I. Field of the Invention
The present invention relates generally to valves for vehicle hydraulic systems such as automatic transmission systems.
II. Background of the Invention
Modern vehicles have many control systems in which a controller, in response to sensor signals, actuates vehicle components to control the vehicle. As one illustration, an engine control module (ECM) might receive input from various sensors and in response turn “on” and “off” actuation coils of various hydraulic valves to cause an automatic transmission to shift.
Spool valves are one type of valve that can be used for hydraulic control purposes. The valves in essence control the flow or pressure of the hydraulic fluid through various fluid chambers by causing a spool to slide within a valve housing, opening and closing various ports in the housing as it does so. Typically, the ports include a supply port that is connected to a hydraulic fluid supply, an exhaust port that exhausts fluid back to the hydraulic fluid supply, and a control port that is connected to the component sought to be controlled, e.g., to a transmission component.
Conventional spool valve designs require tight tolerances between the spool outer diameter and the housing inner diameter, because the clearance between the spool outer diameter and housing inner diameter determines the fluid leakage and flow/pressure control performance of the valve. As understood herein, the requirement for maintaining tight tolerances increases the cost of the valve.
Additionally, it is important that the magnetic, mechanical and hydraulic forces in the valve are adequately managed to produce the desired pressure or flow output. The present invention recognizes that friction, hydraulic stiction, component misalignment, under-damping, and other factors ideally should be minimized in to reduce actuator performance variation and enhance part reliability. With the above recognitions in mind, the present invention is provided.
A valve includes a valve body defining at least one exhaust port, and may have an exhaust port at every end of the below-described column. The valve body also defines a supply port, and a control port, with the ports being aligned with each other. A plunger is at least partially disposed in the valve body and is reciprocally movable therein, and an actuating solenoid can be energized to cause the plunger to move. Plural balls are disposed in alignment in the valve body to establish a ball column. The plunger contacts a first end of the ball column, and the balls are movable in unison by the plunger between a closed configuration, wherein fluid communication between the supply and control ports is blocked, and an open configuration, wherein fluid communication between the supply and control ports is not blocked. A return spring is disposed in compression to push against the second end of the ball column.
If desired, a plunger assist spring can be disposed in compression to push against the first end of the ball column. In some implementations, a first ball in the column is smaller than a second ball in the column, with the first ball being circumscribed by an alignment ring and moving therewith. In specific non-limiting embodiments the ball column can include, in order from the plunger, the second ball, the first ball, a third ball having substantially the same diameter as the second ball, and a fourth ball having substantially the same diameter as the second ball, with each ball at all times contacting at least one adjacent ball. A spacer ring may be disposed intermediate the third and fourth balls.
In another aspect, a valve includes a valve body formed with at least supply, exhaust, and control ports. A column of rigid balls is movably disposed in the body and is juxtaposed with the ports, with each ball contacting at least one other ball in the column. Opposed force means are provided for selectively causing the column to reciprocate to establish a desired fluid flow configuration of the valve.
In still another aspect, a valve has a valve body formed with at least first and second ports, and an axially rigid port blocking structure includes plural independently movable segments. The port blocking structure is movably disposed in the body in juxtaposition with the ports. Opposed force means selectively cause the port blocking structure to reciprocate to establish a desired fluid flow configuration of the valve.
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:
The present invention is intended for application in automotive vehicle systems and will be described in that context. It is to be understood, however, that the present invention could also be successfully applied in many other applications.
Referring initially to
A plunger/rod assembly 28 is disposed in the valve body 12 and is movable therein under the influence of the actuating solenoid 14, which can be energized to cause the plunger/rod assembly 28 to move to the left looking down in
In the illustrative non-limiting embodiment shown, the column 36 of balls includes, from right to left, the right-most ball 40, a smaller ball 42, a ball 44, and the left-most ball 34, with the balls 34, 40, and 44 having substantially the same diameters as each other and with the small ball 42 having a relatively smaller diameter as shown. The balls 34, 40, 42, 44 are rigid and may be made of steel.
Accordingly, as shown in
It may now be appreciated that while the column 36 is axially rigid, the individual balls 34, 40, 42, 44 may rotate independently, decreasing friction as the column 36 moves. If desired, to maintain radial positioning the smaller ball 42 may be circumscribed by a hollow rigid alignment ring 46 (
While the particular VALVE WITH BALL COLUMN ACTUATION as herein shown and described in detail is fully capable of attaining the above-described objects of the invention, it is to be understood that it is the presently preferred embodiment of the present invention and is thus representative of the subject matter which is broadly contemplated by the present invention, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more”. It is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. WE CLAIM: