Seal assembly for a pressurized fuel feed system for an internal combustion engine

#The present invention relates to a seal assembly for use in a pressurized fuel feed system for an internal combustion engine, in particular for sealing the fluid flow passages of a throttle or carburetor or the like. The present invention thus provides a pressurized fuel feed system for an internal combustion engine, a throttle for use with an internal combustion engine operating on a pressurized fuel, and an internal combustion engine comprising such a pressurized fuel feed system and throttle.

#Systems for supplying fuel and fuel/air mixtures to internal combustion engines have long been known and are well developed. It is possible to characterize an internal combustion engine according to the manner in which the fuel is delivered to the inlet manifold of the engine. In many cases the engine is normally aspirated, that is using the low pressure or partial vacuum generated by the descending piston of the engine to draw fuel or a mixture of fuel and air into the cylinder. The amount of fuel fed to the engine and the flow of fuel/air mixture is typically regulated on such engines using a throttle or carburetor.

#As an alternative to the normally aspirated fuel supply system, fuel injection systems have been developed and are now commonly employed on internal combustion engines operating with normally liquid hydrocarbon fuels, such as gasoline and diesel. In a typical fuel injection system, the normally liquid fuel is injected under pressure into the cylinders of the engine at the appropriate time during the combustion cycle.

#Embodiments of the present invention will now be further described, by way of example only, having reference to the accompanying figures, in which:

#FIG. 1 is a perspective representation of a throttle assembly according to an embodiment of the present invention showing the inlet side of the throttle;

#FIG. 2 is a perspective representation of the throttle assembly of FIG. 1 along the line II-II;

#Referring to FIG. 1, a throttle assembly, for, by way of example, an internal combustion engine 1, is shown and generally indicated as 2. The throttle assembly shown is a commercially available integrated throttle body (ITP) as supplied by Woodward Governor Company. The commercially available throttle assembly employs gasket connections throughout. These connections have been modified to provide a sealing arrangement in accordance with the present invention, as described in detail below.

#The throttle assembly 2 of FIG. 1 comprises a throttle body 4 having a substantially cylindrical fuel passage 6 therethrough. An inlet flange 8 is formed on the throttle body 4 such as to surround the inlet opening of the fuel passage 6. The inlet flange 8 may be connected to a corresponding flange of an engine fuel supply system (not shown for clarity). The throttle body 4 is mounted to a throttle actuator 10 by means of flanges 12 and 14 formed on the throttle body 4 and throttle actuator 10 respectively and bolts 16. The throttle actuator 10 may be an suitable actuating means for operating the throttle, for example a servo. Such actuators are commercially available, for example the Woodward LCS actuator. Control signals are supplied to the actuator by means of a connector 18.

#The throttle body 4 is provided with an end plate 20, shown in more detail in FIG. 2 and described below. The end plate 20 locates and retains one end of a throttle shaft (not shown) extending across the fuel passage 6. The throttle shaft is operated by the actuator 10 and moves a throttle element 22 located in the fuel passage 6, thereby regulating the flow of gaseous fuel through the throttle assembly 2.