Fluid control valves
First Claim
1. A fuel injector comprising an injector body with a bore defined by a wall of said body, a fluid pressure actuated valve member slidably supported in the bore by said wall, a seating defined in the body, said valve member being shaped to co-operate with the seating to prevent flow of fluid through the injector, the valve member and seating being formed from electrically conductive material, resilient means acting to urge the valve member into contact with the seating, said valve member in use, being lifted from said seating against the action of the resilient means by fluid under pressure to permit flow of fluid through the injector, electrically insulated terminal means on said body, means within the body connecting said terminal means to the valve member, and a film of the fluid in the injector being the sole means for electrically insulating the valve member from the wall of the bore and from the body when said valve member is lifted from the seating, whereby the electrical resistance between the valve member and the body can be monitored whilst the injector is in use thereby to provide an indication of when the valve member is lifted from or moved into contact with the seating.
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Accused Products
Abstract
A fluid control valve, principally for controlling the flow of fuel to a compression ignition engine, comprises a valve body and a valve member slidable within the body, the valve member co-operating with a seating on the valve body to control the flow of fluid through the valve. A spring urges the valve member into engagement with the seating and in use, the pressure of the fluid entering the valve is arranged to act on the valve member in opposition to the spring so as to lift the valve member off the seating. The valve member and the seating are formed from electrically conductive material and are electrically insulated from each other except when the valve member is engaged with the seating. An electrical terminal extends to the exterior of the valve body and enables the electrical resistance between the valve member and the seating to be measured. The measured electrical resistance provides an indication of movement of the valve member towards and away from the seating.
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Citations
9 Claims
- 1. A fuel injector comprising an injector body with a bore defined by a wall of said body, a fluid pressure actuated valve member slidably supported in the bore by said wall, a seating defined in the body, said valve member being shaped to co-operate with the seating to prevent flow of fluid through the injector, the valve member and seating being formed from electrically conductive material, resilient means acting to urge the valve member into contact with the seating, said valve member in use, being lifted from said seating against the action of the resilient means by fluid under pressure to permit flow of fluid through the injector, electrically insulated terminal means on said body, means within the body connecting said terminal means to the valve member, and a film of the fluid in the injector being the sole means for electrically insulating the valve member from the wall of the bore and from the body when said valve member is lifted from the seating, whereby the electrical resistance between the valve member and the body can be monitored whilst the injector is in use thereby to provide an indication of when the valve member is lifted from or moved into contact with the seating.
Specification