Hydraulic oil control valve and valve timing adjustment device

A hydraulic oil control valve configured to control a hydraulic oil pressure of hydraulic oil to be supplied to a valve timing adjustment device that is configured to adjust an opening timing and a closing timing of a valve of an internal combustion engine, the hydraulic oil control valve comprising:

• a sleeve that is shaped in a cylindrical tubular form, wherein an opening is formed at one end portion of the sleeve, and a spring seat is formed at another end portion of the sleeve;
• a spool that is configured to move forward and backward in an inside of the sleeve, wherein the spool is configured to adjust a supply destination of the hydraulic oil according to a positional relationship between the spool and the sleeve;
• an actuator that contacts the spool and is configured to drive the spool toward the spring seat;
• and
• a spring that is configured to be seated against the spring seat of the sleeve and is configured to apply a preload to the spool toward the actuator, wherein the spring has a first end portion, which has an outer diameter and an inner diameter that are set to enable the first end portion to seat against the spring seat, and a second end portion, which is spaced from the first end portion by a free length of the spring, wherein:
• the sleeve has:
• a stepped portion, which surrounds the spring seat on a radially outer side of the spring seat and has a spool contact surface that is configured to limit movement of the spool toward the spring seat;
• and
• a protrusion, which is located at a center of the spring seat and protrudes toward the opening, wherein a maximum diameter of the protrusion is smaller than the inner diameter of the first end portion of the spring, and the protrusion has a sloped peripheral surface that has an outer diameter which is progressively reduced from one side of the sloped peripheral surface, at which the spring seat is placed, toward the opening;
• and
• the protrusion is configured such that in a state where the first end portion is not seated against the spring seat of the sleeve while the spring is placed adjacent to the spring seat, the first end portion is placed in contact with the protrusion.