| CPC F01L 1/3442 (2013.01) [F01L 1/356 (2013.01); F16K 31/48 (2013.01); F16K 31/52483 (2013.01); F01L 2001/34426 (2013.01); F01L 2001/3443 (2013.01); F01L 2001/34433 (2013.01); F16K 11/0716 (2013.01); F16K 15/028 (2013.01); F16K 15/142 (2013.01)] | 13 Claims |
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1. A valve timing changing device for changing opening and closing timing of an intake valve or an exhaust valve driven by a camshaft, the valve timing changing device comprising:
a housing rotor that rotates coaxially with the camshaft;
a vane rotor that defines an advance chamber and a retard chamber together with the housing rotor and that rotates integrally with the camshaft; and
a fluid control valve that controls supply and discharge of hydraulic oil with respect to the advance chamber and the retard chamber,
wherein the fluid control valve comprises:
a sleeve in a bottomed cylindrical shape, comprising an inlet into which the hydraulic oil flows, a communication port that communicates with outside to allow the hydraulic oil to pass, a cylindrical inner peripheral surface centered on an axis, and an inflow annular groove that is recessed from the inner peripheral surface in a region facing the inlet;
a spool slidably disposed on the inner peripheral surface in the sleeve to open and close the communication port;
a C-shaped leaf spring which is formed by bending a leaf spring into an annular shape with two ends facing each other to form a notch with a predetermined gap and which is disposed in the inflow annular groove to be able to be contracted in diameter to open and close the inlet; and
a fitting pin provided on the sleeve for restricting diameter contraction of the C-shaped leaf spring beyond a predetermined inner diameter and for restricting a position of the notch in a region away from the inlet, wherein the fitting pin is fitted to a fitting hole of the sleeve,
wherein the inlet is a supply port to which the hydraulic oil is supplied,
wherein the communication port comprises a first communication port and a second communication port,
the first communication port is a retard port that communicates with the retard chamber, and
the second communication port is an advance port that communicates with the advance chamber,
wherein the C-shaped leaf spring is disposed such that the fitting pin is positioned in the gap of the notch, and is bent in advance to have an outer diameter larger than an inner diameter of the inflow annular groove formed in the sleeve,
in response to an action of the hydraulic oil on the C-shaped leaf spring, the C-shaped leaf spring relatively moves in a circumferential direction so that one end and the other end move toward the fitting pin, and contracts the outer diameter while maintaining the annular shape,
the diameter contraction of the C-shaped leaf spring stops in response to the one end and the other end coming into contact with each other to sandwich the fitting pin, and
the C-shaped leaf spring is restricted from contracting beyond the predetermined inner diameter by the fitting pin, the predetermined inner diameter is an inner diameter at which the hydraulic oil flowing from the supply port becomes a desired inlet amount and which secures a gap that allows the spool reciprocating inside the C-shaped leaf spring to move smoothly without contact so that the C-shaped leaf spring does not interfere with the spool while the outer diameter of the C-shaped leaf spring is contracted.
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