The diaphragm type petrol pump is a representative of a mechanical gasoline pump for a carburetor type engine, which is generally driven by an eccentric on a camshaft. Its working condition is:
1 When the oil-absorbing camshaft rotates, when the eccentric wheel moves the rocker arm and pulls down the pump film pull rod, the pump film drops, and suction is generated. The gasoline is sucked out from the fuel tank, and passes through the oil pipe, the gasoline filter, and the oil of the gasoline pump. room.
2 Pump oil When the eccentric wheel rotates through a certain angle and no longer pushes the rocker arm, the pump membrane spring stretches, the top pump membrane rises, and the gasoline is pumped from the oil discharge valve to the floater chamber of the carburetor.
The diaphragm type gasoline pump is characterized by a simple structure, but due to the heat of the engine, special attention is paid to ensuring the performance of the pump oil at high temperatures and the durability of the diaphragm of the rubber material to heat and oil.
Generally, the maximum fuel supply of a gasoline pump is 2.5 to 3.5 times larger than the maximum fuel consumption of a gasoline engine. When the pump oil amount is greater than the fuel consumption and the carburetor float chamber needle valve is closed, the pressure in the oil pump oil discharge line is increased, and the oil pump is reacted to shorten or stop the diaphragm stroke.