What is the function of the valve mechanism? What parts are it made of

The function of the valve mechanism is to suck the combustible mixture into the cylinder in time and discharge the exhaust gas in the cylinder in time to ensure the normal operation of the engine. The valve mechanism is a control mechanism for the intake process and exhaust process of the engine, and its function is to open and close the intake and exhaust valves on time in accordance with the normal working order of the engine, so that fresh air or combustible mixture enters the cylinder and discharges the exhaust gas after combustion from the cylinder. The gas distribution mechanism should have enough gas circulation area, and ensure that the intake and exhaust holes are opened and closed in a timely manner, so that the exhaust gas can be fully discharged cleanly, and the fresh combustible mixture should be sucked in as much as possible.

Generally, the engine of the automobile adopts a valve-type valve mechanism, which is mainly composed of a valve group and a valve transmission group. The valve group includes valves, valve guides, valve seats and valve springs and other parts, and some intake valves are also equipped with valve rotation mechanisms, and the valve group should ensure the tightness of the valves to the cylinder. The valve transmission group mainly includes camshaft, timing gear, tappet and its duct, push rod, rocker arm and rocker shaft, etc., and its function is to make the intake and exhaust air according to the time specified in the gas distribution phase to open and close, and ensure that there is enough opening.

The working principle of the valve mechanism: valve opening: when the working cycle of the cylinder needs to open the valve for air exchange, the camshaft is driven to rotate by the crankshaft through the timing gear, so that the cam protrusion part on the camshaft is pushed to swing through the tappet, push rod and adjustment screw, and the other end of the rocker arm pushes down to open the valve, and at the same time makes the spring further compressed.

Valve closing: When the apex of the raised part of the cam is turned past the tappet, the valve gradually decreases in opening under the action of its spring tension until it finally closes, and the intake or exhaust process is over. During compression and power stroke, the valve is tightly closed under the action of spring tension, so that the cylinder is closed.

Because the four-stroke engine completes a working cycle, the crankshaft rotates twice, and each cylinder only intakes and exhausts once, that is, the camshaft only needs to rotate once, so the transmission ratio of the crankshaft to the camshaft is 2:1.

The function of the valve mechanism is to open and close the intake and exhaust valves regularly according to the working sequence of the engine and the requirements of the working cycle of each cylinder, and make the combustible mixture (gasoline engine) in the intake stroke.

Or air (diesel) enters the cylinder, and the exhaust gas after combustion is discharged from the cylinder during the exhaust stroke. The valve train is usually composed of two parts: the valve group and the valve transmission group, and the valve train is composed of parts such as intake, exhaust valves, valve guides, valve seats and valve springs. The valve drive group consists of a camshaft.

Rocker shaft, rocker arm, push rod, tappet and timing gear wheel, etc.

Composition of the valve mechanism:

It consists of two parts: a valve train and a valve train train.

The valve group includes valves, valve seats, valve guides, valve springs, spring seats and lock plates, etc.;

The valve transmission group includes timing gears, camshafts, tappets, push rods, adjustment screws, rocker arms, rocker arm shafts, etc.

The role of the valve mechanism:

According to the engine firing sequence and the requirements of the working cycle of each cylinder, the intake and exhaust valves are opened and closed regularly, so that fresh gas can enter the cylinder in time and exhaust gas can be discharged out of the cylinder in time.

Brief introduction of the valve mechanism:

The engine valve mechanism (internal combustion engine valve mechanism) is in accordance with the requirements of the working cycle and ignition sequence carried out in each cylinder of the engine, and regularly opens and closes the intake and exhaust valves of each cylinder, so that the fresh combustible mixture (gasoline engine) or air (diesel engine) can enter the cylinder in time, and the exhaust gas can be discharged from the cylinder in time. During the compression and power strokes, the valve is closed to ensure that the combustion chamber is sealed.

Requirements for the valve mechanism:

The requirements of the valve mechanism are that the structural parameters and forms are conducive to reducing the intake and exhaust resistance, and the opening time and continuous opening time of the intake and exhaust valves are more appropriate, so that the intake and exhaust are as adequate as possible, so as to obtain greater power torque and emission performance.

The degree to which the cylinder is filled with fresh mixture or air is expressed in terms of inflation efficiency. The higher the inflation efficiency, the more fresh air or the mass of dyeable mixture entering the cylinder, the more heat that may be emitted by the combustion mixture, and the more power the engine will have. For an engine with a certain volume (V), the mass is related to the T and P at the end of the intake air, and the lower the T and P of the intake air, the greater the intake mass and the higher the charging efficiency.

However, due to the resistance caused by the intake system to the gas, the pressure in the cylinder at the end of the intake decreases, and because of the residual high-temperature exhaust gas in the previous round of circulation, the temperature of the gas at the end of the intake gas rises, and the mass of the actual incoming gas is always less than the mass of the cylinder gas filled in the general tension state. In other words, the inflation efficiency is always less than 1. Generally.

The engine valve mechanism (internal combustion engine valve mechanism) is in accordance with the requirements of the working cycle and ignition sequence carried out in each cylinder of the engine, and regularly opens and closes the intake and exhaust valves of each cylinder, so that the fresh combustible mixture (gasoline engine) or air (diesel engine) can enter the cylinder in time, and the exhaust gas can be discharged from the cylinder in time. During the compression and power strokes, the valve is closed to ensure that the combustion chamber is sealed. All kinds of valve trains can be divided into two parts: valve group and valve transmission group.

The valve train includes the valve and the parts associated with it, and its composition is basically independent of the form of the valve train. The valve train is all the parts from the timing gear to the valve action, and its composition varies depending on the form of the valve mechanism, and its function is to drive the valve to open and close at a regular time. The valve train includes parts such as valves, valve guides, valve seats and valve springs.

Some intake valves are also equipped with a valve rotation mechanism, and the valve group should ensure the tightness of the valve to the cylinder, and the valve group.

The function of the valve mechanism is to open and close the intake and exhaust valves of each cylinder regularly in accordance with the requirements of the working cycle and firing sequence carried out in each cylinder of the engine, so that the fresh charge can enter the cylinder in time and the exhaust gas can be discharged from the cylinder in time; During the compression and expansion strokes, the sealing of the combustion chamber is ensured.

It is mainly composed of two parts: valve actuation group and valve train.

Valve actuation group: The valve actuation group is all the parts from the timing gear to the valve action. It is mainly composed of timing gears, camshafts, valve tappets, push rods, adjusting screws and lock nuts, rocker arms, rocker arm shafts, rocker arm shaft brackets, etc.

Its function is to drive the valve to open and close at regular intervals.

Valve group: It is mainly composed of valve locks, valve spring seats, valve springs, valves, valve guides, valve seats, etc. Its function is mainly to maintain the closure of the valve.

Precautions for engine valve mechanism.

When the rocker shaft of the engine is assembled, the oil groove is downward, and there are positioning bolts on the middle rocker shaft support to position the rocker shaft, and the oil outlet hole on the rocker shaft should be biased to the side of the adjustment bolt on the rocker arm, and during the operation of the engine, the oil flows along the matching gap between the rocker arm and the rocker shaft, and lubricates each pair of friction pairs.

When installing the rocker mechanism, the valve adjustment bolt can be loosened first (so as not to bend the push rod when tightening the support bolt), and then the bolt and nut can be tightened evenly from the middle to both ends.

The valve train is usually composed of two parts: the valve train and the valve transmission group.

1.Valve train.

It is composed of intake valves, exhaust valves, valve guides, valve seats and valve springs.

2.Valve train pack.

It is composed of timing belt or timing chain, camshaft, rocker arm shaft, rocker arm, push rod, tappet and timing gear, etc.

The function of the engine valve mechanism is to open and close the intake and exhaust valves regularly according to the working sequence of the engine and the requirements of the working cycle of each cylinder, so that the combustible mixture (gasoline engine) or air (diesel engine) enters the cylinder in the intake stroke, and the exhaust gas after combustion is discharged out of the cylinder in the exhaust stroke.

In order to ensure that some of the gas inside can enter the cylinder, in order to exhaust the useless gas inside, it is composed of springs, valves, guides, gears, tappets, and these.

The combustible mixture can be sucked into the cylinder in time, and the exhaust gas inside can be discharged, so that the engine can work better, and the main components that make it include valves, guide valves, valve mains, and springs.

In order to allow some gas to enter the cylinder duct, and some exhaust gas is exhausted, it is composed of valves, exhaust valves, cylinders, gas valves, and switches.

It is mainly to inhale and expel gases. This will ensure that the engine is working properly. Including valves, tappets, push rocker swing arm swivel, push rods, springs and more.

The functions and components of the valve mechanism are as follows:

1.The function of the gas distribution mechanism:

The engine valve mechanism (internal combustion engine valve mechanism) is in accordance with the requirements of the working cycle and ignition sequence carried out in each cylinder of the engine, and regularly opens and closes the intake and exhaust valves of each cylinder, so that the fresh combustible mixture (gasoline engine) or air (diesel engine) can enter the cylinder in time, and the exhaust gas can be discharged from the cylinder in time. During the compression and power strokes, the valve is closed to ensure that the combustion chamber is sealed.

2.Component composition of the valve mechanism:

Both the intake and exhaust valves are hung upside down on the cylinder head. The valve group includes valves, valve guides, valve seats, spring seats, valve springs, lock plates and other parts; The valve drive group generally consists of a rocker arm, rocker shaft, push rod, tappet, camshaft and timing gear.