Download Roundness Instrumentation

机械制造技术基础专题讲座
圆度测量技术
高国富
圆度测量
1
简介
4
偏心和跳动
7
测量误差及影响
2
测量方法
5
数据处理
8
间断表面测量
3
参考圆
6
坡度和真圆偏离量
9
误差分离
Roundness Introduction
Roundness Introduction
Why Measure Roundness?
• Functionality
Con Rod
Cream Dispenser
Conveyor Roller
Roundness Introduction
Why Measure Roundness?
• Efficiency
Ball Joint
Hip Joint
Bearing Race
Roundness Introduction
Why Measure Roundness?
• Economy
Engine Performance
Injector Components
Turbine wheel
Roundness Introduction
The Effects of Out of Roundness
Bearing
A A A
A
B B B
A
B
Rotating Shaft
Lubricant
Shaft in a Plain Bearing
Roundness Introduction
The Effects of Out of Roundness
Bearing
Rotating Shaft
Lubricant
Ovality of a Bore
Measurement Methods &
Instrumentation
Measurement Methods & Instrumentation
Workbench Methods
Measuring Roundness using the
Three Point Method
Dial Test Indicator
Rotating Part
Vee Block
= 3 points of Contact
Measurement Methods & Instrumentation
Workbench Methods
Measuring Roundness using the
Three Point Method
Maximum Measured
Movement
Simple but Has
Limitations
Vertical Movement of Part
Measurement Methods & Instrumentation
Workbench Methods
Measuring Roundness using
Calliper Gauging Techniques
Measured
Diameter
Measured
Diameter
Caliper
Measurement Methods & Instrumentation
Workbench Methods
Measuring Roundness using
Calliper Gauging Techniques - Tri Lobed Part
Measurement Methods & Instrumentation
Workbench Methods
Measuring Roundness using
Calliper Gauging Techniques - Tri Lobed Part
As Part Rotates Calliper
Distance Remains
Constant
Measurement Methods & Instrumentation
Workbench Methods
Measuring Roundness using Point Probe Method (CMM)
Plug Gauge
Centre Established by Point Probe
Centre Established by Point Probe
Measurement Methods & Instrumentation
Workbench Methods
Measuring Roundness using a Lathe and DTI
Dial Movement Includes;
1. Concentricity of
Component Axis to Lathe
Spindle Axis
2.Errors in Lathe Spindle
3.Errors in Component
Measurement Methods & Instrumentation
Roundness Instrumentation
Spindle (Rotating Datum Axis)
Spindle
Measurement Methods & Instrumentation
Roundness Instrumentation
Spindle - Centring and Levelling Table
Y
B
X
A
Manual Centring and Levelling Table
Automatic Centring and Levelling Table
Measurement Methods & Instrumentation
Roundness Instrumentation
C and L Table Alignment of Component & Spindle Axes
Component Axis
Spindle Axis
Spindle
Measurement Methods & Instrumentation
Roundness Instrumentation
Instrument Gauge
Gauge
Measurement Methods & Instrumentation
Roundness Instrumentation
Force Control
Adjustable Stylus Retainer
Instrument Gauge
Measurement Methods & Instrumentation
Roundness Instrumentation
Instrument Stylus
Stylus
Measurement Methods & Instrumentation
Roundness Instrumentation
Instrument Stylus
X
Effective Length
Stylus Tip
Pivot
Point
Measurement Methods & Instrumentation
Roundness Instrumentation
Instrument Stylus
100mm
± 1mm Range
200mm
± 2mm Range
Measurement Methods & Instrumentation
Roundness Instrumentation
Ruby and Sapphire Styli
1st Measurement
Repeat Measurement
Effects of Ruby and Sapphire Styli Tips on Aluminium Components
Measurement Methods & Instrumentation
Roundness Instrumentation
Effects of Tool Marks on a Roundness Measurement
Measurement Using a Ball Tip Stylus
Measurement Methods & Instrumentation
Roundness Instrumentation
Effects of Tool Marks on a Roundness Measurement
Measurement Using a Hatchet Stylus
Measurement Methods & Instrumentation
Roundness Instrumentation
Hatchet Styli Tip Dimensions
Effective Stylus Tip Radius
Hatchet Radius
Measurement Methods & Instrumentation
Roundness Instrumentation
Stylus Tip - Mechanical Filtering
90°
180°
0°
270°
Displayed Result
Component Profile
Measurement Methods & Instrumentation
Roundness Instrumentation
Data Processing
Measurement Methods & Instrumentation
Roundness Instrumentation
Data Points
Measured Data Points
Measurement Methods & Instrumentation
Roundness Instrumentation
Data Points
90°
1 Data Point =
Data Point
Gauge Reading (µm)
+
Radial Arm Position
(mm)
180°
Component Centre
+
Angular Position (Deg)
270°
0°
Measurement Methods & Instrumentation
Roundness Instrumentation
Data Points
90°
Spindle Axis
Component Axis
Eccentricity with
respect to Spindle
(Datum) Axis
180°
Component Centre
Component Centre
270°
0°
Measurement Methods & Instrumentation
Roundness Instrument Types
Rotating Table
SPINDLE AND
COLUMN
Measurement Methods & Instrumentation
Roundness Instrument Types
Rotating Table
Designed to Measure Small to Medium Size
Components
Measurement Methods & Instrumentation
Roundness Instrument Types
Rotating Spindle
Measurement Methods & Instrumentation
Roundness Instrument Types
Rotating Spindle
Designed to Measure Large Componets
with an Offset Load
Reference Circles
Reference Circles
Four Types of Reference Circle
• Least Squares Circle (LS)
• Minimum Zone (MZ)
• Maximum Inscribed (MI)
• Minimum Circumscribed (MC)
Reference Circles
Four Types of Reference Circle
• Least Squares Circle (LS)
Least Squares Circle
Maximum Valley (RONv)
Out of Roundness (RONt) = RONv + RONp
Note: RONt =
Maximum Peak (RONp)
Reference Circles
Four Types of Reference Circle
• Minimum Zone (MZ)
Circle Used for Radius Measurement
R
Out of Roundness (RONt) = R
Note: RONt =
Minimum Zone Circles
Reference Circles
Four Types of Reference Circle
• Maximum Inscribed (MI)
Maximum Inscribed Circle
Out of Roundness (RONt) = R
Note: RONt =
R
Reference Circles
Four Types of Reference Circle
• Minimum Circumscribed (MC)
Out of Roundness (RONt) = R
R
Note: RONt =
Minimum Circumscribed Circle
Reference Circles
Reference Circle Differences
• Least Squares (LS)
Maximum Valley (RONv)
Maximum Peak (RONp)
RONp + RONv = RONt
Reference Circles
Reference Circle Differences
• Minimum Zone (MZ)
RONt
Reference Circles
Reference Circle Differences
• Maximum Inscribed (MI)
RONt
Reference Circles
Reference Circle Differences
• Minimum Circumscribed (MC)
RONt
Reference Circles
Reference Circle Differences
LS Circle
MZ Circle
MI Circle
MC Circle
Reference Circles
Reference Circle Differences
Error From the MC Circle
MC Circle
Error From the MI Circle
MI Circle
Reference Circles
Reference Circle Differences
MI Circle
Error From the MI Circle
MC Circle
Error From the MC Circle
Eccentricity, Concentricity &
Run-Out
Eccentricity, Concentricity & Run-Out
Eccentricity轮廓中心偏离基准轴线
90 °
Profile Centre
Ecc
Ecc (E) = Eccentricity Magnitude (µm)
Ecc Pos (
) = Eccentricity Angle (Deg)
180 °
0°
Datum Point
Note; in this example Ecc = 130 °
270 °
Eccentricity, Concentricity & Run-Out
Eccentricity - Establishing the
Correct Position 90 °
180 °
Instrument Table Top
270 °
0°
Eccentricity, Concentricity & Run-Out
Eccentricity - Establishing the
Correct Position
Scale 50µm/div .
Wrong Position
90°
180°
0°
Ecc (E) = 10 µm
Ecc Pos (
) = 130 Deg
270°
Eccentricity, Concentricity & Run-Out
Eccentricity - Establishing the
Correct
Position
Correct
Position
Ecc (E) = 10 µm
Ecc Pos (
) = 130 Deg
Eccentricity, Concentricity & Run-Out
Concentricity轮廓圆心绕基准点旋转所形成圆的直径
Scale 50µm/div .
Concentricity
90°
= Conc
180°
0°
Datum Position
Profile Centre
270°
Concentricity = 2x Eccentricity
Eccentricity, Concentricity & Run-Out
Run-Out
Measuring Run-Out (TIR) using a Lathe and DTI
Dial Movement Includes;
1. Concentricity of
Component Axis to Lathe
Spindle Axis
2.Errors in Lathe Spindle
3.Errors in Component
Eccentricity, Concentricity & Run-Out
Run-Out
R = Runout (
)
Nearest Point on Profile
to Datum Axis
R
Datum Axis
Farthest Point on
Profile to Datum Axis
Eccentricity, Concentricity & Run-Out
Run-Out
Run- Out < Concentricity
Datum Centre
Direction of Peak
Direction of Eccentricity
Component Centre
Data Points
Data Points
Each Data Point Has an Angular Position
Data Points
Minimum Required Number of Data Points
Data Points
LS Circle
Data Points
Minimum Required Number of Data Points
Sampling Interval is too Large to Define the True Signal
Data Points
Measurement Using Reduced Data Points
Critical Features are
Missed
Data Points
The Effect of Component Diameter
Component A
Component B
Slope & Departure From True
Circle (DFTC)
Slope & Departure From True Circle (DFTC)
Slope
Peak to Valley Roundness is Within Specification But...
Bearing Assembly
All of the Error is in One Position
Slope & Departure From True Circle (DFTC)
Slope Will Cause a Change in Velocity
Deceleration
Acceleration
Slope & Departure From True Circle (DFTC)
Change in Velocity Will Cause Excessive Wear
Bearing Assembly
Slope & Departure From True Circle (DFTC)
Slope - Definition
半径随角度的变化率
θ R
r
Slope = (R- r)/θ
Slope & Departure From True Circle (DFTC)
Slope - Calculation Method
Slope for Each Data Point is Calculated
Slope & Departure From True Circle (DFTC)
Slope - Results Display
Slope & Departure From True Circle (DFTC)
DFTC：工件轮廓一定角度位置对真圆的偏离量
Leakage
Slope & Departure From True Circle (DFTC)
DFTC - Definition
DFTC
DFTC Window
Slope & Departure From True Circle (DFTC)
DFTC - Results Display
Measurement Errors &
Effects
Measurement Errors & Effects
Asperity Effects on MC, MZ & MI Reference Circles
MC Circle
Centre
Original Datum
Shifted Datum
Asperity
Measurement Errors & Effects
Asperity Effects on LS Reference Circle
Asperity Has little Effect on the LS Circle
Centre
LS Circle
Centre
Asperity
LS Circle
Centre
Measurement Errors & Effects
Different Reference Circle, Different Centre
LS Reference Circle
LS Centre
MC Centre
MCReference Circle
Measurement Errors & Effects
Cosine Errors
Stylus Centre and Component Centre
Coincident
90°
180°
0°
270°
Measurement Direction
Measurement Errors & Effects
Cosine Errors
Stylus Centre Out of Line with Component
Centre
90°
Point of Contact
θ
180°
270°
0°
Measurement Direction
Measurement Errors & Effects
Cosine Errors
90°
Smaller Diameter Component, Larger Angular
Error
Point of Contact
45°
180°
0°
Measurement Direction
Measurement Errors & Effects
Cosine Errors
Deflection = Cosine 45° x Deviation
90°
45°
2µm Deflection
45°
0°
Measurement Errors & Effects
Cresting Error Caused By Poor Centring & Leveling
Internal Measurement on a Tilted Cylinder
Measurement Direction
Change in angular position of each plane with
respect to component axis
Measurement Errors & Effects
Cresting Error Caused By Poor Centring & Leveling
True Component Centres
Measurement Direction
Calculated Centre
Measurement Errors & Effects
Cresting Error Caused By Poor Centring & Leveling
True Component Axis
Calculated Axis
Measurement Errors & Effects
Effects of Stylus Force
Filtered Profile
Excessive Stylus Force Can Cause High Frequency Errors
Measurement Errors & Effects
Effects of Stylus Force
Unfiltered Profile
Excessive Stylus Force Can Cause High Frequency Errors
Measurement Errors & Effects
Effects of Stylus Force
Filtered Profile
Profile Changes Shape After Repeat Measurement
Measurement Errors & Effects
Effects of Stylus Force
Unfiltered Profile
After Repeat Measurement - High Frequencies Have Shifted
Measurement Errors & Effects
Effects of Stylus Force
Filtered Profile
After Filtering -Shape Changes
Measurement Errors & Effects
Effects of Stylus Force
Unfiltered Profiles
B
A
Filtered Profiles
A
B
Interrupted Surfaces & Data
Removal
Interrupted Surfaces & Data Removal
Associated Problems
Roundness Measurement on an Helical Surface
Interrupted Surfaces & Data Removal
Associated Problems
Roundness of OD Required...
圆度误差超差
测头损坏
Result is Unrepresentative of OD Roundness
Interrupted Surfaces & Data Removal
Stylus Bounce
Peak Due to Stylus Bounce
Stylus Bounce During Measurement
Displayed Result
Interrupted Surfaces & Data Removal
Stylus Stop Attachment
Valley Depth Limited by Stop Attachment
Interrupted Surfaces & Data Removal
Gauge Underrange
Gauge Underrange Set to -50µm
Gauge Range is Now +1.0mm to -50µm
Interrupted Surfaces & Data Removal
Automatic Data Removal
Base Line
Edge level
Total Data Removed
Gauge Underrange Level
Hole Deletion Angle
Interrupted Surfaces & Data Removal
Automatic Data Removal
Excluded Data
Roundness Profile After Data Removal
Interrupted Surfaces & Data Removal
Automatic Asperity Removal
Roundness Result - Including
Asperities
RONt 14.73µm
Ecc 13.28µm
Ecc Pos 30.3°
Interrupted Surfaces & Data Removal
Automatic Asperity Removal
Roundness Result - Excluding
Asperities
RONt 1.76µm
Ecc 13.23µm
Ecc Pos 31.0°
Interrupted Surfaces & Data Removal
Automatic Asperity Removal
Asperity’s Centre is Based on the Position of its Peak
Asperity Peak Height
Half Asperity Peak Height,
and Width of Asperity at this Height
Base line
Asperity Width
Asperity Removal Length
Error Separation
Error Separation
Combined Errors
Component Error
Spindle Error
Error Separation
Combined Errors
Component Error +
Spindle Error
Combined Error
Error Separation
Component Measured at a Different Angle
Component Rotated
Component Error
Spindle Error
Error Separation
Phase Shift Produces a Different Result
Component Rotated
Component Error +
Spindle Error
New Combined
Error
Error Separation
Phase Shift is Usually Ignored
Combined Error 1
Combined Error 2
Error Separation
90°
45°
135°
180°
Hemisphere
0°
Hemisphere
Rotary Table
Rotary Table
Error Separation
LSC Deviations at 45° Increments
+3
+2
-3
45°
0° +2
+3
+0
-2
-2
-1
45°
-2
0° +1
+4
+1
-3
-1
-2
Component Error
Spindle Error
Error Separation
Combined Error Table
Spindle Position (Degrees)
Component / Rotary Table Position (Degrees)
0
45
90
135
180
225
270
315
Total error
0
3
-3
5
-5
7
-5
-3
1
0
45
0
0
0
1
2
-4
-2
3
0
90
3
-5
6
-4
3
-3
0
0
0
135
-2
1
1
-3
4
-1
-3
3
0
180
4
-4
2
-2
6
-4
0
-2
0
225
-1
-3
3
0
3
-1
-5
4
0
270
0
-2
5
-3
6
-6
1
-1
0
315
1
0
2
0
1
0
-4
0
0
Spindle
Error
1
-2
3
-2
4
-3
-2
1
0
Error Separation
Calculating the True Component Error
Degrees
Combined Error
0
45
90
135
180
225
270
315
3
-3
5
-5
7
-5
-3
1
-
Spindle error
1
-2
3
-2
4
-3
-2
1
=
Component error
2
-1
2
-3
3
-2
-1
0