JPS5916893B2 - Servo head of electrical discharge machining equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION 5 The present invention relates to a servo head for an electric discharge machining apparatus.

In the servo head of a conventional electric discharge machining apparatus, a fitting for a replacement electrode is provided at the tip of the servo head, and the fitting allows a desired electrode to be mounted on the servo head.

In this case, for example, in the case of a machining electrode that requires accurate angle adjustment after being attached to a servo head, such as when drilling a hole using a full-form electrode, the machining electrode must be placed at a predetermined angle relative to the quill of the servo head. The first requirement is that the fixture be mounted accurately so as to maintain the proper positional relationship, so it is preferable that the fixture be as large as possible. However, when rotating the machining electrode at high speed, such as when accurately drilling a long and narrow hole using a circular electrode or when performing edge machining,
It is preferable to reduce the weight i0 of the rotating part as much as possible, and therefore the fixture is required to be small and lightweight. In this way, contradictory conditions are required for the servo head of the electrical discharge machining device, especially the mounting part of the machining electrode, depending on the machining electrode used, so it is better to place emphasis on one of the five conditions. Or, a compromise between both conditions had to be found and the structure of the mounting bracket had to be determined, making it impossible to obtain a servo head with satisfactory characteristics. This trend is
This is particularly noticeable in electric discharge machining equipment equipped with an automatic electrode exchange device. An object of the present invention is to provide an electric discharge machining apparatus that can accurately position and attach a desired machining electrode to a servo head, and that can rotate only the machining electrode at high speed without rotating the mounting bracket. Our purpose is to provide servo heads.

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments. FIG. 1 shows an embodiment of a servo head of an electric discharge machining apparatus according to the present invention.

This servo head 1 includes a main body 3 having a cylindrical quill 2, and a part of the main body 3 has a ball connected to a rotating shaft (not shown) of a servo pulse motor 5 fixed to a column main body 4. A screw 6 is engaged with the quill 2, which moves the quill 2 up and down as the pulse motor 5 rotates to adjust the length of the discharge gap between the discharge machining electrode and the workpiece (both not shown). It is becoming possible to do so. A hollow rotating shaft 9 of a fixture support member 8 for supporting a fixture 7 for attaching a processing electrode to the head 1 is housed in the hollow portion 2a of the quill 2. Hollow part 2
Ball bearings 1 provided near the ends of a
It is rotatably supported by 0 and 11. A gear 12 is fixed to one end of the hollow rotating shaft 9.
is a pulse motor 1 for angle indexing fixed to the main body 3.
It meshes with the drive gear 15 fixed to the rotating shaft 14 of No. 3 (
・Ru. Therefore, by rotating the pulse motor 13, the fixture support member 8 can be rotated, and the angular position of the processing electrode attached to the fixture 7 can be determined at a desired position. This set angular position can be detected electrically by providing an encoder on the pulse motor 13, for example.
can be controlled. The processing electrode (not shown) is attached to an electrode side mounting bracket 16 in which receiving grooves 16a and 16b are formed in shapes corresponding to the protrusions 7a and 7b provided on the mounting bracket 7.
It is attached by a chuck 17, and the receiving grooves 16a, 16b of the electrode side mounting bracket 16 are aligned with the protrusions 7a, 7b of the mounting bracket 7, and the mounting bracket 7 is fitted.
By supplying an excitation current to the electromagnetic coil 7c provided in the magnetic coil 7c, both mounting fittings can be attached by the attraction force generated by the electromagnetic attractive force. In the illustrated example, only two protrusions are provided on the mounting bracket 7, but any number of protrusions may be provided and corresponding receiving grooves may be provided in the mounting bracket 16.

A rotating shaft 18 is further disposed in the hollow portion 9a of the hollow rotating shaft 9, and this rotating shaft 18 is rotatably supported by bearings 19 and 20 so that its axis coincides with the axis of the hollow rotating shaft 9. There is. One end of the rotating shaft 18 is connected via a spring-type coupling link 21 to a rotating shaft 23 of a motor 22 that is fixed to the main body 3 and capable of high-speed operation, and the other end is driven by the rotating shaft 18. Rotating axis (described later)
An engaging pawl 24 is formed for coupling with. An adapter 25 shown in FIG. 2 is used to rotate the processing electrode at high speed by the rotating shaft 18 which is rotated by the motor 22 at a high speed (for example, about 1800 [R.p.m.]). The adapter 25 includes a mounting bracket 26 similar to the mounting bracket 16 that is fitted into the fixture 7, and a frame 27 fixed to the mounting bracket 26. The frame 27 is formed into a substantially cylindrical shape, and a rotary shaft 28 is rotatably supported in a hollow portion 27a by bearings 29 and 30 so as not to move in the axial direction. Furthermore, this rotating shaft 2
8 is positioned such that the axis of the rotating shaft 28 is aligned with the axis of the rotating shaft 18 when the adapter 25 is fitted into the fixture 7, and a groove 31 formed at one end of the rotating shaft 28
The engaging claw 24 engages in the rotation shaft 2, and the rotational force of the rotation shaft 18 is applied to the rotation shaft 2
8. Here, the rotating shaft 18
and the rotating shaft 23 of the motor 22 are connected to the spring type coupling 21.
Therefore, even if the engaging pawl 24 does not engage the groove 31 when the fixture 7 and the adapter 25 are fitted, the pawl 24 is connected to the rotation shaft 1 due to the spring-type coupling 21.
When the rotary shaft 18 starts to rotate, the direction of the claw 24 and the groove 3 are changed due to this pressure contact force.
1, the pawl 24 is engaged in the groove 31. A chuck 32 for gripping a processing electrode is provided at the other end of the rotating shaft 28.
A processing electrode (not shown) held by 2 can be rotated at high speed. In this way, since the rotary shaft 18 for high-speed rotation is coaxially disposed within the hollow rotary shaft 9 for angle indexing, for example, when machining is performed using a full-form electrode, the hollow rotary shaft 9 Attach the full-type electrode via the mounting bracket 16 corresponding to the fixture 7 at the lower end of the pulse motor 1.
3 allows the angle of the entire mold electrode to be adjusted. In this case, the full-type electrode can be attached to the head by fitting the fixture 7, which does not rotate at high speed, and the corresponding fixture 16, so the dimensions of the fixture 7 and the fixture 16 can be increased to improve accuracy. It is possible to obtain a fitting structure with a high degree of fit, thereby making it possible to perform angle indexing with higher precision. On the other hand, by attaching the adapter 25 to the fixture 7, the processing electrode held by the chuck 32 can be
The mounting fixture 7 and the mounting bracket 16 can be rotated at high speed by the rotating shaft 18 without rotating them. As can be seen from the drawing, the rotating shaft 28 with a relatively small diameter rotates at high speed.
Therefore, unlike the high-speed rotation of fixtures that are large in size and weight, the processing electrode can be rotated extremely stably at high speed. For example, when rotating a small-diameter circular electrode to drill a narrow hole. It is suitable for As mentioned above,
In addition to being able to accurately index the angle of the electrode, the use of the adapter 25 allows for high-speed rotation of the electrode without any hindrance, making it especially possible to automatically exchange various processing electrodes. It is suitable as a servo head for electrical discharge machines. According to the present invention, as described above, accurate angular motion can be created by arbitrarily selecting high-speed rotational motion with one servo head, depending on the machining mode using the attached electrodes. Therefore, it is possible to perform good electrical discharge machining operations.

[Brief explanation of drawings]

FIG. 1 is a partially sectional side view of an embodiment of the present invention;
FIG. 2 is a sectional view of an adapter for rotating the processing electrode at high speed using the apparatus shown in FIG. 1... Servo head, 2... Quill,
3...Body, 7...Mounting tool, 8...
... Fixture support member, 9 ... Hollow rotating shaft, 1
3...Pulse motor, 16...Mounting bracket, 17...Chuck, 18...Rotating shaft, 19, 20...Bearing, 22...
...Motor, 25...Adapter, 26...
...Mounting bracket, 28... Rotation shaft.

Claims (1)

[Scope of Claims] 1. In a servo head of an electric discharge machining device in which a desired machining electrode can be attached to a pair of fixtures, one fixture of the pair of fixtures is fixed. A fixture support means, a rotation drive means for rotating the fixture support means for angle adjustment, a rotation shaft disposed within the fixture support means for the purpose of rotating the processing electrode at high speed, and the rotation shaft. A servo head for electrical discharge machining equipment, characterized in that it is equipped with a high-speed rotation drive means for rotating at high speed. 2. A patent characterized in that the fixture support means includes a hollow rotating shaft to which the one fixture is fixed to one end, and the hollow rotating shaft is rotatably supported on the main body of the servo head. A servo head for an electric discharge machining apparatus according to claim 1. 3. The servo head of an electric discharge machining apparatus according to claim 2, wherein the rotating shaft is coaxially arranged within the hollow rotating shaft. 4. In a servo head of an electrical discharge machining device, in which a desired machining electrode can be mounted using a pair of fixtures, a fixture support means to which one fixture of the pair of fixtures is fixed; a rotary drive means for rotating the fixture support means for angle adjustment; a rotary shaft disposed within the fixture support means for the purpose of rotating the processing electrode at high speed; and a high speed rotary drive means for driving the rotary shaft to rotate at a high speed. The present invention is characterized by comprising: a rotational drive means; and an adapter that is attached to the one of the fittings by the other fitting of the pair of fittings and has a transmission means for transmitting the rotational output of the rotating shaft to the processing electrode. Servo head of electrical discharge machining equipment. 5. Claim 4, wherein the transmission means is a rotating shaft rotatably supported by the frame of the adapter, one end of which is connected to the rotating shaft and the other end of which grips the processing electrode. The servo head of the electrical discharge machining device described in Section 1.