Fuel Injection Device For Internal Combustion Engines

What is this patent about?

'824 is related to the field of fuel injection systems for internal combustion engines. Traditional fuel injection systems often struggle to precisely control the timing and volume of fuel injected, especially across varying engine speeds and loads. Prior art systems often require complex mechanical linkages or high-pressure intermediate reservoirs, adding to the cost and complexity of the system.

The underlying idea behind '824 is to achieve precise control over fuel injection by using two electrically controlled valves in sequence. The first valve controls the start of injection by allowing fuel to flow from a high-pressure reservoir to the injector. The second valve controls the end of injection by relieving the pressure in the fuel line, effectively terminating the injection event.

The claims of '824 focus on a fuel injection device comprising a high-pressure reservoir, a first electrically controlled valve in a fuel line connecting the reservoir to a distributor aperture, and a second electrically controlled valve in a relief line connected to the distributor aperture. The injection start is determined by opening the first valve while the second is closed, and the injection termination is determined by opening the second valve.

In practice, a high-pressure pump maintains a constant fuel pressure in the reservoir. When the engine control unit (ECU) determines that fuel injection is needed, it opens the first solenoid valve, allowing high-pressure fuel to flow to the injector via a distributor groove. The duration of the injection is precisely controlled by the ECU, which opens the second solenoid valve to relieve the pressure and stop the fuel flow. This sequential control allows for very fine-grained adjustments to both the timing and quantity of fuel injected.

This design differs from prior approaches by eliminating the need for a high-pressure intermediate reservoir and simplifying the control mechanism. By using two electrically controlled valves in a coordinated manner, the system achieves precise injection control with fewer components and reduced complexity. This leads to a more universally controllable fuel injection device that is simpler to manufacture and maintain, while also improving fuel efficiency and reducing emissions.