Patent Publication Number: US-8122864-B2

Title: Intake manifold for multicylinder internal combustion engine

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     None. 
     BACKGROUND OF THE DISCLOSURE 
     1. Field of the Disclosure 
     The present disclosure relates to a manifold for conducting charge air to cylinders of an internal combustion engine. 
     2. Related Art 
     Intake manifolds have been used for many years with multicylinder internal combustion engines. Because air usually enters an engine at a single point, given that the mass flow of air through an engine must be known, so as to permit controlling the air fuel ratio correctly to promote proper post-combustion treatment of exhaust gases, manifolding is typically used. Engine designers have been very careful to seal around the various passages through an intake manifold at the point where the manifold is attached to the cylinder head of an engine, so as to prevent air from passing from one inlet runner to another. Unfortunately, such sealing is expensive in terms of materials and also may cause excess weight because the engine designers must assure that solid surfaces are available in connection with both the intake manifold and the mating cylinder head to support a sealing capability. 
     It would be desirable to provide an intake manifold system which does not need sealing between adjacent runners and which provides opportunity for weight reduction and material cost reduction. 
     SUMMARY 
     According to an aspect of the present disclosure, an intake manifold for a multicylinder internal combustion engine includes a number of inlet runners and a cylinder head mounting flange operatively connected with the runners, with a sealing region circumscribing only an outer periphery of the mounting flange. The sealing region does not extend between adjacent ones of the runners. In a preferred embodiment, the sealing region includes a continuous groove formed in the intake manifold&#39;s mounting flange, with a sealing composition applied to the groove. The sealing region may be configured as a continuous loop without cross-linking. 
     According to another aspect of the present disclosure, a sealing composition used with the present intake manifold may include either a pre-formed elastomeric gasket or a formed-in-place elastomeric gasket, or yet other types of gaskets known to those skilled in the art and suggested by this disclosure. 
     According to another aspect of the present disclosure, a sealing composition applied as a continuous loop to an outer periphery of the mounting flange prevents leakage of air past the mounting flange and into the engine, while permitting some air exchange between adjacent ones of the manifold&#39;s inlet runners. 
     According to another aspect of the present disclosure, an intake manifold may include a number of relief regions configured in a mounting flange and a cylinder head of the engine, with the relief regions being positioned between adjacent ones of the inlet runners. 
     It is an advantage of an intake manifold according to the present disclosure that a reduction in material cost, in the form of sealants and gaskets, is achieved, while at the same time reducing processing costs by removing the need for milling or machining a gasket groove between adjacent runners on the intake manifold&#39;s mounting flange. 
     It is yet another advantage of an intake manifold according to the present disclosure that weight savings are possible because intake manifold and cylinder head material is eliminated by creating weight and material saving voids extending partially between adjacent runners of the intake manifold and ports of the cylinder head. 
     Other advantages, as well as features of the present system, will become apparent to the reader of this specification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partially schematic representation of an intake manifold according to an aspect of the present disclosure. 
         FIG. 2  is a partially schematic representation of a portion of an intake manifold and cylinder head according to an aspect of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in  FIG. 1 , an intake manifold,  10 , has a plenum,  12 , and throttle,  22 , which feed charge air to a number of inlet runners,  14 . Inlet runners  14  are operatively connected with a cylinder head mounting flange,  18 , which is shown in  FIG. 2  as being sealed to a cylinder head,  36 , having a number ports,  37 , formed therein, with ports  37  matching with runners  14  contained in intake manifold  10 . 
       FIG. 1  further discloses cylinder head mounting flange  18  as having a cylinder head engaging surface,  20 , which bears a sealing region,  26 . Sealing region  26  includes a sealing composition  34  applied to a continuous groove,  30 , which extends in a continuous loop about an outer periphery of mounting flange  18 . Notice from  FIG. 1  that there is no cross-linking of sealing region  26  extending between adjacent runners  14  within cylinder head engaging surface  20  of mounting flange  18 . Accordingly, as noted above, there is no need to machine the areas between the adjacent ones of the runners to accommodate a cross-linking or ladder bar gasketing or sealing composition. As shown in  FIG. 1 , sealing region  26  passes inboard of a number of fastener apertures  46  formed in mounting flange  18 , so as to prevent air leakage around fasteners. 
     Those skilled in the art will appreciate in view of this disclosure that the present charge air system could be rendered in several different materials commonly employed for automotive intake manifolds. These included, without limitation, metals, such as aluminum and magnesium, plastics, and composites. Although some plastics are subject to a creep phenomenon which could increase cross talk between adjacent runners by opening up the airflow crevice space between runners, it is believed that with commonly employed engineering plastics such an increase will have a negligible effect upon the induction tuning of an engine equipped with the present inventive system. 
       FIG. 2  shows two relief regions, with a first region,  38 , formed in cylinder head mounting flange  18 , and with a second relief region,  42 , formed in cylinder head  36 . In the interest of clarity, mounting flange  18  is shown as being separated slightly from cylinder head  36 . In any event, those skilled in the art will appreciate in view of this disclosure that the precise configurations of relief regions  38  and  42  may be determined according to the precise architectures employed for cylinder head  36  and intake manifold mounting flange  18 . What is important is that relief regions  38  and  42  save material, while also reducing cost and weight. This is possible because sealing region  26  is not cross linked and therefore does not extend through the contiguous space occupied by relief regions  38  and  42 . 
     The foregoing system has been described in accordance with relevant legal standards, thus the description is exemplary rather than limiting in nature. For example, the present system may be employed between an upper and a lower intake manifold. This and other variations and modifications to the disclosed embodiment may become apparent to those skilled in the art and fall within the scope of the disclosure. Accordingly the scope of legal protection afforded can only be determined by studying the following claims.