Abstract: An anti-coking bushing assembly for sealing a pintle shaft of an EGR control valve, comprising a bushing carrier disposed in the valve body and supportive of close-fitting pintle shaft bushing liners formed of a polyimide such as Vespel. The bushing carrier and bushing liners are installed into a carbon shield extending into the exhaust flow space within the valve. Within the carbon shield, between the gas flow space and the bushing carrier, is a ring seal on the pintle shaft and a gas expansion chamber to cool exhaust gas escaping along the pintle shaft, allowing contaminants in the exhaust gas to precipitate in the gas expansion chamber. The carbon shield, ring seal, bushing carrier, and bushing liners are conveniently pre-assembled as an anti-coking bushing assembly for subsequent installation into a valve body during final valve assembly.

Abstract: An anti-coking bushing assembly for sealing a pintle shaft of an EGR control valve, comprising a bushing carrier disposed in the valve body and supportive of close-fitting pintle shaft bushing liners formed of a polyimide such as Vespel. The bushing carrier and bushing liners are installed into a carbon shield extending into the exhaust flow space within the valve. Within the carbon shield, between the gas flow space and the bushing carrier, is a ring seal on the pintle shaft and a gas expansion chamber to cool exhaust gas escaping along the pintle shaft, allowing contaminants in the exhaust gas to precipitate in the gas expansion chamber. The carbon shield, ring seal, bushing carrier, and bushing liners are conveniently pre-assembled as an anti-coking bushing assembly for subsequent installation into a valve body during final valve assembly.

Abstract: A fuel injection apparatus for use in an internal combustion engine includes a fuel injector having a valve member which is operable to control injection of fuel through an injector outlet, a first supply path having a first path length for delivering fuel to an injector control chamber, a second supply path having a second path length for delivering fuel to an injector delivery chamber and a control valve for controlling fuel pressure within the injector control chamber so as to control movement of the valve member. An actuation means is arranged to vary at least one of the first and second path lengths in response to one or more injection parameters. Varying the first and/or second path length enables resonant pressure pulses within the control chamber and/or delivery chamber to be optimised so as to minimise the pressure differential across the valve needle at the instant of closure of the control valve to terminate injection, thus reducing needle closure response.

Abstract: An object of the present invention is to obtain a consistently stable needle lift damping effect in an injector 8b for fuel injection. In an injector 8b that relieves fuel pressure inside a pressure control chamber 37 and lifts a needle valve 36, there are provided a damper member 62 that is slidably mounted to the needle valve 36, a damping chamber 63 formed between the damper member 62 and the needle valve 36, a leak passage 64 for extracting and leaking out the fuel in the damping chamber 63, and a stopper member 41 to restrict the lift position of the damper member 62. Damping of the lift of the needle valve 36 is carried out by extracting and leaking out the fuel in the damping chamber 63 through the leak passage 64. The needle valve 36 functions as a guide for the damper member 62, and prevents vibration of the damper member 62, allowing a consistently stable damping effect to be obtained.