Patent Application
20090250643
The present invention relates generally to vehicle check valves.
Electromechanical actuators are used in many vehicle applications to control fluid flow in vehicle systems such as anti-lock brake systems (ABS) and fuel injection systems. Using the latter application as an example, the pressure pulsations from a fuel pump that is driven by a belt or directly from an engine shaft can be controlled by one or more solenoid-operated check valves, the operation of which can be synchronized with a camshaft to deliver the required flow and pressure to fuel rail injectors.
In such an application, the valve plainly must operate very quickly. A variety of factors can complicate achieving proper valve operation under such trying conditions. Among these factors are friction, hydraulic stiction, misalignment, improper damping, inertia, and mass, to name a few. As understood herein, at least some of these factors can be alleviated by reducing the hydraulic forces on the valve. Moreover, as also understood herein reducing hydraulic forces can enhance the ability of the valve to operate very quickly. Still further, the present invention recognizes that reducing hydraulic forces in many applications can have a beneficial cascading effect, e.g., a less-massive valve which has less inertia to resist quick response can be provided.
A check valve has a valve housing slidably supporting an actuator rod. A hollow valve seat insert is disposed in the housing. The insert can be hardened but the housing need not be hardened. The insert defines a rod guide slidably receiving the rod and a lobe-shaped opening defining a valve seat. A valve element is juxtaposed with the valve seat for selectively blocking the opening.
The valve element can be formed with at least three lobes, as can be the opening. The lobes can be contiguous to each other.
The rod may be moved by actuating a coil. In such an embodiment, the rod can be urged against the valve element by a spring to distance the valve element from the valve seat when the coil is deenergized. The coil when energized moves the rod away from the valve element to allow fluid pressure to urge the valve element against the valve seat.
In another aspect, a valve includes a valve housing slidably supporting an actuator rod, and a hollow lobe-shaped valve seat is in the housing. A valve element is juxtaposed with the valve seat for selectively blocking an opening circumscribed by the valve seat.
In still another aspect, an actuator includes a valve housing slidably supporting an actuator rod. A valve seat is in the housing and circumscribes a non-round opening. Also, a valve element is juxtaposed with the valve seat and a spring urges the rod toward the valve element in an open configuration. A coil is energizable to move the rod away from the valve element in a closed configuration.
The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:
Referring initially to
Accordingly and as perhaps best shown in
In accordance with present principles, a hollow rigid valve seat insert 40 is made separately from the housing 18 and is disposable in the axial channel 32 of the valving component enclosure 22. The insert 40, which can be press fit into the housing 18, preferably is metal that can be hardened using, e.g., precipitation/age hardening to improve its wear characteristics, while the housing 18, being relieved of some of its wear requirements by the insert 40, need not be hardened so as to optimize its magnetic characteristics.
As shown, the example insert 40 defines an axially-oriented hollow rod guide 42 that slidably receives the rod 30. The walls of the rod guide 42 may be continuous or, as shown, may be defined by plural (e.g., three) axially-oriented wall portions, the inside surface of each of which defines a portion of a cylinder.
At a lower end of the rod guide 42, the insert 40 defines a disk-shaped seat member 44, the upper surface of which abuts the shoulder 38 of the valving component enclosure 22 of the housing 18. A continuous axial passageway is formed by the rod guide 42, and the passageway terminates in an opening 46 of the seat member 44. In accordance with present principles, the opening 46 is not round; in the specific example shown in
A valve element 50 that may be made of resilient plastic rubber is juxtaposed with the valve seat 48 for selectively blocking the opening 46 as shown. The valve element 50 may be generally disk-shaped, and in one non-limiting embodiment the valve element 50 may have plural (e.g., three) small protrusions 52 that may be thought of as “lobes” that are not contiguous to each other, i.e., the lobe-like protrusions 52 are separated from each other by arcuate segments of the periphery of the otherwise disk-shaped valve element 50.
In contrast and referring briefly to
The valve elements of the present invention may be flat as shown, and may also include structure to stabilize and align the valving portion during operation.
In operation, when the coil 24 is not energized the rod 30 is urged against the valve element 50/54 by the spring 28 to distance the valve element from the valve seat 48, allowing fluid flow through the opening 46. On the other hand, the coil 24 when energized moves the plunger 26 and, hence, rod 30 away from the valve element 50/54 to allow fluid pressure to urge the valve element against the valve seat 48, closing the opening 46.
While the particular FAST RESPONSE CHECK CONTROL VALVE is herein shown and described in detail, it is to be understood that the subject matter which is encompassed by the present invention is limited only by the claims.
