Vibration-damped high-speed tool holder

Patent metadata

Field	Value
Publication number	US-10434581-B2
Application number	US-201515519691-A
Country	US
Kind code	B2
Filing date	Oct 19, 2015
Priority date	Oct 17, 2014
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

A high-speed tool holder includes: a tool shaft for accommodating a tool at its first end, and a machine clamping part which is integrally connected to the tool shaft and forms an interface for clamping in the machine; with the tool shaft being substantially truncated circular cone-shaped, a first diameter at the first end with the tool insertion opening being smaller than a fifth diameter at the second end at the machine clamping part; and a portion of the substantially truncated circular cone-shaped tool shaft having an outwardly bulging, preferably spherical, shape between the tool insertion opening and the machine clamping part.

First claim

The invention claimed is:

1. High-speed tool holder for accommodating a tool at its first end and for clamping it into a machine at its second end, the ends being arranged on the opposite sides of the longitudinal axis of the high-speed tool holder, the high-speed tool holder comprising:
a) a tool shaft which is formed centrally along the longitudinal axis and defines the first end of the high-speed tool holder, a tool insertion opening ( 5 ) with a first bore ( 1 e ) for accommodating the tool being formed at the first end, and
b) a machine clamping part ( 4 ) which is also formed centrally along the longitudinal axis and integrally connected to the tool shaft at an end opposite to the first end, and which forms an interface for clamping into the machine,
c) the tool shaft being substantially truncated circular cone-shaped, with a first diameter (D 1 ) at the first end with the tool insertion opening being smaller than a fifth diameter (D 5 ) at the second end at the machine clamping part, and characterized in that
d) a portion of the substantially truncated circular cone-shaped tool shaft having an outwardly bulging spherical or oval shape between the tool insertion opening and the machine clamping part, resulting in an additional material volume between the substantially truncated circular cone-shaped tool shaft and the outwardly bulging shape.

2. High-speed tool holder according to claim 1 , the tool shaft being divided along the longitudinal axis into a first ( 1 ), a second ( 2 ) and a third portion ( 3 ) serially merging with one another integrally, with
the first portion ( 1 ) being arranged at the first end with the tool insertion opening ( 5 ) and being substantially increasing in truncated circular cone-shape in the direction towards the second portion ( 2 ) from the first diameter (D 1 ) to a second diameter (D 2 );
the second portion ( 2 ) which corresponds to the portion with the outwardly bulging shape having the second diameter (D 2 ) at a location bordering on the first portion ( 1 ) and having a fourth diameter (D 4 ) larger than or equal to the second diameter (D 2 ) at a location bordering on the third portion ( 3 ), with the second portion ( 2 ), over its length, having the outwardly bulging spherical shape with respect to the longitudinal axis; and
the third portion ( 3 ) having the fourth diameter (D 4 ) at a location bordering on the second portion ( 2 ) and further increasing conically up to the fifth diameter (D 5 ).

3. High-speed tool holder according to claim 2 , wherein the lengths of the first portion ( 1 ), the second portion ( 2 ) and the third portion ( 3 ) each make up 20-60% of the overall length of the tool shaft; or
wherein a length of the first and of the second portion taken together amounts to less than 50% of the overall length of the tool shaft; or
wherein the second portion ( 2 ) is entirely arranged in the half of the high-speed tool holder which contains the first end; or
wherein the second portion ( 2 ) is entirely arranged in the third of the high-speed tool holder which contains the first end.

4. High-speed tool holder according to claim 2 , the third portion ( 3 ) having on the inside centrally along the longitudinal axis a third bore ( 3 e ) or a cavity filled with an additional filler.

5. High-speed tool holder according to claim 2 , the first portion ( 1 ) having, at the first end behind the first diameter (D 1 ) along the longitudinal axis, an additional enlargement ( 1 a ) with a seventh diameter (D 7 ), the enlargement ( 1 a ) first increasing from the first diameter (D 1 ), then decreasing behind the seventh diameter (D 7 ) and then conically increasing continuously up to the second diameter (D 2 ) at the transition to the second portion ( 2 ), wherein the additional enlargement ( 1 a ) is adapted to cause locally a higher rigidity and thus a sufficiently strong clamping of the workpiece.

6. High-speed tool holder according to claim 1 , the outwardly bulging shape having a surface with a plurality of dents which are formed similar to the surface of a golf ball or which are groove-shaped transversely to the longitudinal axis or groove-shaped in the direction of the longitudinal axis.

7. High-speed tool holder according to claim 1 , wherein the outwardly bulging shape of the second portion ( 2 ) is formed with a surface which is at least 30% larger than would be the case if the outwardly bulging shape had a smooth surface.

8. High-speed tool holder according to claim 1 , the portion with the outwardly bulging shape having on the inside centrally along the longitudinal axis a second bore ( 2 e ) or a cavity filled with a filler.

9. High-speed tool holder according to claim 8 , wherein the filler of the second and/or of the third bore ( 2 e , 3 e ) comprises one of the following corpuscular fillers or a combination thereof, selected from the group comprising steel balls, chromium steel balls, plastic balls, ceramic balls, quartz sand, quartz, sand, aluminum balls, silibead balls, polyamide balls, polycarbonate balls or other corpuscular components.

10. High-speed tool holder according to claim 9 , wherein the filler of the second and/or of the third bore ( 2 e , 3 e ) comprises, in addition to the at least one corpuscular filler, a viscous liquid or foam which are intended to cause a particularly good vibration damping of the high-speed tool holder.

11. High-speed tool holder according to claim 1 , the high-speed tool holder being formed as a shrink fit chuck wherein the tool shaft clampingly retains the tool by thermal expansion and shrinking or which is adapted to clampingly retain the tool by a screw connector and a clamping sleeve.

12. High-speed tool holder according to o claim 1 , which consists of one of the following materials selected from the group comprising metal, plastic, a composite material, a glass fiber composite material, nylon, 6,6 synthesized, PC, polyamides 12, FDM nylon, ABS, polyetherimides, polycarbonates and/or polysulphones.

13. High-speed tool holder according to claim 1 , the high-speed tool holder being adapted for clamping in a turning, milling or drilling machine.

14. High-speed tool holder according to claim 1 , where the tool is a milling cutter, a drill, a turning tool or a friction tool which is non-coated, coated or anticorrosively coated.

15. High-speed tool holder according to claim 1 ,
wherein the first bore ( 1 e ) is formed sufficiently wide and continuous so that the tool can be inserted therein without a stop; or
wherein the tool shaft is adapted such that it has, coaxial with the first bore ( 1 e ), at least one centric flow channel ( 1 f ) through which a medium can flow; or
wherein the tool shaft is adapted such that it has, at the first end parallel to the first bore ( 1 e ), at least two flow channels ( 1 f ) arranged about the first bore ( 1 e ) symmetrically such that the high-speed tool holder remains balanced, the flow channels ( 1 f ) being formed such that a medium can flow through them; or
wherein the tool shaft is adapted such that it has, at the first end parallel to the first bore ( 1 e ), at least two flow channels ( 1 f ) which are arranged about the first bore ( 1 e ) symmetrically and intersect the first bore ( 1 e ) so that by non-intersected parts of the first bore ( 1 e ), supporting webs for supporting and clamping the tool are formed, the at least two flow channels being open at the first end towards the tool in order to let a medium flow through;
the medium being a gas, air, steam, a liquid, a cooling liquid or a mixture thereof.

Assignees

• Straumann Holding Ag

Inventors

• Kurth Dieter

Classifications

• B23B2260/022

  Balls · CPC title

• B23B2250/16

  Damping of vibrations · CPC title

• B23B31/0261 Primary

  for centering the tool · CPC title

• B23B31/1179 Primary

  using heating and cooling · CPC title

• B23B2231/0244

  Special forms not otherwise provided for · CPC title