AUTOMOTIVE ENGINE VALVES
[EIRI/EDPR/1120] J.C. 9766
INTRODUCTION
The inlet valve is used to allow the income charge into the engine during the suction stroke. Exhaust valve used to allow the exhaust gases out of the engine during exhaust stroke. Both the valves close the combustion chamber during the rest of the cycles.
The valve movement is constrained by a valve guide. The seat inserts provide the seating surface for the valves to seal the combustion chamber. The opening and closing of the valves are controlled according to the valve timing by the camshaft, which gets drive from the crankshaft.
The valve train components and the mechanical load for the inlet and exhaust valves remains similar whereas the operating environment of both the valves differ which make the design considerations different for inlet and exhaust valves. The inlet valve is always cooled by the incoming charge in the inlet port so it operates at a lesser temperature. The exhaust valve is always surrounded by the hot gases and hence operates at a high temperature. The design department considers the above functional requirements during the design of valves.
The valves are manufactured through forging, Heat treatment and machining route. High precision dimensions like stem diameter, Seat height and seat Runout are maintained through the grinding process.
Poppet valves are used in most piston engines to open and close the intake and exhaust ports in the cylinder head. The valve is usually a flat disk of metal with a long rod known as the valve stem attached to one side.
The stem is used to push down on the valve and open it, with a spring generally used to return it to the closed position when the stem is not being depressed. At high revolutions per minute (RPM), the inertia of the spring makes it too slow to return the valve to its seat between cycles, leading to 'valve float'. In this situation desmodromic valves are used which, being closed by a positive mechanical action instead of by a spring, are able to cycle at the high speeds required in, for instance, motorcycle and auto racing engines.
The engine normally operates the valves by pushing on the stems with cams and cam followers. The shape and position of the cam determines the valve lift and when and how quickly (or slowly) the valve is opened. The cams are normally placed on a fixed camshaft which is then geared to the crankshaft, running at half crankshaft speed in a four-stroke engine. On high-performance engines, the camshaft is movable and the cams have a varying height, so by axially moving the camshaft in relation with the engine RPM, also the valve lift varies.
COST ESTIMATION
Plant Capacity 50,000 Engine Valve/Day
Land & Building (2000 sq.mt.) Rs. 2.09 Cr
Plant & Machinery Rs. 41.21 Lac
Working Capital for 3 Months Rs. 14.00 Cr
Total Capital Investment Rs. 16.79 Cr
Rate of Return 99%
Break Even Point 24%
CONTENTS
INTRODUCTION
VALVE POSITION
USES
B.I;S. SPECIFICATIONS
MARKET SURVEY
INDUSTRY SNAPSHOT
ORGANIZATION AND STRUCTURE
CURRENT CONDITIONS
AMERICA AND THE WORLD
RESEARCH AND TECHNOLOGY
SEGMENT TOTALS, RANKED BY FEB UNIT SALES
TOP 20 VEHICLES, CURRENT MONTH'S SALES
INTERNATIONAL DEVELOPMENTS AND TRADE
CHINA
JAPAN
SOUTH KOREA
MANUFACTURING PROCESS
MATERIAL SELECTION
VALVE
CRITERIA OF EXHAUST VALVE
STAINLESS STEELS ARE COMMONLY DIVIDED INTO FIVE GROUPS:
TABLE BELOW ARE THE PROPERTIES OF SAF 2507® (UNS S32750)
VALVE SEAT INSERT
CRITERIA FOR MATERIAL SELECTION OF ENGINE VALVE SEAT
INSERT
EXTRUSION
FRICTION WELDING
UPSETTING
FORGING
HEAT TREAMENT
STELLITE DEPOSITION
HEAD DIAMETER FACING
GROOVE CNC TURNING
TIP HARDENING
NECK PROFILE TURNING
SEAT GRINDING
SURFACE FINISHING
ALTERNATIVE PROCESS
ALTERNATIVE PROCESS
VALVE LENGTH CALCULATIONS
PRODUCTION
ONE-PIECE-FORGED VALVES
BIMETALLIC FORGED VALVES
HARD CHROME PLATE
TITANIUM VALVES:
SUPER ALLOY:
HOLLOW STEM VALVES:
COMPETITION PLUS SODIUM FILLED HOLLOW STEM VALVES
TITANIUM COMPETITION VALVES
MANUFACTURING PROCESS OF FLOW PROCESS CHART
PLANT LAYOUT
AUTOMOTIVE VALVES
STAINLESS STEEL RODS
CENTRELESS GRINDING MACHINE
DUPLEX GRINDER
AUTOMATIC LATHES
HEAT TREATMENT FURNACE
WASHING TANKS
BENCH GRINDER
BENCH DRILLING MACHINE
BRAZING EQUIPMENTS
CHAIN PULLEY
HARDNESS TESTING MACHINE
METALLURGICAL MICROSCAPIC MACHINE
ULTRASOUND MACHINE
MEASURING EQUIPMENT
D.G. SETS
ELECTRICAL POWER
UPSET MACHINES
APPENDIX – A:
01. PLANT ECONOMICS
02. LAND & BUILDING
03. PLANT AND MACHINERY
04. OTHER FIXED ASSESTS
05. FIXED CAPITAL
06. RAW MATERIAL
07. SALARY AND WAGES
08. UTILITIES AND OVERHEADS
09. TOTAL WORKING CAPITAL
10. TOTAL CAPITAL INVESTMENT
11. COST OF PRODUCTION
12. TURN OVER/ANNUM
13. BREAK EVEN POINT
14. RESOURCES FOR FINANCE
15. INSTALMENT PAYABLE IN 5 YEARS
16. DEPRECIATION CHART FOR 5 YEARS
17. PROFIT ANALYSIS FOR 5 YEARS
18. PROJECTED BALANCE SHEET FOR (5 YEARS)
