Abstract:
A fluid-based or fluidic climate control system for a seat includes first and second portions positionable adjacent to first and second surfaces of the seat and a fluid control module (FCM) for circulating fluid in a closed-loop within the portions. The FCM delivers fluid to the portions at independently-controllable temperatures. An interface may be used to control the temperatures. The FCM may include a heat exchanger module (HEM) having a fan connected to an energy storage device (ESD). The FCM may include a miniature vapor compressor for circulating the fluid. A method of cooling a seat includes positioning first and second portions of the system adjacent to different surfaces of the seat, and using the FCM to circulate fluid within a closed-loop passage of the portions while independently controlling the temperature of the fluid, and thus the portions, using a user interface.

Description:
TECHNICAL FIELD 
     The present invention relates generally to vehicle climate control systems, and more specifically to a portable climate control system for selectively heating and/or cooling different surfaces of a seat. 
     BACKGROUND OF THE INVENTION 
     In a vehicle climate control system, heating and air conditioning systems may be used to respectively direct warm and cold air into a passenger compartment of the vehicle. Control devices in some vehicles allow different passengers to select a desired temperature setting for the air that is discharged from a vent located in their particular section of the passenger compartment. Other vehicles may be equipped with seat warming devices which pass a warming electrical current through conductive coils embedded within the vehicle seat. For cooling, air ducts may be routed through the seat base to discharge cool air through the surfaces of the vehicle seat. 
     Thermoelectric systems transfer heat by applying a DC voltage to sides of a semiconductor to create a temperature differential. A corresponding transfer of heat occurs between the sides, which may be constructed of different materials to enhance the heat transfer effect. Thermoelectric systems have certain size and weight advantages as they do not require use of a heat transfer fluid within a conventional evaporating/condensing unit. However, the potential advantages of thermoelectric devices when used in conjunction with a vehicle climate control system may be offset by their relative energy inefficiency and durability. 
     SUMMARY OF THE INVENTION 
     Accordingly, a self-contained or a closed-loop climate control system is provided for use with a seat, such as but not limited to a vehicle seat. The system is portable, i.e., it is not permanently integrated with the structure of the seat itself, and therefore when used with a vehicle seat it may be used as an aftermarket device within more than one vehicle in order to provide a relatively energy efficient alternative to a thermoelectric-based system as described above. The system has separate seat and back portions each containing an internal network of flexible tubing. 
     A fluid control module (FCM) is connected to the seat and back portions and may be draped in front of a vehicle seat cushion or stowed underneath such a cushion. The FCM contains a miniature vapor compressor, a heat exchanger module (HEM) having condensing and evaporating capabilities, and a set of control valves each automatically operated in response to temperature commands transmitted from a compact user interface. Actuation of the valves directs the fluid as needed to achieve a desired seat temperature. 
     The miniature compressor circulates a suitable fluid, e.g., a refrigerant such as R134a or other suitable coolant, in a closed-loop fluid circuit in the seat and back portions. When positioned adjacent to different surfaces or cushions of a vehicle seat, the back portion may be immediately adjacent to the back cushion and the seat portion may be immediately adjacent to the seat cushion. Selective heating and cooling of the back and seat portions is provided using the user interface, which allows heating or cooling of the back and seat portions together, cooling of the seat portion with heating of the back portion, or cooling of the back portion with heating of the seat portion. The system may be powered by the vehicle&#39;s auxiliary power system in one embodiment, or may be provided with its own power supply in another embodiment. 
     In particular, a climate control system for use with a seat includes a first portion that may be positioned adjacent to a first surface of the seat, a second portion that may be positioned adjacent to a second surface of the seat, and an FCM operable for circulating a supply of fluid within a closed-loop fluid passage within the first and second portions. The FCM delivers the fluid to the first portion at a first temperature and to the second portion at a second temperature, with the first and second temperatures being independently controllable. The user interface may be used to control the temperatures, and may include a pair of temperature input devices, e.g., knobs or buttons, each adapted for controlling a temperature of a corresponding one of the back and seat portions. The FCM may include a heat exchanger module (HEM) having an electric fan that is electrically connected to an energy storage device (ESD) and cooled thereby, e.g., an auxiliary vehicle power supply or a separate battery pack. The FCM may include a miniature vapor compressor for compressing the fluid and for circulating the fluid through the closed-loop fluid passage. 
     A method of cooling a seat includes positioning a first portion of a climate control system adjacent to a first surface of the seat, positioning a second portion of the climate control system adjacent to a second surface of the seat, using the FCM to circulate fluid within a closed-loop fluid passage of the first and second portions, and independently controlling the temperature of the fluid in the different portions using the user interface. 
     The above features and advantages and other features and advantages of the present invention will be readily apparent from the following detailed description of the preferred embodiments and best modes for carrying out the present invention when taken in connection with the accompanying drawings and appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view illustration of a vehicle having a seat that is usable with a portable climate control system (CCS) in accordance with the invention; 
         FIG. 2  is a schematic front view illustration of the portable CCS usable within the vehicle of  FIG. 1 ; 
         FIG. 3  is a schematic side view illustration of the portable CCS of  FIG. 2 ; 
         FIG. 4A  is a schematic fluid circuit diagram describing fluid flow for a first climate configuration for the portable CCS of  FIGS. 2 and 3 ; 
         FIG. 4B  is a schematic fluid circuit diagram describing fluid flow for a second climate configuration for the portable CCS of  FIGS. 2 and 3 ; 
         FIG. 4C  is a schematic fluid circuit diagram describing fluid flow for a third climate configuration for the portable CCS of  FIGS. 2 and 3 ; and 
         FIG. 4D  is a schematic fluid circuit diagram describing fluid flow for a fourth climate configuration for the portable CCS of  FIGS. 2 and 3 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings wherein like reference numbers refer to like components throughout the several views, and beginning with  FIG. 1 , a vehicle  10  includes a body  12  defining a passenger compartment  14 . While the body  12  is configured as a sedan in the embodiment shown in  FIG. 1 , the body may also be configured as a pickup truck, a sport utility vehicle, a crossover vehicle, or any other vehicle body defining a passenger compartment  14 . The vehicle  10  includes an energy storage device (ESD)  18  such as a 12-volt onboard auxiliary battery suitable for powering one or more vehicle accessories aboard the vehicle  10 , or a power pack separate from the auxiliary battery as described below. 
     Within the scope of the invention, the seat  16  may be equipped with a portable climate control system  20 . The system  20  may be electrically connected to the ESD  18  using wires  19  or a wiring harness to provide the electrical current needed for powering the various fluid control devices within the system  20  as set forth below. The ESD  18  may be an under-seat power pack that is separate from the vehicle&#39;s auxiliary power system according to one embodiment, the 12-volt auxiliary battery noted above, or another battery pack or suitable energy source. 
     The surfaces of the seat  16  may be hot or cold to the touch, with the temperature changing with the particular season. System  20  therefore provides a portable climate control device that is capable of covering the seat  16 , thus allowing a user to transport the system  20  between different vehicles, or to move the system  20  between different seats  16  within the same vehicle. The system  20  may be provided as optional equipment for vehicle  10 , or may be provided on an aftermarket basis for use in vehicle  10  or any other vehicle having a seat  16 . Those of ordinary skill in the art will recognize that although vehicular applications are well suited for use with the system  20 , the system  20  is not limited to vehicular applications, and may be used in conjunction with other seats, e.g., lawn chairs, theater seats, stadium seats, etc., without departing from the intended scope of the invention. 
     Referring to  FIG. 2 , in one embodiment the system  20  includes a back portion  22 , a seat portion  24 , connecting portions  25 , and a fluid control module (FCM)  26 . The back portion  22  and the seat portion  24  may be placed over or positioned adjacent to a back cushion  16 B and seat cushion  16 A of the seat  16  as shown in  FIG. 3 . The system  20  may also be embodied as a single cushion without departing from the intended scope of the invention. The system  20  may be removably connected to the seat  16  to allow portability of the system between different seats  16 , whether the seats are vehicle seats or other non-vehicular seats. The FCM  26  may be electrically connected to the ESD  18  via the wires  19 , and operation of the FCM  26  may be selectively controlled by a user through an interface  30  as described below. 
     The FCM  26  includes a vapor compressor (COMP)  42 , a heat exchanger module (HEM)  44 , and a set of control valves (V)  46 . The HEM  44  is capable of acting as an evaporator or a condenser as needed, and includes a small electric fan  52  for facilitating heat transfer within the HEM  44 . As shown in  FIGS. 4A-D , the valves  46  may include a 4-way master control valve  67 , a thermal expansion valve  65 , and a plurality of on/off valves  60 ,  62 ,  64 ,  66 , and  68 , with the valves  46  selectively controlled as described below with reference to  FIGS. 4A-D  to provide a desired heating/cooling experience. 
     Still referring to  FIG. 2 , the system  20  includes coils  28 A,  28 B in the seat portion  24  and back portion  22 , respectively, with the coils  28 A,  28 B defining an internal fluid passage  33 . The fluid passage  33  forms a closed-loop or self-contained fluid circuit between the FCM  26  and the respective back and seat portions  22 ,  24 . Using the compressor  42 , fluid  17  such as R134a or another suitable coolant or refrigerant, is moved in liquid and/or gaseous states through the passage  33 , with the state of the fluid  17  being dependent on the particular heating/cooling cycle. That is, when operating as a condenser the HEM  44  receives fluid  17  from the compressor  42  and allows heat to dissipate, whereupon the fluid  17  expands via the thermal expansion valve  65  (see  FIGS. 4A-D ). The temperature of the fluid  17  is rapidly decreased. The cold fluid, which is now at a low-pressure, is evaporated by the HEM  44  to change to a gaseous state. The gaseous fluid  17  may then be compressed by the compressor  42 , and the cycle repeats. 
     A desired seat temperature may be selectively varied using the interface  30 . For example, in one embodiment the interface  30  may include an on/off switch or button  32  and temperature input devices  34  and  36  each dedicated to controlling the temperature of a respective one of the back and seat portions  22  and  24 . The interface  30  may connect to the FCM  26  through a connection  21 , which may be a hardwired connection or a remote/wireless link depending on the desired design. When hardwired, the length of connection  21  may be relatively short to ensure that the interface  30  remains in close proximity to the FCM  26 , or may be long so as to place the interface a distance away from the FCM  26  at a conveniently accessible position within the passenger compartment, e.g., on an instrument panel or a shift lever. A remote/wireless link likewise would allow the interface  30  to be positioned anywhere within the passenger compartment  14  of  FIG. 1 . 
     Referring to  FIG. 3 , the HEM  44  of FCM  26  requires a free flow of air to provide the required heat transfer, with the airflow represented in  FIG. 3  by arrows A. Such airflow may be enabled by draping the FCM  26  with respect to the seat portion  24  of  FIG. 3 , with air flowing into a space beneath the seat  16 . The FCM  26  is thus adapted for stowage adjacent to a base  16 C of the seat  16 . Fluid  17  is allowed to flow within the coils  28 A,  28 B as indicated by arrows B, flowing through the seat portion  24  and the back portion  22  before returning to the FCM  26  for recirculation. A self-contained or closed-loop fluid circuit is thus formed. In one embodiment, the coils  28 A,  28 B may be constructed of a flexible and resilient material to ensure the physical integrity and long term durability of the coils  28 A,  28 B in the presence of a compressive force, i.e., a user sitting on the system  20  during its use with the seat  16  of  FIG. 1 . 
     Referring to  FIG. 4A , the system  20  may be controlled to provide a first climate configuration wherein both the back portion  22  and the seat portion  24  are heated. A user may utilize the interface  30  of  FIGS. 2 and 3  to select such an option, such as by turning the on/off switch  32  to an “on” position and turning each of the devices  34 ,  36  to a desired temperature. In response to these commands the valves  60 ,  62 , and  64  are closed and valves  66  and  68  are opened. For simplicity, valves  60 ,  62 ,  64 ,  66 , and  68  are represented as schematic open/closed switches, and may be embodied by any dual-state fluid control device. 
     The compressor  42  delivers fluid  17  at an increased temperature under pressure to the 4-way control valve  67 . The valve  67  actuates to deliver the fluid  17  to the coils  28 A,  28 B. The heated fluid  17  is directed through the passage  33  of coils  28 A,  28 B. After passing through the back portion  22 , the fluid  17  is directed through the valve  62 . The fluid  17  then passes through thermal expansion valve  65  and the valve  60 , rapidly dropping the pressure and temperature of the fluid  17 . The now cold and primarily gaseous fluid  17  is directed to the HEM  44 , wherein an evaporating processes occurs before returning the fluid  17  to the compressor  42  through the valve  67 . The cycle repeats until the user selects a different setting using the interface  30 . 
     Referring to  FIG. 4B , the system  30  may be controlled to provide a second climate configuration wherein the back portion  22  and the seat portion  24  are cooled. A user may utilize the interface  30  of  FIGS. 2 and 3  to select such an option, and in response the valves  60 ,  62 , and  64  are closed while the valves  66  and  68  are opened. The compressor  42  delivers fluid  17  under pressure to the 4-way control valve  67  as before. However, in this embodiment the heated and high-pressure fluid  17  is directed to the HEM  44  for condensing before passing through valve  60  and into thermal expansion valve  67 . Cool fluid  17  then passes through the coils  28 A of the seat portion  24  and through the valve  62  to the coils  28 B of the back portion  22 , thereby cooling the back portion  22  and seat portion  24 . After passing through the seat portion  24  and back portion  22 , the fluid  17  returns to the 4-way valve  67  and is circulated in a closed-loop until the user selects a different setting using the interface  30 . 
     Referring to  FIG. 4C , the system  30  may be controlled to provide a third climate configuration wherein the seat portion  24  is cooled and the back portion  22  is heated. A user may utilize the interface  30  of  FIGS. 2 and 3  to select such an option, and in response valves  60 ,  62 , and  64  are opened, while valves  66  and  68  are closed. Fluid  17  from the compressor  42  enters the 4-way valve  67  and is directed into the coils  28 B of the back portion  22 , thus heating the back portion. Thereafter, the warm fluid  17  passes through valve  68  and to the thermal expansion valve  65 . The open valve  60  directs all fluid flow into the valve  65 . Upon expansion, the cold fluid  17  passes through coils  28 A of the seat portion  24 , thereby cooling the seat portion  24 . The fluid  17  returns to the compressor  42  via the 4-way valve  67  and the cycle repeats in a closed-loop until the user selects a different setting using the interface  30 . 
     Referring to  FIG. 4D , the system  30  may be controlled to provide a fourth climate configuration wherein the seat portion  24  is heated and the back portion  22  is cooled. A user may utilize the interface  30  of  FIGS. 2 and 3  to select such an option, and in response valves  60 ,  62 , and  64  remain open and valves  66  and  68  remain closed. Warm fluid  17  that is discharged from the compressor  42  enters the 4-way valve  67 , which is actuated to direct the fluid  17  to the coils  28 A of the seat portion  24 , thereby heating the seat portion  24 . Thereafter, the heated fluid  17  passes through the thermal expansion valve  65  and undergoes expansion and cooling. The open valve  60  ensures that all of the fluid  17  is directed into the coils  28 B of the back portion  22  through the valve  68 , thereby cooling the back portion  22 . Fluid  17  then returns to the compressor  42  though the valve  67  and the cycle repeats in closed-loop until the user selects a different setting using the interface  30 . 
     While the best modes for carrying out the present invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.