JPH0626765B2 - Die-sinking EDM method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a die-sinking electric discharge machining method, and more particularly to a method for determining whether or not the coordinate value of an electrode is saturated.

[Prior Art] Conventionally, this type of device has been shown in the configuration diagram of FIG. It is equipped with motors (2), (3) for moving the machining table (1) in the X and Y directions and a motor (5) for moving the electrode (4) in the vertical Z direction. ), (3),
(5) is a numerical control device (6) (hereinafter referred to as NC device)
Controlled by.

In addition, a power supply for machining (8) is placed between the electrode (4) and the work (7).
A more pulsed voltage is applied, so that electric discharge machining is performed.

The machining power source (8) is controlled by the NC device (6), and each time the machining electrical condition is set by the operator, the NC device (6) sets the machining power source (8). The processing electric conditions can be switched.

The machining electric conditions determine the machining depth, clearance, etc. In order to maintain the optimum machining state, the machining electric conditions are determined for each machining process to maintain the optimum machining state and to obtain the desired roughness surface. To do.

For example, as shown in Fig. 4, the roughness (g) of the machining surface remaining in the rough machining step (a) is changed to the roughness (g / 2) by changing the machining electrical conditions in the next step (b). ), And the next step
In (c), (g / 4) is used, and in the final step (d), the desired shape is obtained.

Then, in each of these steps, the electrode is fed so as to have the surface roughness of that step.

However, in general, as shown in FIG.
It becomes saturated with the progress of processing in each process, the feed amount hardly changes, and it takes time to keep this state for a long time.

Further, when the feed amount is saturated to some extent, the value is generally close to the target surface roughness.

For this reason, the operator reads the feed amount from the dial gauge and plots it to determine whether the feed amount is saturated.

[Problems to be Solved by the Invention] Since the conventional device is configured as described above, in order to determine whether or not the electrode feed amount is saturated, a dial gauge is used to plot the electrode feed amount. However, there is a problem that the operator needs a lot of time for plotting.

The present invention has been made to solve the above problems, and an object thereof is to obtain a die-sinking electric discharge machining method capable of easily determining saturation without the operator having to plot the feed amount of the electrode by a dial gauge. To do.

[Means for Solving Problems] A die-sinking electric discharge machining method according to the present invention includes a step of detecting and storing the coordinate value of an electrode at regular time intervals, the stored previous coordinate value and the stored current coordinate value. And a step of comparing the amount of advance with a reference value to determine whether it is less than or equal to the reference value.
C device automatically determines that the coordinate values are saturated.

[Operation] In the present invention, the coordinate values of the electrodes are stored at regular intervals, and the difference between the stored previous coordinate value and the current coordinate value is used as the amount of advance and compared with the reference value. When N
The C device automatically determines that the coordinate values of the electrodes are saturated.

[Embodiment of the Invention] An embodiment of the present invention will be described below. FIG. 1 is a flow chart for explaining the operation. First, in step (S1), it is detected whether or not machining is in progress. If this is (yes), the process proceeds to the next step (S3).

Here, when a preset time has elapsed, (y
es), the coordinate values of each axis X, Y, Z are read in the next step (S5).

Then, of the read coordinate values, for example, for the Z-axis coordinate axis, the change amount from the previous Z-axis coordinate value is obtained, and this advance amount is stored in advance as the difference between the coordinate values of the electrodes, that is, the advance amount. It is determined whether it is smaller than or larger than the reference advance amount δ in this process (S7).

The reference advance amount δ serves as a reference value for determining saturation of the coordinate value of the electrode.

Then, if the obtained advance amount is smaller than the reference value Δ, it is determined to be (yes). That is, it is determined that the coordinate values of the electrodes are saturated.

Also, although not much related to the gist of the present invention,
In S9, the coordinate value of the relative movement axis and the machining electrical condition at this time are paired and stored in the memory, and are used in the next machining.

Further, when it is determined to be (no) in the above step (S1), the coordinate value is cleared in step (S11) and the process ends. Also, it goes without saying that the process ends when it is determined to be (no) in steps (S3) and (S7).

The flowchart of FIG. 1 shows the operation every time one pulse of the timing signal for determining the saturation of the coordinate value in the NC device is sent, and does not show the start to the end of machining. Therefore, ending means returning to the main program.

Next, the determination of the amount of advance will be described with reference to the drawings. Second
The figure is an explanatory view for explaining the amount of advance.

As shown in the figure, NC is the difference between the coordinate value of the electrode at this time and the coordinate value of the electrode at the previous time, and the amount of advance becomes smaller with the passage of time, and eventually becomes saturated.

The present invention automatically compares the advance amount with the reference value δ for determining the saturation each time the advance amount is obtained. Therefore, it is possible to easily know whether the coordinate values of the electrodes are saturated.

[Effect of the Invention] As described above, according to the present invention, the amount of advance of the electrode is calculated from the coordinate values of the electrode at constant time intervals, and the amount of advance of the electrode is compared with a reference value. By automatically determining that the coordinate value of is saturated, the operator can look at the dial gauge one by one and plot the electrode feed amount to determine whether the electrode feed is saturated or not. Therefore, it is possible to omit the plotting work of the worker.

Further, the saturation of the coordinate value becomes a different value every time the machining process is different, but if the electromachining conditions are the same, the advance amount δ
It will always be constant. Therefore, the effect that the automatic discrimination by the NC is easy is obtained.

[Brief description of drawings]

FIG. 1 is a flow chart for explaining an embodiment of the present invention,
FIG. 2 is an explanatory diagram for explaining the amount of advance, FIG. 3 is a configuration diagram of a conventional electric discharge machining apparatus, FIG. 4 is an explanatory diagram for explaining a machining process, and FIG. 5 is an explanation for explaining a feed amount of a dial gauge. It is a figure. In the figure, (1) is the machining table, (2) is the X-axis motor, (3) is the Y-axis motor, (4) is the electrode, (5) is the Z-axis motor, and (6) is the N-axis motor.
C device, (7) is a work piece, and (8) is a processing power source. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A step of detecting and storing a coordinate value of an electrode at regular time intervals, a step of obtaining a lead amount which is a difference between the stored last coordinate value and a present coordinate value, and the lead amount. With a reference value to determine whether or not the reference value or less, and when the determination result is less than or equal to the reference value, by the NC device,
And a step of automatically determining that the coordinate values are saturated.