Patent Publication Number: US-2012024398-A1

Title: Multi-way reversing valve

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Japanese Patent Application No. 2010-169241, filed Jul. 28, 2010, all of which is herein incorporated by reference in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to multi-way reversing valves, such as three-way reversing valves, four-way reversing valves, etc., employed in heat pumps, etc., and, more particularly, to rotary multi-way reversing valves that reverse flow paths by rotating a valve member by means of an actuator, such as, for example, a motor, etc., including a rotor and a stator. 
     2. Background Art 
     Heat pumps (refrigeration cycles) employed in air conditioners, refrigeration units, etc., generally include a four-way reversing valve as a flow path (flow direction) reversing means, in addition to a compressor, a gas-liquid separator, a condenser (outdoor heat exchanger), an evaporator (indoor heat exchanger), an expansion valve, etc. 
     As disclosed in JP Patent Publication (Kokai) No. 2001-295951 A (Patent Document 1, the entire contents of which is herein incorporated by reference in its entirety), such four-way reversing valves employed in heat pumps, etc., typically include: a valve member adapted to be rotated by an actuator, such as a motor, etc.; and a valve body in which are provided a valve seat part and valve chamber that rotatably hold the valve member. A first inlet/outlet (condenser communication port), a second inlet/outlet (evaporator communication port), a high-pressure inlet for introducing a high-pressure refrigerant from the compressor discharge side into the valve chamber, and a low-pressure outlet for evacuating a low-pressure refrigerant to the compressor suction side are provided in the valve seat part of the valve body. Flow paths are typically reversed by rotating the valve member to selectively place one of the first inlet/outlet and the second inlet/outlet in communication with one of the high-pressure inlet (valve chamber) and the low-pressure outlet through a passage part provided within the valve member. 
     However, such rotary four-way reversing valves are adapted to have a high-pressure refrigerant introduced into the valve chamber, while at the same time a low-pressure refrigerant is passed through the passage part within the valve member. Consequently, the differential pressure between the interior and exterior of the valve member becomes extremely large, and the valve member is pressed strongly against the valve seat part due to that differential pressure (the high-pressure refrigerant). As a result, there are such problems as there being a tendency for the valve member to not rotate smoothly when reversing flow paths, thereby making the flow path reversing operation heavy, as well as the valve member and valve seat part being prone to wear. 
     In order to address such problems, the present inventors have previously proposed a four-way reversing valve of the following configuration—JP Patent Application No. 2009-203926 (Patent Document 2), the entire contents of which is herein incorporated by reference in its entirety. 
     Specifically, as shown in FIGS.  5  and  6 A- 6 D, the proposed four-way reversing valve  1 ′ includes: in order to reverse flow paths, an actuator  15 , such as a motor, etc., having a rotor  16  disposed within a can  38  and a stator  17  disposed on the outer circumference of the can  38 ; a valve member  50  adapted to be rotated by an output shaft of a planetary gear reduction system  40  that reduces the output of the actuator  15 ; and a valve body  60  adapted to rotatably hold the valve member  50 . A high-pressure passage part  55  adapted to have a high-pressure refrigerant introduced thereinto is formed within the valve member  50 . A valve seat part  65  and a valve chamber  61  are provided in the valve body  60 . The valve seat part  65  is provided with a first inlet/outlet  13  and a second inlet/outlet  14  adapted to be selectively placed in communication with an outlet of the high-pressure passage part  55 . The valve chamber  61  is adapted to have a low-pressure refrigerant selectively introduced thereinto via the first inlet/outlet  13  or the second inlet/outlet  14 . The dimensions and shapes of the valve member  50 , etc., are designed in such a manner that, during flow path reversal, an outlet-side end part of the high-pressure passage part  55  of the valve member  50  would slide between the first inlet/outlet  13  and second inlet/outlet  14  of the valve seat part  65 , and that the force in the direction in which the valve member  50  is pressed against the valve seat part  65  by the high-pressure refrigerant would be substantially cancelled. 
     More specifically, the valve body  60  includes an upper body  60 A and a lower body  60 B that are fastened by a plurality of screws  93 . The valve member  50  is so disposed as to pass through a through-hole  67  provided in the center of the valve seat part  65 , and is rotatably supported inside the valve body  60  via shaft bearings  81  and  82 . Further, in order to place an outlet  55   a  of the high-pressure passage part  55  in tight contact with the valve seat part  65 , an O-ring  74  and a square ring  75  are disposed at the outlet  55   a . The valve member  50  is pressed upward by a coil spring  92  compressed and loaded between itself and the lower body  60 B. The valve member  50  includes an inverted L-shaped shaft part  53 . The high-pressure passage part  55  of an inverted L-shape or crank shape for selectively guiding the high-pressure refrigerant to the first inlet/outlet  13  or the second inlet/outlet  14  is formed within the inverted L-shaped shaft part  53 . In addition, a high-pressure inlet  11  for guiding the high-pressure fluid to the high-pressure passage part  55  of the valve member  50  is provided in the bottom part of the valve chamber  61  opposite the valve seat part  65 . Further, a low-pressure outlet  12  that opens into the valve chamber  61  is provided. Thus, it is adapted to function as a four-way reversing valve to be employed in the aforementioned heat pump devices. 
     The reference numerals  63  and  64  represent flow paths that are provided in the valve body  60  and that place the first inlet/outlet  13  and the second inlet/outlet  14  in communication with the exterior of the electrically operated valve. 
     In addition, in order to introduce into the can  38  the refrigerant that flows into the valve chamber  61 , communication holes and gaps provided between the various members are provided at key parts of the electrically operated valve. 
     It is noted that, in order to facilitate a better understanding,  FIG. 5  is drawn as if the first inlet/outlet  13 , the second inlet/outlet  14 , and the flow paths  63  and  64  are disposed further into the sheet. However, their actual positional relationship is as shown in  FIGS. 6A-6D . 
     With the four-way reversing valve  1 ′, the high-pressure passage part  55  into which the high-pressure refrigerant is introduced is formed in the valve member  50 , and the low-pressure refrigerant is introduced into the valve chamber  61 . Further, the dimensions and shapes of the valve member  50 , etc., are so designed that the force in the direction in which the valve member  50  is pressed against the valve seat part  65  by the high-pressure refrigerant would be substantially cancelled. Thus, it is possible to perform the flow path reversing operation with ease, and the valve member  50  and valve seat part  65  become less prone to wear. As a result, durability and reliability improve. 
     SUMMARY 
     However, with the related art rotary four-way reversing valve  1 ′ described above, the valve member  50  is rotated from the position shown in  FIG. 6A  (hereinafter, first operating position) to the position shown in  FIG. 6D  (hereinafter, second operating position), or vice versa, to reverse flow paths, that is, to switch between, for example, a cooling operation state where the first inlet/outlet  13  and the high-pressure passage part  55  are placed in communication while the second inlet/outlet  14  and the low-pressure outlet  12  are placed in communication, and, for example, a heating operation state in which the second inlet/outlet  14  and the high-pressure passage part  55  are placed in communication while the first inlet/outlet  13  and the low-pressure outlet  12  are placed in communication. 
     In this case, during the transitional stage of flow path reversal (i.e., in the middle of switching from the first operating position to the second operating position, or from the second operating position to the first operating position), as shown in  FIGS. 6B and 6C , the outlet-side end part  55   a  (the square ring  75 ) of the high-pressure passage part  55  of the valve member  50  slides while being pressed against the part of the valve seat part  65  between the first inlet/outlet  13  and the second inlet/outlet  14 . Consequently, the outlet of the high-pressure passage part  55  is closed off by the valve seat part  65 . 
     When the outlet side of the high-pressure passage part  55  is thus closed off during the transitional stage of flow path reversal, the high-pressure refrigerant of the compressor discharge side is generally left with no place to escape to, albeit for a short time. Therefore, unless the operation of the compressor is suspended, the pressure of the high-pressure refrigerant would rise sharply, which may result in such problems as the flow path reversing operation being disrupted, devices erratically ceasing operation due to an erroneous determination of an anomaly/failure in the device by a fail-safe mechanism, and so forth. 
     The present disclosure is made in view of such circumstances, and an aspect thereof is to provide a multi-way reversing valve in which the pressure of the high-pressure refrigerant is prevented from increasing excessively during the transitional stage of flow path reversal without suspending the operation of the compressor, thereby preventing problems in the flow path reversing operation, while at the same time preventing situations where devices would erratically cease operating as a result of erroneous determinations of an anomaly/failure in the device being made by a fail-safe mechanism. 
     In view of the aspect above, a multi-way reversing valve according to an exemplary embodiment of the present disclosure may include: a valve member adapted to be rotated by an actuator, such as a motor or the like, in order to reverse flow paths; and a valve body adapted to rotatably hold the valve member, wherein a high-pressure passage part adapted to have a high-pressure fluid introduced thereinto is formed within the valve member, a valve seat part is provided in the valve body, the valve seat part having a plurality of flow-out ports formed therein, the plurality of flow-out ports being adapted to be selectively placed in communication with an outlet of the high-pressure passage part, an outlet-side end part of the high-pressure passage part of the valve member is adapted to slide while being pressed against the valve seat part during a transitional stage of flow path reversal, and positions, dimensions, shapes and the like of the outlet of the high-pressure passage part and of the plurality of flow-out ports are designed in such a manner that, even during the transitional stage of flow path reversal, the outlet of the high-pressure passage part would always be in communication with at least one of the plurality of flow-out ports. 
     More preferably, a multi-way reversing valve according to an embodiment of the present disclosure may include: a valve member adapted to be rotated by an actuator, such as a motor or the like, in order to reverse flow paths; and a valve body adapted to rotatably hold the valve member, wherein a high-pressure passage part adapted to have a high-pressure fluid introduced thereinto is formed within the valve member, a valve seat part and a valve chamber are provided in the valve body, the valve seat part having a first inlet/outlet and a second inlet/outlet formed therein, the first inlet/outlet and the second inlet/outlet being adapted to be selectively placed in communication with an outlet of the high-pressure passage part, the valve chamber being adapted to have a low-pressure fluid selectively introduced thereinto via the first inlet/outlet or the second inlet/outlet, an outlet-side end part of the high-pressure passage part of the valve member is adapted to slide between the first inlet/outlet and the second inlet/outlet of the valve seat part during flow path reversal, and positions, dimensions, shapes and the like of the outlet of the high-pressure passage part, as well as of the first inlet/outlet and the second inlet/outlet are designed in such a manner that, even during a transitional stage of flow path reversal, the outlet of the high-pressure passage part would always be in communication with at least one of the first inlet/outlet and the second inlet/outlet. 
     The valve member and the high-pressure passage part may preferably be formed in an L-shape or crank shape as viewed from the side. 
     The diameter of each of the plurality of flow-out ports may preferably be adapted to be smaller than the diameter of the outlet of the high-pressure passage part. 
     In another preferred embodiment, the outlet of the high-pressure passage part and at least one of the plurality of flow-out ports may be located along the circumference of the same circle. 
     In another preferred embodiment, the offset distance among the plurality of flow-out ports may be adapted to be shorter than the diameter of the outlet of the high-pressure passage part. 
     With a multi-way reversing valve according to a preferred embodiment of the present disclosure, the positions, dimensions, shapes, etc., of the outlet of the high-pressure passage part and of the first inlet/outlet and the second inlet/outlet are designed in such a manner that, even during the transitional stage of flow path reversal, the outlet of the high-pressure passage part within the valve member would always be in communication with at least one of the first inlet/outlet and the second inlet/outlet. Thus, during the transitional stage of flow path reversal, the high-pressure refrigerant of the compressor discharge side is allowed to escape from the high-pressure passage part within the valve member to the valve chamber or out of the valve via the first inlet/outlet and/or the second inlet/outlet. As a result, it is possible to prevent the pressure of the high-pressure refrigerant from increasing excessively during the transitional stage of flow path reversal without suspending the operation of the compressor, thereby preventing problems in the flow path reversing operation, while at the same time preventing situations where devices would erratically cease operating as a result of erroneous determinations of an anomaly/failure in the device being made by a fail-safe mechanism. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic sectional view showing a key part of a multi-way (four-way) reversing valve according to the first embodiment of the present disclosure. 
         FIGS. 2A through 2C  are sectional views taken as indicated by arrowed line Y-Y in  FIG. 1 . 
         FIGS. 3A through 3C  are sectional views respectively corresponding to  FIGS. 2A through 2C  and which show the second embodiment. 
         FIGS. 4A through 4C  are sectional views respectively corresponding to  FIGS. 2A through 2C  and which show the third embodiment. 
         FIG. 5  is a vertical sectional view showing one example of a related art multi-way (four-way) reversing valve. 
         FIGS. 6A through 6D  are sectional views taken as indicated by arrowed line X-X in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION 
     Four-way reversing valves according to embodiments of the present disclosure are described below with reference to the drawings. 
       FIG. 1  is a schematic sectional view showing a key part of a multi-way (four-way) reversing valve according to the first embodiment of the present disclosure (the second and third embodiments are generally similar).  FIGS. 2A through 2C  are sectional views taken as indicated by arrowed line Y-Y in  FIG. 1 .  FIGS. 3A through 3C  and  4 A through  4 C are sectional views respectively corresponding to  FIGS. 2A through 2C , and which respectively show the second and third embodiments. It is noted that, for the respective four-way reversing valves  1  of these embodiments, parts that find correspondence in the related art four-way reversing valve  1 ′ shown in  FIG. 5  discussed above are designated with like reference numerals while omitting redundant descriptions with regard thereto. 
     The first through third embodiments of the present disclosure are applicable to eclectically operated valves in which a low-pressure refrigerant is introduced into the valve chamber and in which a high-pressure refrigerant is introduced into the valve member disposed within the valve chamber as discussed in connection with  FIG. 5 .  FIG. 1  shows a schematic configuration for the valve chamber and valve member shown in  FIG. 5 . 
     As with the related art example shown in  FIG. 5 , the four-way reversing valve  1  of the illustrated example is also employed in heat pump devices for car air-conditioners, etc., and includes a valve member  20  that is rotated by a motor (not shown), and a valve body  30  that rotatably holds this valve member  20 . 
     The valve member  20  is formed in an L-shape or crank shape as viewed from the side. On the upper surface thereof is provided, in a protruding manner, a support shaft  23  that is inserted into a shaft bearing hole  33  formed in the center (along rotational axis O) of an upper part (valve seat part)  35  of the valve body  30 . This support shaft  23  is connected with the rotational output shaft of the actuator, such as a motor, etc., which is not shown in the drawing. A high-pressure passage part  25  into which a high-pressure refrigerant is to be introduced is formed inside the valve member  20  in a shape similar to the external shape thereof. 
     A high-pressure inlet  11  and a low-pressure outlet  12  (both of which do not appear in the drawing, see  FIG. 5 ) as well as a valve chamber  31  are formed in the valve body  30 . Further, a first inlet/outlet  13  and a second inlet/outlet  14  (omitted in  FIG. 1 ), which are selectively placed in communication with an outlet  25   a  (the inner side of a square ring  75 ) of the high-pressure passage part  25  of the valve member  20  are formed in the valve seat part  35  of the valve body  30 . 
     In addition, with respect to the four-way reversing valve  1  in the illustrated example, (center line Ca of) the outlet  25   a  of the high-pressure passage part  25  and (center line Cb of) the first inlet/outlet  13  are located along the circumference of the same circle (D 1 ). The diameter of the first inlet/outlet  13  is designed to be slightly smaller than the diameter of the outlet  25   a  of the high-pressure passage part  25 . The diameter of the second inlet/outlet  14  is designed to be considerably smaller than the diameter of the first inlet/outlet  13 . 
     With the four-way reversing valve  1  in this example, the positions, dimensions, shapes, etc., of the outlet  25   a  of the high-pressure passage part  25  as well as of the first inlet/outlet  13  and second inlet/outlet  14  are designed in such a manner that the outlet  25   a  of the high-pressure passage part  25  would always be in communication with at least one of the first inlet/outlet  13  and the second inlet/outlet  14  even during the transitional stage of flow path reversal, that is, in such a manner that the outlet  25   a  of the high-pressure passage part  25  would typically never be completely closed off by the valve seat part  35  during the transitional stage of flow path reversal. 
     Specifically, in the first embodiment ( FIGS. 2A through 2C ), (center line Cc of) the second inlet/outlet  14  is located along the circumference of circle D 1  mentioned above. In the second embodiment ( FIGS. 3A through 3C ), (center line Cc of) the second inlet/outlet  14  is located along the circumference of circle D 2 , which is larger than circle D 1  mentioned above. In the third embodiment ( FIGS. 4A through 4C ), (center line Cc of) the second inlet/outlet  14  is located along the circumference of circle D 3 , which is smaller than circle D 1  mentioned above. In all of these embodiments, offset distance (shortest linear distance) Lb between the first inlet/outlet  13  and the second inlet/outlet  14  is designed to be shorter than diameter La of the outlet  25   a  of the high-pressure passage part  25 . 
     With respect to the thus configured four-way reversing valve  1 , by rotating the valve member  20  from the position shown in  FIG. 2A  (first operating position) to the position shown in  FIG. 2C  (second operating position), or vice versa, flow paths are reversed, that is, switching is performed between, by way of example, a cooling operation state, in which the first inlet/outlet  13  and the high-pressure passage part  25  are placed in communication while the second inlet/outlet  14  and the low-pressure outlet  12  are placed in communication, and, by way of example, a heating operation state, in which the second inlet/outlet  14  and the high-pressure passage part  25  are placed in communication while the first inlet/outlet  13  and the low-pressure outlet  12  are placed in communication. 
     In this case, during the transitional stage of flow path reversal (i.e., in the middle of switching from the first operating position to the second operating position, or from the second operating position to the first operating position), as shown in  FIGS. 2B ,  3 B and  4 B, the outlet side end part (the square ring  75 ) of the high-pressure passage part  25  of the valve member  20  slides while being pressed against the part of the valve seat part  35  between the first inlet/outlet  13  and the second inlet/outlet  14 . 
     With the respective four-way reversing valves  1  of the embodiments above, by, for example, designing offset distance (shortest linear distance) Lb between the first inlet/outlet  13  and the second inlet/outlet  14  to be shorter than diameter La of the outlet  25   a  of the high-pressure passage part  25  as discussed above, the outlet  25   a  of the high-pressure passage part  25  is made to always be in communication with at least one of the first inlet/outlet  13  and the second inlet/outlet  14  even during the transitional stage of flow path reversal (in  FIGS. 2B ,  3 B and  4 B, there are shown states in which the outlet  25   a  of the high-pressure passage part  25  slightly opens into both the first inlet/outlet  13  and the second inlet/outlet  14 ). Thus, during the transitional stage of flow path reversal, the high-pressure refrigerant of the compressor discharge side is allowed to escape from the high-pressure passage part  25  to the valve chamber  31  or out of the valve via the first inlet/outlet  13  and/or the second inlet/outlet  14 . As a result, it is possible to prevent the pressure of the high-pressure refrigerant from increasing excessively during the transitional stage of flow path reversal without suspending the operation of the compressor, thereby preventing problems in the flow path reversing operation, while at the same time preventing situations where devices would erratically cease operating as a result of erroneous determinations of an anomaly/failure in the device being made by a fail-safe mechanism. 
     It is noted that the positions, dimensions, shapes, etc., of the outlet  25   a  of the high-pressure passage part  25 , as well as of the first inlet/outlet  13  and the second inlet/outlet  14 , are by no means limited to those of the embodiments above, and that various modifications are possible. For example, it is noted that the diameters of the first inlet/outlet  13  and second inlet/outlet  14  may be made the same, and that the outlet  25   a  of the high-pressure passage part  25 , the first inlet/outlet  13 , and the second inlet/outlet  14  may be of shapes other than a circle (e.g., an ellipse, a rectangle with rounded corners, etc.). 
     Further, although in the embodiments above, a four-way reversing valve for use in heat pump devices is addressed, the present disclosure is by no means limited as such. Instead, it is similarly applicable to a three-way reversing valve in which there are two flow-out ports (or inlet/outlets) that may be selectively placed in communication with the outlet of the high-pressure passage part (i.e., a valve in which the low-pressure outlet  12  is dropped from the embodiments above), a four-way reversing valve, five-way reversing valve, etc., in which there are three or more high-pressure flow-out ports (or inlet/outlets). 
     In addition, the motor that rotates the valve member may be of any type. Further, whether or not to provide a reduction system between the motor and the valve member may be determined as deemed appropriate in accordance with, for example, the specifications of the heat pump device, etc., in which the electrically operated valve in question is to be employed. 
     Although the systems and methods of the present disclosure have been described with reference to exemplary embodiments thereof, the present disclosure is not limited to such exemplary embodiments and/or implementations. Rather, the systems and methods of the present disclosure are susceptible to many implementations and applications, as will be readily apparent to persons skilled in the art from the disclosure hereof The present disclosure expressly encompasses such modifications, enhancements and/or variations of the disclosed embodiments. Since many changes could be made in the above construction and many widely different embodiments of this disclosure could be made without departing from the scope thereof, it is intended that all matter contained in the drawings and specification shall be interpreted as illustrative and not in a limiting sense. Additional modifications, changes, and substitutions are intended in the foregoing disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the disclosure. 
     List of Reference Numerals 
       1  Four-way reversing valve 
       11  High-pressure inlet 
       12  Low-pressure outlet 
       13  First inlet/outlet 
       14  Second inlet/outlet 
       20  Valve member 
       25  High-pressure passage part 
       25   a  Outlet 
       30  Valve body 
       31  Valve chamber 
       35  Valve seat part