Machining tool and workpiece measurement method

Patent metadata

Field	Value
Publication number	US-2021237163-A1
Application number	US-201816887355-A
Country	US
Kind code	A1
Filing date	Dec 21, 2018
Priority date	Jan 25, 2018
Publication date	Aug 5, 2021
Grant date	—

Abstract

A machine tool improving measurement accuracy of a machined workpiece diameter. A machine tool comprises a displacement sensor mounted on at least one of a guide bush and a spindle supporting unit. The machine tool further comprises a calculating unit which calculates a diameter of the machined workpiece based on a measurement value of the machined workpiece by the displacement sensor. The spindle is movable back and forth in an axial direction. The spindle is retracted after machining to bring a machined portion of the workpiece to a predetermined measurement position in the axial direction to allow the displacement sensor to measure the machined portion.

First claim

1 . A machine tool comprising:
a displacement sensor mounted on at least one of a guide bush and a spindle supporting unit, the guide bush supporting a workpiece on a front side of a spindle holding the workpiece; and a calculating unit which calculates a diameter of the machined workpiece based on a measurement value of the machined workpiece by the displacement sensor.

2 . The machine tool of claim 1 , wherein the spindle is movable back and forth in an axial direction, and
wherein the spindle is retracted after machining to bring a machined portion of the workpiece to a predetermined measurement position in the axial direction to allow the displacement sensor to measure the machined portion.

3 . The machine tool of claim 1 , wherein the guide bush comprises a cylindrical non-rotatable section and a rotatable section rotatable in synchronization with the spindle,
the rotatable section is inside the non-rotatable section so as to support the workpiece, the rotatable section has a through-hole to expose part of the workpiece, and the displacement sensor mounted on the non-rotatable section measures the workpiece through the through-hole of the rotatable section.

4 . The machine tool of claim 2 , wherein the guide bush comprises a cylindrical non-rotatable section and a rotatable section rotatable in synchronization with the spindle,
the rotatable section is inside the non-rotatable section so as to support the workpiece, the rotatable section has a through-hole to expose part of the workpiece, and the displacement sensor mounted on the non-rotatable section measures the workpiece through the through-hole of the rotatable section.

5 . The machine tool of claim 1 , wherein the spindle supporting unit is provided with the guide bush in a detachable manner, and
the displacement sensor mounted on the spindle supporting unit measures the workpiece held by the spindle in a state that the guide bush is detached from the supporting unit.

6 . The machine tool of claim 2 , wherein the spindle supporting unit is provided with the guide bush in a detachable manner, and
the displacement sensor mounted on the spindle supporting unit measures the workpiece held by the spindle in a state that the guide bush is detached from the supporting unit.

7 . The machine tool of claim 1 further comprising a temperature sensor which measures a temperature around a position where the displacement sensor is mounted, wherein the calculating unit corrects the measurement value of the workpiece by the displacement sensor according to a measurement value by the temperature sensor and calculates the diameter of the workpiece based on the corrected measurement value.

8 . The machine tool of claim 2 further comprising a temperature sensor which measures a temperature around a position where the displacement sensor is mounted, wherein the calculating unit corrects the measurement value of the workpiece by the displacement sensor according to a measurement value by the temperature sensor and calculates the diameter of the workpiece based on the corrected measurement value.

9 . The machine tool of claim 3 further comprising a temperature sensor which measures a temperature around a position where the displacement sensor is mounted, wherein the calculating unit corrects the measurement value of the workpiece by the displacement sensor according to a measurement value by the temperature sensor and calculates the diameter of the workpiece based on the corrected measurement value.

10 . The machine tool of claim 4 further comprising a temperature sensor which measures a temperature around a position where the displacement sensor is mounted, wherein the calculating unit corrects the measurement value of the workpiece by the displacement sensor according to a measurement value by the temperature sensor and calculates the diameter of the workpiece based on the corrected measurement value.

11 . The machine tool of claim 5 further comprising a temperature sensor which measures a temperature around a position where the displacement sensor is mounted, wherein the calculating unit corrects the measurement value of the workpiece by the displacement sensor according to a measurement value by the temperature sensor and calculates the diameter of the workpiece based on the corrected measurement value.

12 . The machine tool of claim 6 further comprising a temperature sensor which measures a temperature around a position where the displacement sensor is mounted, wherein the calculating unit corrects the measurement value of the workpiece by the displacement sensor according to a measurement value by the temperature sensor and calculates the diameter of the workpiece based on the corrected measurement value.

13 . A workpiece measurement method comprising:
measuring a machined workpiece by a displacement sensor mounted on at least one of a guide bush and a spindle supporting unit, the guide bush supporting the workpiece on a front side of a spindle holding the workpiece; and calculating a diameter of the machined workpiece based on a measurement value of the machined workpiece by the displacement sensor.

Assignees

• Star Mfg Co

Inventors

• Kaku Norio

Classifications

• B23B25/06 Primary

  Measuring, gauging, or adjusting equipment on turning-machines for setting-on, feeding, controlling, or monitoring the cutting tools or work (measuring devices or gauges G01B) · CPC title

• B23B7/06

  with sliding headstock · CPC title

• B23Q17/20

  for indicating or measuring workpiece characteristics, e.g. contour, dimension, hardness · CPC title

• B23Q17/2466 Primary

  Diameter · CPC title

• B23B13/125

  Feed collets (feeding device having intermittent movement being placed in the spindle including two collets B23B13/024; collet chucks B23B31/20) · CPC title