JP2562597B2 - Wire source - Google Patents

Description

The present invention relates to a wire saw that drives a wire having an abrasive attached thereto to perform precision machining such as cutting or grooving an object to be machined.

[Prior Art] A device called a wire saw is used for grooving and cutting a magnetic head and a vibrator, or for precision cutting such as cutting a ceramic or a silicon wafer. This wire saw has a drive roller 10 and two head rollers 20 rotatably attached to a frame S as shown in FIG.
A large number of one wire 30 is wound around these three rollers at regular intervals to form a wire row 31 between two head rollers 20. A guide roller 40 for guiding the wire 30 and an abrasive material. It was equipped with a spray nozzle (not shown) for adhering. By driving the wire 30 in the direction of the arrow by a winding roller (not shown) while reciprocally rotating the drive roller 10, the wire row 31 is linearly reciprocated, and the workpiece H is pressed against the wire row 31. By interposing an abrasive between them, cutting and grooving can be performed according to the pitch width of the wire row 31.

The wire 30 was a special piano wire with a diameter of about 0.08 to 0.25 mm, and the abrasive used was a mixture of GC abrasive grains and special cutting oil.

The head roller 20 constituting such a wire saw has a surface member 22 having a large number of grooves 21 for guiding the wire 30 and a core material 23 made of metal, as shown in a partially broken sectional view in FIG. The surface member 22 was made of resin such as nylon 66 and UMPE resin. Further, the drive roller 10 is also a combination of a surface member made of a resin having a groove formed therein and a core material made of a metal.

[Problems of conventional technology]

However, in such a conventional wire saw, since the groove portions of the drive roller 10 and the head roller 20 are made of resin, the wire 30 is severely worn. When the wear increases, the wire 30 is difficult to enter into the groove 21 and the resistance for driving the wire 30 increases, which may eventually break the wire.
The drive roller 10 and the head roller 20 had to be replaced with new ones in about a week, which was troublesome and costly.

Further, as described above, the cutting width of the workpiece H is determined by the pitch width of the wires 30 in the wire row 31,
Since this depends on the pitch width of the groove 21 formed in the two head rollers 20, the pitch width of the groove 21 must be set to a very high precision. However,
Since the resin has a large coefficient of thermal expansion, the pitch width of the groove 21 will change significantly due to temperature changes during groove processing, subsequent annealing, or during use, and excellent dimensional accuracy for highly accurate cutting. Was difficult to keep.

Furthermore, since the resin has a low hardness and is easily deformed, the groove portion may be easily deformed during handling of the drive roller 10 and the head roller 20, and the dimensional accuracy of the pitch may be deteriorated.

[Means for solving problems]

Therefore, in view of the above problems, a plurality of grooves are provided on the surface,
At least the groove is arranged in a triangular shape with a cylindrical roller made of ceramic, cermet, or sapphire, and a wire is formed by guiding the wire into the groove of these rollers. The wire saw is configured so that an object to be processed can be cut with an abrasive while reciprocating with movement.

〔Example〕

A drive roller and a head roller that compose the wire saw according to the embodiment of the present invention will be described below with reference to the drawings.

The head roller 20 shown in FIG. 1 (a) is a substantially cylindrical body entirely made of ceramics such as alumina, zirconia, silicon carbide, silicon nitride or cermet, and has a groove 21 for guiding the wire 30 to the outer peripheral surface. About 170 are provided, and through holes 22 for mounting are formed inside.
As shown in the enlarged view of FIG. 1 (b), the groove 21 has a curved surface with a radius of curvature of about 0.05 mm to improve the stability of the wire 30, and the pitch p of the groove 21 has an error of 3 μm or less. It is processed with high precision.

The drive roller 10 shown in FIG. 2 is formed by combining a surface member 12 made of ceramic or cermet having grooves 11 and a core member 14 made of metal having a through hole 13 for mounting.

Further, the drive roller 10 shown in FIG. 3 is formed by connecting a surface member 12 made of sapphire single crystal having a groove 11 to the outside of a core member 14 made of ceramic or metal having a through hole 13 for mounting. It is also.

The above-described embodiments shown in FIGS. 1 to 3 show only one of the drive roller 10 and the head roller 20, respectively, but needless to say, they can be applied to both rollers. The grooves 11 and 12 are processed using a diamond wheel.

As shown in Table 1 by comparing the characteristics of various ceramics, cermets, sapphires and resins, the ceramics, cermets and sapphires used in the examples of the present invention have a higher hardness and a smaller coefficient of thermal expansion than resins. I understand. Therefore, the drive roller 10 and the head roller
If the 20 grooves 11 and 21 are formed of these materials, the wear resistance is high and the change in dimensional accuracy due to temperature change is small, so that highly accurate cutting can be performed.

Next, as an embodiment of the present invention, a drive roller 10 and a head roller 20 in which a metal core material and a surface member made of alumina as shown in FIG. 2 were combined were prototyped and incorporated into an actual wire saw. As a comparative example, a drive roller 10 and a head roller 20 each having a groove formed of conventional nylon 66 are used.
We prepared a wire saw using and used both for cutting the magnetic head under the same conditions. As a result of continuous use for 8 hours a day and 21 days a month, the comparative example had to be replaced with a new one after one week, whereas the inventive example had 6 months. It was kept in a usable state to some extent.

Further, in the head roller 20, the dimensional accuracy of the pitch p of the groove 21 is limited to 3 μm, and the conventional nylon 66 is strict in temperature control because the dimensional accuracy exceeds the limit with a temperature change of about 0.7 ° C. In contrast to this, the embodiment of the present invention formed of alumina has a temperature of about 7 ° C.
Since the dimensional accuracy is within the limit even when the temperature changes, the temperature control was easy.

In the above examples, only those in which the groove portion was formed of alumina were shown, but similar results were obtained even in the case of other ceramics such as zirconia, silicon carbide, silicon nitride, etc., or cermet, sapphire or the like. In particular, those in which the groove portion was formed of sapphire, silicon carbide, silicon nitride, etc. were more excellent in abrasion resistance and excellent.

Further, it was more effective if not only the drive roller 10 and the head roller 20 but also the guide roller 40 was formed of ceramic, cermet or the like.

〔The invention's effect〕

As described above, according to the present invention, a plurality of grooves are formed on the surface, and the wire is guided by a cylindrical roller formed of any one of ceramic, cermet and sapphire, and the groove is formed. By constructing the wire saw by cutting the object to be processed with abrasive while driving the wire, not only can the groove be worn for a long period of time due to the large wear resistance, but also the groove due to temperature change can be used. Since the change in the dimensional accuracy of the pitch width is small and there is no deformation during handling, it is possible to perform high-precision cutting without particularly strict temperature control, and to improve the quality of the processed object. It is possible to provide a wire saw having the features of.

[Brief description of drawings]

FIG. 1 (a) is a partially cutaway side view showing a head roller constituting a wire saw according to an embodiment of the present invention, and FIG. 1 (b) is an enlarged view of a portion A in FIG. 1 (a). 2 and 3 are partially cutaway side views showing drive rollers constituting a wire saw according to another embodiment of the present invention. FIG. 4 is a schematic perspective view showing a main part of a wire saw, and FIG. 5 is a partially cutaway side view showing a head roller of a conventional wire saw. 10: Drive roller, 20: Head roller 30: Wire, H: Object to be processed

Claims (1)

(57) [Claims] 1. A roller having a plurality of grooves on the surface thereof is arranged in a triangular shape, and a wire is formed by guiding a wire into the groove of these rollers, and the abrasive wire is reciprocally moved. A wire saw for cutting or grooving an object to be processed using, wherein at least the groove portion of the roller is formed of any one of ceramic, cermet and sapphire.