Patent attributes
A cylindrically shaped valve rod is housed in a valve hole formed in a cylinder body in a manner so as to be rotatable around a center axis line, and a connecting hole having a first hole opening that is allowed to communicate with a first flow path hole, and a second hole opening that is allowed to communicate with a second flow path hole is formed in the valve rod. A flow adjusting groove that is extending in a circumferential direction around an outer periphery of the valve rod from a position of the first hole opening is formed, and the flow adjusting groove is formed such that a groove width gradually narrows toward a tip end side and the groove depth gradually shallows at the same time, so that the valve opening extent is adjusted along with rotating operation of the valve rod.