US-12617025-B2 - Holder, cutting tool, and method for manufacturing machined product

US12617025B2US 12617025 B2US12617025 B2US 12617025B2US-12617025-B2

Abstract

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.

Inventors

Tomohito Shuto
Yoshihito IKEDA
Hirotoshi GONZUI

Assignees

KYOCERA CORPORATION

Dates

Publication Date: 20260505
Application Date: 20220407
Priority Date: 20210507

Claims (8)

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.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is national stage application of International Application No. PCT/JP2022/017229, filed on Apr. 7, 2022, which claims priority to Japanese Patent Application No. 2021-079248, filed on May 7, 2021. TECHNICAL FIELD The present disclosure relates to a holder for a cutting tool used when machining workpieces such as those made of metal, a cutting tool, and a method for manufacturing a machined product. BACKGROUND OF INVENTION For example, a cutting tool described in Patent Document 1 is known as a cutting tool used when machining workpieces such as those made of metal. The cutting tool described in Patent Document 1 includes a holder and a cutting insert. The holder includes a stem including a cavity, a weight that is a damping member inserted into the cavity, an O-ring positioned between the stem and the weight, and a head that closes an inlet of the cavity. A cutting insert including a cutting edge is mounted on a distal end portion of the head. When a protrusion amount L of a distal end portion of the cutting edge from an end surface of the stem is increased with respect to a diameter D of the stem, vibration of the stem in a radial direction is easily generated in the holder, and machining accuracy deteriorates, since the rigidity of the stem made of steel is low. The vibration of the holder can be reduced by accommodating a weight having a natural frequency different from that of the stem in the stem and vibrating the stem and the weight at different frequencies. CITATION LIST Patent Literature Patent Document 1: WO2020/049167 SUMMARY A holder according to a non-limiting example of the present disclosure includes: a body having a bar shape extending along a center axis from a first end surface to a second end surface, the body including a recessed portion extending from the first end surface toward the second end surface; a weight located in the recessed portion; an elastic member having a ring shape in contact with an inner peripheral surface of the recessed portion; and a lid press-fitted to the recessed portion from a side of the first end surface. The inner peripheral surface of the recessed portion includes: a first region located on a side of the first end surface and with which the lid can come into contact; and a second region located closer to the second end surface than the first region and with which the elastic member can come into contact. The elastic member comes into contact with the inner peripheral surface in the second region and fixes the weight to the inner peripheral surface. A surface roughness of the second region is greater than a surface roughness of the first region. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view illustrating a cutting tool of a non-limiting embodiment of the present disclosure. FIG. 2 is a plan view of the cutting tool illustrated in FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III indicated by arrows in FIG. 2. FIG. 4 is an enlarged view of a first end surface side in FIG. 3. FIG. 5 is an enlarged view of a second end surface side in FIG. 3. FIG. 6 is an enlarged view of a second end surface side of a holder according to a first variation. FIG. 7 is an enlarged view of a first end surface side of a holder according to a second variation. FIG. 8 is a schematic diagram illustrating a process of a method for manufacturing a machined product of a non-limiting example. FIG. 9 is a schematic diagram illustrating a process of the method for manufacturing a machined product of the non-limiting example. FIG. 10 is a schematic diagram illustrating a process of the method for manufacturing a machined product of the non-limiting example. DESCRIPTION OF EMBODIMENTS Detailed description will be given below of the holder, the cutting tool, and the method for manufacturing a machined product of an embodiment that is an example of the present disclosure with reference to the diagrams. However, each of the figures, which will be referred to below, is a simplified representation of only main members necessary for description of the embodiments. Thus, the holder and the cutting tool may include any constituent member not illustrated in each of the figures referenced. The dimensions of the members in the drawings do not faithfully represent the actual dimensions of the constituent members, the dimension ratios of the members, or the like. Cutting Tool FIG. 1 is a perspective view illustrating a cutting tool 10 according to a first embodiment. FIG. 2 is a plan view illustrating the cutting tool 10. The cutting tool 10 is a tool in which a head 2 is mounted to a distal end side of a round bar-shaped holder 1 extending in an X-axis direction in FIG. 1. A cutting insert (hereinafter referred to as an insert) 3 is mounted on the head 2. The cutting tool 10 is, for example, a turning tool, and specific examples thereof include a tool for external turning, a tool for boring, a tool for groove-forming,