Pressure relief at fuel injection valve upon termination of injection
OwnerLloyd E. Johnsoninventor
Life of this patent
Estimating the term…
Abstract
Immediately downstream of the high pressure fuel pump and electrical signal is generated by that part of the fuel pressure impulse intended to cause the fuel injection valve to close. That electrical signal energizes a solenoid causing the opening of a pressure relief valve incorporated into the valve body of the fuel injection valve. The relief valve is timed to open upon the closing of the fuel injection valve. In a multi-cylinder engine, the pressure relief valves for all cylinders are opened simultaneously. The pressure relief valves discharge into a pressure relief chamber, which may be individual for each valve or a common manifold communicating with the fuel supply.
Claims19
In a fuel injection apparatus for an internal combustion engine having a combustion chamber, said apparatus including a fuel injection valve having a downstream side through which fuel is injected into said chamber and an upstream side, fuel pulse supply means connected to said upstream side for supplying metered and timed pulses of fuel to said valve for injection into said chamber, said pulses each having a start and an end, the improvement comprising:
- a normally closed relief valve having an intake opening communicating with the upstream side of the injection valve and a discharge opening;
- power means connected to the relief valve for opening the relief valve to permit communication between the intake and discharge openings in timed relationship to arrival at the injection valve of said ends of pulses of fuel flow;
- and
- means communicating with said discharge openings to receive fuel that may flow from the intake to the discharge openings when the relief valve is open.
In the method of injecting fuel into the combustion chamber of an internal combustion engine wherein a series of pressure impulses are produced in the fuel supply line in timed relationship, each impulse acting to open a check valve and permit a slug of fuel to be introduced into said chamber, the improvement comprising:
- sensing the existence of at least part of said impulse at a location upstream of said valve and producing a control signal thereupon;
- releasing into a low pressure area the fuel pressure immediately upstream of the check valve in response to said control signal.
Dependencies are inferred from the claim text.