Rotary valve

Abstract

To improve the assembling performance of a valve body.SOLUTION: A housing 15 has an annular wall part 22 at which package attachment parts 33, 37 are formed. In a rotary valve 10, a communication state between an inlet port and an outlet port provided at the housing 15 is changed by a change of a rotation phase of a valve body 41 having a valve main body part 42. An external peripheral face 46 of the valve main body part 42 has a large-diameter part 51 and a small-diameter part 52. The rotation phase includes a rotation phase at which the small-diameter part 52 opposes all packings 55, 56. A portion in which thicknesses of the packing attachment parts 33, 37 in a radial direction are minimum is set as a thickness minimum part 60. An interval between an axial line AL and a portion with which the thickness minimum part 60 out of internal bottom faces 33a, 37a of the packing attachment parts 33, 37 contacts is set as an attachment part dimension D. A radius A of the large-diameter part 51, a radius B of the small-diameter part 52, a minimum thickness C at the thickness minimum part 60, and the attachment part dimension D satisfy (formula 1): B<A, (formula 2): D-C<A, and (formula 3): D-C-B<C.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a rotary valve that changes the state of communication between an inlet and an outlet by rotating a valve element. [Background technology]

[0002] As shown in FIG. 14, a rotary valve 70 is known that includes a housing 71 having an annular wall portion 72, a valve body 76, and a packing 81 (see, for example, Patent Document 1). The housing 71 is formed with an inlet 73 for a fluid FL. Furthermore, outlets 74, 75 for the fluid FL are formed at a plurality of locations (two locations in FIG. 14) on the annular wall portion 72. The valve body 76 includes a cylindrical valve body portion 77 disposed within the annular wall portion 72. The valve body 76 is rotatably supported by the housing 71 by a shaft portion 79. The valve body portion 77 is formed with a movable flow path 78 that communicates the inlet 73 with the outlets 74, 75. The packing 81 is disposed between the peripheral edge portions of the annular wall portion 72 at each of the outlets 74, 75 and an outer circumferential surface 80 of the valve body portion 77.

[0003] The rotational phase of the valve body 76 changes as the valve body 76 rotates about the shaft portion 79, whereby the communication state between the inlet 73 and the outlets 74, 75 changes. 14 , for example, the packing 81 is compressed radially outwardly of the annular wall portion 72 by the outer circumferential surface 80 of the valve body portion 77. The packing 81 is elastically deformed in the radial direction, thereby sealing the space between the annular wall portion 72 and the valve body portion 77 around the outlet 74. The outlet 74 is closed by the valve body portion 77 via the packing 81. The fluid FL in the annular wall portion 72 is restricted from flowing out of the rotary valve 70 from the outlet 74.

[0004] In the conventional rotary valve 70, when the valve body 76 is assembled, the packing 81 is first fitted inside the annular wall portion 72. Then, in this state, the valve body portion 77 is housed inside the annular wall portion 72.

[0005] As described above, since sealing is achieved by elastically deforming the gasket 81 in the radial direction, the inner diameter (diameter) of the space within the annular wall portion 72 in which the valve main body portion 77 is accommodated is smaller than the outer diameter (diameter) of the valve main body portion 77 before the valve body 76 is assembled.

[0006] In order to insert the valve body 77 into a small space as described above, the conventional rotary valve 70 employs one of the following methods. The packing 81 is compressed outward in the radial direction using a jig to elastically deform it, temporarily expanding the space in which the valve main body 77 is accommodated. The valve main body 77 is inserted into the expanded space, and then the jig is removed.

[0007] The valve body 77 is forcefully inserted into the small space without using a jig. That is, the valve body 77 compresses the packing 81 outward in the radial direction by the valve body 77, thereby expanding the space, and the valve body 77 is inserted into the space. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent Publication No. 2021-55705 Summary of the Invention [Problem to be solved by the invention]

[0009] However, in the former method, the step of elastically deforming packing 81 in the radial direction by a jig and the step of inserting valve body 77 are carried out separately. The number of assembly steps increases by the amount of elastic deformation by the jig.

[0010] In the latter method, when the valve body 77 is inserted into the annular wall portion 72, a large reaction force is applied from the packing 81. Therefore, it is difficult to insert the valve body 77 into the annular wall portion 72. Therefore, in both of the above methods, there is still room for improvement in terms of ease of assembly of the valve body 76.

Means for Solving the Problem

[0011] Each aspect of the rotary valve for solving the above problems will be described. [Aspect 1] A housing having a fluid inlet and an outlet, and a valve body. The housing includes an annular wall portion that extends along the axis while surrounding the axis and has the outlet at one or more locations in its circumferential direction. The valve body includes a cylindrical valve body portion housed in the annular wall portion. In the annular wall portion, a packing mounting portion is formed at a location inward in the radial direction with respect to the peripheral edge of each outlet. A packing is mounted on the packing mounting portion, and the inner surface in the radial direction is curved in a concave shape along the outer peripheral surface of the valve body portion. As the rotation phase changes with the rotation of the valve body about the axis, the communication state between the inlet and the outlet is changed. The rotary valve is such that the outer peripheral surface of the valve body portion seals between the annular wall portion and the valve body portion around the outlet by elastically deforming the packing in the radial direction. The outer peripheral surface of the valve body portion includes a large-diameter portion that seals between the annular wall portion and the valve body portion around the outlet by elastically deforming the packing in the radial direction, and a small-diameter portion located at a different location in the circumferential direction of the valve body portion with respect to the large-diameter portion. The rotation phase includes a rotation phase in which the small-diameter portion faces all the packings. Let the radius of the large-diameter portion be radius A, the radius of the small-diameter portion be radius B, the location where the thickness of the packing in the radial direction is minimum be the minimum-thickness portion, the thickness at the minimum-thickness portion be the minimum thickness C, and the distance between the axis and the location where the minimum-thickness portion contacts the inner bottom surface of the packing mounting portion be the mounting portion dimension D. In this case, the radius A, the radius B, the minimum thickness C, and the mounting portion dimension D satisfy (Equation 1) to (Equation 3). B < A ··· (Equation 1) D - C < A ··· (Equation 2) D - C - B < C ··· (Equation 3) Rotary valve.

[0012] According to the above-mentioned configuration, when assembling the valve body, the packing is first attached to the packing attachment portion. Next, the valve body portion of the valve body is inserted into the annular wall portion. This insertion is performed in a state where the small diameter portion is in a rotational phase facing all of the packings.

[0013] Since the radius B of the small diameter portion is smaller than the radius A of the large diameter portion, the small diameter portion does not interfere with the packing during the above-mentioned insertion, or interferes little with it. In the latter case, the degree of interference is smaller than when the radius of the valve body is the same as the radius A of the large diameter portion over the entire circumference, or when the large diameter portion faces at least one packing. Therefore, the valve body can be easily inserted into the annular wall portion.

[0014] If a gap occurs between the small diameter portion and the packing, and if the gap is too large, the packing may fall over in the gap when the valve body is inserted into the annular wall portion. The valve body must be inserted into the annular wall portion in a manner that prevents the packing from falling over, which reduces the efficiency of the insertion process. There is also a risk that the valve body may be inserted with the packing in a fallen state.

[0015] In this regard, the gap between the small diameter portion and the packing is smaller than the minimum thickness C. No excessive gap is generated between the small diameter portion and the packing. Therefore, when the valve body is inserted into the annular wall portion, the packing is prevented from falling over in the gap, improving the ease of insertion. Even if the packing falls over, it will not move significantly from its position before it falls over, making the insertion easier.

[0016] When the rotary valve is in operation, the valve body rotates about its axis. When the large diameter portion faces the packing, the packing is compressed radially outward and elastically deformed in the same radial direction. A seal is formed between the annular wall portion and the valve body portion around the outlet. The outlet is blocked by the large diameter portion via the packing. Fluid within the annular wall portion is restricted from flowing out of the rotary valve through the packing and the outlet.

[0017] [Aspect 2] The radius B, the minimum thickness C, and the mounting portion dimension D satisfy (Equation 4). B≦DC (Formula 4) The rotary valve according to [Aspect 1].

[0018] According to the above configuration, the small diameter portion is less likely to interfere with the packing during the above insertion, compared to when the radius B is greater than the mounting portion dimension D minus the minimum thickness C. The valve body is easier to insert into the annular wall portion.

[0019] [Aspect 3] A rotary valve as described in [Aspect 2], wherein the combination of the outlet and the gasket mounting portion is formed at two locations in the circumferential direction of the annular wall portion, and the rotational phase includes a rotational phase in which the large diameter portion faces only one of the gaskets.

[0020] According to the above-mentioned configuration, when the rotary valve is operated, the valve body is rotated to a rotational phase where the large diameter portion faces only one of the packings, and the packing is elastically deformed by the large diameter portion. Around the outer outlet of the packing in the radial direction, the gap between the annular wall portion and the valve body portion is sealed by the packing.

[0021] The large diameter portion is spaced from the other packing, in this case the packing at the portion not requiring sealing, in the circumferential direction of the annular wall portion. The flow outlet on the outer side of the packing in the radial direction is entirely open.

[0022] Therefore, the fluid that flows into the annular wall through the inlet passes through the valve body, then passes through the other packing and the outlet on the radial outside of the other packing, and is then discharged to the outside of the rotary valve. On the other hand, the fluid is restricted from flowing out to the outside of the rotary valve through the one packing and the outlet on the radial outside of the one packing.

[0023] In addition, as described above, the large diameter portion elastically deforms only the packing in the area that requires sealing. Therefore, compared to when the large diameter portion elastically deforms the packing in areas that do not require sealing, extra load is less likely to be applied to the valve body. Small torque is required to rotate the valve body.

[0024] [Aspect 4] The large diameter portion and the small diameter portion are connected by a pair of flat portions provided between the large diameter portion and the small diameter portion, and an angle α between a tangent at a boundary portion between the small diameter portion and each flat portion and the flat portion satisfies (Equation 5). 170°≦α<180° (Formula 5) A rotary valve according to [Aspect 2] or [Aspect 3].

[0025] According to the above-mentioned configuration, in the rotation phase in which the small diameter portion faces the packing, the small diameter portion does not interfere with the packing, or if it does interfere, it is only slightly. When the valve body rotates from the above rotation phase to a rotation phase where the large diameter portion faces the packing, the boundary between the large diameter portion and the flat portion interferes with the packing. When the valve body rotates further, the large diameter portion rides on the packing. The large diameter portion compresses the packing radially outward, elastically deforming the packing in the radial direction.

[0026] When the large diameter portion rides on the packing, it encounters resistance from the packing and gets caught. The magnitude of this resistance varies depending on the angle α that the tangent line at the boundary between the small diameter portion and the flat portion makes with the flat portion. As the angle α increases, the large diameter portion and the flat portion connect more gently, and the resistance that the large diameter portion experiences from the packing is smaller. In contrast, as the angle α decreases, the large diameter portion and the flat portion become more pointed, and the resistance that the large diameter portion experiences from the packing increases. As a result, the rotational torque required to rotate the valve body increases.

[0027] In this regard, by setting the angle α to satisfy the relationship 170°≦α<180° as in the above configuration, the large diameter portion and the flat portion are gradually connected. When the large diameter portion rides on the packing, the resistance from the packing is reduced. Therefore, the rotational torque required to rotate the valve body is small.

[0028] [Aspect 5] A rotary valve as described in [Aspect 3], wherein the combinations of the two gasket mounting portions and the gaskets mounted on each gasket mounting portion are adjacent to each other in the circumferential direction in a portion of the circumferential direction of the annular wall portion, the valve body has a shaft portion extending along the axis on the axis, a bearing hole is formed in the housing through which the shaft portion is inserted, and an annular shaft seal member is arranged around the shaft portion between the coaxial portion and the inner wall surface of the bearing hole.

[0029] When the large diameter portion elastically deforms the packing, a reaction force is generated in association with the elastic deformation. This reaction force acts on the large diameter portion. If the large diameter portion faces the entirety of one packing and the entirety of the other packing at the same time, reaction forces from both packings act on the large diameter portion. More specifically, a load consisting of the combined reaction forces of both packings acts on the large diameter portion. This load is directed toward the side of the shaft portion where neither packing is located, across the axis of the shaft portion. The load is transmitted as an unbalanced load from one direction in the radial direction of the valve body via the valve body portion and the shaft portion to the shaft seal member.

[0030] In this regard, according to the above-mentioned configuration, the large diameter portion faces only one of the packings, or faces a part of one packing and a part of the other packing across the gap, so the offset load acting on the shaft seal member is smaller than when the large diameter portion faces the entire one packing and the entire other packing at the same time. Effect of the Invention

[0031] According to the present invention, the ease of assembly of the valve body can be improved. [Brief description of the drawings]

[0032] [Figure 1] FIG. 1 is a perspective view of a rotary valve according to an embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of components of the rotary valve in the embodiment, as viewed from the body side. [Diagram 3] FIG. 2 is an exploded perspective view of components of the rotary valve in the embodiment, as viewed from the cover side. [Figure 4] FIG. 2 is a perspective view showing a state before a valve body is assembled to an annular wall portion to which a packing is attached in the embodiment. [Diagram 5] FIG. 2 is a vertical sectional view of the rotary valve in the embodiment. [Figure 6] FIG. 4 is a partial bottom cross-sectional view of the rotary valve in the embodiment, in which the valve body is in a rotational phase in which it blocks a part of the packing, the first outlet, and the second outlet. [Figure 7] FIG. 2 is a partial bottom view of the rotary valve after the valve body has been assembled to the annular wall portion to which the packing is attached and before the cover is attached in the embodiment. [Figure 8] FIG. 2 is a partial bottom cross-sectional view of the rotary valve in the embodiment, in which a valve body is assembled to an annular wall portion to which a packing is attached. [Figure 9] FIG. 8 is a partial bottom view of the rotary valve in FIG. 7 in which the valve body is rotated so that the large diameter portion faces only one of the packings. [Figure 10] 9 is a partial bottom cross-sectional view of the rotary valve in FIG. 8 in which the valve body is rotated so that the large diameter portion faces only one of the packings. FIG. [Figure 11] FIG. 8 is a diagram showing a part of FIG. 7, being a partial bottom view for explaining the dimensional relationship of each part of the rotary valve. [Figure 12] 5 is a schematic diagram illustrating an action when the valve disc of the above embodiment, in which the angle α satisfies (Equation 5), is rotated and the large diameter portion rides on the packing. FIG. [Figure 13] 5 is a schematic diagram illustrating an action when a valve disc of a comparative example in which the angle α does not satisfy (Formula 5) is rotated and the large diameter portion rides on the packing. FIG. [Figure 14] FIG. 11 is a diagram showing a conventional rotary valve, and is a partial bottom cross-sectional view corresponding to FIG. 10. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, one embodiment of a rotary valve will be described with reference to FIGS. As shown in FIG. 1, the rotary valve 10 is provided in the middle of a flow path 11 of a fluid FL such as water supplied from a fluid supply source such as a pump (not shown). More specifically, the flow path 11 includes a common flow path 12 connected to the fluid supply source, and a first branch flow path 13 and a second branch flow path 14 branched from the common flow path 12. The rotary valve 10 is disposed at a portion where the first branch flow path 13 and the second branch flow path 14 branch from the common flow path 12. The rotary valve 10 plays a role in adjusting the flow rate of the fluid FL flowing through the first branch flow path 13 and the second branch flow path 14. By adjusting the flow rate, it is possible to cause the fluid FL to flow through both the first branch flow path 13 and the second branch flow path 14 as shown in FIG. 6, or to flow only through the second branch flow path 14 in this embodiment as shown in FIG. 10.

[0034] 1 to 3, the rotary valve 10 includes a housing 15, a valve body 41, a pair of packings 55, 56, and a shaft seal member 61. Here, the valve body 41 is rotatable about shafts 48, 49 having an axis AL, as described below. Therefore, each member will be described based on this axis AL.

[0035] <Housing 15> The housing 15 includes a plate-shaped cover 16 and a body 21 . The cover 16 has a bearing hole 17 in the center thereof, which extends in the direction along the axis AL (see FIG. 5). The bearing hole 17 opens in the surface of the cover 16 facing the body 21 (upper side in FIG. 2).

[0036] As shown in Fig. 5, the body 21 has a cylindrical annular wall portion 22 that surrounds the axis line AL and extends in a direction along the axis line AL. A blocking portion 23 is formed at the end of the annular wall portion 22 opposite the cover 16 in the direction along the axis line AL (upper side in Fig. 5) with the end portion being blocked. The end of the annular wall portion 22 on the cover 16 side in the direction along the axis line AL is an open end 24. The open end 24 is blocked by the cover 16 attached to the body 21. The area of ​​the body 21 surrounded by the annular wall portion 22, the blocking portion 23, and the cover 16 constitutes a storage portion 25.

[0037] A bearing hole 26 is formed in the center of the closing portion 23, penetrating the closing portion 23 in the direction along the axis AL. As shown in FIG. 6, the annular wall portion 22 has an inlet 27 for the fluid FL into the storage portion 25. In addition, an outlet for the fluid FL from the storage portion 25 is formed at one or more locations on the annular wall portion 22. In this embodiment, a first outlet 31 is formed at a location in the annular wall portion 22 that is circumferentially separated from the inlet 27. In the following description, the term "circumferential direction" simply refers to the circumferential direction of the annular wall portion 22. Furthermore, a second outlet 35 is formed at a location in the annular wall portion 22 that is circumferentially separated from both the inlet 27 and the first outlet 31. The first outlet 31 and the second outlet 35 are adjacent to each other in the same circumferential direction in a part of the annular wall portion 22 in the circumferential direction, which is approximately half of the area in this embodiment. In the remaining area of ​​the annular wall portion 22 in the circumferential direction, only the inlet 27 is formed, and no outlet is formed. The inlet 27, the first outlet 31 and the second outlet 35 are circular or nearly circular in shape (see FIG. 5).

[0038] 1 and 6, a connecting pipe portion 28 is provided on the periphery of the inlet 27 of the annular wall portion 22, protruding outward in the radial direction of the annular wall portion 22. In the following description, the term "radial direction" simply refers to the radial direction of the annular wall portion 22. The connecting pipe portion 28 and the fluid supply source are connected by the common flow path 12 for the fluid FL.

[0039] A connecting pipe portion 32 is provided on the peripheral portion of the first outlet 31 in the annular wall portion 22, protruding outward in the radial direction in a direction different from the protruding direction of the connecting pipe portion 28. The first branch flow path 13 of the fluid FL is connected to the connecting pipe portion 32. The fluid FL flowing out from the first outlet 31 is sent to a destination of use of the fluid FL through the first branch flow path 13. A packing attachment portion 33 is formed in the annular wall portion 22 at a location on the inner side of the peripheral portion of the first outlet 31 in the radial direction. The packing attachment portion 33 has an inner bottom surface 33a at the boundary portion with the first outlet 31. The inner bottom surface 33a is formed by a plane that intersects with the central axis (not shown) of the first outlet 31 and the first branch flow path 13, and is perpendicular to the first outlet 31 in this embodiment.

[0040] A connecting pipe portion 36 is provided on the peripheral portion of the second outlet 35 in the annular wall portion 22, protruding outward in the radial direction in a direction different from the protruding direction of the connecting pipe portions 28, 32. The second branch flow path 14 of the fluid FL is connected to the connecting pipe portion 36. The fluid FL flowing out from the second outlet 35 is sent to a destination of use of the fluid FL through the second branch flow path 14. A packing mounting portion 37 is formed in the annular wall portion 22 at a location on the inner side of the peripheral portion of the second outlet 35 in the radial direction. The packing mounting portion 37 has an inner bottom surface 37a at the boundary portion with the second outlet 35. The inner bottom surface 37a is formed by a plane that intersects with the central axis (not shown) of the second outlet 35 and the second branch flow path 14, and is perpendicular in this embodiment. The packing mounting portion 37 is adjacent to the packing mounting portion 33 in the circumferential direction.

[0041] <Valve body 41> As shown in Figures 2, 3 and 6, the valve body 41 includes a valve body 42 constituting its framework and a shaft portion. The valve body 42 is cylindrical and extends along the axis AL, and is disposed (housed) in the housing portion 25. The valve body 42 includes a pair of disk-shaped end walls 43, 44 that are spaced apart from each other in the direction along the axis AL. The end walls 43, 44 are connected by a connecting portion 45 provided between a part of the outer periphery of the end wall 43 and a part of the outer periphery of the end wall 44. The connecting portion 45 has a part of the cylindrical outer periphery 46 of the valve body 42 as its own outer periphery.

[0042] In the valve main body 42, a portion between the end wall portions 43, 44 and different from the connecting portion 45 constitutes a movable flow path 47 that connects the inlet 27 with the first outlet 31 and the second outlet 35. The movable flow path 47 opens at an outer circumferential surface 46 of the valve main body 42.

[0043] The shaft portion includes shaft portions 48, 49 disposed on the axis AL. The shaft portion 48 protrudes from the center of the end wall portion 43 to one side in the direction along the axis AL (downward in Fig. 3). The shaft portion 49 protrudes from the center of the end wall portion 44 to the other side in the direction along the axis AL (upward in Figs. 2 and 3).

[0044] 5, the valve body 41 is rotatably supported by the shaft portion 48 in the bearing hole 17 of the cover 16. The shaft portion 49 is inserted into the bearing hole 26 of the closing portion 23. The valve body 41 is rotatably supported by the inner wall surface of the bearing hole 26 in the shaft portion 49. In this manner, the valve body 41 is rotatably supported by the housing 15 by both the shaft portions 48, 49.

[0045] The valve body 41 having the above-mentioned configuration is rotated by a motor (not shown), manual operation, etc. The rotation of the valve body 41 changes the rotation phase, and the communication state between the inlet 27 and the first outlet 31 and the second outlet 35 is changed.

[0046] In the rotation phase shown in Fig. 6, the valve body 42 (connecting portion 45) blocks a part of the first outlet 31 and a part of the hole 59 of the packing 55, and a part of the second outlet 35 and a part of the hole 59 of the packing 56. In this rotation phase, the common flow path 12 communicates with the first branch flow path 13 and the second branch flow path 14. In addition, in the rotation phase shown in Fig. 10, the valve body 42 (connecting portion 45) blocks the entire first outlet 31 and the entire hole 59 of the packing 55, and opens the entire second outlet 35 and the entire hole 59 of the packing 56. In this rotation phase, the common flow path 12 communicates with the second branch flow path 14. Although not shown, a rotation phase is also possible in which the valve body 42 (connecting portion 45) blocks the entire second outlet 35 and the entire hole 59 of the packing 56, and opens the entire first outlet 31 and the entire hole 59 of the packing 55. In this rotation phase, the common flow path 12 and the first branch flow path 13 are communicated with each other.

[0047] In addition, the rotational phases that the valve body 41 can take include rotational phases that adjust the respective opening degrees (degrees of opening) of the first outlet 31 and the hole 59 in the gasket 55, and rotational phases that adjust the respective opening degrees (degrees of opening) of the second outlet 35 and the hole 59 in the gasket 56.

[0048] <A pair of gaskets 55, 56> As shown in Figs. 3 and 6, both packings 55, 56 have the same configuration. Each packing 55, 56 is made of an elastic material such as rubber. One packing 55 is attached to the packing attachment portion 33. The packing 55 is located between the periphery of the first outlet 31 in the annular wall portion 22 and the outer circumferential surface 46 of the valve body portion 42. The other packing 56 is attached to the packing attachment portion 37. The packing 56 is located between the periphery of the second outlet 35 in the annular wall portion 22 and the outer circumferential surface 46 of the valve body portion 42. Both packings 55, 56 are adjacent to each other in the same circumferential direction in a part (approximately half) of the annular wall portion 22 in the circumferential direction, similar to the first outlet 31, the second outlet 35, and the packing attachment portions 33, 37.

[0049] Each of the packings 55, 56 includes a plate-shaped packing body 57 and a seal portion (not shown). The packing body 57 constitutes the framework of the packings 55, 56 and has a rectangular outer shape (see FIGS. 2 and 3).

[0050] An inner surface 58 of the packing body 57 of each of the packings 55, 56 in the radial direction is curved in a concave shape along the outer circumferential surface 46 of the valve body 42. Each packing body 57 has a circular hole 59 extending in the radial direction. Each hole 59 has an inner diameter (diameter) approximately equal to that of the first outlet 31 and the second outlet 35. The inner diameter (diameter) of the hole 59 of each packing 55, 56 is smaller than the dimension of the connecting portion 45 in the circumferential direction. Each hole 59 is formed to a size that can be blocked by the connecting portion 45. The hole 59 of the packing 55 faces the first outlet 31, and the hole 59 of the packing 56 faces the second outlet 35.

[0051] The seal portion of each of the packings 55, 56 protrudes radially inward from the periphery of the hole 59. Like the inner side surface 58, the seal portion is concavely curved along the outer circumferential surface 46, and is therefore capable of tightly contacting the outer circumferential surface 46.

[0052] <Shaft seal member 61> 2, 3, and 5, the shaft seal member 61 is formed in an annular shape from an elastic material such as rubber. An O-ring, an X-ring, or the like can be used as the shaft seal member 61. The shaft seal member 61 is disposed around the shaft portion 49, between the shaft portion 49 and the inner wall surface of the bearing hole 26 in the blocking portion 23. The shaft seal member 61 prevents the fluid FL in the accommodation portion 25 from leaking out of the rotary valve 10 through the gap between the shaft portion 49 and the inner wall surface of the bearing hole 26.

[0053] <Regarding the shape of the outer circumferential surface 46 of the valve main body 42> As shown in FIGS. 7 and 8, the rotary valve 10 of the present embodiment is characterized by the shape of the outer peripheral surface 46 of the valve body portion 42. In the conventional rotary valve 70 shown in FIG. 14, the outer peripheral surface 80 of the valve body portion 77 is constituted by a cylindrical surface having a single outer diameter (radius). In contrast, as shown in FIGS. 7 and 8, the outer peripheral surface 46 of the present embodiment has a large-diameter portion 51 and a small-diameter portion 52 located at different positions in the circumferential direction of the valve body portion 42. The large-diameter portion 51 and the small-diameter portion 52 are separated from each other in the circumferential direction of the valve body portion 42. The large-diameter portion 51 is constituted by the outer peripheral surface of the connecting portion 45. Both the large-diameter portion 51 and the small-diameter portion 52 are constituted by a part of a cylindrical surface centered on the axis AL.

[0054] As shown in FIG. 12, the large-diameter portion 51 and the small-diameter portion 52 are connected by a pair of flat portions 53 provided between them. Each flat portion 53 extends in the direction along the axis AL.

[0055] As shown in FIG. 4, the movable flow path 47 in the valve body portion 42 is not opened in the large-diameter portion 51. The movable flow path 47 is opened in the small-diameter portion 52 and the flat portion 53. <Regarding the dimensional relationships of each part> Here, as shown in FIG. 11, let the radius of the large-diameter portion 51 be radius A, and the radius of the small-diameter portion 52 be radius B. Let the portion where the thickness of the packings 55, 56 in the radial direction is the smallest be the minimum thickness portion 60, and the thickness at the minimum thickness portion 60 be the minimum thickness C. Let the distance between the axis AL and the portion where the minimum thickness portion 60 contacts the inner bottom surfaces 33a, 37a of the packing mounting portions 33, 37 be the mounting portion dimension D. The radius A, the radius B, the minimum thickness C, and the mounting portion dimension D satisfy the following (Equation 1) to (Equation 3).

[0056] B < A ··· (Equation 1) D - C < A ··· (Equation 2) D - C - B < C ··· (Equation 3) The above (Equation 2) means the following matters.

[0057] The radius A of the large diameter portion 51 is set to a size that causes interference with the packings 55, 56. In other words, the radius A is set to a size that causes the large diameter portion 51 to compress the packings 55, 56 and elastically deform them in the radial direction. Setting the radius A in this manner is necessary to seal between the annular wall portion 22 and the valve body portion 42 around the first outlet 31 and the second outlet 35.

[0058] Moreover, the left side of the above formula (3) is the dimension of the gap between the inner surface 58 of the packings 55, 56 and the small diameter portion 52 in the radial direction. In this embodiment, furthermore, the radius B, the minimum thickness C, and the mounting portion dimension D satisfy (Equation 4).

[0059] B≦DC (Formula 4) The above (Equation 4) means the following: When the radius B of the small diameter portion 52 is the same as DC, the small diameter portion 52 lightly contacts the inner surface 58 without causing any or almost no elastic deformation of the packings 55, 56.

[0060] When the radius B of the small diameter portion 52 is smaller than DC, the small diameter portion 52 is spaced apart from the inner surface 58 of the packings 55 and 56 . 12, a tangent line at a boundary between small diameter portion 52 and each flat portion 53 is defined as tangent line TL. In FIG. 12, only one of tangent lines TL is shown. Angle α is defined as an angle that each tangent line TL makes with flat portion 53. Angle α satisfies the following (Equation 5).

[0061] 170°≦α<180°...(Formula 5) It should be noted that if radius B were the same as radius A, angle α would be 180°. As described above, radius B is smaller than radius A, so angle α takes a value smaller than 180°.

[0062] <Rotational Phase of the Valve 41> The valve body 41 changes the rotational phase by rotating about the shafts 48 and 49. This rotational phase includes the following rotational phases.

[0063] 7, 8, 11, etc., a rotational phase in which the small diameter portion 52 faces all of the packings 55, 56. In this rotational phase, the small diameter portion 52 faces the entire packing 55 and the entire packing 56.

[0064] 9, 10, etc., a rotational phase in which the large diameter portion 51 faces only one of the packings 55, 56. That is, a rotational phase in which the large diameter portion 51 faces only the packing 55, or a rotational phase in which the large diameter portion 51 faces only the packing 56.

[0065] In this case, one end of the large diameter portion 51 in the circumferential direction is adjacent to one end of the packings 55, 56 in the circumferential direction. In addition, the other end of the large diameter portion 51 in the circumferential direction is adjacent to the other end of the packings 55, 56 in the circumferential direction.

[0066] 6 etc., a rotational phase in which the large diameter portion 51 faces a part of the packing 55 in the circumferential direction and faces a part of the packing 56 in the same circumferential direction. In other words, a rotational phase in which the large diameter portion 51 faces across a part of the packing 55 in the circumferential direction and a part of the packing 56 in the same circumferential direction.

[0067] Next, the operation of the present embodiment configured as above will be described. <Assembling the valve body 41> When assembling the valve body 41, as shown in Figures 3 and 4, the packing 55 is attached to the packing attachment portion 33, and the packing 56 is attached to the packing attachment portion 37. Separately from this, a shaft seal member 61 is placed over the shaft portion 49 of the valve body 41. Next, the valve body 42 is inserted into the annular wall portion 22, more precisely, into the housing portion 25 at a position different from the packings 55, 56. During this insertion process, the shaft portion 49 is inserted into the bearing hole 26 (see Figure 5).

[0068] The above insertion is performed in a state where the small diameter portion 52 is in a rotational phase opposed to the entire packing 55 and the entire packing 56, as shown in Figs. According to the above formula (1), radius B of small diameter portion 52 is smaller than radius A of large diameter portion 51. Therefore, during the above insertion, small diameter portion 52 does not or is unlikely to interfere with packings 55, 56. In the latter case, the degree of interference is smaller than when the radius of valve body 42 is the same as radius A of large diameter portion 51 over the entire circumference or when large diameter portion 51 faces at least one of packings 55, 56.

[0069] In particular, in this embodiment, radius B is equal to or smaller than the value obtained by subtracting minimum thickness C from mounting portion dimension D according to (Equation 4). Therefore, compared to a case in which radius B is larger than the value obtained by subtracting minimum thickness C from mounting portion dimension D, small diameter portion 52 is less likely to interfere with packings 55, 56 during the above insertion.

[0070] If a gap occurs between the small diameter portion 52 and the packings 55, 56 and the gap is excessively large, the packings 55, 56 may fall over in the gap when the valve body 42 is inserted into the annular wall portion 22. The valve body 42 must be inserted into the annular wall portion 22 so that the packings 55, 56 do not fall over, which reduces the efficiency of the insertion operation. There is also a risk that the valve body 42 may be inserted with the packings 55, 56 in a fallen state.

[0071] In this regard, due to the above (Equation 3), the gap generated between the small diameter portion 52 and the packings 55, 56 is smaller than the minimum thickness C. No excessive gap is generated between the small diameter portion 52 and the packings 55, 56. When the valve body 42 is inserted into the annular wall portion 22, the phenomenon in which the packings 55, 56 fall down in the gap is suppressed, improving the ease of insertion. Even if the packings 55, 56 fall down, they do not move significantly from the position before they fell down, which also makes the insertion easier.

[0072] After the valve main body 42 is inserted into the annular wall portion 22, the cover 16 is attached to the body 21 as shown in Fig. 5. During this attachment process, the shaft portion 48 is inserted into the bearing hole 17. The valve element 41 is rotatably supported in the housing 15 by the shaft portions 48, 49.

[0073] <Operation of rotary valve 10> When the rotary valve 10 is in operation, the valve body 41 rotates about the axis AL of the shaft portions 48, 49.

[0074] As shown in FIGS. 7, 8, 11, etc., in the rotational phase in which the small diameter portion 52 faces the packings 55, 56, the small diameter portion 52 does not interfere with the packings 55, 56, or if it does interfere, it is only slight.

[0075] Here, in the above formula 2, the radius A of the large diameter portion 51 is greater than the value obtained by subtracting the minimum thickness C from the mounting portion dimension D. Therefore, when the valve body 41 rotates from the above rotation phase in the direction shown by the arrow in Fig. 12 and changes to a rotation phase in which the large diameter portion 51 faces the packing 55, the boundary portion of the large diameter portion 51 with the flat portion 53 interferes with the packing 55, as shown in Fig. 12. When the valve body 41 rotates further, the large diameter portion 51 rides up onto the packing 55. The large diameter portion 51 compresses the packing 55 outward in the radial direction, causing the packing 55 to elastically deform in the radial direction.

[0076] When the large diameter portion 51 rides on the packing 55, the large diameter portion 51 is caught by resistance from the packing 55. The magnitude of this resistance varies depending on the angle α that the tangent TL at the boundary between the small diameter portion 52 and the flat portion 53 forms with respect to the flat portion 53. As the angle α increases, the large diameter portion 51 and the flat portion 53 are connected more gently, and the resistance that the large diameter portion 51 receives from the packing 55 decreases. In contrast, as shown in the comparative example of FIG. 13, as the angle α decreases, the large diameter portion 51 and the flat portion 53 have a pointed shape, and the resistance that the large diameter portion 51 receives from the packing 55 increases. Accordingly, the rotational torque required to rotate the valve body 41 increases.

[0077] In this regard, in the present embodiment in which the angle α is set to satisfy the above formula (5) as shown in Fig. 12, the large diameter portion 51 and the flat portion 53 are gradually connected. When the large diameter portion 51 rides up onto the packing 55, the resistance that the large diameter portion 51 receives from the packing 55 is reduced. The rotational torque required to rotate the valve body 41 is small.

[0078] In addition, when the large diameter portion 51 rides up onto the packing 56, the resistance that the large diameter portion 51 receives from the packing 56 is reduced in the same manner as described above. In this case as well, the rotational torque required to rotate the valve body 41 is small.

[0079] 9 and 10 show the state of the rotary valve 10 when the valve body 41 is rotated to a rotational phase where the large diameter portion 51 (connecting portion 45) faces only one of the packings 55. In this rotational phase, one end of the large diameter portion 51 in the circumferential direction is adjacent to one end of the packing 55 in the same circumferential direction. In addition, the other end of the large diameter portion 51 in the circumferential direction is adjacent to the other end of the packing 55 in the circumferential direction.

[0080] The movable flow path 47 is not opened to the large diameter portion 51 (connecting portion 45). Therefore, the first outlet 31 is closed by the large diameter portion 51 (connecting portion 45) via the packing 55.

[0081] At this time, the packing 55 located inside the first outlet 31 in the radial direction is compressed outward in the radial direction by the large diameter portion 51. The packing 55 is elastically deformed in the radial direction by the large diameter portion 51 (connecting portion 45).

[0082] Around the first outlet 31, the gap between the annular wall portion 22 and the valve body portion 42 (connecting portion 45) is sealed by the packing 55 elastically deformed as described above. More specifically, a seal is formed between the large diameter portion 51 and the packing 55, and a seal is formed between the packing 55 and the inner bottom surface 33a of the packing mounting portion 33.

[0083] In the above rotation phase, the small diameter portion 52 faces the packing 56. The movable flow path 47 opens into the small diameter portion 52. The second outlet 35 is in a state in which it is entirely open. Therefore, the fluid FL that flows from the common flow path 12 into the housing portion 25 through the inlet 27 flows through the movable flow path 47, i.e., after passing through the valve body 41, passes through the hole 59 of the packing 56 and the second outlet 35, and is discharged into the second branch flow path 14. The fluid FL does not pass through the hole 59 of the packing 55 and the first outlet 31, and is not discharged into the first branch flow path 13. In this way, the fluid FL is restricted from flowing out of the rotary valve 10 through the first outlet 31.

[0084] In addition, at this time, as described above, the large diameter portion 51 elastically deforms only the packing 55 at the location where sealing is required. Therefore, an extra load is less likely to act on the valve body 41 compared to the case where the large diameter portion 51 elastically deforms the packing 56 at the location where sealing is not required.

[0085] Although not shown, when the valve body 41 is rotated to a rotation phase in which the large diameter portion 51 (connecting portion 45) faces only the packing 56, the fluid FL passes through the hole 59 of the packing 55 and the first outlet 31 in the opposite direction to the above, and flows out to the first branch flow path 13. The fluid FL does not pass through the hole 59 of the packing 56 and the second outlet 35, and does not flow out to the second branch flow path 14.

[0086] Here, when the large diameter portion 51 elastically deforms the packing 55 or the packing 56 , a reaction force generated by the elastic deformation acts on the large diameter portion 51 . If the large diameter portion 51 were to face the entire packing 55 and the entire packing 56 at the same time, reaction forces from both packings 55, 56 would act on the large diameter portion 51. More specifically, a load equal to the combined reaction forces of both packings 55, 56 would act on the large diameter portion 51. This load would be directed toward the side of the axis AL where the packings 55, 56 are not located. The load is transmitted as an unbalanced load from one direction in the radial direction of the valve body 41 to the shaft seal member 61 via the valve body 42 and the shaft portion 49 in FIG. 5.

[0087] In this regard, in the two rotation phases described above, the large diameter portion 51 faces only the packing 55 or only the packing 56. Of the packings 55 and 56, the one that the large diameter portion 51 does not face does not exert a reaction force on the large diameter portion 51. Therefore, the offset load acting on the shaft seal member 61 is reduced.

[0088] 6 shows the state of the rotary valve 10 when the large diameter portion 51 (connecting portion 45) of the valve body 42 faces a part of the packing 55 and a part of the packing 56 while straddling them. Of the holes 59 of the packing 55, approximately half on the side closer to the packing 56 is blocked, and approximately half on the side farther away is open. The same is true for the first outlet 31. Of the holes 59 of the packing 56, approximately half on the side closer to the packing 55 is blocked, and approximately half on the side farther away is open. The same is true for the second outlet 35.

[0089] In this state, the fluid FL that has flowed through the common flow path 12 flows into the storage section 25 through the inlet 27. A part of this fluid FL flows through the movable flow path 47, then passes through the hole 59 of the packing 55 and each opening of the first outlet 31, and is discharged into the first branch flow path 13. The remaining part of the fluid FL flows through the movable flow path 47, then passes through the hole 59 of the packing 56 and each opening of the second outlet 35, and is discharged into the second branch flow path 14.

[0090] However, the opening area of ​​the hole 59 in the packing 55 is smaller than when the hole 59 is entirely opened. The same applies to the opening area of ​​the first outlet 31. Therefore, the flow rate of the fluid FL flowing through the hole 59 of the packing 55 and the first outlet 31 to the first branch flow path 13 is smaller than when the hole 59 of the packing 55 is entirely opened and the first outlet 31 is entirely opened. The same applies to the flow rate of the fluid FL flowing through the hole 59 of the packing 56 and the second outlet 35 to the second branch flow path 14.

[0091] At this time, the large diameter portion 51 (connecting portion 45) faces a part of the packing 55 and a part of the packing 56 while spanning them. Therefore, the offset load acting on the shaft seal member 61 is smaller than when the large diameter portion 51 faces the entire packing 55 and the entire packing 56 at the same time.

[0092] Next, the effects of this embodiment will be described. (1) As shown in FIG. 11, in this embodiment, the outer circumferential surface 46 of the valve body 42 includes a large diameter portion 51 having a radius A and a small diameter portion 52 having a radius B smaller than the radius A.

[0093] Therefore, when the valve body 42 is inserted into the annular wall 22 in a rotational phase in which the small diameter portion 52 faces both packings 55, 56, interference between the small diameter portion 52 and the packings 55, 56 can be avoided or suppressed. In the latter case, the degree of interference can be made smaller than when the radius of the valve body 42 is the same as the radius A of the large diameter portion 51 over the entire circumference, or when the large diameter portion 51 faces at least one of the packings 55, 56. This makes it easier to insert the valve body 42 into the annular wall 22. This improves the ease of assembly of the valve body 41.

[0094] (2) In particular, in this embodiment, the radius B, the minimum thickness C, and the mounting portion dimension D are set to values ​​that satisfy (Equation 4). Therefore, compared to when radius B is greater than the mounting portion dimension D minus minimum thickness C, small diameter portion 52 is less likely to interfere with packings 55, 56 during the above insertion. Valve body 42 can be inserted even more easily into annular wall portion 22.

[0095] Therefore, unlike the conventional rotary valve 70, when assembling the valve body 41, it is not necessary to use a jig for elastically deforming the packings 55, 56. This can prevent the increase in production equipment required for using a jig. In addition, it can prevent an increase in the number of assembly steps required for using a jig.

[0096] Also, unlike the conventional rotary valve 70, by forcefully inserting the valve main body 42 into the annular wall portion 22 without using a jig, it is not necessary to expand the space in which the valve main body 42 is housed. This makes it possible to prevent the packings 55, 56 from being damaged or the seal portions of the packings 55, 56 from being caught between the body 21 and the valve main body 42, etc., due to the forceful insertion of the valve main body 42.

[0097] (3) As shown in Fig. 11, in this embodiment, the radius B, the minimum thickness C, and the mounting portion dimension D satisfy the above formula 3. The gap between the small diameter portion 52 and the packings 55, 56 is made smaller than the minimum thickness C. Therefore, when the valve main body 42 is inserted into the annular wall portion 22, the packings 55, 56 can be prevented from falling in the gap. Even if the packings 55, 56 fall, they do not move significantly from their positions before they fall. Therefore, the workability of inserting the valve main body 42 can be further improved.

[0098] (4) In this embodiment, as shown in the above (Equation 2), the radius A is set to be larger than the value obtained by subtracting the minimum thickness C from the mounting portion dimension D. Therefore, by adjusting the rotational phase of the valve body 41 to a rotational phase in which the large diameter portion 51 faces the packings 55, 56, the packings 55, 56 can be compressed radially outward and elastically deformed in the same radial direction. Around the first outlet 31 and the second outlet 35, the gap between the annular wall portion 22 and the valve body portion 42 can be sealed.

[0099] 10 , when the large diameter portion 51 faces the packing 55, the first outlet 31 can be entirely blocked by the large diameter portion 51 via the packing 55. The fluid FL in the storage portion 25 can be restricted from flowing out of the rotary valve 10 through the blocked first outlet 31.

[0100] Although not shown, when the large diameter portion 51 faces the packing 56, the second outlet 35 can be entirely blocked by the large diameter portion 51 via the packing 56. This can restrict the fluid FL in the accommodating portion 25 from flowing out of the rotary valve 10 through the blocked second outlet 35.

[0101] (5) As shown in Figures 9 and 10, in this embodiment, the rotational phase of the valve body 41 includes a rotational phase in which the large diameter portion 51 faces only one of the packings 55, 56. Therefore, the rotational torque required to rotate the valve body 41 can be reduced compared to a case in which the large diameter portion 51 elastically deforms the packings 55, 56 at locations that do not require sealing. As a result, it is possible to reduce the load applied to the mechanism for rotating the valve body 41, extend the product life of the rotary valve 10, and reduce the size of the actuator.

[0102] (6) As shown in FIG. 12, in this embodiment, the angle α is set to a value that satisfies the above formula (5). Therefore, when the large diameter portion 51 rides up on the packing 55 as the valve body 41 rotates, the resistance that the large diameter portion 51 receives from the packing 55 can be reduced. The same is true when the large diameter portion 51 rides up on the packing 56. Therefore, the rotational torque required to rotate the valve body 41 can be reduced. Therefore, in this respect as well, as in (5) above, it is possible to reduce the load applied to the mechanism for rotating the valve body 41, extend the product life of the rotary valve 10, and reduce the size of the actuator.

[0103] 2 to 5, in this embodiment, the combination of the packing mounting portion 33 and the packing 55 and the combination of the packing mounting portion 37 and the packing 56 are adjacent to each other in the same circumferential direction in a partial region of the annular wall portion 22 in the circumferential direction. An annular shaft seal member 61 is disposed between the shaft portion 49 and the inner wall surface of the bearing hole 26 in the housing 15 (closure portion 23).

[0104] In such a rotary valve 10, the rotational phase of the valve body 41 includes a rotational phase in which the large diameter portion 51 faces only one of the packings 55, 56, as shown in FIGS.

[0105] Therefore, the packings 55, 56 that do not face the large diameter portion 51 do not exert a reaction force on the large diameter portion 51, and the offset load acting on the shaft seal member 61 can be reduced.

[0106] The above-mentioned effect can be obtained similarly when the large diameter portion 51 (connecting portion 45) faces a part of the packing 55 and a part of the packing 56 while straddling them, as shown in FIGS. The above embodiment can also be implemented as modified examples as follows: The above embodiment and the following modified examples can be implemented in combination with each other within a range that does not cause technical contradiction.

[0107] <Matters regarding Housing 15> The positions of the blocking portion 23 and the cover 16 in the direction along the axis AL may be changed so as to be inverse to those in the above embodiment. For example, in FIG. 5, the cover 16 may be disposed on the upper side of the annular wall portion 22, and the blocking portion 23 may be formed on the lower side of the annular wall portion 22.

[0108] The inlet 27 may be formed in a location in the housing 15 other than the annular wall portion 22, for example, in the closing portion 23. In this case, the fluid FL flows into the containing portion 25 in a direction along the axis AL.

[0109] The outflow port may be provided at only one location on the annular wall portion 22. The same applies to the packing attachment portion. In this case, by attaching the packing to the packing attachment portion, the packing is disposed between the periphery of the outflow port and the outer peripheral surface 46 of the valve body portion 42.

[0110] When assembling the valve disc 41, the valve body 42 is inserted into the annular wall portion 22 with the small diameter portion 52 in a rotational phase facing the packing. The radius B of the small diameter portion 52 is smaller than the radius A of the large diameter portion 51. Therefore, interference between the valve body 42 and the packing is less likely to occur and the valve body 42 is easier to insert into the annular wall portion 22 than when the radius of the valve body 42 is the same as the radius A of the large diameter portion 51 over the entire circumference.

[0111] When the rotary valve 10 is operated, the valve body 41 rotates about the shafts 48, 49. When this rotation brings the large diameter portion 51 into opposition to the packing, the packing is elastically deformed by the large diameter portion 51, and the gap between the annular wall portion 22 and the valve body portion 42 is sealed around the outlet. The outlet is blocked by the large diameter portion 51 via the packing. The fluid FL in the accommodation portion 25 is restricted from flowing out of the rotary valve 10 through the outlet. Because there is only one outlet, the flow of the fluid FL is blocked by the rotary valve 10.

[0112] The outflow ports may be provided at three or more locations in the circumferential direction of the annular wall portion 22. The same applies to the packing mounting portions. In this case, each packing is mounted to the corresponding packing mounting portion, so that each packing is disposed between the periphery of each outflow port and the outer circumferential surface 46 of the valve body portion 42.

[0113] When assembling the valve disc 41, the valve body 42 is inserted into the annular wall portion 22 with the small diameter portion 52 in a rotational phase facing all of the packings. The radius B of the small diameter portion 52 is smaller than the radius A of the large diameter portion 51. Therefore, interference is less likely to occur between the valve body 42 and the packings and the valve body 42 is easier to insert into the annular wall portion 22 than when the radius of the valve body 42 is the same as the radius A of the large diameter portion 51 over the entire circumference.

[0114] When the rotary valve 10 is in operation, the valve body 41 rotates about the shafts 48, 49. When the rotational phase of the valve body 41 reaches a rotational phase in which the large diameter portion 51 faces at least one packing, the packing is elastically deformed by the large diameter portion 51. Around the outflow port on the outer side of the packing in the radial direction, the gap between the annular wall portion 22 and the valve body portion 42 is sealed. The outflow port is blocked by the large diameter portion 51 via the packing. The fluid FL in the accommodation portion 25 is restricted from flowing out of the rotary valve 10 from the outflow port.

[0115] In the above rotation phase, if there is one of the plurality of outlets to which the small diameter portion 52 faces, the fluid FL flows out of the rotary valve 10 from that outlet. In contrast, when the large diameter portion 51 faces all of the outlets in the above rotation phase, all of the outlets are blocked. The fluid FL in the accommodation portion 25 is restricted from flowing out of the rotary valve 10 through all of the outlets. The flow of the fluid FL is blocked by the rotary valve 10.

[0116] When the combinations of the outlet, the packing mounting portion, and the packing are provided at three or more locations in the circumferential direction of the annular wall portion 22 as described above, the following concerns may arise depending on the locations of the combinations: For example, this may occur when all the combinations are arranged adjacent to each other in the same circumferential direction in a partial area of ​​the annular wall portion 22 in the circumferential direction.

[0117] When the large diameter portion 51 faces all the packings at the same time, reaction forces from all the packings act on the large diameter portion 51. A load equal to the combined reaction forces of the packings acts on the large diameter portion 51. This load is directed toward the side of the axis AL where no packings are located. The load is transmitted as an unbalanced load from one direction in the radial direction of the valve body 41 to the shaft seal member 61 via the valve body 42 and the shaft portion 49.

[0118] Therefore, the large diameter portion 51 is designed not to face all the packings at the same time. In this way, no reaction force is applied to the large diameter portion 51 from the packings that the large diameter portion 51 does not face. Therefore, as in the above (7), the effect of reducing the unbalanced load acting on the shaft seal member 61 is obtained.

[0119] In the above embodiment in which the combination of the outlet, the packing mounting portion, and the packing is provided at two locations on the annular wall portion 22, the large diameter portion 51 may simultaneously face the entire packing 55 and the entire packing 56 as the valve body 41 rotates. In this case, both the first outlet 31 and the second outlet 35 are blocked by the large diameter portion 51 via the packings 55, 56, and the fluid FL in the accommodation portion 25 is restricted from flowing out to the outside of the rotary valve 10 through the first outlet 31 and the second outlet 35. The flow of the fluid FL is blocked by the rotary valve 10.

[0120] <Matters related to valve body 41> The shape of the movable flow passage 47 in the valve body 42 may be changed to a shape different from that in the above embodiment.

[0121] The opening shape of the movable flow passage 47 on the outer circumferential surface 46 of the valve body 42 may be changed to a shape different from that in the above embodiment. The radius B of the small diameter portion 52 may be set to a size that contacts or lightly presses into the seal portions of the packings 55, 56, provided that the radius B is smaller than the radius A of the large diameter portion 51. In this case as well, there is less interference between the valve body 42 and the packings 55, 56, compared to when the radius of the valve body 42 is the same as the radius A of the large diameter portion 51 over the entire circumference. This makes it easier to insert the valve body 42 into the annular wall portion 22.

[0122] The shaft portion of the valve body 41 may be formed by one of the shaft portions 48 and 49 . The angle α that the tangent line TL makes with the flat surface portion 53 may be set to a value smaller than 170°.

[0123] <Matters regarding packings 55 and 56> The outer shape of the packing body 57 of the packings 55, 56 may be changed to a shape other than rectangular.

[0124] The packing body 57 of the packings 55, 56 may be formed in a shape other than a plate shape. The shape of the holes 59 in the packings 55, 56 may be changed to a shape other than circular.

[0125] <Other> The rotary valve 10 described above can also be applied to a rotary valve provided in a flow path through which a liquid other than water flows as the fluid FL, or to a rotary valve provided in a flow path through which gas flows instead of a liquid as the fluid FL. [Explanation of symbols]

[0126] 10...Rotary valve 15. Housing 22...Annular wall portion 26...Bearing hole 27…Inlet 31...1st outlet (outlet) 33,37…Packing attachment part 33a, 37a…Inner bottom surface 35…Second outlet (outlet) 41...Valve body 42...Valve body 46...Outer surface 48,49…Shaft 51…Large diameter section 52…Small diameter part 53...Plane part 55,56…Packing 58…Inner surface 60: Minimum thickness 61...Shaft seal member A,B…Radius AL…Axis line C: Minimum thickness D…Attachment dimensions FL…Fluid TL…Tangent line α…Angle

Claims

1. The valve includes a housing having a fluid inlet and a fluid outlet, and a valve body. the housing includes an annular wall portion that extends along the axis while surrounding the axis and has the outflow port at one or more locations in a circumferential direction of the annular wall portion; The valve body includes a cylindrical valve body portion accommodated in the annular wall portion, a packing mounting portion is formed at a radially inward portion of the annular wall portion with respect to a peripheral edge portion of each of the outlet ports, A packing is attached to the packing attachment portion, and the inner surface in the radial direction is curved concavely along the outer circumferential surface of the valve body, A rotary valve in which a rotation phase changes with rotation of the valve body around the axis, thereby changing a communication state between the inlet and the outlet, The outer circumferential surface of the valve body includes a large diameter portion that seals between the annular wall portion and the valve body around the outlet by elastically deforming the packing in the radial direction, and a small diameter portion that is located at a different position in the circumferential direction of the valve body relative to the large diameter portion, the rotational phase includes a rotational phase in which the small diameter portion faces all of the packings, When the radius of the large diameter portion is radius A, the radius of the small diameter portion is radius B, the portion where the thickness of the packing in the radial direction is smallest is a minimum thickness portion, the thickness at the minimum thickness portion is minimum thickness C, and the distance between the axis and a portion of the inner bottom surface of the packing mounting portion where the minimum thickness portion comes into contact is a mounting portion dimension D, the radius A, the radius B, the minimum thickness C, and the mounting portion dimension D satisfy (Equation 1) to (Equation 3). B<A...(Formula 1) DC<A...(Formula 2) DCB<C... (Formula 3) Rotary valve.

2. The radius B, the minimum thickness C, and the mounting portion dimension D satisfy (Equation 4). B≦DC...(Formula 4) 2. The rotary valve according to claim 1.

3. A combination of the outlet port and the packing mounting portion is formed at two locations in the circumferential direction of the annular wall portion, 3. The rotary valve according to claim 2, wherein the rotational phase includes a rotational phase in which the large diameter portion faces only one of the packings.

4. the large diameter portion and the small diameter portion are connected by a pair of flat portions provided between the large diameter portion and the small diameter portion, The angle α that the tangent at the boundary between the small diameter portion and each flat portion forms with the flat portion satisfies (Equation 5). 170°≦α<180°...(Formula 5) 3. A rotary valve as claimed in claim 2.

5. combinations of the two packing mounting portions and the packings mounted on the respective packing mounting portions are adjacent to each other in the circumferential direction in a partial region of the annular wall portion in the circumferential direction, The valve body includes a shaft portion extending along the axis line on the axis line, The housing is formed with a bearing hole through which the shaft portion is inserted, 4. The rotary valve according to claim 3, further comprising an annular shaft seal member disposed around the shaft portion and between the shaft portion and an inner wall surface of the bearing hole.

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