SHRI G.S.
INSTITUTE OF TECHNOLOGY AND SCIENCES
Department of Industrial and Production Engineering
Industrial Training (IP-33452)
Project Name: Inspection of Piston and Piston Rings
At: Volvo Eicher Commercial Vehicles Ltd.
Submitted by: Submitted to:
Kunal Soni Mr.Kumar Rohit
3rd Year (5th Semester) Mr.Krishnakant Dhakad
Enrollment:0801IP221045 Ms.Neha Patkar
Mrs.Mahima Hardiya
CONTENTS
1. Introduction
1.1. Company profile
1.2. Manufactured components
1.3. Domain
2. Profile of the department
2.1. Departments
2.2. Key objectives of the project
2.3. Problem statement
3. Processes of manufacturing department
3.1. Introduction to piston and piston rings
3.2. Piston ring assembly
3.3. Piston ring fixing
3.3.1. Issues faced and details
3.4. Methodologies approach adopted
3.5. Observations
4. Conclusion
4.1. Results obtained
4.2. Discussions
5. Key learnings gained
6. References
7. DTR Report
1.INTRODUCTION
1.1 Company’s Profile
1. Eicher has a joint venture with Sweden’s AB Volvo, Volvo Eicher Commercial
Vehicles Limited (VECV), which has pioneered the modernisation of commercial
vehicles in India and other developing countries.
2. VE Powertrain(VEPT) is the most technologically advanced engine manufacturing
plant in India. VECV set it up in Pithampur, Madhya Pradesh.
3. The current capacity stands at 75,000 units which is scalable to 100,000 with
additional investments. VEPT is a global hub for meeting the medium-duty automotive
engine requirements of Volvo Group globally for five- and eight-litre engines.
4. The base engines for Euro VI requirements of Volvo Group are being supplied to their
plant in Venissieux, France.
5. Some salient features of the manufacturing facility are:
5.1. Machining cylinder block and cylinder head for 4 and 6 cylinder engines. In-process
measurement for critical operations.
5.2. SPMs with work changer – a first time concept in India to minimize part change time
in machining.
5.3. Engine assembly line designed for high diversity meeting European quality
standards. First time right manufacturing with In-Process verification and multiple
tests before delivering the engine to the customer.
5.4. AGVs for final assembly. Frugal engineering – developed in India, based on custom
proto build. Hybrid concept with wireless charging equipped with safety features
recommended by EU standards.
5.5. Smart cell for cylinder head assembly. First to adopt the concept in Volvo Group.
5.6. System enabled (Pull based) minimum material movement. Repacking under a
controlled environment.
1.2 Manufactured Components
1. Light-duty commercial trucks
1.1. Gross vehicle weight range(GVWR) ranges from 0-14000 pounds.
1.2. Many light-duty trucks aren’t actually used for commercial purposes.
1.3. Light Duty trucks come with the new-gen Quad 100 Series and the excellent Lin 4500
series,.These series are suitable for a variety of applications from 4.9 ton to 17.75 ton GVW.
2. Medium-duty commercial trucks
2.1. GVWR: 14001-26000 pounds.
2.2. Medium Duty trucks comprises the new-gen Pro 2000 Series and the advanced Pro 3000
series, designed keeping in mind both the owner's and driver's needs. These series are
suitable for a variety of applications from 4.9 ton to 17.75 ton GVW.
3. Heavy duty commercial trucks
3.1. GVWR:26001– +33000 pounds.
3.2. The new range of BS VI Eicher Pro Heavy Duty haulage trucks and tractors, available
from 18.5-55 tonne GVW, is designed and developed to provide an unparalleled business
advantage by maximizing product performance right through the life cycle of the vehicles
and minimizing the cost of operations.
4. Buses
All-new Eicher BSVI Bus Range, a cutting-edge collection of next-generation buses
meticulously designed to meet the diverse needs of modern transportation. Engineered for
outstanding efficiency, these buses are tailored to deliver maximum fuel economy,
significantly reducing operational costs while boosting overall profitability for businesses.
With a perfect blend of innovation, reliability, and performance, the Eicher BSVI Bus Range
sets a new benchmark in the industry, redefining standards.
6. IC Engine
6.1. MDE 5L Engine
6.2. MDE 8l Engine
7. Eicher Engineering components
7.1. Gears and shafts
7.2. Transmission assembly
7.3. Auxiliary aggregates
7.4. Automotive components
1.3. Domain
The internship was conducted in the Production domain, focusing on the manufacturing
processes of medium-duty engines with displacements of 5 and 8 liters. This domain
involves a systematic approach to engine production, emphasizing precision, efficiency, and
quality assurance.
Key activities include machining critical components like cylinder blocks and cylinder
heads, assembly of engine parts namely piston and piston rings,shell bearing,fuel
pump,crankshaft,camshaft, fuel injector spray, cooling jet, and rigorous quality checks to
ensure adherence to industry standards.
The domain integrates advanced manufacturing technologies and lean production principles
to optimize workflows, minimize waste, and enhance productivity. This experience provided
a comprehensive understanding of production planning, process optimization, and the critical
aspects of engine manufacturing.
2.Profile of the department
1. Machine Shop
1. Cylinder Head and Cylinder Block Roles: The cylinder head encloses combustion
chambers, supports valves, and aids thermal insulation, while the cylinder block ensures
stability, lubrication, and cooling for the engine.
2. Material and Design: Cylinder heads are made from iron alloys or aluminum for thermal
conductivity and stress resistance. Cylinder blocks use durable materials tailored to engine
capacity and application.
3. Key Features: Cylinder heads manage combustion, airflow, and coolant circulation, while
cylinder blocks house oil and water galleries for lubrication and cooling.
4. Production Process: Separate production lines with multiple stations handle cylinder head
and block manufacturing, ensuring process accuracy and product quality through controlled
operations.
5. Quality Control: Each station (coded as OP) involves supervisors, operators, and machine-
generated control plans to meet company and consumer standards.
Figure 1Machined cylinder heads
Figure 2 Machining of cylinder head
Figure 3 Machining of the Engine block
2. Basic Line
The Basic Line at VEPT produces LONGBLOCK engines, integrating components from the
Block, Piston, and Head lines. These engines are moisture-protected post-production for
export. MES systems ensure process accuracy, tracking, and quality control via detailed
operation records.
3. Block Line
The Block Line assembles engines by integrating pistons and cylinder heads using robotic
arms and automated systems. MES records every operation, ensuring precision and defect
analysis.
4. Piston Line
The Piston Line comprises four stations assembling pistons, con rods, snap rings, and piston
rings using robotic arms and semi-automated systems. Precise handling avoids vibrations,
ensuring alignment and accuracy. Final pistons are transferred to the Block Line for
integration.
5. Head Line
The Head Line assembles fully loaded cylinder heads with injectors, valve guides, and
camshafts. Advanced robotic cells ensure precision. Completed heads undergo inspection
and are transferred to the Block Line for final integration after placing a gasket in between.
6. Block Line
The Block Line assembles cylinder heads and integrates key components like valve bridges
and fuel pumps. It features both manual and automated stations, including precision robotic
arms for piston placement. Final quality checks at Quality Gate 1 ensure defect-free
longblocks, which are stored or sent to the Timing Gear (TG) Line.
7. TG Line
The TG Line assembles Extended LongBlocks (ELBs) by adding timing gears and flywheel
assemblies to longblocks. It includes five stations, with a quality check at Quality Gate 2 to
ensure defect-free output. ELBs are packaged for export or moved to the Final Line for
further assembly into Complete Build Units (CBUs).
8. Final Line
The Final Line completes CBUs by assembling peripherals like oil pumps, alternators,
sensors, and piping. Using AGVs and kitting trolleys for part delivery, the manual stations
ensure precision. After Quality Gate 3.
2.1.Project objectives
To perform inspection on piston rings by-
1.Studying of different piston variants drawings, and calculating tolerance limits on each
vertical height of the three piston rings respectively.
2.Studying of piston rings assembly process by automation process with a robotic arm.
3.Measuring and checking the variation in vertical heights of top surface of piston with
respect to each bush(present at the bottom of the pallet) respectively.
4 To improve the manufacturing process of pistons,specifically enhancing the tolerance
range in the piston ring grooves.
2.2 Problem statement
To specify a tight tolerance limit or a tolerance range over the entire groove,while
maintaining efficiency and practice low cost manufacturing.
3.Process details and methodologies adopted:-
3.1.Introduction to Piston and piston rings
A piston is a cylindrical engine component that slides back and forth in the cylinder bore by
forces produced during the combustion process. The piston acts as a movable end of the
combustion chamber. The stationary end of the combustion chamber is the cylinder head.
Pistons are commonly made of a cast aluminum alloy for excellent and lightweight thermal
conductivity. Aluminum expands when heated, and proper clearance must be provided to
maintain free piston movement in the cylinder bore. Insufficient clearance can cause the
piston to seize in the cylinder. Excessive clearance can cause a loss of compression and an
increase in piston noise.
Piston features include the piston head, piston pin bore, piston pin, skirt, ring grooves, ring
lands, and piston rings. The piston head is the top surface (closest to the cylinder head) of the
piston which is subjected to tremendous forces and heat during normal engine operation.
A piston pin bore is a through hole in the side of the piston perpendicular to piston travel that
receives the piston pin.
A piston pin is a hollow shaft that connects the small end of the connecting rod to the piston.
The skirt of a piston is the portion of the piston closest to the crankshaft that helps align the
piston as it moves in the cylinder bore.
A piston ring is an expandable split ring used to provide a seal between the piston an the
cylinder wall. Piston rings are commonly made from cast iron. Cast iron retains the integrity
of its original shape under heat, load, and other dynamic forces. Piston rings seal the
combustion chamber, conduct heat from the piston to the cylinder wall, and return oil to the
crankcase. Piston ring size and configuration vary depending on engine design and cylinder
material.
Piston rings commonly used on small engines include the compression ring, wiper ring, and
oil ring.
A compression ring is the piston ring located in the ring groove closest to the piston head.
The compression ring seals the combustion chamber from any leakage during the
combustion process. When the air-fuel mixture is ignited, pressure from combustion gases is
applied to the piston head, forcing the piston toward the crankshaft. The pressurized gases
travel through the gap between the cylinder wall and the piston and into the piston ring
groove. Combustion gas pressure forces the piston ring against the cylinder wall to form a
seal. Pressure applied to the piston ring is
approximately proportional to the combustion gas
pressure.
A wiper ring is the piston ring with a tapered face
located in the ring groove between the compression
ring and the oil ring. The wiper ring is used to further
seal the combustion chamber and to wipe the cylinder
wall clean of excess oil. Combustion gases that pass by
the compression ring are stopped by the wiper ring.
An oil ring is the piston ring located in the ring groove
closest to the crankcase. The oil ring is used to wipe
excess oil from the cylinder wall during piston
movement. Excess oil is returned through ring
openings to the oil reservoir in the engine block. Two-stroke cycle engines do not require oil
rings because lubrication is supplied by mixing oil in the gasoline, and an oil reservoir is not
required.
3.2. Piston Ring Assembly Process
1.Securing the Connecting Rod:
1. Attachment to Pallet: The assembly line begins by securing the connecting rod to a
pallet that holds the rod cap and piston in place.
2. Big End Support: The larger end of the rod, known as the big end, is supported on the
pallet, providing stability.
3. Small End Free: The smaller end, or small end, remains unattached, allowing for the
subsequent attachment of the piston to complete the assembly.
2. Securing Piston Variants:
1. Attachment to Small End: Various piston variants are secured onto the small end of
the connecting rod.
2. Insertion of Piston Pin: Pistons are then fitted with a piston pin inserted into their
bores. This pin is crucial for connecting the piston to the connecting rod.
3. Fixing the Snap Ring (Circlip):
1. Positioning the Snap Ring: Snap rings, also known as circlips, are fixed at both sides
of the piston pin bore.
2. Securing the Piston Pin: The snap rings ensure that the piston pin remains securely in
place, preventing it from dislodging during engine operation.
4.Robotic Arm Operation:
1. Lifting the Piston Assembly: A robotic arm equipped with a gripper lifts the piston
assembly.
2. Use of LVDT Sensors: The robotic arm uses separate Linear Variable Differential
Transformers (LVDT) sensors(for each ring) to amplify the electric signals and
accurately position the piston assembly i.e.correct orientation of piston rings in the
grooves
3. Mounting Piston Rings: The robotic arm mounts piston rings, compression rings, and
oil rings onto the piston.
4. 120-Degree Placement: Each ring is placed at 120 degrees to one another. This
specific placement is essential to prevent any gas flow-by or oil leaks from the
cylinder, thereby the pressure caused by the air-fuel mixture and ensuring efficient
engine operation.
3.3. Piston Ring Fixing Process and Issues in Detail
1. Robotic Arm Operation:
a. Gripper Function: The robotic arm, known as the gripper, inputs the coordinates
from the bush in the pallet to establish a datum.
b. LVDT Sensors: The gripper locates the piston ring grooves' vertical height using
Linear Variable Differential Transformers (LVDT) sensors.
2. Datum Establishment:
a. Coordinate Input: The gripper uses the coordinates from the bush in the pallet as a
reference point or datum.
b. Imaginary Plane: The robot assumes an imaginary plane using the lowermost bush
with the least depth in a horizontal plane, considering all bushes to be in the same
plane.
3. Groove Position Detection:
a. Measuring Grooves: The robot measures the exact location of the piston ring
grooves concerning the bush to obtain the datum.
b. Plane Discrepancies: Differences in readings arise because the bushes of the pallet
are not in the same plane.
4. Issues with Groove Position:
a. Variation in Position: The variation in the plane of the bushes causes discrepancies
in the holding position of the piston.This variation arises due to continuous usage of
same set of pallets for a continuous period of time,Increment of stress in the
material,mishandling of piston palletes leading to wear in the bush.
b. Symmetry Disturbance: This leads to a disturbance in the symmetry of the piston
ring attachment as shown in figure.
3.2.1. Resulting Problems:
a. Inappropriate Ring Fixing: Due to the
disturbed symmetry, the piston rings are not
appropriately fixed in the grooves.
b. Incomplete Fitting: The rings are not completely fitted into the grooves, which
affects their performance.
3.4.Methodologies approach adopted
1. Finding vertical distances of piston assembly
Finding vertical distances of piston assembly using 2-D vernier height gauge
where bottom of pallet is taken as reference point or zero value.
The dimensions that are calculated are shown in figure.
2. Specifying tolerances
Once we get the data on height parameter, tolerances are find out with the help of
“General tolerances” set by Indian standards .Under the fine tolerance class the
value of tolerance for each vertical height is calculated separately.
3. Addition of tolerances
Tolerances are additive and hence for each vertical height in addition they are
added for positive sign and subtracted for minus sign.
4. Experimental values of tolerances are obtained
Vertical dimensions were measured of the pallet piston assembly using a 2-
height gauge and as a consequence the
data obtained for the same is as
follows:-
Figure 4:Inspection using 2-D vernier height gauge
3.4.Observations
According to the "General Tolerances" of the Indian Standards Organization in the
"fine" tolerance class, the dimensions of some pallet assemblies were found to exceed the
variation limit.
1. After analyzing the data obtained by 2-D height gauge bush were found to be
nonplanar i.e. not in the same plane.
2. Manual station was made to check the orientation of piston rings if placed correctly
in between the grooves, each ring gap at 120 degrees each.
3. Piston crown and the bush were not found parallel to each other thus not complying
with the flatness tolerance .
4. Resting surface of piston skirt was not found to be in contact with the pallet surface
as seen in the figure.
5. This could be due to excessive load on the surface which as a result have undergone
wear and tear leading to imbalance of piston on the pallet surface.
3.5.Results
Results of Analyzing Piston Assembly's Vertical Heights
1. Dimensional Accuracy: The specified tolerances can be used to compare the
measured vertical heights of the pistons, allowing the determination of whether the
components are within acceptable limits. Any deviations from the design
specifications can be identified through this comparison.
2. Quality Control Assessment: The quality of the manufacturing process can be
assessed by examining the consistency of the measured vertical heights. A high degree
of variability might indicate issues in the production process that need to be addressed.
3. Assembly Efficiency: The measurements can indicate the fit of the pistons within the
assembly, showing whether significant adjustments are required. A well-optimized
assembly process is indicated by pistons fitting well without significant adjustments,
while significant deviations might suggest the need for process improvements or
reengineering.
4. Statistical Analysis: Insights into the overall manufacturing process's stability and
control can be provided by performing a statistical analysis (e.g., mean, standard
deviation) of the measurements. Specific areas requiring attention can be pinpointed
by identifying any outliers or trends.
5. Performance Predictions: The assembly's performance can be predicted by
understanding the vertical height measurements in relation to the piston's functionality.
Potential performance issues can be indicated if the vertical heights are crucial for the
piston's sealing or movement within the cylinder.
6. Identification of Defects: Defects in the pistons or the assembly process might be
indicated by significant deviations from the expected vertical heights. These defects
can then be investigated further to determine their root causes and implement
corrective actions.
7. Process Improvements: Improvements in the manufacturing and assembly processes
can be guided by the insights gained from the measurements. This could involve
adjusting machine settings, refining assembly techniques, or enhancing quality control
measures to ensure better adherence to design specifications.
CONCLUSION
The application of Geometric Dimensioning and Tolerancing (GD&T) in the study of
robotic arms for the precise insertion of piston rings into their respective grooves has
proven to be an indispensable aspect of modern manufacturing processes. Throughout
this report, we have explored the fundamental principles of GD&T and their critical role
in ensuring the accuracy and efficiency of automated systems.
The integration of GD&T has allowed for a detailed analysis of the tolerances required
for the robotic arm to function optimally. By applying these principles, we have been
able to define and control the allowable variations in dimensions and geometry, ensuring
that the robotic arm can accurately sense and manipulate the piston rings with a high
degree of precision. This level of control is essential for maintaining the quality and
performance standards expected in the production of engine components.
KEY LEARNINGS
Key findings from this study include:
1. Enhanced Precision: The process provides a comprehensive framework for defining
This enhances the precision of piston ring insertion, reducing the risk of errors and
improving overall product quality and understanding about the concepts of
metrology such as increased knowledge about the tolerances and geometric
dimensioning and tolerancing(GD&T).
2. Improved Efficiency: By clearly specifying tolerances, GD&T helps in minimizing the
variability in component dimensions, leading to more consistent and reliable robotic
operations. This results in improved efficiency and reduced cycle times in the
manufacturing process.Concepts of industrial engineering such as time study,method
study and ergonomics are learned.
3. Data-Driven Decision Making: The use of GD&T allows for the collection and analysis
of data related to the performance of the robotic arm. This data-driven approach
helps us to take decisions based on data,logical reasoning and based on orevious
records and suggestions.
4. Increased Reliability: The application of GD&T ensures that all components fit
together as intended, reducing the likelihood of mechanical failures. This increases
the reliability and longevity of both the robotic arm and the engine components it
assembles.
In conclusion, the implementation of Geometric Dimensioning and Tolerancing in the
study of robotic arms for piston ring insertion has demonstrated significant benefits
in terms of precision, efficiency, and reliability. The ability to control and manage
tolerances through GD&T not only enhances the functionality of automated systems
but also contributes to the overall advancement of manufacturing technologies.
Future work should continue to explore the integration of GD&T with emerging
technologies to further optimize and innovate automated manufacturing processes.
REFERENCES
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3rd august,2024
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%20Dimenisoning%20and%20Tolerancing%20by%20Olaf%20Pippel%20of
%20HYDAC.pdf. Accessed on 27 august,2024
3. How a car works 2017 ”On the piston and piston rings”,
https://www.howacarworks.com/pistons, Accesed on 7 August 2024
4. https://courses.washington.edu/engr100/Section_Wei/engine/UofWindsorManual/
Piston%20and%20Piston%20Rings.htm. Accessed Dec. 5, 2024.
5. UOF Windsor manual, 2018, “On piston and piston rings”, browsed on
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Connecting%20Rod.htm. Accessed on Aug. 5, 2024.
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Accessed July 6, 2024.
