A vehicle typically includes a climate control system which maintains a temperature within a passenger compartment of the vehicle at a comfortable level by providing heating, cooling, and ventilation. Comfort is maintained in the passenger compartment by an integrated mechanism referred to in the art as a heating, ventilation and air conditioning (HVAC) air handling system. The air handling system conditions air flowing therethrough and distributes the conditioned air throughout the passenger compartment.
The air handling system commonly employs a housing including one or more heat exchangers for conditioning the air passing through the air handling system. The air handling system may for example include an evaporator associated with a refrigeration circuit of the air handling system for cooling and dehumidifying the air. The air handling system may further include a heating heat exchanger for heating the air passing through the air handling system. The heating heat exchanger may be a condenser associated with the refrigeration circuit or a radiator associated with a coolant system of the motor vehicle.
The heat exchangers are typically contained within an interior of the housing while additional components of the refrigeration circuit or the coolant system of the motor vehicle are disposed exterior to the housing, thereby requiring any fluids associated with the heat exchangers to be fed through one or more openings formed in an exterior portion of the housing. Each opening formed in the housing accordingly requires sealing to prevent the ingress or egress of fluids into or out of the housing.
FIGS. 1 and 2 illustrate one exemplary sealing structure 110 for sealing one or more openings 102 formed in an outer wall 104 of a housing 105 of an air handling system. The sealing structure 110 is formed of an elastomeric material and is configured to be compressed between the outer wall 104 of the housing 105 and a panel 106 having an opening 103 to prevent an incidence of fluid entering or exiting each of the openings 102.
The sealing structure 110 is shown as having a first face 111 and an opposing second face 112. A projection 114 extends from the first face 111 of the sealing structure 110. A central region of the sealing structure 110 surrounded by the projection 114 includes a plurality of fluid ports 101 for receiving various fluid conduits 120 configured to communicate fluid to components contained within the housing 105 such as an evaporator of a refrigerant circuit associated with the air handling system. The outer wall 104 of the housing 105 includes a plurality of spaced apart ribs 115 extending away from an outer surface of the outer wall 104. The outer wall 104 of the housing 105 may include the ribs 115 to add mechanical strength to the housing 105 at selected regions thereof, to prevent formation of sink marks when manufacturing the housing 105, and to provide a substantially planar surface for engaging the sealing structure 110.
FIGS. 3 and 4 illustrate one potential problem faced when employing the prior art sealing structure 110 of FIGS. 1 and 2 in conjunction with the panel 106 and the outer wall 104 of the housing 105 having the pattern of the ribs 115 formed thereon. The panel 106 includes a substantially planar face in facing relationship with the projection 114 of the first face 111 of the sealing structure 110 while the plurality of the ribs 115 form a pattern of spaced apart and projecting surfaces in facing relationship with the second face 112 of the sealing structure 110. The spacing of the ribs 115 from one another causes the second face 112 of the sealing structure 110 to encounter a plurality of spaced apart forces caused by the abutment of the ribs 115. The spaced apart forces are balanced by a substantially planar and distributed force applied by the abutment of the panel 106 to the first face 111 of the sealing structure 110. The spaced apart forces in turn cause each portion of the second face 112 of the sealing structure 110 encountering one of the ribs 115 to experience a greater force per unit of surface area than the substantially planar portion of the projection 114 of the first face 111 of the sealing structure 110 encountering the substantially planar surface of the panel 106. The ribs 115 in turn tend to deform the elastomeric sealing structure 110 by partially indenting the second face 112 of the sealing structure 110 at each abutment formed between the ribs 115 and the second face 112 of the sealing structure 110.
As shown in FIGS. 3 and 4, which illustrate cross-sectional views of the sealing structure 110 following compression of the sealing structure 110 between the ribs 115 of the outer wall 104 and the panel 106, the indenting of the second face 112 of the sealing structure 110 at each of the ribs 115 tends to cause the first face 111 of the sealing structure 110 in abutment with the panel 106 to form a corresponding indentation 125 at a position intermediate two of the ribs 115. The indentation 125 is formed as a result of a surface tension of the elastomeric sealing structure 110 causing the first face 111 thereof to take a shape corresponding to a shape taken on by the opposing second face 112 thereof. In the case illustrated in FIGS. 3 and 4, the waffle-like pattern of the ribs 115 causes a plurality of the indentations 125 to be formed in an intersecting grid-like pattern upon compression of the sealing structure 110. Such a pattern of gaps formed between the panel 106 and the sealing structure 110 by the presence of the indentations 125 may in turn lead to a decreased sealing effect achieved by compression of the sealing structure 110.
It would therefore be desirable to produce a sealing structure configured to prevent a formation of depressions at a first face of the sealing structure when the sealing structure is compressed between a planar and continuous surface engaging the first face and a plurality of spaced apart co-planar surfaces engaging an opposing second face of the sealing structure.