JPS5932253B2 - Electric discharge machining equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric discharge machining apparatus, and more specifically, to a position where the relative position between a machining electrode and a workpiece immersed in a machining fluid can be easily detected. The present invention relates to an electrical discharge machining device equipped with a drawing jig.

Generally, in electrical discharge machining equipment, machining is performed with the workpiece immersed in the machining fluid, so the machining fluid (e.g. oil) and machining debris mix. covered with a tar-like substance that is a mixture of Therefore, in order to process the workpiece to the required dimensions, the predetermined reference plane determined on the workpiece is the same as that of the workpiece once it has been immersed in the machining liquid. Unless the machining fluid mixed with machining debris is wiped off, it cannot be used as a reference surface for determining machining dimensions. By the way, for example, when a workpiece is machined unmanned and automatically by combining an electrical discharge machining device with an automatic electrode exchange device, it is necessary to bring the replaced machining electrode into contact with a predetermined reference surface of the workpiece. ), the relative positional relationship between the replaced machining electrode and the workpiece is detected.
In such cases, the reference plane of the workpiece cannot be used for the reasons mentioned above. Therefore, conventionally, when using an automatic electrode exchange device, for each processing electrode to be used, the length of the electrode and the grinding distance from the center are measured in advance and the values are calculated. By manually inputting these data into the control device, the relative positional relationship between the machine and the workpiece can be grasped and desired processing can be performed. However, it is time-consuming and extremely inefficient to measure each of the processing electrodes used and input this data into a numerical control device. Therefore, an object of the present invention is to accurately know the relative positional relationship between any machining electrode and the workpiece even when the workpiece, especially its reference surface, is contaminated by machining fluid. An object of the present invention is to provide an electric discharge machining apparatus that can perform the following operations.

Hereinafter, V) the present invention will be explained in detail with reference to the illustrated embodiments.

FIG. 1 shows a perspective view of the main parts of an electric discharge machining apparatus according to the present invention.

The symbol 1 is a processing tank, and this processing tank is equipped with a moving table (
(not shown), and is positioned at a desired relative position with respect to the processing electrode 2 together with a moving table by a drive motor (not shown). The processing electrode 2 is a quill 3
9, which is removably attached to the. The processing electrode 2 is replaced without manual intervention by an automatic electrode replacement device (not shown). A machining fluid 4 is poured into the machining tank 1, and a workpiece 5 is immersed in the machining fluid 4. The workpiece 5 is a workpiece 5 in the direction of the arrow X.
and a reference surface b that provides the origin of the relative position between the workpiece 5 and the processing electrode 2 in the direction of the arrow Y. In order to be able to provide a reference position to the machining electrode 2 even if these reference surfaces A and b are contaminated by machining fluid and machining debris,
The electrical discharge machining apparatus of the present invention includes two position detecting tools 6 and 7. The position detection tool 6 has a main body 6a made of a substantially U-shaped prismatic member, and processing electrode abutting parts 6b and 6c with which the processing electrode 2 is brought into contact are formed at both ends of the main body 6a. There is.

The shape of these processing electrode contact portions 6b6c is in the shape of a cutting edge, and the cutting edge portions 6d and 6e of each contact portion 6b6c are formed to face each other. This position detecting tool 6 detects a reference position 9 in the moving direction indicated by arrow It is attached to the bottom of the processing tank 1 so that it is parallel to the direction. In this attached state, each processing electrode contact portion 6b
, 6c protrude from the upper surface of the machining fluid 4.
It is an important feature of the present invention that these contact portions protrude above the upper surface of the machining fluid 4. The other position detecting tool 7 also has the same shape as the above-described position detecting tool 6, with the only difference being that the arrangement direction V1 is parallel to the Y direction.

Therefore, in FIG. 1, the parts corresponding to the position detecting tool 6 are designated by reference numerals having the same suffix as the reference numeral 7, and the explanation thereof will be omitted. As shown in FIG. 2, these position detection tools 6 and 7 are positioned in a predetermined relationship with each reference plane A and b of the workpiece 5. That is, the center position P of the position detector 6 is set at a distance of L1 from the reference plane a in the X direction. On the other hand, the center position Q of the position detector 7 is at the reference plane b
The distance is defined as L2 from the point in the Y direction. Here, the center position of the position detector is the midpoint of a line segment connecting the cutting edges of a pair of opposing machining electrode abutting portions in each position detector, that is, the portions that the machining electrodes actually abut. In this way, when the position detectors 6 and 7 are installed in the machining tank, even if the reference surfaces A and b become unavailable due to contamination of the machining fluid, the machining electrode contact parts 6b, 6c, 7b, 7c can be used to position the processing electrode 2 in a desired relative positional relationship with the workpiece 5. Hereinafter, a case will be described in which a position detection tool is used to position a processing electrode.

First, the processing electrode 2 is positioned at an arbitrary position on the line connecting the cutting edge portions 6d and 6e.

After that, the machining electrode 2 is moved in one direction along the X direction until the machining electrode 2 comes into contact with the cutting edge part 6d, and then moved in the other direction, so that the machining electrode 2 is brought into contact with the cutting edge part 6e. Move it until it touches. At this time, a numerical control device (not shown) measures the distance l that the application electrode 2 has moved from the time it leaves the blade edge 6d until it contacts the blade edge 6e. This distance l is a1+A in FIG.
2, the center of the processing electrode 2 can be made to coincide with the midpoint P by further moving the processing electrode 2 by 1/2 in one direction along the X direction. Since the relationship between the midpoint P and the reference plane a has already been determined as a predetermined relationship, if the machining electrode 2 is further moved by L1 toward the left in FIG. The center of and the reference plane a coincide. Therefore, the scale within the numerical control device can be corrected assuming that the position of the processing electrode 2 at this time is the origin in the X direction. As described above, by using the position detection tool arranged in a predetermined positional relationship with the workpiece 5, the center position of any processing electrode can be aligned with a desired reference position without having to measure it in advance. . Regarding the arrow Y direction, the position detector 7 is used to detect the Y direction in exactly the same way.
Directional positioning can be performed. Therefore, even when replacing electrodes one after another using an automatic electrode exchanger to automatically perform electric discharge machining, the dimensions of the machining electrodes can be determined without measuring each of the machining electrodes to be replaced. Even if there are variations, the center of the processing electrode can be accurately aligned with the desired reference position. For this reason, as will be readily understood, even if the workpiece 5 becomes soiled as processing progresses and its reference surface becomes unusable, it has nothing to do with the soiling of the reference surface, and Even if the dimensions of the electrode are odd, the center position of the processing electrode can be detected and the processing electrode can be set in a predetermined positional relationship with respect to the workpiece. There are various shapes of processing electrodes, but as shown in Figures 3A to 3Evc, they are always made with a center core, and this center core is aligned with the desired reference plane a. or b.

Therefore, by using the apparatus shown in FIG. 1, this center core can be easily determined. In the illustrated example, the position detector is 2
Although one is provided, depending on the case, one or three or more may be provided. As shown in Fig. 4, the shape of the circumference and the contact part of the processing electrode is such that the length D is 10 [MO or more,
It is preferable that the thickness w of the cutting edge be 1 [MO or less] because the influence of burrs on the processing electrode will be reduced. That is,
Dshi: T. 5. It is preferable to make W as long as possible, while making W as thin as possible in order to accurately know the center of the processing electrode. Further, in the above embodiment, a cutting edge shaped part was used as the machining electrode contact part, but a spherical part may be used as shown in FIG.

According to the present invention, as described above, even when the reference surface of the workpiece cannot be used as a reference surface due to contamination, it is possible to accurately provide the reference position to the processing electrode, and also Since the core can be easily indexed, there is no need to measure the electrode dimensions in advance, especially when used in combination with an automatic electrode changer, and any processing can be performed without cleaning the workpiece. The electrode can be positioned in a desired relative positional relationship with respect to the object to be subjected to force, and excellent effects such as highly accurate machining can be performed without manual intervention.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional perspective view of an embodiment of the present invention, FIG. 2 is a plan view of the embodiment shown in FIG. 1, and FIGS.
Figure e is a plan view showing various electrode shapes, Figure 4 is an enlarged view of the machining electrode abutting part shown in Figure 1, and Figure 5 is a perspective view of another embodiment of the position detector. 1... Processing tank, 2... Processing electrode, 4... Processing liquid, 5... Workpiece, 6
, 7...Position detector, 6a...Main body,
6b, 6e... Machining electrode contact part, 6d, 6e
...Blade tip, A, b...Reference surface.

Claims (1)

[Scope of Claims] 1. An electric discharge machining apparatus having a machining tank containing a machining fluid and performing electrical discharge machining by immersing a workpiece in the machining fluid in the machining tank, wherein the workpiece is At least one position detecting tool having a predetermined positional relationship with a predetermined reference plane and on which a pair of machining electrode contact parts is formed is installed so that the machining electrode contact part is lower than the surface of the machining fluid. An electric discharge machining apparatus, characterized in that it is provided in the machining tank so as to be located above, thereby providing a reference position to the machining electrode. 2. Claim 1, characterized in that the position detecting tool comprises a U-shaped main body and a cutting edge-like abutting part formed at each end of the main body so as to face each other. electrical discharge machining equipment. 3. The electric discharge machining apparatus according to claim 1, wherein the position detection tool includes a pair of spherical machining electrode contact parts. 4. The electric discharge machining apparatus according to claim 2, wherein the cutting edge-like contact portion has a length of 10 mm or more and a cutting edge thickness of 1 mm or less.