Patent Application
20070175442
This invention relates to an intake manifold system for an internal combustion engine.
The performance of an internal combustion engine can be optimized by adjusting the characteristics of its intake manifold as a function of the engine's operating condition. The characteristics of an intake manifold, such as its geometry, can be adjusted with one or more valves, such as charge motion control valves and resonance valves. Thus the performance of an international combustion engine can be optimized by controlling the valves of the engine's intake manifold.
Currently, the valves of an intake manifold are actuated with electric actuators or vacuum actuators. Each of the two types of actuators has several disadvantages. For example, an electric actuator is relatively expansive and difficult to accommodate in a tightly-packed engine compartment of a vehicle. A vacuum actuator requires a vacuum tank, which is also difficult to accommodate in an engine compartment.
An engine intake manifold system of the present invention overcomes some of the disadvantages associated with the electric and vacuum actuators. In accordance with one aspect of the present invention, an engine intake manifold system includes an intake manifold having a valve, and an actuator connected to the valve to control valve opening. The actuator is also connected to a pressurized coolant reservoir of the engine to allow the use of the pressurized fluid in the coolant reservoir to operate the actuator.
An intake manifold system of the present invention is relatively inexpensive when compared with an electric actuator, and easier to accommodated when compared with a vacuum actuator with a vacuum tank. The intake manifold system is also simple because it uses an existing power source—the pressurized coolant reservoir of the engine.
In a preferred embodiment, the actuator includes a housing, a diaphragm that sealingly divides the housing into first and second chambers, a rod that is connected to the diaphragm and extends to the exterior of the housing through the first chamber, and a spring urging the diaphragm towards the second chamber. The second chamber may be connected to the pressurized coolant reservoir to allow the use of pressurized fluid of the coolant reservoir to push the diaphragm towards the first chamber against the spring. The rod is connected to the valve to use the movement of the rod to control valve opening.
The intake manifold system may also include a control valve for controlling the pressure in the actuator to adjust the opening of the intake manifold valve. The control valve preferably is disposed in a flow path between the actuator and the pressurized coolant reservoir. In a preferred embodiment, the control valve may be used to control the pressure in the actuator's second chamber to adjust the opening of the intake manifold valve.
The intake manifold system may further include a pressure tank disposed between the actuator and the pressurized coolant reservoir, as well as a valve disposed between the pressure tank and the pressurized coolant reservoir. This valve closes or opens the flow path between the pressure tank and the pressurized coolant reservoir. With this arrangement, the valve opening can be adjusted to maintain a constant pressure in the pressure tank even when the pressure in the coolant reservoir fluctuates. Additionally, the pressure in the pressure tank can be maintained by closing the valve even when the engine is cold and the pressure in the coolant reservoir is low. An accumulator may be connected to the pressure tank to assist in the maintenance of tank pressure.
In a preferred embodiment, the pressure tank and the pressurized coolant reservoir are integrally formed. For example, they may be integrally formed by means of injection molding.
In accordance with another aspect of the invention, an engine intake manifold system includes the pressurized coolant reservoir of the engine, as well as the components described above. In other words, the pressurized coolant reservoir of the engine may be considered as a component of the intake manifold system, not a component to which the intake manifold system is connected.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
The intake manifold of the present invention may be an intake manifold of any type. For example, it may be an intake manifold for a V-8 engine or for a straight-4 engine. The intake manifold may also include more than one set of valves, and each additional set of valves can be operated by a separate actuator powered by the pressurized coolant reservoir. The valves can be, for example, barrel valves, charge motion control valves and/or resonance valves.
The actuator of the present invention may be any actuator that can use pressurized fluid to drive a valve shaft.
In operation, as the pressure in the second chamber 32 increases, the diaphragm 24 and rod 26 is pushed towards to the first chamber 30, and the spring 28 is further compressed. As the pressure in the second chamber 32 decreases, the diaphragm 24 and rod 26 is pushed towards to the second chamber 32 by the spring 28. Thus, the pressure increase and decrease in the second chamber 32 generates a linear movement of the rod 26, which in turn produces a rotational movement of the valve shaft 16.
The pressurized coolant reservoir 20 is known in the art and therefore will not be discussed in detail here. It just needs to be mentioned that when the engine is sufficiently warmed up, the reservoir 20 has a chamber that is filled with pressurized fluid (i.e., coolant and air). The pressurized fluid can be used as a power source for the actuator of the present invention.
As shown in
To simplify the operation of the control valve 34, it is desirable to provide the control valve 34 with a relatively constant supply pressure. The pressure in the pressurized coolant reservoir 20, however, varies with the engine operating condition. Thus it is desirable to provide an arrangement that maintains a relatively constant supply pressure to the control valve 34 in spite of the pressure variations in the pressurized coolant reservoir 20. In the embodiment shown in
This valve 38 can be used to maintain a relatively constant pressure in the pressure tank 36. For example, if the pressure in the pressure tank 36 is higher than the desired pressure, the valve 38 reduces its opening to reduce the flow of pressurized fluid from the pressurized coolant reservoir 20 to the pressure tank 36, thereby decreasing the pressure in the pressure tank 36. On the other hand, if the pressure in the pressure tank 36 is lower than the desired pressure, the valve 38 enlarges its opening to increase the flow of pressurized fluid into the pressure tank 36, thereby increasing the pressure in the pressure tank 36. Additionally, this arrangement can be used to maintain a pressure in the pressure tank 36 when the engine is shut off so that during an engine start-up when the pressure in the coolant reservoir 20 is low, the pressure in the pressure tank 36 can be used to control the intake manifold valve 14.
The arrangement may include an accumulator 40 connected to the pressure tank 36. The accumulator 40 can increase the pressure tank's ability to maintain the desired pressure.
The pressure tank 36 and the pressurized coolant reservoir 20 can be integrally formed, as shown in
The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.
This application claims priority from U.S. Provisional Patent Application No. 60/702,301, filed Jul. 26, 2005.
| Number | Date | Country | |
|---|---|---|---|
| 60702301 | Jul 2005 | US |
