Flow path switching device

Abstract

To provide a flow path switching device capable of securing the sealability with a seal member.SOLUTION: In one embodiment of this invention, a flow path switching device 1 for communicating an inflow path 20 of a housing 11, a rotary disc communication path 60 of a rotary disc 40, and a fixed disc communication path 70 of a fixed disc 50 with one another to form a flow path where fluid flows includes seal members 81A, 81B provided on the rotary disc 40 for contacting the housing 11 or the fixed disc 50 in the state that pressing force works thereon to seal a space between the inflow path 20 or the fixed disc communication path 70 and the rotary disc communication path 60 communicated with the inflow path 20 or the fixed disc communication path 70, the rotary disc 40 having higher rigidity than the fixed disc 50.SELECTED DRAWING: Figure 12

Description

Technical Field

[0001] The present disclosure relates to a flow path switching device that switches a flow path pattern through which a fluid flows.

Background Art

[0002] Patent Document 1 discloses a flow path switching valve in which a rotor seal provided on a rotor slides on a stator when the rotor rotates.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] [[ID=3%]]In the flow path switching valve disclosed in Patent Document 1, when the rotor seal crosses the stator flow path, a non-contact portion that is released into the stator flow path and does not contact the stator and a contact portion that contacts the stator are generated in the rotor seal. Therefore, there is a possibility that stress is locally generated at the boundary portion between the non-contact portion and the contact portion in the rotor seal. Therefore, there is a possibility that wear and cracks may occur in the rotor seal, and the sealing performance by the rotor seal may deteriorate.

[0005] Therefore, the present disclosure has been made to solve the above problems, and an object thereof is to provide a flow path switching device capable of ensuring the sealing performance by a seal member.

Means for Solving the Problems

[0006] One embodiment of the present disclosure made to solve the above problems is a flow path switching device having at least one fixed member and a drive member, wherein the fixed member is provided with a port and the drive member is provided with a communication passage, and the port of the fixed member and the communication passage of the drive member are connected to form a flow path through which fluid flows. ,before Provided on the drive member , press The device has a sealing member that contacts the fixed member under pressure and seals the space between the port of the fixed member and the communication passage of the drive member that communicates with the port of the fixed member, and the drive member is more rigid than at least one of the fixed members. The fixing member comprises a first fixing member and a second fixing member, the drive member is positioned between the first fixing member and the second fixing member, the sealing member comprises a first sealing member provided between the first fixing member and the drive member, and a second sealing member provided between the drive member and the second fixing member, the drive member is held between the first fixing member and the second fixing member with the pressing force acting via the second fixing member and the second sealing member, and the port of the second fixing member is positioned so that the second sealing member does not cross when the drive member is driven to switch the flow path pattern. It is characterized by the following.

[0007] In this embodiment, since the drive member is highly rigid and resistant to deformation, the posture of the sealing member provided on the drive member is maintained. Therefore, localized stress generation in the sealing member can be suppressed, thereby suppressing wear and cracking of the sealing member. Consequently, the sealing performance of the sealing member can be ensured. Furthermore, when the drive member is driven to switch the flow path pattern, the second seal member does not cross the port of the second fixed member. Therefore, deformation of the second fixed member can be suppressed. Consequently, the second fixed member can be made thinner (with reduced rigidity). In addition, localized stress generation in the second seal member due to deformation of the second fixed member can be suppressed, thus preventing wear and cracking of the second seal member. Thus, the sealing performance of the second seal member can be ensured.

[0010] In the above embodiment, it is preferable that a radius (R) or a taper is formed on the edge of the opening on the drive member side of the port of the fixed member, and that the size of the radius or the taper is larger at the first end, which is the end of the edge of the opening in the driving direction of the drive member, than at the second end, which is the end of the edge of the opening in a direction perpendicular or substantially perpendicular to the driving direction of the drive member, and gradually decreases from the first end toward the second end.

[0011] According to this embodiment, when the drive member is driven to switch the flow path pattern, when the sealing member crosses the port of the stationary member, the non-contact portion of the sealing member that is open within the port of the stationary member and not in contact with the stationary member moves outside the port and comes into contact with the stationary member, making it less likely to catch on the edge of the port of the stationary member. Therefore, wear and cracking of the sealing member can be suppressed. Thus, the sealing performance of the sealing member can be ensured.

[0012] In the above embodiment, when the drive member is driven to switch the flow path pattern, it is preferable to set the drive speed of the drive member to a first low speed, which is slower than the normal speed, while the seal member is crossing the port of the fixed member.

[0013] According to this embodiment, as the sealing member crosses the port of the fixed member, the location where localized stress occurs in the sealing member can be gradually moved. Therefore, wear and cracking of the sealing member can be suppressed. Thus, the sealing performance of the sealing member can be ensured.

[0014] In the above embodiment, when the drive member is driven to switch the flow path pattern, it is preferable to set the drive speed of the drive member to a second low speed that is slower than the first low speed when the seal member transitions from crossing the port of the fixed member to not crossing it.

[0015] According to this embodiment, when the sealing member transitions from a state where it crosses the port of the fixed member to a state where it does not cross it, that is, when the non-contact portion of the sealing member that is released into the port of the fixed member and is not in contact with the fixed member moves from inside the port of the fixed member to outside the port and rides up onto the contact surface with the fixed member, the location where local stress is generated in the sealing member is gradually moved. As a result, wear and cracking of the sealing member can be suppressed more effectively. Consequently, the sealing performance of the sealing member can be ensured more effectively.

[0016] In the above embodiment, a radius (R) or taper is formed on the edge of the opening on the drive member side of the port of the fixed member, and it is preferable that the size of the R or the taper is larger at the first end, which is the end of the edge of the opening in the driving direction of the drive member, than at the second end, which is the end of the edge of the opening in a direction perpendicular to the driving direction of the drive member, and that the radius of the inner circumference of the edge of the opening and the radius of the outer circumference of the edge of the opening are equal or approximately equal at the first end and the second end, respectively.

[0017] In this embodiment, at the edge of the opening on the drive member side of the port of the fixed member, the size of R or taper is made larger at the first end than at the second end, while the inner and outer radii of the edge of the opening are equal (or approximately equal) at the first and second ends, respectively.

[0018] As a result, when the drive member drives relative to the stationary member and the seal member passes through the port of the stationary member, the portion of the seal member that is temporarily released into the port of the stationary member rides up onto the first end of the edge of the opening, effectively pushing the seal member upwards. Therefore, the seal member can ride up smoothly onto the first end of the edge of the opening. Consequently, the seal member can pass smoothly through the port of the stationary member.

[0019] In the above embodiment, when the radius of the inner circumference of the edge of the opening is r1 and the radius of the outer circumference of the edge of the opening is r2, it is preferable that the size of R at the first end is greater than (r2-r1).

[0020] According to this embodiment, the size of R is reliably increased at the first end of the edge of the opening. Therefore, when the portion of the fixed member that is temporarily released into the port by the sealing member rides up to the first end of the edge of the opening, the sealing member can be pushed up more reliably and effectively.

[0021] In the above embodiment, it is preferable that, regarding the shape of the edge of the opening on the drive member side of the port of the fixed member, the first opening curvature, which is the curvature at the first end, which is the end of the edge of the opening in the driving direction of the drive member, is smaller than the second opening curvature, which is the curvature at the second end, which is the end of the edge of the opening in a direction perpendicular to the driving direction of the drive member.

[0022] In this embodiment, the curvature at the first end (i.e., the first opening curvature) of the edge of the opening is reduced.

[0023] Thus, when the driving member drives relative to the fixing member and the sealing member passes through the port of the fixing member, just before a portion of the sealing member that is once released into the port of the fixing member rides over the first end portion of the edge of the opening, the compressive stress acting on the sealing member is suppressed. Therefore, the amount by which the sealing member protrudes into the port of the fixing member is reduced. Accordingly, the sealing member can smoothly ride over the first end portion of the edge of the opening.

[0024] In the above aspect, with respect to the shape of the edge of the opening on the driving member side in the port of the fixing member, it is preferable that an edge straight portion formed linearly so as to be orthogonal to the driving direction is formed at the first end portion which is the end portion in the driving direction of the driving member on the edge of the opening.

[0025] According to this aspect, with respect to the shape of the edge of the opening, the first end portion is formed linearly so as to be orthogonal to the driving direction of the driving member.

[0026] Thus, when the driving member drives relative to the fixing member and the sealing member passes through the port of the fixing member, just before a portion of the sealing member that is once released into the port of the fixing member rides over the first end portion of the edge of the opening, the compressive stress acting on the sealing member is suppressed. Therefore, the amount by which the sealing member protrudes into the port of the fixing member is reduced. Accordingly, the sealing member can smoothly ride over the first end portion of the edge of the opening.

[0027] In the above aspect, with respect to the shape of the sealing member, it is preferable that a sealing member straight portion formed linearly so as to be orthogonal to the driving direction, or a sealing member substantially straight portion formed substantially linearly, is formed at the end portion in the driving direction of the driving member.

[0028] In this embodiment, the shape of the sealing member is such that the end portion in the driving direction of the driving member, that is, the portion that is temporarily released into the port of the fixed member and rides up on the first end of the edge of the opening when the sealing member passes through the port of the fixed member as the driving member is driven relative to the fixed member, is formed in a straight or substantially straight shape so as to be perpendicular to the driving direction of the driving member.

[0029] As a result, the compressive stress acting on the sealing member is suppressed just before the portion of the fixing member that is temporarily released into the port by the sealing member rides up onto the first end of the edge of the opening. Therefore, the amount of the sealing member protruding into the port of the fixing member is reduced. Consequently, the sealing member can ride up smoothly onto the first end of the edge of the opening. 。 [Effects of the Invention]

[0030] According to the flow path switching device of this disclosure, sealing performance can be ensured by the sealing member. [Brief explanation of the drawing]

[0031] [Figure 1] This is an external perspective view of the flow path switching device (in the case of a hexagonal valve) according to the first and second embodiments. [Figure 2] This is an exploded perspective view of the flow path switching device of the first and second embodiments (the drive unit and control unit are omitted from the illustration). [Figure 3] This is a cross-sectional view of the flow path switching device according to the first and second embodiments (the drive unit and control unit are omitted from the illustration). [Figure 4] This is a top view of the rotating disk. [Figure 5] This is a top view of the fixed disk. [Figure 6] This diagram schematically shows the first flow path pattern, and is an image of what it looks like when viewed from above the flow path switching device. [Figure 7] This diagram schematically shows the second flow path pattern, and is an image of what it looks like when viewed from above the flow path switching device. [Figure 8]This diagram shows the positional relationship between the first sealing member and the inflow channel when switching the flow path pattern. [Figure 9] This is an enlarged view of the third inflow channel and its surroundings in Figure 8(A). [Figure 10] This is a cross-sectional view of the housing, rotating disk, and stationary disk in Figure 8(A). [Figure 11] This is an enlarged view of the third inflow channel and its surroundings in Figure 8(B). [Figure 12] Figure 8(B) is a cross-sectional view of the housing, rotating disk, and stationary disk. [Figure 13] This diagram shows the positional relationship between the second sealing member and the fixed disk communication passage when switching the flow path pattern. [Figure 14] This is a cross-sectional view AA in Figure 11. [Figure 15] Figure 11 is a cross-sectional view of BB. [Figure 16] This is a flowchart illustrating the first control method related to the rotational speed of a rotating member. [Figure 17] This figure shows the trajectory of the movement of the first sealing member when the control shown in Figure 16 is performed. [Figure 18] This is a flowchart illustrating the second control method related to the rotational speed of the rotating member. [Figure 19] This figure shows the trajectory of the movement of the first sealing member when the control shown in Figure 18 is performed. [Figure 20] This is an overall schematic diagram of a sliding flow path switching device (a diagram showing the first flow path pattern). [Figure 21] Figure 20 is a cross-sectional view of CC. [Figure 22] This is an overall schematic diagram of a sliding flow path switching device (a diagram showing the second flow path pattern). [Figure 23] Figure 22 is a cross-sectional view of the DD. [Figure 24] This diagram shows the case where the second sealing member crosses the fixed disc connecting passage. [Figure 25] This diagram shows the case where the second sealing member crosses the fixed disc connecting passage. [Figure 26] This diagram shows the first sealing member catching on the edge of the opening of the inflow channel. [Figure 27] In the second embodiment, this is a view of the housing from the rotating disk side, showing the edge of the opening of the inflow channel and the first sealing member. [Figure 28] (A) is a view along the EE arrow in Figure 27, (B) is a view along the FF arrow in Figure 27, and (C) is a diagram showing the position of the inner circumference of the edge of the opening of the inflow channel. [Figure 29] This figure shows how, in the second embodiment, the portion that has been temporarily released into the inflow channel by the first sealing member rides up onto the first end of the edge of the opening of the inflow channel. [Figure 30] This is a diagram showing the first modified example. [Figure 31] This figure shows a second modified example. [Figure 32] This figure shows another example of the second variation. [Figure 33] This figure shows a third modified example. [Figure 34] This figure shows the first sealing member moving from the first end, which is on the opposite side of the rotation direction of the rotating disk at the edge of the opening of the inflow channel, toward the second end. [Figure 35] This figure shows that tensile stress is generated in the first sealing member when the conditions are as shown in Figure 34. [Figure 36] This figure shows the movement of the first sealing member from the second end at the edge of the opening of the inflow channel toward the first end on the rotational side of the rotating disk. [Figure 37] This figure shows that compressive stress is generated in the first sealing member when the conditions are as shown in Figure 36. [Figure 38] This diagram shows that the portion that was temporarily released into the inflow channel by the first sealing member is pushed up from the inflow channel. [Figure 39] In the comparative example, this figure shows how the portion that was temporarily released into the inflow channel by the first sealing member rides up onto the first end of the edge of the opening of the inflow channel. [Figure 40]This figure shows how, in the first embodiment, the portion that has been temporarily released into the inflow channel by the first sealing member rides up onto the first end of the edge of the opening of the inflow channel. [Figure 41] In the first embodiment, this is a view of the housing from the rotating disk side, showing the edge of the opening of the inflow channel and the first sealing member. [Modes for carrying out the invention]

[0032] An example of an embodiment of this disclosure, a flow path switching device, will be described.

[0033] [First Embodiment] <Overall Overview of the Flow Channel Switching Device> First, an overview of the flow path switching device 1 of this embodiment will be described.

[0034] As shown in Figures 1 to 3, the flow path switching device 1 includes a housing 11, a valve body 12, a drive unit 13, and a control unit 14.

[0035] The housing 11 includes an inflow channel 20 through which fluid flows in and an outflow channel 30 through which fluid flows out. Here, the flow path switching device 1 is, for example, a hexagonal valve, and the housing 11 includes three inflow channels 20 and three outflow channels 30. The three inflow channels 20 are a first inflow channel 21, a second inflow channel 22, and a third inflow channel 23. The three outflow channels 30 are a first outflow channel 31, a second outflow channel 32, and a third outflow channel 33.

[0036] The housing 11 is formed of, for example, resin. The housing 11 is an example of the “fixing member” or “first fixing member” of this disclosure, and the inflow passage 20 (i.e., the first inflow passage 21, the second inflow passage 22, and the third inflow passage 23) is an example of the “port” of this disclosure.

[0037] The valve body 12 is located inside the housing 11. As shown in Figures 2 and 3, the valve body 12 comprises a rotating plate-shaped rotating disk 40 and a plate-shaped fixed disk 50. The rotating disk 40 and the fixed disk 50 are stacked in the direction of the central axis L of the disc portion 41 of the rotating disk 40 and the disc portion 51 of the fixed disk 50 (hereinafter simply referred to as the "axial direction").

[0038] The rotating disk 40 and the stationary disk 50 are formed of, for example, resin. The rotating disk 40 is an example of the "driving member" of this disclosure, and the stationary disk 50 is an example of the "fixing member" or "second fixing member" of this disclosure.

[0039] As shown in Figures 2 to 4, the rotating disk 40 is positioned between the housing 11 and the fixed disk 50, and is held between the housing 11 and the fixed disk 50, with stress acting on it due to the pressing force of the disk holding spring 82 (described later) via the fixed disk 50 and the second sealing member 81B (described later). The rotating disk 40 comprises a disc portion 41 and a rotating shaft portion 42.

[0040] The disc portion 41 is formed in a disc shape and is equipped with a rotating disk communication passage 60. This rotating disk communication passage 60 penetrates the disc portion 41 in the axial direction and can communicate with the inflow passage 20 and the fixed disk communication passage 70, which will be described later. Here, the disc portion 41 is equipped with three rotating disk communication passages 60. As shown in Figures 2 and 4, the three rotating disk communication passages 60 are a first rotating disk communication passage 61, a second rotating disk communication passage 62, and a third rotating disk communication passage 63. Note that the rotating disk communication passages 60 (i.e., the first rotating disk communication passage 61, the second rotating disk communication passage 62, and the third rotating disk communication passage 63) are examples of "communication passages" in this disclosure.

[0041] The rotating shaft portion 42 is connected to the disc portion 41 at one end and to the drive unit 13 at the other end, in the direction of its central axis. The rotating shaft portion 42 is positioned in the center of the disc portion 41 such that its central axis coincides with the central axis L of the disc portion 41. By obtaining rotational power from the drive unit 13, the rotating shaft portion 42 rotates around its central axis, causing the disc portion 41 connected to the rotating shaft portion 42 to rotate around its central axis L. In this way, the rotating disk 40 rotates around its central axis L by obtaining rotational power from the drive unit 13.

[0042] As shown in Figures 2, 3, and 5, the fixed disk 50 comprises a disc portion 51 and a cylindrical portion 52.

[0043] The disc portion 51 is formed in a disc shape and is provided with a fixed disk access passage 70 that penetrates it in the axial direction. Here, the disc portion 51 is provided with three fixed disk access passages 70. As shown in Figures 2 and 5, the three fixed disk access passages 70 are a first fixed disk access passage 71, a second fixed disk access passage 72, and a third fixed disk access passage 73. Note that the fixed disk access passages 70 (i.e., the first fixed disk access passage 71, the second fixed disk access passage 72, and the third fixed disk access passage 73) are examples of "ports" in this disclosure.

[0044] The cylindrical portion 52 is connected to the disc portion 51 and is formed to extend axially from the disc portion 51 so as to surround the fixed disk connecting passage 70. In this case, three cylindrical portions 52 are formed, one for each of the three fixed disk connecting passages 70.

[0045] The drive unit 13 includes a motor (not shown) for supplying rotational power to the rotating shaft portion 42 of the rotating disk 40.

[0046] The control unit 14, for example, includes a CPU and memory such as ROM and RAM, and controls the flow path switching device 1 according to a program pre-stored in the memory.

[0047] The flow path switching device 1, configured as described above, forms a fluid flow path by connecting the inflow flow path 20, the rotating disk connecting passage 60, and the fixed disk connecting passage 70 (outflow flow path 30). The flow path switching device 1 then rotates the rotating disk 40 using the drive unit 13 and switches the combination of the connected inflow flow path 20 and fixed disk connecting passage 70 and rotating disk connecting passage 60, thereby switching the flow path pattern (hereinafter referred to as the "flow path pattern").

[0048] For example, as shown in Figure 6, as a first flow path pattern, three rotating disk connecting passages 60 (i.e., a first rotating disk connecting passage 61, a second rotating disk connecting passage 62, and a third rotating disk connecting passage 63) connect the first inflow passage 21 to the third fixed disk connecting passage 73 (third outflow passage 33), the second inflow passage 22 to the first fixed disk connecting passage 71 (first outflow passage 31), and the third inflow passage 23 to the second fixed disk connecting passage 72 (second outflow passage 32).

[0049] Then, from the state of the first flow path pattern shown in Figure 6, the drive unit 13 can rotate the rotating disk 40 counterclockwise to switch to the second flow path pattern shown in Figure 7.

[0050] In other words, as shown in Figure 7, as a second flow path pattern, the first inflow path 21 is connected to the first fixed disk connecting path 71 (first outflow path 31) by three rotating disk connecting passages 60, the second inflow path 22 is connected to the second fixed disk connecting passage 72 (second outflow path 32), and the third inflow path 23 is connected to the third fixed disk connecting passage 73 (third outflow path 33).

[0051] Furthermore, from the state of the second flow path pattern shown in Figure 7, the drive unit 13 can rotate the rotating disk 40 clockwise to switch to the first flow path pattern shown in Figure 6. In addition, the flow path switching device 1 is not limited to a six-way valve, but can also be a three-way valve, a four-way valve, or other multi-way valve.

[0052] Furthermore, in this embodiment, elastic members are provided in the axial direction between the housing 11 and the rotating disk 40, between the rotating disk 40 and the fixed disk 50, and between the fixed disk 50 and the housing 11.

[0053] Specifically, as shown in Figure 3, a first sealing member 81A and a second sealing member 81B are provided as elastic members between the housing 11 and the rotating disk 40, and between the rotating disk 40 and the fixed disk 50, respectively.

[0054] As shown in Figures 2 to 4, the first sealing member 81A and the second sealing member 81B are provided circumferentially around the rotating disk communication passage 60, which is formed in an elongated hole shape on the upper surface 41a and lower surface 41b of the disc portion 41 of the rotating disk 40. The first sealing member 81A contacts the housing 11 and seals the flow path formed between the inflow passage 20 and the rotating disk communication passage 60 that communicates with the inflow passage 20 from the outside. The second sealing member 81B contacts the fixed disk 50 and seals the flow path formed between the fixed disk communication passage 70 and the rotating disk communication passage 60 that communicates with the fixed disk communication passage 70 from the outside.

[0055] The first sealing member 81A and the second sealing member 81B are formed of, for example, fluororesin (e.g., Teflon®). Alternatively, the first sealing member 81A and the second sealing member 81B may be formed of rubber with fluororesin attached. Furthermore, the first sealing member 81A and the second sealing member 81B may be formed of materials other than fluororesin or rubber.

[0056] Furthermore, a disc-holding spring 82 is provided as an elastic member between the disc portion 51 of the fixed disc 50 and the housing 11. The stress caused by the pressing force of this disc-holding spring 82 acts on the disc portion 51 of the fixed disc 50. Three such disc-holding springs 82 are provided, one for each of the three cylindrical portions 52 of the fixed disc 50. The three disc-holding springs 82 are provided at equal intervals from each other. Alternatively, the three disc-holding springs 82 may be positioned between each of the three cylindrical portions 52. In addition, four or more disc-holding springs 82 may be provided.

[0057] Furthermore, a lip seal 83 is provided between the cylindrical portion 52 of the fixed disk 50 and the housing 11 to ensure the sealing performance of the fixed disk communication passage 70.

[0058] <Regarding ensuring sealing performance with sealing materials> (Regarding the rigidity of the rotating disk) When the rotating disk 40 is rotated to switch the flow path pattern, the first sealing member 81A crosses the inflow flow path 20, creating a non-contact portion within the inflow flow path 20 that does not contact the housing 11, and a contact portion that contacts the housing 11. At this point, the first sealing member 81A is subjected to stress due to the pressing force of the disk holding spring 82. Consequently, there is a risk of localized stress occurring at the boundary between the non-contact portion and the contact portion of the first sealing member 81A.

[0059] Specifically, when switching between the flow path patterns A and B, the positional relationship between the first sealing member 81A and the inflow flow path 20 (for example, the second inflow flow path 22 and the third inflow flow path 23) becomes as shown in Figure 8. Note that pattern A is the first flow path pattern shown in Figure 6, and pattern B is the second flow path pattern shown in Figure 7.

[0060] First, in state (A) of Figure 8, as shown in Figures 9 and 10, the first seal member 81A does not cross the inflow channel 20 (for example, the third inflow channel 23). Therefore, the first seal member 81A is in contact with the housing 11 overall. Consequently, the first seal member 81A is subjected to stress (see Figure 10) due to the pressing force of the disk holding spring 82 via the fixed disk 50, the second seal member 81B, and the rotating disk 40.

[0061] However, in the state shown in Figure 8(B), the first sealing member 81A crosses the inflow channel 20 (for example, the third inflow channel 23), as shown in Figures 11 and 12. Therefore, as shown in Figure 11, the first sealing member 81A has a non-contact portion that is open into the inflow channel 20 and does not contact the housing 11, and a contact portion that is in contact with the housing 11.

[0062] As shown in Figure 12, the first sealing member 81A is subjected to stress due to the pressing force of the disk holding spring 82 via the fixed disk 50, the second sealing member 81B, and the rotating disk 40. As a result, a displacement of the rotating disk 40 occurs due to stress release at the non-contact portion (of the first sealing member 81A) as indicated by the arrow (hereinafter referred to as "displacement due to stress release").

[0063] Furthermore, if the displacement due to this stress release becomes large, it becomes difficult to maintain the posture of the first sealing member 81A provided on the rotating disk 40, and there is a risk that a large localized stress will occur at the boundary between the non-contact portion and the contact portion of the first sealing member 81A. This may lead to wear and cracking of the first sealing member 81A, and a decrease in the sealing performance of the first sealing member 81A.

[0064] Therefore, in this embodiment, the rotational disk 40 is made highly rigid and less prone to bending, thereby reducing displacement due to stress release. Specifically, the thickness of the rotational disk 40 is made greater than that of the fixed disk 50, making the rotational disk 40 more rigid than the fixed disk 50.

[0065] In this way, by making the rotating disk 40 highly rigid and less prone to deformation, the displacement due to stress release in the rotating disk 40 can be reduced, and the posture of the first sealing member 81A provided on the rotating disk 40 is maintained. Therefore, it is possible to suppress the generation of large localized stresses at the boundary between the non-contact portion and the contact portion of the first sealing member 81A. Consequently, wear and cracking of the first sealing member 81A can be suppressed, and the sealing performance of the first sealing member 81A can be ensured.

[0066] (Regarding the second sealing member) When the rotating disk 40 is rotated to switch the flow path pattern, the second sealing member 81B crosses the fixed disk communication passage 70 (for example, the second fixed disk communication passage 72), as shown in Figure 24, the second sealing member 81B has a non-contact portion that is open into the fixed disk communication passage 70 and does not contact the fixed disk 50, and a contact portion that is in contact with the fixed disk 50.

[0067] As shown in Figure 25, stress is acting on the fixed disk 50 due to the pressing force of the disk holding spring 82, causing displacement due to stress release as indicated by the arrows in the fixed disk 50. Here, since the fixed disk 50 has a small plate thickness and low rigidity, the displacement due to stress release becomes large, which may cause a large localized stress at the boundary between the non-contact portion and the contact portion of the second seal member 81B. If this occurs, wear and cracking of the second seal member 81B may occur easily, and the sealing performance of the second seal member 81B may decrease.

[0068] Furthermore, since the stress caused by the pressing force of the disk holding spring 82 acting on the rotating disk 40 is also reduced, the sealing performance of the first sealing member 81A provided on the rotating disk 40 may also decrease.

[0069] Therefore, in this embodiment, when the rotating disk 40 is rotated to switch the flow path pattern between pattern A and pattern B, the second sealing member 81B is prevented from crossing the fixed disk communication passage 70 of the fixed disk 50 (for example, the second fixed disk communication passage 72), as shown in Figure 13. Specifically, the fixed disk communication passage 70 of the fixed disk 50 is positioned so that the second sealing member 81B does not cross it when the rotating disk 40 rotates to switch the flow path pattern between pattern A and pattern B.

[0070] As a result, when the rotating disk 40 is rotated to switch the flow path pattern between pattern A and pattern B, the second sealing member 81B does not cross the fixed disk communication passage 70 of the fixed disk 50. Therefore, deformation of the fixed disk 50 can be suppressed. Consequently, the fixed disk 50 can be made thinner (with reduced rigidity). In addition, deformation of the low-rigidity fixed disk 50 can suppress the generation of large localized stresses at the boundary between the non-contact and contact portions of the second sealing member 81B, thereby suppressing wear and cracking of the second sealing member 81B. Thus, the sealing performance of the second sealing member 81B can be ensured.

[0071] (Regarding the edge of the opening of the inflow channel) When the first sealing member 81A crosses the inflow channel 20, the non-contact portion of the first sealing member 81A eventually moves from inside the inflow channel 20 to outside the inflow channel 20 and comes into contact with the housing 11. At this time, as shown in Figure 26, the edge 20a of the opening of the inflow channel 20 in the housing 11 becomes a step, and the non-contact portion of the first sealing member 81A may get caught on this step, potentially causing wear or cracking of the first sealing member 81A.

[0072] Therefore, the edge 20a of the opening on the rotating disk 40 side in the inflow channel 20 of the housing 11 may have a curved shape (R).

[0073] However, if a constant radius (R) is formed around the entire circumference of the edge 20a, the diameter of the edge 20a will increase around its entire circumference, which may increase the size of the housing 11. Therefore, the size of the radius (R) is varied depending on the circumferential position of the edge 20a.

[0074] Specifically, as shown in Figures 14 and 15(a), the size of R is larger at the first end 20b (see Figure 11), which is the end of the rotating disk 40 in the direction of rotation at the edge 20a of the opening, than at the second end 20c (see Figure 11), which is the end in a direction perpendicular (or approximately perpendicular) to the direction of rotation of the rotating disk 40. Furthermore, the size of R gradually decreases in the circumferential direction of the edge 20a from the first end 20b to the second end 20c. For example, if the size of R at the first end 20b is 2 mm, the size of R at the second end 20c is 0.5 mm. Also, "direction of rotation" is an example of "direction of driving" in this disclosure.

[0075] As a result, when the first sealing member 81A crosses the inflow channel 20 of the housing 11, the non-contact portion of the first sealing member 81A moves outside the inflow channel 20 and comes into contact with the housing 11, making it less likely to get caught on the edge 20a of the opening of the inflow channel 20. Therefore, wear and cracking of the first sealing member 81A can be suppressed. Thus, the sealing performance of the first sealing member 81A can be ensured.

[0076] Furthermore, since the size of R is varied depending on the circumferential position of the edge 20a, it is possible to suppress an increase in the size of the housing 11. For example, since R is made smaller at the position of the second end 20c, the size of the housing 11 can be made smaller than in the case of Figure 15(b) (i.e., when R is made larger), as shown in Figure 15(a).

[0077] Furthermore, instead of a radius (R), a taper may be formed on the edge 20a of the opening on the rotating disk 40 side of the inflow channel 20. Also, as shown in Figures 24 and 25, if the second sealing member 81B crosses the fixed disk communication passage 70, a radius (R) or a taper may be formed on the edge of the opening on the rotating disk 40 side of the fixed disk communication passage 70.

[0078] (Regarding the first control of the rotational speed of the rotating disk) As a first control of the rotational speed of the rotating disk 40, when the rotating disk 40 is rotated to switch the flow path pattern, the rotational speed of the rotating disk 40 may be controlled to slow down when the first seal member 81A crosses the inflow flow path 20 of the housing 11. By doing so, wear and cracks in the first seal member 81A can be suppressed by gradually moving the boundary between the non-contact and contact portions where stress is concentrated.

[0079] Specifically, the control unit 14 performs the control shown in Figure 16 as a first control related to the rotation speed of the rotating disk 40.

[0080] As shown in Figure 16, the control unit 14 receives the switching valve position angle tdeg (step S1) and determines whether or not there is a request to switch the flow path pattern (step S2).

[0081] Here, "switching valve position angle tdeg" indicates the position of the first seal member 81A in the rotational direction of the rotating disk 40. More specifically, as shown in Figure 17, "switching valve position angle tdeg" is the angle formed by the line connecting the position of the rearmost part of the first seal member 81A when the rotating disk 40 rotates counterclockwise (i.e., the position of the frontmost part of the first seal member 81A when the rotating disk 40 rotates clockwise) and the position of the rotation center O of the rotating disk 40, with the line α of angle 0. The control unit 14 obtains the detected value of the rotation angle of the rotating disk 40 from an angle sensor (not shown).

[0082] Then, if there is a request to switch the flow path pattern (step S2: YES), the control unit 14 determines whether the switching flag (X switching) is "0" or not (step S3).

[0083] Then, if the switching flag is "0" (step S3: YES), the control unit 14 determines whether the current flow path pattern is pattern A or not, that is, whether the current flow path pattern is pattern A or not, in order to start switching the flow path pattern (step S4). Here, pattern A is the first flow path pattern shown in Figure 6 above.

[0084] Then, if the current state is pattern A (step S4: YES), the control unit 14 sets the switching flag and the switching A flag (X switching A) to "1" (step S5) and performs a low-speed counterclockwise drive on the rotating disk 40 (step S6) in order to switch the flow path pattern from pattern A to pattern B by rotating the rotating disk 40 counterclockwise. In other words, the control unit 14 rotates the rotating disk 40 counterclockwise at a low speed. Here, "low speed" means a speed lower than the normal speed when switching the flow path pattern (for example, half the normal speed), and is an example of the "first low speed" in this disclosure.

[0085] Next, the control unit 14 determines whether the switching valve position angle tdeg is less than angle A (see Figure 17) (step S7).

[0086] Then, if the switching valve position angle tdeg is less than angle A (step S7: YES), the control unit 14 stops the switching drive, that is, stops the rotation of the rotating disk 40, and sets the switching flag to "0" (step S8).

[0087] On the other hand, if the switching valve position angle tdeg is greater than or equal to angle A (step S7: NO), the control unit 14 continues to rotate the rotating disk 40 counterclockwise at a low speed.

[0088] Furthermore, in step S4, if the current flow path pattern is not pattern A (step S4: NO), that is, if the current flow path pattern is pattern B, the control unit 14 rotates the rotating disk 40 clockwise to switch the flow path pattern from pattern B to pattern A, by setting the switching flag to "1" and the switching A flag to "0" (step S9). Here, pattern B is the second flow path pattern shown in Figure 7 above.

[0089] Next, the control unit 14 performs a slow clockwise drive on the rotating disk 40 (step S10). That is, the control unit 14 rotates the rotating disk 40 clockwise at a slow speed.

[0090] Next, the control unit 14 determines whether the switching valve position angle tdeg is greater than or equal to angle H (see Figure 17) (step S11).

[0091] Then, if the switching valve position angle tdeg is greater than or equal to angle H (step S11: YES), the control unit 14 stops the switching drive and sets the switching flag to "0" (step S8).

[0092] On the other hand, if the switching valve position angle tdeg is less than angle H (step S11: NO), the control unit 14 continues to rotate the rotating disk 40 clockwise at a low speed.

[0093] Furthermore, in step S3, if the switching flag is "1" (step S3: NO), the flow path pattern has been switched, so the control unit 14 determines whether or not the switching A flag is "1" (step S12).

[0094] Then, if the switching A flag is "1" (step S12: YES), the rotating disk 40 is rotated counterclockwise to switch the flow path pattern from pattern A to pattern B, so the control unit 14 determines whether the switching valve position angle tdeg is greater than or equal to angle D (see Figure 17) (step S13).

[0095] Then, if the switching valve position angle tdeg is greater than or equal to angle D (step S13: YES), the control unit 14 determines whether or not the switching valve position angle tdeg is less than angle E (see Figure 17) (step S14).

[0096] Then, if the switching valve position angle tdeg is less than angle E (step S14: YES), the control unit 14 performs high-speed counterclockwise driving on the rotating disk 40 (step S15). That is, the control unit 14 rotates the rotating disk 40 counterclockwise at high speed.

[0097] In this way, as shown in Figure 17, when the rotating disk 40 is rotated counterclockwise to switch the flow path pattern from pattern A to pattern B, if the switching valve position angle tdeg is greater than or equal to angle D and less than angle E, that is, if the first sealing member 81A is not crossing the inflow passage 20 (for example, the second inflow passage 22 or the third inflow passage 23), the rotating disk 40 is rotated counterclockwise at high speed. Here, "high speed" refers to the normal speed when switching the flow path pattern.

[0098] On the other hand, if the switching valve position angle tdeg is greater than or equal to angle E (step S14: NO), the control unit 14 performs a low-speed counterclockwise drive on the rotating disk 40 (step S16) and determines whether or not the switching valve position angle tdeg is greater than or equal to angle H (step S11).

[0099] Furthermore, in step S13, if the switching valve position angle tdeg is less than angle D (step S13: NO), the control unit 14 performs a low-speed counterclockwise drive on the rotating disk 40 (step S6). That is, the control unit 14 rotates the rotating disk 40 counterclockwise at a low speed.

[0100] In this way, as shown in Figure 17, when the rotating disk 40 is rotating counterclockwise, if the switching valve position angle tdeg is greater than or equal to angle A and less than angle D, and if the switching valve position angle tdeg is greater than or equal to angle E and less than angle H, that is, if the first sealing member 81A is crossing the inflow passage 20 (for example, the second inflow passage 22 or the third inflow passage 23), the rotating disk 40 rotates counterclockwise at a low speed.

[0101] Furthermore, in step S12, if the switching A flag is "0" (step S12: NO), that is, if the rotating disk 40 is rotating clockwise to switch the flow path pattern from pattern B to pattern A, the control unit 14 determines whether the switching valve position angle tdeg is less than angle E (step S17).

[0102] Then, if the switching valve position angle tdeg is less than angle E (step S17: YES), the control unit 14 determines whether the switching valve position angle tdeg is greater than or equal to angle D (step S18).

[0103] Then, if the switching valve position angle tdeg is greater than or equal to angle D (step S18: YES), the control unit 14 performs a high-speed clockwise drive on the rotating disk 40 (step S19). That is, the control unit 14 rotates the rotating disk 40 at high speed clockwise.

[0104] On the other hand, if the switching valve position angle tdeg is less than angle D (step S18: NO), the control unit 14 performs a slow clockwise drive on the rotating disk 40 (step S20) and determines whether the switching valve position angle tdeg is less than angle A (step S7).

[0105] In this way, as shown in Figure 17, when the rotating disk 40 is rotated clockwise to switch the flow path pattern from pattern B to pattern A, if the switching valve position angle tdeg is greater than or equal to angle D and less than angle E, that is, if the first sealing member 81A is not crossing the inflow passage 20 (for example, the second inflow passage 22 or the third inflow passage 23), the rotating disk 40 is rotated clockwise at high speed.

[0106] On the other hand, if the switching valve position angle tdeg is greater than or equal to angle E (step S17: NO), the control unit 14 performs a slow clockwise drive on the rotating disk 40 (step S10). That is, the control unit 14 rotates the rotating disk 40 clockwise at a slow speed.

[0107] In this way, as shown in Figure 17, when the rotating disk 40 is rotated clockwise to switch the flow path pattern from pattern B to pattern A, if the switching valve position angle tdeg is greater than or equal to angle E and less than angle H, or if the switching valve position angle tdeg is greater than or equal to angle A and less than angle D, that is, if the first sealing member 81A is crossing the inflow passage 20 (for example, the second inflow passage 22 or the third inflow passage 23), the control unit 14 rotates the rotating disk 40 clockwise at a low speed.

[0108] Furthermore, if there is no request to switch the flow path pattern in step S2 (step S2: NO), the control unit 14 maintains the valve switching position (step S19), that is, it maintains the stopping position of the rotating disk 40.

[0109] By performing the control described above, as shown in Figure 17, when the rotating disk 40 is rotated counterclockwise to switch the flow path pattern from pattern A to pattern B, the rotating disk 40 is rotated counterclockwise at a low speed when the switching valve position angle tdeg is greater than or equal to angle A and less than angle D, and when the switching valve position angle tdeg is greater than or equal to angle E and less than angle H. On the other hand, when the switching valve position angle tdeg is greater than or equal to angle D and less than angle E, the rotating disk 40 is rotated counterclockwise at a high speed.

[0110] In other words, when the flow path pattern switches from pattern A to pattern B, the rotating disk 40 is rotated counterclockwise at a low speed when the first sealing member 81A crosses the inflow flow path 20, while the rotating disk 40 is rotated counterclockwise at a high speed when the first sealing member 81A does not cross the inflow flow path 20.

[0111] Furthermore, as shown in Figure 17, when the rotating disk 40 is rotated clockwise to switch the flow path pattern from pattern B to pattern A, the rotating disk 40 is rotated clockwise at a low speed when the switching valve position angle tdeg is greater than or equal to angle E and less than angle H, and when the switching valve position angle tdeg is greater than or equal to angle A and less than angle D. On the other hand, when the switching valve position angle tdeg is greater than or equal to angle D and less than angle E, the rotating disk 40 is rotated clockwise at a high speed.

[0112] In other words, when the flow path pattern switches from pattern B to pattern A, the rotating disk 40 is rotated clockwise at a low speed when the first sealing member 81A crosses the inflow flow path 20, while the rotating disk 40 is rotated clockwise at a high speed when the first sealing member 81A does not cross the inflow flow path 20.

[0113] In this way, when the rotating disk 40 is rotated to switch the flow path pattern between pattern A and pattern B, the rotating disk 40 rotates at a low speed when the first sealing member 81A crosses the inflow flow path 20, while the rotating disk 40 rotates at a high speed when the first sealing member 81A does not cross the inflow flow path 20.

[0114] As described above, when the control unit 14 rotates the rotating disk 40 to switch the flow path pattern, it reduces the rotation speed of the rotating disk 40 while the first sealing member 81A is crossing the inflow flow path 20 of the housing 11.

[0115] As a result, the location where localized stress occurs in the first sealing member 81A gradually shifts as the first sealing member 81A crosses the inflow channel 20 of the housing 11. Therefore, wear and cracking of the first sealing member 81A can be suppressed. Thus, the sealing performance of the first sealing member 81A can be ensured.

[0116] Furthermore, the first control relating to the rotational speed of the rotating disk 40 may be applied when the second sealing member 81B crosses the fixed disk communication passage 70 of the fixed disk 50.

[0117] (Regarding the second control related to the rotation speed of the rotating disk) As a second control relating to the rotational speed of the rotating disk 40, when the rotating disk 40 is rotated to switch the flow path pattern, the rotational speed of the rotating disk 40 may be further reduced when the first sealing member 81A transitions from crossing the inflow flow path 20 of the housing 11 to not crossing it.

[0118] Specifically, the control unit 14 performs the control shown in Figure 18 as a second control related to the rotational speed of the rotating disk 40. In the following explanation, only the differences from the first control related to the rotational speed of the rotating disk 40 shown in Figure 16 will be described.

[0119] As shown in Figure 18, in step S112, if the switching A flag is "1" (step S112: YES), that is, if the rotating disk 40 is rotated counterclockwise to switch the flow path pattern from pattern A to pattern B, the control unit 14 determines whether the switching valve position angle tdeg is greater than or equal to angle C (step S113).

[0120] Then, if the switching valve position angle tdeg is greater than or equal to angle C (step S113: YES), the control unit 14 performs an ultra-low speed drive of the rotating disk 40 in a counterclockwise direction (step S114). That is, the control unit 14 rotates the rotating disk 40 in a counterclockwise direction at an ultra-low speed. Here, "ultra-low speed" is a speed slower than low speed (for example, a speed of 1 / 3 of the normal speed), and is an example of the "second low speed" of this disclosure.

[0121] Next, the control unit 14 determines whether the switching valve position angle tdeg is less than angle D (step S115).

[0122] Then, if the switching valve position angle tdeg is less than angle D (step S115: YES), the control unit 14 continues to rotate the rotating disk 40 counterclockwise at an extremely low speed.

[0123] In this way, as shown in Figure 19, when the rotating disk 40 is rotated counterclockwise to switch the flow path pattern from pattern A to pattern B, the control unit 14 rotates the rotating disk 40 counterclockwise at an extremely low speed when the switching valve position angle tdeg is greater than or equal to angle C and less than angle D, that is, when the first sealing member 81A (the rear part in the direction of movement, the part located between angle C and angle D) transitions from crossing the inflow passage 20 of the housing 11 (for example, the third inflow passage 23) to not crossing it.

[0124] Furthermore, in step S117, if the switching valve position angle tdeg is greater than or equal to angle E (step S117: NO), the control unit 14 determines whether or not the switching valve position angle tdeg is greater than or equal to angle G (step S119).

[0125] Then, if the switching valve position angle tdeg is greater than or equal to angle G (step S119: YES), the control unit 14 performs an ultra-low speed drive in a counterclockwise direction (step S120). That is, the control unit 14 rotates the rotating disk 40 in a counterclockwise direction at an ultra-low speed.

[0126] Next, the control unit 14 determines whether the switching valve position angle tdeg is less than angle H (step S121).

[0127] Then, if the switching valve position angle tdeg is less than angle H (step S121: YES), the control unit 14 continues to rotate the rotating disk 40 counterclockwise at an extremely low speed.

[0128] In this way, as shown in Figure 19, when the rotating disk 40 is rotated counterclockwise to switch the flow path pattern from pattern A to pattern B, when the switching valve position angle tdeg is greater than or equal to angle G and less than angle H, that is, when the first seal member 81A (the forward part in the direction of movement, the part located between angle (G) and angle (H)) transitions from crossing the inflow passage 20 of the housing 11 (for example, the second inflow passage 22) to not crossing it, the control unit 14 rotates the rotating disk 40 counterclockwise at an extremely low speed.

[0129] Furthermore, in step S112, if the switching A flag is "0" (step S112: NO), that is, if the rotating disk 40 is rotated clockwise to switch the flow path pattern from pattern B to pattern A, the control unit 14 determines whether the switching valve position angle tdeg is less than angle F (step S122).

[0130] Then, if the switching valve position angle tdeg is less than angle F (step S122: YES), the control unit 14 performs an ultra-low speed drive clockwise on the rotating disk 40 (step S123). That is, the control unit 14 rotates the rotating disk 40 clockwise at an ultra-low speed.

[0131] Next, the control unit 14 determines whether the switching valve position angle tdeg is greater than or equal to angle E (step S124).

[0132] Then, if the switching valve position angle tdeg is greater than or equal to angle E (step S124: YES), the control unit 14 continues to rotate the rotating disk 40 clockwise at an extremely low speed.

[0133] In this way, as shown in Figure 19, when the rotating disk 40 is rotated clockwise to switch the flow path pattern from pattern B to pattern A, the control unit 14 rotates the rotating disk 40 clockwise at an extremely low speed when the switching valve position angle tdeg is greater than or equal to angle E and less than angle F, that is, when the first seal member 81A (the rear part in the direction of movement, the part located between angles (E) and (F)) transitions from crossing the inflow passage 20 of the housing 11 (for example, the second inflow passage 22) to not crossing it.

[0134] Furthermore, in step S126, if the switching valve position angle tdeg is less than angle D (step S126: NO), the control unit 14 determines whether or not the switching valve position angle tdeg is less than angle B (step S128).

[0135] Then, if the switching valve position angle tdeg is less than angle B (step S128: YES), the control unit 14 performs an ultra-low speed drive clockwise on the rotating disk 40 (step S129). That is, the control unit 14 rotates the rotating disk 40 clockwise at an ultra-low speed.

[0136] Next, the control unit 14 determines whether the switching valve position angle tdeg is greater than or equal to angle A (step S130).

[0137] Then, if the switching valve position angle tdeg is greater than or equal to angle A (step S130: YES), the control unit 14 continues to rotate the rotating disk 40 clockwise at an extremely low speed.

[0138] In this way, as shown in Figure 19, when the rotating disk 40 is rotated clockwise to switch the flow path pattern from pattern B to pattern A, the control unit 14 rotates the rotating disk 40 clockwise at an extremely low speed when the switching valve position angle tdeg is greater than or equal to angle A and less than angle B, that is, when the first seal member 81A (the forward portion in the direction of movement, the portion located between angle A and angle B) transitions from crossing the inflow passage 20 of the housing 11 (for example, the third inflow passage 23) to not crossing it.

[0139] As described above, when the control unit 14 rotates the rotating disk 40 to switch the flow path pattern, when the first sealing member 81A transitions from crossing the inflow flow path 20 of the housing 11 to not crossing it, it sets the rotation speed of the rotating disk 40 to an ultra-low speed, which is slower than the low speed.

[0140] As a result, when the first seal member 81A transitions from crossing the inflow channel 20 of the housing 11 to not crossing it, that is, when the non-contact portion of the first seal member 81A that is released into the inflow channel 20 of the housing 11 and not in contact with the housing 11 moves from inside the inflow channel 20 of the housing 11 to outside the inflow channel 20 and rides up onto the contact surface with the housing 11, the location where local stress is generated in the first seal member 81A is gradually moved. Therefore, wear and cracking of the first seal member 81A can be suppressed more effectively. Consequently, the sealing performance of the first seal member 81A can be ensured more effectively.

[0141] Furthermore, the second control relating to the rotational speed of the rotating disk 40 may be applied when the second sealing member 81B crosses the fixed disk communication passage 70 of the fixed disk 50.

[0142] (Regarding the sliding flow path switching device) The contents of this disclosure described above can also be applied to the flow path switching device 2 shown in Figures 20 to 23. As shown in Figures 20 to 23, the flow path switching device 2 has a housing 211, a slide valve 212, and a drive unit 213.

[0143] The housing 211 is equipped with flow ports 220 through which fluid flows in or out. Here, the flow switching device 2 is, for example, a hexagonal valve, and the housing 211 is equipped with six flow ports 220. The housing 211 is formed of, for example, resin, and is an example of a “fixing member” in this disclosure. The flow ports 220 are an example of a “port” in this disclosure.

[0144] The slide valve 212 is located inside the housing 211. The slide valve 212 is formed of, for example, resin, and is an example of a "drive member" in this disclosure.

[0145] The slide valve 212 is formed in the shape of a rectangular plate (i.e., a roughly rectangular parallelepiped) and has at least one slide valve communication passage 260. Here, the slide valve 212 has four slide valve communication passages 260 as an example. Note that the slide valve communication passage 260 is an example of a "communication passage" as described herein.

[0146] The drive unit 213 includes an actuator (not shown) for providing power to drive the slide valve 212.

[0147] Furthermore, as shown in Figure 21, a sealing member 281 is provided between the housing 211 and the slide valve 212. In addition, stress is acting on the slide valve 212 due to the biasing force of the spring 282.

[0148] The sealing member 281 is formed of, for example, a fluororesin (e.g., Teflon®). Alternatively, the sealing member 281 may be formed of rubber with a fluororesin coating. Furthermore, the sealing member 281 may be formed of a material other than fluororesin or rubber.

[0149] In this configuration, the flow path switching device 2 forms a flow path by combining the flow path opening 220 of the housing 211 with the slide valve communication passage 260. As shown in Figures 20 to 23, the flow path switching device 2 drives the slide valve 212 to slide in the axial direction of the drive shaft 213a by the drive shaft 213a of the drive unit 213, thereby changing the combination of communication between the flow path opening 220 and the slide valve communication passage 260, and switching the flow path pattern between the first flow path pattern shown in Figures 20 and 21 and the second flow path pattern shown in Figures 22 and 23.

[0150] Furthermore, in this flow path switching device 2, the slide valve 212 is made more rigid than the housing 211.

[0151] Furthermore, the edge of the opening on the slide valve 212 side of the flow channel port 220 of the housing 211 may have a radius (R) or taper, similar to the flow channel switching device 1.

[0152] Furthermore, when sliding the slide valve 212 to switch the flow path pattern, the driving speed (sliding speed) of the slide valve 212 may be set to a slower speed than the normal speed while the sealing member 281 is crossing the flow path opening 220 of the housing 211.

[0153] Furthermore, when the slide valve 212 is slid to switch the flow path pattern, the drive speed of the slide valve 212 may be set to an ultra-low speed, which is slower than a low speed, when the sealing member 281 transitions from crossing the flow path opening 220 of the housing 211 to not crossing it.

[0154] [Second Embodiment] Next, the second embodiment will be described, explaining the differences from the first embodiment, and omitting the explanation of the points that are common to the first embodiment. Here, the flow path switching device 1 will be described.

[0155] Consider the case where the rotating disk 40 rotates, and as shown in Figure 34, the first sealing member 81A moves from the first end 20b to the second end 20c between the first end 20b and the second end 20c on the opposite side (left side in the figure) from the direction of rotation of the rotating disk 40 (right in the figure).

[0156] At this time, as shown in Figure 35, the length of the portion of the first seal member 81A that is temporarily released into the inflow channel 20, that is, the non-contact portion that is released into the inflow channel 20 and does not come into contact with the housing 11 (hereinafter, as appropriate, simply referred to as the "non-contact portion with the housing 11"), gradually increases, so that tensile stress is generated. At this time, the amount Lc of the non-contact portion of the first seal member 81A that protrudes into the inflow channel 20 is as shown in Figure 35. Also, as shown in Figure 34, the tensile stress is at its maximum (max) at the position of the second end portion 20c.

[0157] Next, consider the case where the rotating disk 40 rotates, and the first sealing member 81A moves from the second end 20c towards the first end 20b between the second end 20c and the first end 20b on the rotational direction side (right side in the figure) of the rotating disk 40, as shown in Figure 36.

[0158] At this time, as shown in Figure 37, the length of the non-contact portion of the first seal member 81A with respect to the housing 11 gradually decreases, generating compressive stress. Also, the amount Ld of the non-contact portion of the first seal member 81A protruding into the inflow channel 20 is as shown in Figure 37. Note that the amount Ld protruding is greater than the amount Lc protruding (see Figure 35). Then, as shown in Figure 36, the compressive stress is at its maximum (max) at the position of the first end 20b on the rotational direction side of the rotating disk 40.

[0159] Subsequently, as the rotating disk 40 rotates, the non-contact portion of the first sealing member 81A with respect to the housing 11 is pushed up by the edge 20a of the opening and rides onto the first end 20b of the edge 20a of the opening. Then, the first sealing member 81A slides from the edge 20a of the opening to the surface 11a of the housing 11 on the side of the rotating disk 40.

[0160] In this embodiment, a curved shape (R) is formed on the edge 20a of the opening on the rotating disk 40 side of the inflow channel 20 of the housing 11. The size of R (i.e., the radius of R) is larger at the position of the first end 20b of the edge 20a of the opening than at the position of the second end 20c of the edge 20a of the opening. Alternatively, a taper may be formed instead of R, in which case the size of the taper is the angle of inclination of the taper.

[0161] In this embodiment, as shown in Figure 27, both the inner circumference LA and the outer circumference LB of the edge 20a of the circumferentially formed opening are formed in a circular shape. Specifically, the inner circumference LA is formed in a circular shape with a diameter D1, and the outer circumference LB is formed in a circular shape with a diameter D2. Note that diameter D2 is larger than diameter D1. In Figure 27 and other figures, for the sake of explanation, the direction of movement of the rotating disk 40 is shown as the left-right direction in the drawing.

[0162] Thus, in this embodiment, as shown in Figures 27 and 28, at the first end 20b and the second end 20c of the edge 20a of the opening, the radius r1 of the inner circumference LA of the edge 20a of the opening and the radius r2 of the outer circumference LB of the edge 20a of the opening are equal or approximately equal.

[0163] The radius r1 of the inner circumference LA of the edge 20a of the opening is the opening radius. The radius r2 of the outer circumference LB of the edge 20a of the opening is the radius of the boundary line between R at the edge 20a of the opening and the surface 11a of the housing 11.

[0164] In this embodiment, as shown in Figure 28(B), the position of the center point of R of the first end portion 20b is moved (i.e., offset) to the lower side of the drawing (i.e., opposite to the opening of the inflow channel 20) than the position of the center point of R of the second end portion 20c shown in Figure 28(A), thereby increasing the size of R of the first end portion 20b without increasing the radius r2 of the outer circumference LB of the edge 20a of the opening.

[0165] In this embodiment, the size of R is made larger at the first end 20b than at the second end 20c, while the radius r1 of the inner circumference LA of the opening edge 20a at the first end 20b and the radius r1 of the inner circumference LA of the opening edge 20a at the second end 20c are made equal or approximately equal. Furthermore, the radius r2 of the outer circumference LB of the opening edge 20a at the first end 20b and the radius r2 of the outer circumference LB of the opening edge 20a at the second end 20c are made equal or approximately equal.

[0166] As a result, in this embodiment, as shown in Figure 29, the position of the inner circumference LA of the edge 20a of the opening is higher in the drawing (i.e., on the side that pushes up the first sealing member 81A) than in the first embodiment (see Figure 40).

[0167] As a result, the rotating disk 40 rotates relative to the housing 11 to switch the flow path pattern, and when the first seal member 81A passes through the inflow channel 20, as shown in Figure 29, the non-contact portion of the first seal member 81A with respect to the housing 11 rides up onto the first end 20b of the edge 20a of the opening, and is pushed up to the vicinity of the first end 20b of the edge 20a of the opening (the portion indicated by the dotted line GG in the figure, corresponding to the position of GG in Figure 27). This effectively pushes up the non-contact portion of the first seal member 81A with respect to the housing 11. Therefore, the non-contact portion of the first seal member 81A with respect to the housing 11 can smoothly ride up onto the first end 20b of the edge 20a of the opening. Consequently, the first seal member 81A can smoothly pass through the inflow channel 20.

[0168] Furthermore, in the comparative example shown in Figure 39, where the radius of the first end portion 20b is equal to the radius of the second end portion 20c, just before the non-contact portion of the first sealing member 81A with respect to the housing 11 rides onto the first end portion 20b of the edge 20a of the opening, the non-contact portion of the first sealing member 81A with respect to the housing 11 cannot ride onto it smoothly, making it prone to stress concentration due to compressive stress.

[0169] However, according to this embodiment, since the size of R is larger at the first end 20b than at the second end 20c, stress concentration due to compressive stress is suppressed at the non-contact portion of the first seal member 81A with respect to the housing 11 just before the non-contact portion of the first seal member 81A with respect to the housing 11 rides onto the first end 20b of the edge 20a of the opening. Therefore, according to this embodiment, the non-contact portion of the first seal member 81A with respect to the housing 11 can ride onto the first end 20b of the edge 20a of the opening more smoothly than in the comparative example shown in Figure 39.

[0170] Furthermore, according to this embodiment, compared to the first embodiment shown in Figure 40, when the non-contact portion of the first sealing member 81A with respect to the housing 11 rides up onto the first end portion 20b of the edge 20a of the opening, the non-contact portion of the first sealing member 81A with respect to the housing 11 can be effectively pushed up. Therefore, according to this embodiment, the non-contact portion of the first sealing member 81A with respect to the housing 11 can ride up onto the edge 20a of the opening more smoothly than in the first embodiment shown in Figure 40.

[0171] Furthermore, according to this embodiment, as shown in Figure 29, the size of R at the first end 20b is larger than (r2-r1). (r2-r1) is the value obtained by subtracting the radius r1 of the inner circumference LA of the edge 20a of the opening from the radius r2 of the outer circumference LB of the edge 20a of the opening. In this way, in this embodiment, the size of R is reliably increased at the first end 20b of the edge 20a of the opening. Therefore, when the non-contact portion of the first seal member 81A with respect to the housing 11 rides up onto the first end 20b of the edge 20a of the opening, the first seal member 81A can be pushed up more reliably and effectively. In addition, wear of the first seal member 81A can be suppressed.

[0172] Furthermore, as shown in Figure 27, the distance between the two first ends 20b in this embodiment (corresponding to D2 shown in the figure) can be made smaller than the distance between the two first ends 20b in the first embodiment shown in Figure 41 (D3 shown in the figure).

[0173] This makes it possible to shorten the length L2 of the first seal member 81A in this embodiment (i.e., the length in the rotational direction of the rotating disk 40) compared to the length L1 of the first seal member 81A in the first embodiment. Therefore, the sliding resistance between the first seal member 81A and the housing 11 can be suppressed, thereby suppressing the increase in the rotational torque of the rotating disk 40.

[0174] As a first modification, as shown in Figure 30, the shape of the edge 20a of the opening as viewed from the rotating disk 40 side may be a flattened circular shape. Specifically, the first opening curvature CU1, which is the curvature at the first end 20b, may be made smaller than the second opening curvature CU2, which is the curvature at the second end 20c. That is, as shown in Figure 30, the radius of curvature at the second end 20c may be made smaller, while the radius of curvature at the first end 20b may be made larger.

[0175] Furthermore, as you move from the second end 20c towards the first end 20b, the curvature of the edge 20a of the opening will gradually decrease (i.e., the radius of curvature of the edge 20a of the opening will gradually increase), thus changing gradually.

[0176] In this way, in the first modified example, the curvature at the first end 20b (i.e., the first opening curvature CU1) of the edge 20a of the opening is reduced.

[0177] As a result, when the rotating disk 40 rotates relative to the housing 11 and the first seal member 81A passes through the inflow channel 20, the compressive stress acting on the first seal member 81A is suppressed just before the non-contact portion of the first seal member 81A with respect to the housing 11 rides onto the first end portion 20b of the edge 20a of the opening. Therefore, the amount of the non-contact portion of the first seal member 81A that protrudes into the inflow channel 20 is reduced. Consequently, the first seal member 81A can ride onto the first end portion 20b of the edge 20a of the opening smoothly.

[0178] As a second modification, as shown in Figure 31, the shape of the edge 20a of the opening when viewed from the rotating disk 40 side may have a straight portion 101 formed in a straight line at the first end 20b so as to be perpendicular to the rotation direction of the rotating disk 40 (left-right direction in Figure 31). Note that the straight portion 101 is an example of the "edge straight portion" of this disclosure.

[0179] In this modified example, as shown in Figure 31, the shape of the edge 20a of the opening is such that a straight portion 101 is formed linearly in the direction of rotation of the rotating disk 40 (left-right direction in Figure 31) at the second end 20c, and a circular portion 102 with radius LR is formed between the two straight portions 101.

[0180] As a result, similar to the first modified example, when the first sealing member 81A passes through the inflow channel 20, the compressive stress acting on the first sealing member 81A is suppressed just before the non-contact portion of the first sealing member 81A with respect to the housing 11 rides up onto the first end portion 20b of the edge 20a of the opening.

[0181] As shown in Figure 32, regarding the shape of the edge 20a of the opening when viewed from the rotating disk 40 side, a straight portion 101 may be formed at the first end 20b, while a straight portion 101 may not be formed at the second end 20c.

[0182] Furthermore, as a third modification, as shown in Figure 33, the shape of the first sealing member 81A may have a straight portion 111 at the end in the direction of rotation of the rotating disk 40 (left-right direction in Figure 33). This straight portion 111 is formed in a straight line perpendicular to the direction of rotation of the rotating disk 40. Note that the straight portion 111 is an example of the "sealing member straight portion" of this disclosure. Alternatively, instead of the straight portion 111, a substantially straight portion 111a (also called a small curvature portion that is curved with a small curvature) may be formed in a substantially straight line. Note that this substantially straight portion 111a is an example of the "sealing member substantially straight portion" of this disclosure.

[0183] In this modified example, as shown in Figure 33, the shape of the first sealing member 81A is such that a straight portion 111 or a substantially straight portion 111a is formed in the part passing through the first end portion 20b, and circular portions 112 are formed on both sides of the straight portion 111 or substantially straight portion 111a. The circular portion 112 is the circumference of a circle with radius RA.

[0184] In this way, the shape of the first sealing member 81A is such that its end in the direction of rotation of the rotating disk 40, that is, the portion that is temporarily released into the inflow channel 20 and rides up on the first end 20b of the edge 20a of the opening (i.e., the portion that does not come into contact with the housing 11) when the first sealing member 81A passes through the inflow channel 20 as the rotating disk 40 rotates relative to the housing 11, is formed in a straight line perpendicular to the direction of rotation of the rotating disk 40.

[0185] As a result, the compressive stress acting on the first seal member 81A is suppressed just before the non-contact portion of the first seal member 81A with respect to the housing 11 rides onto the first end 20b of the edge 20a of the opening. Therefore, the amount of the first seal member 81A protruding into the inflow channel 20 is reduced. Consequently, the first seal member 81A can smoothly ride onto the first end 20b of the edge 20a of the opening.

[0186] It should be noted that the embodiments described above are merely illustrative examples and do not limit this disclosure in any way. Various improvements and modifications are possible without departing from the gist of the disclosure.

[0187] For example, when the rotating disk 40 rotates, the second sealing member 81B passes through the fixed disk communication passage 70 of the fixed disk 50, and the contents of the second embodiment and each modified example shall also apply to the fixed disk communication passage 70 and the second sealing member 81B. [Explanation of Symbols]

[0188] 1,2 Flow path switching device 11 Housing 12 Valve body 14 Control Unit 20 Inflow channel 20a Edge 20b 1st end 20c 2nd end 21. First Inflow Channel 22 Second Inflow Channel 23 Third Inflow Channel 30 Outlet channel 31. First Outflow Channel 32 Second Outflow Channel 33 Third Outflow Channel 40 RPM disc 41 Disc section 50 fixed disks 51 Disc section 60 RPM disc driveway 61. First Rotating Disc Linkage 62 Second Rotating Disc Linkage 63 Third Rotation Disc Linkage 70 Fixed disk driveway 71 First fixed disk connecting passage 72 Second Fixed Disk Linkage 73 Third Fixed Disk Linkage 81A First sealing member 81B Second sealing member 101 Straight section 111 Straight section 111a Shortly straight section 211 Housing 212 Slide Valve 220 Channel mouth 260 Slide valve connecting passage 281 Sealing member L center axis LA (inner circumference of the opening edge) LB (outer edge of the opening) r1 radius r2 radius CU1 1st opening curvature CU2 2nd opening curvature

Claims

1. A fixing member is provided, Having a drive member, The aforementioned fixing member is equipped with a port, The drive member is provided with a communication passage, In a flow path switching device that connects the port of the fixed member and the communication passage of the drive member to form a flow path through which fluid flows, The drive member has a sealing member that is provided on the drive member and contacts the fixed member when a pressing force is applied, sealing the space between the port of the fixed member and the communication passage of the drive member that communicates with the port of the fixed member, The drive member has higher rigidity than at least one of the fixed members. The aforementioned fixing member includes a first fixing member and a second fixing member. The drive member is positioned between the first fixing member and the second fixing member. The sealing member includes a first sealing member provided between the first fixing member and the driving member, and a second sealing member provided between the driving member and the second fixing member. The drive member is held between the first fixing member and the second fixing member in a state in which the pressing force is applied via the second fixing member and the second sealing member. The port of the second fixing member is positioned so that the second sealing member does not cross it when the driving member is driven to switch the flow path pattern. A flow path switching device characterized by the following.

2. In the flow path switching device of Claim 1, The edge of the opening on the drive member side of the port of the fixed member has a radius or taper formed thereon. The size of R or the size of the taper is such that the first end, which is the end of the opening edge in the driving direction of the drive member, is larger than the second end, which is the end of the opening edge in a direction perpendicular to the driving direction of the drive member, and gradually decreases from the first end toward the second end. A flow path switching device characterized by the following.

3. In the flow path switching device according to claim 1 or 2, When the drive member is driven to switch the flow path pattern, the drive speed of the drive member is set to a first low speed, which is slower than the normal speed, while the sealing member is crossing the port of the fixed member. A flow path switching device characterized by the following.

4. In the flow path switching device of claim 3, When the drive member is driven to switch the flow path pattern, when the sealing member transitions from crossing the port of the fixed member to not crossing it, the drive speed of the drive member is set to a second low speed that is slower than the first low speed. A flow path switching device characterized by the following.

5. In the flow path switching device according to claim 1 or 2, The edge of the opening on the drive member side of the port of the fixed member has a radius or taper formed thereon. The size of R or the size of the taper is greater at the first end, which is the end of the opening edge in the driving direction of the drive member, than at the second end, which is the end of the opening edge in a direction perpendicular to the driving direction of the drive member. and, At the first end and the second end, the radius of the inner circumference of the edge of the opening and the radius of the outer circumference of the edge of the opening are equal or approximately equal, respectively. A flow path switching device characterized by the following.

6. In the flow path switching device of claim 5, When the inner radius of the edge of the opening is r1 and the outer radius of the edge of the opening is r2, the size of R at the first end is greater than (r2 - r1). A flow path switching device characterized by the following.

7. In the flow path switching device according to claim 1 or 2, Regarding the shape of the edge of the opening on the drive member side in the port of the fixed member, the first opening curvature, which is the curvature at the first end of the edge of the opening that is the end in the driving direction of the drive member, is smaller than the second opening curvature, which is the curvature at the second end of the edge of the opening that is the end in a direction perpendicular to the driving direction of the drive member. A flow path switching device characterized by the following.

8. In the flow path switching device according to claim 1 or 2, Regarding the shape of the edge of the opening on the drive member side in the port of the fixed member, a straight edge portion is formed at the first end, which is the end of the opening in the driving direction of the drive member, so as to be perpendicular to the driving direction. A flow path switching device characterized by the following.

9. In the flow path switching device according to claim 1 or 2, Regarding the shape of the sealing member, a straight portion of the sealing member is formed in a straight line, or a substantially straight portion of the sealing member is formed in a substantially straight line, at the end of the driving member in the driving direction, perpendicular to the driving direction. A flow path switching device characterized by the following.

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