| 摘要 |
PURPOSE:To stabilize the fuel injection amount by shifting the operation body of a control valve apparatus which is constituted of an electrical strain element, according to the elongation and contarction of the electrical strain element and making the effective stroke of a piston which corresponds to the max. length of shift smaller than the whole stroke of the piston. CONSTITUTION:The fuel supplied by a feed pump 3 flows into a space 71 and fills also a space 11. An electrical strain element 5 elongates or contracts when a voltage is applied, and for example, when +500V is supplied, a piston 10 shifts downward by 50mum against the repulsive force of a spring 111. Since the upper edge surface of a needle body 22 is positioned above by the ring-shaped groove 19 of a cylinder 17 at this time, the pressure of the fuel in the space 11 increases to the hydraulic pressure over the repulsive force of a spring 24, and the needle body 22 is pushed downward. Though a clearance is provided between the slidable part 18 of the cylinder 7 and a piston part 221, fuel leak through the clearance is prevented, since transfer of the piston 10 is performed at high speed, and the needle body 22 is pushed downward, and the fuel in the space 71 is jetted-out. |
