JPH09253943A - Electrical discharge machine for forming shape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the most-suitable machining conduction to be determined even if a machining electrode has a complex shape and increase an assumed degree of precision of machining time. SOLUTION: In an electrical discharge machine for firming a shape with a shape electrode 1, there is provided means 8 for measuring a height of liquid surface 7 of processing liquid 4 and then a machining area is calculated in reference to a feeding amount of the shape electrode 1 and a varying amount of height of the liquid surface 7. In addition, there is provided means 5 for parting a part of a processing tank 3 into a small region 6 and then means 8 for measuring the height of the liquid surface 7 is arranged in the small region 6. With such an arrangement as above, even if the processing electrode has a complex shape, it is possible to determine the most-suitable processing condition and also it shows an effect that an estimating precision of the processing time is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die-sinking electric discharge machine for machining a workpiece by generating an electric discharge between the workpiece and a shaped electrode.

[0002]

2. Description of the Related Art A die-sinking electric discharge machine is an apparatus for generating an electric discharge between a work piece and a shape electrode to form a shape substantially the same as that of the shape electrode on the work piece. In such an electric discharge machining, if machining is performed with an electric discharge energy which is excessive with respect to the machining area, the electrode is consumed much and the machining becomes unstable. In addition, processing with a small amount of energy reduces the processing efficiency. That is, there is an appropriate condition range for the magnitude of the discharge energy supplied per unit area, and it is necessary to select an appropriate processing condition range according to the processing area.

[0003]

Therefore, the electrode has been subdivided in the working depth direction, and the working area has been calculated by calculating on the desk. Further, the processing conditions were selected from the calculated processing area, and the processing time was calculated from the processing speed at that time. However, when the shape is complicated, it takes a lot of time for calculation. Further, when the shape is simplified and an approximate value is obtained, the optimum processing condition cannot always be selected. In addition, the accuracy of processing time estimation decreased.

The object of the present invention is to solve the above-mentioned problems in the prior art, and it is possible to determine the optimum machining conditions even for an electrode having a complicated shape, and a die-sinking discharge with which the machining time is highly accurately estimated. Providing processing machines.

[0005]

In order to achieve the above object, the present invention provides a die-sinking electric discharge machine for machining using a shape electrode, which is provided with a means for measuring the liquid level of a machining liquid. It is characterized in that the processing area is calculated from the feed amount of the shaped electrode and the change amount of the liquid level height. Also,
A means for partitioning a part of the processing tank into a small area is provided, a means for measuring the liquid level height is arranged in the small area, and a processing area calculation means and a means for setting optimum processing conditions from the obtained processing area are provided. Is provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the illustrated embodiments. FIG. 1 is an overall configuration diagram showing an embodiment of the present invention. In this figure, 1 is a shape electrode. Two
Is a feed mechanism that moves the shaped electrode 1 up and down. 3 is a processing tank. Reference numeral 4 is a working liquid, and the necessary amount is put in the working tank 3. A partition 5 partitions a part of the processing tank 3 into small areas 6.
The partition 5 is attachable to and detachable from the processing tank 3. When the partition 5 is attached to the processing tank 3, the processing liquid 4 in the small area 6
Are completely shielded from other areas. 7 is the surface of the working fluid 4. 8 is a liquid level measuring device. Reference numeral 9 denotes a numerical control device in which a database of optimum processing conditions and the like corresponding to the processing area is registered in advance. Then, the numerical control device 9 calculates not only the control of the feed mechanism 2 but also the cross-sectional area of the shape electrode 1 from the measurement value of the liquid level measuring device 8 and refers to the internal processing condition table to select the optimum processing condition. At the same time, the processing time is estimated.

Next, the operation of this embodiment will be described. First, the procedure for obtaining the processing area S will be described. The tip of the shaped electrode 1 is brought into contact with the liquid surface 7 by the feeding mechanism 2, the machining depth is input to the numerical controller 9 with the position set as a depth of 0, and the numerical controller 9 is operated. Then, the numerical control device 9 operates the feed mechanism 2 to feed the shaped electrode 1 into the machining liquid 4 while storing the measured value of the liquid level detection device 8 for each predetermined feed amount a until the machining depth is reached.

As is known as the Archimedes principle, when the shaped electrode 1 is put into the working fluid 4, the height of the liquid surface 7 rises according to the volume of the fed shaped electrode 1.
Therefore, the numerical controller 9 obtains the average cross-sectional area (that is, the average processing area) S of the shaped electrode 1 for each feed amount a by the following equation. S = hA / a (1) where h is the amount of change in the liquid level 7. A is the surface area of the processing tank 3, which is a constant specific to the processing tank 3.

Next, a procedure for the numerical controller 9 to select a machining condition and a procedure for obtaining the machining time t will be described. FIG. 2 is a processing condition diagram showing the relationship between the processing area S and the processing energy (JT: ratio of energy supplied by a processing power source (not shown)). In this figure, the range between the curve q and the curve r is the processing condition range, and the curve p is the most appropriate condition. In the region above the curve q, the shape electrode 1 is heavily consumed, and in the region below the curve r, the efficiency does not increase, and neither can be properly machined. Further, FIG. 3 is a diagram showing the relationship between the processing energy (JT) and the processing speed. And
2 and 3 are registered in the numerical controller 9 in advance.

Now, the average cross-sectional area S in the i-th section
_{If i} is 500 mm ² , the numerical controller 9
From the curve p shown in FIG.
Select T = 24. From FIG. 3, the volume processing speed v _i when the processing energy JT = 24 is 102 mm ³ / mi.
After confirming that it is n, the processing time t _i is _calculated by the following equation.

T _i = S _i a / v _i (2) Then, the total machining time is obtained as the sum of t _i , and machining is performed while changing the machining conditions for each feed amount a.

By the way, the sectional area of the shape electrode 1 is equal to that of the processing tank 3.
If the feed amount a is set to a small value when it is smaller than the surface area of, the measurement of the change amount h of the liquid surface 7 becomes difficult.
In such a case, the partition 5 is attached to the processing tank 3 and the shaped electrode 1 is fed into the small region 6. Then, since the value of the surface area A in the equation (1) becomes small, the amount of change h of the liquid surface 7 becomes relatively large, which facilitates the measurement and improves the measurement accuracy.

Although the detection value of the liquid level detection device 8 is directly input to the numerical control device 9 in the above description, the operator reads the change amount of the liquid level detection device 8 and the numerical control device 9 reads it. You may input it. The operator may also input the setting of the processing conditions.

[0014]

According to the present invention, even for a machining electrode having a complicated shape, the optimum machining conditions can be determined, and the estimation accuracy of the machining time can be improved.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram according to an embodiment of the present invention.

FIG. 2 is a processing condition diagram showing the relationship between the processing area S and the processing energy.

FIG. 3 is a diagram showing a relationship between processing energy and processing speed.

[Explanation of symbols]

 1 Shaped electrode 2 Feed mechanism 3 Processing tank 4 Processing liquid 5 Partition 6 Small area 7 Liquid level 8 Liquid level detection device 9 Numerical control device

Front page continuation (72) Inventor Tomoji Kato 2100 Kamiimaizumi, Ebina City, Kanagawa Prefecture Hitachi Seiko Co., Ltd.

Claims (3)

[Claims] 1. A die-sinking electric discharge machine for machining using a shape electrode is provided with means for measuring the liquid level of a machining liquid, and machining is performed based on the feed amount of the shape electrode and the variation in the liquid level. A die-sinking electric discharge machine characterized by calculating the area. 2. A means for partitioning a part of the processing tank into small areas,
The die-sinking electric discharge machine according to claim 1, wherein means for measuring a liquid level height is arranged in the small area. 3. The die-sinking electric discharge machine according to claim 1, further comprising a machining area calculating means and a means for setting an optimum machining condition from the obtained machining area.