US 5,295,469 A · Safety valve for fuel injection apparatus

Abstract

A safety valve provided in a fuel injection apparatus includes an accumulator in which fuel is accumulated. The housing has an inside passage for introducing high-pressure fuel of the accumulator into the inside of the housing and a seat face formed at a portion of the inside passage. A valve element provided movably within the housing includes a valve body to open/close the seat face and an elastic member for pressing and biasing the valve element in a closing direction. A fuel chamber defined between the inner surface of the housing and the valve element maintains pressure for pressing the valve element in a valve-opening direction, and high pressure fuel from the inside passage is introduced into the fuel chamber when the valve body of the valve element is separated from the seat face. With this safety valve, the high-pressure fuel of the accumulator is introduced into the fuel chamber in order to press the valve element in the valve-opening direction so that the valve element will be rapidly opened, with the result that the fuel pressure in the accumulator can recover a predetermined value instantaneously.

Claims14

Dependent claims

A safety valve for a fuel injection apparatus, said safety valve being provided in an accumulator in which pressurized fuel is accumulated and the pressurized fuel in said accumulator flows to a low-pressure side thereof, said safety valve comprising:

first valve means opened and closed by receiving the pressurized fuel pressure in said accumulator and for flowing out the fuel in said accumulator by opening said valve means when the fuel pressure in said accumulator reaches a pressure more than a predetermined pressure of the fuel in said accumulator, and
second valve means having a valve body moved from a first position by pressure of the fuel from said first valve means, said second valve means discharging the fuel from said first valve means to said low-pressure side by opening said second valve means when said valve body has moved a distance from said first position more than a predetermined stroke thereof.

A safety valve for a fuel injection apparatus, said safety valve being provided in an accumulator in which pressurized fuel is accumulated and flowing out the pressurized fuel of said accumulator to a low-pressure side thereof, said safety valve comprising:

a housing having a fuel passage for introducing the fuel of said accumulator thereinto and a seat surface formed in said fuel passage,
a movable valve member contained movably in said housing and for closing said fuel passage by abutting with said seat surface in a first position thereof and for closing said fuel passage by receiving the fuel pressure of said accumulator to move from said first position thereof so as to depart from said seat surface,
a biasing means for biasing said movable valve member toward said first position thereof,
a fuel chamber formed between said movable valve member and said housing and for flowing the fuel from said accumulator thereinto when said fuel passage is opened,
a passage formed between said movable valve member and said housing and for communicating said fuel chamber with said lower side thereof when the fuel is flown into said fuel chamber and said movable valve member is moved at a distance more than a predetermined stroke thereof from said predetermined position, and
a seal portion formed between said movable valve member and said housing and for restricting flowing out of the fuel from said fuel chamber to said lower side thereof during moving of said movable valve member at said predetermined stroke thereof.

3 more elements

Dependencies are inferred from the claim text.

Safety valve for fuel injection apparatus

Life of this patent

Safety valve for fuel injection apparatus

Life of this patent

Abstract

Claims14