JPH0316845Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wire electrode supply device used in a wire electrical discharge machine.

[Prior Art] A wire electrical discharge machine uses a wire electrode made of a thin copper wire, brass wire, tungsten wire, etc. wound around a wire reel.

FIG. 4 is a perspective view showing the main parts of the wire electrode supply section. The wire electrode 1 is guided from a wire reel 2 via a tension roller 3 to a processing section (not shown) where a workpiece is placed, and then drawn into a wire recovery device. In a wire recovery device (not shown), a drive roll connected to a motor pulls the wire electrode, and an electromagnetic powder brake 4 is connected to the tension roller 3 to apply a strong constant tension to the wire electrode 1A in the processing section. Tension roller 3 applies strong tension to the wire electrode 1 and tension roller 3 at the processing section.
If the wire electrode 1 from the wire reel 2 to the tension roller 3 becomes loose or the tension changes suddenly, the tension of the wire electrode 1A in the processing section will fluctuate. This causes inconveniences such as changing the feeding speed of the wire electrode and causing wire breakage. For this reason, a constant tension (pretension) is applied to the wire electrode 1 from the wire reel 2 to the tension roller 3,
A mechanism that can smoothly pull out the wire electrode 1 is required.

In the conventional wire electrode supply device, as shown in FIG.
Alternatively, the motor 6 may generate a constant torque to give pretension to the wire electrode 1, or the wire reel shaft 10 holding the wire reel body 2' may have a tapered shape at both ends, as shown in FIGS. 6 and 7. The receiving portions 10A, 10B are provided, and the receiving portions 10A, 10B are provided.
10B is the same tapered shaped contact portion 12A, 13A
The contact portions 12A, 13 are pressed and clamped by support shafts 12, 13 having
Pretension was given to the wire electrode 1 by the frictional force between A and the receiving parts 10A and 10B.

The former mechanism has the problem of requiring expensive parts such as the constant torque damper 5. In the latter mechanism, the wire reel shaft 10 is supported by sliding contact between the tapered surfaces of the receiving parts 10A, 10B and the contact parts 12A, 13A, so that the centering of the support shafts 12, 13 and the wire reel shaft 10 can be precisely performed. If this is not done, the contact portion 12 will rotate as the wire reel shaft 10 rotates.
There was a problem in that the frictional force between A, 13A and the receiving parts 10A, 10B fluctuated, resulting in uneven rotation of the wire reel 2.

[Problem that the invention attempts to solve]

The present invention was developed to solve the above problems, and it applies load torque to the wire reel due to stable frictional force without the need for strict centering, and smoothly wires the wire while giving pretension to the wire electrode. It is an object of the present invention to provide a wire electrode supply device having a simple structure from which electrodes can be drawn out.

[Means for solving problems]

FIG. 1 is a sectional view schematically showing the outline of the present invention. In order to solve the above problems, in this invention,
A wire reel 2 around which a wire electrode is wound, and a support shaft that contacts both ends of the wire reel 2 with a predetermined pressing force, rotatably supports the wire reel 2, and provides an appropriate frictional force to the wire reel. 2
2, 23, a pair of receiving portions 21, 21' each having a tapered recess is provided on one of the wire reel 2 and the support shafts 22, 23. There is provided a wire electrode supply device characterized in that the other is provided with spherical contact portions 22A and 23A that abut the pair of receiving portions 21 and 21', respectively.

[Effect]

According to the configuration of the present invention, the wire reel 2 is supported axially by the contact between the tapered receiving portions 21, 21' and the spherical contact portions 22A, 23A. There is an automatic centripetal action due to sliding contact, and the wire reel 2 can rotate smoothly even if the left and right support shafts 22, 23 are not precisely centered. Moreover, the receiving part 21,
Since the contact between the support shafts 21' and the support shafts 22 and 23 is a line contact, there is almost no variation in the contact area and a stable frictional force can be provided.

〔Example〕

An embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a front view of the wire electrode supply device according to the present invention, and FIG. 3 is a sectional view of the receiving portion.

The wire reel shaft 20 has a collar portion 20A at the right end, and a thread 20B at the left end. The wire reel shaft 20 is inserted into the wire reel main body 2' around which the wire electrode 1 is wound, and the wire reel main body 2' and the wire reel shaft 20 are assembled together by tightening the disk-shaped nut 24 from the right end.
It constitutes a wire reel 2.

A circular recess is formed in both end surfaces of the wire reel shaft 20, and annular bushes 25, 2 are provided in the recess.
5' is fitted. Annular bush 25,2
5' is made of a synthetic resin such as Teflon or an oil-impregnated bearing material, and its inner diameter has a tapered bearing surface 25A,
25'A is formed. circular bush 25,
Reference numeral 25' constitutes a tapered recessed receiving portion provided at both ends of the wire reel.

A support shaft 2 that pivotally supports the right end of the wire reel shaft 20
3 is fastened to a bracket 31 fixed to a base 30 with a nut 32. The fixed support shaft 23 has a spherical contact portion 23A at its shaft end.
The contact portion 23A contacts the bearing surface 25'A of the bush 25'.

A support shaft 2 that pivotally supports the left end of the wire reel shaft 20
2 is fitted into the sleeve 33, and the sleeve 3
3 is fitted into a support base 34 fixed to the base 30 so as to be slidable in the axial direction. A disk-shaped operating handle 35 is attached to the rear end of the support shaft 22.
2 and the sleeve 33. The sleeve 33 and the support shaft 22 are strongly biased by a compression spring 36 in the direction of shaft advancement (rightward in the drawing). Then, depending on the rotational position of the operating handle 35, the support shaft 22
It is possible to select a rotational position in which the rotational position can be freely advanced by the pressing force of the compression spring 36, and a rotational position in which it is locked at the backward end. A support shaft 22 that is movable in the axial direction has a spherical abutment portion 2 at its tip.
2A, and this contact portion 22A contacts the bush 25 of the wire reel shaft 20.

To attach the wire reel 2, pull the operating handle 35 to the left in the drawing and then turn it to the right to lock the support shaft 22 in the retracted state. In this state, move the wire reel 2 onto the axes of the support shafts 22 and 23 and turn the operating handle 35 to the left to release the lock. It comes into contact with the bush 25 and presses it. Due to this pressing force, the bush 25' at the right end of the wire reel shaft 20 is also pressed against the support shaft 23, and the wire reel 2 is pivotally supported. Then, the tapered bearing surfaces 25A, 25'A of the annular bushes 25, 25' forming the spherical contact parts 22A, 23A of the left and right support shafts 22, 23 and the receiving parts.
The wire reel 2 is in sliding contact with a constant pressing force from the compression spring 36, and the automatic centripetal action caused by the sliding contact between the spherical surface and the tapered surface supports the wire reel 2 on the correct central axis and provides an appropriate frictional force to the wire reel 2.

When the wire electrode 1 is pulled out, the support shafts 22 and 23 and the bush 2 are rotated as the wire reel 2 rotates.
Appropriate pretension can be given to the wire electrode 1 by receiving a predetermined tension determined by the frictional force caused by sliding contact with the wire electrodes 5 and 25'.

In the embodiment described above, the wire reel main body 2' and the wire reel shaft 20 are constructed separately, and the wire reel shaft 20 is provided with annular bushes 25, 25' which serve as receiving parts.
However, it is also possible to configure the wire reel body 2' and the wire reel shaft 20 integrally.

[Effect of idea]

As explained above, according to the present invention, the wire reel is pivotally supported by the sliding contact between the spherical contact part and the tapered receiving part with a predetermined pressing force, so that the support shaft is precisely This has the excellent effect that a stable load torque can be applied to the wire reel without the need for precise centering, and the wire electrode can be drawn out smoothly while giving a predetermined pretension to the wire electrode.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the outline of the present invention, Fig. 2 is a front view of the wire electrode supply device according to the present invention, and Fig. 3 is a sectional view showing an outline of the present invention.
The figure is a sectional view of the main part of FIG. 2, FIG. 4 is a perspective view showing the main part of the wire electrode supply section, and FIGS. 5 to 7 are sectional views showing the conventional wire electrode supply device. 1... Wire electrode, 2... Wire reel, 3...
...Tension roller, 20...Wire reel shaft,
21, 21'...Receiving part, 22, 23...Support shaft,
22A, 23A...Spherical shaped contact portion, 2
5, 25'... Bush as a receiving part, 25A,
25'A...Tapered bearing surface, 36...
compression spring.

Claims (1)

[Claims for Utility Model Registration] 1. A wire reel wound with a wire electrode, and a wire reel that is in contact with both ends of the wire reel with a predetermined pressing force to rotatably support the wire reel, and that is suitable for the wire reel. In a wire electrode supply device for a wire electrical discharge machine equipped with a support shaft that applies a frictional force, one of the wire reel and the support shaft,
A pair of receiving parts with a tapered recess is provided,
A wire electrode supply device characterized in that the other is provided with a spherical contact portion that abuts the pair of receiving portions, respectively. 2 Utility model registration claim 1, characterized in that either or both of the receiving part and the contact part are formed of a synthetic resin material.
Wire electrode supply device as described in . 3. The wire electrode device according to claim 1, wherein either the receiving portion or the contact portion is formed of an oil-impregnated bearing material.