Drill

Patent metadata

Field	Value
Publication number	US-9604286-B2
Application number	US-201314759532-A
Country	US
Kind code	B2
Filing date	Jan 29, 2013
Priority date	Jan 29, 2013
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A drill with a cutting fluid supply hole includes: a tool main-body with an axial end cutting-edge, a portion having a discharge flute on a main-body distal end side portion, and a cutting fluid supply hole, the hole having a fan-shaped cross section defined by a front inner-wall surface located along a main-body radial direction on the front side in the drill rotation direction, a rear inner-wall surface located along the radial-direction on the rear side in the drill rotation direction and facing the front inner-wall surface in a main-body circumferential direction, an outer circumferential inner-wall surface made up of a partially cylindrical surface around a drill center line, and an inner circumferential inner-wall surface made up of a partially cylindrical surface around the center line with a curvature radius smaller than that of the outer circumferential inner-wall surface and facing the outer circumferential inner-wall surface in the radial direction.

First claim

The invention claimed is:

1. A drill with a cutting fluid supply hole comprising: a tool main body provided with a cutting edge that is located at an axial end thereof, a flute portion having a discharge flute formed on a distal end side portion of the tool main body for discharging chips generated by the cutting edge, and a cutting fluid supply hole for supplying cutting fluid toward the cutting edge through the inside of the flute portion,
the cutting fluid supply hole having a fan-shaped cross section defined by a front inner wall surface extending along a radial direction of the tool main body on the front side in the rotation direction of the drill, a rear inner wall surface extending along the radial direction on the rear side in the rotation direction of the drill and facing the front inner wall surface in a circumferential direction of the tool main body, an outer circumferential inner wall surface made up of a partially cylindrical surface around a center line of the drill, and an inner circumferential inner wall surface made up of a partially cylindrical surface around the center line of the drill with a curvature radius that is smaller than a curvature radius of the outer circumferential inner wall surface and facing the outer circumferential inner wall surface in the radial direction.

2. The drill with a cutting fluid supply hole of claim 1 , wherein
an angle defined by the front inner wall surface and the rear inner wall surface is 20° to 50° in a cross section orthogonal to a rotation center of the drill, and wherein
where a diameter of the drill is represented by D, the curvature radius of the outer circumferential inner wall surface is 0.25D to 0.35D while the curvature radius of the inner circumferential inner wall surface is 0.15D to 0.20D.

3. The drill with a cutting fluid supply hole of claim 2 , wherein where a reference line is a straight line connecting the center line of the drill and a radially outermost point of one of side-wall surfaces which define the discharge flute and which are opposed to each other in the rotation direction, an angle of 20° to 50° is defined by the reference line and a straight line indicative of a half angle of the angle defined by the front inner wall surface and the rear inner wall surface.

4. The drill with a cutting fluid supply hole of claim 1 , wherein adjacent surfaces are smoothly connected to each other with a curvature radius of 0.015D to 0.045D, the adjacent surfaces being each adjacent two of the front inner wall surface, the rear inner wall surface, the outer circumferential inner wall surface and the inner circumferential inner wall surface, which are adjacent to each other.

Assignees

• Takai Kazuteru
• Osg Corp

Inventors

• Takai Kazuteru

Classifications

• B23B51/02

  Twist drills · CPC title

• B23B2260/082

  Holes · CPC title

• B23B51/06 Primary

  Drills with lubricating or cooling equipment {(B23B51/042 takes precedence)} · CPC title

• B23B2251/408

  Spiral grooves · CPC title

• Y10T408/455

  Conducting channel extending to end of Tool · CPC title