Patent Application
20160215738
Not Applicable.
Not Applicable.
The present invention relates in general to intake manifolds for combustion engines, and, more specifically, to apparatus for introducing secondary gases into the main fuel/air mixture passing through the intake manifold.
Intake manifolds for internal combustion engine are commonly formed out of a polymeric material. In an effort to reduce noise radiating from the surface of the intake manifold due to resonant frequencies set up at particular engine speeds, it is known to provide internal and external bracing on the surface of the manifold and to provide internal posts formed out of the parent material. The internal posts traverse through the plenum cavity within the manifold, and are typical formed as indentations in upper and lower shell members. Each indentation penetrates the plenum cavity with a tunnel wall and a terminus wall. The terminus walls of the upper and lower shell members are friction welded together at the same time that outer flanges of the shell members are welded together.
Any internal structure, such as the posts, may reduce the flow area within the intake manifold which can limit the peak power of the engine. It may be possible to increase the size of the intake manifold to overcome the drop in flow area due to internal structures, but with a corresponding increase in overall size of the manifold which increases cost and weight and complicates packaging.
One additional internal structure may include features for introducing secondary gases into the intake manifold for distribution to the engine cylinders. Secondary gas sources may include an exhaust gas recirculation (EGR) system, a positive crankcase ventilation (PCV) system, and a fuel tank vapor recovery system. Ports (including tubes and injection channels) may obstruct or disrupt air flow within the manifold, especially when several such ports are deployed. Furthermore, limited space availability can result in attempting to locate ports in cramped spots which makes attachment to external devices difficult or results in interference with other components attached to the manifold.
The invention integrates a secondary gas port into a bracing post which may optimize the distribution of secondary gases while minimizing obstructions and decreasing manufacturing cost.
In one aspect of the invention, an intake manifold comprises upper and lower shell members. The upper shell member has an outer flange. The lower shell member has an outer flange joined to the outer flange of the upper shell member to define a manifold cavity having a plenum and a plurality of runners. The upper shell includes an upper post formed as an indentation into the plenum with a tunnel wall and a terminus wall. The lower shell includes a lower post formed as an indentation into the plenum with a tunnel wall and a terminus wall. The terminus walls are attached to provide a brace across the plenum. One of the posts includes an orifice penetrating the tunnel wall. A sealed coupler extends from the one post and is adapted to receive a secondary gas for mixing within the plenum.
Referring to
Post 20 has an upper post section 21 formed as an indentation 22 into an outer surface of plenum section 15. Post 20 has a lower post section 23 formed as an indentation into an outer surface 24 of lower shell member 12. Flanges 17 and 18 are coupled together in a friction welding process, during which adjacent ends of post sections 21 and 23 are friction welded, thereby creating a single substantially rigid post 20 extending between upper shell member 11 and lower shell member 12. Additional posts such as a post 25 can be assembled in the same manner. Secondary gas ports can be integrated in more than one of the posts, but one such port will normally provide enough gas capacity. Multiple ports may be useful when there is a desire to inject secondary gas at various different locations in relation to the runners.
An upper or lower post in a shell member provides an advantageous site for locating a secondary gas port, especially a post which is located toward an upstream end of a plenum section near the main inlet of the intake manifold. As shown in
A secondary gas port is shown in greater detail in
In order to compress seal 60 and maintain sealed coupler 56 in its desired inserted position within tunnel wall 51, a bracket 62 may be employed. A flange 63 extending from body 57 bears against bracket 62. Bracket 62 has a first end 64 captured over a post 65 on upper shell member 50 and has a second end 66 fastened to ii) upper shell member 50 by a fastener (e.g., screw) 67. Many other attachment methods such as bonding or other types of fastening will occur to those skilled in the art.
By integrating a secondary gas port into a structural post of the intake ii) manifold as disclosed above, the present invention achieves improved flow as a result of lowering the internal obstructions to flow. The invention can be manufactured at low cost using well established processes. In particular, a polymeric upper shell member can be molded with known materials having an outer flange and an upper post section formed as an indentation with a tunnel wall and a terminus wall. A polymeric lower shell member is also molded having an outer flange and a lower post section formed as an indentation with a tunnel wall and a terminus wall. The upper and lower shell members can be friction welded at the outer flanges and at the terminus walls to define a plenum with the joined post sections providing a brace across the plenum reducing vibrations. The tunnel wall of one of the shell members includes an orifice (e.g., as a result of the original molded shape or formed by a secondary operation such as drilling). A sealed coupler is mounted to the shell member so that it extends from the post section of the one shell member adapted to convey a secondary gas through the orifice for mixing within the plenum.
