Holder, cutting tool, and method for manufacturing machined product
The holder includes a body having a rod shape extending from a first end surface to a second end surface and including a large-diameter portion which is a recess extending from the first end surface, a weight located in the large-diameter portion, a ring-shaped first elastic member, and a lid press-fitted into the large-diameter portion from the side of the first end surface. The inner peripheral surface of the large-diameter portion includes a first region located on the side of the first end surface and a second region located closer to the second end surface than the first region. The first elastic member comes into contact with the inner peripheral surface of the large-diameter portion in the second region to fix the weight to the inner peripheral surface. The surface roughness of the second region is greater than the surface roughness of the first region.
1 . A cutting tool holder configured to receive a cutting insert, wherein the cutting tool holder comprising:
a body having a bar shape extending along a center axis from a first end surface to a second end surface, the body comprising a recess extending from the first end surface toward the second end surface;
a weight located in the recess;
an elastic member having a ring shape in contact with an inner peripheral surface of the recess; and
a lid press-fitted into the recess from a side of the first end surface, wherein
the inner peripheral surface of the recess comprises
a first region located on a side of the first end surface and being in contact with the lid; and
a second region located closer to the second end surface than the first region and being in contact with the elastic member,
the weight is fixed to the inner peripheral surface by the elastic member, and
a surface roughness of the second region is greater than a surface roughness of the first region.
2 . The cutting tool holder according to claim 1 , wherein
the lid comprises an outer peripheral surface configured to come into contact with the first region, and
a surface roughness of the outer peripheral surface is the same as the surface roughness of the first region.
3 . The cutting tool holder according to claim 1 , wherein
the body further comprises an outer surface, and
a surface roughness of the outer surface is equal to or less than the surface roughness of the first region.
4 . The cutting tool holder according to claim 1 , wherein
the second region comprises a groove having a spiral shape extending along the center axis.
5 . The cutting tool holder according to claim 4 , wherein
a depth of the groove is smaller than a dimension of the elastic member in a direction orthogonal to the center axis in a cross section along the center axis.
6 . The cutting tool holder according to claim 1 , wherein
an inner diameter of the recess in the second region is smaller than an inner diameter of the recess in the first region, and wherein
the recess further comprises a step located between the first region and the second region.
7 . A cutting tool comprising:
the cutting tool holder according to claim 1 ; and
a cutting insert located on a side of the first end surface in the holder.
8 . A method for manufacturing a machined product, the method comprising:
rotating a workpiece;
bringing a cutting tool into contact with the workpiece that is rotating, wherein the cutting tool comprises a cutting tool holder and a cutting insert, and the cutting tool holder comprises:
a body having a bar shape extending along a center axis from a first end surface to a second end surface, the body comprising a recess extending from the first end surface toward the second end surface;
a weight located in the recess;
an elastic member having a ring shape in contact with an inner peripheral surface of the recess; and
a lid press-fitted into the recess from a side of the first end surface, wherein
the inner peripheral surface of the recess comprises
a first region located on a side of the first end surface and being in contact with the lid; and
a second region located closer to the second end surface than the first region and being in contact with the elastic member,
the weight is fixed to the inner peripheral surface by the elastic member and
a surface roughness of the second region is greater than a surface roughness of the first region; and
separating the cutting tool from the workpiece.