The engine is the heart of an automobile, and the oil pump is the heart of the engine. The high pressure oil pump is a key component specially used in gasoline direct injection (GDI) engines. Compared with traditional port fuel injection engines, direct injection engines are more prone to carbon deposits. Therefore, a high pressure oil pump is required to significantly increase the fuel system pressure, providing high pressure fuel to the fuel rail assembly, achieving finer atomization, truly enabling precise proportional fuel injection control and full mixing with intake air.
Function of the Preassure Oil Pump:
The high pressure oil pump delivers fuel from its outlet to the oil cooler, then to the oil filter. After leaving the filter, the flow splits into two paths: one path is pressure reduced for lubrication oil, and the other becomes control oil. One or two accumulators may also be installed in the oil circuit. Its core function is to increase fuel pressure, achieve high pressure injection, and attain the ideal atomization effect.
At the same time, the high pressure oil pump serves as the interface between the high pressure circuit and the low pressure circuit. It generates the required fuel pressure inside the common rail by controlling the fuel output volume. Under all operating conditions, the high pressure oil pump is primarily responsible for supplying sufficient high pressure fuel to the common rail, ensuring stable engine operation.
Working Principle of the high pressure oil pump:
SORTECH high pressure oil pump adopts a single plunger pump design integrating a pulsation damper, a flow control valve, and a pressure relief valve. Its working principle is that a cam drives the high pressure pump plunger to move up and down, achieving fuel intake and delivery. The ECU uses the pressure sensor on the fuel rail to perform closed loop control of the high pressure pump flow via the flow control valve according to the set control program, thereby precisely regulating the pressure inside the high pressure fuel rail. Among these components, the pulsation damper suppresses pressure pulsation on the low pressure side, improving system stability; the pressure relief valve opens when the pressure inside the high pressure fuel rail exceeds the safety limit, protecting the system.
Three Processes of Converting Low Pressure Fuel to High Pressuse Fuel in the High Pressure Oil Pump:
The high pressure oil pump converts low pressure fuel into high pressure fuel mainly through the following three processes:
1. Intake Stroke
During intake, the outlet valve is closed and the inlet valve opens. The pump piston moves downward as the camshaft cam rotates, reducing the pressure inside the pump chamber. Fuel is drawn from the low pressure fuel line into the pump chamber.
2. Compression Stroke
During compression, the outlet valve remains closed, and the ECU keeps the inlet valve closed as well, forming a sealed space in the pump chamber. The pump piston moves upward, reducing the pump chamber volume, compressing the fuel inside the chamber, and raising the fuel pressure.
3. Delivery Stroke
During delivery, the pump piston continues moving upward while the inlet valve remains closed. Since the fuel pressure inside the pump chamber is greater than the pressure in the high pressure fuel line, the outlet valve is pushed open, and the fuel in the pump chamber is pumped out and flows to the high pressure fuel line.
Through the above three steps, the high pressure oil pump draws low pressure fuel from the low pressure fuel line, converts it into high pressure fuel, and supplies it to the high pressure fuel line, providing reliable support for precise combustion in direct injection engines.
SORTECH deeply cultivates the fuel system field, offering high quality high pressure oil pump products and supporting services. With advanced single plunger pump design and precision control technology, SORTECH ensures stable fuel pressure and full atomization, helping engines improve power, reduce fuel consumption, and minimize carbon deposit formation.
Dedicated to guarding the energy of every drop of fuel. SORTECH keeps your engine running as powerfully as new.
