Sealing system for multiple fluids

A seal (301) has a first surface capable of contacting a valve cover (101) over a first fluid while a second surface, opposed to the first surface, is capable of contacting a seal seat (303). The seal (301) also has a third surface capable of contacting a sensor (201) disposed in a second fluid, while a fourth surface, opposed to the third surface, is capable of contacting the seal seat (303). The seal (301) is capable of separating the first fluid from the second fluid while preventing the first fluid and the second fluid from leaking out of the valve cover (101).

FIELD OF THE INVENTION

This invention relates to internal combustion engines, including but not limited to methods and apparatus utilized in assembling internal combustion engines.

BACKGROUND OF THE INVENTION

Injection control pressure (ICP) sensors are known in the art. These devices are typically used to measure oil pressure or fuel pressure in order to obtain the fuel injection pressure and to transfer the information to an engine control module or other electronic device for use in controlling fuel injection for an internal combustion engine. ICP sensors may need to be serviced or maintained at times. Thus, it is desirable to locate the ICP sensor in an advantageous place to both measure fuel pressure and to service the ICP sensor.

Accordingly, there is a need for a way to mount an ICP sensor in an internal combustion engine that provides adequate fuel injection pressure readings while maintaining serviceability for the ICP sensor.

SUMMARY OF THE INVENTION

A seal comprises a first surface capable of contacting a valve cover over a first fluid while a second surface, opposed to the first surface, is capable of contacting a seal seat. The seal also comprises a third surface capable of contacting a sensor housing disposed in a second fluid, while a fourth surface, opposed to the third surface, is capable of contacting the seal seat. The seal is capable of separating the first fluid from the second fluid while preventing the first fluid and the second fluid from leaking out of the valve cover.

DESCRIPTION OF A PREFERRED EMBODIMENT

The following provides a method and apparatus for mounting an ICP sensor on the fluid rail under the valve cover such the ICP sensor connects through the valve cover to allow electrical connections to be made above the valve cover while maintaining a location for the sensor within the fluid rail under the valve cover. A unique seal having a plurality of ridges and valleys on both sides of the seal is disposed between the valve cover, the ICP sensor, and the fluid rail such that fluids and/or contaminants do not leak under the valve cover or out of the valve cover, while maintaining the ability to easily remove or replace the ICP sensor. The present invention provides the ability to remove the valve cover without having to remove the ICP sensor as well as to remove the ICP sensor without having to remove the valve cover.

A top view of a valve cover101is shown inFIG. 1with a circular support member103extending away from the surface of the valve cover101and outside an opening105through which a fluid rail107is partially visible. The fluid rail may contain, for example, oil, fuel, or another fluid that is utilized to control fuel injector pressure. As shown inFIG. 2, one part of an ICP sensor201is inserted into the fluid rail107while another part of the ICP sensor201extends above the valve cover101. Electrical connections to the ICP sensor201are located outside the valve cover101of the internal combustion engine for easy connection to an engine control module or other device to receive the fuel pressure readings from the sensor201. The ICP sensor201is shown inFIG. 3operably connected to the fluid rail107, but with the valve cover101removed. A seal301is disposed between the ICP sensor201and a seal seat303. A close-up view of the valve cover101showing support member103and the mounted ICP sensor201with the seal301is shown inFIG. 4.

A partial cross-sectional view of the ICP sensor201mounted through the valve cover101and in the fluid rail107is shown inFIG. 5. A ninety-degree cutaway of the ICP sensor201, the fluid rail107, and the valve cover101is illustrated. The seal301is disposed between the ICP sensor201and a seal face501of the seal seat303of the fluid rail107. The seal301is also disposed between a compression flange503of the valve cover101and the seal face501. The support member103, which extends away from the valve cover101, is a strengthening element that provides support for the compression flange503such that the valve cover101, when tightened down, through the support member103, provides an additional pressure on the compression flange503. The compression flange503compresses the seal301to keep cylinder head fluids from engaging with the ICP sensor201and from leaking out through the valve cover101.

The ICP sensor201is shown in partial cutaway with a cross-section of the valve cover101, the seal301, and the seal seat303inFIG. 6. The ICP sensor201is mounted in the fluid rail107with the seal301and valve cover101installed. As shown, the seal301rests on the seal face501of the seal seat303of the fluid rail107. Part of the seal301is compressed between the ICP sensor201and the seal face501. Another part of the seal301is compressed between the compression flange503of the valve cover101and the seal face501.

The sealing seat303is comprised of the seal face501, which is advantageously a substantially flat surface having a central hole through which the ICP sensor201mounts into the fluid rail107. At the outer perimeter of the seal seat303is a lip601that extends above the seal face501. The lip601prevents the seal301from spreading radially outward after installation. An internal edge of the lip603is at least partially chamfered or angled radially outward to facilitate locating the seal301during installation. The chamfer603may be, for example, approximately twenty degrees from a perpendicular to the seal face501, and the chamfer603may be approximately one mm high. The chamfer may extend all the way from the seal face501to the outer perimeter or upper edge of the lip601or may begin part of the way up the lip601and extend to the outer perimeter or upper edge of the lip601. If the outer diameter of the seal301moves away from the seal face501as the ICP sensor201is installed, the chamfer603allows the seal301to be reseated. When the valve cover101is installed, the chamfer603facilitates reseating of the seal301on the seal face501.

A top view of the seal301is shown inFIG. 7, a bottom view of the seal301is shown inFIG. 8, and a cross-sectional view of the seal301is shown inFIG. 9. Although the terms “top” and “bottom” are utilized herein with respect to the seal301, such terms are utilized for reference only and do not definitively define orientation of the seal301. The seal301may be utilized in any orientation, at any angle, including horizontally, vertically, as well as reversed, upside down, and so forth. The top surface of the seal301is comprised of a seal bead701, two relatively flat surfaces703and707below the seal bead701, and a notch705below the flat surfaces703and707. The bottom surface of the seal301is comprised of three relatively flat surfaces801,805, and809. The outer flat surface801curves toward the outer perimeter901of the seal301. Two notches803and807are present on the bottom surface of the seal301. The seal301is advantageously circular in shape, and the seal bead701, surfaces703,707,801,805, and809, and notches705,803, and807are all advantageously concentrically circular in nature.

Once the seal301is installed as shown inFIG. 6, the seal bead701of the seal engages the compression flange503of the valve cover101while the sealing face501engages surfaces801and805of the seal301to prevent fluids from under the valve cover101(e.g., in the cylinder head) from leaking into the fluid rail107and/or engaging with the ICP sensor201and from leaking out of the valve cover101. The surfaces703and707engage the housing of the ICP sensor201while the sealing face501engages the surface809of the seal301to prevent fuel from the fluid rail107from leaking under the valve cover101and from leaking out of the valve cover101. Similarly, the seal301prevents fluids and/or contaminants from outside the valve cover101, such as oil, dirt, grease, and other solid and/or liquid materials, from entering the housing of the ICP sensor201and from getting under the valve cover201.

Although the sealing system is described herein with respect to an ICP sensor mounted to a fluid rail and through a valve cover, the system may be utilized in other situations as well.

The present invention provides numerous advantages. The sealing system and apparatus provide a robust manner of sealing an ICP sensor to a fluid rail while preventing fluids from escaping out of the valve cover and between the rail and the cylinder head. Because the ICP sensor obtains better measurements closer to the fuel injectors, it is advantageous to place one or more ICP sensors on one or more fluid rails, and the sealing system facilitates this advantage. The sealing system set forth herein facilitates installed the ICP sensor on the rail before or after the valve cover is placed on the engine, and also provides for easy serviceability and maintenance of the ICP sensor. Adequate sealing is provided throughout. The valve cover may be removed or serviced without having to remove the ICP sensor, and the ICP sensor may be removed or serviced without having to remove the valve cover.