26-12-2012, 02:27 PM
Study the designs of cam shafts used in various automobiles. Analyze the cam surfaces of the cam shaft use in Suzuki 800cc engine.
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ABSTRACT
The main objective of this project is to Study the designs of cam shafts used in various automobiles and to analyze the cam surfaces of the cam shaft use in Suzuki 800cc engine.
Camshaft is an important component used in engines . The camshaft is an apparatus often used in piston engines to operate poppet valves. The camshaft uses lobes to open valves as it rotates; springs are utilized to return the valves to the closed position. It consists of a cylindrical rod running the length of the engine with a number of lobes (cams) protruding from it. Ultimately, the camshaft controls the timing for intake and exhaust of each piston. Timing is varied with different cam profiles, arrangement of cams on the shaft, or using variable valve timing technology.
Suzuki Mehran 800CC has 4 strokes, 3 cylinder inline engines. It has piston displacement of 796cc, maximum power out is 29.4Kw (39.4hp) at 5500rpm and maximum torque of 59Nm at 3000rpm.
The other part of our project was to design the camshaft of Suzuki 800cc and analyze its surfaces. We use Pro-E software for designing and analysis as guided by our instructor.
IC ENGINES
I.C engines are those in which combustion takes place inside the engine. Initially the engines were made so that ignition took place externally but then as this field of knowledge began to develop present form of engines, i.e. internal combustion engines were made.
Engines are now-a-days categorized as two main types. These are:
1 - Compression ignition engines.
2 - Spark ignition engines.
CAMSHAFT
The camshaft uses lobes (called cams) that push against the valves to open them as the camshaft rotates; springs on the valves return them to their closed position. This is a critical job, and can have a great impact on an engine's performance at different speeds.
INTRODUCTION:
A straight, gear-driven shaft that contains lobes used to operate the intake and exhaust valves of a reciprocating engine. The camshaft is geared to the crankshaft in such a way that valves close and open at the correct time relative to the position of the piston in the cylinders.camshaft made of cast iron or forged steel with one cam per valve is used to open and close the valves . the cam surfaces are hard made to obtain enough life under hard working conditions.
The camshafts are driven from the crankshaft
by camshaft drivers that may be gear , belt,or chain. Combustion gases in four-stroke engines are
controlled by the valve mechanism,a complex
structure, often referred to as a Valve train ,
of which the camshaft is an integral part .The
valve train can determines the overall engine
performance.
The valve train consists of a valve operating
mechanism and a camshaft drive mechanism.
The valve operating mechanism transforms
rotation of the crankshaft into reciprocating
motion in the valves.The valves front enter into
the Combustion chamber and are pushed back
by the reactive force of the Valve spring .
Uses
In internal combustion engines with pistons, the camshaft is used to operate poppet valves. It then consists of a cylindrical rod running the length of the cylinder bank with a number of oblong lobes protruding from it, one for each valve. The cams force the valves open by pressing on the valve, or on some intermediate mechanism as they rotate.
Camshaft Basics
The key parts of any camshaft are the lobes. As the camshaft spins, the lobes open and close the intake and exhaust valves in time with the motion of the piston. It turns out that there is a direct relationship between the shape of the cam lobes and the way the engine performs in different speed ranges.
Overhead camshaft
Overhead camshaft, commonly abbreviated to OHC, valvetrain configurations place the engine camshaft within the cylinder heads, above the combustion chambers, and drive the valves or lifters in a more direct manner compared to overhead valves (OHV) and pushrods.
Compared to OHV pushrod (or I-Head) systems with the same number of valves the reciprocating components of the OHC system are fewer and have a lower total mass. Though the system that drives the cams may become more complex, most engine manufacturers easily accept that added complexity in trade for better engine performance and greater design flexibility. Another performance advantage is gained as a result of the better optimized port configurations made possible with overhead camshaft designs. With no intrusive pushrods the overhead camshaft cylinder head design can use straighter ports of more advantageous crossection and length.
Variable Valve Timing
There are a couple of novel ways by which carmakers vary the valve timing. One¬ system used on some Honda engines is called VTEC.VTEC (Variable Valve Timing and Lift Electronic Control) is an electronic and mechanical system in some Honda engines that allows the engine to have multiple camshafts. VTEC engines have an extra intake cam with its own rocker, which follows this cam. The profile on this cam keeps the intake valve open longer than the other cam profile.
CONCLUSIONS
Cam profile design and cam design for manufacture is a specialist topic. With the advent of mathematically complex but accurate, user-friendly and highly visual computer software it, as with valve lift profile design, can be professionally executed by the engineer who normally designs the powerproducing cylinder-head components of the engine. Don’t over-cam your engine. Choose your cam for the correct application. Consider! Fit a milder cam and increase your power by 10 BHP at 3500 rpm.
Remember! You get this 10 HP every time you accelerate through 3500 rpm. Multiply this by 10 HP each time you drive through 3500 rpm then deduct the times you reach 7500 rpm.
I’m sure you will find more horsepower on the 3500 rpm side than the 7500 rpm calculation
[attachment=45273]
ABSTRACT
The main objective of this project is to Study the designs of cam shafts used in various automobiles and to analyze the cam surfaces of the cam shaft use in Suzuki 800cc engine.
Camshaft is an important component used in engines . The camshaft is an apparatus often used in piston engines to operate poppet valves. The camshaft uses lobes to open valves as it rotates; springs are utilized to return the valves to the closed position. It consists of a cylindrical rod running the length of the engine with a number of lobes (cams) protruding from it. Ultimately, the camshaft controls the timing for intake and exhaust of each piston. Timing is varied with different cam profiles, arrangement of cams on the shaft, or using variable valve timing technology.
Suzuki Mehran 800CC has 4 strokes, 3 cylinder inline engines. It has piston displacement of 796cc, maximum power out is 29.4Kw (39.4hp) at 5500rpm and maximum torque of 59Nm at 3000rpm.
The other part of our project was to design the camshaft of Suzuki 800cc and analyze its surfaces. We use Pro-E software for designing and analysis as guided by our instructor.
IC ENGINES
I.C engines are those in which combustion takes place inside the engine. Initially the engines were made so that ignition took place externally but then as this field of knowledge began to develop present form of engines, i.e. internal combustion engines were made.
Engines are now-a-days categorized as two main types. These are:
1 - Compression ignition engines.
2 - Spark ignition engines.
CAMSHAFT
The camshaft uses lobes (called cams) that push against the valves to open them as the camshaft rotates; springs on the valves return them to their closed position. This is a critical job, and can have a great impact on an engine's performance at different speeds.
INTRODUCTION:
A straight, gear-driven shaft that contains lobes used to operate the intake and exhaust valves of a reciprocating engine. The camshaft is geared to the crankshaft in such a way that valves close and open at the correct time relative to the position of the piston in the cylinders.camshaft made of cast iron or forged steel with one cam per valve is used to open and close the valves . the cam surfaces are hard made to obtain enough life under hard working conditions.
The camshafts are driven from the crankshaft
by camshaft drivers that may be gear , belt,or chain. Combustion gases in four-stroke engines are
controlled by the valve mechanism,a complex
structure, often referred to as a Valve train ,
of which the camshaft is an integral part .The
valve train can determines the overall engine
performance.
The valve train consists of a valve operating
mechanism and a camshaft drive mechanism.
The valve operating mechanism transforms
rotation of the crankshaft into reciprocating
motion in the valves.The valves front enter into
the Combustion chamber and are pushed back
by the reactive force of the Valve spring .
Uses
In internal combustion engines with pistons, the camshaft is used to operate poppet valves. It then consists of a cylindrical rod running the length of the cylinder bank with a number of oblong lobes protruding from it, one for each valve. The cams force the valves open by pressing on the valve, or on some intermediate mechanism as they rotate.
Camshaft Basics
The key parts of any camshaft are the lobes. As the camshaft spins, the lobes open and close the intake and exhaust valves in time with the motion of the piston. It turns out that there is a direct relationship between the shape of the cam lobes and the way the engine performs in different speed ranges.
Overhead camshaft
Overhead camshaft, commonly abbreviated to OHC, valvetrain configurations place the engine camshaft within the cylinder heads, above the combustion chambers, and drive the valves or lifters in a more direct manner compared to overhead valves (OHV) and pushrods.
Compared to OHV pushrod (or I-Head) systems with the same number of valves the reciprocating components of the OHC system are fewer and have a lower total mass. Though the system that drives the cams may become more complex, most engine manufacturers easily accept that added complexity in trade for better engine performance and greater design flexibility. Another performance advantage is gained as a result of the better optimized port configurations made possible with overhead camshaft designs. With no intrusive pushrods the overhead camshaft cylinder head design can use straighter ports of more advantageous crossection and length.
Variable Valve Timing
There are a couple of novel ways by which carmakers vary the valve timing. One¬ system used on some Honda engines is called VTEC.VTEC (Variable Valve Timing and Lift Electronic Control) is an electronic and mechanical system in some Honda engines that allows the engine to have multiple camshafts. VTEC engines have an extra intake cam with its own rocker, which follows this cam. The profile on this cam keeps the intake valve open longer than the other cam profile.
CONCLUSIONS
Cam profile design and cam design for manufacture is a specialist topic. With the advent of mathematically complex but accurate, user-friendly and highly visual computer software it, as with valve lift profile design, can be professionally executed by the engineer who normally designs the powerproducing cylinder-head components of the engine. Don’t over-cam your engine. Choose your cam for the correct application. Consider! Fit a milder cam and increase your power by 10 BHP at 3500 rpm.
Remember! You get this 10 HP every time you accelerate through 3500 rpm. Multiply this by 10 HP each time you drive through 3500 rpm then deduct the times you reach 7500 rpm.
I’m sure you will find more horsepower on the 3500 rpm side than the 7500 rpm calculation