Control valve

A control valve comprising:

• a casing including an inlet through which a liquid flows in from an outside and an outlet through which the liquid that has flowed in an inside flows to the outside;
• a valve body which is rotatably disposed inside the casing and includes a circumferential wall portion formed with a valve hole providing communication between the inside and the outside;
• and
• a seal cylinder member of which one axial end portion communicates with a downstream side of the outlet and an other axial end portion is provided with a valve sliding contact surface that slidably comes into contact with an outer circumferential surface of the circumferential wall portion at a position at least partially overlapping a rotational path of the valve hole of the valve body,
• wherein a flow rate control groove including a bottom surface which is recessed with respect to the outer circumferential surface of the circumferential wall portion and includes one end portion that is continuous with the valve hole is provided on at least one of a front side and a rear side of an edge portion of the valve hole in the circumferential wall portion in a rotating direction of the valve body,
• wherein the bottom surface has a linear first end side parallel to an axis of the valve body, and
• wherein the first end side is a boundary portion with the outer circumferential surface of the circumferential wall portion.