Patent attributes
An engine system having a coolant control valve unit includes: first and second valve members each having a rod protruding through a center part of the first and second valve members, respectively; a third valve member having a piston rod disposed through a center part of the third valve member; a temperature-sensitive driver attached to one side surface of the third valve member; a cam member contacted with an end part of the first and second rods and of the piston rod; and a cam member driver to rotate the cam member and control an opening of first, second, and third coolant passages by the first, second and third valve members, respectively. In particular, the other end part of the piston rod is inserted into the temperature-sensitive driver to push or pull the piston rod depending on a sensed temperature of the coolant.