Patent attributes
An injector has an inner sleeve between a needle pressure receiving face of a needle and a rear end face of a valve body. The inner sleeve is slidably fitted to an outer periphery of a middle shaft section of the needle. The inner sleeve receives a reaction force of a spring located between the inner sleeve and a pressurizing piston, so an axial tip end (edge section) of the inner sleeve is pressed against the rear end face to achieve close contact therebetween. Thus, a volume of a pressure chamber can be reduced, so a valve opening force for lifting the needle can be acquired efficiently. Accordingly, injection of a large flow rate can be performed by increasing a lift amount of the needle and also quick lifting of the needle can be performed.