In-Line Engine Valve Seat Inspection

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In-Line Engine Valve Seat Inspection
Engineering Research Center forReconfigurable
Manufacturing Systems
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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)

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Currently Used Techniques
Coordinate Measuring Machine
Specialized Dial Indicator
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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

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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)

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Algorithm for Angle Measurement

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

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Algorithm for Angle Measurement

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

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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)

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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)

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Preliminary Results
Run 1
Angles with respect to horizontal reference Angles with respect to horizontal reference 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
Run 2
Angles with respect to horizontal reference Angles with respect to horizontal reference 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
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Off-Center Measurements

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

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Roundness Measurement

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

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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

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Thank You!Questions and Comments ??