The variable intake manifold by changing the intake pipe length and cross-sectional area, to improve the efficiency of combustion, make the engine more stable at low speeds, the torque more adequate, more smoothly at high speed, a more powerful.
1. The variable intake manifold noun
The variable intake manifold by changing the intake pipe length and cross-sectional area, to improve the combustion efficiency of the engine at low speed and more smooth, more adequate torque, smoother high speed, a more powerful.
2. The variable intake manifold art
One end of an intake manifold connected with the intake valve, is connected to the rear end of the intake manifold intake resonance chamber, each cylinder has an intake manifold. The engine is running, the intake valve continuously open and close, when the valve is opened, the intake manifold air mixture into the cylinder at a constant speed through the valve, the valve closing when the gas mixture will rebound when blocked, occur again and again vibration frequency. If the intake manifold is short, clear that this frequency will be faster; if intake manifold is long, the frequency becomes relatively slow. If the oscillation frequency of the intake valve in the intake manifold of the mixture gas reaches the resonance time of opening, then the intake efficiency at this time is obviously very high. Thus variable intake manifold, to provide best engine valve at high speed and low speed.
the engine at low speeds, with long, thin intake manifold, the intake air can be increased airflow velocity and pressure strength, and so be better gasoline atomization, better combustion, improved torque. (Like the pinch flat water, the water will be more strongly) requires a lot of mixed gas of the engine at high speeds, which is the intake manifold and the crude will become short, so as to inhale more gas mixture, increasing the output power.
3. The variable intake manifold technical principle
Since the gas is a mixture of fluids having mass flow in the intake pipe in the state is changing, often using fluid engineering to optimize its internal design, for example the inner wall of the intake manifold smooth polished reduce resistanceOr to deliberately create a rough surface to create a swirling motion within the cylinder. However, the work of a car engine speed interval of up to thousands of revolutions required for each intake demand conditions are not the same, this is a great test tube for ordinary intake manifold. As a result, engineers intake manifold was developed deep – Let intake manifold “change” them.
● Variable length
2 cycles shuttle car up and down the piston 4 stroke engine is not complete a work cycle, only 1/4 of the time the intake valve opened so that the intake air causes a pulse in the intake manifold. The higher the engine speed, the shorter valve opening interval, the higher the pulse frequency. Simply put, the greater the vibration of the intake manifold.
Engineers by changing the length of the intake manifold, improved flow stream. The intake manifold is designed to be spiral snail, located in the middle of the engine block, from the gas stream enters the middle. When the engine is running at low speed 2000prm, black control valve is closed, forced air flow from the pipe into a long cylinder manifold, at this time, the intake manifold of the natural frequency is reduced to accommodate the low speed airflow. When raised to 5000 rpm for the engine rotational speed, intake frequency is increased, when the control valve is opened to bypass air flow duct directly into the cylinder lower portion, which reduces the resonance frequency of the intake manifold, the intake facilitates high speed.
● variable section
We know that the valve is set to a short-stroke low speed when open, the valve opening stroke is set to grow at high speed, which are “negative pressure “mess out of the disaster. So in addition to the valve, the intake manifold can not yet achieve the same effect
principles of fluid mechanics, the larger cross-sectional area of the pipe, the less fluid pressure;? Smaller pipe cross-sectional area, the greater the fluid pressure. For example: a child we all played tap, pinch flat front end of the pipe, the water pressure can become very large.
According to this principle, the engine needs a mechanism, the use of larger cross-sectional area of the intake manifold at high speed, intake air flow rate increase; the use of smaller cross-section in the intake manifold at low speed area, increase the intake negative pressure cylinder, a vortex can be sufficiently formed in the cylinder, so that better mixing of air and fuel.