# US 8,784,156 B2 · Grinding method for grinding a workpiece using a grinding wheel

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- Number: US 8,784,156 B2
- Document ID: US8784156B2
- Status: Granted
- Kind: B2
- Application number: 13/178,871
- Filed: 2011-07-08
- Published: 2012-02-02
- Granted: 2014-07-22
- Earliest claimed: 2010-07-27
- Assignees: Jtekt Corporation
- Applicants: Makoto Tano; Yoshio Wakazono
- Inventors: Makoto Tano; Yoshio Wakazono
- Web page: https://patentgrep.com/patent/US8784156B2

## CPC

- G05B 19/4163: {Adaptive control of feed or cutting velocity (without NC B23Q15/12)}
- B24B 1/00: Processes of grinding or polishing; Use of auxiliary equipment in connection with such processes
- B24B 5/02: involving centres or chucks for holding work
- B24B 49/003: {involving acoustic means}
- B24B 49/045: {Specially adapted gauging instruments}
- B24B 49/18: taking regard of the presence of dressing tools
- B24B 53/053: using a rotary dressing tool
- G05B 2219/37269: Ultrasonic, ultrasound, sonar
- G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G)
- B24B: MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING (grinding of gear teeth B23F, of screw-threads B23G1/36; by electro-erosion B23H; abrasive or related blasting B24C; tools for grinding, buffing or sharpening B24D; polishing compositions C09G1/00; abrasives C09K3/14; electrolytic etching or polishing C25F3/00; grinding arrangements for use on assembled railway tracks E01B31/17); DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS

## Abstract

A core grinding wheel that has a grinding layer on an outer periphery of a core is used. An ultrasonic wave is output from an ultrasonic sensor to the grinding layer via grinding fluid. An ultrasonic measuring device control unit calculates a thickness of the grinding layer on the basis of a sonic velocity in the grinding layer and an arrival time difference between a reflected wave from a surface of the grinding layer and a reflected wave from a surface of the outer periphery of the core. A grinding process and a truing process are controlled on the basis of an outside diameter of the grinding wheel, which is calculated on the basis of the measured thickness of the grinding layer and an outside diameter of the core.

## Claims

### Claim 1

A grinding method for grinding a workpiece using a grinding wheel that has a grinding layer on an outer periphery of a core of the grinding wheel, comprising:
recording an outside diameter of the core, a first thickness that is a thickness of the grinding layer and a first time difference that is a time difference in arrival at an ultrasonic sensor between a reflected wave from a surface of the grinding layer having the first thickness and a reflected wave from a surface of the outer periphery of the core;
recording a second time difference that is a time difference in arrival at the ultrasonic sensor between a reflected wave from a surface of the grinding layer having a second thickness that is a thickness of the grinding layer and a reflected wave from the surface of the outer periphery of the core;
calculating a decrease in time difference, which is a difference between the first time difference and the second time difference;
calculating a predetermined reduction amount by a product of a component sonic velocity, which is a sonic velocity in a component that constitutes the grinding layer, and the decrease in time difference;
calculating the second thickness by subtracting the predetermined reduction amount from the first thickness;
calculating an outside diameter of the grinding wheel based on a sum of double the second thickness and the outside diameter of the core; and
controlling a grinding operation of the workpiece and a truing operation of the grinding wheel on the basis of the calculated outside diameter of the grinding wheel.

### Claim 2 (depends on 1)

The grinding method according to claim 1, further comprising measuring a decrease in time difference between the first time difference and the second time difference at a plurality of points, wherein the predetermined reduction amount is calculated on condition that the component sonic velocity is the fastest among sonic velocities in components that constitute the grinding layer and the decrease in time difference is the smallest among the decreases in time differences measured at the plurality of points.

### Claim 3 (depends on 1)

The grinding method according to claim 1, further comprising measuring a decrease in time difference between the first time difference and the second time difference at a plurality of points, wherein the predetermined reduction amount is calculated on condition that the component sonic velocity is the slowest among sonic velocities in components that constitute the grinding layer and the decrease in time difference is the largest among the decreases in time differences measured at the plurality of points.

### Claim 4 (depends on 1)

The grinding method according to claim 1, wherein the outside diameter of the grinding wheel is measured while the workpiece is being ground, and the grinding operation is controlled using an amount of change in the outside diameter of the grinding wheel as an amount of wear of the grinding wheel due to grinding.

### Claim 5 (depends on 1)

The grinding method according to claim 1, wherein the outside diameter of the grinding wheel is measured while the grinding wheel is being trued, and the truing operation is controlled using an amount of change in the outside diameter of the grinding wheel as a removal amount of the grinding wheel due to truing.