Milling tool and a tool body

Patent metadata

Field	Value
Publication number	US-10099304-B2
Application number	US-201514703947-A
Country	US
Kind code	B2
Filing date	May 5, 2015
Priority date	May 6, 2014
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

A milling tool includes a tool body having a peripheral surface and a central rotation axis. A number of cutting teeth protrude from the peripheral surface, a front end set of the cutting teeth arranged along a front end portion of an imaginary helix concentric with the central rotation axis, and a back end set along a back end portion of the helix. The cutting teeth engage the workpiece successively, starting with the foremost cutting tooth of the front end set. The back end set includes at least three along the helix adjacent cutting teeth arranged at a constant first radial distance from the central rotation axis. The front end set has at least two adjacent cutting teeth arranged at an along the helix non-constant second radial distance from the central rotation axis. The second radial distance is smaller than the first radial distance and increases successively along the helix.

First claim

The invention claimed is:

1. A milling tool for hobbing of a workpiece having cylindrical cogs, comprising:
a tool body having a peripheral surface and two opposite ends between which a central rotation axis extends, the tool body being rotatable in a predetermined direction of rotation around the central rotation axis; and
a number of spaced-apart cutting teeth protruding from the peripheral surface, each cutting tooth having a cutting edge and a chip surface, a front end set of said cutting teeth being arranged along a front end portion of an imaginary helix concentric with the central rotation axis, and a back end set of said cutting teeth being arranged along an adjacent back end portion of said helix, the cutting teeth being arranged to engage the workpiece successively along the helix, starting with a foremost cutting tooth of the front end set, wherein the back end set of cutting teeth includes at least three along the helix adjacent cutting teeth being arranged at an along the helix constant first radial distance from the central rotation axis, wherein the front end set of cutting teeth includes at least two along the helix adjacent cutting teeth arranged at an along the helix non-constant second radial distance from the central rotation axis, the second radial distance being smaller than the first radial distance and increasing successively along the helix from the foremost cutting tooth, wherein the second radial distance increases with a distance Δd of 0.02 h≤Δd≤0.1h mm per cutting tooth along the helix, wherein h is the tooth height of a cutting tooth of the back end set, the cutting teeth being configured as replaceable inserts and wherein all said cutting inserts are identical, the front end portion extending along less than one complete turn of the helix.

2. The milling tool according to claim 1 , wherein the second radial distance increases with a distance Δd per cutting tooth along the helix, wherein Δd is a function of an angular distance from the foremost cutting tooth.

3. The milling tool according to claim 2 , wherein the distance Δd is constant or substantially constant for each pair of along the helix adjacent cutting teeth.

4. The milling tool according to claim 2 , wherein the distance Δd is non-constant along the helix.

5. The milling tool according to claim 2 , wherein an angular separation between each pair of along the helix adjacent cutting teeth is constant or substantially constant.

6. The milling tool according to claim 1 , wherein the helix has a constant or substantially constant axial pitch.

7. The milling tool according to claim 1 , wherein all cutting teeth of the back end set are arranged at said constant first radial distance from the central rotation axis.

8. The milling tool according to claim 1 , wherein the cutting teeth are arranged along less than two complete turns of the helix.

9. A tool body for a milling tool formed for hobbing of a workpiece having cylindrical cogs, the tool body comprising:
a peripheral surface and two opposite ends between which a central rotation axis extends, the tool body being rotatable in a predetermined direction of rotation around the central rotation axis;
a number of spaced-apart insert seats arranged in the peripheral surface, a front end set of said insert seats being arranged along a front end portion of an imaginary helix concentric with the central rotation axis, and a back end set of said insert seats being arranged along an adjacent back end portion of said helix, each insert seat being arranged to receive a replaceable cutting insert such that identical cutting inserts, when mounted, are arranged to engage the workpiece successively along the helix, starting with the cutting insert mounted in a foremost insert seat of the front end set, wherein each insert seat includes stopping means for fixing the respective cutting insert in a radial direction, wherein the back end set of insert seats includes at least three along the helix adjacent insert seats with respective stopping means arranged at an along the helix constant first radial distance from the central rotation axis, and wherein the front end set of insert seats includes at least two along the helix adjacent insert seats with respective stopping means arranged at an along the helix non-constant second radial distance from the central rotation axis, the second radial distance being smaller than the first radial distance and increasing successively along the helix from the foremost insert seat, wherein the second radial distance increases with a distance Δd of 0.02 h≤Δd≤0.1h mm per cutting tooth along the helix, wherein h is the tooth height of a cutting tooth of the back end set, the front end portion extending along less than one complete turn of the helix.

10. The tool body according to claim 9 , wherein the front end portion of the helix is formed as a part of a truncated conical helix.

11. The tool body according to claim 9 , further comprising at least two detachably interconnected disc-shaped segments, each segment including a hub part having two opposite plane-parallel end surfaces extending perpendicularly to the central rotation axis, a peripheral cam configured to receive at least two spaced-apart cutting inserts, and interconnection means for interconnecting the segment with a neighbouring segment.

Assignees

• Sandvik Intellectual Property
• Sandvik Intellectual Property Inc

Inventors

• Sjoo Sture

Classifications

• Y10T407/1725

  including holder having seat for inserted tool · CPC title

• B23F21/166 Primary

  in exchangeable arrangement · CPC title

• Y10T407/1715

  Hob · CPC title