JPH05261624A - Electro-discharge machining unit - Google Patents

Abstract

PURPOSE:To provide an electro-discharge machining unit that is made so as to capacitate it to machine a helical flute of a drill or the like. CONSTITUTION:An X-axis table 3 mounted with a Y-axis table 2 and a Z-axis part 4 in opposition to these elements are all set up in a base 1 of this device. The Y-axis table is provided with a spindle 6 holding a work through a chuck 9. The Z-axis part 4 is provided with a spindle 10 attached with a smoothly turnable rotating electrode 11 which is formable on a machine by means of a truing tip 7. In the case of cylindrical machining, a cupped stonelike rotating electrode 11 is applied, but in the case of grooving, an almost flat stonelike rotating electrode 11 is applied likewise. In the case of the latter, if a grinding wheel is installed concentrically with the rotating electrode 11, removal of an affected layer produced by the electro-discharge machining of the rotating electrode 11 is easily performed.

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,
In particular, it is suitable for twist groove processing such as drills and end mills made of an ultra-high pressure sintered body.

[0002]

2. Description of the Related Art Conventionally, a drill, an end mill and the like made of an ultra-high pressure sintered body have been machined with a diamond grindstone while taking a minute cut and taking a long time.

Further, although electric discharge machining is also carried out without relying on grinding for groove machining, this machining is applied by die-cutting or wire cutting.

[0004]

However, in the case of diamond grinding, there is a problem that the cutting and feeding cannot be made large and the grindstone is greatly worn, so that the grindstone must be frequently formed.

On the other hand, the conventional electric discharge machining has a problem that it is a two-dimensional machining and a three-dimensional twist groove cannot be machined.

In view of the above, the present invention intends to provide an electric discharge machining apparatus which employs the same mechanical structure as that of a groove grinder and can be applied to three-dimensional twist groove machining.

[0007]

The electric discharge machine of the present invention has an X-axis table, a Y-axis table, and a Z-axis portion, and is constructed so as to obtain the rotation of the workpiece and the rotation of the electrode. It can be processed.

Further, as the electrode, a disc-shaped rotary electrode having free-cutting property is applied and a truing tip is provided, so that the electrode can be molded on the apparatus.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the electric discharge machine of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 is a base in the form of a board, and an X on which a Y-axis table 2 is placed is mounted on the base 1.
The axis table 3 is arranged, and at the position opposite to this, Z
The shaft portion 4 is arranged. In this case, a spindle 6 for rotatably holding the work 5 is arranged on the X-axis table 3, and a holder 8 to which a truing tip 7 is attached is provided above the spindle 6. Then, the work 5 is held by the chuck 9 and is attached to the spindle 10 of the Z-axis portion 4 in the form of a disc-shaped rotary electrode 1.
Processed by 1. At the time of this electric discharge machining, oil is jetted from a nozzle (not shown).

The rotary electrode 11 is made of a material having good machinability and good electrical conductivity, such as carbon or brass. The reason why the rotary electrode 11 having a free-cutting property is applied is to make it easier to form the electrode by the truing tip 7. In this case, the rotating electrode 11 in the shape of a cup grindstone can be formed by pressing it against the truing tip 7 provided on the holder 8. If the X-axis table 3 and the Y-axis table 2 are moved by a locus controlled by NC data instead of such a manual work, the rotary electrode 11 having an arbitrary shape can be easily and accurately molded.

FIGS. 2 and 3 show a case where the work 5 rotating around the W axis is machined by the rotating electrode 11 and a case where a spiral groove is machined, respectively. Therefore, in these processes, although the set position of the rotary electrode 11 is different from the case of the molding shown in FIG. 4,
This change in the set position is performed by the vertical movement of the Z-axis portion 4. Then, in the case of forming the flat grindstone-shaped rotary electrode 11 in the case of the twist groove processing, the truing tip 12 is attached to the holder 14 provided on the attachment base 13 on the Z-axis portion 4 side.

It is to be noted that the twist groove is formed in the work 5 as shown in FIG.
In the case of, the rotation axis (W axis) of the work 5 and the work 5
It is necessary to synchronize the feed axis (X axis) of the rotating electrode 11 and the work 5 and determine the moving direction and moving speed of the rotating electrode 11 while monitoring electrical conditions. Therefore, when the state between the rotary electrode 11 and the work 5 is electrically close to open,
The physical distance between the rotating electrode 11 and the work 5 is reduced, and when the electrical state between the rotating electrode 11 and the work 5 is close to a short circuit, the physical distance between them is increased. And speed control.
Further, the discharge state detection sensor (not shown) is used for the rotary electrode 11 and the work 5 used in a normal electric discharge machine.
A method may be adopted in which a voltage, a machining current or a discharge pulse between them is detected, and this is compared with a set value to determine the feeding or retracting direction of the electrode and the speed.

A power source for electric discharge machining (not shown) is a pulse power source using a switching transistor, RC or L.
An electric discharge machining pulse using an RC circuit may be used. In this case, it is advisable to use them according to the processing conditions for roughing, semi-finishing and finishing.

In FIG. 5, a grinding wheel 15 is mounted coaxially with the rotary electrode 11. This is to improve the finished surface by removing a slight work-affected layer of about several microns generated by electric discharge machining with the grinding wheel 15. That is, after performing the electric discharge machining for finishing with the rotary electrode 11, the electrode axis is shifted while the work 5 is still attached to the spindle 6, and then the trajectory of the grinding wheel 15 is set exactly the same as the trajectory of the electric discharge machining. This is because it is possible to remove a process-altered layer. In the processing at this time, since the work-affected layer is a very thin layer, the abrasion of the grinding wheel 15 does not become a serious problem.

The electric discharge machine of the present invention can perform not only the electric discharge machining of the twist groove found in a normal drill but also the electric discharge machining of the twist groove in a taper drill. This is achieved by controlling the cutting shaft for the work 5 in addition to the rotation shaft and the feed shaft of the work 5, and thus the core thickness taper.
This is because the twist groove corresponding to the power can be processed by electric discharge machining.

[0017]

As described above, according to the present invention, in the electric discharge machining apparatus including the X-axis table 3, the Y-axis table 2 and the Z-axis portion 4, the Z-axis portion 4 includes the free-cutting rotary electrode 11. Since the provided spindle 10 is arranged, there is an advantage that a twist groove such as a drill can be easily and accurately processed. Further, since the rotary electrode 11 can be molded on the machine by the truing tips 7 and 12, the workability is improved.

Further, if the grinding wheel 15 is mounted coaxially with the rotary electrode 11, there is an advantage that the work-affected layer generated by electric discharge machining can be easily removed.

[Brief description of drawings]

FIG. 1 is a conceptual plan view showing an embodiment of an electric discharge machine of the present invention.

FIG. 2 is an explanatory diagram of a case where a workpiece is cylindrically processed by a rotating electrode.

FIG. 3 is an explanatory diagram of a case where a twisted groove is formed on a work by a rotating electrode.

FIG. 4 is an explanatory diagram for forming a rotary electrode.

FIG. 5 is an explanatory diagram of a case where a grinding wheel is provided coaxially with a rotating electrode.

[Explanation of symbols]

 1 Base 2 Y-axis table 3 X-axis table 4 Z-axis part 5 Workpiece 6 Spindle 7 Truing tip 8 Holder 9 Chuck 10 Spindle 11 Rotating electrode 12 Truing tip 13 Mounting table 14 Holder 15 Grinding wheel

Claims (3)

[Claims] 1. A Y-axis table 2 equipped with a spindle 6 is placed on an X-axis table 3, and Z is attached to a work 5 rotatably held by the spindle 6.
In the electric discharge machining device in which the shaft portion 4 is positioned so as to face each other, the Z-axis portion 4 has a spindle 10 for imparting rotation on its side portion, and the spindle 10 has a disc-shaped free-cutting property. The electric discharge machining device is characterized in that the rotating electrode 11 is attached. 2. The apparatus according to claim 1 is provided with tooling tips 7 and 12 for forming an electrode so that the free-cutting rotary electrode 11 can be formed on the machine. Electric discharge machine. 3. An electric discharge machine, wherein the spindle 10 according to claim 1 or 2 is provided with a grinding wheel 15 coaxially mounted with a rotary electrode 11.