Patent Publication Number: US-7721973-B2

Title: Valve

Description:
FIELD OF THE INVENTION 
   The present invention generally relates to a valve for controlling the flow of fluid. 
   BACKGROUND OF THE INVENTION 
   In automobile engines, a fluid or coolant is typically used to carry excess heat from the engine to the radiator. Usually, such coolant is continuously circulated, by an engine-driven pump, through the engine until its temperature exceeds a predetermined level, at which point a portion of the flow is routed through the radiator. The flow is continuously adjusted in an attempt to maintain the temperature of the coolant within a desired range. Often, this is done via a valve that is actuated by a wax motor that is immersed in the flow. 
   In a known prior art fluid circuit, the radiator and a closure valve are connected in series in the coolant circuit, and a bypass circuit is connected in parallel across the radiator and closure valve. The valve is configured so as to block the flow of coolant through the radiator when the valve is closed. When the valve is closed, the coolant continues to circulate through the engine via the bypass circuit. A disadvantage associated with this configuration is that the bypass flow path remains open at all times such that a substantial portion of the flow of coolant always bypasses the radiator, even if maximum cooling is called for. 
   Various valves form part of the prior art. 
   To avoid the problems associated with a permanent bypass flow, these valves provide for the selection between a heat exchanging fluid circuit, which passes through the radiator, or a non-heat exchanging fluid circuit, which short circuits or bypasses the radiator. However, known valves are either relatively expensive, relatively non-robust, or have relatively poor flow characteristics. 
   SUMMARY OF THE INVENTION 
   A valve for use with a fluid forms one aspect of the invention. This valve comprises a valve body and a plug. The valve body has: a pair of spaced-apart flow ports; an interior chamber; an interior wall at least partially dividing the interior chamber into a first subchamber to which one of the flow port leads and a second subchamber to which the other of the flow ports leads, the interior wall having a wall opening therethrough leading between the first subchamber and the second subchamber; an interior opening providing for communication between the first subchamber and the second subchamber; and a further flow port spaced-apart from the interior opening along an axis. The plug has a plug opening therein, and is axially moveable in the interior chamber between and a first position and a second position. At the second position, the plug seals the further flow port and the valve defines a first flow path between the spaced-apart flow ports, through the wall opening; and a second flow path between the spaced-apart flow ports, through the interior opening and the plug opening. At the first position, the interior wall seals the plug opening and the plug seals the interior opening and the wall opening, thereby to at least substantially isolate the first subchamber from the second subchamber and channel the flow through a further flow path for said fluid through the valve body between the other of the flow ports and the further flow port. 
   According to another aspect of the invention, the first flow path and the second flow path can collectively define a primary flow path, and the primary flow path and the further flow path can each be free of substantial constrictions over their respective lengths. 
   A valve for use with a fluid forms yet another aspect of the invention. This valve comprises a valve body and a plug. The valve body has a pair of spaced-apart flow ports and includes a tubular structure. The tubular structure has a side wall and an open end and defines interiorly a first subchamber in fluid communication with one of the flow ports. The wall has a wall opening therethrough. The body further defines a second subchamber in fluid communication with the other of the flow ports, the second subchamber extending around the side wall and extending beyond the open end to further fluidly communicate with the open end and the wall opening. The plug has a plug opening and is mounted to the tubular structure for telescopic movement between a first position and a second position. At the second position, the plug is disposed at least in part in the second subchamber and the valve defines: a first flow path between the flow ports through the wall opening; and a second flow path between the flow ports through the open end of the tubular structure and the plug opening. At the first position, the plug and tubular structure interact to restrict flow through the first flow path and the second flow path. 
   The present invention permits the construction of a relatively low cost, relatively robust valve, which exhibits relatively good flow characteristics. Other advantages, features and characteristics of the present invention, as well as methods of operation and functions of the related elements of the structure, and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following detailed description and the appended claims with reference to the accompanying drawings, the latter being briefly described hereinafter. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a valve according to one embodiment of the invention; 
       FIG. 2  is an exploded perspective view of the structure of  FIG. 1 ; 
       FIG. 3  is a view of encircled area  3  of  FIG. 2 ; 
       FIG. 4  is a top view of the structure of  FIG. 3 ; 
       FIG. 5  is a section along  5 - 5  of  FIG. 4 , 
       FIG. 6  is an enlarged view of encircled area  6  of  FIG. 2 ; 
       FIG. 7  is a perspective view of the structure of  FIG. 6 , from another vantage point; 
       FIG. 8  is a side view of the structure of  FIG. 6 ; 
       FIG. 9  is an enlarged view of encircled area  9  of  FIG. 2   
       FIG. 10  is a perspective view of the structure of  FIG. 9 , from another vantage point; 
       FIG. 11  is a perspective view of the structure of  FIG. 9 , from another vantage point; 
       FIG. 12  is a perspective view of the structure of  FIG. 9 , from another vantage point; 
       FIG. 13A  is a view similar to  FIG. 5  of the valve of  FIG. 1 , showing a wax motor in a fully retracted arrangement and the valve in a bypass configuration thereof; 
       FIG. 13B  is a view similar to  FIG. 13A , showing the wax motor in a partially extended arrangement and the valve in a flowthrough configuration thereof; 
       FIG. 13C  is a view similar to  FIG. 13B , showing the wax motor in a fully extended arrangement and the valve in the flowthrough configuration thereof; 
       FIG. 14  is a schematic view of a valve similar to the valve of  FIG. 1  in use in an engine block casting; 
       FIG. 15  is a schematic view of a valve similar to the valve of  FIG. 1  in use in a radiator; 
       FIG. 16  is a view, similar to  FIG. 13A , of a valve according to a second embodiment of the invention; 
       FIG. 17  is a view, similar to  FIG. 13A , of a valve according to a third embodiment of the invention; 
       FIG. 18  is a view, similar to  FIG. 13A , of a valve according to a fourth embodiment of the invention; 
       FIG. 19  is a view, similar to  FIG. 13A , of a valve according to a fifth embodiment of the invention; 
       FIG. 20  is a phantom view of the valve of  FIG. 1 , showing a blacklined volume which represents the extent to which the flow ports are directly aligned; 
       FIG. 21  is a view, similar to  FIG. 19 , of a valve according to a sixth embodiment of the invention; and 
       FIG. 22  is a view, similar to  FIG. 19 , of a valve according to a seventh embodiment of the invention. 
   

   DETAILED DESCRIPTION 
   With general reference to  FIGS. 1-13C , a first embodiment of the present invention, a valve for use with a fluid such as engine coolant, is illustrated and is designated by the general reference numeral  20 . 
   With reference to  FIG. 2 , the valve  20  comprises a housing  22  and a valve cartridge  24 . 
   This housing  22  is of aluminum and includes a central portion  26  defining an open receptacle and three spigots  28 , 30 , 32  extending therefrom in a tee arrangement, each leading into the open receptacle. Two of the spigots  28 , 30  are substantially parallel and opposed to one another. The third spigot  32  extends transversely to the others. The inner surface  34  of the receptacle has a peripheral groove  36  extending therearound. 
   The valve cartridge  24  includes an aluminum insert  38 , an aluminum plug  40 , an actuator  42  and a rubber O-ring  44 . 
   The insert  38  has a peripheral groove  48  which receives the O-ring  44  and can be fitted in the receptacle  26  and secured in place with a spring clip  50  which interfits in groove  36 , as indicated in  FIG. 13A . So secured, the O-ring  44  sealingly engages each of the insert  38  and the inner surface  34  of the receptacle  26 , to seal the insert  38  and housing  22  to one another, such that the insert  38 , the O-ring  44  and the housing  22  together define a valve body. 
   With reference to  FIG. 13A , the valve body has a pair of flow ports  52 , 54 , an interior surface  56 , an axis X-X, an interior wall  58 , a further port  60 , a first valve seat  62  and a second valve seat  64 . The flow ports  52 , 54  are spaced-apart from, substantially opposed to and substantially aligned with one another, and communicate one each with the parallel spigots  28 , 30 . Flow ports  52 , 54  are each orientated substantially transverse to axis X-X. 
   In this disclosure and in the appended claims, “substantial alignment” of the flow ports  52 , 54  means that, if one were to project the flow ports across the valve body parallel to their respective flow directions, the projections would intersect to a substantial extent, as indicated by  FIG. 20 , wherein the valve is shown in phantom and the volume of intersection is indicated by the blacklined volume. 
   The interior surface  56  defines an interior chamber  66  of the valve body which is disposed between the flow ports  52 , 54  and communicates therewith. The axis X-X is aligned with the third spigot  32 , and orientated transversely to a flowthrough direction Y-Y with which the flow ports  52 , 54  are substantially aligned. The interior wall  58 : is a generally semi-cylindrical structure centred about the axis X-X; extends axially, partially across the interior chamber  66 ; defines, in combination with the interior surface  56 , an interior opening  68 ; and has a wall opening  70  therethrough. Wall opening  70  is opposed to and aligned with flow port  52 , i.e. wall opening  70  and flow port  52  present to one another. Flow port  54  and wall opening  70  are aligned, i.e. if one were to project flow port  54  parallel to its flow direction (not shown), the projection would intersect with wall opening  70  to a substantial extent. The interior wall  58 , in combination with portions of the valve body, notionally define a tubular structure, in which the interior opening  68  defines an open end and of which the interior wall  58  defines a side wall. The interior opening  68  provides for communication between a first subchamber  72  of the interior chamber  66  to which one  52  of the flow ports leads and a second subchamber  74  of the interior chamber  66  to which the other  54  of the flow ports leads. The second subchamber  74  extends partially around the side wall and beyond the open end of the tubular structure described hereinbefore. The wall opening  70  in the interior wall  58  also leads between the first  72  and second  74  subchambers. Both the interior wall  58  and the wall opening  70  thereof each circumscribe an angle of about 180°. The further port  60  provides for communication between second subchamber  74  and third spigot  32 . The first valve seat  62  surrounds the further flow port  60  and is defined by the interior surface  56  of the valve. The second valve seat  64  surrounds the interior opening  68 , is axially spaced from the first valve seat  62  and is defined by the interior surface  56  and by the end of the interior wall  58 . 
   As best seen in  FIGS. 6-8 , the plug  40  has a circular base portion  76  and a semi-cylindrical sidewall portion  78  extending from the base portion  76 . Sidewall portion  78  has a bisected plug opening  80  therein, and each of the side portion  78  and the plug opening  80  circumscribe an angle of about 180°. In  FIG. 13A , the plug  40  is shown in a first position in the interior chamber  66 . So positioned, base portion  76  and side portion  78  are both centred about the axis X-X, such that side portion  78  is concentric with the interior wall  58 , the interior wall  58  is nested within plug  40 , the base portion  76  is seated on the second valve seat  64 , the interior wall  58  overlies the plug opening  80  and the side portion  78  overlies the wall opening  70  to at least substantially isolate the first subchamber  72  of the interior chamber  66  from the second subchamber  74 . This defines an arcuate (or bypass, when the valve is used as a bypass valve) flow configuration of the valve  20 , whereat the valve  20  defines a further flow path B-B through the valve body between spigots  30 , 32  via flow port  54  and further port  60 . 
   The actuator  42  is for axially moving the plug  40  in the interior chamber between the first position shown in  FIG. 13A  and a second position shown in  FIG. 13B . In the second position of the plug  40 , the base portion  76  is seated on the first valve seat  62 , to at least substantially occlude the further port  60 . This defines a flowthrough configuration of the valve  20 , whereat the valve  20  defines a primary flow path F-F through the valve body between spigots  28 , 30  via flow ports  52 , 54 . In such configuration, it will be observed that the side portion  78  of the plug  40  and the interior wall  58  are arranged behind one another, to maximize the area through which fluid may flow. The primary flow path is a split-flow arrangement, with a first flow path between ports  52 , 54  being by way of the wall opening  70  and a second flow path between ports  52 , 54  being through the open end of the tubular structure, i.e. interior opening  68  and the plug opening  80 . In this position of the plug  40 , the plug opening  80  and flow port  54  are aligned. 
   With reference to  FIGS. 2 ,  6 - 8  and  13 B, the actuator  42  shown includes a wax motor  82 , a conical stainless steel return spring  84 , a stainless steel override spring  86  and an aluminum tubular sleeve  88 . The sleeve  88  has annular flanges  90 , 92  extending around each end and extends through an opening  98  in the circular base portion  76 . The flanges  90 , 92  provide for the sleeve  88  to be captured by the circular base portion  76 . The wax motor  82  is of a conventional type which includes a shell  91  having an enlarged head  89  from which a shaft  93  protrudes, the shaft  93  moving in response to thermally-induced expansion of the wax-like material (not shown) contained within the shell  91 . The motor  82  is fitted in the sleeve  88 , and a C-clip  94  is secured thereto, such that enlarged head  89  and the C-clip  94  capture therebetween the sleeve  88 . The shaft  93  projects from the wax motor  82  into a socket or recess  94  formed in the insert  38 . The conical return spring  84  extends between the sleeve flange  92  which is captured by the C-clip  94  and the bypass port  60 . The override spring  86  is fitted around the sleeve  88  and extends between the sleeve flange  90  which is captured by the enlarged head  89  and the base portion  76  of the plug  40 . 
   In operation, when the temperature of the wax in the wax motor  82  is below the wax-actuator set point, the wax-like material volume is relatively low, such that the shaft  93  can fit substantially within the shell  91 . Bias provided by the return spring  84  ensures that the shaft  93  is positioned within the shell  91  sufficient to enable flange  92  to retain base portion  76  of the plug  40  against the second valve seat  64 , as shown in  FIG. 13A . This corresponds to a fully retracted arrangement of wax motor  82 . 
   When the temperature of the wax-like material in the motor  82  reaches or exceeds the actuator set point temperature, the wax-like material expands. This causes shaft  93  to be partially expelled from the shell  91 . As the shaft  93  cannot extend through the socket  94 , extension of the shaft  93  from the shell  91  is accommodated by movement of the shell  91 , and the sleeve  88  by which it is mechanically captured, away from the socket  94 . Initially, as the shell  91  moves away from the socket  94 , bias provided by the override spring  86  causes the base portion  76  to remain engaged against flange  92  during such movement, such that movement of the shell  91  corresponds to movement of the plug  40 . In the course of such movement, the plug  40  will ultimately reach the second position, as shown in  FIG. 13B . This corresponds to a partially-extended arrangement of the wax motor  82 . At this point, the base portion  76  of the plug  40  is seated against the first valve seat  62 , and can move no further; if the wax-like material requires further expansion volume, this will be accommodated by movement of the sleeve  88  through the opening  98  in the base portion  76 , as shown in  FIG. 13C . This corresponds to a fully-extended arrangement of the wax motor  82 . Persons of ordinary skill will recognize that this arrangement is advantageous, since the shaft extension in any given wax motor or in a manufactured batch thereof can vary. By providing an override spring arrangement, a valve designer can ensure that the valve will move predictably between the first and second positions in response to temperature change, and can also avoid undue stresses in the valve that might follow if accommodation was not made for overextension. 
   When the temperature of the wax-like material in the wax motor  82  falls beneath the set point, the conical return spring  84  will drive the shell  91  back over the shaft  93 . Until such time as flange  92  of the sleeve  88  engages base portion  76 , bias provided by override spring  86  will maintain base portion  76  seated against the first valve seat  62 . Expansion of the conical spring  84  beyond that point will result in movement of the sleeve  88  and plug  40  together, during which movement, the interior wall  58  telescopes into the plug  40 . Ultimately, the plug  40  returns to the first position, and further movement is arrested by engagement of the base portion  76  with the second valve seat  64 . 
   In one use, the valve of  FIG. 1  is used as a bypass valve and deployed in an automobile cooling circuit. In this use (not shown), spigot  30  receives a hose (not shown) through which coolant from the engine is received, spigot  28  is coupled by a hose to the radiator inlet (neither shown) and the further spigot  32  is coupled by a hose through which coolant is delivered to the engine. When the coolant temperature is below the wax actuator set point (and wherein the coolant is not sufficiently heated to be required to shed heat), the wax-motor is maintained in the fully-retracted position, the plug is disposed in the first position and the valve is disposed in the bypass configuration, such that most of the coolant follows path B-B back to the engine. Thus, in this use, port  54  is an inlet port and ports  52 ,  60  are outlet ports. In the bypass configuration, leak paths exist in the seal between the base portion  76  of the plug  40  and the second valve seat  64 , in the junction between interior portion  58  and side portion  78 , in the junction between sleeve  88  and opening  98  in the base portion  76  and in the junction between the shell  91  and the sleeve  88 . Thus, the wax motor  82  is not entirely isolated from the flow, so as to be susceptible to actuation when the flow temperature exceeds the wax set point. When this occurs, the plug  40  moves to the second position and the valve assumes the flowthrough configuration, such that most of the coolant follows flow path F-F through the radiator before being returned to the engine. Again, in this configuration, leak paths will exist, in the seal between the base portion  76  of the plug  40  and the first valve seat  64 , in the junction between interior wall  58  and side portion  78 , in the junction between sleeve  88  and opening  98  in the base portion  76  and in the junction between the shell  91  and sleeve  88 . 
   A similar use is shown schematically in  FIG. 14 . Herein, a valve  20 ′ similar to that of  FIG. 1  but lacking spigots is fitted in an engine block casting  99 , with the flow ports forming part of the coolant circuit (not shown) from the engine to the radiator and the bypass port coupled to a circuit (not shown) which bypasses the radiator and returns to the engine. The operation of this valve  20 ′ is functionally identical to the valve  20  and use thereof previously described, and thus is not further described herein. 
   A further use of the valve  20 ′ of  FIG. 14  is shown schematically in  FIG. 15 . Herein the valve  20 ′ is fitted in a radiator  101 , with the flow ports forming part of a heat exchanging circuit  103  through which coolant is caused to traverse the heat exchanger  101  and shed heat before returning to the engine, and the bypass port forming part of a circuit  105  which bypasses the heat-exchanging portion of the radiator in its return to the engine. Again, the operation of this valve  20 ′ is functionally identical to the valve  20  and uses thereof previously described, and thus is not further described herein. 
   It is notable that in each of the valves and uses described, there is found a cartridge  24  which contains all of the moving parts of the valve, so as to advantageously permit ready removal and replacement as required. The present valve has also been found to have relatively low pressure losses in use, which is known to be advantageous in the automotive field since it permits relatively smaller and lighter pumps to be utilized, with commensurate savings in automobile cost and weight. 
   Without intending to be bound by theory, it is believed that the advantageous flow characteristics of the present valve derive from the shape of the valve and its components. Notable in this regard, the primary flow path is substantially parallel to the flows leading to and from the valve. Further, each of the primary and further flow paths is free of substantial constrictions over their respective lengths owing, inter alia, to the relatively large volume of the second subchamber  74  which the flow traverses in the arcuate or bypass configuration of the valve, and to the relatively large area of openings  70 , 80  (similar in size to the area of each of the flow and further ports  52 , 54 , 60 ) through which the flow traverses in the flowthrough configuration of the valve. Additionally of note is the shape of the second subchamber  74  of the interior chamber, specifically, the upper portion thereof having a C-shaped or arcuate cross-section, which permits the flow entering from flow port  54  to spread out, around the side wall  78 /interior wall  58 , before passing under the base portion  76  and exiting the valve through the port  60 . 
   Various other embodiments of the valve are shown in  FIGS. 16-18 . These valves are similar in function to the valve of  FIGS. 1-13C , but whereas the valve of  FIGS. 1-13C  employs a wax motor to drive the plug between the first and second positions, these valves employ other forms of actuators to accomplish the same function.  FIG. 16  shows a valve  20 ″ wherein the plug  40  has a threaded post  100  axially extending therefrom which is received by an internally-threaded driveshaft  102  coupled to a motor  104 . The motor  104  can rotate the drive shaft  102 , which rotates about the threaded post  100 , so as to result in axial movement of the post  100  and consequent movement of the plug  40  between the first and second positions.  FIG. 17  shows a valve  20 ′″ wherein a rack  106  extends from the plug  40 , a pinion  108  is in mesh with the rack  106  and a motor  110  is drivingly coupled to the pinion  108 . Herein, the motor  110  rotates the pinion  108  which drives the rack  106  axially to move the plug  40  between the first and second positions,  FIG. 18  shows yet another valve  20 ″″ wherein a cam follower  112  is coupled to the plug  40 , a cam  114  is engaged with the cam follower and a stepper motor  116  is coupled to the cam  114 . Herein, the stepper motor  116  rotates the cam  114  to engage the cam follower  112  and drive the plug axially between the first and second positions. In each of these cases, some form of external sensor or control would be used to trigger the movement of the plug. As the construction of actuators, sensors and controls of this type is routine to persons of ordinary skill in the art, and as the valves  20 ″,  20 ′″,  20 ″″ operate in a manner substantially similar to valves  20  and  20 ′, further description as to their respective construction and operation is neither necessary nor provided. 
   A further possible modification is shown in the valve  20 ′″″ of  FIG. 21  which is similar to the valve of  FIG. 18 , but also includes a tubular skirt  120  which extends from the plug and telescopes into the further port. Herein, flow through the further port is restricted, by virtue of its need to pass through holes  122  defined in the skirt  120 . By changing the shapes/sizes of holes  122 , the flow characteristics of this valve can be modified at different points during movement between the first and second positions, to allow flow to be metered or linearized. In addition to the metering functionality, the skirt provides prealignment of the plug, which can assist in sealing and avoid binding. 
   A yet further modification is shown in the modified valve  20 ″″″ of  FIG. 21 . This valve is substantially similar to the valve of  FIG. 18 , but lacks the further “bypass” port. 
   Whereas numerous embodiments and uses of the valve have been herein shown in described, it will be understood that various modifications can be made. 
   For example, whereas the valve is herein sometimes shown and illustrated as a bypass valve, wherein an input or inlet flow is directed to one of two outputs or outlets, it will be evident that the valve could be used as a mixing valve, wherein flow is selectively received from one of two inputs and delivered to a single output. In applications wherein port  52  is deployed as an inlet port, fluid pressure may tend to separate walls  78 , 58 , and to avoid this, a skirt as shown in  FIG. 21  may be advantageously utilized to stabilize the plug. 
   As well, whereas the description teaches movement of the plug between the first and second positions, it will be evident that the plug can assume intermediate positions, if flow is to be split, or if a split flow is to be received. In this case, of course, an actuator capable of moving the plug partially between the first and second positions, such as one of the actuators shown in  FIGS. 16-18 , would be used in substitution for wax motors which, while relatively inexpensive, robust and reliable in comparison to the actuators of  FIGS. 16-18 , generally lack proportional responsiveness, i.e. reliably move only between the fully retracted and the fully extended arrangements. 
   Further, whereas the valves illustrated and described have relatively good flow characteristics, improvements are contemplated to be achievable through interior contouring or streamlining, as suggested in  FIG. 19 , wherein a portion  56 A of the interior surface  56  has been contoured for flow conditioning. 
   Yet further, whereas the valve of  FIGS. 1-13C  is indicated to be constructed of steel, aluminum and rubber, it will be evident that other materials, such as plastics, could readily be employed. 
   Additionally, although the valves shown and described herein are indicated to be of a cartridge type, so as to permit ready removal and replacement of the moving parts of the valve in the event of failure or excess wear, it will be evident that a cartridge-type construction need not be employed. 
   Moreover, whereas the plug opening shown and described is indicated to be bisected, it will be evident that this is not necessary. The plug opening could equally be defined by a single aperture, or by three or more apertures. Further, whereas the side portion of the plug and the interior portion are herein indicated to be semi-cylindrical and to circumscribe at least about 180°, this is not necessary. Semi-elliptical cross-sections might, for example, be employed, if a relatively “flatter” and “wider” valve was required. Additionally, whereas the flow ports and wall opening are substantially opposed to one another as shown in the illustrations, it should be understood that flow ports need not be opposed to one another, but could be disposed in angular relation to one another. 
   Further, whereas the interior wall is herein shown to partially divide the interior chamber, it is contemplated that the interior wall could extend fully across the interior chamber. In this arrangement, the plug would likely telescope interiorly into the first subchamber, and some form of perforation or aperture in the interior wall would likely be required to be provided, to mate with the plug opening when the plug is at the second position. 
   Additionally, it should be understood that “seal”, as used in the disclosure and in the appended claims, does not necessarily contemplate a complete blockage of flow, but rather simply means that the parts in question cooperate or interact to restrict or arrest flow. 
   In view of the foregoing, it should be understood that the invention is limited only by the claims appended hereto, purposively construed.