Control valve

Abstract

To provide a control valve capable of downsizing itself and reducing the number of components.SOLUTION: The control valve includes a casing having an inflow port into which fluid flows from the outside and an outflow port out of which the fluid flows to the outside, and a rotor having a bottomed cylindrical valve element forming an internal space where the fluid is distributed, and stored in the casing rotatably around the axis of the valve element. In the rotor, communication / shut-off between at least one of the inflow port and the outflow port and the internal space through a communication port formed in the valve element is changed over according to the rotation position of the valve element. The casing has an axial support part slide-contacting the bottom of the valve element from the outside of the valve element in the axial direction of the valve element and rotatably supporting the valve element via the bottom.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a control valve. [Background technology]

[0002] A vehicle is equipped with a cooling system that cools a heat-generating part (e.g., an engine, a motor, etc.) by using coolant that circulates between the heat-generating part and the heat-dissipating part (e.g., a radiator, a heater, etc.). In this type of cooling system, a control valve is provided in a flow path connecting the heat-generating part and the heat-dissipating part to control the flow of coolant.

[0003] As an example of the above-mentioned control valve, Patent Document 1 below discloses a configuration including a casing having a cooling water outlet and a cylindrical rotor with a bottom that is rotatable within the casing. A communication port is formed in the cylindrical part of the rotor, which connects the inner space of the rotor with the outlet as the rotor rotates. With this configuration, the communication between the outlet and the communication port can be switched on and off by rotating the rotor. The cooling water that flows into the control valve flows through the inner space of the rotor and then flows out of the control valve through the outlet that is in communication with the communication port. As a result, the cooling water that flows into the control valve is distributed to the desired heat dissipation section in accordance with the rotation of the rotor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2020-197305 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-described conventional technology, the rotor is rotatably supported in the axial direction by a thrust bearing provided between the bottom of the rotor and the casing. Therefore, the control valve according to the conventional technology still has room for improvement in terms of reducing the number of parts. Furthermore, in the conventional technology, a portion for holding the thrust bearing must be provided in the casing, so there is still room for improvement in terms of miniaturization.

[0006] The present invention provides a control valve that can be made smaller and has a reduced number of parts. [Means for solving the problem]

[0007] In order to solve the above problems, the present disclosure employs the following aspects. A control valve according to one aspect of the present disclosure comprises a casing having an inlet through which a fluid flows in from the outside and an outlet through which the fluid flows out to the outside, and a rotor having a cylindrical valve body with a bottom that forms an internal space through which the fluid flows and that is rotatably housed within the casing around the axis of the valve body, wherein the rotor switches between communication and blocking between at least one of the inlet and outlet and the internal space through a communication port formed in the valve body depending on the rotational position of the valve body, and the casing has an axial support portion that slides against the bottom of the valve body from the outside in the axial direction of the valve body and rotatably supports the valve body via the bottom.

[0008] According to this aspect, the casing itself is provided with an axial support portion that rotatably supports the rotor, thereby reducing the number of parts compared to a configuration in which the rotor is supported by a separate thrust bearing or the like. Moreover, by supporting the bottom of the valve disc with the axial support portion, the diameter of the shaft portion can be made smaller than, for example, when a stepped surface for a thrust bearing is formed on the shaft portion of the rotor. Furthermore, the casing can be made more compact than when a portion for holding a separate thrust bearing is provided on the casing. As a result, the control valve can be made more compact.

[0009] In the above aspect, it is preferable that the axial support portion extends continuously over the entire circumference around the axis. According to this aspect, it becomes easier to stably support the rotor within the casing, and it is possible to prevent the rotor from whirling, contacting unevenly, etc. Furthermore, it is possible to prevent contaminants from entering the area radially inward from the axial support part through the gap between the axial support part and the rotor (bottom part).

[0010] In the above aspect, it is preferable that the axial support portions are provided intermittently around the axis. According to this aspect, the contact area between the axial support portion and the bottom portion can be reduced, so that wear between the axial support portion and the bottom portion can be suppressed.

[0011] In the above aspect, it is preferable that a recessed portion recessed in the axial direction relative to the axial support portion is formed in a portion of the casing that is positioned radially outward from the axial support portion. According to this aspect, a stagnation region of the fluid can be formed in the casing in a region radially outward from the axial support portion. This allows contaminants contained in the fluid to be captured before they enter the gap between the axial support portion and the bottom portion. As a result, it is possible to prevent contaminants from entering the seal accommodating portion through the gap between the axial support portion and the rotor (bottom portion).

[0012] In the above aspect, it is preferable that the casing comprises a casing body in which the inlet and the outlet are formed, and an inlet joint connected to the opening end face of the inlet of the casing body, and that the axial support portion is integrally formed with the casing body. According to this aspect, the degree of freedom in designing the axial support portion can be improved compared to, for example, forming the axial support portion in a joint, etc. This allows the axial support portion to be formed in a desired position and with a desired shape, making it easier to stably support the rotor within the casing.

[0013] In the above aspect, it is preferable that the casing includes a radial support portion that enters the internal space through the opening of the valve body and rotatably supports the cylindrical portion of the valve body from the radially inner side. According to this aspect, by providing the casing itself with a radial support portion that rotatably supports the rotor, it is possible to reduce the number of parts compared to a conventional configuration in which a sliding bearing is provided between the rotor and the casing, etc. Moreover, by rotatably supporting the valve element from the radially inner side by the radial support portion, it is possible to reduce the size of the control valve, particularly in the radial direction, compared to a configuration in which the valve element is rotatably supported from the radially outer side. Furthermore, by supporting the valve disc from the radially inner side, the radial distance from the contact point between the radial support portion and the inner peripheral surface of the valve disc to the axis can be shortened compared to when the valve disc is supported from the radially outer side. As a result, the peripheral speed on the inner peripheral surface of the valve disc can be reduced, and wear at the contact point between the radial support portion and the inner peripheral surface of the valve disc can be suppressed. Furthermore, by reducing the torque acting on the contact point, the load on the drive unit that operates the rotor can be reduced, allowing the drive unit to be smaller. [Effects of the Invention]

[0014] According to one aspect of the present invention, it is possible to achieve miniaturization and a reduction in the number of parts. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a block diagram of a cooling system according to an embodiment. [Figure 2] FIG. 2 is a perspective view of a control valve according to an embodiment. [Figure 3] FIG. 2 is an exploded perspective view of the control valve according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view corresponding to the line IV-IV in FIG. 2. [Figure 5] FIG. 5 is a cross-sectional view corresponding to the line VV in FIG. [Figure 6] FIG. 10 is an enlarged cross-sectional view of a control valve according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0016] Next, an embodiment of the present invention will be described with reference to the drawings. In the embodiments and modifications described below, corresponding components may be designated by the same reference numerals, and their description may be omitted. In the following description, expressions indicating relative or absolute arrangements, such as "parallel," "orthogonal," "center," and "coaxial," not only strictly refer to such arrangements, but also refer to a state in which there is a relative displacement with an angle or distance to the extent that tolerances or the same function are obtained. In this embodiment, "facing" does not only refer to a case in which the orthogonal directions (normal directions) of two surfaces are aligned with each other, but also includes a case in which the orthogonal directions intersect with each other.

[0017] [Cooling System 1] FIG. 1 is a block diagram of a cooling system 1. 1, the cooling system 1 is mounted on, for example, a vehicle. In this embodiment, the vehicle is not limited to one having an engine (internal combustion engine) as a vehicle drive source, but may also be an electrically powered vehicle. Electrically powered vehicles include electric vehicles, hybrid vehicles, plug-in hybrid vehicles, fuel cell vehicles, etc.

[0018] The cooling system 1 includes a heat generating unit 2, a heat dissipation unit 3, a water pump 4 (W / P), and a control valve 5 (EWV). In the cooling system 1, the coolant circulates between the heat generating unit 2 and the heat dissipation unit 3 by operating the water pump 4 and the control valve 5.

[0019] The heat generating part 2 is a part to be cooled by the coolant (a part to be absorbed by the coolant), and is a drive source of the vehicle and other heat generating parts. In the case of an electric vehicle, the heat generating part 2 includes, for example, a drive motor, a battery, a power conversion device, etc. The heat dissipation unit 3 is a component that dissipates heat from the coolant. In this embodiment, the heat dissipation unit 3 includes a radiator 8 (RAD) and a heater core 9 (HTR). Note that the heat dissipation unit 3 can be any component that has a temperature during normal operation that is lower than the temperature of the coolant after passing through the heat generation unit 2. As such a component, the heat dissipation unit 3 may be, for example, an EGR cooler that exchanges heat between EGR gas and the coolant, or a heat exchanger that exchanges heat between lubricating oil and the coolant.

[0020] The water pump 4, the heat generating unit 2, and the control valve 5 are connected in this order from upstream to downstream on the main flow path 10. In the main flow path 10, the operation of the water pump 4 causes the coolant to pass through the heat generating unit 2 and the control valve 5 in this order.

[0021] The main flow path 10 is connected to a radiator flow path 11 and an air conditioning flow path 12. A radiator 8 is provided in the radiator flow path 11. A portion of the radiator flow path 11 located upstream of the radiator 8 is connected to a control valve 5. A portion of the radiator flow path 11 located downstream of the radiator 8 is connected to a heat generating unit 2. In the radiator flow path 11, heat exchange between the coolant and outside air occurs in the radiator 8.

[0022] A heater core 9 is provided in the air conditioning flow path 12. A portion of the air conditioning flow path 12 located upstream of the heater core 9 is connected to a control valve 5. A portion of the air conditioning flow path 12 located downstream of the heater core 9 is connected to a heat generating unit 2. The heater core 9 is provided, for example, in a duct (not shown) of an air conditioner. In the air conditioning flow path 12, heat exchange occurs in the heater core 9 between the coolant and the conditioned air flowing through the duct.

[0023] In the cooling system 1, the coolant flowing into the control valve 5 by the operation of the water pump 4 is selectively supplied to at least one of the heat dissipation units 3 by the operation of the control valve 5. The coolant supplied to the heat dissipation unit 3 exchanges heat with the heat dissipation unit 3 as it passes through the heat dissipation unit 3. As a result, the coolant is cooled by the heat dissipation unit 3. The coolant that has passed through the heat dissipation unit 3 is supplied to the heat generation unit 2, and then exchanges heat with the heat generation unit 2 as it passes through the heat generation unit 2. In this way, the heat generation unit 2 is cooled by the coolant. In this way, in the cooling system 1, as the coolant circulates between the heat generation unit 2 and the heat dissipation unit 3, the coolant is cooled by the heat dissipation unit 3 while the heat generation unit 2 is cooled by the coolant. In this way, the cooling system 1 can control the heat generation unit 2 to a desired temperature.

[0024] <Control valve 5> 2 is a perspective view of the control valve 5. FIG. 3 is an exploded perspective view of the control valve 5. As shown in FIGS. 2 and 3, the control valve 5 includes a casing 21, a drive unit 22, a rotor 23, and a sealing mechanism (a first sealing mechanism 24 and a second sealing mechanism 25).

[0025] <Casing 21> The casing 21 includes a casing body 31, an inlet joint 32, a first outlet joint 33, and a second outlet joint . The casing body 31 is formed in a cylindrical shape with a bottom, having a bottom wall portion 31a and a peripheral wall portion 31b. In the following description, the direction along the axis O1 of the casing body 31 is simply referred to as the axial direction. In the axial direction, the inlet joint 32 side of the casing body 31 is referred to as the first side, and the side opposite the first side is referred to as the second side. In addition, the direction intersecting the axis O1 as viewed from the axial direction is referred to as the radial direction, and the direction around the axis O1 is referred to as the circumferential direction.

[0026] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 4, the bottom wall portion 31a is formed to a size that protrudes radially outward from the peripheral wall portion 31b. A through-hole 31c that passes through the bottom wall portion 31a in the axial direction is formed in a portion of the bottom wall portion 31a that is located on the axis O1.

[0027] In the casing body 31, the peripheral wall portion 31b is formed with an inlet 41 and a plurality of outlets (first outlet 42 and second outlet 43). The inlet 41 is an opening in the peripheral wall portion 31b that faces the first side in the axial direction. The outlets 42, 43 penetrate the peripheral wall portion 31b in the radial direction. The outlets 42, 43 are formed on the same circumference (at the same position in the axial direction) at intervals in the circumferential direction. In this embodiment, the outlets 42, 43 are formed at equal intervals in the circumferential direction. Therefore, in the illustrated example, the opening direction of the inlet 41 and the opening direction of the outlets 42, 43 are perpendicular to each other. The number of outlets may be one, or three or more. When multiple outlets are provided, they are preferably provided at equal intervals in the circumferential direction.

[0028] The inflow joint 32 is attached to the open end face of the inlet 41. The inflow joint 32 connects the main flow path 10 and the control valve 5. Specifically, the inflow joint 32 includes a joint cylinder portion 32a, a flange portion 32b, a positioning cylinder portion 32c, and a radial support portion 32d.

[0029] The joint cylindrical portion 32a extends coaxially with the axis O1. The joint cylindrical portion 32a is disposed in a state of protruding from the open end face of the inlet 41 toward a first side in the axial direction. The flange portion 32b projects radially outward from a second axial end portion of the joint cylindrical portion 32a. The flange portion 32b is fixed to the casing body 31 with screws or the like, with a packing sandwiched between the flange portion 32b and the opening end face of the inlet 41. The inlet joint 32 (flange portion 32b) may be attached to the opening end face of the inlet 41 by welding (for example, vibration welding).

[0030] The positioning cylindrical portion 32c protrudes from the flange portion 32b toward the second axial side. The positioning cylindrical portion 32c is formed in a cylindrical shape coaxial with the axis O1. The positioning cylindrical portion 32c is inserted into the inlet 41 (circumferential wall portion 31b). The positioning cylindrical portion 32c is disposed within the inlet 41 in close proximity to or in contact with the inner circumferential surface of the inlet 41 from the radially inner side. This restricts radial movement of the inlet joint 32 relative to the casing main body 31.

[0031] The radial support portion 32d protrudes from the positioning cylindrical portion 32c toward the second axial side. In the illustrated example, the radial support portion 32d protrudes to a position where it axially overlaps with a portion of the outlets 42, 43. However, the amount of protrusion of the radial support portion 32d from the positioning cylindrical portion 32c can be changed as appropriate.

[0032] The radial support portion 32d is formed in a cylindrical shape coaxial with the axis O1. That is, the radial support portion 32d extends continuously around the entire circumference in the circumferential direction. The radial support portion 32d is formed in a tapered shape such that the inner diameter gradually increases from the first side to the second side in the axial direction. Specifically, the outer diameter of the radial support portion 32d is formed uniformly over the entire axial length. In this embodiment, the outer diameter of the radial support portion 32d is larger than the outer diameter of the joint cylindrical portion 32a and smaller than the outer diameter of the positioning cylindrical portion 32c. Therefore, a gap is formed in the radial direction between the inner peripheral surface of the peripheral wall portion 31b and the outer peripheral surface of the radial support portion 32d. However, the outer diameter of the radial support portion 32d does not have to be uniform.

[0033] The inner peripheral surface of the radial support portion 32d is formed with an inclined surface 32f that extends radially outward from the first axial side to the second axial side. In this embodiment, the inclined surface 32f is formed continuously over a range extending to the inner peripheral surface of the positioning cylindrical portion 32c. However, the inclined surface 32f may be formed only on the radial support portion 32d, or may be formed up to the joint cylindrical portion 32a. The inner diameter of the radial support portion 32d may also be uniform.

[0034] The first outlet joint 33 is attached to the open end face of the first outlet 42. The first outlet joint 33 connects, for example, the radiator 8 (radiator flow path 11) and the control valve 5. Specifically, the first outlet joint 33 includes a joint tubular portion 51, a flange portion 52, and a positioning tubular portion 53.

[0035] The joint cylindrical portion 51 is disposed so as to protrude radially outward from the open end face of the first outlet 42. In the following description, the direction along the axis O2 of the joint cylindrical portion 51 may be referred to as the joint axial direction, the direction intersecting the joint axial direction as viewed from the joint axial direction may be referred to as the joint radial direction, and the direction around the axis O2 may be referred to as the joint circumferential direction.

[0036] The joint cylindrical portion 51 is formed in a multi-stage cylindrical shape with a diameter that decreases toward the outside in the joint axial direction (away from the casing main body 31). Specifically, the joint cylindrical portion 51 includes a small diameter portion 55 and a large diameter portion 56 that is continuous with the small diameter portion 55 toward the inside in the joint axial direction (approaching the casing main body 31). The flange portion 52 projects outward in the radial direction of the joint from the large diameter portion 56. The flange portion 52 is fixed to the casing body 31 with screws or the like, with a packing sandwiched between the flange portion 52 and the opening end face of the first outlet 42. The first outlet joint 33 (flange portion 52) may be attached to the opening end face of the first outlet 42 by welding (for example, vibration welding, etc.).

[0037] The positioning cylindrical portion 53 protrudes inward in the joint axial direction from the inner peripheral edge of the flange portion 52. The positioning cylindrical portion 53 is formed in a cylindrical shape coaxial with the axis O2. The inner diameter of the positioning cylindrical portion 53 is equal to the inner diameter of the large diameter portion 56. The positioning cylindrical portion 53 is inserted into the first outflow port 42. The positioning cylindrical portion 53 is arranged in the first outflow port 42 in close proximity to or in contact with the inner peripheral surface of the first outflow port 42 from the inside in the joint radial direction. This restricts movement of the first outflow joint 33 relative to the casing main body 31 in the joint radial direction.

[0038] The second outflow joint 34 is attached to the open end face of the second outlet 43. The second outflow joint 34 connects, for example, the heater core 9 (air conditioning flow path 12) and the control valve 5. The second outflow joint 34 has the same configuration as the first outflow joint 33. Therefore, the components of the second outflow joint 34 that correspond to the first outflow joint 33 are given the same reference numerals as the first outflow joint 33, and a description of the second outflow joint 34 will be omitted.

[0039] <Drive unit 22> The drive unit 22 is attached to the bottom wall portion 31a. The drive unit 22 is configured to house a motor, a speed reduction mechanism, a control board, etc., which are not shown.

[0040] <Rotor 23> The rotor 23 is accommodated in the casing 21 so as to be rotatable about an axis O1. The rotor 23 includes a shaft portion 23a and a valve body 23b. The shaft portion 23a is disposed coaxially with the axis O1. The shaft portion 23a penetrates the bottom wall portion 31a through the through-hole 31c. A second axial end of the shaft portion 23a is connected to the drive unit 22 outside the casing 21. This allows the power of the drive unit 22 to be transmitted to the rotor 23 via the shaft portion 23a.

[0041] The valve body 23b is formed in a cylindrical shape with a bottom that opens toward a first side in the axial direction and is disposed coaxially with the axis O1. The space of the valve body 23b that is surrounded by the bottom portion 61 and the cylindrical portion 62 constitutes an internal space K1 of the valve body 23b. That is, the internal space K1 communicates with the inside of the casing 21 through an opening in the cylindrical portion 62 that faces the first side in the axial direction.

[0042] A bottom portion 61 of the valve body 23b projects radially outward from the first axial end portion of the shaft portion 23a. The cylindrical portion 62 of the valve body 23b extends from the outer peripheral edge of the bottom portion 61 to the first side in the axial direction. The cylindrical portion 62 extends beyond the outlet ports 42, 43 to the first side in the axial direction.

[0043] A communication port 62a is formed in the cylindrical portion 62 at the same axial position as each of the outlets 42, 43. The communication port 62a penetrates the cylindrical portion 62 in the radial direction. When the communication port 62a and one of the outlets 42, 43 at least partially overlap each other as viewed in the radial direction, the valve body 23b communicates one of the outlets 42, 43 with the internal space K1 through the communication port 62a. In this embodiment, two communication ports 62a are formed at intervals in the circumferential direction. In the illustrated example, the minor angle of the conjugate angles formed by the straight lines connecting the axis O1 and each of the communication ports 62a is greater than 90° and less than 180°. However, the number of communication ports 62a and the spacing between adjacent communication ports 62a can be changed as appropriate.

[0044] Here, the rotor 23 is rotatably housed within the casing 21, with the rotor 23 being supported by the radial support portion 32d in the cylindrical portion 62 from the radially inner side and the axial support portion 65 in the bottom portion 61 from the second axial side. Specifically, the radial support portion 32d is inserted into the cylindrical portion 62 through an opening facing the first axial side of the cylindrical portion 62. The radial support portion 32d is in proximity to or in contact with the inner circumferential surface of the cylindrical portion 62 from the radially inner side at the first axial end portion of the cylindrical portion 62. As a result, the radial support portion 32d restricts radial movement of the rotor 23 relative to the casing 21. As the rotor 23 rotates, the inner circumferential surface of the cylindrical portion 62 slides against the radial support portion 32d, thereby rotatably supporting the rotor 23. Note that the amount of penetration of the radial support portion 32d into the cylindrical portion 62 can be changed as appropriate. In the illustrated example, the radial support portion 32d does not overlap the communication port 62a when viewed from the radial direction, and extends to a position where it overlaps with part of the seal mechanisms 24, 25 (sliding ring 71 described later).

[0045] The axial support portion 65 protrudes toward a first axial side from a portion of the bottom wall portion 31a that overlaps with the bottom portion 61 when viewed in the axial direction. The axial support portion 65 is disposed coaxially with the axis O1 and is formed in a cylindrical shape that surrounds the periphery of the shaft portion 23a. In other words, the axial support portion 65 extends continuously around the entire circumferential direction.

[0046] The first axial end surface of the axial support portion 65 is formed as a flat surface perpendicular to the axial direction. The axial support portion 65 is in proximity to or in contact with the outer end surface (the end surface facing the second axial side) of the bottom portion 61 from the second axial side. As a result, the axial support portion 65 restricts movement of the rotor 23 toward the second axial side relative to the casing 21. As the rotor 23 rotates, the outer end surface of the bottom portion 61 slides against the axial support portion 65, rotatably supporting the rotor 23. Preferably, the axial support portion 65 faces the outer end surface of the bottom portion 61 at an outer peripheral portion of the outer end surface. In the illustrated example, the axial support portion 65 faces the outer end surface of the bottom portion 61 at a portion that is radially outward of a point where the radius of the bottom portion 61 is divided internally at a ratio of 1:1 and radially inward of the inner peripheral surface of the cylindrical portion 62.

[0047] A seal accommodating portion 66 is formed in a portion of the bottom wall portion 31a that is located radially inward relative to the axial support portion 65. The seal accommodating portion 66 is a recess that opens toward a first side in the axial direction. A through hole 31c opens on the bottom surface of the seal accommodating portion 66. A lip seal 67 is fitted into the seal accommodating portion 66. The lip seal 67 is an annular member that is U-shaped in cross section. The lip seal 67 provides a seal between the outer peripheral surface of the shaft portion 23a and the inner peripheral surface of the seal accommodating portion 66 within the seal accommodating portion 66.

[0048] A recessed portion 68 is formed in a portion of the bottom wall portion 31a that is located radially outward from the axial support portion 65. The recessed portion 68 forms a stagnant area for the coolant, thereby capturing contaminants contained in the coolant before they enter between the axial support portion 65 and the bottom portion 61. The recessed portion 68 is recessed toward the second axial side with respect to the axial support portion 65 and is formed as a groove that extends around the entire circumferential direction. Of the inner surfaces of the recessed portion 68, the surface facing radially inward is formed by the inner circumferential surface of the peripheral wall portion 31b. On the other hand, of the inner surfaces of the recessed portion 68, the surface facing radially outward is formed by the outer circumferential surface of the axial support portion 65.

[0049] <First sealing mechanism 24 and second sealing mechanism 25> The first sealing mechanism 24 is provided in the area surrounded by the first outflow joint 33 and the first outlet 42, and seals between the first outflow joint 33 and the valve body 23b (cylindrical portion 62). The second sealing mechanism 25 is provided in the area surrounded by the second outflow joint 34 and the second outlet 43, and seals between the second outflow joint 34 and the valve body 23b (cylindrical portion 62). Note that since both sealing mechanisms 24, 25 have the same configuration, the first sealing mechanism 24 will be described as an example.

[0050] FIG. 5 is a cross-sectional view taken along line VV in FIG. As shown in FIG. 5, the first seal mechanism 24 includes a sliding ring 71, a biasing member 72, and a seal ring 73. The sliding ring 71 is inserted into the first outlet 42. The sliding ring 71 extends coaxially with the axis O2 and is formed in a multi-stage cylindrical shape whose diameter decreases toward the outside in the joint axial direction. Specifically, the sliding ring 71 includes a large diameter portion 71a and a small diameter portion 71b that continues from the large diameter portion 71a toward the outside in the joint axial direction.

[0051] The large diameter portion 71a is disposed within the first outlet 42, in proximity to or in contact with the inner circumferential surface of the first outlet 42 from the inside in the joint radial direction. This restricts movement of the sliding ring 71 in the joint radial direction relative to the casing body 31. The inner end surface of the large diameter portion 71a in the joint axial direction forms a sliding surface 71c. The sliding surface 71c is formed in an arc shape that extends following the outer circumferential surface of the cylindrical portion 62 when viewed in the axial direction. The sliding surface 71c slides on the outer circumferential surface of the cylindrical portion 62 as the rotor 23 and the sliding ring 71 rotate relative to each other.

[0052] The outer peripheral surface of the small diameter portion 71b is continuous with the outer peripheral surface of the large diameter portion 71a via a stepped surface 71d. The stepped surface 71d slopes outward in the joint radial direction as it extends inward in the joint axial direction, and then extends further outward in the joint radial direction. Therefore, a gap in the joint radial direction (hereinafter referred to as a seal gap Q) is provided between the outer peripheral surface of the small diameter portion 71b and the inner peripheral surface of the first outlet 42. Meanwhile, the inner peripheral surface of the small diameter portion 71b smoothly connects to the inner peripheral surface of the large diameter portion 71a. The outer end surface of the small diameter portion 71b in the joint axial direction (hereinafter referred to as seat surface 71f) is formed into a flat surface perpendicular to the joint axial direction. Seat surface 71f is located at the same position as the opening end surface of the first outlet 42 in the joint axial direction.

[0053] The biasing member 72 is disposed between the sliding ring 71 and the first outlet joint 33. The biasing member 72 is, for example, a wave spring. An inner end of the biasing member 72 in the joint axial direction abuts against the seat surface 71f. An outer end of the biasing member 72 in the joint axial direction abuts against a step surface between the small diameter portion 55 and the large diameter portion 56 of the first outlet joint 33. As a result, the biasing member 72 biases the sliding ring 71 inward in the joint axial direction (toward the outer peripheral surface of the tubular portion 62).

[0054] The seal ring 73 is, for example, a Y-shaped packing. The seal ring 73 surrounds the sliding ring 71 (small diameter portion 71b) with its opening (forked portion) facing inward in the joint axial direction. Specifically, when the seal ring 73 is disposed in the seal gap Q, the tip ends of the forked portion are in close contact with the outer circumferential surface of the small diameter portion 71b and the inner circumferential surface of the first outlet 42, respectively. Within the seal gap Q, the hydraulic pressure of the casing 21 is introduced to the inner region of the seal ring 73 in the joint axial direction through the gap between the inner circumferential surface of the first outlet 42 and the sliding ring 71. In this case, the stepped surface 71d faces the sliding surface 71c on the sliding ring 71 in the joint axial direction and constitutes a pressure-receiving surface that is pressed inward in the joint axial direction by the hydraulic pressure in the casing 21.

[0055] In the sliding ring 71, the area S1 of the step surface 71d and the area S2 of the sliding surface 71c are set to satisfy the following formulas (1) and (2). S1 <S2≦S1 / k …(1) α≦k<1 …(2) k: Pressure decrease constant of the coolant flowing through the minute gap between the sliding surface 71c and the cylindrical portion 62 α: Lower limit of pressure decrease constant determined by the physical properties of the coolant The area S1 of the step surface 71d and the area S2 of the sliding surface 71c refer to the areas when projected in the joint axis direction.

[0056] In equation (2), α is the standard value of the pressure reduction constant, which is determined by the type of coolant and the operating environment (e.g., temperature). For example, under normal operating conditions, α = 1 / 2 for water. If the physical properties of the coolant used change, α will change to 1 / 3, etc. Furthermore, the pressure reduction constant k in equation (2) is a standard value of α (for example, ½) when the sliding surface 71c is in uniform contact with the cylindrical portion 62 from the outer edge to the inner edge in the radial direction of the joint. However, due to manufacturing errors, assembly errors, etc. of the sliding ring 71, the gap between the outer peripheral portion of the sliding surface 71c and the cylindrical portion 62 may be slightly larger than the gap between the inner peripheral portion of the sliding surface 71c. In this case, the pressure reduction constant k in equation (2) gradually approaches k=1.

[0057] In this embodiment, assuming that there is a small gap between the sliding surface 71c of the sliding ring 71 and the outer peripheral surface of the cylindrical portion 62 to allow sliding, the relationship between the areas S1 and S2 of the step surface 71d and the sliding surface 71c is determined by equations (1) and (2). That is, the pressure of the coolant inside the casing 21 acts directly on the step surface 71d. On the other hand, the pressure of the coolant inside the casing 21 does not act directly on the sliding surface 71c. Specifically, the pressure of the coolant acts while decreasing as the coolant flows from the outer edge toward the inner edge in the joint radial direction through the minute gap between the sliding surface 71c and the cylindrical portion 62. At this time, the pressure of the coolant gradually decreases toward the inside in the joint radial direction, and tries to push the sliding ring 71 outward in the joint axial direction.

[0058] As a result, a force obtained by multiplying the area S1 of the step surface 71d by the pressure P inside the casing 21 acts directly on the step surface 71d. On the other hand, a force obtained by multiplying the area S2 of the sliding surface 71c by the pressure P inside the casing 21 and a pressure reduction constant k acts on the sliding surface 71c.

[0059] In the control valve 5 of this embodiment, the areas S1 and S2 are set so that k×S2≦S1 holds, as is clear from equation (1). Therefore, the relationship P×k×S2≦P×S1 also holds. Therefore, the force F1 (F1=P×S1) acting on the step surface 71d of the sliding ring 71 in the pressing direction is greater than or equal to the force F2 (F2=P×k×S2) acting on the sliding surface 71c of the sliding ring 71 in the lifting direction. Therefore, in the control valve 5 of this embodiment, the gap between the sliding ring 71 and the cylindrical portion 62 can be sealed only by the relationship in the pressure of the coolant inside the casing 21.

[0060] On the other hand, in this embodiment, the area S1 of the stepped surface 71d is smaller than the area S2 of the sliding surface 71c. Therefore, even if the pressure of the coolant in the casing 21 increases, it is possible to prevent the sliding surface 71c from being pressed against the cylindrical portion 62 with excessive force. Therefore, when the control valve 5 of this embodiment is used, it is possible to avoid an increase in the size and output of the drive unit 22 that rotationally drives the rotor 23, and it is also possible to prevent early wear of the radial support portion 32d, the axial support portion 65, and the sliding ring 71.

[0061] As described above, in this embodiment, the area S2 of the sliding surface 71c is set to be larger than the area S1 of the stepped surface 71d within a range in which the inward pressing force in the joint axis direction acting on the sliding ring 71 is not smaller than the outward lifting force in the joint axis direction acting on the sliding ring 71. Therefore, the sliding ring 71 and the cylindrical portion 62 can be sealed while preventing the sliding ring 71 from being pressed against the cylindrical portion 62 with excessive force.

[0062] [Operation of control valve 5] Next, the operation of the control valve 5 will be described. As shown in Fig. 1, in the main flow path 10, the coolant pumped out by the water pump 4 undergoes heat exchange in the heat generating unit 2 and then flows toward the control valve 5. As shown in Fig. 4, the coolant that has passed through the heat generating unit 2 in the main flow path 10 flows into the internal space K1 through the inlet joint 32. The coolant that has flowed into the internal space K1 fills the entire interior of the casing body 31 through the communication port 62a, the gap between the rotor 23 and the inlet joint 32, and the like.

[0063] Next, a method for distributing the coolant in the control valve 5 will be described. When the communication port 62a and the outlets 42, 43 do not overlap when viewed from the radial direction, communication between the internal space K1 and the outlets 42, 43 (outlet joints 33, 34) through the sliding ring 71 is blocked (blocked state). In the blocked state, the coolant in the internal space K1 is restricted from flowing into the outlets 42, 43 through the communication port 62a.

[0064] For example, when it is desired to supply coolant to the radiator 8, the communication port 62a and the first outlet 42 are communicated with each other. Specifically, the drive unit 22 is driven to rotate the rotor 23 around the axis O1. At this time, the rotor 23 rotates around the axis O1 while the sliding ring 71 (sliding surface 71c) slides on the outer circumferential surface of the cylindrical portion 62. Then, at least a portion of the communication port 62a and the inside of the sliding ring 71 overlap each other when viewed from the radial direction, so that the communication port 62a and the first outlet 42 are communicated with each other (communicating state). In the communicating state, the coolant in the internal space K1 flows out through the communication port 62a. The coolant flowing out of the internal space K1 passes through the first outlet 42 through the sliding ring 71, and is then distributed to the radiator flow path 11 through the first outlet joint 33. The coolant distributed to the radiator flow path 11 passes through the radiator 8, then returns to the main flow path 10, and flows into the control valve 5 again.

[0065] On the other hand, when it is desired to supply coolant to the heater core 9, the communication port 62a is connected to the second outlet 43 in the same manner as described above. As a result, the coolant flowing out from the internal space K1 passes through the sliding ring 71 and the second outlet 43, and then passes through the second outlet joint 34 and is distributed to the air conditioning flow path 12. In this way, in the control valve 5 of this embodiment, communication between the internal space K1 and the outlets 42, 43 through the communication port 62a is switched on and off depending on the rotational position of the rotor 23. This allows the coolant to be distributed to desired flow paths.

[0066] In the control valve 5 of this embodiment, the casing 21 is configured to be in sliding contact with the bottom 61 of the valve body 23b from the second axial side and to be provided with an axial support portion 65 that rotatably supports the rotor 23 via the bottom 61. According to this configuration, the casing 21 itself includes the axial support portion 65 that rotatably supports the rotor 23. This reduces the number of parts compared to a configuration in which the rotor 23 is supported by a separate thrust bearing or the like. Furthermore, by supporting the bottom portion 61 of the valve body 23b with the axial support portion 65, the diameter of the shaft portion 23a can be reduced compared to a case in which a stepped surface for a thrust bearing is formed on the shaft portion. Furthermore, the casing 21 can be made more compact compared to a case in which a portion for holding a separate thrust bearing is provided on the casing. As a result, the control valve 5 can be made more compact. Furthermore, by reducing the diameter of the shaft portion 23a, the radial distance from the contact point between the shaft portion 23a and a sliding portion (e.g., the lip seal 67 or the inner peripheral surface of the through hole 31c) and the axis O1 can be shortened. As a result, the peripheral speed on the outer peripheral surface of the shaft portion 23a can be reduced, and wear at the contact point between the shaft portion 23a and the sliding portion (e.g., the lip seal 67 or the inner peripheral surface of the through hole 31c) and the shaft portion 23a can be reduced. Furthermore, by reducing the torque acting on the contact point, the load on the drive unit 22 can be reduced, allowing the drive unit 22 to be made smaller.

[0067] In the control valve 5 of this embodiment, the axial support portion 65 is configured to extend continuously over the entire circumference around the axis O1. This configuration makes it easier to stably support the rotor 23 within the casing 21, and can prevent whirling, uneven contact, etc. of the rotor 23. It also makes it possible to prevent contaminants, etc. from entering the seal accommodating portion 66 through the gap between the axial support portion 65 and the rotor 23 (bottom portion 61).

[0068] In the control valve 5 of this embodiment, a recess 68 that is recessed in the axial direction relative to the axial support portion 65 is formed in a portion of the casing 21 that is located radially outward from the axial support portion 65. According to this configuration, a stagnation region of the coolant can be formed in the casing 21 in an area radially outward from the axial support portion 65. This makes it possible to capture contaminants contained in the coolant before they enter between the axial support portion 65 and the bottom portion 61. As a result, it is possible to prevent contaminants from entering the seal accommodating portion 66 through the gap between the axial support portion 65 and the rotor 23 (bottom portion 61).

[0069] In the control valve 5 of this embodiment, the axial support portion 65 is integrally formed with the casing body 31. This configuration improves the degree of freedom in designing the axial support portion 65 compared to when the axial support portion 65 is formed in a joint or the like. This allows the axial support portion 65 to be formed in a desired position and with a desired shape, making it easier to stably support the rotor 23 inside the casing 21.

[0070] In the control valve 5 of this embodiment, the casing 21 enters the internal space K1 through an opening facing the first axial side in the valve body 23b, and is configured to include a radial support portion 32d that rotatably supports the valve body 23b from the radial inside. According to this configuration, the casing 21 itself is provided with the radial support portion 32d that rotatably supports the rotor 23, thereby reducing the number of parts compared to a conventional configuration in which a sliding bearing is provided between the rotor and the casing. Moreover, by rotatably supporting the rotor 23 from the radially inner side by the radial support portion 32d, the control valve 5 can be made smaller, particularly in the radial direction, compared to a configuration in which the rotor is rotatably supported from the radially outer side. Furthermore, by supporting the rotor 23 from the radially inner side, the radial distance from the contact point between the radial support portion 32d and the inner circumferential surface of the cylindrical portion 62 to the axis O1 can be made shorter compared to when the rotor 23 is supported from the radially outer side. As a result, the circumferential speed on the inner circumferential surface of the cylindrical portion 62 can be reduced, and wear at the contact point between the radial support portion 32d and the inner circumferential surface of the cylindrical portion 62 can be suppressed. Furthermore, by reducing the torque acting on the contact point, the load on the drive unit 22 can be reduced, allowing the drive unit 22 to be made smaller.

[0071] (Variation) In the above-described embodiment, the axial support portion 65 extends continuously around the entire circumference, but the present invention is not limited to this configuration. As in the control valve 5 shown in FIG. 6, the axial support portion 65 may be provided intermittently in the circumferential direction. According to this configuration, the contact area between the axial support portion 65 and the bottom portion 61 can be reduced, and therefore wear between the axial support portion 65 and the bottom portion 61 can be suppressed.

[0072] (Other variations) Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Addition, omission, substitution, and other modifications of the configuration are possible without departing from the spirit of the present invention. The present invention is not limited by the above description, but is limited only by the appended claims. For example, in the above embodiment, the control valve 5 is mounted in the cooling system 1 of the vehicle, but the present invention is not limited to this configuration and may be mounted in other systems. In the above-described embodiment, the coolant flowing into the control valve 5 is distributed to the radiator flow path 11 and the air conditioning flow path 12, but the present invention is not limited to this configuration. The control valve 5 may be configured to distribute the coolant flowing into the control valve 5 to multiple flow paths.

[0073] In the above-described embodiment, the configuration in which the inlet 41 faces the axial direction and the outlets 42 and 43 face the radial direction has been described, but the configuration is not limited to this. For example, the configuration may be such that the outlet faces the axial direction and the inlet faces the radial direction, or such that all of the inlet and outlet face the axial direction or the radial direction. Furthermore, in a configuration in which the inlets or outlets face in the radial direction, the inlets or outlets do not have to be located on the same circumference but may be located at different positions in the axial direction. When the inlets or outlets are unevenly arranged in the circumferential direction, bosses or the like that support the rotor 23 (tubular portion 62) may be provided in a portion of the casing 21 that is located on the same circumference as the inlets or outlets. In this case, by arranging the inlets, outlets, or bosses that are located on the same circumference at equal intervals, it becomes easier to stably support the rotor 23 within the casing 21, and whirling, uneven contact, etc. of the rotor 23 can be suppressed.

[0074] In the above-described embodiment, the opening of the casing body 31 (peripheral wall portion 31b) functions as the inlet 41, but the present invention is not limited to this configuration. The inlet and outlet may be formed in the bottom wall portion 31a of the casing body 31. In this case, a communication port may be formed in the bottom portion 61 of the rotor 23. In the above-described embodiment, a configuration has been described in which the inlet 41 is constantly in communication with the internal space K1, but the present invention is not limited to this configuration. The inlet 41 may also be configured to be able to switch between communication and cut-off with the internal space K1 in accordance with the rotation of the rotor 23. In other words, the control valve according to the present invention may be configured in such a way that communication and cut-off between at least one of the inlet and the outlet and the internal space can be switched through a communication port formed in the valve body in accordance with the rotational position of the valve body.

[0075] In the above-described embodiment, the axial support portion 65 protrudes in the axial direction from the bottom wall portion 31a, but the present invention is not limited to this configuration. The axial support portion may be formed on the inner surface of the casing 21, and a protrusion or the like may be formed that protrudes from the rotor 23 (for example, the bottom portion 61 or the cylindrical portion 62) toward the axial support portion and slides on the axial support portion. In the above-described embodiment, the rotor 23 and the outlet port are sealed via a sealing mechanism, but the present invention is not limited to this configuration. For example, the inner circumferential surface of the casing body 31 and the rotor 23 (the cylindrical portion 62) may slide directly against each other to seal the gap between the casing body 31 and the rotor 23.

[0076] In the above-described embodiment, the axial support portion 65 is integrally formed with the casing body 31, but the present invention is not limited to this configuration. The axial support portion 65 may be integrally formed with the inlet joint 32 or the outlet joints 33 and 34. In the above-described embodiment, the radial support portion 32d is integrally formed with the casing 21, but the present invention is not limited to this configuration. A sliding bearing or the like separate from the casing 21 may be provided to support the rotor 23 in the radial direction.

[0077] In the above-described embodiment, the rotor 23 (the cylindrical portion 62) and the casing 21 (the peripheral wall portion 31b) are each formed in a cylindrical shape (with a uniform diameter throughout the axial direction). However, this configuration is not limiting. That is, as long as the cylindrical portion 62 is configured to be rotatable within the peripheral wall portion 31b, the outer diameter of the cylindrical portion 62 and the inner diameter of the peripheral wall portion 31b may be varied in the axial direction. In this case, the cylindrical portion 62 and the peripheral wall portion 31b may be formed in various shapes, such as a spherical shape (a shape in which the diameter decreases from the center toward both ends in the axial direction), a shape in which multiple spherical shapes are connected in the axial direction, a tapered shape (a shape in which the diameter gradually changes from the first side to the second side in the axial direction), or a stepped shape (a shape in which the diameter gradually changes from the first side to the second side in the axial direction).

[0078] In addition, within the scope of the spirit of the present invention, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described modified examples may be combined as appropriate. [Explanation of symbols]

[0079] 5: Control valve 21: Casing 23: Rotor 23b: Valve body 31: Casing body 32: Inlet joint 32d: Radial support part 41:Inlet 42: 1st outlet (outlet) 43:Second outlet (outlet) 61:Bottom 62:Cylinder part 62a: Communication port 65: Axial support part 68: Depression O1: Axis line

Claims

1. a casing having an inlet through which a fluid flows in from the outside and an outlet through which the fluid flows out to the outside; a rotor having a cylindrical valve body with a bottom that forms an internal space through which a fluid flows, the rotor being accommodated in the casing so as to be rotatable around the axis of the valve body; the rotor switches between communication and blocking between at least one of the inlet and the outlet and the internal space through a communication port formed in the valve body in accordance with a rotational position of the valve body; the casing includes an axial support portion that is in sliding contact with a bottom portion of the valve body from an outside of the valve body in the axial direction of the valve body and that rotatably supports the valve body via the bottom portion, The casing comprises: a casing body formed in a cylindrical shape with a bottom having a bottom wall portion and a peripheral wall portion, and in which the inlet and the outlet are formed; an inlet joint connected to an open end surface of the inlet of the casing body, The axial support portion protrudes from the bottom wall portion in the axial direction and is integrally formed with the casing body.

2. 2. The control valve according to claim 1, wherein a recessed portion recessed in the axial direction relative to the axial support portion is formed in a portion of the casing that is positioned radially outward from the axial support portion.

3. 3. The control valve according to claim 2, wherein the recessed portion is defined only by the casing body.

4. 4. The control valve according to claim 1, wherein the axial support portion extends continuously over the entire circumference around the axis.

5. a casing having an inlet through which a fluid flows in from the outside and an outlet through which the fluid flows out to the outside; a rotor having a cylindrical valve body with a bottom that forms an internal space through which a fluid flows, the rotor being accommodated in the casing so as to be rotatable around the axis of the valve body; the rotor switches between communication and blocking between at least one of the inlet and the outlet and the internal space through a communication port formed in the valve body in accordance with a rotational position of the valve body; the casing includes an axial support portion that is in sliding contact with a bottom portion of the valve body from an outside of the valve body in the axial direction of the valve body and that rotatably supports the valve body via the bottom portion, The axial support portion is a control valve provided intermittently around the axis.

6. 6. The control valve according to claim 1, wherein the casing is provided with a radial support portion that enters the internal space through the opening of the valve body and rotatably supports the cylindrical portion of the valve body from the radially inner side.

7. a casing having an inlet through which a fluid flows in from the outside and an outlet through which the fluid flows out to the outside; a rotor having a cylindrical valve body with a bottom that forms an internal space through which a fluid flows, the rotor being accommodated in the casing so as to be rotatable around the axis of the valve body; the rotor switches between communication and blocking between at least one of the inlet and the outlet and the internal space through a communication port formed in the valve body in accordance with a rotational position of the valve body; the casing includes an axial support portion that is in sliding contact with a bottom portion of the valve body from an outside of the valve body in the axial direction of the valve body and that rotatably supports the valve body via the bottom portion, The rotor protrudes from the bottom in the axial direction only toward the side opposite the internal space, and has a shaft portion rotatably supported by the casing.

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