Valve device

Abstract

To provide an elastic member and a rigid member of a contact part between a valve body and a valve seat, in which a surface pressure of the contact part is suppressed where a seating load between the valve body and the valve seat becomes higher than at other parts, and fatigue of the elastic member of the contact part is suppressed.SOLUTION: A valve device 1 includes: a lead-in flow passage 21; lead-out flow passages 221, 222; valve bodies 131, 132 for switching communication and closure of the passages 21, 221, 222; valve seats 121, 122 on which corresponding valve bodies 131, 132 are seated; a valve shaft 14 which integrally moves the valve bodes 131, 132; an actuator 15 which drives the valve shaft 14; a spring 37 which urges the valve shaft 14 in one direction; seal members 18, 19 which are provided on one side of a contact part between the valve bodies 131, 132 and the valve seats 121, 122; and valve seat projections 121a, 122a which are provided on the other side of the contact part. In order to suppress a surface pressure of the contact part between the valve body 132 and the valve seat 122 in which a seating load becomes higher than other parts, the seal member 19 and the valve seat projection 122a are configured by selectively combining one of the plurality of seal members different in feature property and one of the plurality of valve seat projections different in feature property.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Conventionally, as this type of technology, for example, the technology described in Patent Document 1 below is known. This technology relates to a diverter valve (valve device) for diverting fluid, and includes an input port (introduction flow path), a first output port (first derivation flow path), a second output port (second derivation flow path), a first valve seat formed between the introduction flow path and the first derivation flow path, a second valve seat formed between the introduction flow path and the second derivation flow path, a first valve body that abuts and separates from the first valve seat, a second valve body that abuts and separates from the second valve seat, a yoke (valve shaft) to which the first valve body and the second valve body are attached, and a motor (drive unit) that drives the valve shaft, and is configured as a three-way valve.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[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. [Means for solving the problem]

[0006] In order to achieve the above object, the technology described in claim 1 is 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 gist is that one of a plurality of elastic members with different properties and one of a plurality of rigid members with different properties are selectively combined to suppress the surface pressure at the abutment portion where the seating load between the valve element and the valve seat becomes higher than at other portions.

[0007] According to the configuration of the above technology, when one of the plurality of valve bodies seats on one of the corresponding plurality of valve seats, an elastic member provided on one side of the contact portion between the valve body and the valve seat abuts against a rigid member provided on the other side. Here, in order to suppress the surface pressure at the contact portion where the seating load between the valve body and the valve seat is higher than others, one of the plurality of elastic members with different physical properties is selectively combined with one of the plurality of rigid members with different physical properties.

[0008] To achieve the above object, the technology according to claim 2 is, in the technology according to claim 1, the rigid member includes a rib that abuts against the corresponding elastic member as one of its physical properties, and based on the driving force of the driving part, the biasing force of the spring, the pressure of the fluid, and the pressure loss between the inlet passage and the outlet passage, the larger the rib of the contact portion where the load is higher when the valve body seats on the valve seat, the smaller the radial size thereof.

[0009] According to the configuration of the above technology, in addition to the action of the technology according to claim 1, the pressure of the fluid that substantially acts on the valve body corresponding to the rib of the contact portion where the load (seating load) is higher when the valve body seats on the valve seat becomes smaller.

[0010] To achieve the above object, the technology according to claim 3 is, in the technology according to claim 1, based on the driving force of the driving part, the biasing force of the spring, the pressure of the fluid, and the pressure loss between the inlet passage and the outlet passage, the higher the hardness of the elastic member of the contact portion where the load is higher when the valve body seats on the valve seat.

[0011] According to the configuration of the above technology, in addition to the action of the technology according to claim 1, since the hardness of the elastic member of the contact portion where the seating load is higher is higher, the deformation strain of the elastic member is reduced.

[0012] In order to achieve the above object, the technique according to claim 4 is, in the technique according to claim 1, based on the driving force of the driving part, the biasing force of the spring, the pressure of the fluid, and the pressure loss between the introduction flow path and the discharge flow path, the elastic member of the contact part where the load when the valve body seats on the valve seat becomes higher has a larger thickness.

[0013] According to the configuration of the above technique, in addition to the action of the technique according to claim 1, since the elastic member of the contact part where the seating load becomes higher has a larger thickness, stress concentration of the elastic member is alleviated.

[0014] In order to achieve the above object, the technique according to claim 5 is, in the technique according to claim 1, the rigid member includes a convex strip that contacts the corresponding elastic member as one of the morphological characteristics, and based on the driving force of the driving part, the biasing force of the spring, the pressure of the fluid, and the pressure loss between the introduction flow path and the discharge flow path, the convex strip of the contact part where the load when the valve body seats on the valve seat becomes higher has a larger curvature radius at its top.

[0015] According to the configuration of the above technique, in addition to the action of the technique according to claim 1, since the convex strip of the contact part where the seating load becomes higher has a larger curvature radius at its top, an increase in surface pressure at the top of the convex strip is suppressed.

[0016] In order to achieve the above object, the technique according to claim 6 is, in the technique according to claim 1, the rigid member includes a convex strip that contacts the corresponding elastic member as one of the morphological characteristics, and based on the driving force of the driving part, the biasing force of the spring, the pressure of the fluid, and the pressure loss between the introduction flow path and the discharge flow path, the convex strip of the contact part where the load when the valve body seats on the valve seat becomes higher has a larger width.

[0017] According to the configuration of the above technique, in addition to the action of the technique according to claim 1, since the convex strip of the contact part where the seating load becomes higher has a larger width, an increase in surface pressure at the convex strip is suppressed.

[0018] In order to achieve the above object, the technique according to claim 7 is, in the technique according to claim 1, the rigid member includes, as one of the morphological characteristics, a ridge that abuts against the corresponding elastic member, and based on the driving force of the driving unit, the biasing force of the spring, the pressure of the fluid, and the pressure loss between the introduction flow path and the discharge flow path, the higher the load when the valve body seats on the valve seat at the ridge of the abutting portion, the smaller the protruding height thereof.

[0019] According to the configuration of the above technique, in addition to the action of the technique according to claim 1, since the protruding height of the ridge of the abutting portion where the seating load is higher is smaller, the seating load is received by the ridge and the surrounding plane, and the increase in surface pressure at the ridge is suppressed.

[0020] In order to achieve the above object, the technique according to claim 8 is, in the technique according to any one of claims 1 to 7, the valve device is intended to be used in a cooling system mounted on an electric vehicle.

[0021] According to the configuration of the above technique, the same action as the technique according to any one of claims 1 to 7 can be obtained as a valve device used in a cooling system mounted on an electric vehicle.

Effects of the Invention

[0022] According to the technique described in claim 1, with respect to the elastic member and the rigid member provided at the contact portion between the plurality of valve bodies and the corresponding plurality of valve seats, it is possible to suppress the surface pressure at the contact portion where the seating load between the valve body and the valve seat is higher than others, and it is possible to suppress the sagging of the elastic member at the contact portion.

[0023] According to the technique described in claim 2, similar to the effect of the technique described in claim 1, it is possible to suppress the surface pressure at the contact portion where the seating load is higher than others, and it is possible to suppress the sagging of the elastic member at the contact portion.

[0024] According to the technique described in claim 3, similar to the effect of the technique described in claim 1, it is possible to suppress the surface pressure at the contact portion where the seating load is higher than others, and it is possible to suppress the sagging of the elastic member at the contact portion.

[0025] According to the technology described in claim 4, similar to the effect of the technology described in claim 1, it is possible to suppress the surface pressure at the contact portion where the seating load is higher than others, and it is possible to suppress the sagging of the elastic member at the contact portion.

[0026] According to the technology described in claim 5, similar to the effect of the technology described in claim 1, it is possible to suppress the surface pressure at the contact portion where the seating load is higher than others, and it is possible to suppress the sagging of the elastic member at the contact portion.

[0027] According to the technology described in claim 6, similar to the effect of the technology described in claim 1, it is possible to suppress the surface pressure at the contact portion where the seating load is higher than others, and it is possible to suppress the sagging of the elastic member at the contact portion.

[0028] According to the technology described in claim 7, similar to the effect of the technology described in claim 1, it is possible to suppress the surface pressure at the contact portion where the seating load is higher than others, and it is possible to suppress the sagging of the elastic member at the contact portion.

[0029] According to the technology described in claim 8, it is possible to obtain an effect equivalent to the technology described in any one of claims 1 to 7.

Brief Description of the Drawings

[0030]

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Embodiments for Carrying Out the Invention

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

[0032] <First Embodiment> First, the valve device 1 of the first embodiment will be described in detail with reference to FIGS. 1 to 11.

[0033] [Regarding the Configuration of the Valve Device] FIGS. 1 and 2 show the valve device 1 according to this embodiment in a cross-sectional view. As shown in FIGS. 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 body 13, a valve shaft 14, and an actuator 15.

[0034] This valve device 1 constitutes a three-way valve, and the flow path housing 11 includes a valve chamber 20 that houses the valve body 13, one introduction flow path 21, and two discharge flow paths 22. The valve chamber 20 constitutes one end portion of the introduction flow path 21. In this embodiment, the flow path housing 11 is formed of resin.

[0035] The introduction flow path 21 is a flow path for allowing fluid to flow into the valve chamber 20. The discharge flow path 22 is a flow path for allowing fluid to flow out from the valve chamber 20. The two discharge flow paths 22 include a first discharge flow path 221 and a second discharge flow path 222. The first discharge flow path 221 is provided on the side of the actuator 15 with respect to the valve chamber 20. The second discharge flow path 222 is provided on the side opposite to the actuator 15 with respect to the valve chamber 20.

[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 side of the first outlet flow path 221 of the valve chamber 20. The second valve seat 122 is disposed on the side of the second outlet flow path 222 of the valve chamber 20. Both the first valve seat 121 and the second valve seat 122 are formed in an annular shape and each has a first valve hole 16 and a second valve hole 17 at its center. Note that the valve seat 12 is formed of resin, but it can also be formed of rubber.

[0037] The valve body 13 is attached to the lower end of the valve shaft 14 and opens and closes the first valve hole 16 and the second valve hole 17 by coming into contact with and separating from the valve seat 12. In this embodiment, the valve body 13 includes a first valve body 131 and a second valve body 132 that are spaced apart by a distance 26 in the axial direction of the valve shaft 14. A first seal member 18 is provided at the contact portion of the first valve body 131 with the first valve seat 121, and the first seal member 18 comes into contact with and separates from the first valve seat 121. Also, a second seal member 19 is provided at the contact portion of the second valve body 132 with the second valve seat 122, and the second seal member 19 comes into contact with and separates from the second valve seat 122. Note that in this embodiment, the valve body 13 is formed of resin, but it can also be formed of metal. Each of the seal members 18, 19 is formed of rubber into an annular plate shape of the same dimension, but it can also be formed of other elastic materials.

[0038] The valve shaft 14 is disposed inside the flow path housing 11 and the actuator 15. One end side of the valve shaft 14 is disposed in the actuator 15, and the other end side of the valve shaft 14 is disposed in the valve chamber 20 where the valve body 13 is attached. The valve shaft 14 is reciprocable in the thrust direction which is its axial direction. Note that in this embodiment, the valve shaft 14 is formed of metal, but it can also be formed of resin.

[0039] The actuator 15 is a member that moves the valve shaft 14 in its axial direction together with the valve body 13, and corresponds to an example of the "drive unit" of this 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 shaft 14 and is configured to move the valve shaft 14 in its axial direction by moving in the axial direction. The fixed core 32 is disposed opposite to the movable core 31 in the axial direction of the valve shaft 14. A thrust bearing 36 for the valve shaft 14 is provided between the upper end portion of the valve shaft 14 and the fixed core 32. Further, a compression spring 37 for biasing the movable core 31 downward in FIGS. 1 and 2 is provided between the thrust bearing 36 and the movable core 31 on the outer periphery of the valve shaft 14.

[0041] The movable core 31 and the fixed core 32 are formed of a magnetic material (for example, metal). When an electric 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 the magnetic force, and the movable core 31 approaches the fixed core 32 together with the valve shaft 14 against the biasing force of the compression spring 37. When no electric 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 is separated from the fixed core 32 together with the valve shaft 14 by the biasing force of the compression spring 37.

[0042] The bobbin 33 is formed in a cylindrical shape, with the movable core 31 and the fixed core 32 provided inside and the coil 34 provided outside. By molding and covering the bobbin 33, the coil 34, etc. with resin, a resin casing 35 is formed. A connector 35a protruding laterally is integrally formed on 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 valve-opening state shown in FIG. 1 and a second valve-opening state shown in FIG. 2 by moving the valve shaft 14 in its axial direction by the actuator 15.

[0044] The "first valve-opening state" means 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 valve-opening state" means 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. Further, the "fully closed state" means a state in which the valve seat 12 and the valve body 13 are in contact with each other over the entire circumference on one end side of the annular valve seat 12, and the space between the valve seat 12 and the valve body 13 is sealed.

[0045] Here, in the first valve-opening state shown in FIG. 1, the fluid introduced from the introduction flow path 21 is led out from the first lead-out flow path 221. In the second valve-opening state shown in FIG. 2, the fluid introduced from the introduction flow path 21 is led out from the second lead-out 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 taken along line A-A of FIG. 3 of the 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 a bobbin 33 that is separate from the flow path housing 11. The bobbin 33 has a connecting portion 40 at the connection portion between the introduction flow path 21 and the first lead-out flow path 221, and the connecting portion 40 is held in the same axial direction as the valve shaft  14. That is, 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 accommodated inside the flow path housing 11 (a part of the first lead-out flow path 221).

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

[0048] [Regarding the shape of the valve element] Next, the shape of the valve element 13 of this embodiment will be described. FIG. 5 shows an enlarged cross-sectional view of the valve element 13 and the valve seat 12 of FIG. 1 according to this embodiment. As shown in FIG. 5, a predetermined interval 26 is provided between the first valve element 13 and the second valve element 132. In this interval 26, the opposing surfaces of the first valve element 131 and the second valve element 132 are flat.

[0049] As shown in FIG. 5, a first seal member 18 capable of contacting the first valve seat 121 is provided at the seating portion of the first valve element 131 with the first valve seat 121. Further, a second seal member 19 capable of contacting the second valve seat 122 is provided at the seating portion of the second valve element 132 with the second valve seat 122. Each of the seal members 18 and 19 has elasticity in nature and corresponds to an example of the "elastic member" of this disclosed technology. Each of the valve elements 131 and 132 has opposing walls 131a and 132a that converge toward the valve holes 16 and 17 of the corresponding valve seats 121 and 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, an annular first valve seat ridge 121a that can contact the first seal member 18 is formed on the valve body side opening edge of the first valve hole 16. Further, as shown in FIG. 5, an annular second valve seat ridge 122a that can contact the second seal member 19 is formed on the valve body side opening edge of the second valve hole 17. Each valve seat ridge 121a, 122a protrudes from the flat surface of the corresponding valve seat 121, 122 and is formed so as to surround each valve hole 16, 17. Each valve seat ridge 121a, 122a is, in terms of properties, more rigid than the respective seal members 18, 19 and corresponds to an example of the "rigid member" of this disclosed technology. Here, the "rigid member" means a member having higher rigidity than the "elastic member".

[0051] [Problems Regarding Seal Members] Here, problems regarding each of the seal members 18, 19 will be described. In the valve device 1 of the three-way valve of this embodiment, when each valve body 131, 132 seats on the corresponding valve seat 121, 122, the load (seating load) is 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), the driving force of the actuator 15 (actuator driving force), etc., and a difference occurs between between the first valve body 131 and the first valve seat 121 and between the second valve body 132 and the second valve seat 122. On the side where this seating load is high, the surface pressure at the contact portion between the valve bodies 131, 132 and the valve seats 121, 122 becomes high. The contact portion here is constituted by each of the seal members 18, 19 and the corresponding valve seat ridges 121a, 122a. The rubber seal members 18, 19 are excellent in sealing performance, but the surface pressure due to contact with the corresponding valve seat ridges 121a, 122a becomes high, and the higher the surface pressure, the more likely the seal members 18, 19 are to sag.

[0052] FIG. 6 shows a cross-sectional view of the fluid flow in the valve device 1 in the first valve opening state according to this embodiment. FIG. 7 shows a cross-sectional view of the fluid flow in the valve device 1 in the second valve opening state according to this embodiment. Here, for example, it is assumed that in the first valve opening state shown in FIG. 6, a high-pressure pump discharge pressure acts on the introduction passage 21, and in the second valve opening state shown in FIG. 7, a medium-pressure pump discharge pressure acts on the introduction passage 21. In this assumption, from the relationship between the fluid pressure, the spring biasing force, and the actuator driving force, in the first valve opening state, a large flow path differential pressure and the spring biasing force act on the second valve element 132, and in the second valve opening state, a medium flow path differential pressure, and the difference between the actuator driving force and the spring biasing force act on the first valve element 131. Therefore, the influence of the differential pressure before and after each valve element 131, 132 is large. In the first valve opening state, the seating load between the second valve element 132 and the second valve seat 122 becomes high, and in the second valve opening state, the seating load between the first valve element 131 and the first valve seat 121 becomes low. In this assumption, if the seal design on the premise of ensuring the sealing performance between the first valve element 131 and the first valve seat 121 is used as the specifications, the surface pressure of the contact portion between the second valve element 132 and the second valve seat 122 in the first valve opening state becomes excessive, and there is a concern that the resistance to the sag of the second seal member 19 deteriorates.

[0053] FIG. 8 shows a graph of 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 shows a graph of the relationship between the "valve seat surface pressure" and the "leakage amount" in each seal member 18, 19 according to this embodiment. The broken line L1 in FIGS. 8 and 9 indicates the position of the first valve seat 121, and the broken 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 curvilinearly as the "valve seat surface pressure" exceeds a certain height. In this embodiment, no "sag" occurs at the "valve seat surface pressure" of the first valve seat 121. "Sag" occurs at the "valve seat surface pressure" of the second valve seat 122. Also, as shown in FIG. 9, the "leakage amount" of each seal member 18, 19 decreases curvilinearly from near zero to a certain height of the "valve seat surface pressure". In this embodiment, the "valve seat surface pressure" at each valve seat 121, 122 is set so that the "leakage amount" becomes zero.

[0054] [Properties of the Seal Member and the Valve Seat Ridge] Therefore, in this embodiment, in order to suppress the surface pressure at the contact portion where one of the seating loads between each valve body 131, 132 and the corresponding valve seat 121, 122 is higher than the other, one of a plurality of seal members having different properties and one of a plurality of valve seat ridges having different properties are selectively combined and configured. That is, the property of each seal member 18, 19 is selected from a plurality of properties, the property of each valve seat ridge 121a, 122a is selected from a plurality of properties, and each seal member 18, 19 having the selected property and each valve seat ridge 121a, 122a having the selected property are combined and used.

[0055] Specifically, in this embodiment, each of the seal members 18, 19 is formed in an annular plate shape of the same size from the same rubber material in terms of properties. On the other hand, based on the driving force of the actuator 15 (actuator driving force), the biasing force of the compression spring 37 (spring biasing force), the pressure of the fluid (fluid pressure), and the pressure loss (flow path pressure loss) between the introduction flow path 21 and the discharge flow paths 221, 222, the diameter in the radial direction of the second valve seat ridge 122a of the contact portion where the seating load becomes higher when each valve body 131, 132 seats on the corresponding valve seat 121, 122 is set smaller than that of the first valve seat ridge 121a. That is, as shown in FIG. 5, the diameter (second ridge diameter) Φ2D of the second valve seat ridge 122a is set smaller than the diameter (first ridge diameter) Φ1D of the first valve seat ridge 121a. The height, width, and cross-sectional shape of each of the valve seat ridges 121a, 122a are set to be the same.

[0056] In addition, in this embodiment, based on the actuator driving force, the spring biasing force, the fluid pressure, and the flow path pressure loss, the hardness of the second seal member 19 of the contact portion where the seating load becomes higher when each valve body 131, 132 seats on the corresponding valve seat 121, 122 is set higher than that of the first seal member 18. That is, the first seal member 18 is formed of "ethylene propylene rubber (EPDM)" as the material, and the second seal member 19 is formed of "fluoroelastomer (FKM)" which has less compression set than EPDM as the material.

[0057] [Examples of Use of the Valve Device] Next, an example of using the valve device 1 of this embodiment will be described. FIG. 10 shows an example of using the valve device 1 according to this embodiment in a circuit diagram. 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 the "cooling system" of this disclosed technology. In this example of use, the refrigerant flowing through the cooling system 81 corresponds to an example of the "fluid" of this disclosure. The electric vehicle 80 is, for example, a vehicle that includes a motor driven by the power of a secondary battery as a driving source of the vehicle and travels by driving drive wheels with that motor, and includes electric vehicles, hybrid vehicles, and the like.

[0058] In this embodiment, as the valve device 1, a first valve device 82 and a second valve device 83 are included. The cooling system 81 includes, in addition to each valve device 82, 83, a heater 84, a battery 85, a DC-DC converter 86, a battery charger 87, a radiator 88, and an electric pump 89. Each valve device 82, 83 has an inlet 82a, 83a of the introduction flow path 21, a first outlet 82b, 83b of the first derivation flow path 221, and a second outlet 82c, 83c of the second derivation flow path 222. These members 82 to 89 are arranged along a main pipe 90 that circulates the refrigerant. The main pipe 90 includes a first pipe portion 90a, a second pipe portion 90b, and a third pipe portion 90c.

[0059] The discharge port 89a of the electric pump 89 is connected to the inlet 82a of the first valve device 82 via the first pipe section 90a. The second outlet 82c of the first valve device 82 is connected to the inlet 82a of the second valve device 83 via the second pipe section 90b. In the middle of the second pipe section 90b, a heater 84, a battery 85, a DC-DC converter 86, and a battery charger 87 are sequentially arranged from its upstream side. The first outlet 82b of the first valve device 82 is connected to the first pipe section 90a at the immediate upstream side of the DC-DC converter 86 via the first bypass pipe 91. The second outlet 83c of the second valve device 83 is connected to the suction port 89b of the electric pump 89 via the third pipe section 90c. A radiator 88 is arranged in the middle of the third pipe section 90c. The first outlet 83b of the second valve device 83 is connected to the third pipe section 90c at the immediate upstream side of the suction port 89b of the electric pump 89 via the second bypass pipe 92.

[0060] And in this cooling system 81, by starting the electric pump 89 and driving each valve device 82, 83 to switch the flow path, the flow of the refrigerant to each member 84 - 88 is switched.

[0061] In this embodiment, by switching the flow path by each valve device 82, 83, it is switched to the first to third flow path patterns. Here, the first flow path pattern is switched when preventing overheating and overcooling of the battery 85. In this first flow path pattern, the electric pump 89 is started and 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. Thereby, the refrigerant discharged from the electric pump 89 flows sequentially through the first bypass pipe 91, the second pipe section 90b, and the third pipe section 90c from the first valve device 82, through 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 cycle. This first flow path pattern is switched during low-speed operation in spring and autumn to keep the temperature of the battery 85 appropriate.

[0062] The second flow path pattern is switched when cooling the battery 85 or recovering waste heat for superheating. In this second flow path pattern, the electric pump 89 is activated and 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 sequentially through the first valve device 82, the second pipe section 90b, and the third pipe section 90c, 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 cycle. This second flow path pattern is switched when the temperature in summer becomes high or when the battery 85 is generating heat, and is configured to cool the battery 85.

[0063] The third flow path pattern is switched when heating the battery 85 with the heater 84. In this third flow path pattern, the electric pump 89 is activated 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 sequentially through the first valve device 82, the second pipe section 90b, the second bypass pipe 92, and the third pipe section 90c, 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 cycle. This third flow path pattern is switched when the temperature in winter becomes low or when it is desired to rapidly warm up the battery 85.

[0064] The battery 85 of the electric vehicle 80 has the characteristic that its performance deteriorates outside a certain temperature range. Therefore, in this embodiment, while monitoring the temperatures of the battery 85 and the refrigerant, the switching of the above-described flow path patterns is performed so that the temperature of the battery 85 becomes "25 to 35°C".

[0065] [Regarding the operation and effects of the valve device and the cooling system including the same] According to the configuration of the valve device 1 of this embodiment described above, when each valve element 131, 132 seats on the corresponding valve seat 121, 122, each seal member 18, 19 provided on one of the contact portions between each valve element 131, 132 and each valve seat 121, 122 abuts against the corresponding valve seat ridge 121a, 122a provided on the other. Here, in order to suppress the surface pressure at the contact portion between the second valve element 132 and the second valve seat 122 where the seating load between each valve element 131, 132 and the corresponding valve seat 121, 122 is higher than others, the second seal member 19 and the second valve seat ridge 122a are selectively combined with one of a plurality of seal members having different physical properties and one of a plurality of valve seat ridges having different physical properties. For this reason, regarding the contact portion between each valve element 131, 132 and the corresponding valve seat 121, 122, it is possible to suppress the surface pressure (the surface pressure applied to the second seal member 19) at the contact portion between the second valve element 132 and the second valve seat 122 where the seating load is higher than others, and it is possible to suppress the sagging of the second seal member 19.

[0066] Specifically, in this embodiment, the second valve seat ridge 122a of the second valve seat 122 where the seating load is higher when each valve element 131, 132 seats on the corresponding valve seat 121, 122 based on the actuator driving force, the spring biasing force, the fluid pressure, and the flow path pressure loss is set such that, as a physical property, the second ridge diameter Φ2D is smaller than the first ridge diameter Φ1D of the first valve seat ridge 121a. Therefore, the pressure of the fluid that substantially acts on the second valve element 132 corresponding to the second valve seat ridge 122a at the contact portion where the seating load is higher when each valve element 131, 132 seats on the corresponding valve seat 121, 122 becomes smaller than that of the first valve element 131.

[0067] FIG. 11 shows, according to this embodiment, the relationship of the fluid pressure acting on the second valve body 132 in the seated state by an enlarged cross-sectional view of a part of FIG. 5. In FIG. 11, the thick solid arrows and the thick dashed arrows respectively indicate the action of the fluid pressure on the second valve body 132. Here, the fluid pressures indicated by the solid arrows are substantially canceled out by the pressures acting in opposite directions, and the load acting on the second valve body 132 is only the amount indicated by the dashed arrows. Therefore, the smaller the second ridge diameter Φ2D is, the smaller the load acting on the second valve body 132 becomes. For this reason, the surface pressure (the surface pressure applied to 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 others, can be suppressed by the amount by which the load acting on the second valve body 132 is reduced, and the sag of the second seal member 19 can be suppressed.

[0068] Specifically, in this embodiment, based on the actuator driving force, the spring biasing force, the fluid pressure, and the flow path pressure loss, the higher the seating load at the contact portion where the hardness of the second seal member 19 as a characteristic property is set higher than that of the first seal member 18. Therefore, since the hardness of the second seal member 19 at the contact portion where the seating load is higher is higher than that of the first seal member 18, the deformation strain of the second seal member 19 is reduced. For this reason, the surface pressure (the surface pressure applied to the second seal member 19) at the contact portion where the seating load is higher than others can be suppressed, and the sag of the second seal member 19 can be suppressed.

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

[0070] <Second Embodiment> Next, the valve device 1 of the second embodiment will be described in detail with reference to FIGS. 12 and 13. In the following description, the same reference numerals are given to the components equivalent to those in the first embodiment, and the description thereof is omitted, and the description will be centered on the different points.

[0071] [Regarding the Configuration of the Seal Member] In this embodiment, it is different from the first embodiment in terms of the configuration of each sealing member 18, 19. FIG. 12 shows, in an enlarged cross-sectional view, a part of the seating state of the first valve element 131 with respect to the first valve seat 121 according to this embodiment. FIG. 13 shows, in an enlarged cross-sectional view, a part of the seating state of the second valve element 132 with respect to the second valve seat 122 according to this embodiment. In this embodiment, different from the first embodiment, as shown in FIGS. 12 and 13, the thickness T2 of the second sealing member 19 of the contact portion where the seating load becomes higher when each valve element 131, 132 seats on the corresponding valve seat 121, 122 based on the actuator driving force, the spring biasing force, the fluid pressure, and the flow path pressure loss is set to be larger than the thickness T1 of the first sealing member 18.

[0072] [Regarding the operation and effects of the valve device] According to the configuration of the valve device 1 of this embodiment described above, different from the first embodiment, the greater the thickness T2 of the second sealing member 19 of the contact portion where the seating load becomes higher, the larger it is than the thickness T1 of the first sealing member 18. Therefore, the stress concentration of the second sealing member 19 is alleviated. For this reason, the surface pressure (the surface pressure applied to the second sealing member 19) at the contact portion where the seating load is higher than others can be suppressed, and the sagging of the second sealing member 19 can be suppressed.

[0073] <Third Embodiment> Next, the valve device 1 of the third embodiment will be described in detail with reference to FIGS. 14 to 16.

[0074] [Regarding the configuration of the valve seat rib] In this embodiment, it is different from the above embodiments in terms of the configuration of each valve seat ridge 121a, 122a. FIG. 14 shows, in an enlarged cross-sectional view, a part of the seating state of the first valve body 131 with respect to the first valve seat 121 according to this embodiment. FIG. 15 shows, in an enlarged cross-sectional view, a part of the seating state of the second valve body 132 with respect to the second valve seat 122 according to this embodiment. In this embodiment, different from the first embodiment, as shown in FIGS. 14 and 15, the larger the radius of curvature R2 of the top of the second valve seat ridge 122a of the contact portion where the seating load increases when each valve body 131, 132 seats on the corresponding valve seat 121, 122 based on the actuator driving force, spring biasing force, fluid pressure, and flow path pressure loss, the larger the radius of curvature R2 of the top is set to be larger than the radius of curvature R1 of the first valve seat ridge 121a.

[0075] FIG. 16 shows, by a graph, the relationship between the top radius of curvature of the valve seat ridge and the valve seat surface pressure according to this embodiment. As shown in FIG. 16, it can be seen that the "valve seat surface pressure" of each valve seat 121, 122 decreases curvilinearly as the top radius of curvature increases.

[0076] [Regarding the operation and effects of the valve device] According to the configuration of the valve device 1 of this embodiment described above, different from the first embodiment, the larger the radius of curvature R2 of the top of the second valve seat ridge 122a of the contact portion where the seating load increases, the larger the radius of curvature R2 of the top is than the radius of curvature R1 of the top of the first valve seat ridge 121a. Therefore, the increase in surface pressure at the top of the second valve seat ridge 122a can be suppressed. For this reason, the surface pressure (the surface pressure applied to the second seal member 19) at the contact portion where the seating load is higher than others can be suppressed, and the sag of the second seal member 19 can be suppressed.

[0077] <Fourth Embodiment> Next, the valve device 1 of the fourth embodiment will be described in detail with reference to FIGS. 17 and 18.

[0078] [Regarding the configuration of the valve seat ridge] In this embodiment, it is different from the above embodiments in terms of the configuration of each valve seat rib 121a, 122a. FIG. 17 shows, in an enlarged cross-sectional view, a part of the seating state of the first valve body 131 with respect to the first valve seat 121 according to this embodiment. FIG. 18 shows, in an enlarged cross-sectional view, a part of the seating state of the second valve body 132 with respect to the second valve seat 122 according to this embodiment. In this embodiment, different from the first embodiment, as shown in FIGS. 17 and 18, the wider the width W2 of the second valve seat rib 122a of the contact portion where the seating load becomes higher when each valve body 131, 132 seats on the corresponding valve seat 121, 122 based on the actuator driving force, the spring biasing force, the fluid pressure, and the flow path pressure loss, the larger the width W2 is set compared to the width W1 of the first valve seat rib 121a.

[0079] [Regarding the operation and effect of the valve device] According to the configuration of the valve device 1 of this embodiment described above, different from the first embodiment, the wider the width W2 of the second valve seat rib 122a of the contact portion where the seating load becomes higher, the larger the width W2 is compared to the width W1 of the first valve seat rib 121a. Therefore, the increase in surface pressure at the second valve seat rib 122a can be suppressed. For this reason, the surface pressure (the surface pressure applied to the second seal member 19) at the contact portion where the seating load is higher than others can be suppressed, and the sagging of the second seal member 19 can be suppressed.

[0080] <Fifth Embodiment> Next, the valve device 1 of the fifth embodiment will be described in detail with reference to FIGS. 19 and 20.

[0081] [Regarding the configuration of the valve seat rib] In this embodiment, it is different from the above embodiments in terms of the configuration of each valve seat ridge 121a, 122a. FIG. 19 shows, in an enlarged cross-sectional view, a part of the seating state of the first valve body 131 on the first valve seat 121 according to this embodiment. FIG. A part of the seating state of the second valve body 132 on the second valve seat 122 according to this embodiment is shown in an enlarged cross-sectional view. In this embodiment, different from the first embodiment, as shown in FIGS. 19 and 20, based on the actuator driving force, the spring biasing force, the fluid pressure, and the flow path pressure loss, the higher the seating load when each valve body 131, 132 seats on the corresponding valve seat 121, 122, the smaller the protruding height H2 of the second valve seat ridge 122a of the contact portion is set compared to the protruding height H1 of the first valve seat ridge 121a.

[0082] Here, if the protruding height H1 of the first valve seat ridge 121a shown in FIG. 19 is made the same as the protruding height H2 of the second valve seat ridge 122a, there is a concern that the surface pressure at the tip of the first valve seat ridge 121a may be insufficient due to variations such as component tolerances. On the other hand, for the second valve seat ridge 122a shown in FIG. 20, since the seating load at the second valve seat 122 is large, the flat portion 122b adjacent to the second valve seat ridge 122a is in surface contact with the second seal member 19, so the second seal member 19 will also be displaced by the increased load at the flat portion 122b. Therefore, the surface pressure of the second seal member 19 due to contact with the second valve seat ridge 122a can be reduced.

[0083] [Regarding the operation and effects of the valve device] According to the configuration of the valve device 1 of this embodiment described above, different from the first embodiment, the higher the seating load, the smaller the protruding height H2 of the second valve seat ridge 122a of the contact portion compared to the protruding height H1 of the first valve seat ridge 121a. Therefore, the seating load is received by the second valve seat ridge 122a and the surrounding flat portion 122b, and the increase in surface pressure due to the second valve seat ridge 122a is suppressed. For this reason, the surface pressure (the surface pressure applied to the second seal member 19) at the contact portion where the seating load is higher than others can be suppressed, and the sagging of the second seal member 19 can be suppressed.

[0084] <Sixth Embodiment> Next, the valve device 2 of the sixth embodiment will be described in detail with reference to FIGS. 21 and 22.

[0085] [Configuration of the actuator] The valve device 2 of this embodiment is different from the above embodiments in terms of the configuration of the actuator 15. FIG. 21 shows a cross-sectional view of the valve device 2 in the first valve opening state according to this embodiment. FIG. 22 shows a cross-sectional view of the valve device 2 in the second valve opening state according to this embodiment. As shown in FIGS. 21 and 22, this valve device 2 includes a flow path housing 11 having respective flow paths 21 and 22, a valve seat 12 (first valve seat 121 and second valve seat 122), a valve body 13 (first valve body and second valve body 132), a valve shaft 14, and an actuator 15, and constitutes a three-way valve.

[0086] The flow path housing 11 includes an introduction flow path 21, a first derivation flow path 221, and a second derivation flow path 222, although it has a different form from the above embodiments. The valve body 13 includes a first valve body 131 having a first seal member 18 and a second valve body 132 having a second seal member 19, as in the above embodiments. Each valve seat 121, 122 is formed in an annular shape separately from the flow path housing 11, press-fitted into the inlets of the respective derivation flow paths 221, 222, and has a first valve hole 16 and a second valve hole 17, respectively. The relationship between each valve seat 121, 122 and each valve body 131, 132 is "inward opening type" as in the above embodiments.

[0087] In contrast, in this embodiment, the actuator 15 is constituted by a "stepping motor". In this embodiment, the valve shaft 14 is provided between the actuator 15 and the valve body 13 and is disposed in the mounting hole 11a formed in the flow path housing 11. Thrust bearings 51 and the like are disposed around the valve shaft 14 in the mounting hole 11a. Each of the valve bodies 131, 132 is fixed to the lower end of the valve shaft 14 and is adapted to contact or separate from each of the valve seats 121, 122. A spring receiver 14a is integrally provided at the upper end portion of the valve shaft 14. A mechanical stopper 14b protruding upward is provided on the upper surface of the spring receiver 14a. This mechanical stopper 14b engages with one end of a rotor main body 53A, which will be described later, in the second valve opening state shown in FIG. 22, and limits 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 members 52 to 54 and the like are molded and covered by a resin casing 35.

[0089] The output shaft 54 has a male thread 54a on its outer periphery. The lower end portion of the output shaft 54 is connected to the spring receiver 14a provided at the upper end portion of the valve shaft 14. The magnet rotor 53 includes a rotor main body 53A and a cylindrical plastic magnet 53B integrally provided on the outer periphery of the rotor main body 53A. A first radial bearing 55A is provided between the upper end portion outer periphery of the rotor main body 53A and the casing 35. A second radial bearing 55B is provided between the inner periphery of the lower end portion of the plastic magnet 53B and the thrust bearing 51. The magnet rotor 53 is rotatably supported inside the stator 52 by these upper and lower radial bearings 55A, 55B. A female thread 53Aa that engages with the male thread 54a of the output shaft 54 is formed at the center of the rotor main body 53A. 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 biases the valve shaft 14 toward the magnet rotor 53 is provided between the spring receiver 14a and the second radial bearing 55B.

[0090] Here, in the first valve opening state shown in FIG. 21, as the magnetic rotor 53 rotates in one direction, due to the screwing relationship between the male screw 54a of the output shaft 54 and the female screw 53Aa of the rotor main body 53A, and the biasing force of the second compression spring 56B, the output shaft 54 performs a stroke movement upward in the thrust direction shown in FIG. 21 while rotating in one direction. Due to this stroke movement of the output shaft 54, the valve body 13 together with the valve shaft 14 performs a stroke movement upward in FIG. 21, and the first valve body 131 approaches the first valve seat 121 to reach the second valve opening state shown in FIG. 22.

[0091] On the other hand, in the second valve opening state shown in FIG. 22, as the magnetic rotor 53 rotates in the opposite direction, due to the screwing relationship between the male screw 54a of the output shaft 54 and the female screw 53Aa of the rotor main body 53A, against the biasing force of the second compression spring 56B, the output shaft 54 performs a stroke movement downward in the thrust direction shown in FIG. 22 while rotating in the opposite direction. Due to this stroke movement of the output shaft 54, the valve body 13 together with the valve shaft 14 performs a stroke movement downward in FIG. 22, and the first valve body 131 moves away from the first valve seat 121 to reach the first valve opening state shown in FIG. 21.

[0092] [Regarding the operation and effect of the valve device] According to the configuration of the valve device 2 of this embodiment described above, different from the above-described embodiments, although the actuator 15 is constituted by a stepping motor, the same operations and effects as those of the above-described embodiments can be obtained.

[0093] In this embodiment, in the first valve opening state shown in FIG. 21, when the second valve body 132 seats (grounds) on the second valve seat 122, the movement of the valve body 13 is restricted (mechanically stopped). Therefore, out-of-synchronization occurs in the actuator 15 (stepping motor) in accordance with the mechanical stop, and the valve body 13 is biased upward by the second compression spring 56B. For this reason, the valve body 13 itself stops in a state where it has moved upward by the amount of out-of-synchronization. Therefore, the second valve body 132 and the second valve seat 122 are in a state with a gap, and the second valve seat rib 122a abuts against the second seal member 19 with a certain surface pressure.

[0094] In this embodiment, in the second valve opening state shown in FIG. 22, before the mechanical stopper 14b engages with the rotor main 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 contacts and stops on the plane of the first valve seat 121. For this reason, the surface pressure of the first valve seat 121 becomes the surface pressure at which the first valve seat ridge 121a contacts the first seal member 18 in a state where the gap is zero due to the plane contact. Therefore, although the operation of the actuator 15 will increase the surface pressure of the first seal member 18, this influence can be addressed by increasing the radius of curvature of the top of the first valve seat ridge 121a.

[0095] <Seventh Embodiment> Next, the valve device 3 of the seventh embodiment will be described in detail with reference to FIGS. 23 and 24.

[0096] [Configuration of Valve Seat and Valve Body] In this embodiment, it is different from the above embodiments in terms of the configuration of each valve seat 121, 122 and each valve body 131, 132. In the above embodiments, a so-called inward-opening three-way valve is disclosed in which two valve bodies 131, 132 are arranged in the valve chamber 20 between two valve seats 121, 122 and are provided so as to be seatable on the corresponding valve seats 121, 122. In contrast, in this embodiment, a so-called outward-opening three-way valve is disclosed in which two valve bodies 131, 132 are not arranged in the valve chamber 20 between two valve seats 121, 122, and each valve body 131, 132 is provided so as to be seatable on the corresponding valve seat 121, 122 in the corresponding lead-out flow paths 221, 222.

[0097] FIG. 23 shows a cross-sectional view of the valve device 3 in the first valve opening state according to this embodiment. FIG. 24 shows a cross-sectional view of the valve device 3 in the second valve opening state according to this embodiment. As shown in FIGS. 23 and 24, this valve device 3 includes a flow path housing 11 having each flow path 21, 22 (221, 222), valve seats 12 (121, 122), valve bodies 13 (131, 132), a valve shaft 14, and an actuator 15, similar to the first to fifth embodiments.

[0098] The flow path housing 11 includes an introduction flow path 21 and a discharge flow path 22 (221, 222), although it differs in form from other embodiments. The valve body 13 includes a first valve body 131 having a first seal member 18 and a second valve body 132 having a second seal member 19, similar to the above-described embodiments. However, the first seal member 18 is provided below the first valve body 131, and the second seal member 19 is provided above the second valve body 132. Each valve seat 121, 122 is integrally formed with the flow path housing 11 and has a first valve hole 16 and a second valve hole 17, respectively. Also, a first valve seat rib 121a is provided above the first valve seat 121, and a second valve seat rib 122a is provided below the second valve seat 122.

[0099] 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., although the arrangement of the components is different, 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 increased.

[0100] Here, in the first valve opening state shown in FIG. 23, the extended spring biasing force of the compression spring 37 acts upward, and a fluid pressure corresponding to the area inside the second valve seat rib 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 the closed valve state of the second valve body 132 is maintained.

[0101] On the other hand, in the second valve opening state shown in FIG. 24, the compressed large spring biasing force of the compression spring 37 acts upward, and a large actuator driving force acts downward. Also, a fluid pressure corresponding to the area inside the first valve seat rib 121a acts upward 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 closed valve state of the first valve body 131 is maintained. At this time, the seating load at the first valve seat 121 becomes greater than the seating load at the second valve seat 122 in the first valve opening state.

[0102] Generally, the valve device needs to operate by overcoming the spring biasing force and the differential pressure between the front and rear of the valve body. In addition, since the actuator of the valve device is set to be switchable for various systems, the seating load is easily affected by the actuator driving force.

[0103] [Regarding the operation and effect of the valve device] According to the configuration of the valve device 3 of this embodiment described above, although it is configured as an outward-opening three-way valve different from the inward-opening three-way valves of the above embodiments, the same operations and effects as those of the above embodiments can be obtained.

[0104] <Eighth Embodiment> Next, the valve device of the eighth embodiment will be described in detail with reference to FIGS. 25 and 26.

[0105] [Regarding the arrangement of the seal member] In this embodiment, it is different from the above embodiments in the arrangement of the elastic member and the rigid member. FIG. 25 shows a schematic cross-sectional view of the second valve body 132 and the second valve seat 122 in the valve-opening state according to the first to sixth embodiments. FIG. 26 shows a schematic cross-sectional view of the second valve body 132 and the second valve seat 122 in the valve-opening state according to this embodiment. In FIGS. 25 and 26, only the second valve seat 122 and the second valve body 132 are exemplarily shown.

[0106] In the above embodiments, as shown in FIG. 25, the second seal member 19 as an elastic member is provided on the second valve body 132, and the second valve seat rib 122a as a rigid member is provided on the second valve seat 122 so as to be able to contact the second seal member 19. The same applies to the arrangement of the first seal member 18. On the contrary, in this embodiment, as shown in FIG. 26, the second seal member 19 as an elastic member is provided on the second valve seat 122, and the second valve body rib 132b as a rigid member is provided on the second valve body 132 so as to be able to contact the second seal member 19.

[0107] [Regarding the operation and effect of the valve device] According to the configuration of the valve device of this embodiment described above, although the arrangement of the elastic member and the rigid member is different from that of each of the above embodiments, basically, the same operations and effects as those of each of the above embodiments can be obtained.

[0108] Here, the arrangement of the elastic member and the rigid member of this embodiment and that of each of the above embodiments are compared and studied in terms of advantages. Here, in FIGS. 25 and 26, when the diameters (valve hole diameters) ΦDA and ΦDB of each valve hole 17 are the same, in this embodiment, in order to ensure that the second valve body ridge 132b (rigid member) contacts the second seal member 19 (elastic member) considering the inclination of the second valve body 132, it is necessary to set the pressure-receiving diameter ΦDPB drawn by the tip of the second valve body ridge 132b with a margin. On the other hand, in each of the above embodiments, for the second valve seat ridge 122a (rigid member), it is not necessary to consider the inclination of the second valve body 132, and the pressure-receiving diameter ΦDPA drawn by the tip of the second valve seat ridge 122a can be set smaller than the pressure-receiving diameter ΦDPB. From this, in each of the above embodiments, the valve opening force of the second valve body 132 due to fluid pressure can be reduced, and the actuator 15 can be downsized accordingly.

[0109] On the other hand, in this embodiment, the second seal member 19 (elastic member) is to be fixed around the valve hole 17 of the second valve seat 122 by adhesion or baking. In contrast, in each of the above embodiments, the second seal member 19 can be fixed to each of the valve bodies 131 and 132 by fitting. In FIGS. 25 and 26, "WS" indicates the inclination absorption width of the valve shaft 14 in the second seal member 19.

[0110] <Another Embodiment> Note that the disclosed technology is not limited to the above embodiments, and a part of the configuration can be appropriately changed and implemented without departing from the spirit of the disclosed technology.

[0111] (1) In each of the above embodiments, the valve devices 1 to 3 are configured as three-way valves, but the present invention is not limited thereto.

[0112] (2) In each of the above embodiments, a sealing member is provided as an elastic member on the valve body or the valve seat, but the entire valve body or valve seat can also be constituted by an elastic member.

[0113] (3) In each of the above embodiments, a rib is provided as a rigid member on the valve body or the valve seat, but the entire valve body or valve seat can also be constituted by a rigid member.

Industrial Applicability

[0114] <{ This disclosed technology can be used in the fluid circuit of a cooling system mounted on an electric vehicle or the like.

Explanation of Reference Numerals

[0115] 1 Valve device 2 Valve device 3 Valve device 12 Valve seat 121 First valve seat 121a First valve seat rib (rigid member) 122 Second valve seat 122a Second valve seat rib (rigid member) 13 Valve body 131 First valve body 132 Second valve body 132b Second valve body rib (rigid member) 14 Valve shaft 15 Actuator (drive unit) 18 First sealing member (elastic member) 19 Second sealing member (elastic member) 21 Introduction flow path 22 Derivation flow path 221 First derivation flow path 222 Second derivation 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 rib diameter Φ2D Second rib diameter T1 Thickness of the first sealing member Thickness of the second seal member of T2 Radius of curvature at the top of the first valve seat rib of R1 Radius of curvature at the top of the second valve seat rib of R2 Width of the first valve seat rib of W1 Width of the second valve seat rib of W2 Protrusion height of the first valve seat rib of H1 Protrusion height of the second valve seat rib of H2

Claims

1. An introduction flow path, a plurality of discharge flow paths that branch from the introduction flow path in at least two directions and discharge fluid, a plurality of valve bodies that switch between communication and closure between the introduction flow path and one of the plurality of discharge flow paths, a plurality of valve seats provided corresponding to each of the plurality of discharge flow paths, on which one of the plurality of valve bodies seats, a valve shaft that integrally moves the plurality of valve bodies in the axial direction, a drive unit that drives the valve shaft in the axial direction, a spring that biases the valve shaft to one side in the axial direction, an elastic member provided on one side of the contact portion between the valve body and the valve seat and a rigid member provided on the other side when one of the plurality of valve bodies seats on one of the plurality of valve seats corresponding thereto In a valve device comprising: In order to suppress the surface pressure at the contact portion where the seating load between the valve body and the valve seat is higher than others, one of the plurality of elastic members having different property characteristics and one of the plurality of rigid members having different property characteristics are selectively combined A valve device characterized by this.

2. In the valve device according to Claim 1, The rigid member includes a rib that contacts the corresponding elastic member as one of the property characteristics, Based on the driving force of the drive unit, the biasing force of the spring, the pressure of the fluid, and the pressure loss between the introduction flow path and the discharge flow path, the larger the rib of the contact portion where the load is higher when the valve body seats on the valve seat, the smaller the radial size thereof A valve device characterized by this.

3. In the valve device according to Claim 1, Based on the driving force of the drive unit, the biasing force of the spring, the pressure of the fluid, and the pressure loss between the introduction flow path and the discharge flow path, the higher the hardness of the elastic member of the contact portion where the load is higher when the valve body seats on the valve seat A valve device characterized by this.

4. In the valve device according to Claim 1, Based on the driving force of the drive unit, the biasing force of the spring, the pressure of the fluid, and the pressure loss between the introduction flow path and the discharge flow path, the greater the thickness of the elastic member of the contact portion where the load is higher when the valve body seats on the valve seat A valve device characterized by this.

5. In the valve device according to Claim 1, The rigid member includes a rib that contacts the corresponding elastic member as one of the property characteristics, Based on the driving force of the driving unit, the biasing force of the spring, the pressure of the fluid, and the pressure loss between the introduction flow path and the discharge flow path, the larger the rib of the contact portion where the load increases when the valve body seats on the valve seat, the larger the curvature radius of its top is A valve device characterized by this.

6. In the valve device according to claim 1, As one of the characteristic properties, the rigid member includes a rib that contacts the corresponding elastic member. Based on the driving force of the driving unit, the biasing force of the spring, the pressure of the fluid, and the pressure loss between the introduction flow path and the discharge flow path, the larger the rib of the contact portion where the load increases when the valve body seats on the valve seat, the larger its width is A valve device characterized by this.

7. In the valve device according to claim 1, As one of the characteristic properties, the rigid member includes a rib that contacts the corresponding elastic member. Based on the driving force of the driving unit, the biasing force of the spring, the pressure of the fluid, and the pressure loss between the introduction flow path and the discharge flow path, the larger the rib of the contact portion where the load increases when the valve body seats on the valve seat, the smaller its protruding height is A valve device characterized by this.

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

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