JPS62114820A - Electric discharge machine - Google Patents

Abstract

PURPOSE:To make the basic data gathering of optimum machining ever so easy as well as to make it usable at a moment, by storing coordinate values of all axes during machining at every fixed time by means of a numerical control system, and judging a feed rate to machining electric conditions. CONSTITUTION:First, whether it is in machining or not is detected, and when YES is the case, each coordinate value of X, Y and Z is read by a step 13 after the elapse of the preset time by a step 11, and whether a variation with the coordinate value of the last time is smaller than the preset value or not is judged by a step 14. If it is smaller, the coordinate value at this time is set down to a feed rate and stored so as to correspond to 1 to 1 with machining electric conditions by a step 15, and when the machining electric condition is selected, this feed rate is used whereby optimum machining is performable. When NO is the case with a step 11, the coordinate value is cleared by a step 16, thus processing is over. Also when NO is the case with steps 12 and 14, it comes to an end as well.

Description

[Detailed description of the invention] [Industrial application field] In this invention, the electrodes are placed opposite to each other and are coated with each other.

The present invention relates to an electrical discharge machining device that applies voltage between workpieces to machine them.

[Conventional technology]

Conventionally, there has been a device of this type as shown in the block diagram of FIG. This consists of motors (2) and (3) that move the processing table (1) in the x and y directions, and two upper and lower electrodes (4).
These motors (2), (3), and (5) are controlled by a numerical control device (6) (hereinafter referred to as an NC device). Further, a pulsed voltage is applied between the electrode (4) and the workpiece (7) from a machining power source (8), thereby performing electrical discharge machining. The machining power source (8) is controlled by the NC device (6), and the machining electrical conditions are switched.

In the electrical discharge machining device with the above configuration, in order to maintain the optimum machining condition and perform electrical discharge machining into the desired shape,
It depends on many parameters such as machining depth, machining electrical conditions, clearance, and swing machining allowance. therefore,
It is extremely difficult to unambiguously determine this optimal value, and the current situation is that it relies on a lot of basic data and the intuition and experience of the operator.

In the past, manufacturers provided the above basic data as a recommended machining condition table as shown in Figure 3, but these data cannot be fully utilized if the electrode shape and area, material of the workpiece, etc. differ. I couldn't. Therefore, if a user wants to obtain optimal processing, it is necessary for the user to collect basic data suitable for the processing. The optimum machining here refers to the roughness (g) of the machined surface when machining in the rough machining step (a) as shown in Figure 4.
In the next step (b), the machining electrical conditions are changed to reduce the roughness to (g/2), and in the next step (C), the roughness is reduced to (g/4).
Then, in the final step (d), it is finished into the desired shape. At this time, it is necessary to select an appropriate feed rate; if the feed rate is small, a rough machined surface will remain and it will take a long time to process the next process. On the other hand, if the feed rate is large, the shape will be machined to a size larger than the desired shape.

[Problems that Q Ming attempts to solve Here, an example of the characteristics showing the relationship between time and processing amount (feed amount) for each processing condition is as shown in FIG.

In other words, if we plot the feed rate on the vertical axis and time on the horizontal axis in this characteristic diagram, it is clear from the diagram that the feed rate (machining progress) decreases significantly (saturates) as time passes. do. This is due to the sudden increase in the processing area. Therefore, the user has to spend a large amount of work and time to measure the point at which the feed rate reaches saturation while observing a dial gauge, etc., and to collect basic data at that point.

This invention was made to solve the above-mentioned problems, and it is an object of the invention to make it possible to collect basic data using the above-mentioned NC device.

[Means for solving problems]

The basic data collection method according to the present invention makes it possible to determine the feed rate for the machining electrical conditions and find the optimal conditions by storing the coordinate values of all axes during machining for a certain period of time fi. be.

[Effect]

The basic data collection method in this invention detects saturation in the progress of machining based on changes in stored coordinate values,
Measure the amount of feed at that time.

[Embodiments of the invention]

An embodiment of the present invention will be described below. FIG. 1 is a flowchart illustrating its operation. First, step (11
) to detect whether or not processing is in progress, and this indicates (yes).
), proceed to the next step (12). Here, when a preset certain period of time has elapsed, the answer is (yes), so in the next step (13), the coordinate values of each axis X, Y, and Z are read, and these are the previous coordinates in step (14). It is determined whether the change from the value is smaller than a preset value (δ). If the change in coordinate value is smaller than (δ), this is (yes), so the next step (1
Proceed to 5). At this time, the coordinate value at that time is set as the feed amount so that it corresponds one-to-one with the machining electrical conditions, and this is stored. Thereafter, when machining electrical conditions are selected, optimal machining can be performed by automatically using the feed amount determined in the above process. Note that the above steps.

If it is determined (no) in (11), step (
In step 16), the coordinate values are cleared and the process ends. It goes without saying that the process also ends when the determination in steps (12) and (I4) is (no).

In the above embodiment, all control is performed by an NC device, but it is also possible to output the coordinate values read every time to a printer or the like and leave the analysis to humans. Similarly, the coordinate value signal may be sent to another computer via a communication line such as R3-232C, and the signal may be analyzed by the other computer.

Furthermore, in the above embodiment, one feed amount is stored for one machining electrical condition, but the electrode area.

Depending on the type of material etc. of the workpiece, one machining electrical condition may be stored as a plurality of feed amounts.

〔Effect of the invention〕

As described above, according to the present invention, since the NC device measures the feed amount for the machining electrical conditions and stores it,
This has the advantage that basic data for optimal processing can be easily collected and the data can be used immediately.

[Brief explanation of drawings]

Fig. 1 is a flowchart for explaining the operation of an electric discharge machining apparatus according to an embodiment of the present invention, Fig. 2 is a configuration diagram of a conventional electric discharge machining apparatus, and Fig. 3 is a basic data table showing machining conditions, etc. 4
The figure is an explanatory diagram showing the machining state of optimum machining, and FIG. 5 is a characteristic diagram showing the progress of machining. In the figure, (1) is the processing table, (2) is the X-axis motor, (
3) is a Y-axis motor, (4) is an electrode, (5) is a Z-axis motor, (6) is an NC device, (7) is a workpiece, and (8) is a processing power source. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (3)

[Claims] (1) In an electrical discharge machining device that includes a numerical control device and processes by applying a voltage between an electrode that moves in the Z-axis direction and a workpiece placed on a processing table that moves in the X and Y directions. An electric discharge machining apparatus characterized in that the positions of the X, Y, and Z axes are read and stored at fixed time intervals, machining electrical conditions are stored, and both stored contents are outputted to the outside. (2) A patent claim characterized in that the magnitude of the change in the position of the three axes and a certain set value is determined from the contents of the storage device, and the relationship between the machining electrical conditions and the machining feed amount is re-stored in a saturated state. The electrical discharge machining apparatus according to item 1. (3) In the electric discharge machining apparatus according to claim 2, a plurality of machining feed rate relationships are stored for one machining electrical condition depending on the electrode area, material of the workpiece, etc. Characteristic electrical discharge machining equipment.