IN-PROCESS COMPENSATION OF MACHINING OPERATION AND MACHINE ARRANGEMENT

• US 20140256228A1
• Filed: 09/21/2012
• Published: 09/11/2014
• Est. Priority Date: 09/22/2011
• Status: Active Grant

• Current Assignee: ABet SKF
• Original Assignee: ABet SKF
• Inventors: Kaminski, Jacek, Hgns, Stefan, Neguembor, Oscar A.
• Granted Patent: US 9,229,442 B2
• Time in Patent Office: Days
• US Class Current: 451/28
• CPC Class Codes: B23B 2215/12 Bearing races
• CPC Class Codes: B23B 2228/24 Hard, i.e. after being hardened
• CPC Class Codes: G05B 19/404 characterised by control arrangements for compensation, e.g. for backlash, overshoot, tool offset, tool wear, temperature, machine construction errors, load, inertia G05B19/19, G05B19/41 take precedence
• CPC Class Codes: G05B 2219/37374 Deflection
• CPC Class Codes: G05B 2219/49099 Cutting force, torque
• CPC Class Codes: G05B 2219/49168 Compensate feed as function of measured values and manual introduced values
• CPC Class Codes: G05B 2219/49169 Compensation for temperature, bending of tool
• CPC Class Codes: G05B 2219/49184 Compensation for bending of workpiece, flexible workpiece
• CPC Class Codes: G05B 2219/49186 Deflection, bending of tool

Abstract

The present invention relates to a method for performing in-process compensating a machining operation on a workpiece, wherein the compensation process includes generating a control signal representative of magnitude of a contact force exerted on a cutting tool in a normal direction in relation to a machining surface of the workpiece, determining a compensation parameter value based on the control signal, and compensating the machining operation based on the compensation parameter value. The present invention also relates to corresponding machine arrangement for performing a machining operation on a workpiece, such as a hard turning process.

Claims

1. A method for compensating a machining operation on a workpiece, the method comprising:

performing a machining operation which physically removes material from the workpiece by subjecting a machining surface of the workpiece with a cutting tool, and by providing a relative rotational movement and a relative movement between the workpiece and the cutting tool, wherein

the method further comprises in-process compensation of the machining operation, the in-process compensation comprising;

generating a control signal representative of magnitude of a contact force exerted on the cutting tool in a normal direction in relation to the machining surface,

determining a compensation parameter value based on the control signal, and

compensating the machining operation based on the compensation parameter value.

2. The method according to claim 1, wherein the step of compensating the machining operation further

compensating the cutting tool in relation to the workpiece.

3. The method according to claim 2, wherein the step of compensating the cutting tool further comprises actuating the cutting tool in relation to the workpiece in the normal direction.

4. The method according to claim 1, wherein the step of compensating the machining operation further comprises adjusting a feed rate of the cutting tool in relation to the workpiece.

5. The method according to claim 1, wherein the step of determining a compensation parameter value further comprises determining a deflection parameter value based on the control signal, wherein

the deflection parameter value is representative of in-process deflection of the cutting tool in relation to the workpiece, and wherein

the compensation parameter value is determined based on the deflection parameter value.

6. The method according to claim 1, wherein the in-process compensation steps are controlled independently from the step of performing the machining operation.

7. The method according to claim 1, wherein the workpiece is a cylindrically shaped member for use as a rolling bearing component, such as a ring or a rolling body, and

wherein the normal direction coincides with the radial direction of the cylindrically shaped member.

8. The method according to claim 1, wherein in the step of compensating the machining operation compensates for profile errors and/or un-roundness of the workpiece.

9. The method according to claim 1, wherein the method is a turning process, or hard turning process.

10. A computer readable medium embodying a computer program product for compensating a machining operation on a workpiece, the computer program product comprising code configured to, when executed by a processor:

perform a machining operation which physically removes material from the workpiece by subjecting a machining surface of the workpiece with a cutting tool, and by providing a relative rotational movement and a relative movement between the workpiece and the cutting tool, and

perform in-process compensation of the machining operation, wherein the compensation comprises;

generate a control signal representative of magnitude of a contact force exerted on the cutting tool in a normal direction in relation to the machining surface,

determine a compensation parameter value based on the control signal, and

compensate for the machining operation based on the compensation parameter value.

11. A machine arrangement for a machining operation of a workpiece, the machining operation providing physical removal of material from the workpiece, the machine arrangement comprising:

a workpiece holder arranged to secure and rotate the workpiece,

a cutting tool attached to a tool holder, and

a motion device for the tool holder,

wherein the motion device is arranged to place the cutting tool in contact with a machining surface of the workpiece, and to move the cutting tool in relation to the workpiece according to machining operation parameters, wherein the arrangement further comprises;

a sensor arranged to generate a control signal representative of magnitude of a contact force exerted on the cutting tool in a normal direction in relation to the machining surface, and

a compensation control unit operatively connected to the sensor and arranged to determining a compensation parameter based on the control signal,

wherein compensation control unit is arranged to provide in-process compensation of the machining operation based on the compensation parameter.

12. The machine arrangement according to claim 11, wherein the compensation control unit is arranged to adjust the machining operation parameters in real-time based on the control signal, and

wherein the motion device is arranged to adjust the cutting tool in relation to the workpiece based on the adjusted machining operation parameters.

13. A machine arrangement for machining operation of a workpiece, the machining operation providing physical removal of material from the workpiece, the machine arrangement comprising:

a workpiece holder arranged to secure and rotate the workpiece during machining operation,

a cutting tool attached to a tool holder, and

a motion device supporting the tool holder,

wherein the motion device is arranged to provide the cutting tool in contact with a machining surface of the workpiece, and to move the cutting tool in relation to the workpiece according to machining operation parameters, wherein the arrangement further comprises;

an actuator (28) supporting the tool holder, the actuator is arranged between the motion device and the tool holder,

wherein the actuator is arranged to adjust the position of the tool holder in relation to the motion device.

14. The machine arrangement according to claim 13, wherein the actuator is arranged to actuate the cutting tool in relation to the workpiece in the normal direction.

15. The machine arrangement according to claim 13, wherein the actuator has a working range less than 500 microns.

16. The machine arrangement according to claim 13, further comprising a sensor arranged to generate a control signal representative of magnitude of a contact force exerted on the cutting tool in a normal direction in relation to the machining surface, and

a compensation control unit operatively connected to the sensor and arranged to determining a compensation parameter based on the control signal,

wherein the actuator is arranged to, at least partly, adjust the position of the cutting tool based on the control signal.