RELIEF VENT FOR HEATING VENTILATION AND AIR CONDITIONING SYSTEM

A pressure relief valve includes a housing configured for installation into a duct opening of a duct, and a diffuser installed into the housing and movable between a closed position and an opened position along a valve axis. The diffuser includes a tubular diffuser body having an inlet opening at a first end, a diffuser cap located at a second end of the tubular diffuser body to close the tubular diffuser body at the second end, and one or more outlet openings located between the inlet opening and the diffuser cap. A biasing element biases a position of the diffuser toward the closed position. When an airflow pressure in the duct exceeds a threshold, the airflow urges the diffuser toward the opened position thus allowing the airflow to exit the pressure relief valve at the one or more outlet openings.

INTRODUCTION

The subject disclosure relates to heating, ventilation and air conditioning of a vehicle. In particular, the present disclosure relates to control of airflow out of vents in the vehicle. Vehicles have multiple air vents in, for example, an instrument panel of the vehicle to distribute conditioned airflow into the passenger compartment of the vehicle. These vents typically use slide levers to move one or more sets of louvers or doors inside the vent to change the side-to-side and/or up-down direction of the airflow. With styling changes to vehicle interiors, the use of slim profile vents is increasing in usage. The use of such slim profile vents, however, may increase a resistance in the system, thus reducing an amount of airflow into the cabin. It is desired to reduce this resistance in order to improve the airflow into the vehicle cabin and quickly condition the airflow.

SUMMARY

In one exemplary embodiment, a pressure relief valve includes a housing configured for installation into a duct opening of a duct, and a diffuser installed into the housing and movable between a closed position and an opened position along a valve axis. The diffuser includes a tubular diffuser body having an inlet opening at a first end, a diffuser cap located at a second end of the tubular diffuser body to close the tubular diffuser body at the second end, and one or more outlet openings located between the inlet opening and the diffuser cap. A biasing element biases a position of the diffuser toward the closed position. When an airflow pressure in the duct exceeds a threshold, the airflow urges the diffuser toward the opened position thus allowing the airflow to exit the pressure relief valve at the one or more outlet openings.

In addition to one or more of the features described herein, the biasing element is a spring located between the tubular diffuser body and the housing.

In addition to one or more of the features described herein, the biasing element is a flexible biasing tab extending from the tubular diffuser body and interactive with the housing.

In addition to one or more of the features described herein the biasing element is a biasing ring located between the housing and the tubular diffuser body having one or more compressible portions.

In addition to one or more of the features described herein, a seal ring is operably connected to the duct and the housing.

In another exemplary embodiment, a heating, ventilation and air conditioning (HVAC) system of a vehicle includes an HVAC unit, a primary duct operably connected to the HVAC unit, a vent operably connected to the HVAC unit and configured to convey an airflow from the HVAC unit into an occupant compartment of the vehicle via the primary duct, and a pressure relief valve located along the primary duct. The pressure relief valve is configured to open when a pressure of the airflow in the primary duct exceeds a threshold to divert a portion of the airflow through the pressure relief valve. The pressure relief valve includes a housing installed into a duct opening, and a diffuser installed into the housing and movable between a closed position and an opened position along a valve axis. The diffuser includes a tubular diffuser body having an inlet opening at a first end, a diffuser cap located at a second end of the tubular diffuser body to close the tubular diffuser body at the second end, and one or more outlet openings located between the inlet opening and the diffuser cap. A biasing element biases a position of the diffuser toward the closed position. When the pressure of the airflow exceeds the threshold, the airflow urges the diffuser toward the opened position thus allowing the airflow to exit the pressure relief valve at the one or more outlet openings.

In addition to one or more of the features described herein, a secondary duct connects the pressure relief valve to the primary duct.

In addition to one or more of the features described herein, the pressure relief valve is located at a top pad of an instrument panel of the vehicle.

In addition to one or more of the features described herein, the biasing element is a spring located between the tubular diffuser body and the housing.

In addition to one or more of the features described herein, the biasing element is a flexible biasing tab extending from the tubular diffuser body and interactive with the housing.

In addition to one or more of the features described herein, the biasing element is a biasing ring located between the housing and the tubular diffuser body having one or more compressible portions.

In addition to one or more of the features described herein, a seal ring is operably connected to the duct and the housing.

In yet another exemplary embodiment, a vehicle includes a vehicle body defining an occupant compartment inside the vehicle, and a heating, ventilation and air conditioning (HVAC) system. The HVAC system includes an HVAC unit, a primary duct operably connected to the HVAC unit, a vent operably connected to the HVAC unit and configured to convey an airflow from the HVAC unit into the occupant compartment of the vehicle via the primary duct, and a pressure relief valve located along the primary duct. The pressure relief valve is configured to open when a pressure of the airflow in the primary duct exceeds a threshold to divert a portion of the airflow through the pressure relief valve. The pressure relief valve includes a housing installed into a duct opening, and a diffuser installed into the housing and movable between a closed position and an opened position along a valve axis. The diffuser includes a tubular diffuser body having an inlet opening at a first end, a diffuser cap located at a second end of the tubular diffuser body to close the tubular diffuser body at the second end, and one or more outlet openings located between the inlet opening and the diffuser cap. A biasing element bias a position of the diffuser toward the closed position. When the pressure of the airflow exceeds the threshold, the airflow urges the diffuser toward the opened position thus allowing the airflow to exit the pressure relief valve at the one or more outlet openings.

In addition to one or more of the features described herein, a secondary duct connects the pressure relief valve to the primary duct.

In addition to one or more of the features described herein, the pressure relief valve is located at a top pad of an instrument panel of the vehicle.

In addition to one or more of the features described herein, the biasing element is a spring located between the tubular diffuser body and the housing.

In addition to one or more of the features described herein, the biasing element is a flexible biasing tab extending from the diffuser body and interactive with the housing.

In addition to one or more of the features described herein, the biasing element is a biasing ring located between the housing and the diffuser body having one or more compressible portions.

In addition to one or more of the features described herein, a seal ring is operably connected to the duct and the housing.

DETAILED DESCRIPTION

In accordance with an exemplary embodiment, illustrated inFIG.1is an embodiment of a vehicle1. The vehicle1includes a vehicle body2, which defines an occupant compartment3in an interior of the vehicle1. As shown inFIG.2, the occupant compartment3includes an instrument panel10extending across the occupant compartment3. The occupant compartment3is conditioned to be heated or cooled via a heating, ventilation and air conditioning (HVAC) system12(shown inFIG.1), with conditioned airflow into the occupant compartment3via one or more vent assemblies14located in the instrument panel10. While the vent assemblies14are described herein as being located in the instrument panel10, one skilled in the art will readily appreciate that the vent assemblies14may be additionally or alternatively located at other locations such as, for example, doors of the vehicle or a center console of the vehicle.

An embodiment of a vent assembly14is illustrated inFIG.3. The vent assembly14includes a bezel16, which defines a vent opening18through which the airflow20is directed into the occupant compartment3. The vent assembly14includes a movable primary vane22which is rotatable about a primary vane axis24, and a plurality of secondary vanes26, which are each rotatable about respective secondary vane axes28. In some embodiments, the primary vane axis24is a horizontal axis, such that rotation of the primary vane22about the primary vane axis24changes a direction of the airflow20in a first, vertical direction with respect to the passenger compartment3. Further, in some embodiments the secondary vane axis28is a vertical axis, such that rotation of the secondary vanes26about their secondary vane axes28changes the direction of the airflow20in a second, horizontal direction. The primary vane22and secondary vanes26are moved to direct the airflow20in a selected or desired direction. In some embodiments, the primary vane22and the secondary vanes26are movable via operation of one or more vent knobs which are rotated to effect movement of the primary vane22and the secondary vanes26. In other embodiments, other elements such as tabs connected to the primary vane22and the secondary vanes26are utilized to effect movement of the primary vane22and the secondary vanes26.

Referring now toFIG.4, the vent assembly14is operably connected to the HVAC system12along an airflow pathway between the HVAC system12and the vent assembly14. In some embodiments, the airflow pathway is a primary duct30, which directs the airflow20from the HVAC system12through the vent assembly14. In certain operating conditions, an effective cross-sectional area of the vent opening18restricts the airflow20from entering the occupant compartment3at a desired rate, such that airflow pressure in the primary duct30increases. A pressure relief valve32is located along the primary duct30, which automatically opens when a pressure of the airflow20in the primary duct30exceeds a threshold. Providing the pressure relief valve32allows for reduction in the cross-sectional area of the vent opening18, and mitigates the subsequent increase in internal system pressure that occurs under certain operating conditions by opening and thereby relieving the excess pressure and resistance in the system. For example, if the cross-sectional area of the vent opening18is reduced by 10% to 20%, the pressure relief valves32may be sized to provide that same 10% to 20% of cross-sectional area for airflow therethrough.

In some embodiments, such as shown inFIG.4and also inFIG.2, the pressure relief valve32is located at a top surface34of the instrument panel10. In some embodiments, such as illustrated inFIG.4, the pressure relief valve32is connected to the primary duct30via a secondary duct36. While in the embodiments illustrated and described herein, the pressure relief valve32is located at the top surface34of the instrument panel10, in other embodiments the pressure relief valve32may be positioned elsewhere, such as at a lower surface of the instrument panel10or at other locations in the vehicle1that may include HVAC airflow20, such as doors, floor, center consoles or the like. Further, the embodiment ofFIG.2includes three pressure relief valves32arrayed across the instrument panel10. One skilled in the art will readily appreciate that other numbers of pressure relief valves32, such as one, two, four, or five or more pressure relief valves32may be utilized. Additionally, in some embodiments the pressure relief valves32are located along the same primary duct30, while in other embodiments the HVAC system12includes multiple primary ducts30, and each primary duct30has a corresponding pressure relief valve32located along and connected to each primary duct30.

Referring now to the cross-sectional views ofFIGS.5A and5B, and the disassembled view ofFIG.6, the pressure relief valve32is installed to or thru a top pad38of the instrument panel10, which at one side defines the top surface34of the instrument panel10. The pressure relief valve32includes a housing40connected to the secondary duct36, which defines a flowpath for the airflow20through the pressure relief valve32. In some embodiments, the connection between the secondary duct36and the pressure relief valve32includes a foam ring42or other seal element located between the two components. The foam ring42acts to seal the interface between the housing40and the secondary duct36to prevent leakage of the airflow20at the interface. In some embodiments, the housing40is installed from the top surface34through a pad opening46in the top pad38toward the secondary duct36located at a back surface48of the top pad38. In some embodiments, the housing includes one or more of a housing lip52and a housing rib54extending radially outwardly from a valve axis58to retain the housing at the top pad38. In some embodiments, the top pad38is disposed between the housing lip52and the housing rib54at the pad opening46, such that the housing lip52is disposed at the top surface34and the housing rib54is disposed at the back surface48.

A diffuser56is installed into the housing40and is movable along the valve axis58, relative to the housing40. The diffuser56includes a tubular diffuser body60, which is open at a first end62and closed at a second end64defined by a diffuser cap66. The diffuser body60includes a plurality of body fingers86that extend along the valve axis58and terminate at the first end62. The body fingers86are flexible in a direction toward the valve axis58, and facilitate installation of the diffuser56into the housing40. In some embodiments, the diffuser cap66may be formed from a same material as the top pad38to improve the appearance of the pressure relief valve32in the instrument panel10. In some embodiments, such as illustrated inFIGS.5A and5B, the diffuser cap66is convex relative to the top pad38, while in other embodiments the diffuser cap66may be, for example, planar or concave. When the pressure relief valve32is in a closed position such as inFIG.5A, the diffuser cap66rests on the top surface34, and when the pressure relief valve32is in an opened position such as inFIG.5B, the diffuser cap66is moved along the valve axis58such that a cap gap68is defined between the diffuser cap66and the top surface34, allowing the airflow20to exit the diffuser56through one or more diffuser outlets70in the diffuser body60. In some embodiments, the diffuser outlets70have a hexagonal opening as illustrated, while one skilled in the art will readily appreciate that the shape, number, cross-sectional area, and position of the diffuser outlets70may be varied to achieve a desired degree of pressure relief by allowing a selected portion of the airflow to flow through the diffuser outlets70.

The pressure relief valve32is biased toward the closed position by a biasing element, which in some embodiments is a spring element72installed between a housing flange74and a diffuser flange76. In the embodiments shown, the diffuser flange76in formed in each of the body fingers86defined in the diffuser body60and extend radially outwardly from the body fingers86, relative to the valve axis58. In the illustrated embodiment, the spring element72is a coil spring, but one skilled in the art will readily appreciate that other spring element configurations may be utilized. Further, the spring elements72may be selected or tuned depending on the threshold pressure of the airflow20. When the pressure of the airflow20in the primary duct30exceeds the threshold, the biasing force of the spring element72is overcome and the diffuser56moves from the closed position to the opened position allowing the airflow20to exit the pressure relief valve32through the diffuser outlets70.

In other embodiments, such as inFIGS.7A and7B, the biasing element is a flexible biasing tab78extending curvilinearly outwardly outwardly from the diffuser body60and interactive with the housing flange74. When the pressure in the primary duct30exceeds the threshold, a biasing force of the biasing tab78is overcome, and the biasing tab78flexes, allowing the diffuser56to move along the valve axis58to the open position, as illustrated inFIG.7A. In another embodiment, illustrated inFIGS.8A and8B, the biasing element is a biasing ring80installed to the diffuser56. The biasing ring80includes a ring body82and one or more compressible protrusions84extending from the ring body82toward the back surface48of the top pad38, such that the protrusions84are between the ring body82and the back surface48, with the protrusions84biasing the diffuser56toward the closed position. When the pressure of the airflow20exceeds the threshold, the biasing force of the protrusions84is overcome and the diffuser56moves from the closed position to the opened position allowing the airflow20to exit the pressure relief valve32through the diffuser outlets70.

The configurations disclosed herein including the pressure relief valve32allow for reduction in the airflow resistance in the HVAC system12and further allow for introduction of increased airflow into the occupant compartment3for faster conditioning of the occupant compartment3in some operating conditions, such as those requiring full capacity of the HVAC system12. The configuration may also reduce air rush noises through the vent assembly14.