JP2688128B2 - 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 machine such as a wire or a die carving for machining by generating an electric discharge between an electrode and a workpiece, and in particular, an electric discharge machine capable of easily converting machining conditions in the electric discharge machine. It relates to the device.

[0002]

2. Description of the Related Art When performing wire electric discharge machining, it is necessary to set machining conditions in advance, and generally, the machining conditions are determined by referring to a machining condition table.

The above-mentioned machining condition table is categorized by the workpiece (type of material), the wire diameter, the thickness of the workpiece, etc., and for each of them, a condition in which wire breakage is less likely to occur step by step from the maximum machining condition. It is divided into 3 to 5 stages so as to shift to. In addition, other conditions such as taper processing and step processing are described.

Regarding the work (material type), SKD
-11, WC-Co, copper, graphite and the like. Wire diameters are φ0.1, φ0.15, φ0.2, φ
0.25, φ0.3, etc. There are 5 mm, 10 mm, 20 mm, 30 mm ... About the thickness of the workpiece.

Further, there are a plurality of processing condition patterns from one-time processing to two, three, four ... The table shown in FIG. 12 is an example of a processing condition table in the case of only one processing. The table shown in FIG. 13 is an example of a processing condition table when finishing is performed. Each of these processing conditions is numbered and stored in the numerical controller as a processing condition pack.

Next, processing conditions will be described. There are, for example, the following eight types of processing conditions. Vo (voltage switching): Switch for selecting the height of the inter-electrode voltage under no load Ip (Processing setting): Switch for selecting the magnitude of the peak current flowing between the electrodes OFF (pause time): Discharge Switch for selecting the time from the end of application until voltage is applied again WS (Wire speed): Switch for adjusting the wire feed speed WT (Wire tension): Wire tension (Wire tension)
Switch for adjusting LQ (working liquid flow rate): Switch for adjusting working liquid amount LR (Working liquid specific resistance): Switch for adjusting working liquid specific resistance VC (Average working voltage): Optimal feed Switch for setting the average machining voltage that is the target value for machining

FIG. 9 shows a schematic structure of a conventional wire electric discharge machine, 1 is a wire electrode, 2 is a workpiece, 3 is a selection circuit, 4 is a switching circuit (finishing circuit), 5 is a resistor, and 6 Is an automatic voltage regulator, 7 is a control circuit, a transmission circuit,
A logic circuit 8 is a processing condition setting circuit.

Next, the operation will be described. This wire electric discharge machining apparatus applies a voltage between the wire electrode 1 and the workpiece 2 to generate a discharge pulse by high-speed switching of the power transistor in the selection circuit 3 for machining.

FIG. 10 shows a specific structure of the machining condition setting circuit 8 shown in FIG. 9, and in the figure, 11 is a memory for storing a basic standard machining condition pack,
Reference numeral 12 is a processing condition call selection means for calling or selecting the optimum processing conditions from the memory 11, 13 is a memory for temporarily storing the processing conditions called or selected by the processing condition call selection means 12, and 17 is a memory 13. It is a processing means for performing processing under the processing conditions temporarily stored in.

In the memory 11, the wire electrode material /
Machining condition data for each diameter, workpiece type / plate thickness and finished surface roughness is stored. Further, there are several methods for calling or selecting the optimum condition from the memory 11 by the processing condition call selecting means 12. For example, the first method is a manual method. This is a method in which the operator sets the processing condition pack number on the screen of the control device and calls the processing conditions. However, since this method cannot call a plurality of processing conditions at the same time, the following second and third methods are used in the case of processing that requires automatic switching of the processing conditions.

A second means is a method of setting a machining condition pack in the NC program and calling the machining condition accordingly. The third means is a method of using the automatic second cut function. This function automatically selects and calls the conditions for the second cut (offset, processing condition pack number, set processing speed) by inputting the parameters required for the processing from the automatic second cut dedicated screen. Processing is performed depending on the conditions.

Next, the operation will be described. FIG. 11 is a flowchart showing processing condition setting in the conventional apparatus. First, the workpiece / machining shape is determined (step 1), and then the machining accuracy / surface roughness is determined (step 2). After that, the wire electrode is selected based on the thickness of the workpiece and the instruction of the minimum corner radius (step 3), and further the jig is selected based on the workpiece, the machining shape and the like (step 4). After that, it is judged from the processing accuracy and surface roughness whether or not the second cut is necessary (step 5), and when the second cut is necessary, the second cut processing condition is selected (step 6). On the contrary, if it is not necessary, the maximum speed condition is selected (step 7).

Thereafter, the processing conditions selected in step 6 or step 7 are set (step 8),
Further, it is judged whether or not it is necessary to change the processing conditions according to the unstable factor (step processing, taper processing, etc.) (step 9). When it is necessary to change the machining conditions according to the instability factor, the machining condition for the instability factor is referred to (step 10). Next, the processing conditions are corrected based on the information of the referenced processing conditions (step 11). To modify the processing conditions, the numerical control device calls the screen of the processing condition pack, and on this screen, necessary data is edited out of the 15 types of data constituting the processing conditions.

After that, or when it is unnecessary to change the processing conditions according to the unstable factor, the processing is started (step 12). After that, it is judged whether or not the machining state is stable (step 13), and if wire breakage or the like is likely to occur and the machining state is not stable, the process returns to step 11 again to correct the machining conditions. This operation is repeated until the processing state becomes stable.

[0015]

Since the conventional wire electric discharge machining apparatus is constructed as described above, the operator manually performs machining when economical machining or stable machining in which wire breakage does not occur is desired. Since it is necessary to correct the content of the condition, there is a problem that the operation takes time and hinders quick work. Further, there is a problem that it is difficult to secure an operator because the technique and experience for performing the above operation are required.

The present invention has been made in order to solve the above-mentioned problems, and realizes rapid work by easily converting the contents of processing conditions, and economical processing or wire breakage does not occur. An object of the present invention is to obtain an electric discharge machining device that can easily perform stable machining.

[0017]

DISCLOSURE OF THE INVENTION The electric discharge machining apparatus according to the present invention is a first electric discharge machining apparatus for storing a preparatory machining condition pack which is a basic in an electric discharge machining apparatus for machining by generating an electric discharge between an electrode and a workpiece. Storage means, processing condition call selection means for calling or selecting an optimum condition from the first storage means, and second storage means for temporarily storing the processing condition called or selected by the processing condition call selection means. , Third storage means for storing a program for converting the processing conditions, and anxiety about step processing, taper processing, etc.
If it is necessary to change the processing conditions according to constant factors, add any
Input a signal to change the machining conditions to the desired machining conditions.
And a processing condition stored in the third storage means, the processing condition being temporarily stored in the second storage means in accordance with a signal from the input means for controlling the processing condition conversion function. An arithmetic means for performing conversion by a conversion program is provided, and machining processing is executed based on the machining conditions converted by the arithmetic means.

Further, the input means is constituted as a machining speed volume, a wire breakage prevention volume or an economical operation volume.

[0019]

When the machining condition conversion switch or volume is operated during machining, the machining condition conversion program is called, and the machining conditions temporarily stored by being called from the machining condition pack are converted according to this program. Be done. Then, the processing is performed based on the processing conditions after the conversion.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 21 is a memory for storing a basic standard processing condition pack, 22 is a processing condition calling selection means for calling or selecting an optimum processing condition from the memory 21, and 23 is a processing condition calling selection means 22. The memory for temporarily storing the machining conditions called or selected by 24, the memory for storing the program for converting the machining conditions, the reference numeral 25 for the switch or the volume for the conversion of the machining conditions, and the reference numeral 26 for the switch or the above. An arithmetic unit for converting the machining conditions temporarily stored in the memory 23 by the machining condition conversion program of the memory 24 in accordance with the signal from the volume 25, and 27 performs machining based on the machining conditions converted by the arithmetic unit 26. It is a processing means for performing.

Next, the operation will be described. 2, steps 1 to 9 and steps 12 to 13 are the same as the operation of the conventional technique shown in FIG. The different part of the invention is step 10. If it is determined in step 9 that the machining conditions need to be changed according to the unstable factor, the process proceeds to step 10 to adjust the machining condition conversion switch or volume. The processing conditions are automatically corrected by the operation of step 10.

It is easy to use a plurality of switches or volumes for converting the processing conditions. For example,
A volume for machining speed, a wire breakage prevention volume or a volume for economical operation can be considered. The processing speed volume controls the processing speed and controls the processing time. The wire breakage prevention volume is used when wire breakage is likely to occur, and thus wire breakage can be easily prevented. Moreover, the economic operation for Boryuumu is intended to reduce the consumption of the wire electrode by controlling the wire feed speed.

For the conversion of the processing conditions, for example, the setting items of the processing conditions are Vo-Ip-OFF-SA-SB -...
-There is a plurality of types, such as the above, by constructing a conversion program for converting the processing conditions according to predetermined conditions.

A processing condition conversion program for preventing the occurrence of wire breakage will be taken as an example. The table shown in FIG. 8 shows the conditions for the conversion. 1 for switching
Suppose there is a 0-level volume. Here, the volume 0 is a standard processing condition, and the processing condition is not converted. The volumes 1 to 9 convert the processing conditions, and the larger the value, the less likely the wire breakage occurs.

Although a typical example has been described here, a plurality of conversion programs may be considered in addition to these. For example, based on standard machining, run-up machining,
It is also possible to convert into processing conditions of step processing and taper processing. Fig. 3 (optimum state), Fig. 4 (running machining), Fig. 5
(Step processing), FIG. 6 (Step processing using a jig), FIG.
(Taper processing) is an example of condition conversion for each processing classification. Here, workpiece SKD-11, wire electrode brass system φ
An example in which the processing conditions have been changed is shown taking the case of 0.2 and the plate thickness of 40 mm as an example. The data in the thick frame is different from the standard condition (optimal state). If a machining condition conversion program is created according to these patterns, all machining can be performed in a stable state.

[0026]

As described above, according to the present invention, since the contents of the processing conditions can be easily converted by the switch, the volume, etc., the quick work can be realized and the economical processing or the wire breakage can be realized. Stable processing that does not occur can be easily performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a processing condition setting circuit according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of a processing condition setting circuit shown in FIG.

FIG. 3 is an explanatory diagram showing an example (optimal state) of condition conversion for each machining classification according to the present invention.

FIG. 4 is an explanatory view showing an example (running machining) of condition conversion for each machining classification according to the present invention.

FIG. 5 is an explanatory view showing an example (step processing) of condition conversion for each processing classification according to the present invention.

FIG. 6 is an explanatory diagram showing an example of condition conversion for each machining classification (step machining using a jig) according to the present invention.

FIG. 7 is an explanatory diagram showing an example (taper machining) of condition conversion for each machining classification according to the present invention.

FIG. 8 is a table showing a processing condition conversion program example for preventing the occurrence of wire breakage according to the present invention.

FIG. 9 is an explanatory diagram showing a configuration of a conventional wire electric discharge machine.

FIG. 10 is a block diagram showing a configuration of a conventional processing condition setting circuit.

11 is a flowchart showing an operation of the processing condition setting circuit shown in FIG.

FIG. 12 is an example of a conventional processing condition table in the case of only one-time processing.

FIG. 13 is an example of a processing condition table when performing conventional finishing processing.

[Explanation of symbols]

21 Memory for storing machining condition pack 22 Machining condition call selection means 23 Memory for temporarily storing machining condition 24 Memory for storing machining condition conversion program 25 Machining condition conversion switch or volume 26 Machining Arithmetic unit for converting conditions 27 Processing means

Claims (2)

(57) [Claims] 1. A discharge machining apparatus for machining by generating electric discharge between electrodes between workpiece, a first storage means for storing the prepared processing conditions pack underlying this, before Symbol first storage means to perform the machining condition calling selection means for calling or select the optimal conditions, a second storage means for temporarily storing call or selected processing conditions by pre-Symbol machining condition calling selecting means, the conversion of the pre-Symbol processing conditions Storage means for storing the program of No. 3, and machining conditions according to unstable factors such as step machining and taper machining
If you need to change
If the input signal to change to, the input means for controlling the conversion function of the processing conditions, the entering the said in accordance with a signal from the force means a second machining condition temporarily stored in the storage means 3 discharge machining apparatus of a calculating means by stored by that processing conditions conversion program for converting the storage means, and executes the processing based on the converted processing conditions by pre-Symbol calculating means. 2. The electric discharge machining apparatus according to claim 1, wherein the input means is configured as a machining speed volume, a wire breakage prevention volume, or an economical operation volume.