Flow path switching device

Abstract

This flow path switching device comprises a fixed member including a plurality of communicating passages and a drive member including a plurality of communicating passages, and forms a flow path by combining the communication passages of the drive member and the communication passages of the fixed member, the flow path switching device selectively switching between the plurality of flow paths by driving the drive member. The flow path switching device includes a sealing member which is provided around the communicating passages between the fixed member and the drive member, and which suppresses leakage of fluid from the communicating passages. The sealing member comprises a held portion which is held by the drive member or the fixed member, and a sliding portion which slides along the fixed member or the drive member when the drive member is being driven. The sliding portion is provided with a recessed portion formed so as to be recessed toward the held portion side. The cross-sectional outer shape of the sealing member is formed in a mountain shape having the sliding portion side as a peak and expanding laterally toward the held portion side.

Description

Flow path switching device

[0001] The present disclosure relates to a flow path switching device that switches flow paths.

[0002] Patent Document 1 discloses a switching valve in which an O-ring is disposed as a sealing member (sealing packing) between the body and the rotor inside each port.

[0003] Japanese Patent Application Laid-Open No. 2003-262281

[0004] In the switching valve of Patent Document 1, in order to prevent fluid leakage from the seal member disposed between the body and the rotor, it is necessary to increase the surface pressure of the seal member, but increasing the surface pressure of the seal member increases the sliding resistance of the seal member. Furthermore, if the sliding resistance of the seal member increases, the driving force for rotating the rotor increases, which may result in an increase in the size of the drive unit that rotates the rotor and the physical size of the device (switching valve).

[0005] Therefore, the present disclosure has been made to solve the above-mentioned problems, and aims to provide a flow path switching device that can prevent fluid leakage from the sealing member while suppressing an increase in the size of the device.

[0006] One form of the present disclosure made to solve the above problems is a flow path switching device that combines a fixed member having a plurality of communicating passages, a drive member having a plurality of communicating passages, and the communicating passages of the drive member and the fixed member to form a flow path, and selectively switches between the plurality of flow paths by driving the drive member, and is characterized in that it has a sealing member that is provided around the communicating passage between the fixed member and the drive member and suppresses leakage of fluid from the communicating passage, and the sealing member has a holding portion that is held by the drive member or the fixed member, and a sliding portion that slides against the fixed member or the drive member when the drive member is driven, and the sliding portion has a recess that is recessed toward the holding portion side, and the cross-sectional outline of the sealing member is formed in a mountain shape that has a peak on the sliding portion side and widens laterally on the holding portion side.

[0007] According to this aspect, since a recess is provided in the sliding portion, the sliding area between the sealing member and the fixed member (or the sliding member) can be reduced, and the surface pressure of the sealing member acting on the fixed member (or the sliding member) can be increased.

[0008] Furthermore, since the cross-sectional outer shape of the sealing member is formed in a mountain shape, the sealing member is more likely to bend toward the holding portion, thereby reducing the sliding resistance of the sealing member (i.e., the sliding resistance that occurs between the sealing member and the fixed member (or sliding member)).

[0009] Therefore, the sliding resistance of the seal member can be reduced while ensuring the necessary surface pressure. Therefore, the driving force required to drive the drive member can be reduced, and the size of the drive unit that drives the drive member can be reduced. Therefore, the flow path switching device can prevent fluid leakage from the seal member while preventing the device from being increased in size.

[0010] In the above aspect, it is preferable that the sealing member has two legs formed by branching at least two ways toward the holding portion side, and a hollow portion formed inside the two legs.

[0011] According to this aspect, the seal member is more likely to bend toward the holding portion. This reduces the variation in the reaction force of the seal member (i.e., the reaction force that the seal member exerts on the fixed member (or the sliding member)) relative to changes in the amount of compression of the seal member (i.e., the amount by which the seal member is compressed by the fixed member (or the sliding member)). This stabilizes the magnitude of the sliding resistance of the seal member.

[0012] In the above aspect, it is preferable that, in the cross section of the sealing member, convex portions are formed on both sides of the concave portion in the sliding portion, and the hollow portion exists on an imaginary straight line drawn from the apex of the convex portion toward the holding portion side.

[0013] According to this aspect, the seal member can be more easily deflected toward the holding portion, which more reliably reduces variations in the reaction force of the seal member in response to changes in the amount of compression of the seal member, thereby more reliably stabilizing the magnitude of the sliding resistance of the seal member.

[0014] In the above aspect, it is preferable that the seal member has a pressure relief hole that connects the cavity with the outside of the seal member.

[0015] According to this aspect, when the cavity is filled with liquid and the seal member is crushed by the fixed member (or the sliding member), the liquid in the cavity is discharged to the outside of the seal member through the pressure relief hole. This prevents the legs from spreading laterally due to the liquid pressure in the cavity. This allows the reaction force of the seal member to be maintained stably low, thereby maintaining the sliding resistance of the seal member stably low.

[0016] In the above aspect, it is preferable that the pressure relief hole is provided in a portion of the seal member opposite to the communication passage.

[0017] According to this aspect, the pressure relief hole is less susceptible to the influence of the liquid flowing through the communication passage, so that the sliding resistance can be more stably maintained at a low level.

[0018] In the above aspect, it is preferable that the driving member or the fixed member has a groove for holding the holding portion of the sealing member, and a groove protrusion provided in the groove and positioned within the hollow portion.

[0019] According to this aspect, even if the seal member moves due to the sliding resistance of the seal member when the drive member is driven, the movement of the seal member is suppressed by the groove protrusions, and therefore stress concentration on the seal member due to the movement and deformation of the seal member is suppressed.

[0020] Furthermore, because the groove protrusions prevent the seal members from moving, when two seal members are adjacent to each other, they can be prevented from interfering with each other without the need for a partition wall (partition wall) between them, which prevents the device from becoming larger in size due to the need to provide a partition wall between the two seal members.

[0021] In the above aspect, it is preferable that the cross-sectional outer shape of the groove convex portion is formed in a curved shape such that the curvature gradually increases from the base portion to the tip portion of the groove convex portion.

[0022] According to this aspect, when the sealing member is deformed due to the sliding resistance of the sealing member when the driving member is driven, the area of ​​contact between the leg portion of the sealing member and the groove convex portion can be expanded, thereby preventing stress from concentrating at the contact portion between the leg portion of the sealing member and the groove convex portion.

[0023] In the above aspect, it is preferable that the cross-sectional outline of the groove convex portion has a vertical portion near the base of the groove convex portion, and is formed into a curved shape such that the curvature gradually increases from the vertical portion toward the tip of the groove convex portion.

[0024] According to this aspect, the surface pressure of the legs of the sealing member can be reliably applied to the vertical portions of the groove convexities, so that the legs of the sealing member can be held by the vertical portions of the groove convexities, thereby preventing the sealing member from separating from the groove convexities and falling.

[0025] In the above aspect, it is preferable that the sealing member is formed in a track shape with the driving direction of the driving member being the longitudinal direction, and is provided with first sealing portions at both ends in the longitudinal direction and second sealing portions that integrally connect the two first sealing portions, and that the compression allowance of the first sealing portions is greater in the inner portion of the track shape than in the outer portion of the track shape.

[0026] According to this aspect, it is possible to suppress unevenness in the surface pressure of the seal member between the inner portion of the track shape and the outer portion of the track shape in the first seal portion.

[0027] In the above aspect, it is preferable that the driving member rotates around a predetermined rotation axis, the sealing member is formed in a track shape with the driving direction of the driving member being the longitudinal direction, and is provided with first sealing portions at both ends in the longitudinal direction and second sealing portions that integrally connect the two first sealing portions, and that the compression allowance of the second sealing portion is greater in the portion on the rotation axis side than in the portion opposite the rotation axis.

[0028] According to this aspect, it is possible to suppress unevenness in the surface pressure of the seal member between the portion of the second seal portion on the rotary shaft side and the portion on the opposite side of the rotary shaft.

[0029] In the above aspect, the flow path switching device is preferably used in a cooling system for an electric vehicle.

[0030] According to the flow path switching device of the present disclosure, it is possible to prevent fluid leakage from the seal member while suppressing an increase in the size of the device.

[0031] 14. A perspective view of a flow path switching device of the first embodiment. A front view of a flow path switching device of the first embodiment. A plan view of a flow path switching device of the first embodiment. A bottom view of a flow path switching device of the first embodiment. An exploded perspective view of a flow path switching device of the first embodiment. A cross-sectional view taken along A-A in FIG. 2. A cross-sectional view taken along B-B in FIG. 3. A perspective view of the inside of an upper housing. A perspective view of a first rotating disk. A plan view of the first rotating disk. A bottom view of the first rotating disk. A perspective view of the first rotating disk cut along line CC in FIG. 10. A perspective view of a second rotating disk. A plan view of the second rotating disk. A bottom view of the second rotating disk. A perspective view of the second rotating disk cut along line D-D in FIG. 14. A perspective view of a rotation shaft. A cross-sectional view taken along E-E in FIG. 17. A cross-sectional view taken along F-F in FIG. 2. A schematic view of a cross-section taken along G-G in FIG. 2 showing the rotational position of the first rotating disk relative to the upper housing for the "first pattern" of the flow path switching pattern. 2B is a schematic diagram of the H-H cross section of FIG. 2 showing the rotational position of the second rotating disk relative to the lower housing for the "first pattern" of the flow path switching pattern. FIG. 2C is a schematic diagram equivalent to FIG. 20 showing the rotational position of the first rotating disk relative to the upper housing for the "second pattern" of the flow path switching pattern. FIG. 2D is a schematic diagram equivalent to FIG. 21 showing the rotational position of the second rotating disk relative to the lower housing for the "second pattern" of the flow path switching pattern. FIG. 2F is a cross-sectional view of the sealing member of the first embodiment. FIG. 2G is a diagram showing evaluation results of the deformation amount and reaction force of the sealing member. FIG. 2H is a diagram showing a state in which the sealing member is placed in water such as cooling water. FIG. 2I is a diagram explaining a problem in which the legs spread sideways. FIG. 2J is a diagram showing that pressure relief holes are provided in the legs. FIG. 2J is a diagram showing that pressure relief holes are provided in the first rotating disk as a modified example. FIG. 2F is a cross-sectional view of the sealing member of the modified example. FIG. 2G is an exploded perspective view of the flow path switching device of the second embodiment. FIG. 2H is a cross-sectional view of the flow path switching device of the second embodiment. FIG. 2H is a top view of the rotating disk. FIG. 2I is a top view of the fixed disk. FIG. 2I is an image diagram schematically showing flow path pattern A. 38 is an image diagram that schematically shows a flow path pattern B. FIG. 39 is a diagram showing a case where two upper seal members are arranged adjacent to each other in a first example of the second embodiment. FIG. 39 is an enlarged view of a portion where two upper seal members are adjacent to each other. FIG. 39 is a cross-sectional view taken along II in FIG. 38.40 , showing the state when the upper seal member has moved to the right side of the drawing. This figure corresponds to FIG. 42 and shows the state when the rotary disk has rotated. This figure is a cross-sectional view showing an enlarged view of the periphery of the holding portion of the lower seal member in a third example of the second embodiment. This figure is a cross-sectional view showing the cross-section of the lower seal member and a cross-section of its periphery in a third example of the second embodiment, showing the state when the lower seal member reaches the fixed passage as the rotary disk rotates. This figure corresponds to FIG. 45 and shows the state when the lower seal member has been released into the fixed passage. This figure is a cross-sectional view of the lower seal member and its periphery in a fourth example of the second embodiment. This figure is a cross-sectional view taken along J-J in FIG. 47 . This figure is a cross-sectional view of the upper seal member and a cross-section of its periphery in a fifth example of the second embodiment. This figure is a cross-sectional view taken along K-K in FIG. 49 . This figure is a cross-sectional view taken along L-L in FIG. 50 . This figure is a cross-sectional view corresponding to FIG. 51 in a sixth example of the second embodiment. This figure is a view showing the upper seal member and a rotary slot in a seventh example of the second embodiment. This figure is a cross-sectional view taken along M-M in FIG. 53 . This figure is a cross-sectional view taken along N-N in FIG. 53 . FIG. 53 is a cross-sectional view taken along line O-O in FIG. 53. FIG. 53 is a cross-sectional view taken along line P-P in FIG. 53. FIG. 54 is a cross-sectional view corresponding to FIG. 55 in the eighth example of the second embodiment. FIG. 55 is a cross-sectional view corresponding to FIG. 56 in the eighth example of the second embodiment. FIG. 57 is a cross-sectional view corresponding to FIG. 57 in the eighth example of the second embodiment. FIG. 58 is a diagram for explaining the problem of the second example of the second embodiment. FIG. 59 is a diagram for explaining the problem of the second example of the second embodiment. FIG. 60 is a diagram for explaining the problem of the seventh and eighth examples of the second embodiment. FIG. 61 is a diagram for explaining the problem of the seventh and eighth examples of the second embodiment. FIG. 62 is a diagram for explaining an example in which a sealing member is held by a fixing member.

[0032] An embodiment of a flow path switching device according to the present disclosure will be described. The flow path switching device according to the present disclosure is used, for example, as a device for switching a flow path of coolant in a cooling system of an electric vehicle.

[0033] First Embodiment First, a flow path switching device 1 according to a first embodiment will be described.

[0034] 1 to 7, the flow path switching device 1 includes a housing 2, a valve body unit 3 arranged inside the housing 2, a drive unit 4 that drives the valve body unit 3, and a control unit 5 that controls the drive unit 4. Note that the control unit 5 is not shown in FIGS.

[0035] [Regarding the Housing] As shown in FIGS. 1 to 7 , the housing 2 includes an upper housing 11 and a lower housing 12, and is configured by fastening the upper housing 11 and the lower housing 12 together with a plurality of screws 6. The housing 2 is provided with an inflow / outflow passage 20 through which a fluid (e.g., a liquid (water such as cooling water)) flows in and out. The upper housing 11 and the lower housing 12 are each an example of a "fixed member" in the present disclosure. The inflow / outflow passage 20 is also an example of a "communication passage (provided in the fixed member)" in the present disclosure.

[0036] The flow path switching device 1 of this embodiment is configured as an eight-way valve, for example, and the housing 2 has eight inlet / outlet passages 20. As the eight inlet / outlet passages 20, a first inlet / outlet passage 21, a second inlet / outlet passage 22, a third inlet / outlet passage 23, and a fourth inlet / outlet passage 24 are provided in the upper housing 11, and a fifth inlet / outlet passage 25, a sixth inlet / outlet passage 26, a seventh inlet / outlet passage 27, and an eighth inlet / outlet passage 28 are provided in the lower housing 12.

[0037] As shown in Fig. 8, an opening 21a of the first inflow / outflow passage 21, an opening 22a of the second inflow / outflow passage 22, an opening 23a of the third inflow / outflow passage 23, and an opening 24a of the fourth inflow / outflow passage 24 are opened inside the upper housing 11. Similarly, as shown in Fig. 5, openings 25a, 26a, 27a, and 28a of the fifth inflow / outflow passage 25 to the eighth inflow / outflow passage 28 are opened inside the lower housing 12. The housing 2 is formed of, for example, resin.

[0038] [Regarding the Valve Disk] As shown in Figures 5 to 7, the valve disk 3 rotates inside the housing 2 and includes a first rotating disk 13 and a second rotating disk 14 that are stacked adjacent to each other vertically, and a rotating shaft 15 that drives the first rotating disk 13 and the second rotating disk 14 to rotate. The first rotating disk 13 and the second rotating disk 14 are stacked in the axial direction X. The first rotating disk 13 and the second rotating disk 14 are each an example of a "driving member" in the present disclosure. The first rotating disk 13, the second rotating disk 14, and the rotating shaft 15 are formed, for example, from resin.

[0039] [Regarding the First Rotating Disk] As shown in FIGS. 5 to 7 , the first rotating disk 13 is accommodated inside the housing 2 together with the second rotating disk 14. As shown in FIGS. 9 to 12 , the first rotating disk 13 is formed in a generally cylindrical shape with a bottom and includes two rotation passages 30 that open upward in the axial direction X. The first rotating disk 13 includes the two rotation passages 30, a first rotation passage 31 and a second rotation passage 32. The rotation passages 30 are formed in a semicircular arc shape in a plan view. The rotation passages 30 are an example of a "communication passage (provided in the drive member)" in the present disclosure. A first shaft hole 13a, through which the rotating shaft 15 passes, is formed in the center of the first rotating disk 13. Furthermore, a first boss 13b is formed in the first rotating disk 13, centered on the first shaft hole 13a.

[0040] [Regarding the Second Rotating Disk] As shown in FIGS. 13 to 16 , the second rotating disk 14 is formed in a generally cylindrical shape with a bottom, similar to the first rotating disk 13, and includes two rotational passages 40 that open downward in the axial direction X. The second rotating disk 14 includes two rotational passages 40, a third rotational passage 43 and a fourth rotational passage 44. These rotational passages 40 are semicircular arc-shaped in a bottom view. These rotational passages 40 are an example of a "communication passage (provided in the drive member)" in the present disclosure. A second shaft hole 14a, through which the rotating shaft 15 passes, is also formed in the center of the second rotating disk 14. Furthermore, as shown in FIG. 14 , a second boss 14b is formed on the upper surface of the second rotating disk 14, centered around the second shaft hole 14a.

[0041] [Regarding the Rotating Shaft] As shown in Figures 17 and 18, the rotating shaft 15 of this embodiment is formed in multiple stages with different outer diameters. The upper end 15a of the rotating shaft 15, which is connected to the drive unit 4, is a gear with multiple teeth. The lower end 15b of the rotating shaft 15, which is fitted into the shaft hole 12a of the lower housing 12, has a small diameter and an irregular shape. A pair of first and second protrusions 15c and 15d are arranged on the same circumference on the outer periphery of the middle part of the rotating shaft 15. As shown in Figure 18, the first and second protrusions 15c and 15d protrude in an arc shape from the outer periphery of the rotating shaft 15 and are arranged 180 degrees apart. The first protrusion 15c has a longer circumferential length than the second protrusion 15d. Here, the first protrusion 15c and the second protrusion 15d are preferably arranged in two or more locations to ensure stable engagement with the first rotating disk 13 and the second rotating disk 14, and it is also desirable that they be arranged and shaped asymmetrically to prevent incorrect assembly.

[0042] 5 to 7, the rotating shaft 15 is provided to penetrate the upper housing 11, the first rotating disk 13, and the second rotating disk 14. The upper end 15a of the rotating shaft 15 penetrates the through-hole 11a of the upper housing 11 and is connected to the drive unit 4, and the lower end 15b is rotatably supported by the shaft hole 12a of the lower housing 12.

[0043] As shown in FIGS. 6 and 7 , a bearing 51 that rotatably supports the rotary shaft 15 is provided in the through-hole 11a of the upper housing 11. A washer 52 is provided at the upper end opening of the through-hole 11a, centered on the rotary shaft 15. The washer 52 is held in place by an E-ring 53 fixed on the rotary shaft 15. A compression spring 54 is provided on the rotary shaft 15 between the bearing 51 and the washer 52. The compression spring 54 biases the rotary shaft 15 upward in the axial direction X, preventing rattling due to vibration of the rotary shaft 15. The bearing 51 supports the rotary shaft 15 with its inner ring, thereby smoothing the rotation of the rotary shaft 15. The bearing 51 also supports the compression spring 54 with its inner ring, thereby smoothing the rotation of the compression spring 54. A lip seal 55 that prevents fluid leakage is provided in the through-hole 11a between the upper housing 11 and the rotary shaft 15. The rotary shaft 15 may be made of metal.

[0044] 6 and 7, a torsion spring 56 is provided inside the shaft hole 12a of the lower housing 12, centered on the lower end 15b of the rotary shaft 15. The torsion spring 56 is interposed between the bottom of the shaft hole 12a and the middle part of the rotary shaft 15, and urges the rotary shaft 15 in the rotational direction Y, thereby eliminating rattle between the rotary shaft 15 and the drive unit 4.

[0045] [Regarding the Rotational Transmission Mechanism] The flow path switching device 1 of this embodiment has a rotational transmission mechanism for transmitting the rotational force of the rotating shaft 15 to the first rotating disk 13 and the second rotating disk 14. The rotational transmission mechanism of this embodiment is provided between the rotating shaft 15 and the first rotating disk 13 and the second rotating disk 14, and is configured to allow relative movement of the first rotating disk 13 and the second rotating disk 14 in the axial direction X of the rotating shaft 15, and to be able to partially release the transmission of the rotational force of the rotating shaft 15 to the first rotating disk 13 and the second rotating disk 14 as the rotating shaft 15 rotates.

[0046] In this embodiment, the first rotating disk 13, the second rotating disk 14, and the rotating shaft 15 are connected to each other so as to be relatively movable in the rotational direction Y and the axial direction X. That is, as shown in FIG. 19 , the rotating shaft 15 is assembled to the first boss 13b of the first rotating disk 13 so as to coincide with the center of the first boss 13b. As shown in FIGS. 11 , 12 , and 19 , the first boss 13b has a pair of first notches 13c, 13d that are missing portions in the circumferential direction. As shown in FIG. 19 , a first protrusion 15c and a second protrusion 15d are fitted into these first notches 13c, 13d. A gap 16 is provided in the circumferential direction between the first notches 13c, 13d and the first protrusion 15c and the second protrusion 15d. Therefore, the rotating shaft 15 and the first rotating disk 13 are allowed to move relatively in the axial direction X along the first notches 13c, 13d and the protrusions 15c, 15d, and are allowed to move relatively in the rotational direction Y within the range of gaps 16 between the first notches 13c, 13d and the protrusions 15c, 15d. In this way, the rotating shaft 15 is connected to the first rotating disk 13 so as to be able to move relatively in the rotational direction Y and the axial direction X.

[0047] On the other hand, similar to the first rotating disk 13, the rotating shaft 15 is assembled to the second boss 14b of the second rotating disk 14 so as to coincide with the center of the second boss 14b. Similar to the first boss 13b, the second boss 14b has a pair of second notches 14c, 14d, which are missing portions of the second boss 14b in the circumferential direction, as shown in FIGS. 14 and 16 . The first protrusion 15c and the second protrusion 15d are fitted into the second notches 14c, 14d. Circumferential gaps are also provided between the second notches 14c, 14d and the protrusions 15c, 15d. Therefore, the rotating shaft 15 and the second rotating disk 14 are allowed to move relative to each other in the axial direction X along the second notches 14c, 14d and the protrusions 15c, 15d, and are allowed to move relative to each other in the rotational direction Y within the range of the gaps between the second notches 14c, 14d and the protrusions 15c, 15d. In this way, the rotary shaft 15 is connected to the second rotary disk 14 so as to be movable relative to the second rotary disk 14 in the rotational direction Y and the axial direction X.

[0048] The rotating shaft 15 rotates by receiving driving force from the drive unit 4, and rotates relative to each other within the gap 16 at each boss 13b, 14b, and rotates integrally with the first rotating disk 13 and the second rotating disk 14 by engaging with the circumferential inner surfaces of each first notch 13c, 13d and each second notch 14c, 14d.

[0049] [Regarding the sealing members] As shown in Figures 5 to 7, 9, 10, and 15, in this embodiment, a first sealing member 17 and a second sealing member 18 are provided between the first rotating disk 13 and the housing 2 (the upper housing 11 and the lower housing 12) and between the second rotating disk 14 and the housing 2 (the upper housing 11 and the lower housing 12). The first sealing member 17 is provided on the first rotating disk 13, and the second sealing member 18 is provided on the second rotating disk 14. That is, as shown in Figures 9 and 10, a surrounding groove 13e is formed on the upper surface of the first rotating disk 13 so as to surround the peripheries of the openings of the two rotational passages 30 (the first rotational passage 31 and the second rotational passage 32). The first sealing member 17 is fitted into and fixed in the surrounding groove 13e and is provided so as to protrude from the upper surface of the first rotating disk 13. 15 and 16 , a surrounding groove 14e is formed on the underside of the second rotating disk 14 so as to surround the periphery of the openings of the two rotational passages 40 (the third rotational passage 43 and the fourth rotational passage 44). The second seal member 18 is fitted and fixed in the surrounding groove 14e and is provided so as to protrude from the underside of the second rotating disk 14. In this embodiment, the first seal member 17 and the second seal member 18 are formed only from rubber. The first seal member 17 and the second seal member 18 may also be formed from a fluororesin (e.g., Teflon (registered trademark)) or from rubber to which a fluororesin is attached.

[0050] [Regarding the drive unit] The drive unit 4 includes a motor or the like (not shown) for applying a rotational driving force to the rotary shaft 15. The flow path switching device 1 selectively switches and forms a plurality of flow paths by combining and connecting the rotational passage 30 of the first rotating disk 13, the rotational passage 40 of the second rotating disk 14, and the inflow / outflow passages 20 (first inflow / outflow passage 21 to eighth inflow / outflow passage 28) of the housing 2, by driving the first rotating disk 13 and the second rotating disk 14 to rotate via the rotary shaft 15 with the drive unit 4, thereby forming a plurality of "flow path switching patterns" (described later).

[0051] [Regarding the Control Unit] The control unit 5 controls the drive unit 4 to rotate the rotary shaft 15 to rotate the first rotary disk 13 and the second rotary disk 14 and switch the flow paths.

[0052] [Regarding the Flow Path Switching Pattern] An example of a flow path switching pattern will now be described. FIG. 20 shows the rotational position of the first rotating disk 13 relative to the upper housing 11 in a schematic diagram of the G-G cross section of FIG. 2, relating to a "first pattern" of the flow path switching pattern. In FIG. 20, the outline of the upper housing 11, which is not shown in the cross section, is shown by a two-dot chain line. FIG. 21 shows the rotational position of the second rotating disk 14 relative to the lower housing 12 in a schematic diagram of the H-H cross section of FIG. 2, relating to the "first pattern." In FIG. 21, the outline of the lower housing 12, which is not shown in the cross section, is shown by a two-dot chain line. FIG. 22 shows the rotational position of the first rotating disk 13 relative to the upper housing 11 in a schematic diagram equivalent to FIG. 20, relating to a "second pattern" of the flow path switching pattern. FIG. 23 shows the rotational position of the second rotating disk 14 relative to the lower housing 12 in a schematic diagram equivalent to FIG. 21, relating to the "second pattern."

[0053] 20 and 21 , depending on the rotational positions of the first rotating disk 13 and the second rotating disk 14, the first rotational passage 31 of the first rotating disk 13 communicates with the first inflow / outflow passage 21 and the second inflow / outflow passage 22, and the second rotational passage 32 communicates with the third inflow / outflow passage 23 and the fourth inflow / outflow passage 24. Furthermore, the third rotational passage 43 of the second rotating disk 14 communicates with the fifth inflow / outflow passage 25 and the sixth inflow / outflow passage 26, and the fourth rotational passage 44 communicates with the seventh inflow / outflow passage 27 and the eighth inflow / outflow passage 28. In this state, as shown by the arrows in FIG. 20 , the fluid that has flowed into the first inflow / outflow passage 21 flows out from the second inflow / outflow passage 22 via the first rotational passage 31, and the fluid that has flowed into the fourth inflow / outflow passage 24 flows out from the third inflow / outflow passage 23 via the second rotational passage 32. Furthermore, as shown by the arrows in Figure 21, the fluid that flows into the sixth inflow / outflow passage 26 flows out from the fifth inflow / outflow passage 25 via the third rotation passage 43, and the fluid that flows into the seventh inflow / outflow passage 27 flows out from the eighth inflow / outflow passage 28 via the fourth rotation passage 44.

[0054] 22 and 23 , in the second pattern, the first rotating disk 13 and the second rotating disk 14 rotate counterclockwise by approximately 60° from the state of the first pattern, and the first rotation passage 31 of the first rotating disk 13 communicates with the first inflow / outflow passage 21 and the third inflow / outflow passage 23, and the second rotation passage 32 communicates with the second inflow / outflow passage 22 and the fourth inflow / outflow passage 24. In addition, the third rotation passage 43 of the second rotating disk 14 communicates with the fifth inflow / outflow passage 25 and the sixth inflow / outflow passage 26, and the fourth rotation passage 44 communicates with the seventh inflow / outflow passage 27 and the eighth inflow / outflow passage 28. In this state, as shown by the arrows in FIG. 22 , the fluid that has flowed into the first inflow / outflow passage 21 flows out from the third inflow / outflow passage 23 via the first rotation passage 31, and the fluid that has flowed into the fourth inflow / outflow passage 24 flows out from the second inflow / outflow passage 22 via the second rotation passage 32. As shown by the arrows in Figure 23, the fluid that flows into the seventh inflow / outflow passage 27 flows out from the eighth inflow / outflow passage 28 via the fourth rotation passage 44, and the fluid that flows into the sixth inflow / outflow passage 26 flows out from the fifth inflow / outflow passage 25 via the third rotation passage 43.

[0055] [Details of the sealing member] Next, the details of the sealing member of this embodiment (i.e., the first sealing member 17 and the second sealing member 18) will be described. However, since the first sealing member 17 and the second sealing member 18 have the same structure, the first sealing member 17 will be described here as a representative.

[0056] In order to reduce the amount of leakage of fluid (e.g., liquid (water such as cooling water)) from the first seal member 17, it is necessary to increase the surface pressure of the first seal member 17. However, increasing the surface pressure of the first seal member 17 increases the sliding resistance of the first seal member 17. As a result, the driving force for rotating the first rotating disk 13 increases, and the driving torque of the motor provided in the drive unit 4 must be increased, which increases the size of the motor, and there is a risk that the size of the flow path switching device 1 will also increase.

[0057] The "surface pressure of the first seal member 17" refers to the pressure per unit area acting from the first seal member 17 to the upper housing 11. The "sliding resistance of the first seal member 17" refers to the sliding resistance that occurs between the first seal member 17 and the upper housing 11 when the first rotating disk 13 rotates and the first seal member 17 slides on the upper housing 11.

[0058] In this embodiment, the flow path switching device 1 is designed to have a unique structure for the first seal member 17 in order to prevent fluid leakage from the first seal member 17 while suppressing an increase in the size of the device.

[0059] 24 , the sliding portion 62 of the first seal member 17 is provided with a recess 63 recessed toward the holding portion 61. This reduces the contact area between the sliding portion 62 of the first seal member 17 and (the inner surface of) the upper housing 11, thereby increasing the surface pressure of the first seal member 17. The holding portion 61 is a portion that is held by the first rotating disk 13. The sliding portion 62 is a portion that slides on the upper housing 11 when the first rotating disk 13 is driven.

[0060] 24, the cross-sectional outline of the first seal member 17 is formed in a mountain shape with the top facing the sliding portion 62 and widening laterally toward the holding portion 61. This makes it easier for the first seal member 17 to bend toward the holding portion 61, thereby reducing the reaction force of the first seal member 17 and reducing the sliding resistance of the first seal member 17.

[0061] The "transverse cross section of the first seal member 17" refers to a cross section perpendicular to the circumferential direction of the first seal member 17. The "reaction force of the first seal member 17" refers to a reaction force acting from the first seal member 17 to the upper housing 11.

[0062] According to the results of an evaluation conducted by the applicant, as shown in Fig. 25, it was found that the reaction force of the first seal member 17 (the value shown by the solid line in Fig. 25) was reduced by 32% compared to the reaction force when an O-ring was used instead of the first seal member 17 (the value shown by the dashed line in Fig. 25). Note that the reaction force of the first seal member 17 and the reaction force when an O-ring is used here refer to the reaction force when the surface pressure of the first seal member 17 and the surface pressure of the O-ring are the same.

[0063] In this way, in this embodiment, it is possible to suppress sliding resistance while ensuring the necessary surface pressure for the first seal member 17. Therefore, it is possible to suppress the driving force required to rotate the first rotating disk 13, and therefore it is possible to suppress an increase in the size of the motor of the drive unit 4 that rotates the first rotating disk 13. Therefore, it is possible to prevent fluid leakage from the first seal member 17 for the flow path switching device 1 while suppressing an increase in the size of the device.

[0064] 24, the first seal member 17 has legs 64 and a cavity 65. The legs 64 are formed so as to branch into two parts toward the holding portion 61, and two legs 64 are provided. The cavity 65 is formed inside the two legs 64. It is sufficient that the first seal member 17 is formed so as to branch into at least two parts toward the holding portion 61.

[0065] In this embodiment, since a space is created inside the first seal member 17 in this manner, the first seal member 17 is more likely to bend toward the retaining portion 61 (i.e., downward). This reduces the variation in the reaction force of the first seal member 17 (i.e., the reaction force that the first seal member 17 exerts on the upper housing 11) relative to changes in the amount of compression of the first seal member 17 (i.e., the amount by which the first seal member 17 is compressed by the upper housing 11). This therefore stabilizes the magnitude of the sliding resistance of the first seal member 17.

[0066] In addition, in this embodiment, as shown in Figure 24, in the cross section of the first seal member 17, two convex portions 66 are formed on both sides of the concave portion 63 in the sliding portion 62, and a hollow portion 65 exists on an imaginary straight line VL drawn from the vertex 66a of the convex portion 66 toward the holding portion 61 side (directly below in Figure 24).

[0067] This more reliably allows the first seal member 17 to bend easily toward the holding portion 61. Therefore, it is possible to more reliably reduce the variation in the reaction force of the first seal member 17 in response to changes in the amount of compression of the first seal member 17. Therefore, the magnitude of the sliding resistance of the first seal member 17 is more reliably stabilized.

[0068] Furthermore, in this embodiment, water such as cooling water can be stored in the recess 63, which makes it easier for water to get in between the protrusion 66 of the sliding portion 62 and the upper housing 11, thereby forming a liquid film. Therefore, even if the liquid film between the protrusion 66 and the upper housing 11 is broken (i.e., the liquid film disappears), a liquid film can be formed between the protrusion 66 and the upper housing 11 simply by rotating the first rotating disk 13 slightly (i.e., by a small angle), so that the sliding resistance of the first seal member 17 can be suppressed.

[0069] Furthermore, in this embodiment, two protrusions 66 are formed on both sides of the recess 63, so that the sliding portion 62 of the first seal member 17 and the upper housing 11 come into contact at two points. Therefore, even if the sealing performance of one of the two protrusions 66 is reduced (for example, due to the ingress of foreign matter), the sealing performance can be ensured by the other protrusion 66. Therefore, water in the rotation passage 30 is unlikely to leak out of the first seal member 17.

[0070] Furthermore, as shown in Fig. 26, when the first seal member 17, which is placed in water such as cooling water, is crushed by the upper housing 11, the volume of the water in the cavity 65 of the first seal member 17 does not change, so the legs 64 may be deformed by the water pressure in the cavity 65, as shown in Fig. 27. This may make it impossible to maintain a stable, low reaction force of the first seal member 17.

[0071] Therefore, as shown in FIG. 28, a pressure relief hole 67 may be provided to connect the cavity 65 to the outside of the first seal member 17.

[0072] As a result, when the cavity 65 is filled with water such as cooling water and the first seal member 17 is crushed by the upper housing 11, the water in the cavity 65 is discharged to the outside of the first seal member 17 through the pressure relief hole 67. This prevents the legs 64 from spreading laterally due to the water pressure in the cavity 65. Therefore, the reaction force of the first seal member 17 can be kept stably low, and the sliding resistance of the first seal member 17 can be kept stably low.

[0073] Furthermore, it is preferable that the pressure relief hole 67 be provided on the opposite side of the first seal member 17 from the rotational passage 30 (the left side in FIG. 28 ). This makes the pressure relief hole 67 less susceptible to the influence of water flowing from the rotational passage 30, so that the reaction force of the first seal member 17 can be maintained more stably at a low level.

[0074] As a modified example, a pressure relief hole 67 may be provided in the first rotating disk 13, as shown in Fig. 29. In the example shown in Fig. 29, two pressure relief holes 67 are provided, the first pressure relief hole 67 being provided in a position below the leg portion 64 of the first seal member 17 on the bottom surface of the surrounding groove 13e, and the second pressure relief hole 67 being provided from the bottom surface of the surrounding groove 13e through the first rotating disk 13 to the outside of the first rotating disk 13. Note that depending on the size of the first seal member 17 (the outer peripheral length and the volume of the cavity 65) and the size (diameter) of the pressure relief hole 67, it may be sufficient to provide one pressure relief hole 67, or three or more pressure relief holes 67 may need to be provided.

[0075] In this way, by providing a pressure relief hole 67 in the first rotating disk 13, there is no need to provide a pressure relief hole 67 in which stress can be concentrated in the first seal member 17, and therefore the load generated in the first seal member 17 can be reduced.

[0076] The pressure relief holes 67 may be provided in both the first seal member 17 and the first rotary disk 13 .

[0077] Furthermore, by providing the pressure relief holes 67 in the first seal member 17 or the first rotating disk 13 as described above, air remaining in the cavity 65 during assembly of the flow path switching device 1 is discharged to the outside of the first seal member 17 through the pressure relief holes 67. This prevents air from remaining in the cavity 65, thereby suppressing changes in the internal pressure of the cavity 65 due to temperature changes and suppressing the effect of temperature changes on the seal surface pressure (i.e., the surface pressure acting from the first seal member 17 to the upper housing 11). Note that, in order to discharge air remaining in the cavity 65, it is desirable to provide two or more pressure relief holes 67.

[0078] Furthermore, when two or more pressure relief holes 67 are provided in the circumferential direction of the first seal member 17 or the surrounding groove 13e of the first rotating disk 13, it is desirable that the pressure relief holes 67 are provided symmetrically and at equal positions. For example, when two pressure relief holes 67 are provided when the circumferential shape is circular, the two pressure relief holes 67 are provided at positions 180° apart on the circumference. Also, when two pressure relief holes 67 are provided when the circumferential shape is cocoon-shaped, the two pressure relief holes 67 are provided at positions facing each other in the longitudinal direction or at positions facing each other in the lateral direction.

[0079] 30, the first seal member 17 may be formed so that its cross section is formed over the entire surface and does not include the legs 64 or the hollow portion 65. This increases the contact area between the holding portion 61 and the surrounding groove 13e, thereby ensuring sealing between the holding portion 61 and the surrounding groove 13e.

[0080] According to the results of an evaluation conducted by the applicant, as shown in Fig. 25, it was found that the reaction force of the first seal member 17 of the modified example (the value shown by the dashed line in Fig. 25) was reduced by 32% compared to the reaction force when an O-ring was used instead of the first seal member 17 (the value shown by the dashed line in Fig. 25). Note that the reaction force of the first seal member 17 of the modified example and the reaction force when an O-ring is used here refer to the reaction force when the surface pressure of the first seal member 17 of the modified example and the surface pressure of the O-ring are the same.

[0081] Second Embodiment Next, a flow path switching device 101 according to a second embodiment will be described.

[0082] [Outline of Flow Path Switching Device] As shown in FIGS. 31 to 33, the flow path switching device 101 has a housing 111, a valve body portion 112, and a drive portion 113.

[0083] 31 to 33 , the housing 111 is configured by fastening an upper housing 111A and a lower housing 111B together with a plurality of screws 116. The housing 111 includes an inflow channel 120 through which the fluid flows in and an outflow channel 130 through which the fluid flows out. In the present embodiment, the flow path switching device 101 is configured as a six-way valve, for example, and the housing 111 includes three inflow channels 120 and three outflow channels 130.

[0084] The upper housing 111A is provided with three inflow paths 120: a first inflow path 121, a second inflow path 122, and a third inflow path 123. As shown in Fig. 33 , an opening 120a that can communicate with a rotation slot 160 (described later) is provided at one end of the inflow path 120 that faces a rotary disk 140 (described later). Furthermore, the lower housing 111B is provided with three outflow paths 130: a first outflow path 131, a second outflow path 132, and a third outflow path 133.

[0085] The housing 111 is formed of, for example, resin. The upper housing 111A and the lower housing 111B are each an example of a "fixed member" in the present disclosure. The inlet passage 120 (first inlet passage 121, second inlet passage 122, and third inlet passage 123) and the outlet passage 130 (first outlet passage 131, second outlet passage 132, and third outlet passage 133) are each an example of a "communicating passage (provided in the fixed member)" in the present disclosure.

[0086] [Regarding the Valve Disk] The valve disk 112 is provided inside the housing 111. As shown in Figures 32 and 33 , the valve disk 112 includes a fixed disk 150 that does not rotate, a rotating disk 140 that is stacked on the fixed disk 150 and is driven to rotate relative to the upper housing 111A and the fixed disk 150, and a rotating shaft 142 that is provided integrally with the rotating disk 140 at the center of the rotating disk 140.

[0087] The rotating disk 140 (including the rotating shaft 142) and the fixed disk 150 are formed of, for example, resin. The rotating disk 140 is an example of a "driving member" in the present disclosure, and the fixed disk 150 is an example of a "fixed member" in the present disclosure.

[0088] 32 to 34, the rotary disk 140 is disposed between the upper housing 111A and the fixed disk 150. The rotary disk 140 includes a disk portion 141 and a rotary shaft 142.

[0089] The rotating disk 140 (disk portion 141) is formed in a disk shape and includes a plurality of rotation elongated holes 160. These rotation elongated holes 160 penetrate the rotating disk 140 in the plate thickness direction (axial direction), extend along the plate surface direction, and can communicate with the inlet channel 120 and a fixed passage 170 described later. In this embodiment, the rotating disk 140 includes three rotation elongated holes 160. As shown in FIGS. 32 and 34 , the three rotation elongated holes 160 include a first rotation elongated hole 161, a second rotation elongated hole 162, and a third rotation elongated hole 163. The rotation elongated holes 160 (first rotation elongated hole 161, second rotation elongated hole 162, and third rotation elongated hole 163) are an example of a "communication passage (provided in the rotating member)" in the present disclosure.

[0090] [Regarding the Rotating Shaft] The rotating shaft 142 is connected at one axial end to the rotating disk 140 (disk portion 141) and at the other axial end to the driving unit 113. The rotating shaft 142 is formed integrally with the disk portion 141 so that its central axis coincides with the central axis L of the rotating disk 140. The rotating shaft 142 receives a rotational driving force from the driving unit 113 and rotates, causing the rotating disk 140 to rotate around the rotating shaft 142.

[0091] 32, 33, and 35, fixed disk 150 includes a disk portion 151 and a plurality of cylindrical portions 152 formed integrally with disk portion 151. Retaining springs 187 are provided between fixed disk 150 and lower housing 111B to urge fixed disk 150 toward rotating disk 140 and hold it in place. Retaining springs 187 are arranged on the underside of fixed disk 150 so as to encompass each cylindrical portion 152.

[0092] The disk portion 151 is formed in a disk shape and includes fixed passages 170 that penetrate in the axial direction. In this embodiment, the three fixed passages 170 include a first fixed passage 171, a second fixed passage 172, and a third fixed passage 173. The three fixed passages 170 are arranged at equal angular intervals from one another. The fixed passages 170 are an example of a "communicating passage (provided in the fixed member)" in the present disclosure.

[0093] The cylindrical portion 152 is formed to extend in the axial direction from the disk portion 151 so as to surround the fixed passage 170. In this embodiment, three cylindrical portions 152 are formed to correspond to the three fixed passages 170, respectively. The tips of these fixed passages 170 are connected to the outflow passage 130 formed in the lower housing 111B. As shown in Figures 32, 33, and 35, an opening 170a that can communicate with the rotary elongated hole 160 is provided at one end of the fixed passage 170 facing the rotary disk 140.

[0094] [Regarding the Driving Unit] The driving unit 113 includes a motor, a reduction mechanism, and the like (not shown) for applying a rotational driving force to the rotating shaft 142 .

[0095] The flow path switching device 101 configured as described above forms a series of flow paths for the fluid by combining and communicating the inflow paths 120, the rotary slots 160, and the fixed paths 170 (outflow paths 130). The flow path switching device 101 then rotates the rotary disk 140 via the rotary shaft 142 using the drive unit 113, and selectively connects the three rotary slots 160 (161-163), the three inflow paths 120 (121-123), the three fixed paths 170 (171-173), and the three outflow paths 130 (131-133), thereby switching and forming a series of flow paths for the fluid.

[0096] [Regarding the flow path pattern] For example, as shown in Figure 36, in flow path pattern A, three rotary elongated holes 160 (161 to 163) connect the first inlet path 121, the first fixed path 171, and the first outlet path 131, connect the second inlet path 122, the second fixed path 172, and the second outlet path 132, and connect the third inlet path 123, the third fixed path 173, and the third outlet path 133.

[0097] Then, by rotating the rotary disk 140 clockwise by 60° using the drive unit 113, the state of the flow path pattern A shown in FIG. 36 can be switched to the flow path pattern B shown in FIG.

[0098] That is, in flow path pattern B, three rotating elongated holes 160 (161 to 163) connect the first inlet path 121, the third fixed path 173, and the third outlet path 133, connect the second inlet path 122, the first fixed path 171, and the first outlet path 131, and connect the third inlet path 123, the second fixed path 172, and the second outlet path 132.

[0099] Note that the state of flow path pattern B shown in Fig. 37 can be switched to flow path pattern A shown in Fig. 36 by rotating the rotary disk 140 counterclockwise by "60°" using the drive unit 113. Alternatively, the state can be switched to flow path pattern A shown in Fig. 36 by further rotating the rotary disk 140 clockwise by "60°" (in this case, the combination of rotation slots 160 is different).

[0100] 33 , in the flow path switching device 101, seal members 181 for suppressing leakage of fluid in the flow paths are provided between the upper housing 111A and the rotating disk 140 and between the rotating disk 140 and the fixed disk 150. Here, as the seal members 181, an upper seal member 181A is provided between the upper housing 111A and the rotating disk 140, and a lower seal member 181B is provided between the rotating disk 140 and the fixed disk 150.

[0101] As shown in Figures 32 to 34, this seal member 181 is provided on the upper surface 141a and lower surface 141b of the rotating disk 140 (disk portion 141) in a protruding manner so as to surround the periphery of the rotation slot 160. The upper seal member 181A provided on the upper surface 141a of the rotating disk 140 is provided so as to protrude toward the upper housing 111A and contacts the inner surface 111a of the upper housing 11A to seal from the outside the series of flow paths formed between the inflow path 120 and the rotation slot 160 communicating with the inflow path 120. The lower seal member 181B provided on the lower surface 141b of the rotating disk 140 (disk portion 141) is provided so as to contact the fixed disk 150 to seal from the outside the series of flow paths formed between the fixed passage 170 and the rotation slot 160 communicating with the fixed passage 170.

[0102] In this embodiment, the sealing members 181 (181A, 181B) are made of, for example, a rubber material, which is an elastic body. Alternatively, the sealing members 181 may be made of a fluororesin (for example, Teflon (registered trademark)), a rubber with a fluororesin attached, or a material other than fluororesin or rubber.

[0103] 33, a lip seal 188 is provided between upper housing 111A and rotary shaft 142. Another lip seal 189 is provided between each cylindrical portion 152 of fixed disk 150 and lower housing 111B.

[0104] [Details of the Seal Members and Their Surroundings] The cross sections of the upper seal member 181A and the lower seal member 181B of this embodiment are formed in the same shape as the cross sections of the first seal member 17 and the second seal member 18 of the first embodiment (see FIG. 24). The upper seal member 181A and the lower seal member 181B each have the same configuration as the first seal member 17 and the second seal member 18, including a retaining portion 201, a sliding portion 202, a recessed portion 203, a leg portion 204, a hollow portion 205, and a protruding portion 206 (see FIG. 40). The upper seal member 181A (lower seal member 181B) may have a pressure relief hole (not shown) that connects the hollow portion 205 to the outside of the upper seal member 181A (lower seal member 181B). In this case, the pressure relief hole is provided on the opposite side of the upper seal member 181A (lower seal member 181B) from the elongated rotation hole 160.

[0105] First Embodiment This embodiment can be applied to both the upper seal member 181A and the lower seal member 181B, but here, the upper seal member 181A will be described as a representative example.

[0106] In this embodiment, as shown in Fig. 38, two upper seal members 181A are arranged adjacent to each other in order to increase the flow rate by widening the opening area of ​​the rotary slot 160. In this case, as shown in Fig. 39 and Fig. 40, a groove 191 for arranging the upper seal member 181A, which is provided in the disk portion 141 of the rotary disk 140, is provided with a groove protrusion 192, and this groove protrusion 192 is arranged within the hollow portion 205 of the upper seal member 181A.

[0107] 41 , even if the upper seal member 181A moves due to the sliding resistance of the upper seal member 181A when the rotating disk 140 rotates, the movement of the upper seal member 181A is suppressed by the groove protrusion 192. Therefore, stress concentration on the upper seal member 181A caused by the upper seal member 181A moving and deforming is suppressed. Note that the "sliding resistance of the upper seal member 181A" refers to the sliding resistance generated between the upper seal member 181A and the upper housing 11 when the rotating disk 140 rotates.

[0108] Furthermore, because the movement of the upper seal member 181A is suppressed by the groove protrusion 192, when two upper seal members 181A are adjacent to each other, it is possible to prevent the two upper seal members 181A from interfering with each other without providing a partition wall (partition wall) between the two upper seal members 181A. This prevents the device from becoming larger in size due to providing a partition wall between the two upper seal members 181A.

[0109] Second Embodiment This embodiment can be applied to both the upper seal member 181A and the lower seal member 181B, but here, the upper seal member 181A will be described as a representative.

[0110] When the disk portion 141 of the rotary disk 140 rotates in the direction of the arrow shown in Fig. 63 from the state shown in Fig. 62, the sliding resistance of the upper seal member 181A causes the upper seal member 181A to deform toward the right side of the drawing, as shown in Fig. 63. At this time, stress concentration may occur in the upper seal member 181A at the contact portions with the groove protrusions 192 and groove side walls 193, which are shown surrounded by dashed lines in Fig. 63.

[0111] In contrast to this, in this embodiment, as shown in Figure 42, the cross-sectional outline of the groove convex portion 192 is formed in a curved shape such that the curvature gradually increases from the base portion 192a of the groove convex portion 192 to the tip portion 192b, that is, the curvature gradually changes from a large R value to a gradually smaller R value.

[0112] As a result, when the upper seal member 181A is deformed due to the sliding resistance of the upper seal member 181A as the disk portion 141 of the rotating disk 140 rotates in the direction of the arrow shown in Figure 43, the area of ​​contact between the leg portion 204 of the upper seal member 181A and the groove protrusion portion 192 can be expanded as shown by the dashed line in Figure 43, thereby preventing stress from concentrating at the contact portion between the leg portion 204 of the upper seal member 181A and the groove protrusion portion 192.

[0113] Third Embodiment This embodiment relates to preventing the lower seal member 181B from falling off.

[0114] In this embodiment, as shown in Figure 44, the cross-sectional outline of the groove convex portion 192 has a vertical portion 192c near the base portion 192a (slightly below the base portion 192a in Figure 44), and is formed into a curved shape such that the curvature gradually increases from the vertical portion 192c toward the tip portion 192b (the lower side in Figure 44).

[0115] In this way, the surface pressure of the leg portions 204 of the lower seal member 181B can be reliably applied to the vertical portions 192c of the groove convex portions 192, so that the leg portions 204 of the lower seal member 181B can be held by the vertical portions 192c of the groove convex portions 192. As a result, when the disk portion 141 of the rotating disk 140 rotates in the direction of the arrow shown in Figure 45 and the sliding portion 202 of the lower seal member 181B is released into the fixed passage 170 as shown in Figure 46, the lower seal member 181B can be held by the vertical portions 192c of the groove convex portions 192. This prevents the lower seal member 181B from separating from the groove convex portions 192 and falling.

[0116] (Fourth embodiment) This embodiment relates to preventing the lower seal member 181B from falling off.

[0117] In this embodiment, as shown in Fig. 47, a wall protrusion 194 is provided on a groove side wall 193 of the disk portion 141 of the rotary disk 140. In the lower seal member 181B, the seal groove protrusion width δ1, the rubber seal release bottom width δ2, and the seal groove bottom width δ3 shown in Fig. 48 are set to satisfy the following mathematical formula: [Mathematical Formula 1] (Seal groove protrusion width δ1) < (Rubber seal release bottom width δ2) < (Seal groove bottom width δ3)

[0118] This ensures that the surface pressure is maintained between the lower seal member 181B and the wall protrusion 194 even when the sliding portion 202 of the lower seal member 181B is released into the fixed passage 170, thereby preventing the lower seal member 181B from falling into the fixed passage 170.

[0119] If (seal groove bottom width δ3)≦(rubber seal open bottom width δ2), excessive surface pressure will be generated between lower seal member 181B and wall convex portion 194. As a result, when lower seal member 181B is crushed by fixed disk 150 or slides on fixed disk 150, deformation of lower seal member 181B will be difficult to absorb, which may cause sagging of lower seal member 181B.

[0120] Fifth Embodiment This embodiment can be applied to both the upper seal member 181A and the lower seal member 181B, but here, the upper seal member 181A will be described as a representative.

[0121] In this embodiment, as shown in Figures 49 to 51, a convex portion 195 is provided on the groove convex portion 192. This convex portion 195 protrudes toward the groove sidewall 193 as shown in Figures 50 and 51, and has a tapered outer shape as shown in Figure 51. More specifically, the tapered shape refers to a shape in which the width of the convex portion 195 becomes smaller as it approaches the opening side of the groove 191.

[0122] This creates a point where high surface pressure occurs between the leg portion 204 of the upper seal member 181A and the wall convex portion 194 and convex portion 195, as shown by the dashed line in Figure 51, so that the upper seal member 181A is stably held by the wall convex portion 194 and convex portion 195.

[0123] Sixth Embodiment This embodiment can be applied to both the upper seal member 181A and the lower seal member 181B, but the upper seal member 181A will be described here as a representative example.

[0124] In this embodiment, as shown in Figure 52, the side surfaces of the leg portions 204 of the upper seal member 181A are formed vertically (i.e., parallel to the vertical direction), and the side surfaces of the wall convex portions 194 and the convex portions 195 are also formed vertically (i.e., parallel to the vertical direction).

[0125] As a result, as shown by the dashed line in Fig. 52, a location where high surface pressure occurs over a wider range than in the case of Fig. 51 is obtained between the leg portion 204 of the upper seal member 181A and the wall protrusions 194 and 195. Therefore, the upper seal member 181A is stably held by the wall protrusions 194 and 195 while avoiding stress concentration.

[0126] Seventh Embodiment This embodiment can be applied to both the upper seal member 181A and the lower seal member 181B, but here, the upper seal member 181A will be described as a representative.

[0127] As shown in Fig. 64, when the upper seal member 181A is crushed by the upper housing 11A, the first seal portions 211 at both ends of the track-shaped upper seal member 181A in the longitudinal direction (i.e., the rotational direction of the rotary disk 140) try to escape in the long side direction (the direction of the arrows shown in Fig. 64). As a result, as shown in Fig. 65, the upper seal member 181A tilts toward the inner periphery, so that a high surface pressure acts from the groove 191 on the inner leg portion 204 (of the track shape) of the upper seal member 181A, while a low surface pressure acts from the groove 191 on the outer leg portion 204 (of the track shape) of the upper seal member 181A.

[0128] Furthermore, in the convex portions 206, a weak high surface pressure acts on the outer convex portions 206, while a weak low surface pressure acts on the inner convex portions 206. In other words, because the first seal portions 211 at both ends are inclined toward the inner periphery, the compression rate differs between the inner periphery side and the outer periphery side, and the surface pressure acting on the inner convex portions 206 and the outer convex portions 206 differs.

[0129] Furthermore, in the second seal portion 212, which is located at both ends of the shorter side of the upper seal member 181A formed in a track shape and which integrally connects the two first seal portions 211, although not shown, the upper seal member 181A is tilted toward the rotation shaft 142, so that a low surface pressure acts from the groove 191 on the leg portion 204 of the upper seal member 181A on the opposite side of the rotation shaft 142, while a high surface pressure acts from the groove 191 on the leg portion 204 of the upper seal member 181A on the rotation shaft 142 side.

[0130] Furthermore, a weak high surface pressure acts on the convex portion 206 on the side opposite the rotating shaft 142, while a weak low surface pressure acts on the convex portion 206 on the side of the rotating shaft 142. In other words, when the second seal portion 212 is tilted toward the rotating shaft 142, the compression rate differs between the rotating shaft 142 side and the side opposite the rotating shaft 142, and the surface pressure acting on the convex portion 206 on the rotating shaft 142 side and the convex portion 206 on the side opposite the rotating shaft 142 differs.

[0131] In this way, a difference occurs in the surface pressure acting from the groove 191 on the leg portions 204 of the upper seal member 181A between the inner leg portions 204 of the upper seal member 181A and the outer leg portions 204 of the upper seal member 181A.

[0132] Therefore, in this embodiment, the length of the upper seal member 181A (that is, the length of the leg portions 204 and the height of the convex portions 206) is adjusted according to the inclination of each portion of the upper seal member 181A.

[0133] Specifically, as shown in Figures 54 and 56, in the first seal portion 211 (see Figure 53) of the upper seal member 181A, the inner (i.e., inner side of the track shape) leg portion 204 is made shorter by lengths L1d and L3d than the outer (i.e., outer side of the track shape) leg portion 204, and the inner protrusion 206 is made longer (higher) by lengths L1u and L3u than the outer protrusion 206. Furthermore, L1u ≥ L1d and L3u ≥ L3d. This results in a larger compression allowance in the inner portion of the first seal portion 211 of the upper seal member 181A than in the outer portion. Note that "compression allowance" refers to the amount of crushing that can occur.

[0134] This makes it possible to suppress unevenness in the surface pressure of the upper seal member 181A between the inner and outer portions of the first seal portion 211.

[0135] 55 and 57, in the second seal portion 212 (see FIG. 53) of the upper seal member 181A, the leg portion 204 on the rotating shaft 142 side (the outer side in FIG. 55 (i.e., the outer side of the track shape), the inner side in FIG. 57 (i.e., the inner side of the track shape)) is made shorter by lengths L2d and L4d than the leg portion 204 on the opposite side of the rotating shaft 142 (the inner side in FIG. 55, the outer side in FIG. 57). Furthermore, the convex portion 206 on the rotating shaft 142 side is made longer (higher) by lengths L2u and L4u than the convex portion 206 on the opposite side of the rotating shaft 142. Furthermore, L2u≧L2d and L4u≧L4d. This makes it possible to compress the portion of the second seal portion 212 of the upper seal member 181A on the rotating shaft 142 side greater than the portion on the opposite side of the rotating shaft 142. It should be noted that L1u=L3u≧L2u≧L4u, and L1d=L3d≧L2d≧L4d.

[0136] This makes it possible to suppress unevenness in the surface pressure of the upper seal member 181A between the portion of the second seal portion 212 on the rotating shaft 142 side and the portion on the opposite side of the rotating shaft 142.

[0137] Eighth Embodiment This embodiment can be applied to both the upper seal member 181A and the lower seal member 181B, but here, the upper seal member 181A will be described as a representative.

[0138] In this embodiment, the length of the upper seal member 181A (i.e., the height of the convex portion 206) and the depth of the groove 191 are adjusted according to the inclination of each portion of the upper seal member 181A.

[0139] 58 and 60, in the first seal portion 211 (see FIG. 53) of the upper seal member 181A, the inside of the groove 191 (i.e., the inside of the track shape) is made deeper by lengths L1d and L3d than the outside of the groove 191 (i.e., the outside of the track shape), and the inner convex portion 206 is made longer (higher) by lengths L1u and L3u than the outer convex portion 206. This makes it possible to make the compression allowance of the inner portion of the first seal portion 211 of the upper seal member 181A greater than that of the outer portion.

[0140] This makes it possible to suppress unevenness in the surface pressure of the upper seal member 181A between the inner and outer portions of the first seal portion 211.

[0141] 59 and 61, in the second seal portion 212 (see FIG. 53) of the upper seal member 181A, the rotation shaft 142 side of the groove 191 (the outside in FIG. 59 (i.e., the outside of the track shape), the inside in FIG. 61 (i.e., the inside of the track shape)) is made deeper by lengths L2d and L4d than the opposite side of the groove 191 from the rotation shaft 142 (the inside in FIG. 56, the outside in FIG. 57), and the convex portion 206 on the rotation shaft 142 side is made longer (higher) by lengths L2u and L4u than the convex portion 206 on the opposite side of the rotation shaft 142. As a result, in the second seal portion 212 of the upper seal member 181A, the compression allowance is greater in the portion on the rotation shaft 142 side than in the portion opposite the rotation shaft 142.

[0142] This makes it possible to suppress unevenness in the surface pressure of the upper seal member 181A between the portion of the second seal portion 212 on the rotating shaft 142 side and the portion on the opposite side of the rotating shaft 142.

[0143] It should be noted that the above-described embodiments are merely examples and do not limit the present disclosure in any way. It goes without saying that various improvements and modifications are possible within the scope of the gist of the present disclosure.

[0144] The above explanation mainly shows an example in which a sealing member is held by a driving member, but this is not limited to this, and the present disclosure can also be applied to an example in which a sealing member 381 is held by a housing 302, which is a fixed member, rather than by a rotating disk 340, which is a driving member, as shown in Figure 66.

[0145] DESCRIPTION OF SYMBOLS 1 Flow path switching device 2 Housing 3 Valve body portion 4 Drive portion 11 Upper housing 12 Lower housing 13 First rotating disk 13e Surrounding groove 14 Second rotating disk 14e Surrounding groove 15 Rotating shaft 17 First seal member 18 Second seal member 20 Inflow / outflow passage 30 Rotation passage 40 Rotation passage 61 Holding portion 62 Sliding portion 63 Recessed portion 64 Leg portion 65 Cavity portion 66 Convex portion 66a Vertex 67 Pressure relief hole VL Virtual line 101 Flow path switching device 111 Housing 112 Valve body portion 113 Drive portion 120 Inflow passage 130 Outflow passage 140 Rotating disk 150 Fixed disk 160 Rotation elongated hole 170 Fixed passage 181 Seal member 191 Groove 192 Groove protrusion 192a Root portion 192b Tip portion 192c Vertical portion 193 Groove side wall 194 Wall protrusion 195 Protrusion 201 Holding portion 202 Sliding portion 203 Recess 204 Lower leg portion 205 Cavity portion 206 Protrusion 211 First seal portion 212 Second seal portion 302 Housing 340 Rotating disk 381 Seal member

Claims

1. A flow path switching device comprising: a fixed member having a plurality of communication paths; a drive member having a plurality of communication paths; and a flow path formed by combining the communication paths of the drive member and the communication paths of the fixed member, the flow paths being selectively switched by driving the drive member, the flow path switching device comprising: a seal member provided between the fixed member and the drive member around the communication path and preventing fluid from leaking from the communication path, the seal member comprising a holding portion held by the drive member or the fixed member, and a sliding portion which slides against the fixed member or the drive member when the drive member is driven, the sliding portion having a recess formed toward the holding portion, and the cross-sectional outline of the seal member being formed in a mountain shape having a peak on the sliding portion side and expanding laterally on the holding portion side.

2. A flow path switching device according to claim 1, wherein the sealing member is provided with at least two legs formed by bifurcating toward the retaining portion, and a hollow portion formed inside the two legs.

3. A flow path switching device according to claim 2, wherein in a cross section of the sealing member, a convex portion is formed on both sides of the concave portion in the sliding portion, and the hollow portion exists on an imaginary straight line drawn from the apex of the convex portion toward the holding portion.

4. A flow path switching device according to claim 2 or 3, characterized in that it has a pressure relief hole that connects the hollow portion with the outside of the seal member.

5. A flow path switching device according to claim 4, wherein the pressure relief hole is provided in a portion of the sealing member opposite to the communication passage.

6. A flow path switching device according to claim 2 or 3, characterized in that the drive member or the fixed member comprises a groove for holding the holding portion of the sealing member, and a groove protrusion provided in the groove and disposed within the hollow portion.

7. A flow path switching device as claimed in claim 6, characterized in that the cross-sectional outer shape of the groove convex portion is formed in a curved shape with a curvature that gradually increases from the base portion to the tip portion of the groove convex portion.

8. A flow path switching device as claimed in claim 6, wherein the cross-sectional external shape of the groove convex portion has a vertical portion near the base of the groove convex portion, and is formed into a curved shape such that the curvature gradually increases from the vertical portion towards the tip of the groove convex portion.

9. A flow path switching device according to claim 2 or 3, wherein the sealing member is formed in a track shape whose longitudinal direction corresponds to the drive direction of the drive member, and comprises first sealing portions at both ends in the longitudinal direction, and second sealing portions integrally connecting the two first sealing portions, and wherein the compression allowance of the first sealing portions is greater at an inner portion of the track shape than at an outer portion of the track shape.

10. A flow path switching device according to claim 2 or 3, wherein the drive member rotates about a predetermined rotation axis, the seal member is formed in a track shape in which the drive direction of the drive member is the longitudinal direction, and comprises first seal portions at both ends in the longitudinal direction and second seal portions integrally connecting the two first seal portions, and the second seal portion has a larger compression allowance at a portion on the side of the rotation axis than at a portion on the opposite side of the rotation axis.

11. A flow path switching device according to any one of claims 1 to 3, characterized in that the flow path switching device is used in a cooling system for an electric vehicle.

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