JP2008178938A - Wire saw - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wire saw capable of assuring bead retaining strength of a wire while reducing a diameter. <P>SOLUTION: The wire saw 1 is an endless wire saw including cylindrical beads 5 consisting of super-abrasive grains 13 fixed to the outer periphery of a shank 11 which are arranged on the wire 3. In the wire saw 1, the diameter R of the bead 5 is 0.8 mm≤ and ≤5.0 mm, and a relation between a bead length L in the extending direction A of the wire 3 and a bead arrangement pitch P is 0.35<L/P<0.72. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an endless wire saw in which cylindrical beads formed by superabrasive grains fixed to the outer periphery of a shank are arranged on a wire.

Conventionally, a wire saw in which grinding members are arranged on a wire at a predetermined interval is known (see, for example, Patent Document 1). This type of wire saw is used for cutting concrete, stone, and the like, taking advantage of the fact that the cutting speed is fast and it can handle a large cross section. As a grinding member of a wire saw described in Patent Document 1, beads in which diamond abrasive grains are fixed to the outer periphery of a shank having a diameter of about 10 mm are used.
JP 2000-61929 A

  For example, such a wire saw may be applied to cutting a workpiece made of an expensive material. In that case, it is desired to reduce the diameter of the wire saw itself in order to reduce the material loss of the workpiece. However, if the size of the entire wire saw is reduced as it is to reduce the diameter, the contact area between the beads and the wires decreases, and the fixing strength of the beads to the wires decreases. There is a risk of misalignment on the top or beads turning around the wire.

  Then, an object of this invention is to provide the wire saw which can ensure the fixed intensity | strength of the bead with respect to a wire, achieving diameter reduction.

  The wire saw according to the present invention is an endless wire saw in which cylindrical beads formed by superabrasive grains fixed to the outer periphery of a shank are arranged on a wire. The bead diameter R is 0.8 mm or more and 5.0 mm. The relationship between the bead length L in the wire extending direction and the bead arrangement pitch P is 0.35 <L / P <0.72.

  Since this wire saw is reduced in diameter so that the diameter of the beads is 0.8 mm or more and 5.0 mm or less, kerf loss is reduced and material loss of the workpiece to be cut can be suppressed. Moreover, since the bead length L is larger than 0.35 times the arrangement pitch P, the contact area between the bead and the wire can be secured, and as a result, the fixing strength of the bead to the wire can be secured. . In general, if the bead length L is too long with respect to the arrangement pitch P, the wire saw is difficult to bend, but the bead length L is suppressed to be less than 0.72 times the arrangement pitch P. The wire saw can be easily bent, and as a result, when the wire saw is bent and traveled, the wire saw can be smoothly traveled.

  Further, the wire saw according to the present invention includes a covering portion that covers the outer periphery of the wire between the beads, and the boundary between the bead shank and the covering portion is formed obliquely with respect to the extending direction of the wire. Is preferred. According to such a configuration, since the rotation of the beads around the wire is regulated by the covering portion, the beads are difficult to rotate around the wire, and the fixing strength of the beads in the rotation direction with respect to the wire can be improved. .

  The wire saw according to the present invention preferably includes a coil spring wound around the outer periphery of the wire between the beads. According to such a configuration, since the positional relationship between adjacent beads is regulated by the biasing force of the coil spring, it becomes difficult for the beads to move in the extending direction of the wire, and as a result, the fixing strength of the beads to the wire is improved. can do.

  According to the wire saw of the present invention, it is possible to secure the fixing strength of the beads to the wire while achieving a reduction in diameter.

  Hereinafter, preferred embodiments of a wire saw according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
A wire saw 1 shown in FIGS. 1 and 2 is a wire saw in which beads 5 for a wire saw as a grinding member are arranged and fixed to a wire 3 at equal intervals. Hereinafter, in this wire saw 1, the length of the beads 5 in the extending direction A of the wires 3 is L, and the arrangement pitch of the beads 5 is P. In the wire saw 1, a stranded wire 3 is inserted into a hole 5a of a metal bead 5, and the bead 5 is bonded to the wire 3 using an adhesive. Further, the exposed portion of the wire 3 between the adjacent beads 5 is covered with a cylindrical covering portion 7 made of rubber formed by plating. In addition, you may use the thing made from resin as the coating | coated part 7. FIG. Since this wire saw 1 has an endless shape in which both ends of the wire 3 are connected by weaving, it can be applied to a cutting machine using such an endless wire saw.

  The beads 5 have a cylindrical stainless steel shank 11, and diamond abrasive grains (super abrasive grains) 13 are fixed to the central portion of the outer periphery of the shank 11 by brazing. Thus, since the superabrasive grains are directly fixed to the outer periphery of the shank 11 using brazing, the diameter of the beads 5 can be kept small. In this case, the diamond abrasive grains 13 may be regularly arranged on the outer peripheral surface of the shank 11 or may be randomly arranged.

In order to reduce kerf loss, this wire saw 1 has a diameter R of beads 5
0.8 mm ≦ R ≦ 5.0 mm (1)
Among these, the diameter R is more preferably 0.8 mm or more and 4.0 mm or less. If the beads 5 having such a size are used, the wire saw 1 is smaller in diameter than the conventional wire saw (bead diameter is about 1.0 to 1.5 mm). It can be suppressed to a small value of about ~ 1.8 mm, and the material loss of the workpiece can be reduced. In particular, it is more preferable to reduce the diameter R of the beads 5 to 4.0 mm or less because kerf loss can be suppressed to a level comparable to a general band saw (thickness of about 3 mm). As a result, it is possible to cut an expensive work such as ceramic, quartz glass, and silicon, which has been conventionally cut using a band saw, using the wire saw 1. In this case, taking advantage of the characteristics of the wire saw, it is possible to cope with a workpiece having a larger cross section than when a band saw is used, and the cutting speed is also improved.

  On the other hand, when the diameter of the bead 5 is reduced, the contact area between the inner wall of the bead hole 5a and the wire 3 is reduced, and it is difficult to process the inner wall of the small bead hole 5a for improving the adhesive strength. Therefore, it becomes difficult to secure the fixing strength of the bead 5 to the wire 3. If the fixing strength of the bead 5 to the wire 3 is insufficient, the bead 5 may be displaced on the wire 3 or the bead 5 may be rotated around the wire 3 when the wire saw 1 is used.

Therefore, in this wire saw 1, the relationship between the bead length L of the beads 5 and the arrangement pitch P is
0.35 <L / P <0.72 Formula (2)
It is preferable to set so as to satisfy. As shown in the figure, in this bead 5, the bead length L is equal to the length of the shank 11. Thus, by setting the bead length L to be relatively long so as to exceed 0.35 times the arrangement pitch P, the bonding area between the inner wall of the bead hole 5a and the wire 3 can be secured. 5 can be secured to the wire 3. As a result, it is possible to prevent the position of the bead 5 from shifting in the extending direction of the wire 3 or rotating around the wire 3 while the wire saw 1 is in use. Further, by making the bead length L smaller than 0.72 times the arrangement pitch P, the wire saw 1 can be bent with a relatively small radius of curvature without becoming excessively large with respect to the pitch P. As a result, even when the wire saw 1 travels on a curved track, the wire saw 1 can be easily wound around the pulley and smoothly traveled. It is more preferable that the relationship between the bead length L of the beads 5 and the arrangement pitch P is set so as to satisfy 0.44 ≦ L / P ≦ 0.50.

  Further, as a wire saw that facilitates the reduction in diameter, there is a type of wire saw in which abrasive grains are directly fixed to the wire surface. Compared to such a type, the wire saw 1 using the beads 5 has a breaking strength. Is excellent at a high point. In addition, there is a type of bead in which an abrasive layer containing diamond abrasive grains is pre-sintered and fixed to the outer periphery of the shank, but in this type, the abrasive layer becomes too thin and easily breaks, so the diameter is reduced. Is not easy.

  Subsequently, a cutting test performed by the present inventors using the wire saw 1 will be described.

  The details of the wire saw 1 used for the cutting test are as follows. The wire 3 for the wire saw 1 is a 7 × 7 twist outer diameter of 2.0 mm. The beads 5 are arranged on the wire 3 at equal intervals of the arrangement pitch P and fixed with an adhesive for metal bonding. As the shank 11 of this bead 5, a SUS403-made one having an inner diameter of 2.2 mm, an outer diameter of 3.2 mm, and a length of 11 mm is used. The grains 13 are randomly arranged and fixed by brazing. The range where the diamond abrasive grains 13 are fixed extends over a length of 5.0 mm at the central portion of the outer peripheral surface of the shank 11. Moreover, the diameter of the coating | coated part 7 is 3.8 mm. The bead diameter R is larger than the diameter of the shank 11 by the thickness of the brazed diamond abrasive grains 13, and the diameter R = 4.0 mm. The bead length L is equal to the length of the shank 11.

Using each of the test wire saws T1 to T5 in which the bead length L and the arrangement pitch P of the wire saw 1 were variously changed, quartz glass and silicon, which are precision works, were cut at a cutting surface of 1 m ² . At this time, the peripheral speed was 1300-1800 m / min, and the cutting speed was about 5 mm / min. The results of this cutting test are shown in Table 1 below.

  The bead retention strength in the table means the adhesion strength of the bead 5 to the wire 3 and is a value obtained by measuring the shear strength of the adhesion surface of the bead 5 to the wire 3.

  As shown in Table 1, since the wire saws T1 and T2 were reduced in diameter so as to satisfy the above formula (1), the precision work could be cut with a kerf loss of about 4.3 mm. Moreover, since the bead length L and the array pitch P are set so that the wire saws T1 and T2 satisfy the above mathematical formula (2), the wire saws T1 and T2 can smoothly travel on the curved track. Further, the bead holding strength can be sufficiently secured to be 1.20 kN for the wire saw T1 and 0.8 kN for the wire saw T1, and the phenomenon that the beads 5 are displaced or rotated on the wire 3 even after the workpiece is cut. I couldn't see it.

  Further, the bead length L and the array pitch P of the wire saw T3 do not satisfy the above formula (2), but the bead holding strength is increased by further crimping the beads 5 bonded to the wire 3, and the same bead holding strength as the wire saw T2 Is realized. Even with such a wire saw T3, the deviation or rotation of the beads 5 after the workpiece was cut was not observed. From this result, it was found that a value not less than 0.17 times the bead diameter R (unit: mm) was required as the bead holding strength (unit: kN) in order to prevent the deviation and rotation of the beads 5. . It has been found that the wire saws T1 and T2 can satisfy such bead holding strength by using only an adhesive, and can prevent the bead 5 from being displaced or rotated.

  In comparison, the wire saw T4 has a bead length L that is too small with respect to the arrangement pitch P, so that the holding strength of the bead 5 with respect to the wire 1 is relatively weak at 0.3 kN, and the deviation of the bead 5 on the wire 3 is relatively small. Or rotation occurred. The wire saw T5 has an arrangement pitch P of 25 mm, a bead length L of 18 mm, and a length of the covering portion 7 of 7 mm. Thus, since the bead length L was too large with respect to the arrangement pitch P, the wire 1 was difficult to bend and the curved track could not be smoothly run.

  From the above results, by setting the bead length L and the array pitch P so as to satisfy the above formula (2), the wire saw 1 can be smoothly run along the curved path, and even after cutting the workpiece, It has been found that the beads 5 fixed with the adhesive can be prevented from shifting or rotating on the wire 3.

(Second Embodiment)
Next, a wire saw 51 shown in FIGS. 3 and 4 will be described as a second embodiment of the wire saw according to the present invention. In addition, in this wire saw 51, about the structure same or equivalent to the wire saw 1, the same code | symbol is attached | subjected to drawing and the description is abbreviate | omitted.

  The wire saw 51 includes a bead 55 instead of the bead 5 in the wire saw 1 described above, and a covering portion 57 instead of the covering portion 7. This bead 55 is different from the bead 5 having the cylindrical shank 11 in that it has a shank 61 having an oblique cylindrical shape. Corresponding to the shape of the beads 55, the covering portion 57 is also different from the cylindrical covering portion 7 in that it forms an oblique cylindrical shape. Therefore, unlike the wire saw 1, the boundary between the bead 55 and the covering portion 57 in the wire saw 51 is formed obliquely with respect to the extending direction A of the wire 3. According to such a configuration, the rotation of the bead 55 around the wire 3 is restricted by the covering portion 57, so that the bead 55 is difficult to rotate around the wire 3, and the fixing strength of the bead 55 in the rotation direction is improved. . As a result, the bead 55 is further suppressed from rotating around the wire 3.

(Third embodiment)
A wire saw 51 shown in FIG. 5 will be described as a third embodiment of the wire saw according to the present invention. In addition, in this wire saw 51, about the structure same or equivalent to the wire saw 1, the same code | symbol is attached | subjected to drawing and the description is abbreviate | omitted.

  The wire saw 71 is further provided with a coil spring 72 mounted between all the beads 5 and disposed between the wire 3 and the covering portion 7. The coil spring 72 is wound around the outer peripheral surface of the wire 3 and is compressed by being sandwiched between end surfaces of adjacent beads 5. The covering portion 7 covers the wire 3 while covering the coil spring 72 from the outside. According to such a configuration, the positional relationship between the adjacent beads 5 is regulated by the biasing force of the coil spring 72, so that the beads 5 are difficult to move in the extending direction A of the wire 3, and the beads 5 in the direction A Fixing strength is improved. As a result, the displacement of the position of the bead 5 in the extending direction A of the wire 3 is further suppressed.

  In manufacturing the endless wire saw 71, it is necessary to braid and connect both ends of the wire 3, and the connection portion needs to be fitted with a coil spring 72 after the connection. Therefore, if a coil spring 72 having an open-ended end shape is employed, after the ends of the wire 3 are knitted and connected, the coil spring 72 can be easily wound around the wire 3 in the connecting portion. .

  The present invention is not limited to the embodiment described above. For example, in the beads 5 and 55 described above, the method for fixing the diamond abrasive grains 13 to the outer periphery of the shank 11 is not limited to the brazing method, and an electrodeposition method may be used. The diamond abrasive grains 13 are not limited to a single layer and may be fixed in multiple layers. Moreover, you may form a diamond abrasive grain layer in the outer periphery of the shank 11 by the imprint method. Further, the superabrasive grains fixed to the outer periphery of the shank 11 are not limited to diamond abrasive grains, and CBN abrasive grains may be used.

It is a partially broken perspective view which shows 1st Embodiment of the wire saw which concerns on this invention. It is sectional drawing of the wire saw shown in FIG. It is a fragmentary sectional view which shows 2nd Embodiment of the wire saw which concerns on this invention. It is a disassembled perspective view of the wire saw shown in FIG. It is a partially broken perspective view which shows 3rd Embodiment of the wire saw which concerns on this invention. It is sectional drawing of the wire saw shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,51,71 ... Wire saw, 3 ... Wire, 5,55 ... Bead, 7, 57 ... Covering part, 11, 61 ... Shank, 13 ... Diamond abrasive grain (superabrasive grain), 72 ... Coil spring, A ... Of wire Extension direction, L ... bead length, P ... arrangement pitch, R ... bead diameter.

Claims (3)

In an endless wire saw in which cylindrical beads formed by superabrasive grains fixed to the outer periphery of the shank are arranged in a wire,
The diameter R of the beads is 0.8 mm or more and 5.0 mm or less,
The relationship between the length L of the beads in the extending direction of the wires and the array pitch P of the beads is:
0.35 <L / P <0.72
The wire saw characterized by being. A covering portion covering the outer periphery of the wire between the beads,
The wire saw according to claim 1, wherein a boundary between the shank of the bead and the covering portion is formed obliquely with respect to an extending direction of the wire.   The wire saw according to claim 1 or 2, further comprising a coil spring wound around an outer periphery of the wire between the beads.

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