Machine tool

Patent metadata

Field	Value
Publication number	US-10328543-B2
Application number	US-201715678677-A
Country	US
Kind code	B2
Filing date	Aug 16, 2017
Priority date	Aug 17, 2016
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

A machine tool which removal-machines a workpiece by means of a tool includes a retaining device (a workpiece spindle and a tailstock) that retains the workpiece, a support device (an in-machine robot) that supports the workpiece, in order to suppress deflection of the workpiece retained by the retaining device, and a control device that controls driving of the support device by force control having a force as a control target. Specifically, a supporting force by the support device and a machining force by a tool are measured, and the driving of the support device is controlled so that the supporting force is equal to the machining force.

First claim

The invention claimed is:

1. A machine tool which removal-machines a workpiece, comprising:
a tool;
a retaining device that retains the workpiece;
a support device that supports the workpiece, in order to suppress deflection of the workpiece retained by the retaining device;
a control device that controls driving of the support device by force control having a force as a control target;
a supporting force measurement unit that measures a supporting force of the workpiece by the support device; and
a machining force measurement unit that measures a machining force of the workpiece by the tool, wherein
the control device force-controls the support device based on a comparison result of the measured supporting force and the measured machining force.

2. A machine tool which removal-machines a workpiece, comprising:
a tool;
a retaining device that retains the workpiece;
a support device that supports the workpiece, in order to suppress deflection of the workpiece retained by the retaining device;
a control device that controls driving of the support device by force control having a force as a control target, and
a retaining force measurement unit that measures a retaining force of the workpiece by the retaining device, wherein
the control device force-controls the support device based on a comparison result of an initial retaining force measured before machining by the tool and before supporting by the support device, and a comparison retaining force measured during the machining by the tool and during the supporting by the support device.

3. A machine tool which removal-machines a workpiece, comprising:
a retaining device that retains the workpiece;
a support device that supports the workpiece, in order to suppress deflection of the workpiece retained by the retaining device; and
a control device that controls driving of the support device by force control having a force as a control target, wherein
the control device force-controls the support device based on a comparison result of the measured supporting force or the measured machining force with a theoretical value of the supporting force or the machining force determined based on a machining condition.

4. The machine tool according to claim 1 , wherein
the support device supports the workpiece with an elastic element therebetween.

5. The machine tool according to claim 4 , further comprising:
a rigidity changing mechanism that changes rigidity of the elastic element.

6. A machine tool which removal-machines a workpiece, comprising:
a retaining device that retains the workpiece;
a support device that supports the workpiece, in order to suppress deflection of the workpiece retained by the retaining device; and
a control device that controls driving of the support device by force control having a force as a control target, wherein
the support device comprises:
a multi-degrees-of-freedom robot; and
an end effector attached to the multi-degrees-of-freedom robot, and
the end effector contacts the workpiece and supports the workpiece.

7. The machine tool according to claim 6 , wherein
a plurality of types of the end effectors are prepared, and
an end effector attached to the multi-degrees-of-freedom robot is exchangeable.

8. The machine tool according to claim 2 , wherein
the support device supports the workpiece with an elastic element therebetween.

9. The machine tool according to claim 8 , further comprising:
a rigidity changing mechanism that changes rigidity of the elastic element.

10. The machine tool according to claim 3 , wherein
the support device supports the workpiece with an elastic element therebetween.

11. The machine tool according to claim 10 , further comprising:
a rigidity changing mechanism that changes rigidity of the elastic element.

12. The machine tool according to claim 6 , wherein
the support device supports the workpiece with an elastic element therebetween.

13. The machine tool according to claim 12 , further comprising:
a rigidity changing mechanism that changes rigidity of the elastic element.

Assignees

• Okuma Machinery Works Ltd

Inventors

• Morimura Shoichi

Classifications

• B23B13/126

  Supports · CPC title

• B23Q17/0966

  by measuring a force on parts of the machine other than a motor · CPC title

• B23Q1/766 Primary

  Steadies or rests moving together with the tool support · CPC title

• B23Q17/005 Primary

  by measuring a force, a pressure or a deformation · CPC title

• B23B2260/128

  Sensors · CPC title