JP6533111B2 - Refrigerant switching valve - Google Patents

Description

  The present invention relates to a refrigerant switching valve, and more particularly to a refrigerant switching valve that switches the flow of refrigerant in a refrigeration cycle.

  The refrigerator is provided with a refrigerant switching valve for the purpose of flowing the refrigerant of the refrigeration cycle to a heat exchanger (evaporator) to generate cold air, or flowing the hot refrigerant to partition walls in the refrigerator or the like to prevent condensation. It is done. For example, such a refrigerant switching valve is described in JP-A-2015-77015 (Patent Document 1).

  This patent document 1 discloses a four-way valve provided with a valve main body in which a conduction path capable of switching the communication state between one refrigerant inlet and three refrigerant communication ports is formed. The four-way valve is driven by the electric motor, and when the electric motor is rotated by a control signal from a control device (not shown), the position of the valve body of the four-way valve is changed corresponding to the rotation. As a result, the communication state between at least one refrigerant inlet and three refrigerant communication ports is switched. In addition, although many such refrigerant | coolant switching valves exist besides patent document 1, further description is abbreviate | omitted here.

JP, 2015-77015, A

  By the way, in the refrigerant switching valve disclosed in Patent Document 1, a flat valve seat (= sliding contact surface) in which each refrigerant communication passage is opened, and a valve body of the refrigerant switching valve disposed opposite to this. Each refrigerant communication passage is opened and closed by the sliding contact surface. The valve body and the valve seat are disposed in a sealed space (switch valve chamber), and the refrigerant flowing from the refrigerant inlet is a high pressure refrigerant. For this reason, since the high pressure refrigerant presses the valve body toward the valve seat, a large contact pressure acts between the valve body and the valve seat, and as a result, the slide between the valve body and the valve seat Dynamic resistance increases.

  If the sliding resistance increases, the sliding between the valve body and the valve seat can not be smoothed, and at least the problem that the predetermined operation can not be obtained unless the electric power supplied to the electric motor is increased, or the rotation of the valve body One or more of the problems occur that the operation is delayed and smooth refrigerant switching can not be performed, or that the valve main body does not rotate to a predetermined position and the refrigerant switching itself can not be performed. Therefore, there is a need for measures to solve any of these problems.

  An object of the present invention is to provide a novel refrigerant switching valve capable of solving the at least one of the above-mentioned problems by reducing the sliding resistance between the valve body and the valve seat.

  The basic feature of the present invention is that the sliding contact surface of the valve body that slides with the valve seat is formed with a recess that does not have the function of allowing the coolant to flow separately from at least the channel through which the coolant flows. There is a reduced contact area.

  According to the present invention, the sliding contact area of the sliding contact surface of the valve body is reduced by the recess, so that the sliding resistance can be reduced, and at least one of the above-mentioned problems can be solved.

It is an explanatory view explaining basic composition of a refrigerator to which the present invention is applied. It is a top perspective view of the refrigerant switching valve according to the present invention. It is a longitudinal cross-sectional view of the refrigerant | coolant switching valve shown in FIG. It is a top perspective view of the refrigerant | coolant switching valve of the state which removed the stator case and valve case of the refrigerant | coolant switching valve shown in FIG. It is a cross-sectional view of valve seat plate vicinity of a refrigerant | coolant switching valve shown in FIG. It is a longitudinal cross-sectional view along the KK line of FIG. It is a disassembled perspective view which shows the structure of the rotor pinion gear of the refrigerant | coolant switching valve field shown in FIG. 2, an idler gear, and a valve body. It is a block diagram which shows the refrigerating cycle which used the refrigerant | coolant switching valve of this embodiment. It is explanatory drawing explaining the opening of the refrigerant | coolant communication path of the refrigerant | coolant switching valve shown in FIG. 2, and the relationship of a valve body sliding contact surface. It is a top perspective view of the valve body of the refrigerant switching valve which shows the typical embodiment of the present invention. It is a lower surface perspective view of the valve main body of the refrigerant | coolant switching valve shown in FIG. It is explanatory drawing explaining the relationship of the opening of the valve-body sliding contact surface of the valve main body shown to FIG. 10, FIG. 11, and a refrigerant | coolant communication path. It is explanatory drawing explaining the relationship between the distance between the refrigerant | coolant conduction path and opening which were formed in the valve-body sliding contact surface of the valve main body shown in FIG. 11, and process capability index CP value. It is an explanatory view explaining the 1st change state of the refrigerant switching valve which becomes this embodiment. It is an explanatory view explaining the 1st transition state which changes to the 2nd switching state from the 1st switching state of a refrigerant switching valve. It is an explanatory view explaining the 2nd transition state which changes from the 1st change over state of a refrigerant switching valve to the 2nd change over state. It is explanatory drawing explaining the 3rd transition state which changes to the 2nd switching state from the 1st switching state of a refrigerant | coolant switching valve. It is explanatory drawing explaining the 2nd switching state of the refrigerant | coolant switching valve which becomes this embodiment.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and applications may be made within the technical concept of the present invention. Is included in the range.

  Hereinafter, modes for carrying out the present invention (hereinafter, referred to as “embodiments”) will be described in detail with reference to the drawings as appropriate.

  Before describing the present invention, the configuration of a refrigerator related to the present invention will be briefly described. As shown in FIG. 1, the front opening of each storage room of the refrigerator 1 is configured to be openable and closable by a door, and a double door type cold storage room door 2a, 2b and the like which rotate around a hinge not shown from the top. The drawer type ice storage room door 3, the upper stage freezer room door 4, the lower stage freezer room door 5, and the vegetable room door 6 are arranged. It should be noted that, except for the refrigerator compartment doors 2a and 2b, they are all drawer type doors, and these drawer type doors 3 to 6 are configured such that when the doors are pulled out, the containers constituting each storage room are pulled out together with the doors is there.

  A machine room is provided on the lower back side of the heat insulation box constituting the refrigerator 1. The machine room includes a compressor 12 that compresses and discharges a refrigerant, a condenser 13 that exchanges heat between the refrigerant and air, an external refrigerator 14 that promotes heat exchange between the refrigerant and air in the condenser 13, and a capillary Decompression units 15a and 15b made of tubes and a refrigerant switching valve 16 are disposed. The compressor 12, the condenser 13, the pressure reducing units 15a and 15b, and the refrigerant switching valve 16 are connected to the evaporator 17 and the condensation suppressing piping 18 by piping, and a refrigerant circuit in which the refrigerant circulates is formed. ing. Reference numerals 19, 20, 21 and the like denote pipes for a refrigerant.

  The refrigeration cycle includes a compressor 12, a condenser 13, pressure reducing units 15a and 15b, and an evaporator 17. A refrigerant switching valve 16 is provided downstream of the condenser 13 and upstream of the pressure reducing units 15a and 15b. Here, the condensation suppressing pipe 18 is a pipe provided to prevent condensation on the partition walls and the like of the storage rooms in front of the refrigerator. This piping is provided in order to prevent the temperature of the partition wall of each storage chamber of the refrigerator from becoming equal to or lower than the dew point temperature by utilizing the radiation of the refrigerant and to reduce the occurrence of dew condensation. Such a refrigerator is already well known and will not be described further.

  The inventors of the present invention have developed the above-described refrigerant switching valve 16, and have developed the refrigerant switching valve 16 configured as described below. Hereinafter, the configuration of the refrigerant switching valve 16 will be described. Here, although it was a 4-way valve in patent document 1, in this embodiment, since pressure reduction parts 15a and 15b are provided, it becomes a structure of a 5-way valve.

  FIG. 2 is a perspective view showing the appearance of the refrigerant switching valve 60 corresponding to the refrigerant switching valve 16 shown in FIG. 3 is a longitudinal sectional view of the refrigerant switching valve of FIG. 4 is a perspective view of the refrigerant switching valve 60 with the stator case and the valve case removed from the refrigerant switching valve 60. As shown in FIG. Moreover, FIG. 5 is M arrow direction (front view) of FIG. 1 when a valve case, a valve main body, and an idler gear are removed, FIG. 6 is KK sectional drawing of FIG. FIG. 7 is an exploded perspective view of a rotor pinion gear, an idler gear, and a valve body.

  In FIG. 2 to FIG. 7, a cylindrical stator 62 formed by winding a coil is formed inside a cylindrical stator case 61 that forms an exterior of the refrigerant switching valve 60. The stator case 61 is formed with a connector case 63 protruding outward, and a connector 65 is provided in the connector case 63. The connector 65 has a connector pin 64 for connecting the wire from the coil of the stator 62 to an external drive circuit.

  The rotor 70 is a rotor of a motor having a magnet, and when the connector pins 64 are connected to a drive circuit to energize the coils of the stator 62, a magnetic field is generated in the stator 62, and the magnetic field of the rotor 70 passes through the valve case 66. The rotor 70 rotates around the valve body shaft 71 by acting on the magnet. This motor can be configured, for example, as a stepping motor.

  The bottomed cylindrical valve case 66 covers the valve body 80 and suppresses the diffusion of the refrigerant supplied from the refrigerant inlet A, which is an example of the refrigerant supply unit, to the outside of the refrigerant switching valve 60. The upper side of the valve case 66 is fitted to the inner peripheral portion of the stator 62. In FIG. 3, a valve seat plate 67 is joined to the lower open end of the valve case 66. The valve case 66 and the valve seat plate 67 form a closed switching valve chamber.

  The valve seat plate 67 has three concentric flat surfaces different in thickness from each other, and the second valve seat plate portion 67a and the second valve seat plate portion 67a have a smaller diameter and thickness than the first valve seat plate portion 67a. A valve seat plate portion 67b and a third valve seat plate portion 67c which is thinner and thinner than the first valve seat plate portion 67a are integrally formed.

  As shown in FIGS. 4 and 5, the valve seat plate 67 is connected to a refrigerant inflow pipe 68 and four communicating pipes 69 through which the refrigerant can flow. The first valve seat plate 67a has a refrigerant inlet A, and the second valve seat plate 67b has four openings B-1, B-2, B-3, and B-4. . The refrigerant inflow port A supplies the refrigerant flowing through the refrigerant inflow pipe 68 to the inside of the valve case 66 (switch valve chamber). Each of the four openings B-1 to B-4 allows the refrigerant to flow through each of the four communication pipes 69b to 69e. The refrigerant inlet A and the openings B-1 to B-4 are in communication with the inside of the valve case 66. The portion of the valve seat plate 67 in contact with the valve main body 80 serves as a polished surface 86 to increase the planar accuracy.

  As shown in FIGS. 3 and 4, the valve body shaft 71 is the rotational center of the rotor 70 and the valve body 80. When the rotor 70 rotates, the rotational force is transmitted to the valve body 80 through the rotor pinion gear 75 connected to the rotor 70, the idler gear 79 supported by the valve body shaft 78, and the valve body gear 83 formed on the outer periphery of the valve body 80. Be done. Thus, the valve body 80 pivots relative to the valve seat plate 67. At the central position of the valve seat plate 67, a bottomed rotor shaft hole 72 in which the valve body shaft 71 is fitted is formed.

  As shown in FIG. 6 and FIG. 7, the rotor drive portion leading end 76 which is a convex portion provided around the rotation axis of the lower end portion of the rotor pinion gear 75 is mounted on the upper surface of the valve main body 80. The rotor pinion gear 75 and the valve main body 80 are rotatably disposed around a valve body shaft 71 which is a common central axis, via a rotor drive shaft hole 77 and a valve body shaft hole 85, respectively.

  The valve main body 80 is formed with a stopper 84 projecting from the outer periphery of the valve body gear 83. When the valve body 80 is rotated by a predetermined angle, the stopper 84 abuts on the lower idler stopper 79c of the idler pinion gear 79a to limit the rotation of the valve body 80. In addition, the stopper 84 is provided so that the valve body 80 can be rotated larger than the angle required for the switching operation of each state of the refrigerant switching valve 60 described later. Three refrigerant conducting portions 82 are provided on the valve body sliding contact surface 81 of the valve main body 80. The refrigerant conducting portion 82 has a valve body groove 82a (first valve body groove), a valve body groove 82b (second valve body groove), and a valve body groove 82c (third valve body groove). The valve body grooves 82a, 82b and 82c allow the refrigerant to flow in a predetermined state by the rotation of the valve body 80.

  As shown in FIG. 5, the openings B-1 to B-4 are provided at substantially equal distances from the valve shaft 71 at substantially equal intervals. The openings B-1 to B-4 are arranged in order of B-1, B-2, B-3, and B-4 clockwise in the circumferential direction with reference to the refrigerant inlet A, and the openings B -1 to the opening B-4 are adjacent in the circumferential direction. Further, the openings B-1 to B-4 are arranged at intervals of about 90 ° with the valve body axis 71 at the center.

  Of the openings B-1 to B-4, the opening B-1 is closest to the refrigerant inlet A in the state shown in FIG. 5 (the state of the second mode described below). The refrigerant inlet A is located on the opposite side of the valve shaft 71 across the opening B-1. The idler shaft 78 is provided on the opposite side to the refrigerant inlet A with the valve body shaft 71 interposed therebetween.

  Next, the relationship between the refrigerant switching valve 60 and the refrigeration cycle will be described. FIG. 8 schematically shows the refrigerant circuit of the refrigeration cycle provided in the refrigerator 1. The refrigerator 1 drives a refrigeration cycle using a refrigerant. The refrigeration cycle includes, in addition to the refrigerant switching valve 60, a compressor 12, a condenser 13, a condensation suppression pipe 18, pressure reducing units 15a and 15b, an evaporator 18, and pipes 20, 21, 22a and 22b.

  A pipe 20, a condenser 13, a compressor 12, and an evaporator 17 are connected to the refrigerant inlet A in order from the refrigerant inlet A side. The refrigerant reaches a high temperature and a high pressure in the compressor 12 and flows through the condenser 13 and the pipe 20 to reach the refrigerant inlet A.

  One end and the other end of the condensation suppressing pipe 18 are connected to the openings B-1 and B-3, respectively. Further, one end of a first decompression unit 15a is connected to the opening B-2, and one end of a second decompression unit 15b is connected to the opening B-4. The other ends of the first pressure reducing unit 15 a and the second pressure reducing unit 15 b are connected by a merging unit 89. The refrigerant that has passed through the first pressure reducing unit 15a or the second pressure reducing unit 15b flows through the merging unit 89, and then flows into the evaporator 17 and returns to the compressor 12 again. The first pressure reducing section 15a and the second pressure reducing section 15b differ in the amount of pressure reduction of the passing refrigerant, and for example, capillary tubes may be employed as the two pressure reducing sections 15a and 15b and their diameters may be different. It is a thing.

  The high-temperature, high-pressure refrigerant compressed by the compressor 12 flows into the condenser 13 and is cooled by heat exchange with air (outside air) in the condenser 13. The refrigerant flowing out of the condenser 13 flows through the refrigerant pipe 20 and flows into the refrigerant inlet A of the fluid switching valve 60. The refrigerant flows depending on each mode, and then flows downstream of the fluid switching valve 60 by the opening B-2 or the opening B-4. The positions of the openings of the refrigerant switching valve 60 in FIG. 8 are schematically represented and slightly different from those shown in FIG.

  Further, the refrigerant is depressurized by the first depressurizing unit 15a or the second depressurizing unit 15b to be a low temperature and a low pressure, and reaches the junction 89. Thereafter, the refrigerant flows into the evaporator 17, exchanges heat with the ambient air, and returns to the compressor 12. The air cooled by the evaporator 18 becomes cold and is distributed and supplied to each storage chamber of the refrigerator 1.

  Next, each mode executed based on the switching operation of the refrigerant switching valve 60 will be briefly described.

  The first mode is a mode in which the refrigerant is caused to flow through the condensation suppressing pipe 18 and the first pressure reducing portion 15a. The refrigerant flows through the refrigerant inlet A and the opening B-1, passes through the condensation suppression pipe 18 and flows through the opening B-3 and the opening B-2 to the first pressure reducing portion 15a.

  The second mode is a mode in which the refrigerant is caused to flow only to the first pressure reducing portion 15a. The refrigerant flows from the refrigerant inlet A directly through the opening B-2 to the first pressure reducing portion 15a. In this mode, the refrigerant is not delivered to the condensation suppression pipe 18.

  The third mode is a mode in which the refrigerant is caused to flow through the condensation suppression pipe 18 and the first pressure reducing portion 15a. The refrigerant flows from the refrigerant inlet A through the opening B-3, passes through the condensation suppression pipe 18 and flows through the opening B-1 and the opening B-2 to the pressure reducing portion 15a. In this case, the flow direction of the refrigerant flowing through the condensation suppression pipe 18 is opposite to that in the first mode.

  The fourth mode is a mode in which the openings B-2 and B-4 are closed together to block the flow of the refrigerant. At this time, the compressor 51 is stopped in this embodiment.

  The fifth mode is a mode in which the refrigerant is caused to flow through the condensation suppressing pipe 18 and the second pressure reducing portion 15 b. The refrigerant flows from the refrigerant inlet A through the opening B-3, passes through the condensation suppression pipe 18 and flows through the opening B-1 and the opening B-4 to the second pressure reducing portion 15b. Also in this case, the flow direction of the refrigerant flowing through the condensation suppression piping 18 is reverse to that in the first mode.

  The sixth mode is a mode in which the refrigerant is caused to flow only to the second pressure reducing portion 15b. The refrigerant flows from the refrigerant inlet A directly through the opening B-4 to the second pressure reducing portion 15b. In this mode, the refrigerant is not delivered to the condensation suppression pipe 18.

  The seventh mode is a mode in which the refrigerant is caused to flow through the condensation suppression piping 18 and the second pressure reducing portion 15 b. The refrigerant flows from the refrigerant inlet A through the opening B-1, passes through the condensation suppression pipe 18, flows through the opening B-3 and the opening B-4, and flows to the second pressure reducing portion 15b. In this case, the flow direction of the refrigerant flowing through the condensation suppression piping 18 is the same as that in the first mode.

  The configuration of the valve main body 80 of the refrigerant switching valve 60 for executing each mode as described above is as follows.

  FIG. 9 shows the relationship between the opening B-1 to the opening B-4 and the sliding contact surface 81 of the valve body. The valve element sliding contact surface 81, which is one surface of the valve main body 80, rotates around the valve element shaft 71 while in contact with the polished surface 86 provided with the openings B-1 to B-4. By rotating the valve body 80 relative to the valve seat plate 67, the openings B-1 to B-4 provided in the valve seat plate 67 can be opened and closed. The refrigerant inlet A always supplies the refrigerant to the inside of the valve case 66 regardless of the rotation of the valve body 80.

  A refrigerant conducting portion 82 is provided on the valve body sliding contact surface 81. The refrigerant conducting portion 82 has a valve body groove 82a, a valve body groove 82b, and a valve body groove 82c. The valve body grooves 82a and 82b are grooves provided on the valve body sliding contact surface 81, and are configured to allow the refrigerant to move between the two openings when overlapping with the two openings.

  Therefore, for example, in the first mode, by rotating the valve main body 80 counterclockwise by a predetermined angle, the refrigerant can be expressed by the opening B-1⇒condensation suppression piping 18⇒opening B-3⇒refrigerant conduction path 82a⇒opening B-2 流 れ る It flows with the 1st pressure reduction part 15a. Hereinafter, the respective modes described above are executed in the same manner. Incidentally, the state of FIG. 9 shows the state of the second mode.

  By the way, as shown in FIGS. 7 and 9, the shape of the valve contact surface 81 of the valve main body 80 described above forms the refrigerant conducting paths 82a, 82b and 82c in the flat valve contact surface 81. It is Therefore, the refrigerant having a high pressure flowing from the refrigerant inlet A strongly presses the sliding surface 81 of the valve body 80 toward the polished surface 86 provided with the opening B-1 to the opening B-4. It has been found that a large contact pressure acts between the valve body and the valve seat, resulting in an increase in the sliding resistance between the valve body and the valve seat.

  If the sliding resistance becomes large, at least the problem that the predetermined operation can not be obtained unless the electric power supplied to the electric motor is increased, or the rotation operation of the valve main body is delayed, and smooth refrigerant switching can not be performed, or This causes one or more of the problems that the valve body does not rotate to a predetermined position and the refrigerant switching itself can be performed.

  In order to solve such a problem, in the present embodiment, the valve sliding surface of the valve body that slides with the valve seat is formed with a recess that does not have the function of flowing the refrigerant separately from the conduction path through which the refrigerant flows. Thus, a configuration is proposed in which the sliding contact area with the valve seat is reduced.

  Hereinafter, the refrigerant switching valve 60 according to the present embodiment will be described in detail. 10 and 11 are a top perspective view and a bottom perspective view of the valve body 80 according to this embodiment.

  In FIG. 10, a circular concave portion 87 is formed on the inner side of the valve main body 80, and an annular wall 88 is formed on the outer peripheral portion. A valve body gear 83 is formed on the outer peripheral surface of the annular wall 88. This is as shown in FIG. A portion of the valve body gear 83 in the circumferential direction is cut away, and a stopper 84 is formed in this portion. Further, a valve shaft hole 85 is formed at the center of the bottom wall 89 of the valve body 80. The stopper 84 and the valve body shaft hole 85 are also as shown in FIG.

  Further, as shown in FIG. 11, a two-step flat surface is formed on the surface of the bottom wall 89 opposite to the side where the electric motor is disposed. The lower flat surface is the coolant passage 90 to which the coolant is always supplied, which corresponds to the coolant passage 82c shown in FIG. On the other hand, the flat surface on the higher side is the valve element sliding contact surface 91, and in the valve element sliding contact surface 91, two elongated refrigerant conducting paths 92a and 92b are formed. The two refrigerant conduction paths 92 a and 92 b are formed in the same shape at positions symmetrical with respect to the valve body shaft hole 85 at axisymmetric positions. The refrigerant channels 92a and 92b correspond to the refrigerant channels 82a and 82b shown in FIG. 7, and the refrigerant channels have such lengths that the respective openings can be communicated with each other. This will be described later.

  An area reduction recess 93 for reducing the sliding contact area of the valve element sliding contact surface 91, which is a feature of the present embodiment, is formed in the region surrounded by the refrigerant conducting paths 92a and 92b and the valve body shaft hole 85. ing. The area reduction recess 93 extends from the valve shaft hole 85 toward the stopper 84, and in this region, the refrigerant directly flows from the refrigerant inlet A to the opening B-2 in the second mode (FIG. 9). In the state of flowing), the opening B-4 is positioned.

  However, the distance between the adjacent refrigerant conduction paths 92a and 92b is set to a length close to the "seal length L" as described later. The reason for setting the predetermined distance L is to secure a sufficient sealing function. Moreover, the depth from the sliding contact surface of the valve body sliding contact surface 91 of the area reduction recessed part 93 is shallower than refrigerant | coolant conduction path 92a, 92b. The point is that it is only necessary to reduce the area of the sliding contact surface 91, so it is better if the surface is slightly deeper.

  In addition, although the area reduction recessed part 93 is formed in elongate shape, this shape is arbitrary, and the number and the arrangement position are also arbitrary. The point is that the sliding contact surface 91 may be appropriately disposed as long as the sealing function is not impaired.

  Further, on the outer peripheral side of the refrigerant conduction paths 92a and 92b, in the state of the second mode described above (in FIG. 9, the state where the refrigerant flows directly from the refrigerant inlet A to the opening B-2), the opening B-1 A closed region for B-1 (hereinafter referred to as a closed surface) 94 and a closed region for B-3 (hereinafter referred to as a closed surface) 95 are formed to completely close the opening B-3. The two closing surfaces 94 and 95 are formed on the valve element sliding contact surface 91. Furthermore, notches 96 and 97 for reducing the sliding contact area are formed on the outer peripheral surface facing the stopper 84 side from the closing surfaces 94 and 95.

  Furthermore, the detailed shape of the valve-body sliding contact surface 91 mentioned above is demonstrated using FIG. Description of the same parts as those in FIG. 11 will be omitted.

  In FIG. 12, in addition to the shape of the valve element sliding contact surface 91, the openings B-1 to B-4 for controlling the flow of the refrigerant in cooperation with this are shown by broken lines. Therefore, the communication pipe 69b to the communication pipe 69e extend perpendicularly to the front side of the drawing.

  FIG. 12 shows the state of the second mode (in FIG. 9, a state where the refrigerant flows directly from the refrigerant inlet A to the opening B-2). Therefore, in this state, the openings B-1 and B-3 are completely closed by the B-1 closing surface 94 and the B-3 closing surface 95.

  In a region surrounded by the refrigerant conduction paths 92a and 92b and the valve body shaft hole 85, an area reduction concave portion 93 for reducing a sliding contact area of the valve body sliding contact surface 91 is formed. The area reducing recess 93 extends from the valve shaft hole 85 toward the stopper 84, and the opening B-4 is located in this area. Although the opening B-4 is opened to face the area reduction recess 93, the area reduction recess 93 does not have a conduction function to flow the refrigerant to the other openings, so the opening B-4 also has an area reduction recess 93. It is closed by the arranged closing area of.

  On the other hand, since the opening B-2 is separated from the valve element sliding contact surface 91, the refrigerant can flow out to the opening B-2 from the portion of the non-closing area.

  Further, as can be seen from FIG. 12, the distance from the valve body axial hole 85 to the openings B-2 and B-4, in other words, the lengths from the opening B-2 and the opening B-4, is the valve body axial hole 85 To the openings B-1 and B-3, in other words, the lengths to the openings B-1 and B-3. By doing this, it is possible to shorten the length of the refrigerant conduction paths 92a and 92b, which makes it possible to reduce the diameter of the valve body 80.

  For example, if all the openings are equidistantly spaced outward from the valve shaft hole 85 in the same manner as the openings B-1 and B-3, the lengths of the refrigerant channels 92a and 92b must be increased, and This is because the wall thickness for forming the sealing surface for forming the refrigerant conduction paths 92a and 92b is also required, which causes a problem that the diameter of the valve main body 80 becomes large.

  Further, the opening B-2 has the valve contact surface 91 (= seal surface) located on both sides, and the position of the opening B-2 is close to the valve shaft hole 85, so the valve contact surface only by this amount It contributes to reducing the circumferential area of 91.

  Further, in accordance with the rotation of the valve main body 80, the shape of the refrigerant passage 92a is set so as to connect the opening B-1 and the opening B-2 or the opening B-1 and the opening B-4. Similarly, the shape of the refrigerant conduction path 92b is set to a shape connecting the opening B-3 and the opening B-2, or the opening B-3 and the opening B-4.

  Next, how to determine the shapes of the B-1 closing surface 94 and the B-3 closing surface 95 will be described, but the B-3 closing surface 95 will be described as a representative below.

  In the state of FIG. 12, in order to secure the sealing performance (sealing performance) of the B-3 closing surface 95 up to the periphery of the opening B-3 and the periphery of the refrigerant conduction path 92b, the refrigerant from the periphery of the opening B-3 A closing distance of a predetermined length (hereinafter referred to as a seal length) is required to the peripheral edge of the conduction path 92b. In this embodiment, L / D at which the stroke capacity index CP becomes a predetermined value is obtained from the diameter D of the opening B-3 and the “seal length L” from the peripheral edge of the opening B-3 to the peripheral edge of the refrigerant passage 92b. The “seal length L” is determined from the peripheral edge of the opening B-3 to the peripheral edge of the refrigerant passage 92b. The “seal length L” substantially corresponds to the shortest distance from the periphery of the opening B-3 to the periphery of the refrigerant passage 92b.

  Here, the process capability index CP is one of the indicators for quantitatively evaluating the process capability of a certain process in the field of quality control. And, in the present embodiment, if the process capability index CP is about 0.8 or more, it is a value at which the problem of leakage does not occur. Then, as shown in FIG. 13, if L / D is 0.45 or more, the CP value will be 0.8 or more, and the reliability against leakage can be sufficiently ensured. Therefore, when L / D = 0.45, and the diameter D of the opening B-3 is determined, the “seal length L” from the periphery of the opening B-3 to the periphery of the refrigerant conduction path 92b is L = 0. It can be determined by 45 × D.

  Thus, when the diameter D of the opening B-3 and the “seal length L” from the peripheral edge of the opening B-3 to the peripheral edge of the refrigerant passage 92b are determined, the radius centered on the center of the opening B-3 ( The basic shape of the B-3 closing surface 95 is determined by drawing a circle of D / 2 + L). Therefore, the B-3 closing surface 95 seals the opening B-3 with the "seal length L".

  Then, a build-up portion C is formed in the vicinity of the connection portion between the outer peripheral edge 97A of the notch 97 and the outer peripheral edge of the B-3 closing surface 95 along the shape of the refrigerant conducting passage 92b. The basic shape of is corrected. By forming the build-up portion C in this manner, it is possible to suppress the fluctuation of the sealing performance due to the deviation of the rotational position of the valve main body 80.

  Furthermore, in the B-3 closing surface 95, a notch 99 is also formed on the side opposite to the notch 97 with the opening B-3 as a boundary. Of course, a notch 98 is also formed on the side opposite to the notch 96 with the B-1 closing surface 94 as a boundary with the opening B-1. This further contributes to reducing the sliding contact area of the valve element sliding contact surface 91. Thus, the shapes of the B-3 closing surface 95 and the B-1 closing surface 94 can be determined.

  Furthermore, the "seal length L" obtained in this manner is also used to determine the outer shape of the contact surface 91 of the sliding contact surface of the valve body. As can be seen from FIG. 12, except for the B-3 closing surface 95 and the B-1 closing surface 94, along the shapes of the refrigerant conducting paths 92a and 92b, a width close to the “seal length L” The shape of the valve disc sliding contact surface 91 is determined so as to form only the seal area having the same. Therefore, the seal surfaces other than the seal area are cut away as in the notches 96, 97, 98, 99 and so on.

  Similarly, the distance between the refrigerant conduction paths 92a and 92b and the area reduction recess 93 is also determined to be close to the “seal length L”. Therefore, in the present embodiment, the unnecessary valve body sliding contact surface as shown in FIG. 9 is omitted while leaving the necessary valve body sliding contact surface 91.

  As described above, according to the present embodiment, the sliding contact area of the sliding contact surface of the valve body can be reduced by providing at least the area reduction recessed portion or the area reducing recess and the cutaway portion on the sliding contact surface of the valve body. As a result, there is a problem that the predetermined operation can not be obtained unless the electric power supplied to the electric motor is increased, or the rotation operation of the valve main body is delayed and smooth refrigerant switching can not be performed. It is possible to solve one or more problems among the problems that the refrigerant switching itself can be performed without rotating to the maximum.

  Next, the flow of the refrigerant in the transition state at the time of mode switching according to the present embodiment will be described. In this case, in this case, the refrigerant flows in the condensation suppression piping 18 when switching from the first mode in which the refrigerant is circulated in the condensation suppression piping 18 and the first decompression unit 15a to the second mode in which the refrigerant flows only in the first decompression unit 15a. The refrigerant will be described.

  FIG. 14A shows the state of the first mode, and the positions of the refrigerant passages 92a and 92b of the valve body 80 of the refrigerant switching valve 60 and the relative positions of the openings B-1 to B-4 are as illustrated. . Hereinafter, FIGS. 14B, 14C, 14D, and 14E are the same.

  In the state of the first mode, the refrigerant flows from the opening B-1 and flows through the condensation suppressing pipe 18, and flows out from the opening B-2 from the opening B-3 through the refrigerant passage 92b. As a result, a large amount of refrigerant flows in the condensation suppression piping 18 and condensation on the partition wall and the like can be suppressed.

  Further, when the valve body 80 is rotated clockwise from the first mode shown in FIG. 14A, as shown in FIG. 14B, the positions of the coolant channels 92a and 92b and the positions of the openings B-1 to B-4. The relative position changes. Also in FIG. 14B, the refrigerant flows from the opening B-1 and flows through the condensation suppressing piping 18 due to the presence of the cutaway portion 99 formed in the valve body sliding contact surface 91, and the opening passes through the refrigerant conduction path 92b from the opening B-3. It flows out from B-2. In this state, the opening B-3, the refrigerant passage 92b, and the opening B-2 are still in the conductive state. By this, a refrigerant | coolant flows into the dew condensation suppression piping 18, and it can suppress dew condensation of a partition wall etc. FIG. In this case, the amount of refrigerant flowing to the condensation suppression pipe 18 is reduced as compared to FIG. 14A.

  Further, when the valve body 80 is rotated clockwise from the state shown in FIG. 14B, as shown in FIG. 14C, the positions of the coolant channels 92a and 92b and the relative positions of the openings B-1 to B-4. Is changing. Also in FIG. 14C, the refrigerant flows from the opening B-1 and flows through the condensation suppressing pipe 18 due to the presence of the cutaway portion 99 formed in the valve element sliding contact surface 91, and the opening passes through the refrigerant conduction path 92b from the opening B-3. It flows out from B-2. In this state, the area where the opening B-3 communicates with the refrigerant passage 92b and the opening B-2 is reduced, but is still in the connected state. By this, a refrigerant | coolant flows into the dew condensation suppression piping 18, and it can suppress dew condensation of a partition wall etc. FIG. In this case, the amount of refrigerant flowing to the condensation suppression pipe 18 is further reduced as compared with FIG. 14B.

  Further, when the valve body 80 rotates clockwise from the state shown in FIG. 14C, as shown in FIG. 14D, the positions of the refrigerant conducting paths 92a and 92b and the relative positions of the openings B-1 to the openings B-4. Is changing. Also in FIG. 14D, the refrigerant flows from the opening B-1 and flows through the condensation suppressing pipe 18 due to the presence of the cutaway portion 99 formed in the valve element sliding contact surface 91, and the opening passes through the refrigerant conduction path 92b from the opening B-3. It flows out from B-2. In this state, the refrigerant passage area of the opening B-1 is further narrowed, and the area of conduction between the opening B-3 and the refrigerant conduction path 92b and the opening B-2 is reduced, but is still in the conduction state. As a result, although a small amount of refrigerant flows in the condensation suppression piping 18, condensation on the partition wall and the like can be suppressed.

  Further, when the valve body 80 is rotated clockwise from the state shown in FIG. 14D, the mode is switched to the second mode as shown in FIG. 14E. In this state, the opening B-1 is completely closed by the B-1 closing surface 95, and similarly, the opening B-3 is completely closed by the B-3 closing surface 96. On the other hand, since the opening B-2 is separated from the valve element sliding contact surface 91, the refrigerant directly flows into the opening B-2. In this state, the refrigerant does not flow in the condensation suppression pipe 18.

  As described above, according to the present embodiment, since the refrigerant continues to flow to the condensation suppression pipe 18 even in the process of transitioning from the first mode to the second mode, it is possible to further suppress condensation such as the partition wall.

  As described above, according to the present invention, the sliding contact surface of the valve main body sliding with the valve seat is formed with a recess which does not have the function of flowing the refrigerant separately from at least the conduction passage through which the refrigerant flows. To reduce the sliding contact area. According to this, since the sliding contact area of the sliding contact surface of the valve body is reduced by the recess, the sliding resistance can be reduced.

  As a result, at least the problem that the predetermined operation can not be obtained unless the electric power supplied to the electric motor is increased, the rotation operation of the valve main body is delayed and the smooth refrigerant switching can not be performed, the valve main body is at the predetermined position It is possible to solve one or more of the problems that the refrigerant switching itself can be performed without rotating to the maximum.

  The present invention is not limited to the embodiments described above, but includes various modifications. For example, the embodiments described above are described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. In addition, with respect to a part of the configuration of each embodiment, it is possible to add, delete, and replace other configurations.

  DESCRIPTION OF SYMBOLS 1 ... Refrigerator, 12 ... Compressor, 13 ... Condenser, 15a, 15b ... Decompression part, 16 ... Refrigerant switching valve, 17 ... Evaporator, 18 ... Condensation suppression piping, 60 ... Refrigerant switching valve, 66 ... Valve case, 67 ... valve seat plate, 67a ... first valve seat plate, 67b ... second valve seat plate, 68 ... refrigerant inflow pipe, 69b ... communication pipe, 69c ... communication pipe, 69d ... communication pipe, 69e ... communication pipe, 71 ... valve body shaft, 80 ... valve body, 81 ... valve body sliding contact surface, 82a ... valve body groove, 82b ... valve body groove, 82c ... valve body groove, 86 ... polished surface, 84 ... stopper, 85 ... valve body Shaft hole, 87: recessed portion, 88: annular wall, 89: bottom wall, 90: refrigerant passage, 91: sliding contact surface of valve body, 92a, 92b: refrigerant passage, 93: area reduction recess, 94: B-1 Closed surface, 95: B-3 Closed surface, 96 to 99: Notched part, A: Refrigerant inlet B-1 to B-4: Open .

Claims (6)

A flat valve seat having a plurality of openings provided in the switching valve chamber, into which the refrigerant from the compressor flows, a plurality of openings provided in the switching valve chamber, and in sliding contact with the valve seat A valve body having a flat sliding contact surface, and further comprising a refrigerant conducting path for connecting or blocking at least two of the openings to the sliding contact surface; and an electric motor for rotating the valve body to a predetermined position In the equipped refrigerant switching valve,
While forming the area reduction recessed part of the predetermined shape which is not equipped with the conduction | electrical_connection function of a refrigerant | coolant in the said sliding contact surface of the said valve main body at least ,
The openings are four openings, and the respective openings are arranged at intervals of about 90 ° with respect to the rotation center of the valve body,
The sliding contact surface of the valve body includes a pair of closing regions closing the pair of opposed openings, and one of the remaining pair of the openings in a state where the pair of closing regions close the pair of openings. A refrigerant switching valve characterized in that the refrigerant switching valve is formed of a closing area for closing the second opening and a non-closing area not closing the other opening. In the refrigerant switching valve according to claim 1,
In a state in which the pair of closed regions close the pair of openings, the sliding contact surface is formed between the pair of respective openings closed by the pair of closed regions and the remaining pair of openings. A refrigerant switching valve characterized in that each of the refrigerant conducting paths is disposed, and an area reducing recess of the predetermined shape is formed between the refrigerant conducting paths. In the refrigerant switching valve according to claim 2,
A refrigerant switching valve characterized in that a distance between the pair of openings closed by the pair of closing regions is longer than a distance between the other pair of the openings. In the refrigerant switching valve according to claim 3,
A width of a length substantially corresponding to the shortest distance between the peripheral edge of the refrigerant conduction path and the peripheral edge of the opening located on the outer peripheral side of the refrigerant conduction path, with the pair of closing regions closing the pair of openings The refrigerant switching valve is characterized in that a seal area having a second seal area is formed along each of the refrigerant conduction paths other than the pair of closed areas, and the sliding contact surface is formed by the pair of closed areas and the seal area. . A flat valve seat having a plurality of openings provided in the switching valve chamber, into which the refrigerant from the compressor flows, a plurality of openings provided in the switching valve chamber, and in sliding contact with the valve seat A valve body having a flat sliding contact surface, and further comprising a refrigerant conducting path for connecting or blocking at least two of the openings in the sliding contact surface; and an electric motor for rotating the valve body to a predetermined position; A refrigerant switching valve comprising: a case for housing the valve body; and a refrigerant inlet for supplying a refrigerant into the case;
While forming the area reduction recessed part of the predetermined shape which is not equipped with the conduction | electrical_connection function of a refrigerant | coolant in the said sliding contact surface of the said valve main body at least,
The plurality of openings are four openings in which the first opening and the third opening, and the second opening and the fourth opening are disposed to face each other across the rotation axis,
  In the sliding surface of the valve body, a first closing area and a third closing area for closing the first opening and the third opening, and a first closing area and a third closing area are the first opening. And a fourth closed area for closing the fourth opening and a non-closed area not closing the second opening in a state where the third opening is closed,
  A refrigerant switching valve comprising the area reducing recess on the opposite side to the non-closing region with the rotating shaft interposed therebetween. In the refrigerant switching valve according to claim 5,
The respective openings are arranged at intervals of about 90 ° in the order of the first opening, the second opening, the third opening, and the fourth opening with reference to the rotation center of the valve body,
Furthermore, the area reduction recess is formed between each of the refrigerant passages .

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