Patent ID: 12196327

DETAILED DESCRIPTION

Previously, there is proposed a valve device, which is used in a fluid circulation system that circulates fluid. The valve device is used to change a flow path of the fluid or control a flow rate of the fluid.

One such a valve device includes: a flow hole forming portion (first valve), which is fixed in an inside of a housing shaped in a tubular form; a rotor (second valve), which is rotatably installed in the housing; a drive device, which is configured to rotate the rotor; and a shaft and a coupling member, which couple between the rotor and the drive device. The flow hole forming portion has: two flow holes, which are configured to conduct the fluid therethrough; and a partition which partitions between the two flow holes. The rotor has: a single passage opening, which is configured to conduct the fluid; and a closing portion, which slidably contacts the flow hole forming portion.

When a torque, which is generated by the drive device, is transmitted to the rotor through the shaft and the coupling member, the rotor is rotated about a rotational axis of the shaft. Therefore, one of the two flow holes of the flow hole forming portion is communicated with the passage opening of the rotor, and the other one of the two flow holes is closed by the closing portion of the rotor. Thus, the fluid, which flows in the inside of the housing, flows through the one of the two flow holes of the flow hole forming portion while the flow of the fluid into the other one of the two flow holes is blocked.

In the valve device described above, a small gap for assembly is provided at each of: a meshing part between gears of the gear mechanism in the drive device; an engaging part between an output gear of the drive device and the shaft; an engaging part between the shaft and the coupling member; and an engaging part between the coupling member and the rotor. Therefore, in a case of rotating the rotor in a forward rotation direction and a reverse rotation direction by transmitting the torque from the drive device to the rotor, a rotation angle of the rotor may possibly vary relative to a rotation angle of the drive device. Therefore, at the time of flowing the fluid through one of the flow holes of the flow hole forming portion by rotating the rotor to a predetermined position while blocking the other one of the flow holes, the fluid may unintentionally leak into the other one of the flow holes due to the variation in the stop position of the rotor.

With respect to this disadvantage, it is conceivable to increase a width of the partition of the flow hole forming portion to limit the leakage of the fluid into the other flow hole even in the case where the variation in the stop position of the rotor occurs. However, in this configuration, a passage cross-sectional area of the respective flow holes of the flow hole forming portion becomes small, and thereby a pressure loss of the fluid passing through the opened flow hole among the flow holes is disadvantageously increased.

According to one aspect of the present disclosure, a valve device includes a housing, a flow hole forming portion, a rotor and a drive device. The housing has a passage configured to conduct fluid. The flow hole forming portion is fixed at the passage of the housing and includes: a plurality of flow holes, each of which is configured to conduct the fluid; and at least one partition (or a plurality of partitions) which is placed between corresponding adjacent two of the plurality of flow holes. The rotor is placed in the passage of the housing and is configured to rotate about a rotational axis which is predetermined. The rotor includes: a passage opening which is configured to communicate with a corresponding predetermined flow hole among the plurality of flow holes of the flow hole forming portion according to a rotation angle of the rotor; and a closing portion which is configured to close a rest of the plurality of flow holes that is other than the corresponding predetermined flow hole. The drive device is configured to output a torque which rotates the rotor.

Here, a circle, which is centered on the rotational axis of the rotor and is perpendicular to the rotational axis, is defined as an imaginary circle. An opening edge of the passage opening of the rotor has a radial section. The radial section faces in a circumferential direction of the imaginary circle and extends along an imaginary line which extends in a radial direction of the imaginary circle.

The at least one partition of the flow hole forming portion has: a parallel portion which extends in parallel with the radial direction of the imaginary circle; and a progressively varying portion which is placed on an outer side of the parallel portion in the radial direction. A width of the progressively varying portion, which is measured in the circumferential direction, is progressively increased toward the outer side in the radial direction.

With the above configuration, the valve device can communicate the corresponding predetermined flow hole among the plurality of flow holes of the flow hole forming portion to the passage opening of the rotor by rotating the rotor by the drive device while closing the rest of the plurality of flow holes that is other than the corresponding predetermined flow hole. At this time, since the at least one partition of the flow hole forming portion has the progressively varying portion, it is possible to limit the communication of the passage opening with the unintended flow hole, which is supposed to be closed. Therefore, in the valve device, it is possible that the fluid flows into the intended flow hole and does not flow into the unintended flow hole which is supposed to be closed.

In contrast, in this valve device, since the at least one partition has the parallel portion and the progressively varying portion, the passage cross-sectional area of the respective flow holes of the flow hole forming portion can be increased in comparison to the configuration, in which the partition is formed only by the parallel portion which has the large width. Thus, this valve device can improve the degree of sealing of the unintended one of the plurality of flow holes, which is not intended to conduct fluid, while limiting the increase in the pressure loss of the fluid that flows through the opened one of the plurality of flow holes.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each of the following embodiments, portions, which are the same or equivalent to each other, will be indicated by the same reference signs.

First Embodiment

A valve device of a first embodiment is used in a fluid circulation system installed on, for example, an electric vehicle or a hybrid vehicle. The fluid circulation system is a system that circulates coolant (serving as fluid) through a drive power source for driving the vehicle and a heater core for air conditioning of a vehicle cabin. For example, LLC (Long Life Coolant) containing ethylene glycol is used as the coolant. The valve device is configured to change a flow path of the coolant flowing in the system or adjust a flow rate of the coolant.

First of all, a structure of the valve device of the present embodiment will be described.

As shown inFIGS.1to4, the valve device1of the present embodiment includes a housing10, a flow hole forming portion (also referred to as a stator)20, a rotor30and a drive device40. In the present embodiment, there is described an example, in which the valve device1is formed as a five-way valve.

The housing10forms an outer shell of the valve device1and has a passage configured to conduct the fluid at an inside of the housing10. Specifically, the housing10includes a housing main body11, a fluid inlet12and four fluid outlets13-16. The housing main body11is shaped in a bottomed tubular form. The fluid inlet12and the fluid outlets13-16are communicated with an inside of the housing main body11. The fluid inlet12is located at a portion of the housing main body11, which is located on one side in an axial direction of the housing main body11, and the fluid outlets13-16are located at another portion of the housing main body11located on the other side in the axial direction. In the following description, the fluid outlets13-16will be referred to as a first fluid outlet13, a second fluid outlet14, a third fluid outlet15and a fourth fluid outlet16, respectively. The fluid outlets13-16are arranged one after another in a circumferential direction of the housing main body11.

As shown inFIG.3, the flow hole forming portion20is fixed at the passage in the housing10. The flow hole forming portion20is installed such that the flow hole forming portion20does not make a relative rotation around the axis at the passage of the housing10. As shown inFIG.5, the flow hole forming portion20of the present embodiment is shaped in a form of a circular disk. The flow hole forming portion20includes: four flow holes21-24, each of which extends through the flow hole forming portion20in a plate thickness direction of the flow hole forming portion20; and four partitions25, each of which is provided between corresponding adjacent two of the flow holes21-24. Each of the flow holes21-24is configured to conduct the fluid therethrough. The four flow holes21-24and the four partitions25are alternately arranged in the circumferential direction of the flow hole forming portion20along an entire circumferential extent of the flow hole forming portion20. Each of the flow holes21-24is shaped generally in a form of a sector. In the following description, the flow holes21-24will be referred to as a first flow hole21, a second flow hole22, a third flow hole23and a fourth flow hole24, respectively. A shape of each of the partitions25of the flow hole forming portion20will be described later.

As shown inFIG.3, the rotor30is installed at the passage of the housing10such that the rotor30is rotatable about a rotational axis Ax which is predetermined. The rotor30makes surface-to-surface contact with a surface of the flow hole forming portion20while this surface of the flow hole forming portion20is located on the one side in the plate thickness direction. As shown inFIG.7, the rotor30of the present embodiment is shaped in a form of a circular disk. The rotor30includes: a passage opening31, which extends through the rotor30in a plate thickness direction of the rotor30; and a closing portion32which is a remaining portion of the rotor30that is other than the passage opening31. The passage opening31is shaped generally in a form of a sector and can conduct the fluid therethrough. When the rotor30is rotated about the rotational axis Ax and is stopped at a corresponding predetermined position, the passage opening31of the rotor30is communicated with a corresponding one of the flow holes21-24of the flow hole forming portion20. At this time, the closing portion32of the rotor30closes the remaining three flow holes among the flow holes21-24of the flow hole forming portion20.

Here, a circle, which is centered on the rotational axis Ax of the rotor30and is perpendicular to the rotational axis Ax, is defined as an imaginary circle C. InFIG.7, the imaginary circle C is indicated by a dot-dot-dash line. In the following description, a line, which extends in a radial direction of the imaginary circle C, will be referred to as an imaginary line L.

An opening edge of the passage opening31of the rotor30has two radial sections33,34which face each other in the circumferential direction of the imaginary circle C. Each of the radial sections33,34linearly extends along the corresponding imaginary line L which extends in the radial direction of the imaginary circle C. This expression of the radial sections33,34includes a state where each of the radial sections33,34, which respectively face in the circumferential direction of the imaginary circle C at the opening edge of the passage opening31, slightly deviates from the corresponding imaginary line L which extends in the radial direction of the imaginary circle C, due to, for example, a manufacturing tolerance as long as each of the radial sections33,34substantially coincide with the corresponding imaginary line L. A circumferential section35of the opening edge of the passage opening31, which face inward in the radial direction of the imaginary circle C, is shaped in a form of an arc. A size of the passage opening31of the rotor30is set to be slightly larger than each of the flow holes21-24of the flow hole forming portion20shown inFIG.5. Specifically, an angle θ1, which is defined between the radial sections33,34facing each other in the circumferential direction of the imaginary circle C at the opening edge of the passage opening31, coincides with an angle θ2 defined between center lines of circumferentially adjacent two of the partitions25of the flow hole forming portion20. In this description, the angle, which is defined between two lines, refers to an interior angle of these two lines.

A shape of each of the four partitions25of the flow hole forming portion20will be described with reference toFIGS.5and6.

Even inFIG.5, like inFIG.7, the imaginary circle C, which is centered on the rotational axis Ax of the rotor30and is perpendicular to the rotational axis Ax, is indicated by the dot-dot-dash line. In a state where the flow hole forming portion20and the rotor30are installed in the housing10, a central axis of the flow hole forming portion20and the rotational axis Ax of the rotor30coincide with each other. Therefore, the center of the imaginary circle C and the central axis of the flow hole forming portion20coincide with each other inFIG.5.

The four partitions25of the flow hole forming portion20respectively extend in the radial direction of the imaginary circle C. The four partitions25are arranged at 90° intervals in the circumferential direction of the imaginary circle C. Specifically, inFIG.5, the angle θ2, which is defined between the center lines of each circumferentially adjacent two of the partitions25of the flow hole forming portion20, is set to be 90°. However, the arrangement of the partitions25is not limited to the arrangement shown inFIG.5and may be set to any arrangement according to, for example, a required flow rate characteristic of the flow holes.

In the following description, a line, which coincides with the center line of the corresponding partition25and extends in the radial direction of the imaginary circle C, will be referred to as a primary imaginary line L1. Furthermore, a line, which radially extends and is tilted by a predetermined angle from the primary imaginary line L1 toward the inside of the corresponding closest one of the flow holes21-24, will be referred to as a secondary imaginary line L2.

The four partitions25of the flow hole forming portion20respectively have an identical shape. As shown inFIGS.5and6, each of the partitions25has a parallel portion26and a progressively varying portion27. The parallel portion26extends in parallel with the primary imaginary line L1. The parallel portion26extends in the radial direction of the imaginary circle C such that a width of the parallel portion26is constant along an entire radial extent of the parallel portion26. The progressively varying portion27is placed on an outer side of the parallel portion26in the radial direction. A width of the progressively varying portion27, which is measured in the circumferential direction, is progressively increased toward the outer side in the radial direction.

Two peripheral edges of the parallel portion26, which are circumferentially opposite to each other, respectively have a first edge section28, which faces in the circumferential direction of the imaginary circle C. The first edge section28is spaced by a predetermined distance from the primary imaginary line L1 toward the inside of the closest one of the flow holes21-24, which is closest to the peripheral edge of the parallel portion26, and the first edge section28extends in parallel with the primary imaginary line L1. This expression of the first edge section28includes a state where the first edge section28slightly deviates from the primary imaginary line L1 due to, for example, a manufacturing tolerance as long as the first edge section28is substantially in parallel with the primary imaginary line L1.

Two peripheral edges of the progressively varying portion27, which are circumferentially opposite to each other, respectively have a second edge section29, which faces in the circumferential direction of the imaginary circle C. The second edge section29extends along the secondary imaginary line L2 described above. This expression of the second edge section29includes a state where the second edge section29slightly deviates from the secondary imaginary line L2 due to, for example, a manufacturing tolerance as long as the second edge section29is substantially in parallel with the secondary imaginary line L2.

As shown inFIG.6, an exterior angle θ3, which is defined between the first edge section28and the second edge section29(more specifically, between an imaginary extension line of the first edge section28and an imaginary extension line of the second edge section29), is the same as an angle θ4, which is defined between the primary imaginary line L1 and the secondary imaginary line L2. The exterior angle θ3, which is defined between the first edge section28and the second edge section29(i.e., the angle θ4 defined between the primary imaginary line L1 and the secondary imaginary line L2), can be arbitrarily set according to the amount of variation in the stop position of the rotor30, which is assumed be generated at the time of driving the rotor30in a forward rotation direction and a backward rotation direction. In the present embodiment, the exterior angle θ3, which is defined between the first edge section28and the second edge section29(i.e., the angle θ4 defined between the primary imaginary line L1 and the secondary imaginary line L2), is set in, for example, a range of 5° to 10°.

A location of a connection point P between the first edge section28and the second edge section29can be arbitrarily set based on the relationship between the exterior angle θ3 defined between the first edge section28and the second edge section29and the width W1 of the parallel portion26. In the present embodiment, when a radial length of the partition25is divided into three equal parts, the connection point P between the first edge section28and the second edge section29is located in a center part among the three equal parts.

As shown inFIGS.3and4, a plurality of chambers are formed at the inside of the housing main body11. Specifically, an inlet communication chamber100, which is communicated with the fluid inlet12, and first to fourth communication chambers101-104, which are respectively communicated with the first to fourth fluid outlets13-16, are formed. The inlet communication chamber100is located on the one side of the rotor30at which the fluid inlet12is placed. The first to fourth communication chambers101-104are located on the other side of the flow hole forming portion20at which the first to fourth fluid outlets13-16are placed. The first to fourth communication chambers101-104are partitioned by four partition walls17provided in the inside of the housing10. As shown inFIG.4, a wall thickness of each of the four partition walls17does not vary in both of the radial direction and the axial direction. Specifically, the wall thickness of each of the partition walls17is constant in the radial direction and the axial direction. Thereby, generation of voids and deterioration of dimensional accuracy during injection molding can be limited. The four partition walls17are respectively placed at four locations which correspond to the locations of the four partitions25of the flow hole forming portion20. An end portion18of each of the four partition walls17is fixed in a state where an orientation of the end portion18corresponds to a corresponding one of the four partitions25of the flow hole forming portion20. Therefore, the first to fourth communication chambers101-104are respectively communicated with the first to fourth flow holes21-24of the flow hole forming portion20. The flow hole forming portion20shown inFIG.5is in a state where the flow hole forming portion20is rotated by 45° in a counterclockwise direction relative to the housing10shown inFIG.4.

As shown inFIG.3, the drive device40is provided to one end portion of the housing10. The drive device40include: an electric motor41which serves as a drive power source; and a gear mechanism42which transmits a torque outputted from the electric motor41to the shaft43. The electric motor41is rotated according to a control signal outputted from an electronic control device2. The gear mechanism42includes a plurality of gears meshed with each other. The electronic control device2, which controls an operation of the electric motor41, is a computer that includes, for example, a semiconductor memory and a processor. The memory is a non-transitory tangible storage medium. The electronic control device2executes a computer program stored in the memory and also executes various control processes according to the computer program.

The drive device40and the rotor30are coupled with each other through the shaft43and a coupling member44. One end portion of the shaft43is engaged with an output gear (not shown) of the gear mechanism42of the drive device40. The other end portion of the shaft43is engaged with the coupling member44. The coupling member44and the rotor30are engaged with each other. Thereby, when the torque, which is generated by the drive device40, is transmitted to the rotor30through the shaft43and the coupling member44, the rotor30is rotated about the rotational axis Ax which is predetermined. The shaft43, the coupling member44and the rotor30are rotated about the common rotational axis Ax.

A torsion spring (serving as a first urging member)45and a compression spring (serving as a second urging member)46are provided around the shaft43.

The torsion spring45is a torsion coil spring which urges the rotor30relative to the housing10toward one side in the circumferential direction of the imaginary circle C. One end portion of the torsion spring45is anchored to the housing10or a member (e.g., the drive device40) fixed to the housing10, and the other end portion of the torsion spring45is anchored to the rotor30or a member (e.g., the coupling member44) fixed to the rotor30. In the present embodiment, the first urging member is formed by the single torsion spring45. However, the present disclosure is not limited to this, and the first urging member may be formed by a plurality of torsion springs.

The drive device40and the rotor30are coupled with each other through the shaft43and the coupling member44. Therefore, in the drive device40, a small gap for assembly is provided at each of: the meshing part between the gears of the gear mechanism42; the engaging part between the output gear of the drive device40and the shaft43; the engaging part between the shaft43and the coupling member44; and the engaging part between the coupling member44and the rotor30. By applying the urging force of the torsion spring45to the engaging part or the meshing part between the members for transmitting the torque from the drive device40to the rotor30, the rotor30is rotated in a state where the members, which form the engaging part or the meshing part, are always in contact with each other.

The compression spring46is a compression coil spring which urges the rotor30toward the flow hole forming portion20. One end portion of the compression spring46is anchored to the housing10or the member (e.g., the drive device40or the shaft43) fixed to the housing10, and the other end portion of the compression spring46is anchored to the rotor30or the member (e.g., the coupling member44) fixed to the rotor30. Due to the urging force of the compression spring46, the rotor30and the flow hole forming portion20slide relative to each other always in the state where the rotor30and the flow hole forming portion20contact with each other. Next, the operation of the valve device1will be described.

As shown inFIGS.8to11, an operation mode of the valve device1of the present embodiment can be changed among mainly four operation modes. In the following description, as indicated by a double-sided arrow in each ofFIGS.8to13, in a case where the rotor30is viewed from the drive device40side, the clockwise direction will be referred to as a forward rotation direction, and the counterclockwise direction will be referred to as the reverse rotation direction. InFIGS.8to13, in order to make the drawings easier to see, the closing portion32of the rotor30is indicated by a dot hatching, although the view of the closing portion32is not the cross-section.

First of all, as shown inFIG.8, in the first operation mode, the passage opening31of the rotor30and the first flow hole21of the flow hole forming portion20are communicated with each other. Therefore, the coolant, which flows from the fluid inlet12into the inlet communication chamber100of the housing10, flows through the passage opening31of the rotor30and the first flow hole21of the flow hole forming portion20and then flows out from the first fluid outlet13through the first communication chamber101.

Next, as shown inFIG.9, in the second operation mode, the rotor30is rotated from the position of the first operation mode by a predetermined angle (e.g., 90°) in the forward rotation direction, so that the passage opening31of the rotor30and the second flow hole22of the flow hole forming portion20are communicated with each other. Therefore, the coolant, which flows from the fluid inlet12into the inlet communication chamber100of the housing10, flows through the passage opening31of the rotor30and the second flow hole22of the flow hole forming portion20and then flows out from the second fluid outlet14through the second communication chamber102.

Next, as shown inFIG.10, in the third operation mode, the rotor30is rotated from the position of the second operation mode by the predetermined angle (e.g., 90°) in the forward rotation direction, so that the passage opening31of the rotor30and the third flow hole23of the flow hole forming portion20are communicated with each other. Therefore, the coolant, which flows from the fluid inlet12into the inlet communication chamber100of the housing10, flows through the passage opening31of the rotor30and the third flow hole23of the flow hole forming portion20and then flows out from the third fluid outlet15through the third communication chamber103.

Furthermore, as shown inFIG.11, in the fourth operation mode, the rotor30is rotated from the position of the third operation mode by the predetermined angle (e.g., 90°) in the forward rotation direction, so that the passage opening31of the rotor30and the fourth flow hole24of the flow hole forming portion20are communicated with each other. Therefore, the coolant, which flows from the fluid inlet12into the inlet communication chamber100of the housing10, flows through the passage opening31of the rotor30and the fourth flow hole24of the flow hole forming portion20and then flows out from the fourth fluid outlet16through the fourth communication chamber104.

As discussed above, the operation mode of the valve device1of the present embodiment can be changed among the first to fourth operation modes. In the above description, the operation mode of the valve device1is changed among the first to fourth operation modes by rotating the rotor30in the forward rotation direction. However, the present disclosure is not limited to this. That is, the operation mode of the valve device1may be changed among the first to fourth operation modes by rotating the rotor30in the reverse rotation direction.

Here, at the time of changing the operation mode of the valve device1among the first to fourth operation modes, a variation in the rotation angle of the rotor30relative to the rotation angle of the drive device40may possibly occur. This variation may be caused by, for example, the presence of a small gap provided for assembly at the engaging parts of the members (i.e., the gear mechanism42, the shaft43and the coupling member44) which transmit the torque from the drive device40to the rotor30. Alternatively, the variation may be caused by presence of a small gap for assembly between the housing10and the flow hole forming portion20. Further alternatively, the variation may be caused by a variation in the rotation angle of the electric motor41, or a manufacturing tolerance of the respective members.

In the valve device1of the present embodiment, in response to the occurrence of the variation in the rotation angle of the rotor30relative to the rotation angle of the drive device40, a degree of sealing of the unintended flow hole, which is not intended to conduct the fluid, can be improved, and an increase in the pressure loss of the fluid, which flows through the opened flow hole among the flow holes21-24, can be limited.

FIG.12indicates a state where the rotor30is stopped at a position, which is deviated by a predetermined angle in the forward rotation direction from a normal stop position of the rotor30, at the time when the valve device1executes the first operation mode. InFIG.12, the amount of positional deviation of the rotor30in the forward rotation direction relative to the normal stop position of the rotor30is indicated by an angle α. Even in this state, since the valve device1of the present embodiment has the progressively varying portion27at the part of the respective partitions25of the flow hole forming portion20, it is possible to limit an unintended flow of the coolant into the second flow hole22.

Furthermore,FIG.13indicates a state where the rotor30is stopped at a position, which is deviated by a predetermined angle in the reverse rotation direction from the normal stop position of the rotor30, at the time when the valve device1executes the first operation mode. InFIG.13, the amount of positional deviation of the rotor30in the reverse rotation direction relative to the normal stop position of the rotor30is indicated by an angle β. Even in this state, since the valve device1of the present embodiment has the progressively varying portion27at the part of the respective partitions25of the flow hole forming portion20, it is possible to limit an unintended flow of the coolant into the fourth flow hole24.

As discussed above, in the valve device1of the present embodiment, even in the case where the rotor30is stopped at the position, which is deviated in the forward rotation direction or the reverse rotation direction from the normal stop position of the rotor30at the time of executing any one of the first to fourth operation modes, it is possible to limit the unintended flow of the coolant into the unintended flow hole that is not intended to conduct the fluid. Specifically, the degree of sealing of the unintended flow hole, which is not intended to conduct the fluid, can be improved.

For the purpose of comparing with the valve device1of the present embodiment described above, a valve device of a comparative example will be described with reference toFIGS.15to18.FIG.15indicates only a flow hole forming portion200of the valve device of the comparative example, andFIG.16indicates only a rotor300of the valve device of the comparative example. Even inFIGS.15and16, the imaginary circle C, which is centered on the rotational axis Ax of the rotor300and is perpendicular to the rotational axis Ax, is indicated by the dot-dot-dash line. The center of the imaginary circle C and the central axis of the flow hole forming portion200coincide with each other.

As shown inFIG.15, the flow hole forming portion200of the valve device of the comparative example has four flow holes210,220,230,240and four partitions250. However, each of the four partitions250of the flow hole forming portion200of the comparative example only has the parallel portion260and does not have the progressively varying portion. Even in the comparative example, the parallel portion260extends in parallel with the primary imaginary line L1 such that the width of the parallel portion260is constant along the entire radial extent of the parallel portion260in the radial direction of the imaginary circle C. Here, it is assumed that the width W2 of the parallel portion260of the partition250of the valve device of the comparative example is the same as the width W1 of the parallel portion26of the partition25of the valve device1of the first embodiment. The width of the parallel portion260,26is a size of the parallel portion260,26measured in the circumferential direction of the imaginary circle C.

The rotor300of the valve device of the comparative example shown inFIG.16has the same structure as the rotor30of the valve device1of the first embodiment. Specifically, as shown inFIG.16, the rotor300includes: the passage opening310; and the closing portion320which is the remaining portion of the rotor300that is other than the passage opening310. Two radial sections330,340of the opening edge of the passage opening310, which face each other in the circumferential direction of the imaginary circle C, respectively linearly extend along the corresponding imaginary line L which extends in the radial direction of the imaginary circle C. The angle θ1, which is defined between the radial sections330,340facing each other in the circumferential direction of the imaginary circle C at the opening edge of the passage opening310, coincides with the angle θ2 defined between the center lines of the circumferentially adjacent two of the partitions250of the flow hole forming portion200.

FIG.17indicates a state where the rotor300is stopped at a position, which is deviated by a predetermined angle in the forward rotation direction from the normal stop position of the rotor300, at the time when the valve device of the comparative example executes the first operation mode. InFIG.17, the amount of positional deviation of the rotor300in the forward rotation direction relative to the normal stop position of the rotor300is indicated by an angle γ. The angle γ indicated inFIG.17is smaller than the angle α indicated inFIG.12described in the first embodiment. In the valve device of the comparative example, when the amount of positional deviation in the forward rotation direction relative to the normal stop position of the rotor300becomes larger than the angle γ, the unintended flow of the coolant is conducted into the second flow hole220.

Furthermore,FIG.18indicates a state where the rotor300is stopped at a position, which is deviated by a predetermined angle in the reverse rotation direction from the normal stop position of the rotor300, at the time when the valve device of the comparative example executes the first operation mode. InFIG.18, the amount of positional deviation of the rotor300in the reverse rotation direction relative to the normal stop position of the rotor300is indicated by an angle δ. The angle δ indicated inFIG.18is smaller than the angle β indicated inFIG.13described in the first embodiment. In the valve device of the comparative example, when the amount of positional deviation in the reverse rotation direction relative to the normal stop position of the rotor300becomes larger than the angle δ, the unintended flow of the coolant is conducted into the fourth flow hole240. That is, the valve device of the comparative example has a small allowable range of variation with respect to the stop position of the rotor300.

Even in the valve device of the comparative example, it is conceivable to increase the width W2 of the parallel portion260of the respective partitions250of the flow hole forming portion200to limit the unintended leakage of the fluid into the unintended flow hole, which is supposed to be closed, even in the case where the variation in the stop position of the rotor300is increased. However, in this configuration, a passage cross-sectional area of the respective flow holes210,220,230,240of the flow hole forming portion200becomes small, and thereby a pressure loss of the fluid passing through the opened flow hole among the flow holes210,220,230,240is disadvantageously increased.

In contrast to the valve device of the comparative example, the valve device1of the present embodiment provides the following actions and effects.

(1) In the valve device1of the present embodiment, each of the partitions25of the flow hole forming portion20has: the parallel portion26, which extends in parallel with the primary imaginary line L1 that extends in the radial direction of the imaginary circle C; and the progressively varying portion27, which is placed on the outer side of the parallel portion26in the radial direction.

With this configuration, at the time when the valve device1executes the predetermined operation mode, even in the case where the variation in the stop position of the rotor30occurs, since each of the partitions25of the flow hole forming portion20has the progressively varying portion27, it is possible to limit the communication of the passage opening31with the unintended flow hole, which is supposed to be closed. Therefore, at the time of executing the predetermined operation mode, it is possible that the coolant flows into the intended flow hole and does not flow into the unintended flow hole which is supposed to be closed.

Furthermore, in the valve device of the comparative example described above, it is conceivable to increase the width W2 of the parallel portion260of the respective partitions250to limit the unintended leakage of the fluid into the unintended flow hole, which is supposed to be closed, in the case where the variation in the stop position of the rotor300occurs. In contrast, in the valve device1of the present embodiment, since each of the partitions25has the parallel portion26and the progressively varying portion27, the passage cross-sectional area of the respective flow holes21-24of the flow hole forming portion20can be increased in comparison to the configuration, in which the width W2 of the parallel portion260of the respective partitions250is increased.

Therefore, in the valve device1of the present embodiment, in response to the occurrence of the variation in the stop position of the rotor30, it is possible to improve the degree of sealing of the unintended flow hole, which is supposed to be closed, among the flow holes21-24of the flow hole forming portion20, while limiting an increase in the pressure loss of the fluid, which flows through the opened flow hole among the flow holes21-24.

(2) In the present embodiment, the first edge section28of the peripheral edge of the parallel portion26, which faces in the circumferential direction of the imaginary circle C, is spaced by the predetermined distance from the primary imaginary line L1 toward the inside of the closest one of the flow holes21-24, which is closest to the peripheral edge of the parallel portion26, and the first edge section28extends in parallel with the primary imaginary line L1. Furthermore, the second edge section29of the outer periphery of the progressively varying portion27, which faces in the circumferential direction of the imaginary circle C, extends along the secondary imaginary line L2, which radially extends and is tilted by the predetermined angle from the primary imaginary line L1 toward the inside of the corresponding closest flow hole21-24.

With this configuration, when the variation in the stop position of the rotor30occurs, the corresponding radial section33,34of the opening edge of the passage opening31, which faces in the circumferential direction of the imaginary circle C, is aligned with the second edge section29of the corresponding outer periphery of the progressively varying portion27, which faces in the circumferential direction of the imaginary circle C. Therefore, the degree of sealing of the unintended flow hole21-24, which is supposed to be closed, can be improved against the variation in the stop position of the rotor30without unnecessarily increasing the width of the progressively varying portion27. Thus, in this valve device1, the passage cross-sectional area of the respective flow holes21-24of the flow hole forming portion20can be increased while limiting the increase in the pressure loss of the fluid passing through the opened flow hole among the flow holes21-24.

(3) In the present embodiment, the exterior angle θ3, which is defined between the first edge section28and the second edge section29(i.e., the angle θ4 defined between the primary imaginary line L1 and the secondary imaginary line L2), is set in the range of 5° to 10°.

According to this configuration, in the case where the exterior angle θ3, which is defined between the first edge section28and the second edge section29, is smaller than 5°, the width of the partition25becomes small. Therefore, it becomes difficult to limit the unintentional flow of the fluid into the other flow hole, which is supposed to be closed, in response to the occurrence of the variation in the stop position of the rotor30. In contrast, in the case where the exterior angle θ3, which is defined between the first edge section28and the second edge section29, is larger than 10°, the width of the partition25becomes large. Therefore, it becomes difficult to ensure the large passage cross-sectional area of the respective flow holes21-24. Thus, in this valve device1, the exterior angle θ3, which is defined between the first edge section28and the second edge section29, is set in the range of 5° to 10°, so that it is possible to improve the degree of sealing of the unintended flow hole, which is not supposed to conduct the fluid, among the flow holes21-24, and it is possible to limit an increase in the pressure loss of the fluid, which flows through the opened flow hole among the flow holes21-24.

(4) In the present embodiment, when the radial length of the partition25is divided into the three equal parts, the connection point P between the first edge section28and the second edge section29is located in the center part among the three equal parts.

In a case where the connection point P between the first edge section28and the second edge section29is located in a radially outermost part among the three equal parts, it becomes difficult to limit the unintentional flow of the fluid into the other flow hole, which is supposed to be closed, in response to the occurrence of the variation in the stop position of the rotor30. Furthermore, in a case where the connection point P between the first edge section28and the second edge section29is located in a radially innermost part among the three equal parts, it becomes difficult to ensure the large passage cross-sectional area of the respective flow holes21-24. Thus, in the valve device1, the connection point P between the first edge section28and the second edge section29is located in the center part among the three equal parts, so that the degree of sealing of the unintended flow hole, which is supposed to be closed, among the flow holes21-24can be improved, and the increase in the pressure loss of the fluid, which flows through the opened flow hole among the flow holes21-24, can be limited.

(5) In the present embodiment, the operation mode of the drive device40, in which the passage opening31is communicated with the corresponding predetermined flow hole and is blocked from the rest of the flow holes that is other than the corresponding predetermined flow hole, is changeable among two or more operation modes. In the present embodiment, there is described the example, in which the operation mode is changeable among the four operation modes.

Accordingly, in the valve device1, in which the operation mode is changeable among the two or more operation modes, it is possible to limit an unnecessary increase in the width of the partition25and/or the inner diameter of the housing10. Thus, in response to the occurrence of the variation in the stop position of the rotor30, the degree of sealing of the unintended flow hole, which is not intended to conduct the fluid, can be improved, and the increase in the pressure loss of the fluid, which flows through the opened flow hole among the flow holes21-24, can be limited.

(6) In the present embodiment, the flow holes21-24and the partitions25are alternately arranged in the circumferential direction of the imaginary circle C along the entire circumferential extent of the flow hole forming portion20.

In the case where the flow holes21-24and the partitions25are arranged along the entire circumferential extent of the flow hole forming portion20, when the width of the respective partitions25is increased, the passage cross-sectional area of the respective flow holes21-24is reduced. Thus, the pressure loss of the fluid, which flows through the opened flow hole among the flow holes21-24is increased.

In contrast, in the valve device1of the present embodiment, in the structure, in which the flow holes21-24and the partitions25are alternately arranged along the entire circumferential extent of the flow hole forming portion20, each of the partitions25has the parallel portion26and the progressively varying portion27, so that it is possible to ensure the large passage cross-sectional area of the respective flow holes21-24. Thus, in this valve device1, the improvement in the degree of sealing of the unintended flow hole, which is not intended to conduct the fluid, is achieved, and the increase in the pressure loss of the fluid conducted through the opened flow hole among the flow holes21-24is limited.

(7) The valve device1of the present embodiment includes the torsion spring (serving as the first urging member)45which urges the rotor30relative to the housing10toward the one side in the circumferential direction of the imaginary circle C.

Therefore, even in the case where the rotor30is rotated in the forward rotation direction and the reverse rotation direction, the members, which transmit the torque from the drive device40to the rotor30, are always placed in contact with each other by the urging force of the torsion spring45. This reduces the variation in the stopping position of the rotor30, so that the exterior angle θ3 defined between the first edge section28and the second edge section29(i.e., the angle θ4 defined between the primary imaginary line L1 and the secondary imaginary line L2) can be reduced. Thus, in this valve device1, the degree of sealing of the unintended flow hole, which is not intended to conduct the fluid, can be improved, and the passage cross-sectional area of the respective flow holes21-24of the flow hole forming portion20can be increased.

Second Embodiment

Next, a second embodiment will be described. The second embodiment is a modification of the first embodiment, in which the configuration of the flow hole forming portion20is changed, and the rest of the second embodiment is the same as that of the first embodiment. Therefore, only the portions, which are different from those of the first embodiment will be described in the following description.

FIG.14indicates the flow hole forming portion20, which is received in the passage of the housing10, and the cross-section of the housing10, in which the flow hole forming portion20is received, in the valve device1of the second embodiment. As shown inFIG.14, the flow hole forming portion20of the valve device1of the second embodiment also includes the four flow holes21-24and the four partitions25while each of the partitions25is placed between the corresponding adjacent two of the flow holes21-24. The four flow holes21-24and the four partitions25are alternately arranged in the circumferential direction of the flow hole forming portion20along the entire circumferential extent of the flow hole forming portion20.

However, in the second embodiment, the sizes of the respective flow holes21-24are different from each other. The sizes of the flow holes21-24are arbitrarily set according to, for example, the required flow characteristics of the respective flow holes21-24.

Even in the second embodiment, the four partitions25of the flow hole forming portion20have the identical shape. Each of the partitions25has the parallel portion26and the progressively varying portion27. The parallel portion26extends in parallel with the primary imaginary line L1 such that the width of the parallel portion26is constant along the entire radial extent of the parallel portion26in the radial direction of the imaginary circle C. The progressively varying portion27is placed on the outer side of the parallel portion26, and the width of the progressively varying portion27, which is measured in the circumferential direction, is progressively increased toward the outer side in the radial direction.

The first edge section28of the peripheral edge of the parallel portion26, which faces in the circumferential direction of the imaginary circle C, is spaced by the predetermined distance from the primary imaginary line L1 toward the inside of the closest one of the flow holes21-24, which is closest to the peripheral edge of the parallel portion26, and the first edge section28extends in parallel with the primary imaginary line L1. Furthermore, the second edge section29of the peripheral edge of the progressively varying portion27, which faces in the circumferential direction of the imaginary circle C, extends along the secondary imaginary line L2. That is, the four partitions25of the flow hole forming portion20of the second embodiment are the same as the partitions25of the flow hole forming portion20of the first embodiment except that the locations of the partitions25in the circumferential direction are different from those of the first embodiment.

The flow hole forming portion20has a positioning projection50which is formed at an outer peripheral portion of the flow hole forming portion20shaped in a circular disk form and projects toward the outer side in the radial direction. The projection50is fitted into a groove51which is formed at an inner wall of the housing10. With this configuration, the flow hole forming portion20is installed such that the flow hole forming portion20does not make relative rotation around the axis at the passage of the housing10. The shape and the number of the projection(s)50and the shape and the number of the groove(s)51may be set arbitrarily.

The valve device1of the second embodiment described above can achieve the same actions and effects as those of the first embodiment.

Other Embodiments

(1) In each of the above embodiments, the valve device1has been described as being used for the fluid circulation system installed on, for example, the electric vehicle. However, the present disclosure is not limited to this. For example, the valve device1may be used for a fluid circulation system of another type of vehicle that is other than the electric vehicle. Furthermore, the valve device1may be used for another application other than the vehicle.

(2) In each of the above embodiments, the fluid, which flows through the passage of the housing10of the valve device1, is described as the coolant. However, the present disclosure is not limited to this. This fluid may be a liquid or gas other than the coolant.

(3) In each of the above embodiments, the valve device1is described as the five-way valve. However, the present disclosure is not limited to this. The valve device1may be formed as a two-way valve, a three-way valve, a four-way valve, a six or more way valve. Specifically, the number of the flow holes21-24, the number of the partitions25of the flow hole forming portion20and the number of the passage opening(s)31of the rotor30may be set arbitrarily.

(4) In each of the above embodiments, there is described the rotor30which has the passage opening31and the closing portion32. However, the present disclosure is not limited to this. The rotor30may have a recess that is recessed in the plate thickness direction of the rotor30from the flow hole forming portion20side toward the inlet communication chamber100side. In this case, the fluid, which is supplied from a predetermined fluid outlet, may flow through a communication chamber and a predetermined flow hole communicated with the predetermined fluid outlet and then flow in the recess of the rotor30and makes a U-turn. Thereafter, this fluid may flow through another flow hole and another communication chamber and may flow out from another fluid outlet.

(5) In each of the above embodiments, the housing10and the flow hole forming portion20of the valve device1are described as the different members, respectively. However, the present disclosure is not limited to this. The housing10and the flow hole forming portion20may be formed as a single molded component which is formed integrally in one-piece.

(6) In each of the above embodiments, the shape of the flow hole forming portion20and the shape of the rotor30in the valve device1are described as the form of the circular disk. However, the present disclosure is not limited to this. The shape of the flow hole forming portion20and the shape of the rotor30in the view taken in the axial direction of the rotational axis may be any of various forms, such as a form of a polygon, or a form of a rounded polygon, in which each corner is rounded. The material of the flow hole forming portion20and the material of the rotor30may be any of various types of materials, such as resin, ceramic or metal.

(7) In each of the above embodiments, the drive device40of the valve device1is described to have the electric motor41and the gear mechanism42. However, the present disclosure is not limited to this. A rotating device, which is other than the electric motor41, may be employed for the drive device40. Furthermore, the gear mechanism42may be eliminated, and the electric motor41and the shaft43may be directly coupled with each other.

(8) In each of the above embodiments, there is described that the drive device40and the rotor30of the valve device1are coupled with each other through the shaft43and the coupling member44. However, the present disclosure is not limited to this. The drive device40and the rotor30may be directly coupled with each other.

(9) In each of the above embodiments, each of the partitions25of the flow hole forming portion20is shaped identically. However, the present disclosure is not limited to this. One or more of the partitions25may have a shape that is different from the rest of the partitions25.

(10) In the first embodiment, corners of the flow holes21-24of the flow hole forming portion20and corners of the passage opening31of the rotor30are not rounded. However, the present disclosure is not limited to this. The corners of the flow holes21-24of the flow hole forming portion20and the corners of the passage opening31of the rotor30may be rounded.

(11) In each of the above embodiments, the valve device1is described such that the fluid flows from the fluid inlet12of the housing10into the inside of the housing10and flows out from one of the four fluid outlets13-16. However, the present disclosure is not limited to this. The valve device1may be used such that the fluid flows from one of the fluid outlets13-16of the housing10into the inside of the housing10and flows out from the fluid inlet12.

(12) The present disclosure is not limited to the above-described embodiments and may be implemented in various variations. Further, the above embodiments are not unrelated to each other and can be appropriately combined unless the combination is clearly impossible. Needless to say, in each of the above-described embodiments, the elements of the embodiment are not necessarily essential except when it is clearly indicated that they are essential and when they are clearly considered to be essential in principle. In each of the above embodiments, when a numerical value such as the number, numerical value, amount, range or the like of the constituent elements of the embodiment is mentioned, the present disclosure should not be limited to such a numerical value unless it is clearly stated that it is essential and/or it is required in principle. In each of the above embodiments, when the material, the shape, the positional relationship or the like of the constituent elements of the embodiment is mentioned, the present disclosure should not be limited to the material, the shape, the positional relationship or the like unless it is clearly stated that it is essential and/or it is required in principle.