Patent Application
20090229785
1. Field of the Invention
The present invention relates to thermally conditioning a seat in an automotive vehicle using an HVAC system of the vehicle.
2. Description of the Prior Art
The thermal comfort of occupants in a vehicle is traditionally provided by the central heating, ventilation and air conditioning (HVAC) assembly of the vehicle controlled by the vehicle occupant. The occupant selects a predetermined air temperature indicating a desired air temperature at which to be thermally conditioned. In response, traditional HVAC assemblies operate in either a warm-up mode and/or a cool-down mode to generate heated and/or cooled air having a temperature approximately equal to the predetermined air temperature. The warmed and/or cooled air can be exhausted into the vehicle cabin, under the seat, and/or behind the seat via one or more air ducts. As a result, the occupant is heated and/or cooled by convection through the surrounding medium in the interior of the vehicle. More recently, vehicle seating assemblies have been disclosed that provide for heating and cooling of the occupant by an independent thermoelectrically energized unit incorporated into a vehicle seat. These units typically consist of one or more thermoelectric modules, heat exchangers and fans that are operated by allowing the fan to blow air over the sides of the seat, resulting in the seat being thermally conditioned. Further, the warmed and/or cooled air can be directed through or over the seat to the occupant's body surface via seat outlets disposed in the seat assembly. At startup, the air delivered by these thermoelectrically climate controlled seats is initially cold when the HVAC assembly operates in the warm-up. Similarly, the air is initially warm when the HVAC assembly operates in the cool-down mode. As a result, a natural transient thermal response exists that effects the air exhausted from the seat outlets of the seat assembly.
The cooling and heating of a occupant in an automotive vehicle can most effectively be obtained by applying the thermal condition directly to the human being. The current automotive air conditioning systems utilize ducts, such as cabin ducts and seat ducts, which lead to vents for delivering warm and/or cool air to the vehicle cabin and seat assembly. The effectiveness in cooling and/or heating occupants in an automobile is significantly decreased due to the thermal transfer from the air generated by the HVAC assembly to the surrounding air. Therefore, only part of the temperature exchange is directed toward to the vehicle occupant.
The optimum effect is attained by applying the conditioned air as directly as possible to the vehicle occupant. This is accomplished by delivering conditioned air to the occupant seat from a known source like the HVAC assembly or a thermoelectric cooler/heater disposed within the seat, as illustrated in U.S. Pat. No. Re. 38,128 to Gallup et al., U.S. Pat. No. 5,924,766 to Esaki et al., and U.S. Pat. No. 6,079,485 to Esaki et al., and PCT application WO 99/58907 to Bell.
The air from the HVAC assembly on initial startup is not thermally conditioned. In the case of heating, it takes time to warm the coolant due to the thermal inertia of the engine. In the case of cooling, it takes time the traditional A/C cycle to cool air. When initiating the warm-up mode, the occupant is typically not satisfied with the warming effect immediately generated at start-up. Similarly, when initiating the cool-down mode, the occupant is typically not satisfied with the immediate cooling effect. The adverse effect caused by the natural temperature transient that exists at start-up may be resolved by providing an auxiliary air-conditioning device in the ductwork between the HVAC module and the seat passages of the seat assembly for exchanging preconditioned air generated by the HVAC assembly to achieve a faster warming and/or cooling effect desired by the occupant, as disclosed in U.S. Pat. No. 7,238,101 to Kadle et al. Although an auxiliary air-conditioning device can increase the warming and/or cooling effect desired by the occupant, the additional air-conditioning device increases vehicle cost. Further, the additional air-conditioning device increases power consumption, thereby decreasing the overall energy efficiency of the vehicle.
In addition to the structure described above, this invention provides for a control system for opening a purge valve and closing one or more seat valves in response to the air temperature from the HVAC assembly being less than a predetermined temperature. Furthermore, the control system closes the purge valve and opens at least one seat valve to deliver air from the air selection module to the seat assembly in response to the air temperature being at least the predetermined air temperature. Accordingly, the occupant is exposed to air having at least the predetermined air temperature desired.
The invention provided leverages the traditionally HVAC assembly to increase the warming and/or cooling effect desired by the vehicle occupant, thereby decreasing vehicle costs while increasing energy efficiency.
Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
Referring to the Figures, wherein like numerals indicate corresponding parts throughout the several views, an automotive vehicle 20 is generally shown including a body 22 defining a occupant cabin 24. A seat assembly 26 is generally indicated and is disposed in the occupant cabin 24. The seat assembly 26 includes a seat bottom 28 and a seat back 30 for holding an occupant therein. The seat bottom 28 and the seat back 30 have a plurality of seat outlets 32 for exhausting air to the occupant seated in the seat assembly 26. The seat bottom 28 includes a seat bottom inlet 34 and the seat back 30 includes a seat back inlet 36. The seat bottom inlet 34 receives air and delivers the air into the seat bottom 28. The air within the seat bottom 28 is expelled through the seat outlets 32 such that air can be delivered to the lower half of the occupant. Similarly, the seat back inlet 36 receives air and delivers air into seat back 30 such that air is expelled through the seat outlets 32 such that air is exhausted to the upper half of the occupant.
The automotive vehicle 20 includes a temperature selector 29, an HVAC assembly 38 supported by the body 22 of the automotive vehicle 20 for generating thermally conditioned air, and an air temperature sensor 40. The temperature selector 29 is operable by the occupant for selecting a predetermined air temperature (TPRE). The predetermined air temperature (TPRE)is indicative of the air temperature (TAIR) the occupant desires to be exhausted from the seat assembly 26. In response to selecting the predetermined air temperature (TPRE), a predetermined air temperature (TPRE) signal is output by the temperature selector indicating the predetermined air temperature (TPRE).
The HVAC assembly 38 is initiated to generate air in response to either a warm-up signal or a cool-down signal. In addition to selecting the predetermined air temperature (TPRE) the temperature selector 29 can be used to select the warm-up mode and the cool-down mode. An occupant selects the warm-up mode with a desire to receive heated air from the seat assembly 26. Similarly, the occupant selects the cool-down mode with a desire to receive cooled air from the seat assembly 26. The purpose of HVAC assembly 38 while operating in either mode is to generate air that will attain the predetermined air temperature (TPRE) selected by the occupant.
The air temperature sensor 40 is disposed downstream from the HVAC assembly 38 and within the HVAC duct 42 for sensing the temperature of the air generated by the HVAC assembly 38. Although
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Seat valves 52, 54 are integrated with both the seat bottom duct 46 and the seat back duct 48 and operate in response to one or more control signals. The seat valves 52, 54 operate in an open position for allowing airflow to the seat ducts 42, 46, 48, 50 and in a closed position for blocking airflow to the seat ducts 42, 46, 48, 50. Specifically, a seat bottom valve 52 is disposed between the seat bottom duct 46 and the air selection module 44 for opening in response to a seat bottom open signal (SEATBOTTOMOPEN) and for closing in response to a seat bottom close signal (SEATBOTTOMCLOSE) to regulate the delivery of air to the seat bottom duct 46. A seat back valve 54 is disposed between the seat back duct 48 and the air selection module 44 for opening in response to a seat back open signal (SEATBACKOPEN) and for closing in response to a seat back close signal (SEATBACKCLOSE) to regulate the delivery of air to the seat back duct 48.
The air selection module 44 includes a purge duct 50 having a purge valve 56 for controlling airflow therethrough. The purge duct 50 extends along the body 22 and beneath the seat assembly 26 for exhausting air from the air selection module 44 and for diverting air away from the seat ducts. The purge valve 56 is disposed between the purge duct 50 and the air selection module 44 and moves between an open position and a closed position in response to one or more control signals. Specifically, the purge valve 56 opens in response to a purge open signal (PURGEOPEN) for venting air from the air selection module 44 and a closed position in response to the purge close signal (PURGECLOSE) for blocking airflow through the purge duct 50.
When the occupant desires air to be delivered from the seat assembly 26, the occupant selects the operating mode of the HVAC assembly 38 and the corresponding predetermined temperature. The HVAC assembly 38 is initiated and generates air in response to either the warm-up signal or the cool-down signal. The air is delivered to the air selection module 44 via the HVAC duct 42. Once delivered to the air selection module 44, airflow is either blocked from entering the seat assembly 26 and vented from the air selection module 44 or is delivered to the seat assembly 26 where it is exhausted from the seat outlets 32. When both the seat bottom valve 52 and the seat back valve 54 are closed while the purge valve 56 is opened, airflow to the seat bottom duct 46 and seat back 30 is blocked and air is vented from the air selection module 44. Accordingly, air is blocked from being delivered to the seat assembly 26 and is prevented from being exhausted to the occupant. However, when both the seat bottom valve 52 and the seat back valve 54 are open while the purge valve 56 is closed, air is delivered to the seat bottom 28 and seat back 30 via the seat bottom duct 46 and the seat back duct 48, thereby allowing air to be exhausted from the seat outlets 32 to thermally condition the occupant.
The automotive vehicle 20 further includes a heat element assembly for emitting heat to warm the seat assembly 26 and the occupant seated therein. The heat element assembly is disposed in the seat assembly 26 for heating the seat assembly 26 in response to an energizing signal (HEATON). The heat element assembly includes a power supply 58 and a plurality of heating elements 60 connected to the power supply 58 and disposed with each of the seat bottom 28 and seat back 30. The energizing signal (HEATON) switches on the power supply 58 for generating current to the heating elements 60. In response to the current, the heating elements 60 emit heat that warms the seat bottom 28 and seat back 30. A seat temperature sensor 64 is disposed within the seat assembly 26 for sensing a seat temperature (TSEAT) of the seat assembly 26 and for outputting a seat temperature (TSEAT) signal in response to sensing the seat temperature (TSEAT).
The automotive vehicle 20 is distinguished by a control system 62 for opening and closing the purge valve 56, the seat bottom valve 52, and the seat back valve 54 in response to a comparison between the temperature of the air generated by the HVAC assembly 38 and the predetermined air temperature (TPRE) selected by the occupant. The control system 62 includes a HVAC controller 66 in signal communication with the air temperature TAIR selector 29, the HVAC assembly 38 and the air selection module 44. The HVAC controller 66 receives the predetermined air temperature (TPRE) from the air temperature (TAIR) selector and outputs either the warm-up signal or the cool-down signal that initiates the HVAC assembly 38 for generating air to achieve the predetermined air temperature (TPRE).
The HVAC controller 66 receives the air temperature (TAIR) signal from the air temperature sensor 40 indicating the air temperature (TAIR) of the air generated by the HVAC assembly 38. The HVAC controller 66 compares the air temperature (TAIR) to the predetermined air temperature (TPRE)and outputs one or more control signals to the air selection module 44 to open and/or close the purge valve 56, the seat bottom valve 52 and the seat back valve 54. As stated earlier, the position of the valves 52, 54 regulates the airflow delivered to the purge duct 50, the seat bottom duct 46 and the seat back duct 48 to ensure the air delivered from the seat outlets 32 at the predetermined air temperature (TPRE) selected by the occupant, as discussed further below.
The HVAC controller 66 outputs a purge open signal (PURGEOPEN), a seat bottom close signal (SEATBOTTOMCLOSE) and a seat back close signal (SEATBACKCLOSE) in response to the air temperature (TAIR) generated by the HVAC assembly 38 being less than the predetermined air temperature (TPRE) selected by the occupant. The purge open signal (PURGEOPEN) opens the purge valve 56 to vent air from the air selection module 44. The seat bottom close signal (SEATBOTTOMCLOSE) and the seat back close signal (SEATBACKCLOSE) close the seat bottom valve 52 and the seat back valve 54, respectively, to block airflow to the seat bottom duct 46 and seat back duct 48. Similarly, the control module outputs a purge close signal (PURGECLOSE), a seat bottom open signal (SEATBOTTOMOPEN) and a seat back open signal (SEATBACKOPEN) in response to the air temperature (TAIR) being at least the predetermined air temperature (TPRE). The purge close signal (PURGECLOSE) closes the purge valve 56 to block airflow through the purge duct 50. The seat bottom open signal (SEATBOTTOMOPEN) and the seat back open signal (SEATBACKOPEN) open the seat bottom 28 vent and the seat back 30 vent, respectively, to deliver air from the air selection module 44 to the seat bottom duct 46 and seat back duct 48. As a result, the occupant is exposed to air from the seat outlets 32 only when the air temperature (TAIR) from the HVAC assembly 38 is at least the predetermined air temperature (TPRE) selected by the occupant.
The HVAC controller 66 is also in signal communication with the heated seat assembly 26 and the seat temperature sensor 64 to warm the occupant when the HVAC assembly 38 operates in the warm-up mode and while the airflow through the air selection module 44 attains at least the predetermined air temperature (TPRE). The HVAC controller 66 outputs an energizing signal (HEATON) to switch on the power supply 58 in response to the occupant selecting the warm-up mode. The HVAC controller 66 outputs a de-energizing signal (HEATOFF) to switch off the power supply 58 in response to the air temperature (TAIR) being at least the predetermined air temperature (TPRE) and/or the seat temperature (TSEAT) being at least a predetermined seat temperature (TSEAT). The HVAC controller 66 can also de-energize the heated seat assembly 26 when the occupant selects the HVAC assembly 38 to operate in the cool-down mode. Accordingly, the control system 62 leverages the traditionally HVAC assembly 38 to increase the warming and/or cooling effect desired by the vehicle occupant, thereby decreasing vehicle costs while increasing energy efficiency.
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While the invention has been described with reference to an exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
