| 摘要 |
PURPOSE:To allow a fixed quantity to flow when the opening is fixed regardless of a change in the coefficient of viscosity of a fluid based on a change of the liquid temperature by providing a large-diameter step section at the portion where a needle is protruded into a fluid chamber. CONSTITUTION:When the fluid pressure in a fluid chamber is increased, the fluid pressure is applied to a large-diameter step section 29a as a pressing force to move a needle 29 to the left side against the tensile force of a spring 37 and expand the opening portion of a fluid discharge port 28. FC is an attractive force applied to the needle 28 in the left direction by a solenoid, FS is a pressing force in the right direction applied by the spring 37, and FP is a pressing force in the left direction applied to the large- diameter step section 29a of the needle 29 by the fluid pressure. PL is the input pressure of the fluid, PO is its output pressure, and S is the pressure receiving area of the large-diameter step section 29a. The fluid pressure FP applied to the large-diameter step section 29a is FP POXS, and since the output pressure PO from the fluid chamber can be determined as a function of a force A.I generated by the pressing force FS of the spring 37 and the solenoid and the pressure receiving area S of the large-diameter step section 29a, it can be maintained nearly constant without being affected by the coefficient of viscosity of the fluid. |
