MOLDED INTAKE MANIFOLD WITH SEPARATE INLET ENTRY RUNNERS

Abstract: An intake manifold is molded of two plastic parts. A first main manifold body provides the outer cover and an inner opening. A second runner provides a plurality of entry ports for communicating air to cylinders within the engine. In the past, it has been somewhat difficult to control the shape of the entry ports when the manifold was molded of a single part. The use of the separate runner allows the provision of a relatively thin and easily molded part such that the entry ports can be closely controlled and an idealized design can be achieved.

Description: MOLDED INTAKE MANIFOLD WITH SEPARATE INLET ENTRY RUNNERS BACKGROUND OF THE INVENTION This application relates to a molded plastic intake manifold wherein entry ports are formed within a separate runner such that the ports can be formed as close as possible to an idealized configuration. Intake manifolds receive and distribute air to a number of cylinders within a vehicle engine. Historically, the intake manifold has been formed of metal. More recently, manifolds have been molded from plastics. One portion of the intake manifolds that is the subject of much design effort is the configuration of the entry ports leading from the manifold into engine cylinders. The entry ports typically have a closely designed curved surface intended to smoothly guide airflow into the engine cylinders. The prior art formed the entry ports and the overall manifold body as a single molded part. It is difficult to achieve entry ports having the exact desired shape from a single molded part. SUMMARY OF THE INVENTION In a preferred embodiment of this invention, a molded plastic intake manifold is formed having a main inlet manifold body formed as a first part, and entry ports molded as a separate part. Preferably, the entry ports are formed in a runner which creates a number of the entry ports with a single part. The runner and the main body part are connected together to form the manifold. Since the runner is a relatively small and relatively flat item, the configuration of the entry ports can be closely controlled. Entry ports having the exact desired configuration can be achieved. In one embodiment, the entry ports are formed in a runner including half portions of the ports. The other half of the port is formed within the main manifold body. One disclosed embodiment includes two separate runners, with the two separate runners positioned on opposed sides of the main manifold body. In a more preferred embodiment, the runner has connecting webs connecting the runners on each side of the manifold. Further, the runners preferably define the entire entry port. The runners may be pinned to the main manifold body, and then welded. In the preferred embodiment, the runner rests on a ledge on the manifold body before being welded. Although plastic welding is the preferred method of attaching the two, other attachment methods may be utilized. These and other features of the present invention will be best understood from the following specification and drawings, the following of which is a brief description. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 A shows an intake manifold sitting atop a vehicle cylinder. Figure IB shows the inner surface of a molded plastic intake manifold. Figure 2 shows a runner body as is part of the Figure IB embodiment. Figure 3 shows the interior of the manifold body of a second embodiment. Figure 4 shows a side of a preferred runner which will face the engine. Figure 5 shows the opposed side of the runner of Figure 4. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT As shown in Figure 1A, a vehicle engine 15 incorporates an engine block which receives an intake manifold 16. The intake manifold is preferably molded of plastic, and the structure of the intake manifold is shown in Figure IB. As shown in Figure IB, the intake manifold 20 incorporates an outer manifold body 22 and a runner 24. The runner 24 includes a plurality of entry ports 26 which are positioned above cylinders in the engine 15, as known. Connecting webs 28 connect the plurality of ports 26. In this embodiment, an inner wall 30 of the main body 22 provides a portion of the entry port along with a curved surface 32 on the runners 24. As can be appreciated from Figure 2, the runners 24 are relatively flat parts. Due to the relatively flat shape, the runners 24 can be easily molded such that the shape of the entry port 32 can be closely controlled. As mentioned above, in the field of engine design, it is known that a specific shape would be desired for the ports 32. In the past, it has been somewhat difficult to achieve the specific shape with the one-piece molded plastic intake manifolds. The inventive use of a separate intake manifold runner allows the control of the molding process to provide the specific shape. The runners shown in Figure 2 have structure such as shown at 28 to receive a pin from the main body, such that the runner can be supported on the main body 22 until being welded. Vibration or ultrasonic welding techniques may be used. Other means of attaching the runner to the main body may be utilized. Figure 3 shows the interior of a main body 40 for a preferred embodiment. As shown, a ledge 41 will support a runner 43 shown in Figure 4. Figure 4 shows the surface which faces the engine, and having entry ports 44. As shown, webs 42 connect the opposed ports 44, such that a single run piece 43 provides the runners for both sides of the manifold. As in the prior embodiment, adjacent ports are also connected by a web 45. As shown in Figure 4, the surface of the part 43 which will face into the manifold body 40 looks somewhat similar to the earlier embodiments. As with the prior embodiment, the structure 44 of the entry port can be closely designed and the relatively thin molded part allows the specific shape desired to be achieved. With this embodiment, the runner 43 can be merely placed on the ledge 41 of the main body 40, and welding then performed. In this way, a combined intake manifold and runner body is provided. The use of the relatively thin runners allow close control to achieve a desired and ideal shape for the various curved surfaces leading into the entry ports. As such, the present invention allows use of the plastic molding to provide a part which has not been capable of idealized plastic molding in the past. Preferred embodiments of this invention have been disclosed, however, a worker in this art would recognize that certain modifications would come within the scope of this invention. For that reason the following claims should be studied to determine the true scope and content of this invention.

Claims: CLAIMS 1. A plastic intake manifold comprising: a main manifold body including an outer cover surface and an opening for being mounted on an engine; and a separate runner, said runner defining a plurality of entry ports for communicating air to cylinders on an engine block, said runner and said main body being each molded as separate pieces from plastic and then secured together. 2. A manifold as recited in Claim 1, wherein there are runners on each of two opposed sides of said main body, and each of said runners being molded as separate parts. 3. A manifold as set forth in Claim 2, wherein each of said runners include a plurality of entry ports, with webs connecting each of said plurality of ports in each of said runners. 4. A manifold as set forth in Claim 2, wherein said entry ports are only partially defined by said runner, with the surface on said main body defining a portion of said entry port. 5. A plastic manifold as set forth in Claim 1, wherein runners are provided on each side of said main manifold body, and said runners being connected by webs between said two runners such that a single runner body provides entry ports on each of two sides of said manifold body. 6. A method of providing a molded intake manifold comprising the steps of: 1) molding a main manifold body having an outer cover and an inner opening; 2) molding a runner body, said runner body being relatively thin and defining a plurality of entry ports; 3) connecting said runner body to said main manifold body. 7. A method as set forth in Claim 6, wherein said runners are provided at each of two opposed sides of manifold body, and there being separate runners each separately molded and connected to said manifold body. 8. A method as set forth in Claim 6, wherein there are entry ports provided on each of two sides of said manifold body, and a single runner provides entry ports at said opposed sides of said manifold body. 9. A method as set forth in Claim 6, wherein said molded manifold and runner is then attached to a vehicle engine.

Inventors: MAMMARELLA JOHN R, MAMMARELLA, JOHN, R.
Applicants: SIEMENS CANADA LTD, SIEMENS CANADA LIMITED
Application year: 2000
Main classification: F02M35
IPC codes: F02M35