Device for the timed injection of air into the exhaust ducts of an internal combustion engine

Claim 2

In an internal combustion engine having a cylinder head, at least a working cylinder in the head, a piston slidable in the working cylinder, an exhaust duct, an exhaust valve to vent exhaust gases from the cylinder to the exhaust duct, said exhaust valve having a head and a stem, the cylinder head having a bore, a valve guide in the bore to guide the stem of the exhaust valve, and a device for the timed injection of air into the exhaust duct, the device including at least a first duct, said first duct communicating with an air pressure source and having an outlet end, said outlet end being at the bore of the cylinder head in which the stem of the exhaust valve is slidably received, at least a second duct, said second duct being permanently connected with the exhaust duct and having an inlet end, said inlet end of the second duct being at the bore of the cylinder head for the stem of the exhaust valve, said first and second ducts being provided in the cylinder head and at least partially in the valve guide, said exhaust valve including a slide valve controlling the communication between the first and second ducts, the stem of the exhaust valve constituting the mobile member of the slide valve, the stem being provided with an annular groove, and the valve guide constituting the fixed member of the slide valve so that when the exhaust valve is opened, the first and second ducts are placed into communication through the annular grOove.

Claim 3

The device as claimed in claim 1 including a duct provided in the cylinder head and permanently connected to an air pressure source, and annular chamber coaxial with the exhaust valve and provided in the cylinder head near the valve guide, a plurality of radial bores in the valve guide, the bores communicating with the duct via the annular chamber, at least a substantially longitudinal groove in the inner surface of the valve guide terminating at the end of the valve guide, in the exhaust duct, the annular groove of the exhaust valve stem being of a width at least equal to the operative stroke of the exhaust valve, and the longitudinal groove being located not to interfere with the bores of the valve guide and the annular groove of the stem when the exhaust valve is closed.

Claim 4

The device as claimed in claim 2 in which a plurality of longitudinal grooves are provided in the valve guide, the longitudinal grooves being alternatingly positioned with respect to the radial bores of the valve guide so there is no interference there between, and the length of the longitudinal grooves being such as to avoid any communication with the annular groove of the valve stem when the exhaust valve is closed.

Claim 5

The device as claimed in claim 2 in which helical grooves are provided in the valve guide, the helical grooves having inlet and outlet ends, the outlet ends being at the exhaust duct and the inlet end being positioned so that there is no interference with the radial bores and the annular groove when the exhaust valve is closed.

Claim 6

In an internal combustion engine having a cylinder head, at least a working cylinder in the cylinder head, a piston slidable in the working cylinder, an exhaust duct, an exhaust valve to vent exhaust gases from the cylinder to the exhaust duct, the exhaust valve having a head and a stem, a valve guide to guide the stem of the exhaust valve, the cylinder head having a first duct connected to an air pressure source, and a device for the timed injection of air from the first duct into the exhaust duct, the device including a slide valve having fixed and movable components, the movable component being an annular groove provided about an intermediate portion of the stem of the exhaust valve, the annular groove having a length substantially equal to the opening stroke of the exhaust valve, the fixed component being defined by an annular chamber in the cylinder head about the valve guide, said annular chamber being in communication with the first duct, one or more radial bores in the valve guide to provide communication between the annular chamber and the interior of the valve guide, and one or more longitudinal grooves in the interior of the valve guide, each longitudinal groove having inlet and outlet ends, the longitudinal grooves being arranged so as not to interfere with the radial bores, the outlet ends of the longitudinal grooves communicating with the exhaust duct, and the outlet of the radial bores and the inlet ends of the longitudinal grooves being disposed in a crownlike arrangement about the valve stem and slightly below the annular groove of the valve stem when the outlet valve is closed whereby the valve stem arrests injection of air from the first duct but when the exhaust valve is in the open position, air is injected from the first duct via the annular chamber, the radial bores, the annular groove and the longitudinal grooves into the exhaust duct.

Claim 7

In an internal combustion engine having a cylinder head, at least a working cylinder in the cylinder head, a piston slidable in the working cylinder, an exhaust duct, an exhaust valve to vent exhaust gases from the cylinder to the exhaust duct, the exhaust valve having a head and a stem, a valve guide to guide the stem of the exhaust valve, the cylinder head having a first duct connected to an air pressure source, and a device for the timed injection of air from the first duct into the exhaust duct, the device including a slide valve having fixed and movable components, the movable component being an annular groove provided about an intermediate portion of the stem of the exhaust valve, the annular groove having a length substantially equal to the opening stroke of the exhaust valve, the fixed component being defined by an annular chamber in the cylinder head about the valve guide, said annular chamber being in communication with the first duct, one or more radial bores in the valve guide to provide communication between the annular chamber and the interior of the valve guide, and one or more longitudinal grooves in the interior of the valve guide, each longitudinal groove having inlet and outlet ends, the longitudinal grooves being arranged so as not to interfere with the radial bores, the outlet ends of the longitudinal grooves communicating with the exhaust duct, and the outlet of the radial bores and the inlet ends of the longitudinal grooves being disposed in a crownlike arrangement about the valve stem and slightly below the annular groove of the valve stem when the outlet valve is closed whereby the valve stem arrests injection of air from the first duct but when the exhaust valve is in the open position, air is injected from the first duct via the annular chamber, the radial bores, the annular groove and the longitudinal grooves into the exhaust duct.