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US 4,905,645 AGranted
Safety system for internal combustion engines
AssigneeRobert Bosch GmbH
InventorsBernhard Bonse, Werner Fischer, Gerhard Stumpp
Life of this patent
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AssigneeRobert Bosch GmbH
InventorsBernhard Bonse, Werner Fischer, Gerhard Stumpp
Estimating the term…
To monitor the functioning of a redundant safety fuel shut off valve in a diesel engine, the electric power supply for a controlling device for the fuel quantity adjustor of a fuel injection pipe is decoupled from the power supply for the control of the electromagnetic fuel shut off valve. A relay controlled by a driving switch of the engine has a contact whose opening is time delayed relative to the opening of the driving switch. The relay contact is connected for energizing the controlling device for the fuel quantity adjustor whereas the energization and deenergization of the fuel shut off valve is effected immediately via a decoupling member. When the driving switch is opened and the engine is running during the given time delay interval, an error signal is generated indicating a malfunction of the fuel shut off valve.
A method of monitoring the function of a redundant safety member in the form of an electromagnetic fuel shut off valve (ELAB) in international combustion engines, particularly in Diesel engines having an electric power source, a fuel quantity adjustor acted upon by a Diesel regulator, an electronic controlling device (SG) for controlling the Diesel regulator and the ELAB whereby in the event of a failure the safety member is controlled to interrupt fuel supply to the engine, and switching means for controlling the electric power supply to switch on or off the engine, comprising the steps of delaying for a given time interval the deenergization of said SG and said Diesel regulator with each disconnection of said ELAB from the power source when the switching means is switched off;
A device for monitoring the function of a redundant safety member in the form of an electromagnetic fuel shut off valve (ELAB) in international combustion engines, particularly in Diesel engines having an electric power source, a fuel quantity adjustor acted upon by a Diesel regulator, an electronic controlling device (SG) for controlling the Diesel regulator and the ELAB whereby in the event of a failure the safety member is controlled to interrupt fuel supply to the engine, and switching means for controlling the electric power supply to switch on or off the engine, comprising means for decoupling the energization of said ELAB from said SG, Diesel regulator and fuel quantity adjustor, said switching means including a drive switch for energizing and deenergizing said ELAB, and a time delayed switch for deenergizing said SG, Diesel regulator and fuel quantity adjustor after a given time interval when the drive switch deenergizes via said decoupling means said ELAB.
Dependencies are inferred from the claim text.