JPH0724170Y2 - Electrode guide for small hole electric discharge machine - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an electrode guide for a small hole electric discharge machine.

[0002]

2. Description of the Related Art A small-hole electric discharge machine is a type of die-sinking electric discharge machine, which repeats pulse discharge between the tip of a thin rod-shaped electrode and a workpiece to make a small hole in the workpiece. Since the rod-shaped electrode maintains the roundness accuracy of the machined hole, it is usually 3
Since it is rotating inside and outside of 00 rotations and its diameter is smaller than its length, its lower portion is guided by an electrode guide in order to maintain the positional accuracy of the processed hole. This electrode guide is generally made of a hard material such as stainless steel or ceramics,
It is formed in a pipe shape or by a combination of a V groove and a flat plate.

Further, when the processing of one hole is finished and the processing of the next hole is started, the electrode must be surely detached from the workpiece, so that the electrode is sufficiently raised. As the existing raising method, the main shaft (quill) holding the electrode is raised to the upper limit or a limit switch provided separately,
There are methods such as raising the spindle to the machining start position.

[0004]

As described above, the small hole electric discharge machine is provided with an electrode guide for guiding the lower part of the rod-shaped electrode. When the electrode is lifted up, the electrode guide is grabbed by the electrode guide. Therefore, the electrode guide needs to be larger than the diameter of the rod-shaped electrode by a predetermined dimension (for example, about 0.04 mm) or more. There was a problem that the accuracy was lowered.

In addition, the conventional raising method in the case of moving the electrode requires an auxiliary guide for re-insertion because the rod-shaped electrode comes out of the electrode guide in addition to unnecessary loss of moving time. The present invention was made in view of such a problem, and its first object is to provide an electrode guide that improves the accuracy of the position and hole diameter of the processed hole, and the loss of the moving time of the electrode is reduced. A second object is to provide electrode guides that are few and do not require auxiliary guides.

[0006]

In order to achieve the above-mentioned first object, the electrode guide of the present invention has an electrode passage hole of a rod-shaped electrode which moves vertically along the center line of the body of the electrode guide. The upper guide member made of a hard material is provided on the upper part of the electrode passage hole, the lower guide member made of a hard material is provided on the lower part of the electrode passage hole, and the lower electrode of the lower guide member is attached to the rod-shaped electrode. It is provided with a cutting blade for removing dust.

In order to achieve the second object, the electrode guide of the present invention detects the tip position of the rod-shaped electrode at the time of movement of the electrode in the central portion of the body of the electrode guide in the direction perpendicular to the electrode passage hole of the rod-shaped electrode. An electrode detection hole is provided. Here, the movement of the electrode means the movement of the electrode when one hole is processed and the next hole is processed.

[0008]

With this structure, the machining chips adhering to the rod-shaped electrode during the machining of the fine holes are guided by the electrode guide when the rod-shaped electrode (which rotates inside and outside 300 revolutions per minute as described above) rises. It is scraped off by the cutting blade provided on the lower guide member of. Therefore, the gap between the rod-shaped electrode and the electrode guide can be made smaller than before.

Further, when the rod-shaped electrode rises, when the lower end of the rod-shaped electrode passes through the electrode detection hole provided in the central portion of the electrode guide, it is detected by an optical sensor device or the like. You can limit it.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a schematic explanatory view of a small hole electric discharge machine embodying the present invention. Spindle 1 (quill) as shown
Is vertically movably provided along the vertical member 3 by a servomotor and a ball screw 7 placed on the upper portion thereof, and a rod-shaped electrode 11 is attached to the lower portion thereof via a chuck 9. An electrode guide 13 is attached to the lower portion of the vertical member 3, and an optical sensor device 15 for detecting the tip position of the rod-shaped electrode 11 is attached near the center of the vertical member 3 when the rod-shaped electrode 11 rises.

The vertical member 3 is vertically movable by a ratchet wheel, a rack mechanism 17 and an electrode guide positioning motor 19.

The work piece 21 is freely moved in the X and Y axis directions by the X axis motor 23 and the Y axis motor 25.
It is fixed inside the processing tank 29 placed on the No. 7. The machining liquid is supplied from the machining liquid supply device 31 to the machining tank 29 by the pump 33, and when the rod-shaped electrode is hollow, is supplied to the rod-shaped electrode 11 via the main shaft (quill) 1. Also,
A pulse voltage is applied to the rod-shaped electrode 11 and the workpiece 21 from a machining power source 35. The servo motor 5, the optical sensor device 15, the electrode guide positioning motor 19, the X-axis motor 23, the Y-axis motor 25, the pump 33 and the like are NC devices 37.
Controlled by.

Details of the electrode guide 13 are shown in FIGS. 1 (A) and 1 (B). The main body 13-1 of the electrode guide 13 is made of stainless steel, brass or the like, has a columnar shape with the upper and lower corners being conical, and the electrode passage hole 13-2 is provided along the centerline of the column. . Electrode passage hole 13-
On the upper part of 2, the upper guide member 13 made of ceramics
-3 is attached, and the hole diameter is about 0.02 mm (1/2 of the conventional diameter) larger than the diameter of the rod-shaped electrode.
A lower guide member 13-4 made of sapphire (may be diamond) is attached to the lower portion of the electrode passage hole 13-2, and a V-shaped or semicircular groove 13-5 forming a cutting blade is formed at the lower end thereof. It is provided. Lower guide member 13-
The hole diameter of No. 4 is the same as the hole diameter of the upper guide member 13-3.
Further, an electrode detection hole 13-6 for detecting the tip position of the rod-shaped electrode is provided in the center of the main body.

FIG. 2 shows a mounting portion of the electrode guide 13. As shown in the figure, the electrode guide 13 is provided with a disc-shaped electrode holder 39 having a protrusion at its center and a pressing member 39-1.
It has been fixed accurately. A sensor through hole 39-2 is provided in the center of the holder 39 in the diametrical direction.
The central axis of the sensor through hole 39-2 and the central axis of the detection hole 13-6 of the electrode guide 13 are substantially coincident with each other. Also,
An optical sensor device 15 (for example, a semiconductor laser and an optical sensor) that detects the position of the tip of the rod-shaped electrode is provided at both ends of the sensor through hole 39-2. This electrode holder 39
Is fixed to the lower part of the vertical member 3, and as described above,
The electrode guide positioning motor 19 allows the vertical position to be freely adjusted.

With this structure, when the rod-shaped electrode 11 is raised while being rotated, the machining waste attached to the lower portion of the rod-shaped electrode 11 is provided in the lower guide member 13-4 of the electrode guide 13 (cutting blade). It is scraped off by 13-5. Therefore, the rod-shaped electrode can be easily raised. Also,
The lower tip position of the rod-shaped electrode 11 during the rising is reliably detected by the optical sensor device 15 through the electrode detection hole 13-6.

[0016]

As can be understood from the above description, since the present invention has the structure described in the scope of claims for utility model registration, the gap between the rod-shaped electrode and the electrode guide can be made much smaller than before. Therefore, the precision of the position and hole diameter of the processed hole can be significantly improved. In addition, the loss of the moving time of the rod-shaped electrode is reduced, and the auxiliary guide is unnecessary.

[Brief description of drawings]

FIG. 1A is a front sectional view of an embodiment of an electrode guide of the present invention. The figure (B) is also a bottom view.

FIG. 2 is a front sectional view of a mounting portion of the electrode guide of the present invention.

FIG. 3 is a schematic explanatory view of a pore electric discharge machine equipped with an electrode guide of the present invention.

[Explanation of symbols]

 11 bar-shaped electrode 13 electrode guide 13-1 main body 13-2 electrode passage hole 13-3 upper guide member 13-4 lower guide member 13-5 groove 13-6 electrode detection hole 15 optical sensor device 39 electrode holder

Claims (2)

[Scope of utility model registration request] 1. An electrode passage hole of a rod-shaped electrode that moves in a vertical direction is provided along a center line of a body of the electrode guide, and an upper guide member made of a hard material is provided above the electrode passage hole.
A lower guide member made of a hard material is provided in the lower part of the electrode passage hole, and a cutting edge for removing machining scraps adhering to the rod-shaped electrode is provided in the lower end part of the lower guide member. Electrode guide. 2. A small hole electric discharge machine according to claim 1, wherein an electrode detection hole for detecting the tip position of the rod-shaped electrode is provided in the center of the body of the electrode guide in a direction perpendicular to the electrode passage hole. Electrode guide.