CONTROL VALVE

A control valve includes a casing and a rotor. The casing has an inlet and an outlet. The rotor has a peripheral wall in which communication ports are formed. The peripheral wall of the rotor has a gradually decreasing diameter surface of which an outer diameter gradually decreases from one end side to the other end side in an axial direction and in which the communication port is formed. The rotor accommodating portion of the casing has a rotor guide surface in which an amount of protrusion inward in the radial direction gradually increases from one end side to the other end side in the axial direction, and of which an inner end surface in the radial direction is slidably in contact with the gradually decreasing diameter surface of the peripheral wall. An outlet is disposed in a part of the rotor guide surface so as to face the peripheral wall of the rotor.

TECHNICAL FIELD

The present invention relates to a control valve.

Priority is claimed on Japanese Patent Application No. 2021-201629, filed Dec. 13, 2021, the content of which is incorporated herein by reference.

BACKGROUND ART

Vehicles are equipped with a cooling system that cools a heat generating portion using a cooling liquid that circulates between a heat generating portion (for example, an engine, a motor, or the like) and a heat radiating part (for example, a radiator, a heater core, or the like). In this type of cooling system, a control valve is provided on a flow path that connects a heat generating portion and a heat radiating part to control a flow of the cooling liquid.

As the above-described control valve, for example, Patent Document 1 below discloses a configuration including a casing having an outlet of a cooling liquid and a tubular rotor with a bottom that is rotatably provided within the casing. A communication port which allows communication between an inner space of the rotor and an outlet according to rotation of the rotor is formed in a tubular portion of the rotor.

According to such a configuration, communication and disconnection between the outlet and the communication port can be switched between by rotating the rotor. The cooling liquid that is introduced into the control valve flows into the inner space of the rotor and then flows out of the control valve through the outlet that communicates with the communication port. Thus, the cooling liquid that is introduced into the control valve is distributed to a desired heat radiating part in accordance with the rotation of the rotor.

Further, in this control valve, a seal cylinder of which an end surface is slidably in contact with an outer peripheral surface of the rotor is mounted in the outlet so as to be movable forward and backward. The seal cylinder is biased in a direction of the outer peripheral surface of the rotor by a biasing member such as a coil spring.

In the control valve, with the above-described configuration, even when the tubular portion of the rotor expands and contracts due to heat, communication and disconnection between the outlet and the communication port can be stably performed. That is, when the tubular portion of the rotor expands and contracts due to heat, the seal cylinder is displaced forward and backward according to a change in an outer diameter of the tubular portion, and accordingly, a state of contact between an outer peripheral surface of the tubular portion of the rotor and the seal cylinder is maintained.

CITATION LIST

Patent Document

SUMMARY OF INVENTION

Technical Problem

In the conventional control valve described above, the rotor is rotatably supported by a casing via a dedicated bearing provided between the rotor and the casing. Further, the seal cylinder and the biasing member described above are assembled at a position outside the rotor in a radial direction within the casing. Thus, the conventional control valve described above has a large number of parts and a complicated structure, and there is still room for improvement in reducing a size of the entire device.

An aspect of the present invention has been made in consideration of such circumstances, and an object thereof is to provide a control valve capable of reducing the number of parts, simplifying a structure, and reducing a size of an entire device.

Solution to Problem

In order to solve the above problems, the present invention employs the following aspects.

(1) A control valve according to one aspect of the present invention includes a casing having an inlet through which a fluid is introduced from outside and an outlet through which the fluid flows out to the outside, and a rotor having a peripheral wall in which a communication port passing therethrough in a radial direction is formed, rotatably accommodated inside the casing, and configured to switch between a communication state in which the inlet and the outlet communicate with each other through the communication port and a blocking state in which communication between the inlet and the outlet is blocked in a region of the peripheral wall in which the communication port is not provided, according to a rotational position, wherein the peripheral wall of the rotor has a gradually decreasing diameter surface of which an outer diameter gradually decreases from one end side to the other end side in an axial direction along a rotational axis of the rotor and in which the communication port is formed, a rotor accommodating portion of the casing that accommodates the rotor has a rotor guide surface in which an amount of protrusion inward in the radial direction gradually increases from the one end side to the other end side in the axial direction and an inner end surface in the radial direction is slidably in contact with the gradually decreasing diameter surface of the peripheral wall, and the outlet is disposed in a part of the rotor guide surface to face the gradually decreasing diameter surface of the rotor.

According to the above aspect, the rotor accommodated in the casing is slidably supported by the rotor guide surface on the casing side in the gradually decreasing diameter surface. Since the outlet is disposed in the rotor guide surface so as to face the gradually decreasing diameter surface of the rotor, the outlet is opened and closed by the gradually decreasing diameter surface of the rotor according to a rotational position of the rotor (opened and closed by a region in which the communication port is present and a region in which the communication port is not present in the gradually decreasing diameter surface).

In addition, since both the gradually decreasing diameter surface and the rotor guide surface are inclined or curved radially inward from the same end side to the same other end side in the axial direction, when an outer diameter of the peripheral wall of the rotor expands and contracts due to heat, the rotor is displaced in the axial direction on the rotor guide surface in accordance with an increase or decrease in the outer diameter of the peripheral wall. Therefore, the gradually decreasing diameter surface of the rotor is stably and slidably supported on the rotor guide surface, regardless of the expansion and contraction changes of the peripheral wall due to heat. Therefore, it becomes possible to omit a dedicated bearing for rotatably supporting the rotor on the casing, and it becomes possible to omit a seal cylinder for allowing communication between the outlet and the communication port in the peripheral wall of the rotor and a biasing member for biasing the seal cylinder in a direction of the peripheral wall of the rotor.

(2) In the aspect (1), the gradually decreasing diameter surface may be formed by a tapered surface of which an outer diameter gradually decreases at a constant rate from the one end side to the other end side in the axial direction, and the rotor guide surface may be formed by a tapered surface of which an amount of protrusion inward in the radial direction gradually increases from the one end side to the other end side in the axial direction at the same constant rate as the gradually decreasing diameter surface.

In this case, since the gradually decreasing diameter surface and the rotor guide surface are formed by tapered surfaces inclined at the same angle, even when the peripheral wall of the rotor expands and contracts due to heat and the rotor is displaced in the axial direction, it is possible to bring the gradually decreasing diameter surface into stable contact with the rotor guide surface over a wide area.

(3) In the aspect (1) or (2), in the rotor, an opening portion may be provided on the one end side of the peripheral wall in the axial direction, and the other end side in the axial direction may be closed by a bottom wall, and the opening portion may communicate with the inlet.

In this case, when a fluid is introduced into the casing from the inlet, the fluid is introduced into the peripheral wall through the opening portion of the rotor. At this time, the rotor is pressed to the other end side in the axial direction by a pressure of the fluid, and a component force thereof acts as a pressing force that presses the gradually decreasing diameter surface of the rotor against the rotor guide surface on the casing side. As a result, when the gradually decreasing diameter surface of the rotor is pressed against a peripheral edge portion of the outlet of the rotor guide surface and the communication port of the rotor communicates with the outlet, leakage of the fluid from the peripheral edge portion of the outlet is curbed. Further, when the communication port of the rotor does not communicate with the outlet, leakage of the fluid to the communication port is curbed.

(4) In the aspect (3), the inlet may be formed in a tubular wall that extends into the opening portion in the axial direction of the peripheral wall.

In this case, when the fluid is introduced into the peripheral wall of the rotor from the inlet, a flow of the fluid is less likely to directly hit an end portion of the peripheral wall on one end side in the axial direction or a peripheral portion thereof. Therefore, it is possible to curb pressure loss of the fluid introduced into the peripheral wall of the rotor.

(5) In any one of the aspects (1) to (4), a biasing member that urges the rotor to the other end side in the axial direction may be disposed between the casing and the rotor.

In this case, the component force of the biasing member that urges the rotor to the other end side in the axial direction acts as a force that presses the gradually decreasing diameter surface of the rotor against the rotor guide surface on the casing side. As a result, a peripheral edge portion of the outlet of the rotor guide surface is pressed against the gradually decreasing diameter surface of the rotor, and leakage of the fluid at the peripheral edge portion of the outlet is curbed.

(6) In any one of the aspects (1) to (5), the rotor guide surface may be formed in an annular shape in the rotor accommodating portion to surround a peripheral region of the gradually decreasing diameter surface.

In this case, since a peripheral region of the gradually decreasing diameter surface on the rotor side comes into contact with the annular rotor guide surface, the rotor is maintained in a stable posture during rotation of the rotor.

(7) In any one of the aspects (1) to (5), a plurality of boss portions that protrude toward the gradually decreasing diameter surface of the rotor may be provided on an inner peripheral surface of the rotor accommodating portion, and an end surface of each of the boss portions may serve as the rotor guide surface, and the outlet may be disposed in an end surface of at least one of the boss portions.

In this case, since only the end surface of each of the boss portions comes into contact with the gradually decreasing diameter surface on the rotor side as the rotor guide surface, a contact area between the gradually decreasing diameter surface and the rotor guide surface becomes small. Therefore, sliding resistance during the rotation of the rotor is reduced, and the rotation of the rotor becomes smoother.

(8) In the aspect (7), the plurality of boss portions may be provided on the inner peripheral surface of the rotor accommodating portion at equal intervals in a circumferential direction.

In this case, since the plurality of rotor guide surfaces are evenly in contact with the peripheral wall (the gradually decreasing diameter surface) of the rotor in the circumferential direction, the peripheral wall of the rotor is stably supported by the plurality of rotor guide surfaces.

(8) In the aspect (5), the biasing member may be a coil spring, and a spring receiving member having a flat contact surface with the rotor may be disposed at an end portion of the coil spring on the rotor side.

In this case, the biasing member is constituted by a coil spring that is highly durable and has a simple structure. Since a contact surface with the rotor is in contact with the rotor via the flat spring receiving member, the coil spring can prevent an end portion of the coil spring from interfering with the rotation of the rotor when the rotor rotates, and can also prevent the end portion of the coil spring from damaging the end surface of the rotor. As a result, it is possible to obtain smooth rotation of the rotor, and it is also possible to prevent damage to the rotor.

Advantageous Effects of Invention

In the aspect of the present invention, the gradually decreasing diameter surface of the peripheral wall of the rotor and the rotor guide surface on the casing side are both inclined or curved radially inward from the same end side to the same other end side in the axial direction, and the outlet is disposed in the rotor guide surface on the casing side so as to face the gradually decreasing diameter surface on the rotor side. Therefore, the peripheral wall of the rotor can always be stably and slidably supported by the rotor guide surface on the casing side. Furthermore, since a peripheral edge portion of the rotor guide surface in which the outlet is disposed is slidably in contact with the gradually decreasing diameter surface on the rotor side, it is possible to omit a seal cylinder for allowing communication between the outlet and the communication port in the peripheral wall of the rotor and a biasing member for biasing the seal cylinder toward the peripheral wall of the rotor.

Therefore, when the aspect of the present invention is adopted, the number of parts such as bearings, seal cylinders, and biasing members can be reduced and the structure can be simplified, thereby making it possible to reduce a size of the entire device.

DESCRIPTION OF EMBODIMENTS

Next, embodiments of the present invention will be described on the basis of the drawings. In each of the embodiments described below, corresponding components may be designated by the same reference numerals and description thereof may be omitted.

In the following description, for example, expressions indicating a relative or absolute arrangement such as “parallel,” “orthogonal,” “centered,” and “coaxial” do not only refer strictly to such arrangements, and also indicate states of being relatively displaced by an angle or distance that allows the same tolerances and functions to be obtained.

FIG.1is a block diagram of the cooling system1.

As shown inFIG.1, a cooling system1is mounted in, for example, a vehicle. In this embodiment, the vehicle is not limited to one having an engine (an internal combustion engine) as a vehicle drive source, and may be an electric motor vehicle. The electric motor vehicle includes an electric vehicle, a hybrid vehicle, a plug-in hybrid vehicle, a fuel cell vehicle, and the like.

The cooling system1includes a heat generating portion2, a heat radiating part3, a water pump4(W/P), and a control valve5(EWV). In the cooling system1, the water pump4and the control valve5operate to circulate a cooling liquid between the heat generating portion2and the heat radiating part3.

The heat generating portion2is a component to be cooled by the cooling liquid (a target for heat absorption by the cooling liquid), and is a drive source of a vehicle or other heat generating components. In the case of an electric motor vehicle, the heat generating portion2includes, for example, a drive motor, a battery, a power converter, and the like.

The heat radiating part3is a component to which heat is radiated from the cooling liquid. In this embodiment, the heat radiating part3includes a radiator8(RAD) and a heater core9(HTR). As the heat radiating part3, any member can be selected as long as a temperature during a normal operation is lower than a temperature of the cooling liquid after the cooling liquid passes through the heat generating portion2. As such a component, the heat radiating part3may be, for example, an EGR cooler that exchanges heat between EGR gas and the cooling liquid, a heat exchanger that exchanges heat between lubricating oil and the cooling liquid, or the like.

The water pump4, the heat generating portion2, and the control valve5are connected in order from upstream to downstream on a main flow path10. In the main flow path10, the cooling liquid passes through the heat generating portion2and the control valve5in order by an operation of the water pump4.

A radiator flow path11and an air conditioning flow path12are connected to the main flow path10.

The radiator8is provided in the radiator flow path11. The radiator flow path11is connected to the control valve5at a portion located upstream of the radiator8. The radiator flow path11is connected to the heat generating portion2at a portion located downstream of the radiator8. In the radiator flow path11, heat exchange between the cooling liquid and external air is performed in the radiator8.

The heater core9is provided in the air conditioning flow path12. The air conditioning flow path12is connected to the control valve5at a portion located upstream of the heater core9. The air conditioning flow path12is connected to the heat generating portion2at a portion located downstream of the heater core9. The heater core9is provided, for example, in a duct (not shown) of an air conditioner. In the air conditioning flow path12, heat exchange is performed in the heater core9between the cooling liquid and conditioned air flowing through the duct.

In the cooling system1, the cooling liquid introduced into the control valve5by the operation of the water pump4is selectively supplied to one of the heat radiating parts3by an operation of the control valve5. The cooling liquid supplied to the heat radiating part3exchanges heat with the heat radiating part3during a process in which the cooling liquid passes through the heat radiating part3. As a result, the cooling liquid is cooled by the heat radiating part3. The cooling liquid that has passed through the heat radiating part3is supplied to the heat generating portion2and then exchanges heat with the heat generating portion2during a process in which the cooling liquid passes through the heat generating portion2. Thus, the heat generating portion2is cooled by the cooling liquid. As described above, in the cooling system1, during a process in which the cooling liquid is circulated between the heat generating portion2and the heat radiating part3, the heat generating portion2is cooled by the cooling liquid, while the cooling liquid is cooled by the heat radiating part3. Thus, in the cooling system1, the heat generating portion2can be controlled to a desired temperature.

FIG.2is a perspective view of the control valve5, andFIG.3is an exploded perspective view of the control valve5.FIG.4is a cross-sectional view of the control valve5taken along line IV-IV inFIG.2.

As shown inFIGS.2to4, the control valve5includes a casing21, a drive unit22, and a rotor23.

The casing21includes a casing main body31and an introduction joint32. The casing main body31is formed into a tubular shape with a bottom having a bottom wall portion31aand a peripheral wall portion31b. In the following description, a direction along an axis O1of the casing main body31is simply referred to as an axial direction. When seen in the axial direction, a direction intersecting the axis O1is referred to as a radial direction, and a direction around the axis O1is referred to as a circumferential direction.

Further, in the axial direction, the side (the opening side) of the casing main body31opposite to the bottom wall portion31ais referred to as one end side, and the bottom wall portion31aside thereof is referred to as the other end side.

The bottom wall portion31aof the casing main body31protrudes outward in the radial direction in a rectangular shape so that the other end side in the axial direction substantially matches an exterior of the drive unit22which will be described below. The drive unit22is superimposed on this portion, and the drive unit22is fixed with screws or the like. Furthermore, a through hole31cthat passes through the bottom wall portion31ain the axial direction is formed in a portion of the bottom wall portion31alocated on the axis O1. A shaft portion23aof the rotor23which will be described below is rotatably inserted into the through hole31c.

Two outflow ports33A and33B that protrude outward in the radial direction are formed in the peripheral wall portion31bof the casing main body31. The two outflow ports33A and33B extend in opposite directions around the axis O1. An outlet34that communicates with the inside of the casing main body31is formed in each of the outflow ports33A and33B. One outflow port33A is connected to the upstream side of one of the radiator flow path11and the air conditioning flow path12shown inFIG.1, and the other outflow port33B is connected to the upstream side of the other of the radiator flow path11and the air conditioning flow path12.

In this embodiment, the two outflow ports33A and33B are provided in the peripheral wall portion31bof the casing main body31, but the number of outflow ports may be one or three or more according to a flow path configuration of the cooling system1. In the case of three or more outflow ports, it is desirable that the outflow ports are disposed evenly (at equal intervals) on the circumference of the peripheral wall portion31b.

As shown inFIG.4, in the casing main body31, an inner peripheral portion of the peripheral wall portion31bcloser to the bottom wall portion31aserves as a rotor accommodating portion35. A peripheral wall23bof the rotor23which will be described below is rotatably accommodated in the rotor accommodating portion35.

The inner peripheral surface35aof the rotor accommodating portion35is formed in a tapered shape of which an inner diameter gradually decreases at a constant rate from one end side to the other end side in the axial direction. In other words, in this tapered shape, an amount of protrusion inward in the radial direction gradually increases from one end side to the other end side in the axial direction. Each of the outlets34of the two outflow ports33A and33B described above opens to the inner peripheral surface35aof the rotor accommodating portion35. Further, the peripheral wall23bof the rotor23which will be described below is rotatably supported on the tapered inner peripheral surface35aof the rotor accommodating portion35. In this embodiment, the inner peripheral surface35aof the rotor accommodating portion35constitutes a rotor guide surface.

In addition, a region in an inner peripheral portion of the peripheral wall portion31bthat is closer to the one end side in the axial direction than the rotor accommodating portion35is formed to have the same inner diameter as a maximum inner diameter of the rotor accommodating portion35(the inner peripheral surface35a). This portion serves as a spring accommodating portion36in which a coil spring50which will be described below is accommodated. Further, one end side of the spring accommodating portion36in the axial direction opens outward of the casing main body31, and a cooling liquid (a fluid) introduced from the introduction joint32which will be described below flows therethrough.

The introduction joint32is mounted on an end surface of the casing main body31on one end side in the axial direction. The introduction joint32includes a joint tubular portion32aand a flange portion32b.

An inlet37through which the cooling liquid (the fluid) is introduced into the casing21is formed in the joint tubular portion32a. The inlet37is connected to the downstream side of the heat generating portion2of the main flow path10shown inFIG.1. The flange portion32bis formed to protrude outward in the radial direction at an end portion of the joint tubular portion32ain the axial direction. The flange portion32bis superimposed on the end surface of the casing main body31and is fixed to the end portion of the casing main body31by screws or the like with a packing52sandwiched therebetween. An inner diameter of the flange portion32bis set smaller than an inner diameter of the spring accommodating portion36of the casing main body31.

Therefore, an inner peripheral edge portion of the flange portion32bfaces inside the end portion of the spring accommodating portion36of the casing main body31.

The introduction joint32(the flange portion32b) may be mounted on an opening end surface of the inlet37by welding (for example, vibration welding, or the like).

The drive unit22has a built-in motor, deceleration mechanism, control board, and the like (not shown). An output shaft22aprotrudes from a surface of the drive unit22on the side that is mounted on the casing21. The output shaft22ais engaged with the shaft portion23aof the rotor23that passes through the bottom wall portion31aof the casing main body31to be able to transmit rotation. The shaft portion23aof the rotor23can be relatively displaced in the axial direction through spline engagement with the output shaft22a.

The rotor23is rotatably accommodated inside the casing21. The rotor23accommodated in the casing21is rotatable around the axis O1. The rotor23includes the shaft portion23a, the peripheral wall23b, and a bottom wall23c.

The shaft portion23ais inserted into the through hole31cof the bottom wall portion31aof the casing main body31, and the peripheral wall23bis accommodated in the rotor accommodating portion35of the casing main body31. The bottom wall23ccloses off the other end side of the peripheral wall23bin the axial direction. The shaft portion23aprotrudes coaxially with the peripheral wall23bat a center of the other end side of the bottom wall23cin the axial direction. An opening portion23dis provided at one end side of the peripheral wall23bin the axial direction.

The rotor23accommodated in the casing21is disposed coaxially with the axis O1of the casing21. Therefore, a rotational axis of the rotor23coincides with the axis O1of the casing21. The shaft portion23apasses through the bottom wall portion31athrough the through hole31c. An outer spline23sthat is spline-engaged with the output shaft22aof the drive unit22is formed on the other end side of the shaft portion23ain the axial direction. The shaft portion23ais spline-engaged with the output shaft22aof the drive unit22outside the bottom wall portion31a.

The peripheral wall23bof the rotor23has a tapered shape (a truncated conical shape) of which an outer diameter gradually decreases at a constant rate from one end side to the other end side in the axial direction. In this embodiment, an outer peripheral surface of the peripheral wall23bconstitutes a gradually decreasing diameter surface38. The gradually decreasing diameter surface38is slidably in contact with the tapered inner peripheral surface35aof the rotor accommodating portion35in a state in which the peripheral wall23bis accommodated in the rotor accommodating portion35of the casing main body31. The rotor23is rotatably supported by the inner peripheral surface35aof the rotor accommodating portion35.

In this embodiment, a diameter reduction ratio of the outer diameter of the gradually decreasing diameter surface38(a diameter reduction ratio from one end side to the other end side in the axial direction) is set to be the same as a diameter reduction ratio of the inner peripheral surface35aon the casing21side. Therefore, when the peripheral wall23bof the rotor23expands and contracts due to heat, the peripheral wall23bis smoothly guided by the inner peripheral surface35aaccording to a change in the outer diameter of the peripheral wall23b(the gradually decreasing diameter surface38) and is displaced in the axial direction.

The gradually decreasing diameter surface38and the inner peripheral surface35aon the casing21side do not necessarily have to be formed in a tapered shape, and may have a shape which gently curves and of which a diameter gradually decreases from one end side to the other end side in the axial direction.

Furthermore, two communication ports39A and39B which pass through the peripheral wall23bin the radial direction are formed in the peripheral wall23bof the rotor23. In a state in which the rotor23is accommodated in the rotor accommodating portion35of the casing21, the two communication ports39A and39B are formed at positions that are approximately at the same height (approximately the same axial region) as the two outlets34facing the inner peripheral surface35aof the rotor accommodating portion35. Each of the communication ports39A and39B communicates with one of the outlets34when the rotor23is at a predetermined rotational position.

The communication ports39A and39B on the rotor23side and the outlets34on the casing21side are set in positions, sizes, and shapes such that they can communicate reliably at a predetermined rotational position even when the peripheral wall23bof the rotor23is displaced in the axial direction by expansion and contraction due to heat.

In this embodiment, the two communication ports39A and39B are formed in the peripheral wall23bof the rotor23, but the number of communication ports formed in the peripheral wall23bmay be one or three or more.

Further, the peripheral wall23bof the rotor23of this embodiment is formed to have a constant thickness throughout an entire region in the circumferential direction and the axial direction. Therefore, when the rotor23is molded, a dividing plane of a mold can be disposed at an end portion of the peripheral wall on the other end side in the axial direction. In this case, the dividing plane is a plane perpendicular to the axial direction, and two molds with the dividing planes butted against each other can be cut out in the axial direction. In the rotor23formed by such a mold, no parting line is formed on the outer peripheral surface of the peripheral wall23b. Therefore, it is possible to prevent the parting line formed on the outer peripheral surface of the rotor23from causing leakage of the cooling liquid at a contact surface between the outer peripheral surface of the rotor23and the inner peripheral surface35aon the casing21side.

The opening portion23dof the peripheral wall23bon one end side in the axial direction communicates with the inlet37of the introduction joint32through the spring accommodating portion36of the casing main body31. Therefore, the inlet37of the casing21communicates with an inner space K1of the rotor23surrounded by the peripheral wall23band the bottom wall23c. The cooling liquid (the fluid) introduced into the inner space K1of the rotor23from the inlet37flows out to the outlet34of the outflow ports33A and33B through the communication port39A or39B according to a rotational position of the rotor23.

<Seal Structure of Rotor23>

As shown inFIG.4, a seal accommodating portion66is formed in the bottom wall portion31aof the casing21at a position facing an outer surface (a surface on the other end side in the axial direction) of the bottom wall23cof the rotor23. The seal accommodating portion66is a recessed portion that opens to one end side in the axial direction and communicates with the through hole31cat the center of the bottom portion. An annular seal member67is fitted into the seal accommodating portion66. The seal member67is an annular member mainly made of an elastic member that is U-shaped in cross-sectional view. The seal member67seals between an outer peripheral surface of the shaft portion23aand an inner peripheral surface of the seal accommodating portion66within the seal accommodating portion66.

An annular wall68and an annular recess69are formed in the bottom wall portion31aat a position outward of the seal accommodating portion66in the radial direction. The annular wall68is disposed inside the annular recess69in the radial direction and separates the seal accommodating portion66and the recess69from each other. A protruding end of the annular wall68is disposed close to the outer surface of the bottom wall23cof the rotor. The recess69forms a stagnation region for the cooling liquid to trap contaminants and the like contained in the cooling liquid before the cooling liquid enters the seal accommodating portion66. A surface of an inner surface of the recess69that faces inward in the radial direction is constituted by an inner peripheral surface of the peripheral wall portion31b. On the other hand, a surface of the inner surface of the recess69that faces outward in the radial direction is formed by an outer peripheral surface of the annular wall68.

<Biasing Structure of Rotor23>

As shown inFIG.4, the coil spring50made of a thin plate material is accommodated in the spring accommodating portion36of the casing main body31together with a spring receiving member51in the form of an annular sheet. The coil spring50is formed to have approximately the same outer diameter as an end surface of the peripheral wall23bof the rotor23on one end side in the axial direction. The spring receiving member51is disposed at an end portion of the coil spring50on the other end side in the axial direction. An end surface of the spring receiving member51on the rotor23side is formed to be flat. When the coil spring50and the spring receiving member51are accommodated in the spring accommodating portion36, the spring receiving member51comes into contact with the end surface of the peripheral wall23bof the rotor23. At this time, a lower end surface of the coil spring50comes into contact with an inner peripheral edge portion of the flange portion32bof the introduction joint32.

The coil spring50is a compression spring, and urges the rotor23to the other end side in the axial direction in a state in which it is accommodated in the spring accommodating portion36. A biasing force of the coil spring50presses the gradually decreasing diameter surface38of the peripheral wall23bof the rotor23against the inner peripheral surface35a(the rotor guide surface) on the casing21side with a weak force.

Further, a flow of the cooling liquid introduced into the inner space K1of the rotor23from the inlet37of the casing21hits the peripheral wall23band the bottom wall23cof the rotor23, thereby pressing the rotor23to the other end side in the axial direction. Therefore, the flow of the cooling liquid introduced into the inner space K1of the rotor23presses the gradually decreasing diameter surface38of the peripheral wall23bof the rotor23against the inner peripheral surface35a(the rotor guide surface) on the casing21side with a weak force.

<Method of Operating Control Valve5>

Next, a method of operating the control valve5described above will be described. In the following description, it is assumed that the outlet34of one outflow port33A of the casing21is connected to the radiator flow path11, and the outlet34of the other outflow port33B is connected to the air conditioning flow path12.

As shown inFIG.1, in the main flow path10, the cooling liquid sent out by the water pump4exchanges heat in the heat generating portion2, and then flows toward the control valve5. The cooling liquid that has passed through the heat generating portion2in the main flow path10is introduced into the inner space K1through the inlet37of the introduction joint32shown inFIG.4. The cooling liquid that has been introduced into the inner space K1fills the entire region inside the casing main body31through the communication ports39A and39B, a gap between the rotor23and the casing21, and the like.

When the communication ports39A and39B of the rotor23are not superimposed on the outlet34of any of the outflow ports33A and33B when seen in the radial direction, communication between the inner space K1of the rotor23and the outlets34of the outflow ports33A and33B is blocked (a blocked state). In the blocked state, the introduction of the cooling liquid in the inner space K1into the outlet34through the communication ports39A and39B is restricted.

When it is desired to supply the cooling liquid to the radiator8, for example, the communication port39A and the outlet34of one outflow port33A communicate with each other. Specifically, the drive unit22is driven to rotate the rotor23around the axis O1. At this time, the rotor23rotates around the axis O1while the gradually decreasing diameter surface38of the peripheral wall23bslides on the inner peripheral surface35a(the rotor guide surface) of the casing main body31. Then, the communication port39A is superimposed on the outlet34of one outflow port33A when seen in the radial direction, and thus the communication port39A and the outlet34of one outflow port33A communicate with each other (a communicating state). In the communicating state, the cooling liquid in the inner space K1flows out to the outlet34through the communication port39A. The cooling liquid flowing out to the outlet34is distributed to the radiator flow path11as shown inFIG.1. The cooling liquid distributed to the radiator flow path11passes through the radiator8, is then returned to the main flow path10and is introduced into the control valve5again.

On the other hand, when it is desired to supply the cooling liquid to the heater core9, the communication port39B communicates with the outlet34of the other outflow port33B, for example, by a method similar to the method described above. Thus, the cooling liquid flowing out of the inner space K1flows into the outlet34of the other outflow port33B and is distributed to the air conditioning flow path12.

In this way, in the control valve5of this embodiment, communication and disconnection between the inner space K1and each of the outlets34through the communication ports39A and39B are switched according to the rotational position of the rotor23. Thus, the cooling liquid can be distributed to a desired flow path.

Effects of First Embodiment

As described above, in the control valve5of this embodiment, the gradually decreasing diameter surface38of which an outer diameter gradually decreases from one end side to the other end side in the axial direction is provided on the peripheral wall23bof the rotor23, and the inner peripheral surface35a(the rotor guide surface) of which the amount of protrusion inward in the radial direction gradually increases from one end side to the other end side in the axial direction is provided in the rotor accommodating portion35on the casing21side. The inner peripheral surface35a(the rotor guide surface) of the rotor accommodating portion35is slidably in contact with the gradually decreasing diameter surface38on the rotor23side, and the outlets34are formed so as to face the gradually decreasing diameter surface38. With this configuration, when the outer diameter of the peripheral wall23bof the rotor23expands or contracts due to heat, the rotor23is displaced in the axial direction on the inner peripheral surface35a(the rotor guide surface) of the rotor accommodating portion35according to an increase or decrease in the outer diameter of the peripheral wall23b. Therefore, the gradually decreasing diameter surface38of the rotor23is stably and slidably supported on the inner peripheral surface35aof the rotor accommodating portion35, regardless of the expansion and contraction changes of the peripheral wall23bdue to heat.

Furthermore, in this configuration, since the peripheral edge portion of the inner peripheral surface35aof the rotor accommodating portion35at the portion at which the outlets34are disposed is slidably in contact with the gradually decreasing diameter surface38on the rotor23side, the seal cylinder for allowing communication between the outlets34and the communication ports39A and39B of the peripheral wall23bof the rotor23and the biasing member for biasing the seal cylinder in the direction of the peripheral wall of the rotor23can be omitted.

Therefore, when the control valve5of this embodiment is adopted, the number of components such as bearings, the seal cylinder, and the biasing member can be reduced and the structure can be simplified, thereby making it possible to reduce a size of the entire device.

Further, in the control valve5of this embodiment, the gradually decreasing diameter surface38on the rotor23side and the inner peripheral surface35aof the rotor accommodating portion35on the casing21side are both tapered surfaces of which inclinations change at a constant rate from one end side to the other end side in the axial direction. Therefore, even when the peripheral wall23bof the rotor23expands and contracts due to heat and thus the rotor23is displaced in the axial direction, the gradually decreasing diameter surface38and the inner peripheral surface35aof the rotor accommodating portion35can be brought into stable contact over a wide area.

Therefore, when this configuration is adopted, it is possible to stabilize the operation of the rotor23, and it is also possible to prevent unnecessary internal leakage of the cooling liquid.

Further, in the control valve5of this embodiment, the opening portion23dis provided at one end side of the peripheral wall23bof the rotor23, the other end side of the peripheral wall23bof the rotor23is closed by the bottom wall23c, the opening portion23dcommunicates with the inlet37of the casing21, and the outlet34is formed in the inner peripheral surface of the rotor accommodating portion35on the casing21side. Therefore, when the cooling liquid is introduced into the casing21from the inlet37, the cooling liquid is introduced into the peripheral wall23bthrough the opening portion23dof the rotor23. At this time, the rotor23is pressed to the other end side in the axial direction by pressure of the cooling liquid, and a component force thereof acts as a pressing force that presses the gradually decreasing diameter surface38of the rotor23against the inner peripheral surface35aon the casing21side. As a result, when the gradually decreasing diameter surface38of the rotor23is pressed against the peripheral edge portion of the outlet34of the inner peripheral surface35aon the casing21side, and the communication ports39A and39B of the rotor23communicate with the outlet34, leakage of the cooling liquid from the peripheral edge portion of the outlet34is curbed. Furthermore, when the communication ports39A and39B of the rotor23do not communicate with the outlet34, leakage of the cooling liquid to the outlet34is curbed.

Therefore, when this configuration is adopted, the gradually decreasing diameter surface38on the rotor23side is always in stable contact with the inner peripheral surface35aon the casing21side, and unnecessary internal leakage of the cooling liquid can be curbed.

Further, in the control valve5of this embodiment, the coil spring50(the biasing member) that urges the rotor23to the other end side in the axial direction is provided between the casing21and the rotor23. Therefore, the component force of the coil spring50that urges the rotor23to the other end side in the axial direction acts as a force that presses the gradually decreasing diameter surface38of the rotor23against the inner peripheral surface35aon the casing21side.

Therefore, when this configuration is adopted, the gradually decreasing diameter surface38on the rotor23side is always brought into stable contact with the inner peripheral surface35aon the casing21side, thereby making it possible to further curb unnecessary internal leakage of the cooling liquid.

Further, in the control valve5of this embodiment, the inner peripheral surface35aof the rotor accommodating portion35is formed in the rotor accommodating portion35in an annular shape so as to surround a peripheral region of the gradually decreasing diameter surface38of the rotor23. Therefore, the rotor23can be maintained in a stable posture during the rotation of the rotor23.

Therefore, when this configuration is adopted, the operation of the rotor23can be made more stable.

Furthermore, in the control valve5of this embodiment, the spring receiving member51having a flat contact surface with the rotor23is mounted on the end surface of the coil spring50(the biasing member) on the rotor23side that urges the rotor23to the other end side in the axial direction. In this case, since, while the coil spring50that is highly durable and has a simple structure is adopted as the biasing member, the biasing force of the coil spring50acts on the rotor23through the spring receiving member51, it is possible to prevent the end portion of the coil spring50from interfering with the rotation of the rotor23when the rotor23rotates, and it is also possible to prevent the end portion of the coil spring from damaging the end surface of the rotor23.

Therefore, when this configuration is adopted, smooth rotation of the rotor23can be obtained, and damage to the rotor23can also be prevented.

FIG.5is a cross-sectional view of the control valve105of this embodiment which corresponds toFIG.4of the first embodiment.

The basic configuration of the control valve105of this embodiment is the same as that of the above embodiment, but a structure of a part of the introduction joint32is different from the above embodiment. That is, a tubular wall32ethat extends into the opening portion23dof the peripheral wall23bof the rotor23in the axial direction within the casing main body31is provided on the introduction joint32. The inlet37of the casing21is formed across the joint tubular portion32aof the introduction joint32and the tubular wall32e.

Effects of Second Embodiment

Since the control valve105of this embodiment has the same basic configuration as the above embodiment, it can obtain the same basic effects as the above embodiment.

Further, in the control valve105of this embodiment, the tubular wall32ethat extends into the opening portion23dof the peripheral wall23bof the rotor23is provided on the introduction joint32, and the inlet37is formed in the tubular wall32eof the introduction joint32. Therefore, when the cooling liquid (the fluid) is introduced into the peripheral wall23bof the rotor23from the inlet37, a flow of the fluid is less likely to directly hit the end portion of the peripheral wall23bon the one end side in the axial direction or a peripheral portion thereof (a wall of the spring accommodating portion36or the coil spring50). Therefore, when the configuration of this embodiment is adopted, pressure loss of the cooling liquid introduced into the peripheral wall23bof the rotor23can be curbed.

FIG.6is a cross-sectional view of a control valve205of this embodiment which corresponds to the cross section taken along line VI-VI of the first embodiment.

The rotor accommodating portion35of the casing21of the first embodiment has the inner peripheral surface35aformed in a tapered shape such that the inner diameter gradually decreases from one end side to the other end side in the axial direction. In contrast, the inner peripheral surface35aof the rotor accommodating portion35of this embodiment is formed to have a constant inner diameter or to have an inner diameter that gradually decreases from one end side to the other end side in the axial direction. A boss portion55is formed in a portion of the inner peripheral surface35aof the rotor accommodating portion35in which the outlet34of each of the outflow ports33A and33B opens so as to surround each of the outlets34. Each of the boss portions55protrudes inward toward the gradually decreasing diameter surface38of the rotor23in the radial direction.

An end surface55eof each of the boss portions55on the protrusion side is slidably in contact with the gradually decreasing diameter surface38of the rotor23. The end surface55eof each of the boss portions55is formed to have a complementary shape to a part of the gradually decreasing diameter surface38. Specifically, the end surface55eof the boss portion55has an arc-shaped cross section perpendicular to the axis O1, and an inner diameter of the arc gradually decreases from one end side to the other end side in the axial direction. In other words, an amount of protrusion of the end surface55eof the boss portion55inward in the radial direction gradually increases from one end side to the other end side in the axial direction.

In this embodiment, the end surfaces55eof the plurality of boss portions55constitute a rotor guide surface on the casing21side.

Further, in this embodiment, although a boss portion55is formed at a portion of the inner peripheral surface35aof the rotor accommodating portion35in which the outlets34of the two outflow ports33A and33B open, when there are three or more outflow ports, the number of boss portions55may be increased in accordance with the number of outflow ports (outlets). In this case, it is desirable that the boss portions55be disposed evenly in the circumferential direction of the inner peripheral surface35a. Furthermore, the number of boss portions55may be greater than the number of outflow ports (outlets). In this case, some of the boss portions55are not formed with the outflow ports. For example, when there is one outflow port (outlet), one or more boss portions55without the outflow port are provided, and all the boss portions are disposed evenly in the circumferential direction of the inner peripheral surface35a. Thus, the support of the rotor23by the end surface55e(the rotor guide surface) of the boss portion55can be maintained in a good balance.

Effects of the Third Embodiment

Since the control valve205of this embodiment has a basic configuration that is almost the same as that of the first embodiment, it can obtain the same basic effects as the first embodiment.

Further, in the control valve205of this embodiment, only the end surface55eof each of the boss portions55formed on the inner peripheral surface35aof the rotor accommodating portion35comes into contact with the gradually decreasing diameter surface38on the rotor23side as the rotor guide surface. Therefore, a contact area between the gradually decreasing diameter surface38and the rotor guide surface is smaller than that in the first and second embodiments.

Therefore, when the control valve205of this embodiment is employed, sliding resistance during the rotation of the rotor23can be reduced, and the rotation of the rotor23can be made smoother.

In the first, second, and third embodiments described above, although the configuration in which the inlet37faces in the axial direction, and the outlet34faces in the radial direction has been described, the present invention is not limited to this configuration. For example, a configuration in which the outlet faces in the axial direction and the inlet faces in the radial direction, or a configuration in which both the inlet and the outlet face in the radial direction may be used. In this case, the outlet may communicate with the inner space within the rotor, and the inlet may be opened and closed by a communication port in the peripheral wall (the gradually decreasing diameter surface) of the rotor.

FIG.7is a cross-sectional view of a control valve305of this embodiment which corresponds toFIG.4of the first embodiment.

The control valve305of this embodiment is not provided with the biasing member such as a coil spring for biasing a rotor323to the other end side in the axial direction. The rotor323includes the shaft portion23a, the peripheral wall23b, and the bottom wall23c, as in the above embodiment. However, the outer peripheral surface of the peripheral wall23bdoes not have a tapered shape over the entire region in the axial direction, but a straight portion23ehaving a constant outer diameter is provided at one end side in the axial direction.

Further, an annular recess60which opens to the inner side in the radial direction and the one end side in the axial direction is formed in the casing main body31at a position adjacent to one end side of the rotor accommodating portion35in the axial direction. Further, an annular groove61that opens to the other end side in the axial direction is formed in the end surface of the flange portion32bof the introduction joint32that faces the inside of the casing21. A peripheral surface of the recess60of the casing main body31that faces inward in the radial direction is continuous with an outer peripheral surface of the annular groove61of the introduction joint32. The recess60and the annular groove61form an annular end receiving space K2in which a part of the inner peripheral wall and the bottom wall (the wall located on the other end side in the axial direction) is missing. The straight portion23eat the end portion of the peripheral wall23bof the rotor23is accommodated in the end receiving space K2so as to be movable back and forth in the axial direction. A gap d is secured between an end portion23fof the straight portion23eaccommodated in the end receiving space K2and a bottom surface61eof the annular groove61. This gap d is a gap for allowing the displacement of the peripheral wall23b(the straight portion23e) to one end side in the axial direction when the rotor323is displaced to one end side in the axial direction due to thermal expansion of the peripheral wall23bof the rotor323.

Although the control valve305of this embodiment does not include a biasing member for biasing the rotor323to the other end side in the axial direction, the flow of cooling liquid (the fluid) introduced from the inlet37presses the rotor323to the other end side in the axial direction. As a result, the gradually decreasing diameter surface38of the rotor323is pressed against the tapered inner peripheral surface35aon the casing21side. Therefore, even when the rotor323expands and contracts due to heat, it is slidably and stably supported by the inner peripheral surface35aon the casing21side.

Effects of the Fourth Embodiment

Since the control valve305of this embodiment has a basic configuration that is almost the same as that of the first embodiment, it can obtain the same basic effects as the first embodiment.

However, since the control valve305of this embodiment is not provided with an biasing member for biasing the rotor323to the other end side in the axial direction, the number of parts can be further reduced, and an axial length of the control valve305can be shortened.

Further, in the control valve305of this embodiment, the bottom surface61eof the annular groove61faces the end portion23fof the peripheral wall23b(the straight portion23e) of the rotor323with a small gap d therebetween. Therefore, the bottom surface61eof the annular groove61can curb excessive displacement of the rotor323in the axial direction and unnecessary rattling in a state in which the rotor323is not operated.

OTHER EMBODIMENTS

Although preferred embodiments of the present invention have been described above, the present invention is not limited to the embodiments. Additions, omissions, substitutions, and other changes to the configuration are possible without departing from the gist of the present invention. The present invention is not limited by the above description, but is limited only by the scope of the claims appended hereto.

For example, in the embodiment described above, the configuration in which the control valve5is mounted in the cooling system1of the vehicle has been described, but the control valve5is not limited to this configuration and may be mounted in other systems.

In the embodiment described above, the configuration in which the cooling liquid introduced into the control valve5is distributed to the radiator flow path11and the air conditioning flow path12has been described, but the present invention is not limited to this configuration. The control valve5may have any structure as long as it distributes the cooling liquid introduced into the control valve5into a plurality of flow paths.

In the first and second embodiments described above, the coil spring50made of a plate-shaped material is used as the biasing member that urges the rotor23to the other end side in the axial direction, but the present invention is not limited to this configuration. As the biasing member, various other members such as a disc spring or a rubber-like elastic member can be used.

REFERENCE SIGNS LIST