JPH052836U - Electric discharge machine - Google Patents

Abstract

(57) [Abstract] [Purpose] Dust in the atmosphere on the reference position detection means installed on the side of the workpiece, which is the basis for knowing the relative position to the workpiece in the electrical discharge machine, generated during processing Oily smoke
Accurate position correction is detected and high precision machining is possible by avoiding the adhesion of machining fluid and sludge. A cover for covering the reference position detecting means installed on the side of the workpiece has magnetism, and an electrode exchanging device automatically attaches and detaches a lid from the spindle side to the reference position detecting means to hold an accurate position.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electric discharge machining apparatus that performs machining positioning based on a first reference position detecting means.

[0002]

[Prior Art]

 FIG. 3 is an overall configuration diagram showing a conventional electric discharge machine. In FIG. 3, 1 is an electrode for electric discharge machining, 2 is a workpiece to be machined, 3 is a machining tank, and 4 is a machining fluid such as insulating oil stored in the machining tank 3. Usually, each type of machining by this type of electric discharge machining device is performed by immersing the workpiece 2 in the machining fluid 4 in the machining tank 3. 5 is a pulse current generator that supplies a pulse current for electric discharge to the electrode 1 and the work piece 2, 8a is a ball screw for moving the main axis of the electric discharge machine in the vertical direction (Z-axis direction), and 8c is the work piece 2 A ball screw that moves in the left-right direction (X-axis direction), a servomotor that drives the ball screw 8a in the Z-axis direction, and a ball screw (9b) that moves the workpiece 2 in the front-back direction (Y-axis direction) orthogonal to the paper surface. Servo motor for driving (not shown), 9c for numerically controlling the drive of each servomotor 9a, 9b, 9c according to the machining program, for servomotor 10 for rotationally driving ball screw 8c in the X-axis direction. It is a device. 11 is a head located above the discharge machine, 12 is a column that is a frame material that fixes and supports the head 11, 13 is a bed that is the base of the electric discharge machine, and 14b is the workpiece 2 A moving table that moves in the front-rear direction (Y-axis direction) together with the tank 3, a moving table 14c that moves the workpiece 2 together with the processing tank 3 in the left-right direction (X-axis direction), and 15 a head that is the main axis of the electric discharge machine. Reference numeral 16 designates an electrode exchanging device for exchanging the electrode 1 mounted on the spindle, 17 an arm for grasping the electrode 1 or the like during the electrode exchanging operation, and 18 a magazine rack for accommodating various tools such as the electrode 1 or the like. ..

The conventional electric discharge machining apparatus is configured as described above, and uses the electrode 1 to perform electric discharge machining on the workpiece 2. Next, the operation of this conventional electric discharge machine will be described. Both the electrode 1 and the workpiece 2 are made to face each other while being immersed in the machining liquid 4 in the machining tank 3, and a pulse current is applied from the pulse current generator 5 to the electrode 1 and the workpiece 2. By this energization, intermittent electric discharge occurs in the machining gap between the electrode 1 and the workpiece 2, and the workpiece 2 performs machining by the electrical discharge. At this time, since the electrode 1 is connected to the Z-axis servomotor 9a by the ball screw 8a, it moves up and down in response to a command from the numerical controller 10. A Y-axis servomotor 9b is connected to the Y-axis moving table 14b via a ball screw (not shown). Each of these moving tables 14b and 14c can be moved back and forth and left and right as appropriate according to a command from the numerical controller 10. As a result, relative displacement in the horizontal direction between the electrode 1 and the workpiece 2 can be arbitrarily changed by positioning in the horizontal direction, processing in the horizontal direction, or the like. As a result, by appropriately controlling the driving of the servo motors 9a, 9b, 9c, it is possible to perform the electric discharge machining in any shape on the workpiece 2 at any position.

When performing electrical discharge machining with the above configuration, the column 12 of the electrical discharge machine, the moving tables 14b, 14c, etc. are deformed by the temperature change of the outside air and the temperature of the machining fluid 4, and the electrodes mounted on the spindle side are used. An error occurs in the relative position of the work piece. On the other hand, conventionally, a method as shown in FIG. 4 has been adopted as a thermal displacement amount correcting means which is one of means for automatically correcting this error. That is, as shown in FIG. 4, a reference position detecting means 20 is provided in the processing tank 3 in addition to the workpiece 2, and the electrode 1 is replaced with the reference electrode 21 by the electrode exchanging device 16 so that the workpiece 2 can be processed in advance. The relative position with respect to the reference position detecting means 20 is measured and stored. Then, the electrode 1 is replaced with the reference electrode 21 by the electrode exchanging device 16 at an appropriate time during processing, and the reference electrode 21 is moved to just above the reference position detecting means 20 using the stored relative position to make contact. Position the center of the column by sensing and measure each position in the X, Y and Z directions. At this time, the relative position error of the electrode and the workpiece due to mechanical deformation of the column or the like is corrected by the operation principle described below. This column center position determination is as shown in FIG. After the measurement, the reference position detecting means 20 is contact-sensed in the left-right direction X and the front-rear direction Y to detect the center of each of them and move to that position to perform positioning.

Next, these operation principles will be described. Even if the apparatus is deformed due to temperature change during processing, the relative position between the reference position detection means 20 and the workpiece 2 does not change due to temperature change. Therefore, the relative position of both before machining and the relative position during machining are the same. However, the relative position of the electrode 1 with respect to the workpiece 2 changes due to the temperature change of the table or column of the apparatus. Therefore, the position of the reference position detecting means 20 is inspected at an appropriate time, and the position is used as a reference to move to the work piece 2 at a predetermined distance and perform processing again, so that an accurate position can be processed. Of.

[0006]

[Problems to be solved by the device]

 The conventional electric discharge machine is configured as described above, and the electric discharge machining is often performed continuously for a long time. Therefore, the reference position detecting means 20 installed on the side of the workpiece in the machining tank is used. Dust in the atmosphere, oil slicks generated during processing, oil film, processing liquid, sludge, etc. may adhere. This is the size of the electric discharge machine which requires a high accuracy by causing an error in the relative position between the reference position detecting means 20 installed on the side of the work piece in the machining tank detected by the reference electrode 21 and the work piece 2. There were some problems, such as a large obstacle to accuracy.

The present invention has been made to solve the above-mentioned problems. The reference position detecting means 20 is attached with dust in the atmosphere, oil film, working liquid, sludge, etc. due to oil smoke generated during processing. The object of the present invention is to provide an electric discharge machining device capable of detecting accurate position correction without any error.

[0008]

[Means for Solving the Problems]

 The electric discharge machining apparatus according to the present invention has a means that the cover for covering the reference position detecting means 20 installed on the side of the workpiece has magnetism so that the lid can be automatically attached and detached.

[0009]

[Action]

 The electric discharge machining device according to the present invention is capable of detecting accurate position correction without depositing dust film in the atmosphere, oil film, machining liquid, sludge, etc. due to oil smoke generated during machining on the reference position detection means 20 and highly accurate electric discharge machining. Is done.

[0010]

【Example】

 Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1 and FIG. Reference numeral 20 is a reference position detecting means, 21 is a reference electrode, 22 is a cover that has a magnetism and covers the reference position detecting means 20, and 23 is an adhesion of an oil film, a processing liquid, sludge, etc. due to dust in the atmosphere and oil smoke generated during processing. A lid 24 for preventing this is a magnetic control circuit.

In FIG. 1, a reference position detecting means 20 installed on the workpiece side and a cover 22 having magnetism and covering the reference position detecting means 20 are arbitrarily installed on a table, and a reference electrode 21 is provided before processing. The relative position between the reference position detecting means 20 installed on the side of the workpiece and the workpiece 2 is measured and stored in the X, Y, and Z directions by using the above-described column center positioning method. Next, the electrode exchange device 16 is used to replace the reference electrode 21 and the lid 23 to prevent the adhesion of machining fluid, sludge, etc., and automatically move it to the upper part of the reference position detection means 20 installed on the workpiece side. After that, when a command is sent from the numerical controller 10 to the magnetic control circuit 24, magnetism is generated in the cover 22 that covers the reference position detecting means 20, and the cover 23 and the cover 22 are installed on the workpiece side when they come into contact with each other. The reference position detecting means 20 is hermetically sealed to remove dust in the atmosphere, oil film, working fluid, sludge, etc. due to oil smoke generated during processing, and the lid 23 is separated from the main shaft by the main shaft unclamping to process the workpiece. The reference position means 20 installed on the object side is in a completely sealed state.

From the above, it is possible to perform machining without having to consider the relationship between the height of the reference position detecting means 20 installed on the side of the workpiece and the machining liquid 4.

In the above embodiment, the replacement by the electrode replacement device 16 was shown, but any device that can serve as a replacement means may be used.

[0014]

[Effect of the device]

 The electrical discharge machining device according to the present invention is a basic position for detecting the relative position with respect to the work piece, which is the basis for knowing the relative position to the work piece. By generating and causing the electrode exchange device to automatically cover and remove the lid, it is possible to eliminate positioning errors by eliminating dust in the atmosphere, oil film, machining fluid, sludge, etc. due to oil smoke generated during machining. The effect is that a highly accurate discharge processing device can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a position correction function according to an embodiment of the present invention.

FIG. 2 is a view showing a main part according to an embodiment of the present invention.

FIG. 3 is a configuration diagram showing a conventional electric discharge machine.

FIG. 4 is a layout view of positioning means.

5 is an explanatory view of the positioning means shown in FIG.

[Explanation of symbols]

 2 Workpiece 3 Processing tank 4 Processing liquid 6 Mounting surface plate 7 Slider

Claims (1)

[Claims for utility model registration] [Claim 1] A workpiece is machined by passing a pulse current through a machining liquid into a machining gap where the electrode mounted on the spindle side and the workpiece are opposed to each other. In an electric discharge machining apparatus, a machining tank for filling the machining fluid, and a first reference position detecting means for installing in the machining tank and measuring a change in relative position between the electrode and the workpiece. A reference electrode replaceable with the electrode mounted on the spindle side, and a cover configured to cover the first reference position detecting means and detachable by using magnetism, EDM equipment.