US Patent 10280829 Flow rate control valve

Flow rate control valve CV has first housing 11 having introduction opening 10 opening in axial direction of hollow valve body accommodating portion 13 and introducing cooling water and first to third exhaust ports E1-E3, each of which is formed so as to have opening cross section that is smaller than that of introduction opening 10, radially communicates with valve body accommodating portion 13 and exhausts cooling water in valve body accommodating portion 13; and valve body 3 rotatably supported in valve body accommodating portion 13 and having opening portions M1-M3 whose overlap state with exhaust ports E1-E3 is changed according to rotation position of valve body 3. Opening cross section between introduction opening 10 and third opening portion M3 (exhaust port E3) is reduced in axial direction of valve body accommodating portion 13, thereby suppressing rapid reduction of flow passage sectional area and decreasing flow resistance of cooling water.