Abstract:
A valve for automatically and proportionally adjusting fluid flow between an engine and a radiator for cooling the fluid heated by the engine in response to changes in fluid temperature within a range of operating temperatures. The valve includes a housing having a chamber. The housing includes a radiator flow port for passing fluid between the radiator and the chamber. A vane pivotally disposed in the chamber has a vane wall engagable with the radiator port for restricting fluid flow. A drive assembly is operatively coupled to the vane for varying the position of the vane within the chamber.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims priority to and all the benefits of U.S. Provisional Application No. 60/396,431, filed on Jul. 15, 2002. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a valve for regulating flow of coolant fluid between a combustion engine and a radiator in an automotive vehicle. 
   2. Description of the Prior Art 
   Internal combustion engines for automotive vehicles generate heat from the combustion of fuel and friction between the many moving components within the engine, such as the between the engine block and the pistons. An engine-driven impeller propels coolant fluid between flow paths formed within the engine block and a heat sink or radiator exposed to ambient airflow passing over the surface of the radiator for carrying the heat away from the engine block Hoses are typically used to carry coolant fluid between the engine block and the radiator. 
   Typically, a wax valve or thermostat is coupled between the engine block and the radiator to control the flow of coolant fluid from the engine block to the radiator. Below a predetermined temperature, the thermostat is closed to restrict coolant fluid flow from the engine block to the radiator, which expedites warming of the engine. Above the predetermined temperature, a wax element within the thermostat expands proportionally in response to the rising coolant fluid temperature to mechanically engage and open a valve within the thermostat to allow coolant fluid to flow from the engine block to the radiator. In the radiator, the coolant fluid from the engine is cooled by heat exchange with ambient airflow passing over the surface of the radiator. The cooled coolant fluid passes from the radiator to the engine block and the coolant fluid is again heated by the combustion cycle and friction generated within the engine. The valve is spring biased closed so that within a range of temperatures around the predetermined temperature, the valve opening varies in size roughly in proportion to the coolant fluid temperature. However, wax thermostats are generally slow to respond to engine block temperature and are susceptible to failure due to clogging by contaminates commonly born within the coolant fluid due to corrosion within the engine block and radiator. 
   It remains desirable to provide a thermostat or valve that can be actively opened and closed to allow or restrict the flow of coolant fluid between the engine block and radiator in response to a wider range of engine variables and states over conventional wax thermostats. Further, it remains desirable to provide a valve that is resistant to the contaminants in the coolant fluid. 
   SUMMARY OF THE INVENTION 
   A valve proportionally controls the fluid flow between an engine and a radiator in an automotive vehicle. The valve includes a housing having a chamber coupled between the engine and the radiator. A radiator port extends between the radiator and the first end of the chamber for passing coolant between the radiator and the chamber. A bypass port extends between an outlet from the engine and the chamber for passing coolant flowing between the engine and the chamber. An engine port extends between an inlet from the engine and the chamber for passing coolant flowing from one or both of the radiator or bypass ports between the inlet of the engine and the chamber. A vane is disposed within the chamber and is pivotally coupled to the chamber for moving the arcuate plunger in and out of the arcuate neck for decreasing or increasing, respectively, fluid flow between the radiator and the engine through the housing, for adjusting a flow of fluid within the chamber. A drive assembly is operatively coupled with the vane for automatically varying the position of the vane within the chamber for proportionally controlling the amount of fluid flow between the radiator and the engine in response to changes in the temperature of the fluid within a predetermined operating temperature range. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     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: 
       FIG. 1  is an exploded view of a valve according to one embodiment of the invention; 
       FIG. 2  is a cut away perspective view of the valve in an open state; 
       FIG. 3  is a cut away perspective view of the valve in a closed state; 
       FIG. 4  is a perspective top view of the valve and a drive assembly for actuating the valve; and 
       FIG. 5  is a perspective bottom view of the valve and the drive assembly for actuating the valve. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIGS. 1-5 , a proportional valve  10  is shown for regulating the flow of coolant fluid between an engine (not shown) and a radiator (not shown) in an automotive vehicle. The valve  10  includes a molded housing  12 . The housing  12  includes a generally cylindrical vane support portion  14 . Opposing first and second chamber walls  16 ,  18  extend radially from the vane support portion  14 . A third chamber wall  20  spaced apart from the vane support portion  14  extends arcuately between the first and second chamber walls  16 ,  18 . An upper chamber wall  22  and a lower chamber wall  24  each extend between the first, second and third chamber walls  16 ,  18 ,  20  to define a generally wedge-shaped and substantially closed fluid chamber  26  therebetween. 
   An engine flow port  28  is formed in the third chamber wall  20  for passing fluid between the engine and the chamber  26 . A bypass flow port  30  is formed in the second chamber wall  18  for passing fluid between the engine and the chamber  26 . A radiator flow port  32  is formed in a portion of the first chamber wall  16  for passing fluid between the radiator and the chamber  26 . An arcuate neck  34  is formed in the radiator flow port  30  adjacent the first chamber wall  16 . 
   A vane  36  is pivotally carried by the vane support portion  14  for pivotal movement within the chamber  26  between the first and second chamber walls  16 ,  18  for controlling the flow of fluid between the chamber  26 , and any of the engine, bypass and radiator flow ports  28 ,  30 ,  32 . 
   In a preferred aspect of the invention, the vane  36  includes a cylindrical base  38  pivotally carried by the vane support portion  14 . A vane wall  40  extends radially outwardly from the base  38  between the base  38  and the third chamber wall  20 . The vane wall  40  pivotally swings between a first position in which the vane wall  40  engages the first chamber wall  16  and a second position in which the vane wall  40  engages the second chamber wall  18 . The vane wall  40  travels between the first and second positions in response to corresponding pivotal movement of the base  38  within the vane support portion  14 . 
   When in the first position, the vane wall  40  restricts fluid flow between the radiator flow port  32  and the chamber  26  and allows fluid flow between the engine  28  and bypass  30  flow ports. In a preferred embodiment, an annular slot  42  is formed in the first chamber wall  16  facing the chamber  26 . A ring shaped vane seal  44  is fixedly held within the annular slot  42  and protrudes axially from the first chamber wall  16  for elastically deforming against the vane wall  40  when the vane wall  40  is engaged with the first chamber wall  16 . The vane seal  44 , while deformed against the vane wall  40 , prevents fluid flow between the radiator flow port  32  and the chamber  26 . 
   A plunger  46  extends arcuately between the vane wall  40  and a distal end  48  for movement in and out of the neck  34  of the radiator flow port  30  as the vane wall  40  is pivoted in and out engagement with the first chamber wall  16 , respectively. The plunger  46  tapers from the vane wall  40  toward the distal end  48  in a configuration that mirrors the taper of the neck  34 . The taper of the neck  34  defines a profile such that the gap between the inner diameter of the neck  34  and the outer diameter of the plunger  46  remains constant along the entire length of the plunger  46  when the vane wall  40  is engaged with the first chamber wall  16 . The neck  34  and the plunger  46  are curved and frustoconical to accommodate the pivotal motion of the vane  36 . 
   When in the second position, the vane wall  40  restricts fluid flow between the chamber  26  and the bypass flow port  30  allowing fluid flow between the engine  28  and radiator  32  flow ports. 
   A drive assembly  50  is supported within a gear housing  51  fixedly secured to the housing  12  for moving and maintaining the vane  36  between the first and second positions. The drive assembly  50  includes an electric direct current motor  52  for driving a worm  54  and worm gear  56  arrangement. Rotational movement of the worm  54  by the motor  52  causes rotational movement of the worm gear  56 . In a preferred aspect of the present invention, the direct current motor  52  includes a shaft coupled to a pinion gear  70  which in turn rotates planetary gears  72  carried by a carrier  74  and ring  71  transferring rotational motion to the worm gear  56 . A clutch generally indicated at  57  is coupled between the worm gear  56  and the base  38  of the vane  36  for transferring rotational movement of the worm gear  56  to the vane  36 . The clutch also allows relative movement or slip between the worm gear  56  and vane  36  for relieving stress on the motor  52  when the vane  36  stops when engaging the first and second chamber walls  16 ,  18 . Preferably, the clutch  57  includes a clutch housing  58 , a shaft  60 , a friction disc  62 , and a spring disc  64 . The clutch housing  58  is secured to the base  38  of the vane  36 . The shaft  60  extends axially from the clutch housing  58  through a center bore in the worm gear  56 . The friction disc  62  and the spring disc  64  are axially compressed between the clutch housing  58  and the worm gear  56 . The friction disc  62  is keyed with the clutch housing  58  for pivotal movement therewith. The spring disc  64  axially forces the friction disc  62  toward the worm gear  56  so that pivotal movement of the worm gear  56  is transferred to the vane  36  by frictional torque created between the friction disc  62  and the worm gear  56 . The frictional torque created by the axial compression of the spring disc  64  is predetermined and is generally less than the amount of torque associated with occasional sudden engagement of the vane  36  with the first or second chamber walls  18 ,  20 . 
   The drive assembly  50  is controlled by a central processor (not shown) in response to temperature or pressure sensors located within the engine. In a preferred aspect of the present invention, a Reed type switch  66  is coupled to the worm  54  for providing positional feedback to the central processor of the vane  36  based on the rotation and position of the worm  54 . An encoder  76  may be coupled to the worm  54  by an appropriate bushing  75  to be read by the Reed switch  66  to determine the position of the worm  54 . The drive assembly  50  can be sealed from the fluid within the chamber  26  by an O-ring seal  77 , as best seen in FIG.  1 . 
   In operation, fluid is propelled through the engine block by an impeller driven by the engine. Until the engine reaches a predetermined operating temperature, the central control processor maintains the vane  36  in its first position engaging the first chamber wall  16 . In the first position, the vane wall  40  is seated against the vane seal  44  for preventing fluid flow between the radiator flow port  32  and the chamber  26 . As a result, back pressure is created in the radiator, which shunts fluid flow through the radiator and prevents heat transfer from fluid to the ambient air passing over the radiator. The fluid, driven by the impeller, takes the lower pressure path through the bypass flow port  30 . Fluid passes freely between the bypass flow port  30  and the engine flow port  28  through the chamber  26 . Continued operation of the engine causes the fluid temperature to rise. Once the fluid reaches the predetermined operating temperature, the central control processor commands the drive assembly  50  to pivot the vane wall  40  away from the vane seal  44  and first chamber wall  16  to allow fluid flow between the radiator flow port  32  and the engine flow port  28  through the chamber  26 . Fluid flow between the radiator flow port  32  and the chamber  26  relieves back pressure in the radiator, allowing fluid to flow from the engine and through the radiator. Heat energy is transferred from the fluid through the radiator to the ambient air passing over the radiator, lowering the temperature of the fluid. 
   Movement of the vane wall  40  toward and away from the first chamber wall  16  causes the plunger  46  to move in and out of the neck  34  of the radiator flow port  32 . Movement of the plunger  46  in and out of the neck  34  of the radiator flow port  32  decreases and increases, respectively, the fluid flow between the radiator flow port  32  and the chamber  26 . The vane wall  40  may be moved and held in any position by the drive assembly  50  between the first and second chamber walls  16 ,  18  to vary the amount of fluid flow between the bypass and engine flow ports  30 ,  28  and the radiator and engine flow ports  32 ,  28 . In general, the fluid flow between the bypass and engine flow ports  30 ,  28  varies inversely and in proportion with the fluid flow between the radiator and engine flow ports  32 ,  28 . 
   The invention has been described in an illustrative manner, and it is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation. 
   Many modification and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced other than as specifically described.