memory which is the electrode descending position storage means for storing the electrode descending position during the most recent jumping motion, and (2) is the jump from the start of machining to the most recent jumping motion. A second memory, which is a deepest position storage means for storing the deepest position where the electrode is lowered during the movement,
(4) is the electrode descending position at the time of the latest jump motion stored in the first memory (1) and the jump motion from the start of machining stored in the second memory (2) to the latest jump motion. An adder which is a calculating means for calculating a difference from the deepest position where the electrode has fallen, and (3) is a third storing means for storing the difference calculated by the adder (3). A memory, (6) is a fourth memory for storing the processed powder amount limit value, and (5) is the fourth memory calculated by the adder (4) and stored in the third memory (3). The comparator is a comparator that compares the processed powder amount limit value stored in (6) and outputs a signal for changing the jump condition when the difference exceeds the processed powder amount limit value.

Next, the operation of this device will be described with reference to FIG. 5, FIG. 6, FIG. 3 and FIG.

That is, at the start of processing, the first memory (1), the second memory (2) and the third memory (3) are cleared.

When the machining is started and the first electrode jump movement is set by the user, the machining electrode position Δ1 at the end of the jump movement is stored in the first memory (1) and the second memory (2). . In the second and subsequent electrode jump movements, the electrode position Δh at the end of the deepest jump is always the first
Is stored in the memory (1), and at the same time, the electrode position Δh and the electrode deepest position Δk at the end of the jump motion performed in the past are compared by the comparator (5). By this comparison, when Δh <Δk, the electrode position Δh is regarded as the deepest position, and this is stored in the second memory (2). In the other cases, the adder (4) calculates the difference Δh-Δk = εh between the power feeding position Δh and the deepest position Δk, and the calculation result is stored in the third memory (3). That is, the contamination amount at the end of the jump motion most recently performed is always stored in the third memory (3).

On the other hand, the fourth memory (6) has a limit value H1 of the contamination amount, that is, a condition for changing the jump condition. The limit contamination amount has been entered. Further, when the data from the third memory (3) and the fourth memory (6) are input to the comparator (5) and the difference εh exceeds the limit value H1 of the contamination amount, thereafter, Changes the jump conditions.

The case where the difference εh exceeds the limit value H1 of the contamination amount is the case of the point A in FIG.
It is considered that a large amount of processed powder accumulated between the electrodes. It is clear that if left in this state, the processing speed drops rapidly as shown in FIG. Point A shown in FIG. 4 indicates the same point shown in FIG.

Further, the change of the jump condition described above is to change the jump condition set by the user to a jump condition that further improves the processing powder discharging effect.
Shortened to 2 and jumped with 4 times the jump amount set to 4
And so on.

Next, a second embodiment will be described with reference to FIGS. 1 and 2.

That is, in FIG. 1, (1) is a first memory which is an electrode descending position storing means for storing the electrode descending position during the most recent jumping motion, and (2) is a jump from the start of machining to the most recent jumping motion. A second memory, which is a deepest position storage means for storing the deepest position where the electrode is lowered during the movement,
(4) is the electrode descending position at the time of the most recent jump motion stored in the first memory (1) and the jump motion from the start of machining stored in the second memory (2) to the most recent jump motion. An adder which is a calculating means for calculating the difference from the deepest position where the electrode has fallen, and (3) is a third storing means for storing the difference calculated by the adder (4). A memory, (6) is a fifth memory which is each processing powder amount limit value storage means for storing each processing powder amount limit value according to each processing condition, and (7) is a sixth memory which stores processing conditions. (8) is the optimum selected from the respective processing powder amount limit values corresponding to the respective processing conditions stored in the fifth memory (6) based on the processing conditions stored in the sixth memory (7), A seventh memory, which is a processed powder amount limit value storage means for storing the processed powder amount limit value, ) Is the difference calculated by the adder (4) and stored in the third memory (3) and the optimum machining powder amount limit value according to the machining conditions stored in the seventh memory (8). The comparator is a comparator that outputs a signal for changing the jump condition when the difference exceeds the machining powder amount limit value.

Next, the operation of this device will be described with reference to FIGS.

That is, at the start of processing, the first memory (1), the second memory (2) and the third memory (3) are cleared.

When the machining is started and the first electrode jump movement is set by the user, the descending electrode position Δ1 at the end of the jump movement is stored in the first memory (1) and the second memory (2). . In the second and subsequent electrode jump movements, the electrode position Δh at the end of the deepest jump is always the first
Is stored in the memory (1) and is simultaneously compared with the electrode position Δh and the electrode deepest position Δk at the end of the jump motion performed in the past by the comparator (5). By this comparison, when Δh <Δk, the electrode position Δh is regarded as the deepest position, and this is stored in the second memory (2). In other cases, the adder (4) calculates the difference Δh−Δk = εh between the electrode position Δh and the deepest position Δk, and the calculation result is stored in the third memory (3). That is, the contamination amount at the end of the jump motion most recently performed is always stored in the third memory (3).

On the other hand, in the seventh memory (8), on the basis of the processing conditions stored in the sixth memory (7), the amount of each processing powder according to each processing condition stored in the fifth memory (6). The optimum machining powder amount limit value selected from the limit values, that is, the optimum contamination amount limit value H1 according to the processing conditions, that is, the limit contamination amount that is the condition for changing the jump condition is input. . Data from the third memory (3) and the seventh memory (8) is input to the comparator (5), and the difference εh is the limit value of the contamination amount.
When it exceeds H1, the jump condition is changed after that.

Regarding the number of memories to be used, the jump condition at the time of change, the logic circuit and the like shown in the above-mentioned embodiment, various widely known ones can be used within the scope of the present invention to make various changes. .

[Effects of the Invention] As described above, according to the present invention, the electrode descending position storage means for storing the electrode descending position during the most recent jumping motion and the electrode in the jumping motion from the start of machining to the most recent jumping motion. The deepest position storage means for storing the deepest position that has been lowered, the electrode descent position during the latest jump movement stored in the electrode lowering position storage means, and the machining start stored in the deepest position storage means until the latest jump movement. Calculation means for calculating the difference from the deepest position where the electrode has fallen in the jump motion up to, machining powder amount limit value storage means for storing each machining powder amount limit value according to each machining condition, and for each machining condition And a processed powder amount limit value storage means for storing an optimum processed powder amount limit value selected from each processed powder amount limit value according to each processing condition stored in each processed powder amount limit value storage means. Comparing the difference calculated by the calculating means with the processed powder quantity limit value stored in the processed powder quantity limit value storage means, and changing the jump condition when the difference exceeds the processed powder quantity limit value In addition to the above effect, it is possible to easily set the optimum machining powder amount limit value.

[Brief description of drawings]

FIG. 1 is a block diagram showing a second embodiment of the present invention, FIG. 2 is a flow chart for explaining the operation of the second embodiment of the present invention, and FIGS. 3 and 4 show an embodiment of the present invention. A graph for explaining such an operating principle and electrode jump movement,
FIG. 5 is a block diagram showing the first embodiment of the present invention, and FIG. 6 is a flow chart for explaining the operation of the first embodiment of the present invention. In the figure, the same or corresponding portions are shown, (1) is the first memory, (2) is the second memory, (3) is the third memory,
(4) is an adder, (5) is a comparator, (6) is the fourth
Or the fifth memory, (7) is the sixth memory,
(8) is a seventh memory.

Claims (1)

[Claims] 1. An electric discharge machining apparatus in which an electrode performs a jump motion at a desired time interval, an electrode descending position storage means for storing an electrode descending position at the time of the most recent jump motion, and from the start of machining to the most recent jump motion. From the start of machining stored in the deepest position storage means for storing the deepest position where the electrode has descended in the jump motion of Calculating means for calculating the difference between the deepest position where the electrode has descended in the jump motion up to the most recent jump motion, and each processed powder amount limit value storage means for storing each processed powder amount limit value according to each processing condition And the optimum processed powder amount limit value selected from the respective processed powder amount limit values corresponding to the respective processing conditions stored in the respective processed powder amount limit value storage means according to the processing conditions. And machining dust amount limit value storing means for 憶,
The difference calculated by the calculation means is compared with the machining powder quantity limit value stored in the machining powder quantity limit value storage means, and when the difference exceeds the machining powder quantity limit value, the jump condition is changed. An electric discharge machine comprising: a comparison means for outputting a signal.