Apparatus for cutting vitreous silica crucible

Abstract

A cutting method and an apparatus are provided which enable a rim area or other part of a vitreous silica crucible to be cut off so as to leave a smooth cut surface without damaging the cut edge, etc. The apparatus for cutting the crucible comprises a disk-shaped cutting blade (10) disposed to be movable with respect to the crucible. Without rotating the crucible (20), the rotating cutting blade (10) is brought into contact with a surface of the crucible wall and pushed forward in the wall thickness direction to make a cut piercing the crucible wall. The cutting blade (10) is moved relatively to the crucible (20) in the circumferential direction of the crucible (20) while keeping the cutting blade in the state of piercing the wall. A rim area (25) of the crucible (20) is thus cut off.

Claims

1. An apparatus for cutting a vitreous silica crucible, comprising: a disk-shaped cutting blade configured to cut the vitreous silica crucible; a first support; a pair of inner arms, each inner arm having a proximal end and a distal end defining a vertical length of the respective inner arm, each inner arm attached to the first support at the proximal end and extending in a first vertical direction away from the first support; a cushion on the distal end of each inner arm, each cushion having an outwardly facing contact surface, each outwardly facing contact surface having a vertical length that is less than the vertical length of the respective inner arm and each cushion being spaced from the first support by a vertical distance that is greater than the vertical length of the respective outwardly facing contact surface, each outwardly facing contact surface configured to engage an inner side of a wall of the crucible; a second support; and a pair of outer arms attached to the second support, each outer arm extending from the second support in a second vertical direction that is opposite the first vertical direction, each outer arm configured to engage an outer side of the wall of the crucible; wherein the cutting blade is a rotatable cutting blade translatable substantially horizontally toward and away from a center vertical axis of the first support for contacting a surface of the crucible wall and pushing through the crucible wall for making a cut that penetrates the crucible wall, and wherein, upon the translation of the cutting blade through the crucible wall, a rim area of the crucible can be cut off by relatively moving the cutting blade with respect to the crucible in the circumferential direction of the crucible while the cutting blade keeps penetrating the wall; and wherein the inner arms are configured to hold the cut off rim area of the crucible.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is an explanatory view illustrating a cutting method in accordance with an exemplary embodiment;

(2) FIG. 2 is an explanatory view illustrating a cutting method in accordance with the present invention;

(3) FIG. 3 is an explanatory view illustrating a cutting method in accordance with the present invention;

(4) FIG. 4 is a schematic view illustrating a cutting apparatus in accordance with the present invention;

(5) FIG. 5 is a schematic view illustrating a cutting apparatus in accordance with another exemplary embodiment;

(6) FIG. 6 is an explanatory view illustrating a related art cutting method; and

(7) FIG. 7 is an explanatory view illustrating a related art cutting method.

EXPLANATION OF REFERENCE SYMBOL

(8) 10cutting blade, 11supporting means, 12support, 13supporting means, 14arm, 15cushioning member, 16rotational axis, 17arm, 18cushioning member, 20crucible, 21outer surface, 22inner surface, 23burr, 24defect, 25rim area, 27groove, 28cutting groove, 30cut

Best Embodiment for Carrying Out the Invention

(9) Hereinafter, the present invention will be described in detail based on exemplary embodiments.

(10) FIGS. 1 through 3 are explanatory views schematically illustrating a method for cutting a vitreous silica crucible in accordance with the present invention.

(11) In the cutting method of the exemplary embodiment, as illustrated in FIG. 1, a cut 30 penetrating a wall of a crucible 20 is formed by bringing a cutting blade 10, which is rotating, into contact with a surface (outer surface 21 in an example of FIG. 1) of the crucible wall, and by pushing forward the cutting blade 10 in the wall's thickness direction (toward an inside of the crucible) while the crucible 20 is not rotating. Therefore, as illustrated in FIG. 1, the cutting blade 10 penetrates the wall of the crucible 20, and appears at the inner surface of the crucible 20.

(12) Thereafter, as illustrated in FIG. 2, the cutting blade 10 relatively moves with respect to the crucible 20 in the circumferential direction of the crucible 20 by rotating the crucible 20, while the cutting blade 10 keeps penetrating the wall of the crucible 20. As the crucible makes one rotation such that the cut part (cut) 30 extends in the circumferential direction of the crucible 20 with the total thickness of the wall part being penetrated by the cutting blade, a rim area 25 is at last cut off when the cut part (cut) 30 extends around the entire circumference of the crucible 20.

(13) According to the cutting method above, since the cut part extends in the circumferential direction of the crucible 20 in the state where the total thickness of the wall part is cut off, the load of the cut rim area 25 does not concentrate on the inner surface immediately before cut off. Accordingly, the formation of burrs or defects at a cut edge can be substantially reduced. Also, in the cutting method of the exemplary embodiment, the cut 30 penetrating the wall may be formed by bringing the cutting blade 10 into contact with the inner surface of the crucible 20 and by moving the cutting blade 10 toward the outer surface.

(14) According to another cutting method of the present invention, as illustrated in FIG. 3, a shallow groove 27 extending around the entire circumference of the crucible 20 is formed on either of the outer surface or inner surface of the crucible 20, and the rim area of the crucible is cut off by moving the cutting blade 10 toward the groove 27 from the surface opposite to the surface where the groove 27 is formed. The depth of the groove 27 may be in the range of about 1 mm to about 3 mm. The width of the groove 27 may be 0.5 to 2 times the width of the cutting blade 10, and preferably 1 to 2 times the width of the cutting blade 10. The cutting blade 10 used to form the cut 30 penetrating the wall may be used for forming the groove 27, and in this case, the width of the groove 27 is approximately equal to the width of the cut 30. According to this cutting method, a cutting end portion is positioned inside the groove 27 because the cutting blade 10 is moved toward the groove 27 from the surface opposite to the surface where the groove 27 is formed. Therefore, burrs and defects are not formed on the crucible surface.

(15) FIG. 4 schematically illustrates a cutting apparatus in accordance with the present invention. The cutting apparatus shown in FIG. 4 includes a disk-shaped cutting blade 10 disposed sideways with respect to a crucible 20, and a supporting means 11 of the cutting blade 10. A cutting-blade moving means (not shown) for moving the cutting blade 10 in a circumferential direction of the crucible 20 is installed at the supporting means 11.

(16) The cutting apparatus further includes a rotatable support 12 where the crucible 20 is installed, the support 12, on which a pair of arms 17 are installed, is coupled to a rotating means (not shown) with a rotational axis 16 interposed therebetween. At a side of the support 12, the supporting means 11 is installed. In an example illustrated in FIG. 4, the crucible 20 is installed on the support 12 such that an opening of the crucible 20 faces upward.

(17) Over the crucible 20, an elevatable supporting means 13 is installed. The supporting means 13 includes a pair of arms 14 extending downward, and the pair of arms 14 are formed such that they can be opened and closed left and right when viewed in FIG. 4. At a lower end of the arm 14, a cushioning member 15 is installed.

(18) The installation and take-out of the crucible is mechanically performed by the supporting means 13. The arms 14 of the supporting means 13 support the crucible 20 by moving the arms 14 above the crucible 20 installed facing upward, allowing the arms 14 to descend toward the inside of the opening of the crucible, and opening both of the arms 14 to press the cushioning member 15 onto the inner surface of the crucible. In this state, the supporting means 13 moves to an upper region of the support 12 and the arms 14 then descend, so that the crucible 20 is installed on the support 12.

(19) In the cutting apparatus of FIG. 4, after cutting the rim area of the crucible 20 is installed facing upward, the supporting means 13 ascends while keeping the state of supporting the rim area 25, then moves sideways, and thereafter the rim area 25 is taken out to the outside. Afterwards, the supporting means 13 returns to a position above of the crucible 20, and then the arms 14 descend toward the inside of the crucible 20. After that, the supporting means 13 supports the crucible 20 by opening the arms 14 left and right, bringing the cushioning members 15 into contact with the inside of the crucible 20, and by pushing forward the cushioning members 15. In this state, the supporting means 13 ascends, then moves sideways, and the crucible 20 is taken out to the outside.

(20) FIG. 5 illustrates an apparatus for cutting the rim area of the crucible 20 installed facing downward. In the cutting apparatus of FIG. 5, a rotatable support 12 where the crucible 20 is installed is provided. The support 12 is coupled to a rotating means (not shown) with a rotational axis 16 interposed therebetween. On the surface of the support 12, a pair of arms 17 extending toward the inside of the crucible 20 are installed, and a cushioning member 18 is installed at an upper end of each arm 17. The arms 17 are formed such that they can be opened and closed left and right when viewed in FIG. 5. The arms 17 are inserted into the inside of the crucible 20 and opened left and right to press the cushioning members 18 onto the rim area 25, thereby supporting the rim area 25 from the inside thereof.

(21) Over the crucible 20, an elevatable supporting means 13 is installed. The supporting means 13 includes a pair of arms 14 extending toward a lower region from an outer side of the crucible, and the pair of arms 14 are formed such that they can be opened and closed left and right when viewed in FIG. 5. At a lower end of each arm 14, a cushioning member 15 is installed.

(22) At a side of the supporting means 13, a disk-shaped rotating blade 10 is installed. The rotating blade 10 is disposed sideways with respect to the crucible 20, and rotatably supported by a supporting means 11. A means (not shown) for moving the cutting blade 10 back and forth with respect to the crucible 20 is installed at the supporting means 11.

(23) In accordance with the cutting apparatus of FIG. 5, during the cutting of the rim area, the crucible 20 is supported by the supporting means 13 in the state that the crucible faces downward, and the rim area 25 is supported by the arm 17. After cutting the rim area 25, the supporting means 13 ascends while keeping the state of supporting the crucible 20, then moves sideways, and thereafter the crucible 20 is taken out to the outside. While the crucible 20 is being taken out, the cut rim area 25 is supported by the arm 17. Thereafter, the supporting means 13 returns to the upper region of the rim area 25, and then the arm 14 descends to support the rim area 25 by opening the arms 14 left and right, bringing the cushioning members 15 into contact with the inside of the rim area 25, and pushing forward the cushioning members 15. In this state, the supporting means 13 ascends, then moves sideways, and the cut rim area 25 is taken out to the outside.

(24) In both of the cutting apparatuses of FIGS. 4 and 5, the cut penetrating the wall is formed first without rotating the crucible 20, and the cutting blade is then relatively moved with respect to the crucible 20 in the circumferential direction by rotating the crucible 20 while the cutting blade keeps penetrating the wall. Thus, the rim area 25 is cut off.

(25) In specific, the cut penetrating the wall of the crucible 20 is formed by bringing the cutting blade 10 which is rotating into contact with the surface (outer surface) of the crucible wall, and moving the cutting blade in the wall's thickness direction. Thereafter, the operations of the rotating blade 10 and the support 12 are controlled such that the crucible is rotated to relatively move the cutting blade 10 with respect to the crucible 20 in the circumferential direction while the cutting blade keeps penetrating the wall. As the crucible 20 makes one rotation, the cutting blade 10 accordingly moves around the entire circumference of the crucible while the blade keeps penetrating the wall, and resultantly the rim area 25 is cut off.

(26) Since the crucible is installed facing upward in the cutting apparatus of FIG. 4, a supporting means at a lower side is not necessary, the apparatus can be simplified and the cut rim area hung by the supporting means can be taken to the outside as it is. Meanwhile, in the cutting apparatus of FIG. 5 where the crucible 20 is installed facing downward, lubricating water which is supplied during the cutting operation does not remain inside the crucible so that the crucible is not contaminated.