Method of and device for safeguarding operation of an internal combustion engine
AssigneeRobert Bosch GmbH
InventorJurgen Brauninger
Life of this patent
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Abstract
A method of safeguarding operation of an internal combustion engine is based on the provision of two electrically controlled fuel supply pumps delivering fuel from a tank to a fuel metering device. During the start of the engine both fuel supplying pumps are activated. During a normal engine operation when rotary speed exceeds an iling value, a random fuel supplying pump is turned off. In a defect situation resulting from malfunction of the active pump both pumps are turned on to maintain fuel supply by the other pump. In an emergency situation when for example actual rotary speed exceeds a maximum value, both fuel supplying pumps are activated in reverse to suck fuel from the metering device and cause the standstill of the engine.
Claims12
A method of safeguarding operation of an internal combustion engine having a tank, a fuel metering device and an electrically controlled fuel pump for supplying fuel from said tank to said metering device, and means for injecting fuel into the engine in response to momentary operational conditions of the engine, comprising the steps of providing an additional electrically controlled fuel pump for supplying fuel from said tank to said metering device;
- activating both fuel supply pumps during starting operation when rotary speed of the engine has a low value n ;
- activating only one of said two fuel supply pumps during a normal engine operation when rotary speed n is greater than idling speed;
- and activating both fuel supply pumps into reverse run when an emergency operation occurs, whereby the two pumps suck fuel from said fuel metering device.
Dependencies are inferred from the claim text.