Fluid handling – Systems – Multi-way valve unit
Reexamination Certificate
2000-04-26
2001-01-09
Rivell, John (Department: 3753)
Fluid handling
Systems
Multi-way valve unit
C137S625650, C251S031000, C251S129070, C251S129100, C123S458000, C091S466000
Reexamination Certificate
active
06170524
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The principal utility of the invention is with valve and actuator applications where extremely fast response is very desirable. For example, a piston engine that needs to introduce fuel through direct injection within 30 degrees of crank rotation and that is running at 4000 rpm, has 1.25 milliseconds to open the fuel injection valve, inject the fuel and close the valve. The most apparent field of application is in internal-combustion engines for motor vehicles.
2. Description of the Prior Art
The growing utilization of automobiles has greatly added to the atmospheric concentration of various pollutants including oxides of nitrogen and greenhouse gases such as carbon dioxide. In a quest for approaches which could significantly improve the efficiency of fuel utilization for automotive powertrains, while still achieving low levels of NOx emissions, the need for fast valves and actuators became apparent and this invention was conceived.
Conventional “fast” valves begin a valving change from either an open or closed position. In the closed position the “movable component” of the valve has “sealed” (usually against a seat or, in a spool valve, by positioning the spool so that flow from the high pressure port is blocked). A command to open results in a force being applied to the movable component, and movement (i.e., acceleration) of the mass of the movable component begins according to the following equation:
F
M
=
a
Where:
“F” is the force applied to the movable component
“M” is the mass of the movable component
“a” is the acceleration of the movable component that results
The time required to move the movable component from the closed position to the fully open position is the time needed for valve opening, and this time is dependent on the acceleration and the distance the movable component must cover from the closed position to the fully open position. Conventional “fast” valves maximize acceleration by applying a very large force, minimize the mass of the movable components and minimize the travel distance by valve design to the extent possible. Extremely fast valve action (e.g., less than 1 millisecond) is therefore very difficult to achieve with conventional designs. Conventional valve designs begin the opening stage with an initial speed of zero. The acceleration rate results in a maximum speed that occurs at the end of the opening process. The average speed is therefore determined by the initial speed (i.e., zero) and the final speed, and for a near constant acceleration rate the average speed is about one half the final speed. Since the time for opening a conventional valve is the distance needed for travel to fully open the flow ports divided by the average speed, starting the valve opening from zero speed severely constrains the ability to obtain very fast valve openings.
In a conventional spool valve the “OFF” position has the spool valve port slightly withdrawn from communication with the passage through the valve body in order to provide a seal against leakage. See, for example, U.S. Pat. No. 4,770,389 issued to Bodine. This conventional sealing distance is not intended to allow the valve spool to accelerate prior to starting to open and, in fact, acceleration through a sealing zone in a conventional valve is de minimus, i.e., to less than 10% of maximum spool velocity.
In some modern “fast acting valves”, the leading edge of the valve port and that of the valve body passage are “line-on-line” in the OFF position. In other words, the leading edges of the two ports are radially aligned with no sealing distance therebetween. In such valves some small amount of leakage is tolerated in order to provide a faster acting valve.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a valve mechanism which starts the valve port opening at a high initial speed and finishes the port opening near or above this high initial speed then goes through a deceleration zone, thus significantly reducing the time required for opening (and closing) the valve.
Another object of the present invention is to achieve the above-stated objective by a unique valve design which provides acceleration and deceleration zones to provide extremely fast valve opening and closing.
A third object of the present invention is provision of a unique, two-way spool valve incorporating the desired acceleration/deceleration features described above.
A fourth object of the present invention is provision of a unique, three-way spool valve incorporating the desired acceleration/deceleration features described above.
A fifth object of the present invention is provision of a unique control valve for a two-way actuator incorporating the desired acceleration/deceleration features.
A sixth object of the present invention is provision of a unique, two-way cartridge valve incorporating the desired acceleration/deceleration features.
A seventh object of the present invention is provision of a unique fuel injection (or fluid control) system utilizing two valves, having the desired acceleration/deceleration characteristics, for each injector and an appropriately sized high pressure fuel supply line, or line with a flow restrictor such as an orifice.
An eighth object of the present invention is provision of a unique gas flow control valve which a control valve having the desired acceleration/deceleration characteristics, a fast, hydraulic actuator and, integrated with the hydraulic actuator, a poppet valve also having the acceleration/deceleration characteristics of the present invention.
A ninth object of the present invention is provision of a new means for utilizing multiple solenoids in series to maximize and maintain the accelerating force on the movable component (valve member).
A tenth object of the present invention is provision of a unique solenoid actuated valve providing the acceleration/deceleration characteristics of the present invention.
The unique design and operation of this new valve are based on utilization of acceleration and deceleration zones to achieve very fast valve response. The valve provides a zone (i.e., distance) wherein the movable component can be accelerated to a high speed of at least 30% of its maximum velocity before the movable component starts the valve port opening. Therefore, the valve port opening occurs in the shortest time possible. A second zone (i.e., distance) is provided for deceleration of the movable component and this second “deceleration” zone also serves as the acceleration zone for the reverse action of the valve (i.e., closing).
More specifically, in one embodiment the present invention provides a fast-acting valve including a valve body and a valve spool slidably mounted in a bore within the valve body for reciprocating movement in a linear path between first and second limit (rest) positions, i.e. between fully closed and fully open positions. The valve body and the valve spool both have at least one flow passage which align in the valve open position. The flow passage through the valve body is spaced from the one spool fluid flow passage with the valve spool in the fully closed position by a distance including an acceleration zone and a deceleration zone. The acceleration zone may be defined as the distance through which the valve spool accelerates before the one spool fluid flow passage reaches a position initiating fluid communication between it and the one valve body flow passage, i.e. a position where the leading edge of valve spool flow passage enters the one valve body flow passage, whereby the flow passage is very quickly opened. This acceleration zone is significantly longer than the distance required for sealing. The deceleration zone is the distance through which the valve spool decelerates before coming to rest in the fully open position. The fact acting valve of the present invention further includes first and second acceleration/deceleration means for alternately accelerating and decelerating the valve spool in travel between the fully open and fully closed rest positi
Lorusso & Loud
Rivell John
Schoenfeld Meredith H
The United States of America as represented by the Administrator
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