| 摘要 |
PURPOSE:To permit to secure a necessary delivery amount under low temperature by a method wherein a spring, made of shape memory alloy increasing the height of the spring under the low temperature, is provided to increase the force of the spring pressing a movable ring under the low temperature. CONSTITUTION:Under low temperature, the disc spring 32 of the shape memory alloy deforms so as to increase the height thereof and the initial set pressure of the spring 25 is increased, therefore, the force to press the movable ring 21 is also increased. Therefore, the displacement of the movable ring 21 is not caused until a high pressure difference is generated by the rotation of a rotor 23, however, under the low temperature, the viscosity of fluid is increased and the pressure difference between before and after an orifice becomes high in the same flow amount and the pressing force of the spring 25 is increased, thereby permitting to secure the necessary flow amount. |
