INSERT TYPE CUTTING INSTRUMENT AND INSERT, METHOD FOR ATTACHING INSERT TO INSERT MAIN BODY

Abstract

This insert type cutting instrument includes: an insert formed as a flat polygonal plate, and which has an upper surface formed as a rake surface and a lower surface; an instrument main body which has a recessed portion formed on an outer side surface of a head portion of the instrument main body; and an insert seat formed on a wall surface of the recessed portion facing in a normal rotation direction of the instrument main body, and to which the insert is attached so that the upper surface of the insert faces in the normal rotation direction of the instrument main body. A first through-hole and a second through-hole are formed in the insert. A first screw hole and a second screw hole are formed in the insert seat of the instrument main body so that the first screw hole separates from the second screw hole in an axial direction of the instrument main body. The insert is mounted on the insert seat so that the center of the first screw hole is located closer to the axis than the center of the first through-hole and is located closer to a base end of the instrument main body than the center of the first through-hole, and the center of the second screw hole is located closer to the axis than a center of the second through-hole and is located closer to the base end of the instrument main body than the center of the second through-hole. A degree θ1 of a first inclination angle formed by the intersection of a straight line passing through the center of the first screw hole and the center of the first through-hole with the axis is equal to or less than a degree θ2 of a second inclination angle formed by the intersection of a straight line passing through the center of the second screw hole and the center of the second through-hole with the axis.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an embodiment of an insert type cutting instrument of the present invention.

FIG. 2 is a side plan view showing the embodiment of the insert type cutting instrument of the present invention.

FIG. 3 is a view showing the embodiment of the insert type cutting instrument of the present invention, and shows a side plan view of the insert type cutting instrument viewed from a direction of an arrow in FIG. 2.

FIG. 4 is a view showing the embodiment of the insert type cutting instrument of the present invention, and shows a enlarged view of an insert seat and around thereof.

FIG. 5 is a view showing the embodiment of the insert type cutting instrument of the present invention, and shows a sectional view taken along a T-T line in FIG. 4.

FIG. 6 is a view showing the embodiment of the insert type cutting instrument of the present invention, and shows a sectional view taken along a U-U line in FIG. 4.

FIG. 7 is a view showing the embodiment of the insert type cutting instrument of the present invention, and shows a sectional view of the insert type cutting instrument taken along a V-V line in FIG. 6.

FIG. 8 is a plan view showing a condition in which a second through-hole of the insert contacts a second clamping screw screwed into a second screw hole of the instrument main body.

FIG. 9 is a view showing the embodiment of the insert type cutting instrument of the present invention, and shows the instrument main body which forms the insert type cutting instrument.

FIG. 10 is a view showing the embodiment of the insert type cutting instrument of the present invention, and shows a perspective view of the insert attached to the instrument main body shown in FIG. 9 and which forms the insert type cutting instrument.

FIG. 11 is a view showing the embodiment of the insert type cutting instrument of the present invention, and shows a perspective view of the insert in FIG. 10 viewed from the lower side of the insert.

FIG. 12 is a view showing the embodiment of the insert type cutting instrument of the present invention, and shows a side plan view of the insert in FIG. 10 viewed from the lower side of the insert.

Claims

1. An insert type cutting instrument, comprising: an insert formed as a flat polygonal plate, and which has an upper surface formed as a rake surface and a lower surface facing opposite the upper surface;an instrument main body allowed to rotate centering around an axis, and which has a recessed portion formed on an outer side surface of a head portion of the instrument main body; andan insert seat formed on a wall surface of the recessed portion facing in a normal rotation direction of the instrument main body, and to which the insert is attached so that the lower surface of the insert contacts the insert seat and the upper surface of the insert faces in the normal rotation direction of the instrument main body; whereina first through-hole which goes through the upper surface of the insert and the lower surface, and a second through-hole which goes through the upper surface and the lower surface and which is located closer to a tip of the instrument main body than the first through-hole when the insert is mounted on the insert seat are formed in the insert,a first screw hole and a second screw hole located closer to the tip of the instrument main body than the first screw hole are formed in the insert seat of the instrument main body so that the first screw hole separates from the second screw hole in the axial direction,the insert is mounted on the insert seat so that the center of the first screw hole is located closer to the axis of the instrument main body than the center of the first through-hole and is located closer to a base end of the instrument main body than the center of the first through-hole, and the center of the second screw hole is located closer to the axis of the instrument main body than a center of the second through-hole and is located closer to the base end of the instrument main body than the center of the second through-hole, anda degree θ1 of a first inclination angle formed by the intersection of a straight line passing through the center of the first screw hole and the center of the first through-hole with the axis is equal to or less than a degree θ2 of a second inclination angle formed by the intersection of a straight line passing through the center of the second screw hole and the center of the second through-hole with the axis.

2. The insert type cutting instrument according to claim 1, wherein the degree θ1 of the first inclination angle is greater than or equal to 15° and is less than or equal to 45°, andthe degree θ2 of the second inclination angle is greater than or equal to 45° and is less than or equal to 85°.

3. The insert type cutting instrument according to claim 1, wherein an engagement protruded portion protruding from the lower surface of the insert is formed on the lower surface, andan engagement recessed portion which is able to engage with the engagement protruded portion of the insert is formed on an attachment surface of the insert seat.

4. The insert type cutting instrument according to claim 1, wherein an engagement protruded portion protruding from an attachment surface of the insert seat is formed on the attachment surface, andan engagement recessed portion which is able to engage with the engagement protruded portion is formed on the lower surface of the insert.

5. An insert attached to an insert seat of an instrument main body, wherein the insert is formed as a flat polygonal plate, and which has an upper surface formed as a rake surface and a lower surface facing opposite the upper surface, andtwo through-holes which go through from the upper surface to the lower surface are formed in the insert.

6. The insert according to claim 5, wherein an engagement recessed portion which is able to engage with an engagement protruded portion formed on an attachment surface of the insert seat is formed on the lower surface of the insert.

7. The insert according to claim 5, wherein an engagement protruded portion which is able to engage with an engagement recessed portion formed on an attachment surface of the insert seat is formed on the lower surface of the insert.

8. A method for attaching an insert to an instrument main body with the insert type cutting instrument according to claim 1, comprising: pushing the insert toward the base end of the instrument main body and toward the axis of the instrument main body by screwing a first clamping screw member through the first through-hole of the insert into the first screw hole of the instrument main body; andpushing the insert toward the base end of the instrument main body and toward the axis of the instrument main body by screwing a second clamping screw member through the second through-hole of the insert into the second screw hole of the instrument main body.