US 5,879,113 AGranted

Machine tool

AssigneeKoyo Seiko Co., Ltd.

InventorsHirochika Ueyama, Manabu Taniguchi

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Abstract

A machine tool comprises a spindle unit for raising a spindle on which a cutting tool is mounted by a magnetic force and supporting the spindle. The spindle unit carries out feedback control so as to maintain the spindle in its target position in the radial direction. A feeder for feeding the cutting tool to a work comprises a servo motor for moving the spindle unit relatively to the work. A feeding controller for controlling a feeding operation of the feeder controls the speed of rotation of the servo motor on the basis of feed speed data stored in a memory. The feed speed data comprises a first feed speed corresponding to the time when the cutting tool cuts through an end surface of the work crossing the direction of feeding and a second feed speed corresponding to the time of normal working and higher than the first feed speed.

Claims5

Dependent claims

A machine tool comprising:

a cylindrical main body;
a spindle passed through said main body for transmitting torque to a cutting tool;
an electromagnet for radially supporting said spindle with a clearance therebetween by its magnetic force;
position detecting means for detecting the position in the radial direction of said spindle;
a spindle unit comprising means for controlling the magnetic force of said electromagnet so as to maintain said spindle at its target position based upon a signal from said position detecting means;
feeding means comprising a servo motor for moving said spindle unit relatively to a work and feeding the cutting tool to the work in a predetermined direction of feeding;
feeding controlling means for controlling the speed of rotation of said servo motor based upon feed speed data stored in a memory,
said feed speed data comprising a first feed speed corresponding to a time when the cutting tool cuts through an end surface of the work crossing said direction of feeding and a second feed speed corresponding to a time of normal working and higher than said first feed speed.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/827,608Filed 9 Apr 1997
Granted: 9 Mar 1999
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

G05B 19/4166
Characterised by control of velocity, acceleration or deceleration: controlling feed or in-feed
Y10T 408/65
Cutting by use of rotating axially moving tool: means to drive tool
Y10T 409/304704
With control means energized in response to activator stimulated by condition sensor: in response to cutter or cutter carriage
Y10T 409/30504
With control means energized in response to activator stimulated by condition sensor: to control rate of infeed or return