JP2011167836A - Wire saw device and cutting method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wire saw device with high reliability achieved in a long service life of a wire and high in processing accuracy. <P>SOLUTION: A Langevin type ultrasonic transducer 13 to which a magnet 20 is bonded by epoxy resin is positioned 1 mm away from a wire 2 having a diameter of approximately 120 μm. A supplying device 10 for spraying slurry or a cutting fluid 11 is arranged at a position opposed to the Langevin type ultrasonic transducer 13 with the wire 2 therebetween. The slurry or the cutting fluid 11 sprayed from the supplying device 10 is accumulated on surfaces of the wire 2 and the magnet 20 as indicated by the dotted line. The ultrasonic vibration of the Langevin type ultrasonic transducer 13 is propagated to the magnet 20, and then reliably propagated through the slurry or the cutting fluid 11 to reach the wire 2, thereby ultrasonically vibrating the wire 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wire saw device for cutting a brittle material such as a sapphire single crystal with a wire and a cutting method using the same.

  In general, in a wire saw apparatus, a plurality of processing rollers are arranged at a predetermined interval, and a plurality of annular grooves are formed on the outer periphery of the rollers at a predetermined pitch, and one wire is interposed between the annular grooves. Are wound in order. Then, along with the rotation of the processing roller, while the wire is running, a slurry containing free abrasive grains is supplied onto the wire, and in this state, the object to be cut is pressed against the wire to contact the object. It is configured to cut.

  In the wire saw apparatus configured as described above, various proposals have been made in order to improve the cutting ability. For example, in Patent Document 1, an auxiliary roller having a concavo-convex portion on the outer periphery is provided so as to come into contact with a wire in the vicinity of an object to be cut, and the rotation of this roller directly imparts vibration to the wire up and down. Yes.

  However, in the above-described wire saw device, when the wire and the auxiliary roller are in contact with each other, the uneven portion is flattened on the outer periphery of the auxiliary roller, so that the vibration of the wire is reduced. For this reason, frequent replacement of the auxiliary roller is necessary. Further, in order to efficiently cut the object to be cut, it is preferable to apply a vibration of 15 KHz or more to the wire, but it is difficult to provide an uneven portion that generates a desired frequency and amplitude on the auxiliary roller.

  Therefore, the wire saw device of Patent Document 2 has been proposed. In this wire saw device, a pair of magnetic field generators are provided on both sides in the wire traveling direction in a processing area of an object to be cut. And a predetermined drive output is supplied with respect to a magnetic field generator, a magnetic field generator is operated, a wire is attracted | sucked intermittently, and a vertical vibration is provided with respect to a wire.

  According to the present invention, since the vibration means for applying vibration to the wire through a minute interval is provided close to the wire row, a sufficient amount of slurry is generated between the wire and the workpiece by the vibration of the wire. It can be supplied and efficient cutting can be performed. Moreover, since the vibration applying means for applying vibration to the wire does not come into contact with the wire, the vibration applying means is not cut or worn by the wire, and the durability can be improved.

JP-A-8-99262 JP 2001-62700 A

Ultrasonic Handbook Editorial Committee, “Ultrasonic Handbook”, Maruzen Co., Ltd., August 1999, p679-684 Japan Electromechanical Industry Association, "Ultrasonic Engineering", Corona Co., Ltd., 1993, p218-229

  In the wire saw device described in Patent Document 2 described above, a vibration force that is alternatingly applied to the wire by the magnetic field generator from the AC power source is applied without contact with the wire. Is difficult to give. And it is difficult to adjust the amplitude width of the wire. It is also difficult to control the direction of vibration.

  In addition, an AC power source for generating a magnetic field has low efficiency and generates heat in an ultrasonic region of 15 KHz or higher, which may increase the temperature of the wire. An increase in the temperature of the wire also causes deterioration of processing accuracy and shortens the life of the wire.

  An object of the present invention is to provide a wire saw device that has high processing accuracy and can improve the cutting speed, and a cutting method using the same.

  The present invention relates to a wire saw device for cutting a workpiece by pressing the workpiece against a traveling wire supplied with a slurry containing loose abrasive grains or a traveling wire with fixed abrasive grains, A slurry or cutting fluid is interposed between the ultrasonic vibrators, and an alternating voltage is applied to the ultrasonic vibrators.

  The present invention is also a wire saw device in which a slurry or cutting fluid supply device is positioned at a position facing the ultrasonic transducer with a wire interposed therebetween.

  The present invention also provides a wire saw device in which a slurry or cutting fluid supply device is positioned on the upper side of the wire and the ultrasonic vibrator is positioned on the lower side of the wire.

  The present invention also provides a wire saw device for joining a magnet to the ultrasonic transducer.

  By cutting using the wire saw device of the present invention, high-precision and high-speed processing becomes possible, and the wire has a long life.

It is a perspective view which shows the wire saw apparatus of the structure of this invention. It is a top view which shows the detail of a wire, a Langevin type ultrasonic transducer | vibrator, and a supply apparatus. It is a side view which shows the detail of a wire, a Langevin type ultrasonic transducer | vibrator, and a supply apparatus. It is a top view of a Langevin type ultrasonic transducer. It is a side view of a Langevin type ultrasonic transducer. It is the schematic of the apparatus which demonstrates that the ultrasonic vibration of the Langevin type ultrasonic vibrator which joined the magnet to the wire through the liquid propagates. It is the schematic of the apparatus which demonstrates that the ultrasonic vibration of a Langevin type ultrasonic transducer | vibrator propagates to a wire through a liquid. It is the top view which joined the proximity board to the tip of the Langevin type ultrasonic transducer which joined the magnet. It is the side view which joined the proximity board to the tip of the Langevin type ultrasonic transducer which joined the magnet.

  Hereinafter, an embodiment of a wire saw apparatus according to the present invention will be described with reference to the perspective view of FIG. The wire saw device 1 has three multi-groove rollers 3a, 3b, 3c around which one wire 2 is wound, and configures a wire row around which the wire 2 having a diameter of, for example, about 120 microns is wound around each multi-groove roller The wire 2 of this wire row is reciprocated by driving a drive-side multi-groove roller 3a driven by a wire drive motor 4. Further, it has bobbins 5a and 5b for winding and feeding the wire 2. A plurality of grooves provided on the surfaces of the multi-groove rollers 3a, 3b, and 3c are omitted for convenience of drawing. Further, a Langevin type ultrasonic vibrator 13 for applying ultrasonic vibration to the wire 2 and a supply device 10 for ejecting slurry or cutting fluid 11 are installed.

  Next, a Langevin type ultrasonic transducer 13 for applying ultrasonic vibration to the wire 2 and a supply device 10 for ejecting slurry or cutting fluid 11 will be described with reference to the plan view of FIG. 2 and the side view of FIG. A Langevin type ultrasonic transducer 13 in which a magnet 20 is bonded with an epoxy resin at a distance of about 1 mm from a wire 2 having a diameter of about 120 μm is positioned. And the supply apparatus 10 which ejects the slurry or the cutting fluid 11 in the position which opposes the Langevin type ultrasonic transducer | vibrator 13 on both sides of the wire 2 is installed. Here, in order to hold the slurry or cutting fluid 11 on the surface of the magnet 20-, the slurry or the cutting fluid 11 is directly ejected from the supply device 10 onto the surface of the magnet 20.

  Slurry or cutting fluid 11 ejected from the supply device 10 accumulates on the surfaces of the wire 2 and the magnet 20 as indicated by dotted lines in FIGS. By storing the slurry or cutting fluid 11 on the surface of the magnet 20, the wire 2 is always in contact with the slurry or cutting fluid 11. Then, the ultrasonic vibration of the Langevin type ultrasonic transducer 13 propagates to the magnet 20 and reliably propagates the slurry or the cutting fluid 11 to reach the wire 2 and ultrasonically vibrates the wire 2. That is, in order to keep the slurry or cutting fluid 11 in contact with the wire 2 at all times, the supply device 10 is positioned above the wire 2, and the ultrasonic vibrator 13 is attached to the wire 2 to receive the slurry or cutting fluid 11 under the wire 2. Position 2 below.

  Details of the ultrasonic transducer 13 used here will be described with reference to a plan view of FIG. 4 and a side view of FIG. The ultrasonic transducer 13 is called a Langevin type ultrasonic transducer, and between the front mass 14 made of aluminum alloy and the rear mass 15 having a female screw made of aluminum alloy, piezoelectric ceramics 16a and 16b and phosphor blue. Copper electrode plates 12 a and 12 b are integrated by fastening with steel bolts 17. Thereafter, a magnet was joined to the Langevin type ultrasonic vibrator by an epoxy resin. The phosphor bronze electrode plates 12a and 12b are connected to lead wires (not shown) by solder. The other lead wire is connected to an ultrasonic oscillator (not shown).

  The actual shape of the ultrasonic transducer 13 will be described. The Langevin type ultrasonic transducer 13 has a diameter of 25 mm and a length of 91 mm. The magnet 20 to be joined to the Langevin type ultrasonic transducer 13 is made of neodymium iron and has a diameter of 25 mm and a length of 5 mm. The resonance frequency of the Langevin type ultrasonic transducer 13 in which the magnet 20 is bonded with an epoxy resin was about 23.7 KHz.

  In order to demonstrate that ultrasonic vibration propagates to the wire through the liquid, an experimental apparatus as shown in FIG. 6 is created.

  The wire 2 was passed between the multi-groove roller models 19a and 19b, and 400 g weights 22a and 22b were connected to both ends of the wire 2 as loads. Then, a sapphire ingot having a diameter of about 51 mm is brought into contact with the center of the wire. A Langevin type ultrasonic vibrator 13 in which a magnet 20 is bonded with an epoxy resin is installed under the model 19a of a multi-groove roller and the wire 2 at a substantially central position of the sapphire ingot. The shortest distance between the wire 2 and the magnet 20 was about 1 mm. In addition, the supply device 10 is installed on the magnet 20 and on the wire 2 at about 10 mm.

  The wire 2 has a diameter of 120 μm to which abrasive grains are fixed, and the Langevin type ultrasonic transducer 13 has a diameter of 25 mm and a length of 91 mm. The magnet 20 to be joined to the Langevin type ultrasonic transducer 13 is made of neodymium iron and has a diameter of 25 mm and a length of 5 mm. The resonance frequency of the Langevin type ultrasonic transducer 13 in which the magnet 20 is bonded with an epoxy resin is about 23.7 KHz. The shortest distance between the tip of the supply device 10 and the wire 2 was about 10 mm, and the central axis of the supply device 10 and the central axis of the Langevin type ultrasonic transducer 13 were matched. The shortest distance between the wire 2 and the magnet 20 is about 1 mm. In the experiment, water 21 was used as the cutting fluid. The voltage applied to the ultrasonic transducer 13 was about 23.7 KHz and about 1 Vp-p.

  Then, the vibration displacement of the position of the wire 2 indicated by the arrow in FIG. 6 was measured by a laser Doppler vibration displacement measuring instrument. As a result, about 0.1 μmp-p was measured. Here, it was also confirmed that when the applied voltage was increased, the vibration displacement of the wire 2 increased in proportion to the applied voltage. When the shortest distance between the wire 2 and the magnet 20 was about 2 mm, the vibration displacement was about 1/20 of the shortest distance between the wire 2 and the magnet 20 of about 1 mm. Therefore, it is not desirable that the shortest distance between the wire 2 and the magnet 20 exceeds 2 mm.

  As shown in FIG. 7, when the magnet is removed and the shortest distance between the surface of the front mass 14 of the Langevin type ultrasonic transducer 13 and the wire 2 is about 1 mm, the shortest distance between the wire 2 and the magnet 20 is about 1 mm. On the other hand, the vibration displacement was about 1/10. When the magnet 20 exists in this way, ultrasonic vibration increases. This is considered because the vibration direction of the wire 2 is guided in the direction of the magnet 20 (cutting direction). If this is also used for the general wire saw device 1, the vibration of the wire 2 is guided in the cutting direction, and the vibration in the direction orthogonal to the unnecessary cutting direction is limited.

  However, if the non-cut material is a magnetic material such as ferrite, the wire is magnetized, which is not preferable because the cut powder may adhere to the wire. Therefore, in this case, it is preferable to use a Langevin type ultrasonic transducer from which a magnet is removed.

Further, as shown in the plan view of FIG. 8 and the side view of FIG. 9, in order to bring the wire 2 and the surface to be ultrasonically vibrated closer, a carbon material that is the same material as the base table for fixing the non-cut object is used. It adheres as a proximity plate 18. Then, for example, it is brought into contact with the wire 2 and a dent is created in the carbon as illustrated. Slurry or cutting fluid 11 sprayed from the supply device 10 is stored in this recess. Further, the distance between the wire 2 and the carbon can be easily reduced to 1 mm or less. Moreover, even if the wire 2 and carbon contact directly, there is no possibility of the wire 2 being cut.

  A suitable material for the base is one that has a low cutting resistance and does not damage the wire when cut with a wire. As a material for such a base, there are materials such as glass and plastic in addition to a carbon material. And the material of a base stand is suitable also as a proximity board.

  Next, a method for cutting a sapphire ingot using the wire saw device 1 of the present invention will be described. Here, the wire used what fixed the abrasive grain to the wire surface.

  First, as shown in FIG. 1, a sapphire ingot that is a workpiece 9 is bonded to a base base 8 made of carbon. In addition, a feed unit 7 having a feed motor 6 and feeding an object 9 is provided above the wire row, and the object to be cut bonded to the carbon base 8 of the feed unit 7. The sapphire ingot of No. 9 is pressed against the wire row and polished and cut.

  The wire drive motor 4 is rotated to move the wire array at high speed, and the piezoelectric ceramics 16a and 16b of the Langevin type ultrasonic vibrator 13 to which the magnets shown in FIGS. Apply sonic alternating voltage.

  Then, the supply device 10 whose tip is positioned about 10 mm above the wire 2 is operated to eject the cutting fluid toward the surface of the Langevin type ultrasonic transducer 13. The feed motor 6 is rotated to bring the sapphire ingot into contact with the wire row, cutting is started, and cutting is continued.

  Since the cutting fluid is always supplied to the surface of the magnet 20 whose surface is about 1 mm away from the wire 2, the ultrasonic vibration propagated to the cutting fluid causes the wire 2 to vibrate ultrasonically. Further, since the magnet 20 and the wire 2 are separated from each other by about 1 mm, the wire 2 is not damaged.

  The friction between the wire 2 and the workpiece 9 is reduced by the ultrasonic vibration of the wire 2, so that the wear of the wire 2 is reduced and the risk of cutting the wire 2 is reduced. Furthermore, since the frictional heat between the wire 2 and the workpiece 9 is reduced, the processing accuracy is also improved. Therefore, since the traveling speed of the wire can be improved as compared with the conventional case, the processing efficiency is improved.

  Further, since the cutting fluid is sufficiently supplied between the wire 2 and the workpiece 9 due to the ultrasonic vibration of the wire 2, the cutting speed is improved. Further, since the cutting powder of the workpiece 9 and the consumable powder of the wire 2 are quickly eliminated, the processing accuracy is improved and the cutting speed is also improved.

  Note that ultrasonic cutting is described in detail in Non-Patent Document 1, for example. Ultrasonic cutting has the advantages that the frictional resistance between the workpiece and the tool is reduced, so that the thermal distortion of the machined surface is reduced, the machining accuracy is increased, and the life of the cutting tool is extended. is doing. Further, it is described in detail in Non-Patent Document 2 that the processing speed is doubled or more.

  Furthermore, since the cutting fluid is always supplied to the wire 2 and ultrasonic vibration is added to the cutting fluid, an effect of ultrasonically cleaning the wire is also produced. For this reason, the cutting powder of the workpiece 9 and the consumable powder of the wire 2 are quickly eliminated at the position of the Langevin type ultrasonic transducer 13. This improves the processing accuracy and also improves the cutting speed.

  In the above description, the ultrasonic vibrator is a Langevin type, but for example, a piezoelectric ceramic alone may be used.

  As described above, by applying ultrasonic vibration to the wire, it is possible to provide a highly reliable wire saw device having a long life, high machining accuracy, and high reliability.

DESCRIPTION OF SYMBOLS 1 Wire saw apparatus 2 Wire 3 Multi-groove roller 4 Wire drive motor 5 Bobbin 6 Feed motor 7 Feed unit 8 Base stand 9 Object 10 Feed apparatus 11 Slurry or cutting fluid 12 Electrode plate 13 Ultrasonic vibrator 14 Front mass 15 Rear mass 16 Piezoelectric ceramic 17 Bolt 18 Proximity plate 19 Multi-groove roller 20 Nozzle 21 Water

Claims (4)

In a wire saw apparatus for cutting a workpiece by pressing the workpiece against a traveling wire supplied with a slurry containing loose abrasive grains or a traveling wire with fixed abrasive grains, the wire and an ultrasonic vibrator A slurry or cutting fluid is interposed between the two, and an AC voltage is applied to the ultrasonic transducer. The wire saw device according to claim 1, wherein a slurry or cutting fluid supply device is positioned at a position facing the ultrasonic transducer across a wire. The wire saw device according to claim 1, wherein a slurry or cutting fluid supply device is positioned above the wire and the ultrasonic vibrator is positioned below the wire. The wire saw device according to claim 1, wherein a magnet is joined to the ultrasonic transducer.

Images