Shaping Tool and Methods of Using the Same

Abstract

Disclosed are a shaping tool and a method of using the shaping tool, capable of applying a sufficient compressive stress to a shaping member to prevent an excessively high tensile stress from being imposed on the shaping member so as to achieve an extended usable life even if the shaping member is made of a hard and brittle material. The shaping tool comprises a shaping member, a pressure-applying member surroundingly fitted onto the shaping member, a collet chuck surroundingly fitted onto the pressure-applying member, and a casing surroundingly fitted onto the collet chuck. The pressure-applying member has a plurality of outer peripheral slits and a plurality of inner peripheral slits, which are circumferentially arranged in alternate relation and at even intervals. The collet chuck has an externally-threaded portion at an upper or lower end thereof, and a taper surface formed in an outer peripheral surface thereof to have a diameter which gradually decreases toward the externally-threaded portion. The casing has an inner peripheral surface formed as a taper surface in surface contact with the taper surface. The collet chuck is adapted to be reduced in diameter by fastening a nut disposed above or below the casing to the externally-threaded portion, so as to apply a compressive stress to the shaping member.

1 . A shaping tool comprising:
 a columnar-shaped shaping member having a shaping cavity on an inward side thereof;   a ring-shaped pressure-applying member fitted onto an outer peripheral surface of said shaping member in a surrounding manner;   a ring-shaped collet chuck fitted onto an outer peripheral surface of said pressure-applying member in a surrounding manner; and   a ring-shaped casing fitted onto an outer peripheral surface of said collet chuck in a surrounding manner,   said shaping tool being characterized in that:   said pressure-applying member has a plurality of outer peripheral slits and a plurality of inner peripheral slits, each of said outer peripheral slits being formed to penetrate between a top surface and a bottom surface of said pressure-applying member and extend radially in such a manner as to be opened in the outer peripheral surface of said pressure-applying member, each of said inner peripheral slits being formed to penetrate between the top surface and the bottom surface of said pressure-applying member and extend radially in such a manner as to be opened in an inner peripheral surface of said pressure-applying member, said outer peripheral slits being alternately arranged with respect to said inner peripheral slits along a circumferential direction of said pressure-applying member;   said collet chuck has an externally-threaded portion at an upper or lower end thereof, and a taper surface formed in the outer peripheral surface thereof to have a diameter which gradually decreases toward said externally-threaded portion; and   said casing has an inner peripheral surface formed as a taper surface in surface contact with said taper surface formed in the outer peripheral surface of said collet chuck,   wherein:   said shaping tool includes a nut disposed above or below said casing; and   said collet chuck is adapted to be reduced in diameter by fastening said nut to said externally-threaded portion of said collet chuck.   
   
   
       2 . A shaping tool comprising:
 a columnar-shaped shaping member having a shaping cavity on an inward side thereof;   a ring-shaped pressure-applying member fitted onto an outer peripheral surface of said shaping member in a surrounding manner;   a ring-shaped collet chuck fitted onto an outer peripheral surface of said pressure-applying member in a surrounding manner; and   a ring-shaped casing fitted onto an outer peripheral surface of said collet chuck in a surrounding manner,   said shaping tool being characterized in that:   said pressure-applying member is divided into a plurality of sub-members in a circumferential direction thereof, in such a manner that said sub-members are disposed in a non-contact relation to each other;   said collet chuck has an externally-threaded portion at an upper or lower end thereof, and a taper surface formed in the outer peripheral surface thereof to have a diameter which gradually decreases toward said externally-threaded portion; and   said casing has an inner peripheral surface formed as a taper surface in surface contact with said taper surface formed in the outer peripheral surface of said collet chuck,   wherein:   said shaping tool includes a nut disposed above or below said casing; and   said collet chuck is adapted to be reduced in diameter by fastening said nut to said externally-threaded portion of said collet chuck.   
   
   
       3 . The shaping tool as defined in  claim 1  or  2 , which is designed to satisfy the following relation:
   A1>A2≈A3≈A4   , wherein: A1 is a linear thermal expansion coefficient of said pressure-applying member; A2 is a linear thermal expansion coefficient of said collet chuck; A3 is a linear thermal expansion coefficient of said casing; and A4 is a linear thermal expansion coefficient of said nut.   
   
   
       4 . The shaping tool as defined in any one of  claims 1  or  2 , wherein said nut is disposed above or below said casing while interposing a washer therebetween, wherein said shaping tool is designed to satisfy the following relation:
   A5>A2≈A3≈A4   , wherein: A2 is a linear thermal expansion coefficient of said collet chuck; A3 is a linear thermal expansion coefficient of said casing; A4 is a linear thermal expansion coefficient of said nut; and A5 is a linear thermal expansion coefficient of said washer.   
   
   
       5 . A shaping tool comprising:
 a columnar-shaped shaping member having a shaping cavity on an inward side thereof;   a ring-shaped pressure-applying member fitted onto an outer peripheral surface of said shaping member in a surrounding manner;   a ring-shaped collet chuck fitted onto an outer peripheral surface of said pressure-applying member in a surrounding manner; and   a ring-shaped casing fitted onto an outer peripheral surface of said collet chuck in a surrounding manner,   said shaping tool being characterized in that:   said pressure-applying member has a plurality of outer peripheral slits and a plurality of inner peripheral slits, each of said outer peripheral slits being formed to penetrate between a top surface and a bottom surface of said pressure-applying member and extend radially in such a manner as to be opened in the outer peripheral surface of said pressure-applying member, each of said inner peripheral slits being formed to penetrate between the top surface and the bottom surface of said pressure-applying member and extend radially in such a manner as to be opened in an inner peripheral surface of said pressure-applying member, said outer peripheral slits being alternately arranged with respect to said inner peripheral slits along a circumferential direction of said pressure-applying member;   said casing has an internally-threaded portion in an upper or lower end region of an inner peripheral surface thereof, and a taper surface formed in the inner peripheral surface thereof to have a diameter which gradually increases toward said internally-threaded portion; and   said collet chuck has a taper surface formed in the outer peripheral surface thereof to be in surface contact with said taper surface formed in the inner peripheral surface of said casing,   wherein:   said shaping tool includes a bolt which is disposed above or below said collet chuck; and   said collet chuck is adapted to be reduced in diameter by fastening said bolt to said internally-threaded portion of said casing.   
   
   
       6 . A shaping tool comprising:
 a columnar-shaped shaping member having a shaping cavity on an inward side thereof;   a ring-shaped pressure-applying member fitted onto an outer peripheral surface of said shaping member in a surrounding manner;   a ring-shaped collet chuck fitted onto an outer peripheral surface of said pressure-applying member in a surrounding manner; and   a ring-shaped casing fitted onto an outer peripheral surface of said collet chuck in a surrounding manner,   said shaping tool being characterized in that:   said pressure-applying member is divided into a plurality of sub-members in a circumferential direction thereof, in such a manner that said sub-members are disposed in a non-contact relation to each other;   said casing has an internally-threaded portion in an upper or lower end region of an inner peripheral surface thereof, and a taper surface formed in the inner peripheral surface thereof to have a diameter which gradually increases toward said internally-threaded portion; and   said collet chuck has a taper surface formed in the outer peripheral surface thereof to be in surface contact with said taper surface formed in the inner peripheral surface of said casing,   wherein:   said shaping tool includes a bolt which is disposed above or below said collet chuck; and   said collet chuck is adapted to be reduced in diameter by fastening said bolt to said internally-threaded portion of said casing.   
   
   
       7 . The shaping tool as defined in  claim 5  or  6 , which is designed to satisfy the following relation:
   A1>A2≈A3≈A6   , wherein: A1 is a linear thermal expansion coefficient of said pressure-applying member; A2 is a linear thermal expansion coefficient of said collet chuck; A3 is a linear thermal expansion coefficient of said casing; and A6 is a linear thermal expansion coefficient of said bolt.   
   
   
       8 . The shaping tool as defined in any one of  claims 5  or  6 , wherein said bolt is disposed above or below said collet chuck while interposing a washer therebetween, wherein said shaping tool is designed to satisfy the following relation:
   A5>A2≈A3≈A6   , wherein: A2 is a linear thermal expansion coefficient of said collet chuck; A3 is a linear thermal expansion coefficient of said casing; A6 is a linear thermal expansion coefficient of said bolt; and A5 is a linear thermal expansion coefficient of said washer.   
   
   
       9 . The shaping tool as defined in any one of  claims 1 ,  2 ,  5  or  6 , where said casing has a Young's modulus of 200 GPa or more. 
   
   
       10 . The shaping tool as defined in any one of  claims 1 ,  2 ,  5  or  6 , where said collet chuck has a Young's modulus of 300 GPa or less. 
   
   
       11 . A shaping tool comprising:
 a columnar-shaped shaping member having a shaping cavity on an inward side thereof;   an inner circumferential ring fitted onto an outer peripheral surface of said shaping member in a surrounding manner; and   an outer circumferential ring fitted onto an outer peripheral surface of said inner circumferential ring in a surrounding manner,   said shaping tool being characterized in that said inner circumferential ring is formed as a pressure-applying mechanism section.   
   
   
       12 . The shaping tool as defined in  claim 11 , wherein said pressure-applying mechanism section has a structure with a plurality of outer peripheral slits and a plurality of inner peripheral slits, each of said outer peripheral slits being formed to penetrate between a top surface and a bottom surface of said inner circumferential ring and extend radially in such a manner as to be opened in the outer peripheral surface of said inner circumferential ring, each of said inner peripheral slits being formed to penetrate between the top surface and the bottom surface of said inner circumferential ring and extend radially in such a manner as to be opened in an inner peripheral surface of said inner circumferential ring, said outer peripheral slits being alternately arranged with respect to said inner peripheral slits along a circumferential direction of said inner circumferential ring. 
   
   
       13 . The shaping tool as defined in  claim 11 , wherein said pressure-applying mechanism section has a structure in which said inner circumferential ring is divided into a plurality of sub-members in a circumferential direction thereof, in such a manner that said sub-members are disposed in a non-contact relation to each other. 
   
   
       14 . The shaping tool as defined in any one of  claims 11  to  13 , wherein said pressure-applying mechanism section has a linear thermal expansion coefficient equal to or greater than that of said outer circumferential ring. 
   
   
       15 . The shaping tool as defined in any one of  claims 11  to  13 , where said outer circumferential ring has a Young's modulus of 200 GPa or more. 
   
   
       16 . The shaping tool as defined in any one of  claims 1 ,  2 ,  5 ,  6  or  11 , where said shaping member is made of a hard and brittle material. 
   
   
       17 . The shaping tool as defined in  claim 16 , wherein said hard and brittle material is at least one selected from the group consisting of high-speed steel (HSS), hard metal, cermet, ceramics and diamond. 
   
   
       18 . A shaping method using the shaping tool as defined in any one of  claims 1 ,  2 ,  5 ,  6  or  11 , wherein said shaping tool is used at a temperature greater than room temperature. 
   
   
       19 . The method as defined in  claim 18 , wherein said shaping tool is used in subjecting a metal to plastic working.