The present invention addresses the problem of providing a sintered alloy valve guide capable of inhibiting valve adhesion even in a high-temperature environment. The problem can be solved by a sintered alloy valve guide impregnated with a lubricating oil including pores that are sealed on the valve guide outer circumferential surface. More particularly, the problem is solved by the sealing step of performing a sealing treatment of pores on the outer circumferential surface of a sintered body impregnated with a lubricating oil.

A valve spring retainer for an internal combustion engine includes a body having a lower portion and an upper portion. The lower portion defines a radial flange and a first opening extending axially therethrough. The upper portion includes a first wall and a re-entrant lip. The first wall extends at least partially axially away from an outer perimeter edge of the radial flange. Together, the first wall and the radial flange define an open reservoir for receiving and retaining oil therein. The re-entrant lip extends from an outer end of the first wall at least partially radially inward toward a central axis of the first opening. The re-entrant lip extends over a portion of the reservoir defined by the first wall and the radial flange.

A valve spring retainer for an internal combustion engine includes a body having a lower portion and an upper portion. The lower portion defines a radial flange and a first opening extending axially therethrough. The upper portion includes a first wall and a re-entrant lip. The first wall extends at least partially axially away from an outer perimeter edge of the radial flange. Together, the first wall and the radial flange define an open reservoir for receiving and retaining oil therein. The re-entrant lip extends from an outer end of the first wall at least partially radially inward toward a central axis of the first opening. The re-entrant lip extends over a portion of the reservoir defined by the first wall and the radial flange.

Arrangement comprising: a chamber that is formed between a first receptacle and a second receptacle for a rod-shaped element, wherein the receptacles open out to the chamber on opposite end-face sides thereof; a rod-shaped element that is accommodated in the receptacles via a respective section with radial play, in this regard with a receptacle radial play, the rod-shaped element passing through the chamber; and an annular body that is situated in the chamber and through which the rod-shaped element passes with radial play, in this regard an annular body radial play, wherein the annular body radial play is less than the receptacle radial play, wherein the arrangement has a first media side and a second media side that are connected to the chamber via the first receptacle and second receptacle, respectively, wherein the annular body is provided to be pressed into contact against an end-face side of the chamber.

The present invention addresses the problem of providing a sintered alloy valve guide capable of inhibiting valve adhesion even in a high-temperature environment. The problem can be solved by a sintered alloy valve guide impregnated with a lubricating oil including pores that are sealed on the valve guide outer circumferential surface. More particularly, the problem is solved by the sealing step of performing a sealing treatment of pores on the outer circumferential surface of a sintered body impregnated with a lubricating oil.

A valve arrangement is provided for supplying air to a combustion chamber of an internal combustion engine, the valve arrangement including a first valve, the first valve including a first valve head, a first valve stem and an internal cavity, which is partly located in the first valve stem and open towards a lower surface of the first valve head, a valve guide arranged to surround a portion of the first valve stem such that the first valve stem is movable in the valve guide along a longitudinal direction between an upper, closed position of the valve, and a lower, open position, in which open position air may be supplied to the combustion chamber past the first valve head, the valve guide including an air passage allowing supply of additional air to the combustion chamber via the internal cavity in the first valve, when the first valve is in its closed position. The valve arrangement includes a guide leakage preventing means for preventing liquid from leaking from a region externally of the first valve stem to the valve guide air passage.

A valve arrangement is provided for supplying air to a combustion chamber of an internal combustion engine, the valve arrangement including a first valve, the first valve including a first valve head, a first valve stem and an internal cavity, which is partly located in the first valve stem and open towards a lower surface of the first valve head, a valve guide arranged to surround a portion of the first valve stem such that the first valve stem is movable in the valve guide along a longitudinal direction between an upper, closed position of the valve, and a lower, open position, in which open position air may be supplied to the combustion chamber past the first valve head, the valve guide including an air passage allowing supply of additional air to the combustion chamber via the internal cavity in the first valve, when the first valve is in its closed position. The valve arrangement includes a guide leakage preventing means for preventing liquid from leaking from a region externally of the first valve stem to the valve guide air passage.

A device configured for controlling lubrication of rocker arms of an engine with a CDA function, may include valves, wherein the opening/closing state of valves is varied in accordance with an operation state of a vehicle, to which the device is applied, and then, amounts of oil supplied to respective rocker arms are adjusted. Accordingly, the oil pressure and oil pumping capacity of a main gallery may be reduced and then, an enhancement in fuel economy may be achieved. Furthermore, lubrication performance may be secured through an increase in oil supply amount.

A device configured for controlling lubrication of rocker arms of an engine with a CDA function, may include valves, wherein the opening/closing state of valves is varied in accordance with an operation state of a vehicle, to which the device is applied, and then, amounts of oil supplied to respective rocker arms are adjusted. Accordingly, the oil pressure and oil pumping capacity of a main gallery may be reduced and then, an enhancement in fuel economy may be achieved. Furthermore, lubrication performance may be secured through an increase in oil supply amount.

In a valve train of an internal combustion engine, an input sprocket mounting portion is provided on one end of an exhaust camshaft, and a valve operating cam portion is formed on the other end of the camshaft. A decompression shaft of a decompression device is inserted in a decompression shaft hole, which is formed from the input sprocket mounting portion toward the valve operating cam portion. The decompression shaft hole is formed at a position offset from an axis of the camshaft. A camshaft inner oil passage is formed in the camshaft to extend from one end toward the other end of the camshaft in parallel arrangement to the decompression shaft hole to supply lubricant from the bearing journal portion to the bearing journal portion. The above arrangement makes it possible to supply a sufficient amount of lubricant oil to slide portions of the valve train of a saddle riding vehicle.