Patent Application
20080163844
The present invention relates to an air intake system for an internal combustion engine of a motor vehicle.
The air intake manifold of an internal combustion engine channels intake air from the engine's throttle body to the combustion chambers. A typical intake manifold, which can be mounted to a cylinder head of the engine, comprises a plenum and a plurality of runners that distribute airflow from the plenum to the intake ports of each cylinder. For a given air intake manifold, engine performance (e.g., the location of an engine's torque peak in the RPM band) is a function of the volume of the plenum, the cross-sectional area of the runners and, to a lesser extent, the length of the runners.
Conventional air intake manifolds have a fixed air flow geometry. With a fixed air flow geometry, the speed at which intake tuning occurs is also fixed, and the design of such air intake manifolds usually involves a compromise between achieving adequate torque at low speeds and sufficient horsepower at high speeds. In a tuned manifold, for example, the plenum volume, the length of the runners, and the cross-sectional area of the runners can be selected so that a pressure wave formed within the runners has a frequency that optimizes the pressure at each intake port when the corresponding intake valve is open.
One variable used to select the size and dimension of both the plenum and the runners is the engine volume (i.e., the engine displacement). For example, automobile engines can range in size from 2 liter, 4-cylinder models, to 6 liter or even larger 8-cylinder models. The total volume of an air intake manifold, which includes the volume of the plenum and the volume within the runners, is typically about twice the total engine displacement. Because the volume of an air intake manifold is proportional to the engine displacement, a different air intake manifold design is required for each engine size. This relationship results in a large number of different air intake manifold designs and the attendant expense associated with their design and manufacture.
Accordingly, it would be an advantage if a single air intake manifold design could be adapted to fit multiple engine sizes, thus reducing the required number of different air intake manifold designs.
It is an object of the invention to provide a modular air intake manifold assembly.
Another object of the invention is to provide an air intake manifold configured to have one of a plurality of different internal volumes.
A further object of the invention is to provide an economical air intake manifold.
The air intake manifold of the invention has fitted therein a rigid, volume-reducing insert. The insert, which is preferably a cylindrically-shaped insert, can have any of a variety of cross-sectional shapes along its axial dimension, including circular, oval, square or rectangular. The insert is permanently fitted within the plenum of the air intake manifold and can be sized to produce different plenum volumes for a given air intake manifold design.
According to one embodiment, an air intake manifold assembly comprises a plurality of shell pieces bonded together to define a plenum volume and an insert bonded to an inner surface of one or more of the shell pieces to form a dead space between the insert and the inner surface of the shell pieces.
According to a further embodiment, a method of forming an air intake manifold assembly includes bonding an insert to an inner surface at least one shell piece to define a dead space between the insert and a portion of the inner surface of the at least one shell piece, and bonding the at least one shell piece to one or more shell pieces to form a plenum volume therebetween such that the insert is positioned within the plenum volume.
These and other features of preferred embodiments of the invention, in addition to being set forth in the claims, are also disclosed in the specification and/or in the drawings, and the individual features each may be implemented in embodiments of the invention either individually or in the form of sub-combinations of two or more features and can be applied to other fields of use and may constitute advantageous, separately protectable constructions for which protection is also claimed.
The invention will be described in further detail hereinafter with reference to illustrative preferred embodiments shown in the accompanying drawings in which:
The air intake manifold 110 is fabricated using a multi-shell construction and comprises shell piece 112. Two or more shell pieces (not illustrated) can be bonded together to define the air intake manifold 110. As is conventionally known, respective mating pairs of the shell pieces can be bonded together along respective interfaces using a welding process such as vibrational welding.
Referring to
A rigid, non-porous insert 150 is fitted within the plenum to reduce the air volume therein. By forming a seal between the insert 150 and at least one shell piece, a dead space 160 is formed between the insert and the shell piece. According to one embodiment, the insert 150 is fitted within the inlet region of the plenum. Illustrative inserts are shown in
The insert 250 also includes a pair of sealing surfaces 260, 280. According to the
An insert 350 according to another embodiment is shown in
The sealing surfaces of an insert are configured to mate with and be bonded to an inner surface of one or more of the shell pieces (e.g., shell piece 112 or 114) that define the plenum. For example, the sealing surfaces of an insert can be bonded to flanged inner surfaces 124 of the plenum. When the air intake manifold is assembled, the insert is secured within the plenum 120. By bonding the insert within to an inner wall of the plenum, a dead space is formed between the insert and the inner wall. Thus, the plenum volume can be reduced by an amount substantially equal to the volume of the dead space.
The invention has the advantage that by using inserts of different size, the volume of the plenum can be adjusted during manufacture of the air intake manifold without modification to the design of the shell pieces. By way of example, an air intake manifold having a total volume suitable for use with a 2.4 liter engine can be easily adapted for use with a 2.2 or 2.0 liter engine by using an appropriately-sized insert.
Permanent bonding of the insert to one of the shell pieces can be accomplished using a welding process such as vibrational welding, friction welding, ultrasonic welding or the like. Each of the shell pieces and the insert are preferably made of a synthetic resin material or of a light metal such as aluminum or an alloy of aluminum. A suitable process for forming the shell pieces and the insert is injection molding.
According to a preferred embodiment, the diameter of the insert's inner bore 254, 354 is greater than or equal to the diameter of the intake conduit 116 so that air flow into and through the plenum is not substantially restricted by the insert.
The foregoing description and examples have been set forth merely to illustrate the invention and are 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 broadly to include all variations falling within the scope of the appended claims and equivalents thereof.
| Number | Date | Country | |
|---|---|---|---|
| 60878665 | Jan 2007 | US |
