NSF Engineering Research Center for Reconfigurable Manufacturing SystemsUniversity of Michigan College of Engineering

In-Line Engine Valve Seat Inspection

Engineering Research Center for

Reconfigurable Manufacturing Systems

2NSF Engineering Research Center for Reconfigurable Manufacturing SystemsUniversity of Michigan College of Engineering

Motivation

Critical dimensional and geometric features

• Seat Angle (with respect to valve guide)• Seat Length• Roundness of critical seat• Run-out of critical seat (with respect to valve guide)

3NSF Engineering Research Center for Reconfigurable Manufacturing SystemsUniversity of Michigan College of Engineering

Currently Used Techniques

Coordinate Measuring Machine Specialized Dial Indicator

4NSF Engineering Research Center for Reconfigurable Manufacturing SystemsUniversity of Michigan College of Engineering

Project Goal

• In-line measurement of valve seat geometry (cycle time ~ 30 seconds)

• Rapid and accurate non-contact measurement

• Measurement of seat angle and seat length from cross section

• Measurement of roundness from multiple cross sections

• Measurement of run-out with respect to valve guide

5NSF Engineering Research Center for Reconfigurable Manufacturing SystemsUniversity of Michigan College of Engineering

Preliminary Setup

Current Setup• 2-axis Aerotech motion stage system• Optimet Conoprobe: single point laser range sensor

Future Setup• Addition of 3rd axis system for multiple cross sections• Portable demonstrator (ME450: senior design class)

6NSF Engineering Research Center for Reconfigurable Manufacturing SystemsUniversity of Michigan College of Engineering

Algorithm for Angle Measurement

Data Acquisition• Data acquired from a single independent valve seat insert• Outliers filtered using Conoprobe’s inbuilt SNR filter

7NSF Engineering Research Center for Reconfigurable Manufacturing SystemsUniversity of Michigan College of Engineering

Algorithm for Angle Measurement

Angle Calculation wrt Horizontal Reference• Linear least squares fit for each angle• Estimate angle with respect to horizontal

8NSF Engineering Research Center for Reconfigurable Manufacturing SystemsUniversity of Michigan College of Engineering

Algorithm for Angle Measurement

Angle Calculation wrt Imaginary Datum• Determine horizontal plane based on intersection points• Horizontal plane used as imaginary datum (instead of valve guide axis)

9NSF Engineering Research Center for Reconfigurable Manufacturing SystemsUniversity of Michigan College of Engineering

Algorithm for Angle Measurement

Angle Calculation wrt Imaginary Datum• Determine horizontal plane based on intersection points• Horizontal plane used as imaginary datum (instead of valve guide axis)

1 2

10NSF Engineering Research Center for Reconfigurable Manufacturing SystemsUniversity of Michigan College of Engineering

Preliminary Results

Angles with respect to horizontal reference

Angle with respect to imaginary datum

29.17 45.16 60.74 44.88

30.38 44.41 59.07 44.69

Angles with respect to horizontal reference

Angle with respect to imaginary datum

29.64 45.11 60.68 44.83

30.63 44.41 58.97 44.68

Run 1

Run 2

11NSF Engineering Research Center for Reconfigurable Manufacturing SystemsUniversity of Michigan College of Engineering

Off-Center Measurements

• Current: Measurement along diameter• Future: Mathematical adjustment for off centered measurement

12NSF Engineering Research Center for Reconfigurable Manufacturing SystemsUniversity of Michigan College of Engineering

Roundness Measurement

• Extract intersection points from multiple cross sections• Estimate roundness from best fit circle

13NSF Engineering Research Center for Reconfigurable Manufacturing SystemsUniversity of Michigan College of Engineering

Next Steps

• Run tests and measurements using newly fixed motion stages

• Repeat repeatability study and accuracy analysis with existing valve seat samples

• ME450 Design project (September to December)• 4 undergraduate design students • Design and build an in-line demonstrator for valve seat measurement

• Investigate and perform feasibility study• Run-out measurement using integrated vision system

NSF Engineering Research Center for Reconfigurable Manufacturing SystemsUniversity of Michigan College of Engineering

Thank You!Questions and Comments ??