Patent Application
20090095350
The invention relates to an actuator controlled, adjustable air intake valve for a variable compression engine.
Vehicle engines are well known and require an air supply. Igniting or firing a compressed mixture of air and fuel within engine cylinder compression chambers powers the vehicle. Some engines use spark plugs to fire the mixture, while other engines rely on the heat of compression.
Variable compression engines include multiple cylinders, and typically include an air intake for supplying air to the cylinders. Variable compression engines change the number of firing cylinders to alter the engine's power output. The vehicle may require less power at cruising speeds, and therefore fire fewer cylinders. Additional cylinders fire as the vehicle's power requirements increase.
Variable compression engines typically require more air when the number of firing cylinders increases. Accordingly, the air moving to the engine increases as the number of firing cylinders increases. Changing the air supply to the engine may affect the engine's sound. That is, the sound from the engine fluctuates with changes in the speed of air moving through the air intake. With a consistently sized air intake, the airspeed through the intake slows as the air requirements decrease, and as the air requirements increase the airspeed increases. Formerly, variable compression engines produced unpleasant sound characteristics at some combinations of air requirements and air intake size.
Some engines attempt to alleviate the unpleasant sound characteristics by including more than one air intake, which provides additional paths for air to reach the engine when air requirements increase. Including additional intakes adds cost and complexity to the engine. Other engines include a butterfly valve for metering airflow through the air intake. Butterfly valves are positioned within the flow of air, which may increase turbulence in the air supplied to the engine. Turbulence can undesirably decrease the engine's efficiency.
It would be desirable to vary the air supply to a variable compression engine without requiring additional air intakes or increasing turbulence in the air supply.
An example valve for controlling airflow to an engine includes an actuator with an actuator arm that moves between extended and retracted positions, and a valve housing defining an airflow passage extending between a first housing opening and a second housing opening. The airflow passage has an axis X. The example valve also includes at least one finger within the valve housing. Movement of the actuator arm causes radial movement of the finger relative to the axis X, and the finger moves between a position that provides a restricted flow of air through the airflow passage, and a position that provides a greater flow of air through the airflow passage.
An example actuator device for controlling a variable engine intake valve includes an actuator arm and an actuator for moving the actuator arm between a first position and a second position. A controller controls the position of the actuator arm. Moving the actuator arm to a first position causes a restricted airflow through an engine air intake valve and movement of the actuator to the second position causes a less restricted airflow through the engine air intake valve.
An example method of controlling airflow to an engine includes moving an actuator arm in a first direction to restrict airflow to an engine and moving the actuator arm in a second direction different from the first direction to permit greater airflow to the engine. The first and second directions are generally transverse to the airflow.
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description. The accompanying drawings can be briefly described as follows.
An example variable intake valve 10 includes an actuator 14 mounted adjacent an inner housing 18 and an outer housing 22, as shown in
The actuator arm 38 moves between an extended position (shown) and a retracted position. In the extended position, the actuator arm 38 extends further from the actuator 14 than the retracted position. The actuator arm 38 may be infinitely adjustable between the extended and retracted positions (e.g., electric actuator). Alternatively, the actuator arm 38 moves between two defined positions (e.g., vacuum actuator). Adjusting the position of the actuator arm 38 rotates the link 42 to change the cross-sectional flow area through the intake valve 10.
As shown in the cutaway view of
Referring now to the rear view of
The outer finger 46 also includes a slot 72 for receiving a driver pin 73 extending from a second inner finger 52. When the outer finger 46 pivots, the slot 72 presses against the driver pin 73 and forces the second inner finger 52 to pivot about pivot attachment 76. Thus, pivoting the outer finger 46 pivots both the inner fingers 50, 52.
The inner fingers 50, 52 mount adjacent a surface of the mounting plate 54 opposite the outer finger 46. In this example, the mounting locations of the inner fingers 50, 52 and the outer finger 46 arranged about the axis X. Another outer finger 48 mounts to the mounting plate 54 on the same side as outer finger 46. The mounting location of the inner fingers 50, 52 and the outer fingers 46, 48 are each offset to evenly distribute the fingers around the axis X.
The inner finger 50 includes driver pin 86 that extends past the mounting plate 54 into a slot 82 on the outer finger 48. The outer finger 48 moves with the driver pin 86 and the inner finger 50. The outer finger 48 also includes a driver pin 68 extending past the mounting plate 54 and received within a slot 71 on the second inner finger 52. As the second inner finger 52 pivots, the sides of the slot 71 press against the driver pin 68 to pivot the outer finger 48. Thus, the inner fingers 50, 52 combine to move the outer finger 48.
The inner fingers 50, 52 and the outer fingers 46, 48 have a similar shape and contain respective pivot points, driver pins, and slots. In one example, the fingers are formed of a molded polymer material cast from similar molds. The extension 58 may be molded-in and then removed from the fingers that do not need the feature. Alternatively, the extension 58 may be added after molding.
Pivoting the inner fingers 50, 52 and the outer fingers 46, 48 moves the fingers relative to the axis X to change the cross-sectional flow area through the valve 10. When less airflow to the engine 30 is desired, the actuator 14 retracts the actuator arm 38 to pivot the link 42 and move the inner fingers 50, 52, and outer fingers 46, 48 radially inward such that the flow cross-section of valve 10 is d, as shown in
The example valve includes fingers 46, 48, 50, 52 that include engagement features such that radial movement relative to axis X of one finger causes a similar radial movement of the remaining fingers. The outer fingers 46, 48 and inner fingers 50, 52 attach to opposing sides of the mounting plate 54, which includes features for further controlling movements of the outer fingers 46, 48 and inner fingers 50, 52. The features of the outer fingers 46, 48, inner fingers 50, 52, and mounting plate 54 are in one example pins 66, 68, 86 and slots 70, 72, 82, 78 Other example features may include extensions received within depressions or other suitable designs.
Although an example invention has been disclosed, a worker of ordinary skill in the art may recognize that certain modifications are possible that come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope of legal protection available.
