Valve timing adjustment device

A valve timing adjustment device that adjusts a valve timing of a valve of an internal combustion engine, the valve timing adjustment device comprising:

• a phase conversion unit that includes a hydraulic chamber and is capable of converting a rotational phase between a drive shaft and a driven shaft of the internal combustion engine by a hydraulic oil supplied from a hydraulic oil supply source to the hydraulic chamber, and adjusting a valve timing of the valve;
• a hydraulic oil control unit capable of controlling flow of the hydraulic oil supplied to the hydraulic chamber by controlling the hydraulic oil flowing through an oil supply passage connecting the hydraulic oil supply source and the hydraulic chamber;
• an oil passage portion that forms a first part of the oil supply passage inside;
• a recess hole connected to a radially outer side of the oil passage portion to form a second part of the oil supply passage inside;
• and
• a check valve part disposed in the oil supply passage to allow the hydraulic oil to flow from the hydraulic oil supply source to the hydraulic chamber, and restrict the hydraulic oil from flowing from the hydraulic chamber to the hydraulic oil supply source, wherein
• the check valve part includes
• a valve seat portion provided in the oil passage portion to form a valve seat,
• a sleeve having one end connected to the valve seat,
• a lateral hole formed to connect an inner peripheral wall and an outer peripheral wall of the sleeve so as to make an internal space of the sleeve to communicate with outside of the sleeve, and
• a valve body provided inside the sleeve so as to be separated from the valve seat or in contact with the valve seat, and
• the lateral hole has an opening exposed to outside of the sleeve, and a range of the opening overlaps with a range of the recess hole in an axial direction of the sleeve,
• the hydraulic oil control unit has a control spool formed in a cylindrical shape to reciprocate in the axial direction so as to control the hydraulic oil, and
• the check valve part is located radially inward or radially outward of the control spool.