| 摘要 |
A fuel injection valve includes a body (10) having a high pressure fuel passage (102) and a nozzle hole (103), which is connected to the passage, a nozzle needle (15) opening/closing the hole and having a needle piston part (152), a piezo stack (30) extended when the stack is charged and contracted when the stack discharges electric charge, a cylinder (20), in which the needle piston part is slidably inserted and which is driven by the stack, a fixed piston (40) having a fixed piston part (401) that is slidably inserted in the cylinder and that has a larger diameter than the needle piston part, an oil-tight chamber (45) between the needle piston part and the fixed piston part in the cylinder, and a nozzle spring (25) urging the needle in a valve closing direction. The cylinder is displaced due to extension/contraction of the stack, so that volume of the chamber increases/decreases and the needle opens/closes the hole. |
