ELECTROMAGNETIC LINEAR VALVE

摘要

In an electromagnetic linear valve, a resilient member urges a plunger in a direction in which the core-opposing portions move away from a core portion, and moves the plunger in a direction in which the core-opposing portions approach the core portion where an electric current is supplied to a coil. Where no electric current is supplied to the coil, an axially opposing surface area as a surface area of portions of the core-opposing portions which respectively oppose inner peripheral surfaces of recessed portions is smaller than a radially opposing surface area as a surface area of portions of the core-opposing portions which respectively oppose bottom surfaces of the recessed portions, and the axially opposing surface area becomes larger than the radially opposing surface area where an electric current is supplied to the coil and the core-opposing portions approach most to the core portion.

主权项

1. An electromagnetic linear valve comprising:
a housing including: (A) a partitioning member configured to partition the interior of the housing into a first liquid chamber and a second liquid chamber and being formed with a communicating hole communicating the first liquid chamber and the second liquid chamber with each other; (B) an inlet port communicating with the first liquid chamber and configured to allow working fluid to flow into the first liquid chamber; and (C) an outlet port communicating with the second liquid chamber to allow the working fluid to flow out from the second liquid chamber; a plunger disposed in the second liquid chamber and movable in the axial direction such that one end of the plunger is seated in an opening of the communicating hole; a resilient member configured to urge the plunger in one of a direction in which the one end approaches the opening of the communicating hole and a direction in which the one end is moved away from the opening; and a coil disposed around the housing and configured to generate a magnetic field for moving the plunger in a direction opposite to the direction in which the plunger is urged by the resilient member, wherein the housing includes a core portion formed of a ferromagnetic material and defining part of the second liquid chamber, the plunger includes a core-opposing portion opposing the core portion and allowing a magnetic flux to flow between the core portion and the core-opposing portion, the core portion includes a recessed portion which allows the core-opposing portion to face and enter therein, the core-opposing portion opposes a bottom surface of the recessed portion and opposes an inner peripheral surface of the recessed portion, the resilient member is configured to urge the plunger in a direction in which the core-opposing portion moves away from the core portion, and allow the plunger to move in a direction in which the core-opposing portion approaches the core portion against an urging force of the resilient member when an electric current is supplied to the coil, and the outer peripheral surface of the core-opposing portion has a portion opposing the inner peripheral surface of the recessed portion, and a radially extending portion of the core-opposing portion has a portion opposing a radially extending surface of the recessed portion, and an axially opposing surface area which is a surface area of the portion of the outer peripheral surface of the core-opposing portion is smaller than an radially opposing surface area which is a surface area of the portion of the radially extending portion of the core-opposing portion in the case where no electric current is supplied to the coil, and the axially opposing surface area becomes larger than the radially opposing surface area in the case where the electric current is supplied to the coil and the core-opposing portion approaches most to the core portion.