in-process diagnostics for grinding
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In-Process Diagnostics for
Grinding Process
Case Studies
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CONFIDENTIAL
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In-Process Diagnostics
Monitoring of the grinding process:a) Wheel motor power (kW)
b) Slide Position (mm)
Signals represent the grinding process as it is
happening gives the real-time signature of
the process.
CONFIDENTIAL
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Input Transformation Output
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How does it help? Better asset utilization
Capacity Increase & Reduced cost per part By optimizing grinding cycle
Reduction of non-grinding time
Increasing wheel life
Solving process related issues
Identify and resolve process problems Burn, wheel loading, glazing, high wheel wear
Process benchmarking and machine characterization
Document the grinding process for future reference
Comparison of in-process signals between two grinding systems 2 different cycles
Same cycles, but different machine, operator, wheel, etc.
Machine characterization Axis behaviour
Deformation shapes, etc.
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How does it do it?Signals What How Why
Power +
Position
Verify the grinding program Observe variations in the process
Benchmark processes
Featurerecognition
Super-
imposition
Optimize cycle time Variation of inputs to
grinding process
Power
Optimize dressing skip
Identify features process problems
Estimate grinding system stiffness
Feature
recognition
Trending
Increase wheel life
Solve process issues
Improve consistency
Position
Check axis behaviour
Identify deformation shapes of work
Monitor element deformation
Derived
analysis
Trending
Machine
characterization
CONFIDENTIAL
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Usage Aspects:
Portable unit Can be mounted on any grinding machine
of any type
Short Setup time: Can be setup on a grinding machine
within 30 minutes
High Sampling rate: Ensures real-time data capture of the
grinding process
Modular: Different sensor specs can be easily
configured based on application
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CASE STUDIES
Examples of use of Grind-Trak
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BETTER ASSET UTILIZATION
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1. Reduction of non-value added time
CONFIDENTIAL
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0
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120
0.5
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1.5
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2.5
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3.5
0 1 2 3 4 5 6 7 8 9 10 11 12
islac
t(
)
Power(kW)
Time (sec)
OD Profile Grinding Power (kW) Displacement (mm)
Non-value
added time
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2. Reduction of grinding time (a)
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Grinding Cycle Time = 700 sec
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3.2
3.4
3.6
3.8
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0 50 100 150 200 250 300 350 400 450 500 550 600 650 700
Displacement(mm)
Power(kW)
Time (sec)
Camshaft Journal Grinding InitialPower Displacement
Steady Journals DressingDressing
Motor Rating : 7.5 kW
Machine Stiffness sufficient
Increase feed-rates
Peak power = 4 kW
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2. Reduction of grinding time (b)
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Steady Journals Dressing
Camshaft Journal Grinding After increasing feed-rates
Grinding Cycle Time = 560 sec
Peak power = 8 kW
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SOLVING PROCESS RELATED ISSUES
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1. Wheel Glazing
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Wheel glazing causing power rise (though MRR is constant)
High Power in the finishing operation indicates glazing.
Grind-Trakshows portions of the grinding cycle where the glazing takes place.
Remedial action may be taken to rectify the problem by attacking that portion of the
grinding cycle.
OD profile grinding work-material with high hardness (62 HRC)
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2. Burn
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Spike in power causing burn
Sudden spikes in power indicate potential for burning
Remedial action may be taken to rectify the problem by attacking that portion of the
grinding cycle
Crankshaft Journal Grinding
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PROCESS DOCUMENTATION ANDBENCHMARKING
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Benchmarking
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Compare grinding cycle, system stiffness, cycle time and process behaviour.
Crankshaft Journal Grinding
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Machine Characterization
Axis behaviour
Spikes generated when
there is a change in
feed-rate.
These spikes were
giving rise to step on
the component.
After Servo Motor
tuning, the spikes were
eliminated.
No more step on the
component
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SUMMARY
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Grind-Trak Sales Grind-Trak is a useful tool that helps us to
Observe what is really happening in the grinding process
Quantify parameters by measurement that were earlier not possible
Such a tool is valuable for customer relations
Optimizing the grinding system to provide value to customer (e.g.KOEL, Bosch, Texmo, etc.)
Attending to customer process related issues (BFL, HFL) As a development tool for process benchmarking (cBN OD grinding
project, Rhino project, cBN ID grinding project)
The use of such tool and the associated efforts result in
Increased customer goodwill
MGT seen as a systems solution provider than just a machine supplier Increased customer confidence
Faster customer process issue trouble shooting
More scientific approach to application engineering
Data driven approach increased customer confidence
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CONFIDENTIAL
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Grinding processThe System Approach
Ref:Subramanian K, The System Approach A strategy to survive and succeed in the Global Economy, 2000
- M Brij Bhushan, Prof. Ramesh Babu,,B.Tech Project Report - A Diagnostic Tool For In-process MonitoringOf Grinding 2012, IIT Madras.
The System Approach of looking at grinding
Finished
P
art
Operational factors Grinding cycle
Speed, feed
Depth of cut
Machine tool Structural Compliance
Kinematic Design Bearings and spindles
Work Material Geometry
Surface properties
Material properties
Tooling/ Supplies Abrasive
Coolant
Fixtures
Grinding
process Power
Displacement
Vibration
Acousticemission
Force
Temperature
Quality Form error
Dimension
accuracy
Surface
roughness
Waviness
Integrity
Process quantities
Quality parametersControl strategies
In process
monitoring Post process
monitoring