The present invention provides a blade-type tensioner system for a chain that
can easily improve spring properties. A blade-type tensioner includes a blade shoe
and a blade spring positioned on the back side of chain sliding surface of the
blade shoe so as to impart tension to a chain through the blade shoe. The blade
shoe is pivotably supported around a shoulder bolt inserted into a proximal end
portion of the blade shoe, and a distal end portion of the blade shoe is slidably
supported on a supporting face provided in the engine. The distal end portion of
the blade shoe contacts a flat, first supporting face at a point. When tension
in the chain is increased, the distal end portion contacts a concave, second supporting
face at a point which is continuous with the first supporting face.