Expansion valve

Abstract

An improved expansion valve is provided, which has a simple configuration and with which noise can be reduced. An expansion valve includes a valve main body having a valve chamber and a valve seat, a valve body configured to prevent passage of a fluid by being seated on the valve seat and allow passage of the fluid by separating from the valve seat, a coil spring configured to urge the valve body toward the valve seat, and an actuation rod configured to press the valve body toward a direction separating from the valve seat against an urging force applied from the coil spring, wherein the valve chamber includes a cylindrical inner wall being connected to the valve seat, the valve body includes a contact portion configured to be seated on the valve seat and a body portion having a tubular shape facing the inner wall, and the body portion includes connecting surfaces that are slidably in contact with the inner wall and plane surfaces that have a gap provided between the inner wall.

1 . An expansion valve comprising:
 a valve main body comprising a valve chamber and a valve seat;   a valve body configured to limit passage of a fluid by being seated on the valve seat and allow passage of the fluid by separating from the valve seat;   a coil spring configured to urge the valve body toward the valve seat; and   an actuation rod configured to press the valve body toward a direction separating from the valve seat against an urging force applied from the coil spring,   wherein the valve chamber comprises a cylindrical inner wall being connected to the valve seat,   the valve body comprises a contact portion configured to be seated on the valve seat and a body portion having a tubular shape facing the inner wall,   in a cross section taken in a direction orthogonal to an axis of the valve body, a shape of an inner circumference of the inner wall differs from a shape of an outer circumference of the body portion, so that a space through which the fluid passes is formed between the inner wall and the body portion, and the inner circumference of the inner wall and the outer circumference of the body portion are partially slidably in contact with each other,   bubbles in the fluid are collapsed when the fluid passes through the space formed between the inner wall and the body portion, and   the fluid passes the valve seat after passing through the space formed between the inner wall and the body portion.   
     
     
         2 . The expansion valve according to  claim 1 , wherein the inner wall comprises a cylindrical shape, and the body portion comprises a polygonal tubular shape. 
     
     
         3 . The expansion valve according to  claim 1 , wherein the inner wall comprises a polygonal tubular shape, and the body portion comprises a cylindrical shape. 
     
     
         4 . The expansion valve according to  claim 1 , wherein the inner wall comprises a cylindrical shape, and the body portion comprises a non-round cross section. 
     
     
         5 . The expansion valve according  claim 1 , wherein the actuation rod and the valve body are abutted against each other in a relative displaceable manner.