Valve device

Abstract

A valve device comprises: an introduction flow path (21), a first lead-out flow path (221), and a second lead-out flow path (222) that are formed in a flow path housing (11); a first valve seat (121) that is provided between the introduction flow path (21) and the first lead-out flow path (221); a second valve seat (122) that is provided between the introduction flow path (21) and the second lead-out flow path (222); a first valve body (131) that is abuttable against the first valve seat (121); a second valve body (132) that is abuttable against the second valve seat (122); a valve shaft (14) that has attached thereto the first valve body (131) and the second valve body (132); and an actuator (15) that drives the valve shaft (14). A gap (26) is provided between the first valve body (131) and the second valve body (132). The valve bodies (131, 132) have valve body facing walls (131a, 132a) facing each other with the gap (26) therebetween. Each of the valve body facing walls (131a, 132a) has a tapered shape or an R shape from the valve shaft (14) toward the corresponding lead-out flow path (221, 222).

Description

Valve device

[0001] The technology disclosed in this specification relates to a valve device that regulates the flow of a fluid in a flow path.

[0002] A known example of this type of technology is disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2003-149996). This technology relates to a flow dividing valve (valve device) for dividing a fluid, and includes an input port (inlet flow path), a first output port (first outlet flow path), a second output port (second outlet flow path), a first valve seat (first valve seat) formed between the inlet flow path and the first outlet flow path, a second valve seat (second valve seat) formed between the inlet flow path and the second outlet flow path, a first valve element (first valve element) abutting and separating from the first valve seat, a second valve element (second valve element) abutting and separating from the second valve seat, a shaft (valve stem) to which the first valve element and the second valve element are attached, and a motor (drive unit) for driving the valve stem. The first valve element and the second valve element are attached adjacent to each other at a distance on the valve stem.

[0003] Japanese Patent Application Laid-Open No. 2005-3190

[0004] However, in the valve device described in Patent Document 1, the gap between the first valve body and the second valve body has a complicated shape relative to the fluid, which means that the flow of fluid passing through the gap between the first valve body and the second valve body toward the first outlet flow path or the second outlet flow path is obstructed, raising concerns that the fluid may stagnate.

[0005] This disclosed technology has been made in consideration of the above circumstances, and its purpose is to provide a valve device that makes it possible to suppress the accumulation of fluid flowing into the gap between two valve bodies on the valve shaft.

[0006] (1) In order to achieve the above object, one aspect of the disclosed technique is a fluid supply system including a flow path member, an inlet flow path formed in the flow path member and for introducing a fluid, a first outlet flow path formed in the flow path member and for discharging the fluid introduced from the inlet flow path, a second outlet flow path formed in the flow path member and for discharging the fluid introduced from the inlet flow path, a first valve seat provided in the flow path member between the inlet flow path and the first outlet flow path, a second valve seat provided in the flow path member between the inlet flow path and the second outlet flow path, and a valve seat provided in the first valve member. The purpose of this invention is to provide a valve device comprising a first valve body that contacts and moves away from a seat, a second valve body that contacts and moves away from a second valve seat, a valve stem to which the first valve body and the second valve body are attached, and a drive unit for driving the valve stem, wherein a predetermined gap is provided between the first valve body and the second valve body, and within the gap, the valve bodies have valve body opposing walls that face each other, and at least a portion of the circumferential direction of each valve body opposing wall has a tapered or R-shaped shape that extends from the valve stem toward each corresponding outlet flow path.

[0007] According to the configuration (1) above, in the gap between the first and second valve bodies attached to the valve stem, each valve body facing wall of each valve body has a tapered or rounded shape extending from the valve stem toward the corresponding outlet flow path along at least a portion of the circumferential direction. Therefore, the shape of each valve body facing wall reduces pressure loss of the fluid flowing from the inlet flow path into the gap between the two valve bodies, and smooths the flow of the fluid from that gap toward the outlet flow path.

[0008] (2) In order to achieve the above object, in the configuration of (1) above, it is preferable to provide a first valve hole formed in the first valve seat and a second valve hole formed in the second valve seat, and to provide at least one of the valve seats with a converging inner wall having an R-shape or a tapered shape that converges from the introduction flow path to the corresponding valve hole.

[0009] According to the configuration (2) above, in addition to the effects of the configuration (1) above, at least one of the valve seats is provided with a converging inner wall of an R-shape or tapered shape that converges from the inlet passage to the corresponding valve hole, thereby reducing pressure loss of the fluid flowing from the inlet passage to the corresponding valve hole and allowing the fluid to flow smoothly toward at least one of the valve holes.

[0010] (3) To achieve the above object, in the configuration of (2) above, it is preferable that each valve disc is provided with a sealing member at the contact portion with the corresponding valve seat, at least one valve disc-side opening edge of each valve hole is provided with an annular valve seat ridge that can contact the sealing member, a valve seat groove is formed in the converging inner wall inside the valve seat ridge, the opening of the valve seat groove is formed following an imaginary continuous line that is continuous with the R-shape or tapered shape of the converging inner wall, and the imaginary continuous line is connected to the tip of the valve seat ridge.

[0011] According to the configuration (3), in addition to the effects of the configuration (2), each valve disc is provided with a seal member at the contact portion with its corresponding valve seat, and at least one valve disc-side opening edge of each valve hole is provided with an annular valve seat ridge that can contact the seal member. Therefore, contact between at least one valve seat and the corresponding valve disc is achieved by the engagement contact between the valve seat ridge and the seal member. Furthermore, the opening of the valve seat groove formed in the converging inner wall inward from the valve seat ridge is formed along an imaginary continuous line that continues into the R-shaped or tapered shape of the converging inner wall, and the imaginary continuous line connects to the tip of the valve seat ridge. Therefore, fluid flowing along the R-shaped or tapered shape of the converging inner wall of the valve seat flows downstream without colliding with the valve seat ridge.

[0012] (4) In order to achieve the above object, in any of the configurations (1) to (3) above, it is preferable that each valve element has a valve seat facing wall facing each corresponding valve seat, and at least one of the valve seat facing walls has an R-shape or a tapered shape that converges toward each corresponding valve hole.

[0013] According to the configuration (4) above, in addition to the effects of any of the configurations (1) to (3) above, at least one of the valve seat-facing walls of each valve disc facing the corresponding valve seat has an R-shaped or tapered shape converging toward the corresponding valve hole. Therefore, for at least one of the valve discs, when the valve is open, the valve seat-facing wall converging into an R-shaped or tapered shape rectifies the flow of fluid toward the valve hole, reducing pressure loss of the fluid.

[0014] (5) To achieve the above object, in any of the configurations (1) to (3) above, it is preferable that the first valve seat is formed integrally with a retaining member that is separate from the flow path member, and that the retaining member has a connecting portion that extends coaxially with the valve axis at the connection portion between the inlet flow path and the first outlet flow path and is connected to the first valve seat.

[0015] According to the configuration (5) above, in addition to the effects of any of the configurations (1) to (3) above, since the first valve seat is formed integrally with the retaining member that is separate from the flow path member, the degree of freedom in molding the first valve seat is improved compared to when the first valve seat is formed in the flow path member. Also, since the retaining member has a connecting portion that extends coaxially with the valve stem at the connection portion between the inlet flow path and the first outlet flow path and is connected to the first valve seat, the connecting portion does not restrict movement of the valve stem.

[0016] (6) To achieve the above object, in the configuration of (5) above, it is preferable that the holding member is provided integrally with the drive unit.

[0017] According to the configuration (6) above, in addition to the effect of the configuration (5) above, the retaining member on which the first valve seat is formed is provided integrally with the drive unit, so that when the drive unit is assembled to the flow path member, the first valve seat is simultaneously assembled to the flow path member.

[0018] (7) In order to achieve the above object, in any one of the configurations (1) to (3), the valve device is preferably used in a cooling system mounted on an electric vehicle.

[0019] According to the configuration (7), in addition to the effects of any of the configurations (1) to (3), since the valve device is used in a cooling system mounted on an electric vehicle, the same effects as any of the configurations (1) to (3) can be obtained in the cooling system of the electric vehicle. Also, the flow efficiency of the fluid in the valve device in the cooling system is improved.

[0020] According to the above configuration (1), it is possible to prevent the fluid that flows into the gap between the two valve bodies on the valve stem from accumulating.

[0021] According to the configuration (2) above, in addition to the effect of the configuration (1) above, it is possible to suppress the accumulation of fluid flowing into at least one of the first valve hole and the second valve hole.

[0022] According to the configuration (3) above, in addition to the effect of the configuration (2) above, when the valve is fully closed, the sealing performance of the valve seat can be improved by the engagement contact between the valve seat ridge and the seal member, and when the valve is open, the retention of fluid inside the valve seat ridge on the valve seat can be suppressed.

[0023] According to the configuration (4) above, in addition to the effect of any one of the configurations (1) to (3) above, it is possible to suppress the retention of fluid flowing into the valve hole.

[0024] According to the configuration (5) above, in addition to the effect of any one of the configurations (1) to (3) above, it is possible to easily form a converging inner wall having an R-shape or a tapered shape around the first valve hole of the first valve seat.

[0025] According to the above-mentioned configuration (6), in addition to the effect of the above-mentioned configuration (5), it is possible to omit the step of assembling only the first valve seat to the flow path member.

[0026] According to the configuration (7), in addition to the effects of any one of the configurations (1) to (3), it is possible to obtain the same effects as any one of the configurations (1) to (3) for a valve device used in a cooling system of an electric vehicle. Furthermore, it is possible to improve the energy efficiency of the cooling system of an electric vehicle, thereby contributing to carbon neutrality.

[0027] 5 is a cross-sectional view showing a first open state of the valve device according to the first embodiment; a cross-sectional view showing a second open state of the valve device according to the first embodiment; a cross-sectional view showing a first valve seat integrated with the bobbin according to the first embodiment; a cross-sectional view taken along line A-A in FIG. 3 showing a connection portion with the bobbin according to the first embodiment; an enlarged cross-sectional view showing a portion including the valve body in FIG. 1 according to the first embodiment; an enlarged cross-sectional view showing only the valve body and valve stem according to the first embodiment; an enlarged cross-sectional view showing only the first valve seat in FIG. 5 according to the first embodiment; an enlarged cross-sectional view showing only the second valve seat in FIG. 5 according to the first embodiment; an enlarged cross-sectional view showing a portion of the first valve seat surrounded by a chain line circle in FIG. 5 according to the first embodiment; a circuit diagram showing an example of use of the valve device according to the first embodiment; a simplified cross-sectional view of FIG. 5 showing the states of the valve bodies and valve seats in the first open state according to the first embodiment; 11 showing the state of each valve element and each valve seat in a second open state according to the first embodiment. FIG. 5 is an enlarged cross-sectional view showing a part of the valve device according to a second embodiment, according to an enlarged cross-sectional view showing a part of the first valve seat according to a comparative example. FIG. 6 is an enlarged cross-sectional view showing a part of the first valve seat according to a third embodiment.

[0028] Hereinafter, several embodiments embodying the "valve device" of this disclosed technique will be described in detail with reference to the drawings.

[0029] First Embodiment First, a valve device according to a first embodiment will be described in detail with reference to FIGS. 1 to 12. FIG.

[0030] [Configuration of the valve device] Figures 1 and 2 are cross-sectional views of the valve device 1. As shown in Figures 1 and 2, the valve device 1 includes a flow path housing 11 having a flow path, a valve seat 12, a valve element 13, a valve stem 14, and an actuator 15.

[0031] This valve device 1 constitutes a three-way valve. The flow path housing 11 includes a valve chamber 20 that houses a valve element 13, one inlet flow path 21, and two outlet flow paths 22. The valve chamber 20 constitutes one end of the inlet flow path 21. The flow path housing 11 corresponds to an example of a "flow path member" in the technology disclosed herein. In this embodiment, the flow path housing 11 is formed from resin.

[0032] The inlet flow path 21 is a flow path that communicates with the valve chamber 20 and is a flow path that allows fluid to flow into the valve chamber 20. The outlet flow path 22 is a flow path that allows fluid to flow out from the valve chamber 20. The two outlet flow paths 22 include a first outlet flow path 221 and a second outlet flow path 222. The first outlet flow path 221 is provided on the actuator 15 side of the valve chamber 20. The second outlet flow path 222 is provided on the opposite side of the valve chamber 20 from the actuator 15.

[0033] The valve seat 12 includes a first valve seat 121 and a second valve seat 122. The first valve seat 121 is disposed on the first outlet flow path 221 side of the valve chamber 20. The second valve seat 122 is disposed on the second outlet flow path 222 side of the valve chamber 20. The first valve seat 121 and the second valve seat 122 are both formed in an annular shape and have a first valve hole 16 and a second valve hole 17 in their centers, respectively. The valve seat 12 is formed from resin, but can also be formed from rubber.

[0034] The valve element 13 is attached to the lower end of the valve stem 14. The valve element 13 opens and closes the first valve hole 16 and the second valve hole 17 by abutting against and separating from the valve seat 12. In this embodiment, the valve element 13 includes a first valve element 131 and a second valve element 132 that are arranged at a distance 26 in the axial direction of the valve stem 14. A first seal member 18 is provided at the abutment portion of the first valve element 131 with the first valve seat 121. The first seal member 18 is adapted to abut against and separate from the first valve seat 121. A second seal member 19 is provided at the abutment portion of the second valve element 132 with the second valve seat 122. The second seal member 19 is adapted to abut against and separate from the second valve seat 122. Although the valve element 13 is made of resin in this embodiment, it may also be made of metal. The seal members 18, 19 are formed in the shape of an annular disk and are made of rubber, but may be made of other elastic materials. If the valve seat 12 is made of an elastic material, the seal members 18, 19 may be omitted.

[0035] The valve stem 14 is disposed inside the flow path housing 11 and the actuator 15. One end of the valve stem 14 is disposed in the actuator 15, and the other end of the valve stem 14 is disposed in the valve chamber 20. A valve element 13 is attached to the valve stem 14. The valve stem 14 is capable of reciprocating in the thrust direction, which is its axial direction. In this embodiment, the valve stem 14 is made of metal, but it can also be made of resin.

[0036] The actuator 15 is a member that moves the valve shaft 14 in the axial direction together with the valve element 13. The actuator 15 corresponds to an example of a "drive unit" in the technology disclosed herein. In this embodiment, the actuator 15 includes a movable core 31, a fixed core 32, a bobbin 33, a coil 34, a casing 35, and the like.

[0037] The movable core 31 is provided integrally with the valve stem 14. The movable core 31 moves in the axial direction, thereby moving the valve stem 14 in the axial direction. The fixed core 32 is disposed opposite the movable core 31 in the axial direction of the valve stem 14. A thrust bearing 36 for the valve stem 14 is provided between the upper end of the valve stem 14 and the fixed core 32. In addition, a compression spring 37 is provided on the outer periphery of the valve stem 14, between the thrust bearing 36 and the movable core 31, for urging the movable core 31 downward in Figures 1 and 2.

[0038] The movable core 31 and the fixed core 32 are made of a magnetic material (e.g., metal). When a current flows through the coil 34 and a magnetic field is generated around the coil 34, the movable core 31 and the fixed core 32 are magnetized by the magnetic field. When the movable core 31 and the fixed core 32 are magnetized, the movable core 31 is attracted to the fixed core 32 by magnetic force. At this time, the movable core 31 approaches the fixed core 32 together with the valve stem 14 against the biasing force of the compression spring 37. When no current flows through the coil 34, the movable core 31 and the fixed core 32 are not magnetized, and the movable core 31 is not attracted to the fixed core 32. At this time, the movable core 31, together with the valve stem 14, is separated from the fixed core 32 by the biasing force of the compression spring 37.

[0039] The bobbin 33 is formed in a cylindrical shape, and has a movable core 31 and a fixed core 32 provided inside and a coil 34 provided on the outside. The bobbin 33, the coil 34, etc. are molded and covered with resin to form a resin casing 35. A connector 35a protruding laterally is formed integrally with the casing 35. A terminal 34a extending from the coil 34 is provided on the connector 35a.

[0040] The valve device 1 configured as described above can be switched between a first open state shown in FIG. 1 and a second open state shown in FIG. 2 by moving the valve stem 14 in its axial direction using the actuator 15.

[0041] The "first open valve state" refers to a state in which the first valve seat 121 and the first valve body 131 are fully open, and the second valve seat 122 and the second valve body 132 are fully closed. The "second open valve state" refers to a state in which the first valve seat 121 and the first valve body 131 are fully closed, and the second valve seat 122 and the second valve body 132 are fully open. The "fully closed state" refers to a state in which the valve seat 12 and the valve body 13 abut on each other around the entire circumference of one end of the annular valve seat 12, sealing the gap between the valve seat 12 and the valve body 13.

[0042] 1, the fluid introduced from the inlet flow path 21 is discharged from the first outlet flow path 221. In the second open state shown in FIG. 2, the fluid introduced from the inlet flow path 21 is discharged from the second outlet flow path 222.

[0043] [Integration of the First Valve Seat and the Bobbin] Next, the integration of the first valve seat 121 and the bobbin 33 will be described. FIG. 3 shows a cross-sectional view of the first valve seat 121 integrated with the bobbin 33. FIG. 4 shows a cross-sectional view of the first valve seat 121 and the bobbin 33 taken along line A-A in FIG. 3 . In this embodiment, as shown in FIG. 3 , the first valve seat 121 is formed integrally with the bobbin 33, which is separate from the flow path housing 11. The bobbin 33 has a connecting portion 40 that extends coaxially with the valve stem 14 and is connected to the first valve seat 121 at the connection portion between the inlet flow path 21 and the first outlet flow path 221. That is, the first valve seat 121 and the bobbin 33 are formed integrally via the connecting portion 40. The first valve seat 121 and the connecting portion 40 are housed inside the flow path housing 11 (part of the first outlet flow path 221). In this embodiment, the bobbin 33 is provided integrally with the actuator 15. The bobbin 33 including the connecting portion 40 corresponds to an example of the "holding member" of the disclosed technology.

[0044] 3 and 4, the connecting portion 40 includes four pillar portions 41. These pillar portions 41 are formed in a substantially rectangular parallelepiped shape. The number of connecting portions 40 is not limited to four, and the connecting portion 40 may be configured with a number other than four.

[0045] In this embodiment, as shown in Fig. 4, the four pillars 41 are arranged at equal angular intervals in the circumferential direction of the annular first valve seat 121. That is, the four pillars 41 are arranged at equal intervals of 90° in the circumferential direction of the first valve seat 121. The pillars 41 have a substantially rectangular cross section and are arranged so that their long sides coincide with the radial direction of the first valve seat 121. Note that openings 42 through which fluid flows are formed between adjacent pillars 41. Note that the arrangement and cross-sectional shape of the four pillars 41 are not limited to those described above and can be changed as appropriate.

[0046] [Regarding the Shape of the Valve Disk] Next, the shape of the valve disk 13 of this embodiment will be described in detail. FIG. 5 is an enlarged cross-sectional view of a portion including the valve disk 13 of FIG. 1 . FIG. 6 is an enlarged cross-sectional view of only the valve disk 13 and the valve stem 14. As shown in FIGS. 5 and 6 , a predetermined gap 26 is provided between the first valve disk 131 and the second valve disk 132. Within this gap 26, the first valve disk 131 and the second valve disk 132 have valve disk facing walls 131 a, 132 a that face each other. The entire circumferential portion of each valve disk facing wall 131 a, 132 a has a tapered or R-shaped (an arc shape with a rounded radius R) extending from the valve stem 14 toward the corresponding outlet flow passages 221, 222. Note that a portion of the circumferential portion of each valve disk facing wall 131 a, 132 a may also be formed in a tapered or R-shaped shape extending from the valve stem 14 toward the corresponding outlet flow passages 221, 222.

[0047] 5 and 6, each of the valve bodies 131 and 132 has a valve seat-facing wall 131b or 132b that faces the corresponding valve seat 121 or 122. Each of the valve seat-facing walls 131b or 132b has an R-shape or a tapered shape that converges toward the corresponding valve hole 16 or 17.

[0048] [Regarding the Shape of the Valve Seat] Next, the shape of the valve seat 12 in this embodiment will be described in detail. Fig. 7 shows an enlarged cross-sectional view of only the first valve seat 121 in Fig. 5 . Fig. 8 shows an enlarged cross-sectional view of only the second valve seat 122 in Fig. 5 . In this embodiment, as shown in Figs. 5 and 7 , a converging inner wall 121a having an R-shape or a tapered shape that converges from the inlet flow path 21 to the first valve hole 16 is provided around the entire periphery of the first valve seat 121 on the side facing the first valve body 131. Furthermore, as shown in Figs. 5 and 8 , a converging inner wall 122a having an R-shape or a tapered shape that converges from the valve chamber 20 (inlet flow path 21) to the second valve hole 17 is provided on the side facing the first valve body 131 of the second valve seat 122.

[0049] In this embodiment, as shown in Figures 5 and 7, an annular valve seat ridge 121b capable of abutting against the first seal member 18 is formed on the valve disc-side opening edge of the first valve hole 16. Furthermore, as shown in Figures 5 and 8, an annular valve seat ridge 122b capable of abutting against the second seal member 19 is formed on the valve disc-side opening edge of the second valve hole 17. Each valve seat ridge 121b, 122b has an acute-angled tip that smoothly continues to the corresponding converging inner wall 121a, 122a, and is formed to surround each valve hole 16, 17.

[0050] Fig. 9 is an enlarged cross-sectional view of a portion of the first valve seat 121 surrounded by a chain-line circle S1 in Fig. 5. As shown in Fig. 9, the height H from the upper end of the inner wall of the introduction flow path 21 to the upper end of the convergent inner wall 121a is set to be greater than or equal to the radial height Rh of the convergent inner wall 121a. In this embodiment, the axial length of the first valve seat 121 is increased by the amount corresponding to the R-shaped or tapered convergent inner wall 121a provided on the side of the first valve seat 121 facing the first valve body 131. This increase in axial length increases the press-fit allowance of the first valve seat 121 in the flow path housing 11, thereby increasing the overall height of the valve device 1.

[0051] [Use Example of the Valve Device] A use example of the valve device 1 of this embodiment will be described. FIG. 10 shows a circuit diagram of a use example of the valve device 1 described above. As shown in FIG. 10 , in this embodiment, the valve device 1 is used in a cooling system 81 mounted on an electric vehicle 80. This cooling system 81 corresponds to an example of a "cooling system" in the disclosed technology. In this use example, the refrigerant flowing through the cooling system 81 corresponds to an example of a "fluid" in the disclosed technology. The electric vehicle 80 is, for example, a vehicle that includes a motor driven by power from a secondary battery as a drive source for the vehicle and travels by driving the drive wheels with the motor, and includes electric vehicles, hybrid vehicles, etc.

[0052] In this embodiment, the valve device 1 includes a first valve device 82 and a second valve device 83. In addition to the valve devices 82 and 83, the cooling system 81 also includes a heater 84, a battery 85, a DC-DC converter 86, a battery charger 87, a radiator 88, and an electric pump 89. Each of the valve devices 82 and 83 has an inlet 82a, 83a of the introduction flow path 21, a first outlet 82b, 83b of the first outlet flow path 221, and a second outlet 82c, 83c of the second outlet flow path 222. These components 82 to 89 are arranged along a main pipe 90 that circulates the refrigerant. The main pipe 90 includes a first pipe section 90a, a second pipe section 90b, and a third pipe section 90c.

[0053] A discharge port 89a of the electric pump 89 is connected to an inlet 82a of the first valve device 82 via a first piping section 90a. A second outlet 82c of the first valve device 82 is connected to an inlet 83a of the second valve device 83 via a second piping section 90b. A heater 84, a battery 85, a DC-DC converter 86, and a battery charger 87 are arranged in this order from the upstream side along the second piping section 90b. The first outlet 82b of the first valve device 82 is connected to the second piping section 90b via a first bypass piping 91, directly upstream of the DC-DC converter 86. The second outlet 83c of the second valve device 83 is connected to an inlet 89b of the electric pump 89 via a third piping section 90c. A radiator 88 is arranged along the third piping section 90c. The first outlet 83 b of the second valve device 83 is connected to the third piping section 90 c immediately upstream of the suction port 89 b of the electric pump 89 via a second bypass piping 92 .

[0054] In the cooling system 81, the flow of the refrigerant to each of the members 84 to 88 is switched by starting the electric pump 89 and driving the valve devices 82 and 83 to switch the flow paths.

[0055] In this embodiment, the valve devices 82 and 83 are used to switch between first, second, and third flow path patterns. The first flow path pattern is used to prevent overheating and overcooling of the battery 85. In the first flow path pattern, the electric pump 89 is started, the heater 84 is turned off, the first valve device 82 is switched to the first outlet 82b, and the second valve device 83 is switched to the second outlet 83c. As a result, refrigerant discharged from the electric pump 89 flows from the first valve device 82 through the first bypass pipe 91, the second pipe section 90b, and the third pipe section 90c, then through the DC-DC converter 86, the battery charger 87, the second valve device 83, and the radiator 88, before returning to the suction port 89b of the electric pump 89 and repeating this cycle. The first flow path pattern is used during low-speed driving in spring and autumn to maintain an appropriate temperature for the battery 85.

[0056] The second flow path pattern is switched to when cooling or waste-heating the battery 85. In this second flow path pattern, the electric pump 89 is started, the heater 84 is turned off, the first valve device 82 is switched to the second outlet 82c, and the second valve device 83 is switched to the second outlet 83c. As a result, the refrigerant discharged from the electric pump 89 flows from the first valve device 82 through the second piping section 90b and the third piping section 90c, sequentially through the heater 84, the battery 85, the DC-DC converter 86, the battery charger 87, the second valve device 83, and the radiator 88, and returns to the suction port 89b of the electric pump 89, repeating this circuit. The second flow path pattern is switched to when the temperature is high in summer or when the battery 85 is generating heat, to cool the battery 85.

[0057] The third flow path pattern is switched to when the battery 85 is heated by the heater 84. In this third flow path pattern, the electric pump 89 is started and the heater 84 is turned on, the first valve device 82 is switched to the second outlet 82c, and the second valve device 83 is switched to the first outlet 83b. As a result, the refrigerant discharged from the electric pump 89 flows from the first valve device 82 through the second piping section 90b, the second bypass piping section 92, and the third piping section 90c, sequentially through the heater 84, the battery 85, the DC-DC converter 86, the battery charger 87, and the second valve device 83, and returns to the suction port 89b of the electric pump 89, repeating this circuit. The third flow path pattern is switched to when the temperature is low in winter or when it is desired to quickly warm up the battery 85.

[0058] The battery 85 of the electric vehicle 80 has a characteristic that its performance deteriorates outside a certain temperature range. Therefore, in this embodiment, the temperature of the battery 85 and the refrigerant is monitored, and the above-mentioned flow path patterns are switched so that the temperature of the battery 85 is kept within the range of 25 to 35°C.

[0059] [Operation and Effects of the Valve Device and the Cooling System Including the Valve Device] According to the configuration of the valve device 1 of this embodiment described above, in the space 26 between the first valve device 131 and the second valve device 132 attached to the valve stem 14, the valve element-facing walls 131 a, 132 a of each valve element 131, 132 have a tapered or R-shaped configuration along at least a portion of their circumference, extending from the valve stem 14 toward the first outlet flow path 221 and the second outlet flow path 222. Therefore, the shape of each valve element-facing wall 131 a, 132 a reduces pressure loss of the fluid flowing from the introduction flow path 21 into the space 26 between the two valve elements 131, 132, and smooths the flow of the fluid from the space 26 toward the corresponding outlet flow paths 221, 222. This makes it possible to prevent the fluid flowing into the space 26 between the two valve elements 131, 132 on the valve stem 14 from stagnating.

[0060] According to the configuration of this embodiment, the first valve seat 121 is provided with a converging inner wall 121a having an R-shape or a tapered shape that converges from the inlet flow path 21 to the first valve hole 16. In addition, the second valve seat 122 is provided with a converging inner wall 122a having an R-shape or a tapered shape that converges from the valve chest 20 to the second valve hole 17. This reduces pressure loss of the fluid flowing from the inlet flow path 21 to the first valve hole 16 and the second valve hole 17, allowing the fluid to flow smoothly toward the first valve hole 16 and the second valve hole 17. This makes it possible to prevent the fluid flowing into the first valve hole 16 and the second valve hole 17 from stagnating.

[0061] According to the configuration of this embodiment, the valve seat-facing walls 131b, 132b of each valve disc 131, 132 facing the corresponding valve seat 121, 122 have an R-shaped or tapered shape that converges toward the corresponding valve hole 16, 17. Therefore, for each valve disc 131, 132, when the valve is open, the valve seat-facing walls 131b, 132b that converge into an R-shaped or tapered shape rectify the flow of fluid toward the valve hole 16, 17, reducing pressure loss of the fluid. This makes it possible to prevent the fluid flowing into the valve hole 16, 17 from stagnating.

[0062] Figure 11 is a cross-sectional view simplified from Figure 5, showing the states of the valve discs 131, 132 and the valve seats 121, 122 in the first open state. Figure 12 is a cross-sectional view equivalent to Figure 11, showing the states of the valve discs 131, 132 and the valve seats 121, 122 in the second open state. In Figures 11 and 12, dashed arrows indicate the "valve seat opening area SA," which represents the opening area of ​​each valve hole 16, 17 excluding the cross-sectional area of ​​the valve stem 14. Solid arrows indicate the "valve disc total circumferential area BA," which represents the opening area around the entire periphery of each valve disc 131, 132 due to the movement of each valve disc 131, 132. Dot-dash arrows indicate the "taper total circumferential area TA," which represents the opening area around the entire periphery of each valve seat-facing wall 131b, 132b due to the movement of each valve disc 131, 132.

[0063] In the first open state shown in FIG. 11 , fluid introduced into the inlet flow path 21 flows through the first valve orifice 16 of the first valve seat 121 to the first outlet flow path 221. Here, the tapered total circumferential area TA is larger than the smaller side of the valve disc total circumferential area BA and the valve seat opening area SA. Furthermore, if the valve disc total circumferential area BA is larger than the valve seat opening area SA, tapering the first valve orifice 16 would further reduce the minimum opening area of ​​the valve seat opening area SA. This reduction in the minimum opening area would increase pressure loss. Therefore, tapering the first valve orifice 16 is not possible. Fluid flowing from the inlet flow path 21 into the gap 26 between the valve discs 131 and 132 flows toward the first valve orifice 16 of the first valve seat 121, as indicated by the bold arrow. At this time, the fluid flows while smoothly bending along the curved surface of the valve seat-facing wall 131b and passes downstream through the first valve orifice 16.

[0064] 12 , the fluid introduced into the inlet flow path 21 flows to the second outlet flow path 222 via the second valve orifice 17 of the second valve seat 122. Here again, the tapered circumferential area TA is larger than the smaller side of the valve disc circumferential area BA and the valve seat opening area SA. Furthermore, if the valve disc circumferential area BA is larger than the valve seat opening area SA, forming a taper in the second valve orifice 17 would further reduce the minimum opening area of ​​the valve seat opening area SA, increasing pressure loss due to the reduced opening area of ​​the minimum opening area portion. Therefore, forming a taper in the second valve orifice 17 is not possible. The valve seat-facing wall 132b of the second valve body 132 does not have the valve stem 14, so the taper and R-shape can be larger than those of the valve seat-facing wall 131b of the first valve body 131. The fluid that has flowed from the inlet flow path 21 into the gap 26 between the valve bodies 131, 132 flows toward the second valve hole 17 of the second valve seat 122, as indicated by the thick arrow. At this time, the fluid passes through the second valve hole 17 downstream while bending along the curved surface of the valve seat-facing wall 132b and forming a smooth flow.

[0065] According to the configuration of this embodiment, the first valve seat 121 is formed integrally with the bobbin 33, which is separate from the flow path housing 11, which allows for greater flexibility in molding the first valve seat 121 than if the first valve seat 121 were formed in the flow path housing 11. Furthermore, the bobbin 33 has a connecting portion 40 that extends coaxially with the valve stem 14 and is connected to the first valve seat 121 at the connection portion between the inlet flow path 21 and the first outlet flow path 221, so the connecting portion 40 does not restrict movement of the valve stem 14. Therefore, it is possible to easily form an R-shaped or tapered converging inner wall 121a or a valve seat ridge 121b around the first valve hole 16 of the first valve seat 121.

[0066] According to the configuration of this embodiment, the bobbin 33 on which the first valve seat 121 is formed is provided integrally with the actuator 15, so that when the actuator 15 is assembled to the flow path housing 11, the first valve seat 121 is simultaneously assembled to the flow path housing 11. Therefore, the step of assembling only the first valve seat 121 to the flow path housing 11 can be omitted.

[0067] In this embodiment, the first valve seat 121 and the bobbin 33 are formed as a single component, which reduces the number of components in the valve device 1 and allows the manufacturing cost of the valve device 1 to be reduced.

[0068] In addition, in this embodiment, the connecting portion 40 is composed of four pillar portions 41 arranged at equal angular intervals, so the shape of the connecting portion 40 can be simplified and the flow path resistance in the first outlet flow path 221 can be reduced.

[0069] Furthermore, in this embodiment, the first valve seat 121 and the bobbin 33 are integrally formed via the connecting portion 40, so that the first valve seat 121 and the bobbin 33 are positioned properly. This reduces axial misalignment (i.e., misalignment of the central axes) between the first valve hole 16 of the first valve seat 121 and the bobbin 33, thereby reducing axial misalignment between the first valve hole 16 and the valve stem 14 disposed inside the bobbin 33. As a result, the centering accuracy (i.e., the accuracy with which the central axes coincide) between the first valve seat 121 and the first valve body 131 can be improved. Furthermore, when the first valve seat 121 and the first valve body 131 are in a fully closed state (i.e., the second open state in FIG. 2 ), the gap between the first valve seat 121 and the first valve body 131 is sealed, thereby reducing fluid leakage between the first valve seat 121 and the first valve body 131.

[0070] Furthermore, in this embodiment, the integration of the first valve seat 121 with the bobbin 33 simplifies the function of holding the first valve seat 121. That is, if the first valve seat and the bobbin were formed separately, a function for fixing the first valve seat to prevent misalignment would be required. Therefore, for example, in order to press-fit the first valve seat into the body, it would be necessary to increase the thickness of the body to ensure strength. In contrast, in this embodiment, the first valve seat 121 and the bobbin 33 are formed integrally, making it difficult for the first valve seat 121 to shift position, and measures to prevent the first valve seat 121 from shifting position are not necessary. Therefore, for example, there is no need to press-fit the first valve seat 121 into the flow path housing 11, and the thickness of the flow path housing 11 can be reduced. Furthermore, the configuration for holding the first valve seat 121 can be simplified.

[0071] According to the configuration of this embodiment, the valve device 1 is used in a cooling system 81 mounted on an electric vehicle 80, and therefore, the same effects as those described above can be obtained in the cooling system 81 of the electric vehicle 80. Furthermore, in the cooling system 81, the flow efficiency of the fluid in the valve device 1 is improved. Therefore, the valve device 1 used in the cooling system 81 of the electric vehicle 80 can obtain the same effects as those described above. Furthermore, the energy efficiency of the cooling system 81 of the electric vehicle 80 can be improved, which can contribute to carbon neutrality.

[0072] In this embodiment, the valve device 1 is a device used in a cooling system 81 of an electric vehicle 80. Here, when the first valve seat 121 and the first valve body 131 are fully closed, contact between the valve seat ridge 121b and the first seal member 18 can reduce refrigerant leakage between the first valve seat 121 and the first valve body 131. This allows the flow rate of the refrigerant to be controlled with high precision. Therefore, the refrigerant can be flowed at a flow rate required by the electric vehicle 80. In this sense, the energy efficiency of the electric vehicle 80 can be improved, contributing to carbon neutrality.

[0073] Second Embodiment Next, a valve device according to a second embodiment will be described in detail with reference to Fig. 13. In the following description, components equivalent to those in the first embodiment will be denoted by the same reference numerals and description thereof will be omitted, and differences will be mainly described.

[0074] [Regarding the Shape of the Valve Seat] This embodiment differs from the first embodiment in the shape of the first valve seat 121. Fig. 13 is a cross-sectional view equivalent to Fig. 5 showing a portion of the valve device 1. Unlike the first embodiment, in this embodiment, as shown in Fig. 13, the inner wall of the first valve seat 121 outside the valve seat ridge 121b does not have a convergent inner wall 121a on the side closer to the introduction flow path 21 (the right side in Fig. 11) and has a flat shape, while the convergent inner wall 121a has an R-shape or a tapered shape on the side farther from the introduction flow path 21 (the left side in Fig. 11).

[0075] [Regarding Function and Effect of the Valve Device] According to the configuration of the valve device 1 of this embodiment described above, unlike the first embodiment, the inner wall of the first valve seat 121 outside the valve seat ridge 121b does not have a convergent inner wall 121a on the side closer to the inlet flow path 21 (the right side in FIG. 11), but has a flat shape, as shown in Fig. 13. Therefore, the height of the flow path housing 11 is slightly reduced by the amount of the flat shape compared to the first embodiment, and the flow path length to the first outlet flow path 221 is shortened, thereby making it possible to reduce pressure loss accordingly.

[0076] Third Embodiment Next, a valve device according to a third embodiment will be described in detail with reference to FIGS. 14 and 15. FIG.

[0077] [Regarding the Shape of the Valve Seat] Fig. 14 is an enlarged cross-sectional view of a portion of the first valve seat 121 according to a comparative example (each of the above-described embodiments). In each of the above-described embodiments, as shown in Fig. 14 , an annular valve seat ridge 121b, which can abut against the first seal member 18, is formed on the valve-disc-side opening edge of the first valve hole 16 so as to continue along the R-shaped or tapered convergent inner wall 121a. Therefore, as shown by the arrows in Fig. 14 , there is a risk that the fluid flow along the convergent inner wall 121a will collide with the valve seat ridge 121b and become turbulent, resulting in pressure loss. Therefore, in this embodiment, the convergent inner wall 121a located inside the valve seat ridge 121b is configured as follows.

[0078] Fig. 15 shows an enlarged cross-sectional view of a portion of the first valve seat 121 according to this embodiment. As shown in Fig. 15, in this embodiment, unlike the first embodiment, an annular valve seat groove 121c is formed along the valve seat ridge 121b in the convergent inner wall 121a located inside the valve seat ridge 121b of the first valve seat 121. The opening of this valve seat groove 121c is formed following an imaginary continuous line L1 that continues into the R-shape or tapered shape of the convergent inner wall 121a, and this imaginary continuous line L1 connects to the tip of the valve seat ridge 121b.

[0079] Although not shown in the drawings or explained, the second valve seat 122 may also have an annular valve seat groove formed along the valve seat ridge 122b on the converging inner wall 122a inside the valve seat ridge 122b in the same manner as described above.

[0080] [Regarding Function and Effect of the Valve Device] According to the configuration of the valve device 1 of this embodiment described above, unlike the first embodiment, each valve disc 131, 132 is provided with a respective seal member 18, 19 at the portion where it abuts against the respective valve seat 121, 122, and each valve hole 16, 17 has an annular valve seat ridge 121b, 122b on the valve disc side opening edge that can abut against the respective seal member 18, 19. Therefore, the abutment between each valve seat 121, 122 and the corresponding valve disc 131, 132 is achieved by the engagement contact between each valve seat ridge 121b, 122b and each seal member 18, 19. Furthermore, the opening of the valve seat groove 121c formed in the convergent inner wall 121a inside the valve seat ridge 121b of the first valve seat 121 is formed following an imaginary continuous line L1 that continues into the R-shaped or tapered shape of the convergent inner wall 121a, and the imaginary continuous line L1 connects to the tip of the valve seat ridge 121b. Therefore, fluid flowing along the R-shaped or tapered shape of the convergent inner wall 121a of the first valve seat 121 flows downstream without colliding with the valve seat ridge 121b (see FIG. 14). Therefore, when the first valve seat 121 is fully closed (see FIG. 2), the engagement between the valve seat ridge 121b and the first seal member 18 improves the sealing performance of the first valve seat 121. Furthermore, when the first valve seat 121 is open (see FIG. 1), fluid retention inside the valve seat ridge 121b of the first valve seat 121 can be suppressed.

[0081] <Other Embodiments> The disclosed technology is not limited to the above-described embodiments, and can be implemented by appropriately modifying part of the configuration within the scope of the disclosed technology.

[0082] (1) In each of the above-described embodiments, both of the valve element-facing walls 131 a, 132 a of each valve element 131, 132 have a tapered or rounded shape toward the corresponding first outlet flow path 221 or second outlet flow path 222. However, one of the valve element-facing walls 131 a, 132 a of each valve element 131, 132 may have a tapered or rounded shape toward the corresponding first outlet flow path 221 or second outlet flow path 222.

[0083] (2) In the above-described embodiments, both of the converging inner walls 121 a, 122 a of the valve seats 121, 122 that converge to the valve holes 16, 17 are tapered or rounded. However, one of the converging inner walls 121 a, 122 a of the valve seats 121, 122 may be tapered or rounded.

[0084] (3) In the above-described embodiments, both of the valve seat-facing walls 131 b, 132 b of the valve discs 131, 132 have an R-shaped or tapered shape that converges toward the corresponding valve holes 16, 17. However, one of the valve seat-facing walls 131 b, 132 b of the valve discs 131, 132 may also have an R-shaped or tapered shape that converges toward the corresponding valve holes 16, 17.

[0085] The disclosed technology can be used in fluid circuits of cooling systems mounted on electric vehicles and the like.

[0086] REFERENCE SIGNS LIST 1 valve device 11 flow path housing (flow path member) 12 valve seat 121 first valve seat 121a convergent inner wall 121b valve seat ridge 121c valve seat groove 122 second valve seat 122a convergent inner wall 122b valve seat ridge 13 valve disc 131 first valve disc 131a valve disc facing wall 131b valve seat facing wall 132 second valve disc 132a valve disc facing wall 132b valve seat facing wall 14 valve stem 15 actuator (driving part) 16 first valve hole 17 second valve hole 18 first seal member 19 second seal member 20 valve chamber (inlet flow path) 21 inlet flow path 22 outlet flow path 221 first outlet flow path 222 second outlet flow path 26 spacing 33 bobbin (holding member) 40: coupling portion 80: electric vehicle 81: cooling system (cooling system) L1: virtual continuous line

Claims

1. A valve device comprising: a flow path member; an inlet flow path formed in the flow path member for introducing a fluid; a first outlet flow path formed in the flow path member for outletting the fluid introduced from the inlet flow path; a second outlet flow path formed in the flow path member for outletting the fluid introduced from the inlet flow path; a first valve seat provided in the flow path member between the inlet flow path and the first outlet flow path; a second valve seat provided in the flow path member between the inlet flow path and the second outlet flow path; a first valve body abutting against and separating from the first valve seat; a second valve body abutting against and separating from the second valve seat; a valve shaft to which the first valve body and the second valve body are attached; and a drive section for driving the valve shaft, wherein a predetermined interval is provided between the first valve body and the second valve body, and within the interval, the valve bodies have valve body opposing walls opposing each other, the valve device, wherein at least a portion of the circumferential direction of each of the valve body opposing walls has a tapered shape or an R shape extending from the valve stem toward the corresponding one of the outlet flow paths.

2. A valve device as claimed in claim 1, comprising: a first valve hole formed in said first valve seat; and a second valve hole formed in said second valve seat, wherein at least one of said valve seats is provided with an R-shaped or tapered converging inner wall that converges from said introduction flow path to the corresponding one of said valve holes.

3. A valve device as claimed in claim 2, wherein each of the valve bodies is provided with a sealing member at the contact portion with the corresponding valve seat, at least one of the valve body side opening edges of each of the valve holes is provided with an annular valve seat ridge capable of contacting the sealing member, a valve seat groove is formed in the converging inner wall on the inside of the valve seat ridge, and the opening of the valve seat groove is formed following an imaginary continuous line continuing to the R-shape or tapered shape of the converging inner wall, and the imaginary continuous line is connected to the tip of the valve seat ridge.

4. A valve device as claimed in any one of claims 1 to 3, characterized in that each of the valve bodies has a valve seat facing wall facing the corresponding one of the valve seats, and at least one of the valve seat facing walls has an R-shape or a tapered shape converging towards the corresponding one of the valve holes.

5. A valve device as claimed in any one of claims 1 to 3, characterized in that the first valve seat is formed integrally with a retaining member which is separate from the flow path member, and the retaining member has a connecting portion which extends coaxially with the valve stem at the connection between the inlet flow path and the first outlet flow path and is connected to the first valve seat.

6. The valve device according to claim 5, wherein the retaining member is provided integrally with the drive portion.

7. The valve device according to any one of claims 1 to 3, characterized in that the valve device is used in a cooling system mounted on an electric vehicle.

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