Valve device

Abstract

A valve device (1) includes: a lead-in flow path (21); lead-out flow paths (221, 222); valve bodies (131, 132) for switching communication / closure of the flow paths (21, 221, 222); valve seats (121, 122) on which the corresponding valve bodies (131, 132) are seated; a valve shaft (14) for integrally moving the valve bodies (131, 132); an actuator (15) for driving the valve shaft (14); a spring (37) for urging the valve shaft (14) in one direction; seal members (18, 19) provided on one side of a contact section between the valve bodies (131, 132) and the valve seats (121, 122); and valve seat protrusions (121a, 122a) provided on the other side thereof. In order to suppress the surface pressure at the contact section between the valve body (132) and the valve seat (122) where the seating load is higher than elsewhere, the seal member (19) and the valve seat protrusion (122a) are configured by selectively combining one of the multiple seal members having different trait characteristics and one of the multiple valve seat protrusions having different trait characteristics.

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 conventional technique of this type is known, for example, from Patent Document 1. This technique relates to a flow dividing valve (valve device) that divides 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 formed between the inlet flow path and the first outlet flow path, a second valve seat formed between the inlet flow path and the second outlet flow path, a first valve element that abuts against and moves away from the first valve seat, a second valve element that abuts against and moves away 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) that drives the valve stem, and is configured as a three-way valve.

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

[0004] In the valve device described in Patent Document 1, differences in the fluid pressure acting on each flow path, the biasing force of the spring provided in the drive unit, the driving force of the drive unit, and pressure loss in each flow path can cause a difference between the load (seating load) when the first valve element seats on the first valve seat and the load when the second valve element seats on the second valve seat. To improve sealing, it is conceivable to provide an elastic member, such as a seal member, at the contact point between each valve element and its corresponding valve seat, and have a rigid member contact the elastic member. However, when there is a difference in the seating load between the first valve seat and the second valve seat, the surface pressure at the contact point between the elastic member and the rigid member becomes excessively high on the side with the higher seating load, which can cause the elastic member to easily sag and potentially reduce its durability. Here, "sag" refers to permanent deformation or performance degradation of an object over long-term use.

[0005] This disclosed technology has been made in consideration of the above circumstances, and its purpose is to provide a valve device in which, for an elastic member and a rigid member provided at the contact portion between a plurality of valve bodies and a corresponding plurality of valve seats, the surface pressure at the contact portion where the seating load between the valve body and the valve seat is higher than at other portions can be suppressed, thereby making it possible to suppress wear of the elastic member at the contact portion.

[0006] (1) In order to achieve the above object, one aspect of the technology disclosed in the present application provides a valve device including an inlet flow path, a plurality of outlet flow paths branching in at least two directions from the inlet flow path and for discharging a fluid, a plurality of valve elements for switching between communication and closing between the inlet flow path and one of the plurality of outlet flow paths, a plurality of valve seats provided corresponding to each of the plurality of outlet flow paths and on which one of the plurality of valve elements is seated, a valve stem for moving the plurality of valve elements together in the axial direction, a drive unit for driving the valve stem in the axial direction, a spring for biasing the valve stem to one side in the axial direction, and an elastic member provided on one side of an abutment between the valve element and the valve seat when one of the plurality of valve elements seats on one of the corresponding plurality of valve seats, wherein the valve device selectively combines one of a plurality of elastic members with different properties and one of a plurality of rigid members with different properties in order to suppress the surface pressure at the abutment where the seating load between the valve element and the valve seat becomes higher than at other parts.

[0007] According to the above configuration (1), when one of the plurality of valve discs is seated on one of the corresponding plurality of valve seats, the elastic member provided on one side of the contact portion between the valve disc and the valve seat and the rigid member provided on the other side come into contact. Here, in order to suppress the surface pressure at the contact portion where the seating load between the valve disc and the valve seat is higher than at other portions, one of the plurality of elastic members with different properties and one of the plurality of rigid members with different properties are selectively combined.

[0008] (2) In order to achieve the above object, in the configuration of (1) above, it is preferable that the rigid member includes, as one of its physical characteristics, a convex rib that abuts against a corresponding elastic member, and that the radial size of the convex rib at the abutment portion that applies a higher load when the valve body is seated on the valve seat is smaller based on the driving force of the driving unit, the biasing force of the spring, the pressure of the fluid, and the pressure loss in the inlet flow path and the outlet flow path.

[0009] According to the configuration (2) above, in addition to the effect of the configuration (1) above, the actual pressure of the fluid acting on the valve element corresponding to the convex ridge of the abutment portion, which has a higher load (seating load) when the valve element seats on the valve seat, becomes smaller.

[0010] (3) To achieve the above object, in the configuration of (1) above, it is preferable that the harder the elastic member of the abutting portion is, the higher the load that occurs when the valve element seats on the valve seat, based on the driving force of the driving portion, the biasing force of the spring, the pressure of the fluid, and the pressure loss in the inlet and outlet flow paths.

[0011] According to the configuration (3), in addition to the effect of the configuration (1), the elastic member of the contact portion where the seating load is higher has a higher hardness, so that deformation strain of the elastic member is reduced.

[0012] (4) To achieve the above object, in the configuration of (1) above, it is preferable to increase the thickness of the elastic member of the abutment portion where the load applied when the valve element seats on the valve seat is higher, based on the driving force of the driving portion, the biasing force of the spring, the pressure of the fluid, and the pressure loss in the inlet and outlet flow paths.

[0013] According to the configuration (4) above, in addition to the effect of the configuration (1) above, the thickness of the elastic member at the contact portion where the seating load is higher is greater, so that stress concentration on the elastic member is alleviated.

[0014] (5) In order to achieve the above object, in the configuration of (1) above, it is preferable that the rigid member includes, as one of its physical characteristics, a convex rib that abuts against a corresponding elastic member, and that the convex rib at the abutment portion that applies a higher load when the valve body is seated on the valve seat based on the driving force of the driving unit, the biasing force of the spring, the pressure of the fluid, and the pressure loss in the inlet flow path and the outlet flow path has a larger curvature radius at its apex.

[0015] According to the configuration (5) above, in addition to the effect of the configuration (1) above, the convex stripes at the contacting portions with higher seating loads have a larger curvature radius at their apexes, so that an increase in surface pressure at the apexes of the convex stripes is suppressed.

[0016] (6) In order to achieve the above object, in the configuration of (1) above, it is preferable that the rigid member includes, as one of its physical characteristics, a convex rib that abuts against a corresponding elastic member, and that the width of the convex rib at the abutment portion is made larger as the load when the valve body is seated on the valve seat increases based on the driving force of the driving unit, the biasing force of the spring, the pressure of the fluid, and the pressure loss in the inlet flow path and the outlet flow path.

[0017] According to the configuration (6) above, in addition to the effect of the configuration (1) above, the width of the protruding strips in the contacting portion where the seating load is higher is larger, so that an increase in the surface pressure at the protruding strips is suppressed.

[0018] (7) In order to achieve the above object, in the configuration of (1) above, it is preferable that the rigid member includes, as one of its physical characteristics, a convex rib that abuts against a corresponding elastic member, and that the protruding height of the convex rib at the abutment portion is smaller as the load when the valve body is seated on the valve seat increases based on the driving force of the driving unit, the biasing force of the spring, the pressure of the fluid, and the pressure loss in the inlet flow path and the outlet flow path.

[0019] According to the configuration (7) above, in addition to the effect of the configuration (1) above, the protruding height of the convex rib of the contact portion where the seating load is higher is smaller, so that the seating load is borne by the convex rib and the flat surface around it, and an increase in the surface pressure on the convex rib is suppressed.

[0020] (8) In order to achieve the above object, in any of the configurations (1) to (7), the valve device is preferably used in a cooling system mounted on an electric vehicle.

[0021] According to the configuration (8) above, the same effect as any of the configurations (1) to (7) above can be obtained as a valve device used in a cooling system mounted on an electric vehicle.

[0022] According to the above configuration (1), the elastic members and rigid members provided at the contact points between the multiple valve bodies and the corresponding multiple valve seats can suppress the surface pressure at the contact points where the seating load between the valve bodies and the valve seats becomes higher than at other points, and can suppress the wear of the elastic members at the contact points.

[0023] According to the configuration (2) above, similar to the effect of the configuration (1) above, it is possible to suppress the surface pressure at the contact portion where the seating load is higher than other portions, and it is possible to suppress the wear of the elastic member at that contact portion.

[0024] According to the configuration (3) above, similar to the effect of the configuration (1) above, it is possible to suppress the surface pressure at the contact portion where the seating load is higher than at other portions, and it is possible to suppress the wear of the elastic member at that contact portion.

[0025] According to the configuration (4) above, similar to the effect of the configuration (1) above, it is possible to suppress the surface pressure at the contact portion where the seating load is higher than at other portions, and it is possible to suppress the wear of the elastic member at that contact portion.

[0026] According to the configuration (5) above, similar to the effect of the configuration (1) above, it is possible to suppress the surface pressure at the contact portion where the seating load is higher than at other portions, and it is possible to suppress the wear of the elastic member at that contact portion.

[0027] According to the configuration (6) above, similar to the effect of the configuration (1) above, it is possible to suppress the surface pressure at the contact portion where the seating load is higher than at other portions, and it is possible to suppress the wear of the elastic member at that contact portion.

[0028] According to the configuration (7) above, similar to the effect of the configuration (1) above, it is possible to suppress the surface pressure at the contact portion where the seating load is higher than at other portions, and it is possible to suppress the wear of the elastic member at that contact portion.

[0029] According to the configuration (8) above, it is possible to obtain the same effect as any one of the configurations (1) to (7) above.

[0030] 1 is a cross-sectional view showing the valve device in a first open state according to the first embodiment; FIG. 2 is a cross-sectional view showing the valve device in a second open state according to the first embodiment; FIG. 3 is a cross-sectional view showing the integrated first valve seat and bobbin according to the first embodiment; FIG. 4 is a cross-sectional view taken along line A-A in FIG. 3 showing the connection between the first valve seat and the bobbin according to the first embodiment; FIG. 5 is an enlarged cross-sectional view showing the valve disc and valve seat portion of FIG. 1 according to the first embodiment; FIG. 6 is a cross-sectional view showing the fluid flow in the valve device in a first open state according to the first embodiment; FIG. 7 is a cross-sectional view showing the fluid flow in the valve device in a second open state according to the first embodiment; FIG. 8 is a graph showing the relationship between the valve seat surface pressure and the wear of the seal member according to the first embodiment; FIG. 9 is a graph showing the relationship between the valve seat surface pressure and the leakage amount at the seal member according to the first embodiment; FIG. 11 is a circuit diagram showing an example of use of the valve device according to the first embodiment; FIG. 12 is an enlarged cross-sectional view of a portion of FIG. 5 showing the relationship between the fluid pressure acting on the second valve disc in a seated state according to the first embodiment; 10 is an enlarged cross-sectional view showing a portion of the first valve body seated on the first valve seat according to a second embodiment; an enlarged cross-sectional view showing a portion of the second valve body seated on the second valve seat according to a second embodiment; an enlarged cross-sectional view showing a portion of the first valve body seated on the first valve seat according to a third embodiment; an enlarged cross-sectional view showing a portion of the second valve body seated on the second valve seat according to a third embodiment; a graph showing the relationship between the apex curvature radius of the valve seat ridge and the valve seat surface pressure according to the third embodiment; an enlarged cross-sectional view showing a portion of the first valve body seated on the first valve seat according to a fourth embodiment; an enlarged cross-sectional view showing a portion of the second valve body seated on the second valve seat according to the fourth embodiment; an enlarged cross-sectional view showing a portion of the first valve body seated on the first valve seat according to a fifth embodiment; an enlarged cross-sectional view showing a portion of the second valve body seated on the second valve seat according to a fifth embodiment; a cross-sectional view showing a portion of the second valve body seated on the second valve seat according to a sixth embodiment; a cross-sectional view showing a valve device in a first open state according to a sixth embodiment. 10 is a cross-sectional view showing the valve device in a second open state according to the sixth embodiment; a cross-sectional view showing the valve device in a first open state according to the seventh embodiment; a cross-sectional view showing the valve device in a second open state according to the seventh embodiment; a schematic cross-sectional view showing the second valve body and the second valve seat in the open state according to the first to sixth embodiments; and a schematic cross-sectional view showing the second valve body and the second valve seat in the open state according to the eighth embodiment.

[0031] Hereinafter, several embodiments embodying the "valve device" of this disclosed technique will be described in detail with reference to the drawings.

[0032] First Embodiment First, a valve device 1 according to a first embodiment will be described in detail with reference to FIGS. 1 to 11. FIG.

[0033] [Configuration of the valve device] Figures 1 and 2 show cross-sectional views of a valve device 1 according to this embodiment. As shown in Figures 1 and 2, the valve device 1 includes a flow path housing 11 having a plurality of flow paths, a valve seat 12, a valve element 13, a valve stem 14, and an actuator 15.

[0034] 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. In this embodiment, the flow path housing 11 is made of resin.

[0035] The inlet flow path 21 is a flow path through which fluid flows into the valve chamber 20. The outlet flow path 22 is a flow path through which fluid flows out of 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.

[0036] 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.

[0037] The valve element 13 is attached to the lower end of the valve stem 14 and 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 spaced apart axially along the valve stem 14 at a distance 26. 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. In this embodiment, the valve element 13 is made of resin, but may also be made of metal. The seal members 18, 19 are formed into annular disk shapes of the same dimensions from rubber, but may also be made of other elastic materials.

[0038] 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. The other end of the valve stem 14 is disposed in the valve chamber 20, and the valve element 13 is attached to it. 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.

[0039] The actuator 15 is a member that moves the valve shaft 14 in the axial direction together with the valve element 13, and corresponds to an example of a "drive unit" in the disclosed technology. In this embodiment, the actuator 15 includes a movable core 31, a fixed core 32, a bobbin 33, a coil 34, a casing 35, etc., and is configured as a "solenoid."

[0040] The movable core 31 is provided integrally with the valve stem 14 and moves axially to move 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, to urge the movable core 31 downward in Figures 1 and 2.

[0041] 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, and 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, the movable core 31 is not attracted to the fixed core 32, and the movable core 31, together with the valve stem 14, moves away from the fixed core 32 due to the biasing force of the compression spring 37.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] In this embodiment, the first valve seat 121 and the bobbin 33 are integrally formed. FIG. 3 shows a cross-sectional view of the integrated first valve seat 121 and bobbin 33 according to this embodiment. FIG. 4 shows a cross-sectional view of the A-A line in FIG. 3 showing a connecting portion 40 between the first valve seat 121 and the bobbin 33 according to this embodiment. In this embodiment, as shown in FIG. 3, the first valve seat 121 is integrally formed with the bobbin 33, which is separate from the flow path housing 11. The bobbin 33 has a connecting portion 40 at the connection between the inlet flow path 21 and the first outlet flow path 221, and the connecting portion 40 is held coaxially with the valve stem 14. In other words, the first valve seat 121 and the bobbin 33 are integrally formed 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).

[0047] In this embodiment, as shown in FIG. 4 , the connecting portion 40 includes four pillar portions 41. The number of pillar portions 41 is not limited to four and may be any number other than four. The four pillar portions 41 are arranged at equal angular intervals from one another in the circumferential direction of the annular first valve seat 121. That is, the four pillar portions 41 are evenly arranged at 90° intervals in the circumferential direction of the first valve seat 121. The pillar portions 41 have a substantially rectangular cross section and are arranged so that the long side direction coincides with the radial direction of the first valve seat 121. Note that an opening 42 through which a fluid flows is formed between adjacent pillar portions 41.

[0048] [Regarding the Shape of the Valve Disk] Next, the shape of the valve disk 13 of this embodiment will be described. Fig. 5 is an enlarged cross-sectional view of the valve disk 13 and valve seat 12 of Fig. 1 according to this embodiment. As shown in Fig. 5, a predetermined gap 26 is provided between the first valve disk 131 and the second valve disk 132. At this gap 26, the opposing surfaces of the first valve disk 131 and the second valve disk 132 are flat.

[0049] 5 , a first seal member 18 capable of abutting against the first valve seat 121 is provided at the seating portion of the first valve body 131 where it contacts the first valve seat 121. A second seal member 19 capable of abutting against the second valve seat 122 is provided at the seating portion of the second valve body 132 where it contacts the second valve seat 122. Each seal member 18, 19 is inherently elastic and corresponds to an example of the "elastic member" of the disclosed technology. Each valve body 131, 132 has opposing walls 131 a, 132 a that converge toward the valve holes 16, 17 of the corresponding valve seats 121, 122.

[0050] [Regarding the Shape of the Valve Seat] Next, the shape of the valve seat 12 of this embodiment will be described. As shown in FIG. 5 , the first valve hole 16 has an annular first valve seat ridge 121a formed on the valve-disk-side opening edge thereof, which can abut against the first seal member 18. Also, as shown in FIG. 5 , the second valve hole 17 has an annular second valve seat ridge 122a formed on the valve-disk-side opening edge thereof, which can abut against the second seal member 19. Each valve seat ridge 121a, 122a protrudes from the flat surface of the corresponding valve seat 121, 122 and is formed to surround each valve hole 16, 17. Each valve seat ridge 121a, 122a is characteristically more rigid than each seal member 18, 19 and is an example of a "rigid member" in the disclosed technology. Here, "rigid member" refers to a member with higher rigidity than an "elastic member."

[0051] [Issues Related to Seal Members] Here, issues related to the seal members 18, 19 will be described. In the three-way valve device 1 of this embodiment, when the valve elements 131, 132 seat on the corresponding valve seats 121, 122, a difference in load (seating load) occurs between the first valve element 131 and the first valve seat 121 and between the second valve element 132 and the second valve seat 122. This difference is caused by factors such as the pressure of the fluid flowing into the introduction flow path 21 (fluid pressure), the biasing force of the compression spring 37 (spring biasing force), and the driving force of the actuator 15 (actuator driving force). On the side where the seating load is higher, the surface pressure at the contact portion between the valve elements 131, 132 and the valve seats 121, 122 is higher. The contact portion here is formed by the seal members 18, 19 and the corresponding valve seat ridges 121a, 122a. Although the rubber seal members 18, 19 have excellent sealing properties, they have a characteristic that the surface pressure caused by contact with the corresponding valve seat ridges 121a, 122a becomes high, and the higher the surface pressure, the more easily the seal members 18, 19 wear down.

[0052] Fig. 6 is a cross-sectional view showing the flow of fluid through the valve device 1 in a first open state according to this embodiment. Fig. 7 is a cross-sectional view showing the flow of fluid through the valve device 1 in a second open state according to this embodiment. Here, for example, assume that in the first open state shown in Fig. 6, a high pump discharge pressure acts on the inlet flow path 21, and in the second open state shown in Fig. 7, a medium pump discharge pressure acts on the inlet flow path 21. Under this assumption, based on the relationship between the fluid pressure, the spring biasing force, and the actuator driving force, a large flow path differential pressure and spring biasing force act on the second valve body 132 in the first open state, and a medium flow path differential pressure and the difference between the actuator driving force and the spring biasing force act on the first valve body 131 in the second open state. Therefore, the influence of the differential pressure across each valve element 131, 132 is large, and in the first open state, the seating load between the second valve element 132 and the second valve seat 122 is high, and in the second open state, the seating load between the first valve element 131 and the first valve seat 121 is low. Under this assumption, if a seal design is used that presupposes ensuring sealing between the first valve element 131 and the first valve seat 121, the surface pressure at the contact portion between the second valve element 132 and the second valve seat 122 in the first open state will be excessive, raising concerns that the resistance of the second seal member 19 to settling will be reduced.

[0053] FIG. 8 is a graph showing the relationship between the "surface pressure (valve seat surface pressure)" acting on each valve seat 121, 122 and the "sag" of each seal member 18, 19 according to this embodiment. FIG. 9 is a graph showing the relationship between the "valve seat surface pressure" and the "leakage amount" of each seal member 18, 19 according to this embodiment. In FIGS. 8 and 9, the dashed-dotted line L1 indicates the position of the first valve seat 121, and the dashed-dotted line L2 indicates the position of the second valve seat 122. As shown in FIG. 8, the degree of "sag" of each seal member 18, 19 increases in a curved manner as the "valve seat surface pressure" exceeds a certain level. In this embodiment, the "valve seat surface pressure" at the first valve seat 121 does not cause "sag." The "valve seat surface pressure" at the second valve seat 122 causes "sag." 9, the "leakage amount" of each seal member 18, 19 decreases in a curved manner until the "valve seat surface pressure" reaches a certain level from near zero. In this embodiment, the "valve seat surface pressure" at each valve seat 121, 122 is set so that the "leakage amount" becomes zero.

[0054] [Regarding the Characteristics of the Sealing Member and the Valve Seat Convex Striation] Therefore, in this embodiment, one of a plurality of sealing members having different characteristics is selectively combined with one of a plurality of valve seat convex striations having different characteristics in order to suppress the surface pressure at the contact portion where one of the valve discs 131, 132 and the corresponding valve seat 121, 122 is higher than the other with respect to the seating load between them. That is, one characteristic is selected from a plurality of characteristics for each of the sealing members 18, 19, and one characteristic is selected from a plurality of characteristics for each of the valve seat convex striations 121 a, 122a, and each of the sealing members 18, 19 having the selected characteristic is used in combination with each of the valve seat convex striations 121 a, 122 a having the selected characteristic.

[0055] Specifically, in this embodiment, the seal members 18, 19 are essentially formed as annular plates of the same dimensions using the same rubber material. However, the second valve seat ribs 122a at the contact portions where the seating load of the valve discs 131, 132 when seated on the corresponding valve seats 121, 122 is higher based on the driving force of the actuator 15 (actuator driving force), the biasing force of the compression spring 37 (spring biasing force), the fluid pressure (fluid pressure), and the pressure loss (flow path pressure loss) in the inlet flow path 21 and the outlet flow path 221, 222 are set to have smaller radial sizes than the first valve seat ribs 121a. That is, as shown in FIG. 5 , the diameter (second rib diameter) Φ2D of the second valve seat ribs 122a is set to be smaller than the diameter (first rib diameter) Φ1D of the first valve seat ribs 121a. The heights, widths, and cross-sectional shapes of the valve seat ribs 121a, 122a are set to be the same.

[0056] Additionally, in this embodiment, the second seal member 19 at the contact portion where the seating load when the valve bodies 131, 132 seat on the corresponding valve seats 121, 122 is higher based on the actuator driving force, spring biasing force, fluid pressure, and flow path pressure loss is set to have a higher hardness than the first seal member 18. That is, the first seal member 18 is made of "ethylene propylene rubber (EPDM)," and the second seal member 19 is made of "fluororubber (FKM)," which has a smaller compression set than EPDM.

[0057] [Use Example of the Valve Device] Next, a use example of the valve device 1 according to this embodiment will be described. FIG. 10 is a circuit diagram showing a use example of the valve device 1 according to this embodiment. 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 disclosure. 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, and the like.

[0058] 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.

[0059] 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 82a 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 first piping section 90a via a first bypass piping section 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 .

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] [Regarding Functions 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, when each of the valve discs 131, 132 seats on the corresponding valve seat 121, 122, the seal members 18, 19 provided on one side of the abutment portion between each of the valve discs 131, 132 and the corresponding valve seat 121, 122 a abut against the corresponding valve seat ridge 121 a, 122 a provided on the other side. Here, in order to suppress the surface pressure at the abutment portion between the second valve disc 132 and the second valve seat 122, where the seating load between each of the valve discs 131, 132 and the corresponding valve seat 121, 122 is higher than at the other portions, the second seal member 19 and the second valve seat ridge 122 a are selectively combined with one of a plurality of seal members having different characteristics and one of a plurality of valve seat ridges having different characteristics. Therefore, at the contact points between each valve body 131, 132 and the corresponding valve seat 121, 122, the surface pressure (surface pressure applied to the second seal member 19) at the contact points between the second valve body 132 and the second valve seat 122, where the seating load is higher than the others, can be suppressed, and wear of the second seal member 19 can be suppressed.

[0066] Specifically, in this embodiment, based on the actuator driving force, the spring biasing force, the fluid pressure, and the flow path pressure loss, the second ridge diameter Φ2D is set smaller than the first ridge diameter Φ1D of the first ridge diameter Φ1D of the first ridge diameter Φ1D of the first ridge diameter Φ1D of the second ridge diameter Φ2D of the second ridge diameter Φ1D of the first ridge diameter Φ1D of the first valve seat ridge diameter Φ1D of the second valve seat ridge diameter Φ1D of the first ...

[0067] FIG. 11 is a cross-sectional view of an enlarged portion of FIG. 5 showing the relationship of fluid pressure acting on the second valve body 132 in the seated state according to this embodiment. In FIG. 11 , thick solid arrows and thick dashed arrows respectively indicate the action of fluid pressure on the second valve body 132. The fluid pressures indicated by the solid arrows are essentially canceled out by opposing pressures, and the load acting on the second valve body 132 is limited to the amount indicated by the dashed arrows. Therefore, the smaller the second ridge diameter Φ2D, the smaller the load acting on the second valve body 132. Therefore, the reduced load acting on the second valve body 132 can reduce the surface pressure (surface pressure acting on the second seal member 19) at the contact portion between the second valve body 132 and the second valve seat 122, where the seating load is higher than at other locations, thereby reducing wear and tear on the second seal member 19.

[0068] Specifically, in this embodiment, the hardness of the second seal member 19 at the contact portion where the seating load is higher is set as a physical characteristic higher than that of the first seal member 18 based on the actuator driving force, spring biasing force, fluid pressure, and flow path pressure loss. Therefore, the second seal member 19 at the contact portion where the seating load is higher has a higher hardness than the first seal member 18, and therefore deformation and strain of the second seal member 19 are reduced. Therefore, it is possible to suppress the surface pressure (surface pressure acting on the second seal member 19) at the contact portion where the seating load is higher than others, and to suppress wear of the second seal member 19.

[0069] In addition, according to the configuration of this embodiment, as a valve device 1 (82, 83) used in a cooling system 81 mounted on an electric vehicle 80, an action equivalent to the above action can be obtained, and an effect equivalent to the above effect can be obtained.

[0070] Second Embodiment Next, a valve device 1 according to a second embodiment will be described in detail with reference to Figures 12 and 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.

[0071] [Regarding the Configuration of the Seal Members] This embodiment differs from the first embodiment in the configuration of the seal members 18, 19. Fig. 12 is an enlarged cross-sectional view showing a portion of this embodiment in which the first valve body 131 is seated on the first valve seat 121. Fig. 13 is an enlarged cross-sectional view showing a portion of this embodiment in which the second valve body 132 is seated on the second valve seat 122. In this embodiment, unlike the first embodiment, as shown in Figs. 12 and 13 , the thickness T2 of the second seal member 19 at the abutment portion where the seating load when the valve bodies 131, 132 are seated on the corresponding valve seats 121, 122 is higher based on the actuator driving force, spring biasing force, fluid pressure, and flow path pressure loss is set to be larger than the thickness T1 of the first seal member 18.

[0072] [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 thickness T2 of the second seal member 19 at the abutment portion where the seating load is higher is greater than the thickness T1 of the first seal member 18, thereby mitigating stress concentration in the second seal member 19. This makes it possible to suppress the surface pressure (surface pressure acting on the second seal member 19) at the abutment portion where the seating load is higher than at other portions, and thus suppress settling of the second seal member 19.

[0073] Third Embodiment Next, a valve device 1 according to a third embodiment will be described in detail with reference to FIGS.

[0074] [Configuration of the Valve Seat Ridges] This embodiment differs from the previous embodiments in the configuration of the valve seat ribs 121a, 122a. Fig. 14 is an enlarged cross-sectional view showing a portion of the first valve body 131 seated on the first valve seat 121 according to this embodiment. Fig. 15 is an enlarged cross-sectional view showing a portion of the second valve body 132 seated on the second valve seat 122 according to this embodiment. In this embodiment, unlike the first embodiment, as shown in Figs. 14 and 15 , the second valve seat ribs 122a at the abutment portions where the seating load when the valve bodies 131, 132 seat on the corresponding valve seats 121, 122 is higher based on the actuator driving force, spring biasing force, fluid pressure, and flow path pressure loss, have a larger curvature radius R2 of the apex than the curvature radius R1 of the first valve seat ribs 121a.

[0075] Fig. 16 is a graph showing the relationship between the apex curvature radius of the valve seat ridge and the valve seat surface pressure in this embodiment. As shown in Fig. 16, the "valve seat surface pressure" of each valve seat 121, 122 decreases in a curved manner as the apex curvature radius increases.

[0076] [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 second valve seat ridge 122a at the abutment portion where the seating load is higher has a larger curvature radius R2 at its apex than the curvature radius R1 at the apex of the first valve seat ridge 121a, thereby suppressing an increase in surface pressure at the apex of the second valve seat ridge 122a. This makes it possible to suppress the surface pressure (surface pressure applied to the second seal member 19) at the abutment portion where the seating load is higher than at other portions, and thereby suppresses wear of the second seal member 19.

[0077] Fourth Embodiment Next, a valve device 1 according to a fourth embodiment will be described in detail with reference to FIGS. 17 and 18. FIG.

[0078] [Configuration of the Valve Seat Ridges] This embodiment differs from the previous embodiments in the configuration of the valve seat ribs 121a, 122a. Fig. 17 is an enlarged cross-sectional view showing a portion of the first valve body 131 seated on the first valve seat 121 according to this embodiment. Fig. 18 is an enlarged cross-sectional view showing a portion of the second valve body 132 seated on the second valve seat 122 according to this embodiment. Unlike the first embodiment, as shown in Figs. 17 and 18 , the second valve seat ribs 122a at the abutment portions where the seating load when the valve bodies 131, 132 seat on the corresponding valve seats 121, 122 is higher based on the actuator driving force, spring biasing force, fluid pressure, and flow path pressure loss are set such that the rib width W2 of the second valve seat ribs 122a is larger than the rib width W1 of the first valve seat ribs 121a.

[0079] [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 second valve seat rib 122a at the abutment portion where the seating load is higher has a rib width W2 that is larger than the rib width W1 of the first valve seat rib 121a, thereby suppressing an increase in surface pressure at the second valve seat rib 122a. This makes it possible to suppress the surface pressure (surface pressure applied to the second seal member 19) at the abutment portion where the seating load is higher than at other portions, and suppresses wear of the second seal member 19.

[0080] Fifth Embodiment Next, a valve device 1 according to a fifth embodiment will be described in detail with reference to FIGS. 19 and 20. FIG.

[0081] [Configuration of the Valve Seat Ridges] This embodiment differs from the previous embodiments in the configuration of the valve seat ribs 121a, 122a. Fig. 19 is an enlarged cross-sectional view showing a portion of this embodiment in which the first valve body 131 is seated on the first valve seat 121. Fig. 20 is an enlarged cross-sectional view showing a portion of this embodiment in which the second valve body 132 is seated on the second valve seat 122. In this embodiment, unlike the first embodiment, as shown in Figs. 19 and 20 , the second valve seat ribs 122a at the abutment portions where the seating load when the valve bodies 131, 132 are seated on the corresponding valve seats 121, 122 is higher based on the actuator driving force, spring biasing force, fluid pressure, and flow path pressure loss, have a smaller protrusion height H2 than the protrusion height H1 of the first valve seat ribs 121a.

[0082] If the protrusion height H1 of the first valve seat ridge 121a shown in Fig. 19 were the same as the protrusion height H2 of the second valve seat ridge 122a, there would be a concern that the surface pressure at the tip of the first valve seat ridge 121a would be insufficient due to variations in component tolerances, etc. In contrast, the second valve seat ridge 122a shown in Fig. 20 has a large seating load on the second valve seat 122, so the flat surface 122b adjacent to the second valve seat ridge 122a comes into surface contact with the second seal member 19, and the flat surface 122b also displaces the second seal member 19 by the amount of the increased load. This makes it possible to reduce the surface pressure of the second seal member 19 due to contact with the second valve seat ridge 122a.

[0083] [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 protrusion height H2 of the second valve seat rib 122a at the abutment portion where the seating load is higher is smaller than the protrusion height H1 of the first valve seat rib 121a, so that the seating load is borne by the second valve seat rib 122a and the surrounding flat portion 122b, and an increase in surface pressure due to the second valve seat rib 122a is suppressed. Therefore, the surface pressure (surface pressure applied to the second seal member 19) at the abutment portion where the seating load is higher than at other portions can be suppressed, and sagging of the second seal member 19 can be suppressed.

[0084] Sixth Embodiment Next, a valve device 2 according to a sixth embodiment will be described in detail with reference to FIGS. 21 and 22. FIG.

[0085] [Regarding the Configuration of the Actuator] The valve device 2 of this embodiment differs from the above-described embodiments in the configuration of the actuator 15. Fig. 21 shows a cross-sectional view of the valve device 2 in a first open state according to this embodiment. Fig. 22 shows a cross-sectional view of the valve device 2 in a second open state according to this embodiment. As shown in Figs. 21 and 22, the valve device 2, like the above-described embodiments, includes a flow path housing 11 having flow paths 21 and 22, a valve seat 12 (a first valve seat 121 and a second valve seat 122), a valve element 13 (a first valve element and a second valve element 132), a valve shaft 14, and an actuator 15, constituting a three-way valve.

[0086] The flow path housing 11 has a different form from the previous embodiments, but includes an inlet flow path 21, a first outlet flow path 221, and a second outlet flow path 222. As in the previous embodiments, the valve element 13 includes a first valve element 131 having a first seal member 18 and a second valve element 132 having a second seal member 19. The valve seats 121, 122 are formed in an annular shape separately from the flow path housing 11, are press-fitted into the inlets of the respective outlet flow paths 221, 222, and have first valve holes 16 and second valve holes 17, respectively. The relationship between the valve seats 121, 122 and the valve elements 131, 132 is an "inward-opening" type, as in the previous embodiments.

[0087] In contrast, in this embodiment, the actuator 15 is configured as a "step motor." In this embodiment, the valve shaft 14 is provided between the actuator 15 and the valve element 13 and is disposed in an assembly hole 11a formed in the flow path housing 11. A thrust bearing 51 and the like are disposed in the assembly hole 11a, centered around the valve shaft 14. Each valve element 131, 132 is fixed to the lower end of the valve shaft 14 and is adapted to abut against or separate from each valve seat 121, 122. A spring receiver 14a is integrally formed on the upper end of the valve shaft 14. A mechanical stopper 14b protruding upward is provided on the upper surface of the spring receiver 14a. In the second open state shown in FIG. 22, this mechanical stopper 14b engages with one end of a rotor body 53A (described later) to limit further rotation of the valve shaft 14.

[0088] The actuator 15 includes a stator 52 including a coil 34, a magnet rotor 53 provided inside the stator 52, and an output shaft 54 ​​provided at the center of the magnet rotor 53. These components 52 to 54 are molded and covered by a casing 35 made of resin.

[0089] The output shaft 54 ​​has a male thread 54a on its outer periphery. The lower end of the output shaft 54 ​​is connected to a spring retainer 14a provided at the upper end of the valve stem 14. The magnet rotor 53 includes a rotor body 53A and a cylindrical plastic magnet 53B integrally provided on the outer periphery of the rotor body 53A. A first radial bearing 55A is provided between the rotor body 53A and the casing 35 on the outer periphery of the upper end of the rotor body 53A. A second radial bearing 55B is provided between the plastic magnet 53B and the thrust bearing 51 on the inner periphery of the lower end of the plastic magnet 53B. These upper and lower radial bearings 55A, 55B rotatably support the magnet rotor 53 inside the stator 52. A female thread 53Aa is formed in the center of the rotor body 53A, which threads onto the male thread 54a of the output shaft 54. A first compression spring 56A is provided between the magnet rotor 53 and the lower second radial bearing 55B. A second compression spring 56B that urges the valve shaft 14 toward the magnet rotor 53 is provided between the spring receiver 14a and the second radial bearing 55B.

[0090] In the first open state shown in Fig. 21, when the magnet rotor 53 rotates in one direction, the output shaft 54 ​​makes a stroke movement in the thrust direction (upward in Fig. 21) due to the threaded relationship between the male thread 54a of the output shaft 54 ​​and the female thread 53Aa of the rotor body 53A and the biasing force of the second compression spring 56B. This stroke movement of the output shaft 54 ​​causes the valve element 13 together with the valve stem 14 to make a stroke movement in the upward direction in Fig. 21, and the first valve element 131 approaches the first valve seat 121, achieving the second open state shown in Fig. 22.

[0091] On the other hand, in the second open state shown in Fig. 22, when the magnet rotor 53 rotates in the opposite direction, the output shaft 54 ​​rotates in the opposite direction and strokes downward in Fig. 22, which is the thrust direction, against the biasing force of the second compression spring 56B, due to the threaded relationship between the male thread 54a of the output shaft 54 ​​and the female thread 53Aa of the rotor body 53A. This stroke of the output shaft 54 ​​causes the valve element 13 together with the valve stem 14 to stroke downward in Fig. 22, and the first valve element 131 separates from the first valve seat 121, achieving the first open state shown in Fig. 21.

[0092] [Regarding the function and effect of the valve device] According to the configuration of the valve device 2 of this embodiment described above, unlike the previous embodiments, the actuator 15 is configured by a step motor, but the same function and effect as the previous embodiments can be obtained.

[0093] In this embodiment, in the first open state shown in Figure 21, the second valve element 132 seats (contacts) on the second valve seat 122, restricting the movement of the valve element 13 (mechanically stopping it). This mechanical stop causes the actuator 15 (step motor) to step out, and the valve element 13 is urged upward by the second compression spring 56B. Therefore, the valve element 13 itself moves upward by the amount of step out and stops. Therefore, the second valve element 132 and the second valve seat 122 are in a state where the second valve seat ridge 122a abuts against the second seal member 19 with a certain amount of surface pressure, with a gap between them.

[0094] 22 , before the mechanical stopper 14b engages with the rotor body 53A, the first valve body 131 seats on the first valve seat 121, and the first seal member 18 of the first valve body 131 comes into contact with the flat surface of the first valve seat 121 and stops. Therefore, the surface pressure of the first valve seat 121 becomes the surface pressure when the first valve seat ridge 121a comes into contact with the first seal member 18 in a state where there is no clearance due to flat contact. Therefore, the operation of the actuator 15 increases the surface pressure of the first seal member 18, but this effect can be countered by increasing the curvature radius of the apex of the first valve seat ridge 121a.

[0095] Seventh Embodiment Next, a valve device 3 according to a seventh embodiment will be described in detail with reference to FIGS. 23 and 24. FIG.

[0096] [Configuration of the valve seats and valve discs] This embodiment differs from the previous embodiments in the configuration of the valve seats 121, 122 and the valve discs 131, 132. In the previous embodiments, a so-called inward-opening three-way valve was disclosed in which two valve discs 131, 132 were disposed in the valve chamber 20 between the two valve seats 121, 122 and were capable of seating on the corresponding valve seats 121, 122. In contrast, this embodiment discloses a so-called outward-opening three-way valve in which the two valve discs 131, 132 are not disposed in the valve chamber 20 between the two valve seats 121, 122, but are provided in the corresponding outlet flow paths 221, 222 so as to be capable of seating on the corresponding valve seats 121, 122.

[0097] Figure 23 is a cross-sectional view of the valve device 3 in a first open state according to this embodiment. Figure 24 is a cross-sectional view of the valve device 3 in a second open state according to this embodiment. As shown in Figures 23 and 24, this valve device 3, like the first to fifth embodiments, comprises a flow path housing 11 having flow paths 21, 22 (221, 222), valve seats 12 (121, 122), valve bodies 13 (131, 132), a valve stem 14, and an actuator 15.

[0098] The flow path housing 11, although having a different configuration from the other embodiments, includes an inlet flow path 21 and an outlet flow path 22 (221, 222). The valve element 13, like the above-described embodiments, includes a first valve element 131 having a first seal member 18 and a second valve element 132 having a second seal member 19, but the first seal member 18 is provided below the first valve element 131, and the second seal member 19 is provided above the second valve element 132. The valve seats 121, 122 are each formed integrally with the flow path housing 11, and each have a first valve hole 16 and a second valve hole 17. In addition, a first valve seat ridge 121a is provided above the first valve seat 121, and a second valve seat ridge 122a is provided below the second valve seat 122.

[0099] Although the arrangement of components is different, the actuator 15 includes a movable core 31, a fixed core 32, a bobbin 33, a coil 34, a compression spring 37, a casing 35, etc., similar to the first to fifth embodiments. The arrangement of the movable core 31 and the fixed core 32 is upside down compared to the first to fifth embodiments, but the seating load of the lower second valve seat 122 is greater.

[0100] 23, the spring biasing force of the expanded compression spring 37 acts upward, and a fluid pressure corresponding to the area inside the second valve seat ridge 122a acts downward on the second valve seat 122. In this case, the upward spring biasing force is greater than the downward fluid pressure, so that the second valve body 132 is maintained in a closed state.

[0101] On the other hand, in the second open state shown in Figure 24, a large spring biasing force from the compressed compression spring 37 acts upward, and a large actuator driving force acts downward. Furthermore, an upward fluid pressure corresponding to the area inside the first valve seat ridge 121a acts on the first valve seat 121. In this case, the downward actuator driving force is greater than the sum of the upward spring biasing force and the fluid pressure, so the first valve body 131 remains closed. At this time, the seating load on the first valve seat 121 is greater than the seating load on the second valve seat 122 in the first open state.

[0102] Generally, a valve device must operate by overcoming the spring force and the differential pressure across the valve body. Furthermore, since the actuator of the valve device is set to specifications that allow it to be switched to various systems, the seating load is easily affected by the actuator driving force.

[0103] [Regarding the Function and Effect of the Valve Device] According to the configuration of the valve device 3 of this embodiment described above, it is configured as an outward-opening three-way valve, unlike the inward-opening three-way valves of the previous embodiments, but it can achieve the same functions and effects as the previous embodiments.

[0104] Eighth Embodiment Next, a valve device according to an eighth embodiment will be described in detail with reference to FIGS. 25 and 26. FIG.

[0105] [Regarding the Arrangement of the Sealing Member] This embodiment differs from the above-described embodiments in the arrangement of the elastic member and the rigid member. Figure 25 is a schematic cross-sectional view of the second valve body 132 and the second valve seat 122 in the open state according to the first to sixth embodiments. Figure 26 is a schematic cross-sectional view of the second valve body 132 and the second valve seat 122 in the open state according to this embodiment. Figures 25 and 26 exemplify only the second valve seat 122 and the second valve body 132.

[0106] In each of the first to sixth embodiments, as shown in Fig. 25 , the second valve body 132 is provided with the second seal member 19 as an elastic member, and the second valve seat 122 is provided with the second valve seat ridge 122a as a rigid member so as to be able to abut against the second seal member 19. The same applies to the arrangement of the first seal member 18. In contrast, in this embodiment, as shown in Fig. 26 , the second valve seat 122 is provided with the second seal member 19 as an elastic member, and the second valve body 132 is provided with the second valve body ridge 132b as a rigid member so as to be able to abut against the second seal member 19.

[0107] [Regarding the function and effect of the valve device] According to the configuration of the valve device of this embodiment described above, the arrangement of the elastic member and the rigid member differs from that of each of the first to sixth embodiments, but basically, the same function and effect as each of the first to sixth embodiments can be obtained.

[0108] Here, the advantages of the arrangement of the elastic member and the rigid member in this embodiment will be compared with those in the first to sixth embodiments. In Figures 25 and 26, assuming that the diameters (valve hole diameters) ΦDA and ΦDB of the valve holes 17 are the same, in this embodiment, the pressure-receiving diameter ΦDPB of the tip of the second valve disc ridge 132b (rigid member) must be set with a sufficient margin in order to ensure that the second valve disc ridge 132b (rigid member) is in contact with the second seal member 19 (elastic member) while taking into account the inclination of the second valve disc 132. In contrast, in the first to sixth embodiments, the pressure-receiving diameter ΦDPA of the tip of the second valve seat ridge 122a (rigid member) does not need to be taken into account, and the pressure-receiving diameter ΦDPA of the second valve seat ridge 122a can be set smaller than the pressure-receiving diameter ΦDPB. For this reason, in each of the first to sixth embodiments, the valve opening force of the second valve body 132 due to the fluid pressure can be reduced, and the actuator 15 can be made smaller accordingly.

[0109] On the other hand, in this embodiment, the second seal member 19 (elastic member) is fixed to the periphery of the valve hole 17 of the second valve seat 122 by adhesive or baking. In contrast to this, in each of the first to sixth embodiments, the second seal member 19 can be fixed to each valve body 131, 132 by fitting. In Figures 25 and 26, "WS" indicates the width by which the second seal member 19 can absorb the tilt of the valve stem 14.

[0110] <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.

[0111] (1) In the above embodiments, the valve devices 1 to 3 are configured as three-way valves, but this is not limitative.

[0112] (2) In the above embodiments, the valve body or the valve seat is provided with a seal member as an elastic member, but the entire valve body or the valve seat may be made of an elastic member.

[0113] (3) In each of the above embodiments, the valve body or the valve seat is provided with a ridge as a rigid member, but the entire valve body or the valve seat may be made of a rigid member.

[0114] The disclosed technology can be used in fluid circuits of cooling systems mounted on electric vehicles and the like.

[0115] REFERENCE SIGNS LIST 1 valve device 2 valve device 3 valve device 12 valve seat 121 first valve seat 121a first valve seat ridge (rigid member) 122 second valve seat 122a second valve seat ridge (rigid member) 13 valve body 131 first valve body 132 second valve body 132b second valve body ridge (rigid member) 14 valve stem 15 actuator (driving unit) 18 first seal member (elastic member) 19 second seal member (elastic member) 21 inlet flow path 22 outlet flow path 221 first outlet flow path 222 second outlet flow path 37 compression spring 56B second compression spring 80 electric vehicle 81 cooling system 82 first valve device 83 second valve device Φ1D first ridge diameter Φ2D second ridge diameter T1 thickness of first seal member T2 thickness of second seal member R1: Radius of curvature at the top of the first valve seat ridge R2: Radius of curvature at the top of the second valve seat ridge W1: Width of the first valve seat ridge W2: Width of the second valve seat ridge H1: Protrusion height of the first valve seat ridge H2: Protrusion height of the second valve seat ridge

Claims

a spring that biases the valve stem in one axial direction; and an elastic member provided on one side of an abutment portion between the valve disc and the valve seat when one of the plurality of valve discs seats on one of the corresponding one of the plurality of valve seats. In this valve device, one of the plurality of elastic members having different properties is selectively combined with one of the plurality of rigid members having different properties in order to suppress the surface pressure at the abutment portion where the seating load between the valve disc and the valve seat becomes higher than in the other portions.

2. A valve device as claimed in claim 1, wherein the rigid member includes, as one of the physical characteristics, a convex rib that abuts against the corresponding elastic member, and the radial size of the convex rib at the abutment portion that applies a higher load when the valve element seats on the valve seat is smaller based on the driving force of the driving unit, the biasing force of the spring, the pressure of the fluid, and the pressure loss in the inlet flow path and the outlet flow path.

3. A valve device as claimed in claim 1, characterized in that the harder the elastic member of the contact part, the greater the load that occurs when the valve element seats on the valve seat, based on the driving force of the driving part, the biasing force of the spring, the pressure of the fluid and the pressure loss in the inlet and outlet flow paths.

4. A valve device as claimed in claim 1, characterized in that the thickness of the elastic member of the contact part is made larger as the load applied when the valve element seats on the valve seat increases based on the driving force of the driving part, the biasing force of the spring, the pressure of the fluid and the pressure loss in the inlet flow path and the outlet flow path.

5. A valve device as claimed in claim 1, wherein the rigid member includes, as one of the physical characteristics, a convex rib that abuts against the corresponding elastic member, and the curvature radius of the apex of the convex rib at the abutment portion is made larger for a convex rib at the abutment portion that applies a higher load when the valve element is seated on the valve seat based on the driving force of the driving unit, the biasing force of the spring, the pressure of the fluid, and the pressure loss in the inlet flow path and the outlet flow path.

6. A valve device as claimed in claim 1, wherein the rigid member includes, as one of the physical characteristics, a convex rib that abuts against the corresponding elastic member, and the width of the convex rib at the abutment portion is made larger as the load when the valve element seats on the valve seat increases based on the driving force of the driving unit, the biasing force of the spring, the pressure of the fluid, and the pressure loss in the inlet flow path and the outlet flow path.

7. A valve device as claimed in claim 1, wherein the rigid member includes, as one of the physical characteristics, a convex rib that abuts against the corresponding elastic member, and the protruding height of the convex rib at the abutment portion is made smaller as the load when the valve element seats on the valve seat increases based on the driving force of the driving unit, the biasing force of the spring, the pressure of the fluid and the pressure loss in the inlet flow path and the outlet flow path.

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

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