The function of the rocker arm of the automobile engine is to change the direction of the movement of the push rod, push or release the valve, and make the valve open or close, thereby controlling the operation of introducing the combustible mixer into the cylinder.
The function of the rocker arm of the engine is to introduce the combustible mixture (or fresh air) into the cylinder, and then compress the combustible mixture (or fresh air) entering the cylinder, and ignite the combustible mixture (or inject diesel into the cylinder at high pressure) Form a combustible mixture and ignite), the combustible mixture is ignited and burned, the expansion pushes the piston down to perform external work, and finally discharges the burned exhaust gas.
The valve rocker arm is a double-arm lever, with the rocker shaft as the fulcrum, and the two arms are unequal in length. The end of the short arm is processed with a threaded hole for screwing in the valve clearance adjustment screw. The end of the long arm is processed into a circular arc surface, which is the working surface for pushing the valve.
The rocker arm seat is a part of the intake and exhaust mechanism in the overhead valve engine. The intake and exhaust mechanism is composed of camshaft, tappet, rocker arm, rocker shaft, rocker seat, valve, valve spring and other parts. The opening and closing of the valve is completed by the action of the tappet and the rocker arm. The rocker arm is installed on the rocker arm seat through the rocker shaft. One end is driven from the camshaft through the tappet, and the other end is pressed against the valve stem together with the spring. The function controls the opening and closing of the valve.
The valve rocker arms need to be connected by a metal connecting rod, and the cam lifts the connecting rod to push the rocker arm to realize the opening and closing of the valve. But too high rotation speed can easily cause the ejector pin to break, so this design is mostly used in engines with large displacement, low rotation speed and high torque output. The overhead camshaft can omit the ejector rod, which simplifies the transmission mechanism from the camshaft to the valve, and is more suitable for the power performance of the engine at high speed. The overhead camshaft is widely used.