subject: Types Of Fuel Injector [print this page] Open Injector: Open Injector:
Open type is the most common type used earlier days. In injection system, fuel from the tank goes to the combustion chamber, via pump. Pump increases pressure, so that it converts in very fine particles. Fine particles evaporate more quickly and produced more power inside the combustion chamber. During the injection, the actual combustion starts when the pressure, in the fuel is more than the pressure inside the combustion chamber. If the pressure is below the pressure inside the engine, non return valve closes the passage, from where it enters. Closing the passage may stop the injection process completely. Delivery pipe, used earlier days, is short due to the space consideration inside the engine. This system is totally depends upon the diameter and length of the delivery pipe, so there is pre ignition and after burner problems due to the open type. So now days, cars are equipped with close type having no disadvantages listed in the case of open type.
Close Injector:
In this type hydrostatic pressure is taken into consideration for the opening and closing of the nozzle. There is a spring in the valve. It is open and close according to the hydrostatic pressure. When the hydrostatic pressure, available at the valve, is greater than spring force, the valve opens. Opening of the valve also opens the passage to the nozzle. When the value of the hydrostatic pressure goes below some value, valve close again and there is no supply to the combustion chamber.
Close type used now days, along with the sensors and it can react rapidly to changing inputs. It is also very sensitive to the sudden acceleration and deceleration of the throttle. This increases power output and performance of the engine as well as savings economy. Due to these advantages, close type are widely used now days.
Types of Nozzle
1.Single Hole: In this type, there is only a single hole at the center of the injector. Fuel is injected into the combustion chamber through this hole. The direction of fuel is vertically downward.
2.Multi Hole: In this type, there is more than one hole at the tip of the injector. The numbers of holes at the tip is depends upon the many factors like size of the engine, power output of the engine. These types are widely used now days. It savings the fuel thereby increasing the power output.
