Sealing element of rotary valve

Abstract

The invention provides a seal for a rotary valve. The seal is disposed between a rotor and a housing that accommodates the rotor. A seal for a rotary valve is provided with a main body part extending in the circumferential direction of a rotor and in the axial direction of the rotor, and a rib part protruding from the main body part in the radial direction of the rotor, the rib part has a circumferential rib part extending in the circumferential direction, and the circumferential rib part includes an inner circumferential rib part protruding inward in the radial direction and an outer circumferential rib part protruding outward in the radial direction. The number of the inner circumferential ribs is smaller than the number of the outer circumferential ribs.

Description

Technical Field

[0001] The present invention relates to a seal for a rotary valve. Background Art

[0002] Sealing members for valves that control the flow path through which a fluid flows have been disclosed (for example, Patent Document 1 and Patent Document 2). The valve disclosed in Patent Document 1 (in Patent Document 1, a flow path switching valve) includes a valve body having a valve chamber, a sealing member housed in the valve chamber, a rotating portion housed in the valve chamber and having a valve element with a circular valve opening formed therein, and a valve drive portion that is a drive source for rotating the rotating portion. The sealing member is disposed on the outer side in the valve radial direction with respect to the valve element and is formed in a ring shape to surround the valve element.

[0003] The valve disclosed in Patent Document 2 (in Patent Document 2, a rotary slide valve) includes a housing, a rotary slider, and a sealing element disposed between the rotary slider and the housing. The sealing element includes a first raised portion and a second raised portion extending in a first radial direction, and a third raised portion extending in a second radial direction. Patent Document

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2017-207157 Patent Document 2: German Patent Application Publication No. 102022200540 Specification Summary of the Invention

[0005] The sealing member disclosed in Patent Document 1 has a plurality of sealing portions having an annular shape around the periphery of the valve opening. When the valve body rotates, the surface pressure received by the sealing portion may increase, and the sliding resistance may become large. In addition, even in the sealing element disclosed in Patent Document 2, if the slope of the third raised portion extending in the second radial direction is steep, when the rotary slider rotates, the surface pressure received by the sealing element may increase, and the sliding resistance may become large.

[0006] The present invention has been completed in view of the above technical problems, and an object thereof is to provide a seal for a rotary valve that can reduce sliding resistance.

[0007] The seal of the rotary valve involved in the present invention is characterized in the following aspects: It is a seal of a rotary valve disposed between a rotor and a housing that houses the rotor. It includes a main body portion extending along the circumferential direction of the rotor and the axial direction of the rotor, and rib portions protruding radially from the main body portion toward the rotor. The rib portions have circumferential rib portions extending along the circumferential direction. The circumferential rib portions include inner circumferential rib portions protruding inward in the radial direction and outer circumferential rib portions protruding outward in the radial direction. The number of the inner circumferential rib portions is less than the number of the outer circumferential rib portions. The inclination of the inner circumferential rib portion between the base end of the inner circumferential rib portion and the apex of the inner circumferential rib portion is gentler than the inclination of the outer circumferential rib portion between the base end of the outer circumferential rib portion and the apex of the outer circumferential rib portion.

[0008] According to this structure, since the number of the inner circumferential rib portions that are in sliding contact with the rotor is less than the number of the outer circumferential rib portions, the sliding resistance of the rotor can be reduced. In addition, since the number of the inner circumferential rib portions that are in sliding contact with the rotor is less than the number of the outer circumferential rib portions that are in sliding contact with the housing, the frictional resistance between the housing and the seal becomes larger, thereby preventing malfunction such as the seal shifting with the rotation of the rotor. In addition, according to this structure, since the inclination of the inner circumferential rib portion is gentler than that of the outer circumferential rib portion, the collapse of the inner circumferential rib portion can be suppressed by the rotation of the rotor, and the durability of the seal can be improved. In addition, since the inclination of the outer circumferential rib portion is steeper than that of the inner circumferential rib portion, the reaction force of the seal on the rotor can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A longitudinal sectional view showing the structure of the rotary valve according to the embodiment. Figure 2 A view showing the first position of the rotor according to the embodiment. Figure 3 A perspective view showing the rotor according to the embodiment. Figure 4 A perspective view showing the rotor when viewed from an angle different from Figure 3 that. Figure 5 A perspective view showing the seal according to the embodiment. Figure 6 A perspective view showing the seal when viewed from an angle different from Figure 5 that. Figure 7 A view showing the structure of the circumferential rib portion according to the embodiment. Figure 8 A view showing the structure of the axial rib portion according to the embodiment. ​​​​​​​​Figure 9 Schematic diagram showing the positional relationship of the vertices of the ribs involved in the embodiment. Figure 10 Diagram showing the second position of the rotor involved in the embodiment. Figure 11 Diagram showing the third position of the rotor involved in the embodiment. Figure 12 Diagram showing the fourth position of the rotor involved in the embodiment. DETAILED DESCRIPTION

[0010] Hereinafter, a rotary valve including a seal according to an embodiment of the present invention will be described with reference to the accompanying Figure 1 drawings. However, the present invention is not limited to the following embodiments, and various modifications can be made without departing from the gist thereof.

[0011] [Basic Structure] Figure 1 A cross-section (longitudinal section) along the axis X of the rotary valve 100 is shown. In the present embodiment, the rotary valve 100 is a five-way valve for controlling the flow of a fluid to a cooling target device such as a battery or an electric motor mounted on a vehicle such as an automobile. The fluid is cooling water such as long-life coolant (LLC). It should be noted that the fluid may also be an insulating oil such as a paraffin-based oil, a refrigerant such as hydrofluorocarbons (HFCs), or hydrofluoroolefins (HFOs).

[0012] As Figure 1 shown, the rotary valve 100 includes a housing 1, a rotor 2 housed in the housing 1, a bushing 3 that rotatably supports the rotor 2, a seal 4 disposed between the housing 1 and the rotor 2, and an actuator 5 connected to the rotor 2. The actuator 5 transmits a rotational force to the rotor 2. The rotor 2 rotates about the axis X by the rotational force from the actuator 5. By the rotation of the rotor 2, the flow of the fluid is controlled.

[0013] Hereinafter, the direction along the axis X of the rotor 2 will be referred to as the "axis direction DX", the circumferential direction DC of the rotor 2 will be simply referred to as the "circumferential direction DC", and the radial direction DR of the rotor 2 will be simply referred to as the "radial direction DR". In addition, the direction from the outside to the inside of the radial direction DR will be referred to as the "radial inner direction DR1", and the opposite direction will be referred to as the "radial outer direction DR2".

[0014] [Housing] Figure 2 is a transverse cross-sectional view showing the rotary valve 100. It should be noted that Figure 2 is a view of the rotary valve 100 as viewed from the actuator 5 side. As Figure 2 ​​​​As shown, the housing 1 has a housing wall portion 11 that divides the space for housing the rotor 2.

[0015] When viewed in the axial direction DX, the housing wall portion 11 is circular. A plurality of ports 12 are formed in the housing wall portion 11 along the circumferential direction DC. In the present embodiment, four ports 12 are formed in the housing wall portion 11 along the circumferential direction DC, and the four ports 12 penetrate the housing wall portion 11 in the radial direction DR. Hereinafter, the four ports 12 will be referred to as "first port 121", "second port 122", "third port 123", and "fourth port 124" respectively.

[0016] In addition, a fifth port 125 is formed in the lower part (bottom wall) of the housing wall portion 11. The first port 121, the second port 122, the third port 123, the fourth port 124, and the fifth port 125 are each connected to a different external flow path. The external flow path is connected to, for example, a battery, a motor, etc.

[0017] [Rotor] Figure 3 And Figure 4 To show a perspective view of the rotor 2. As Figure 3 And Figure 4 shown, the rotor 2 includes a shaft portion 20 coaxial with the axis X, and a cylindrical valve portion 21 that can rotate integrally with the shaft portion 20. The rotor 2 is made of a material such as resin, and the shaft portion 20 and the valve portion 21 are formed integrally.

[0018] As Figure 1 And Figure 2 shown, a first valve flow path L1 and a second valve flow path L2 through which fluid flows in the rotor 2 in a specified posture are formed in the valve portion 21. The first valve flow path L1 is formed in a substantially V shape that bends near the axis X when viewed in the direction of the axial direction DX (refer to Figure 2 ). The second valve flow path L2 is composed of a portion cut out in a fan shape centered on the axis X (in a three-dimensional space, it is a truncated cone shape) (refer to Figure 3 ).

[0019] [Seal] As Figure 2 shown, the seal 4 is disposed between the housing 1 and the rotor 2 over substantially the entire circumference in the circumferential direction DC of the rotor 2. The seal 4 is composed of a member that can undergo elastic deformation, and prevents fluid from flowing into other flow paths by being compressed by the housing 1 and the rotor 2. The seal 4 is made of rubber such as nitrile rubber (NBR), fluororubber (FKM), and polyurethane rubber (U).

[0020] As Figure 2 , Figure 5 And Figure 6As shown, the seal 4 has a cylindrical seal main body portion 41 (an example of the main body portion). It should be noted that in Figure 5 and Figure 6 a part on the circumferential direction DC of the seal 4 is cut off.

[0021] As Figure 2 shown, in a state where the seal 4 is disposed between the outer shell 1 and the rotor 2, the seal main body portion 41 extends along the circumferential direction DC and the axial direction DX. The seal main body portion 41 includes a protrusion portion 411 (an example of a rotation prevention portion) that prevents the seal 4 from rotating relative to the outer shell 1. The protrusion portion 411 protrudes outward in the radial direction DR from both end portions on the circumferential direction DC of the seal main body portion 41 in a state where the seal 4 is disposed between the outer shell 1 and the rotor 2, and is received in the recess 111 provided in the outer shell wall portion 11. Thus, on the circumferential direction DC, the protrusion portion 411 faces (contacts) the outer shell wall portion 11 of the outer shell 1, thereby preventing the seal 4 from rotating relative to the outer shell 1.

[0022] In addition, as Figure 5 shown, a seal opening 41h (an example of an opening) through which fluid passes is formed in the seal main body portion 41. Specifically, four seal openings 41h are formed along the circumferential direction DC in the seal main body portion 41, and the four seal openings 41h are formed at positions corresponding to the four ports 12 of the outer shell 1 described with reference to Figure 2 . Hereinafter, the four seal openings 41h will be respectively referred to as "first seal opening h1", "second seal opening h2", "third seal opening h3", and "fourth seal opening h4".

[0023] In the present embodiment, the dimensions of the first seal opening h1 and the fourth seal opening h4 on the circumferential direction DC are formed to be larger than the dimensions of the second seal opening h2 and the third seal opening h3 on the circumferential direction DC. Thereby, it is possible to cause the fluid flowing in from different ports 12 (for example, the second port 122 and the third port 123) to flow out to the same port 12 (for example, the first port 121) (refer to Figure 2 and Figure 10 ). Or, it is possible to cause the fluid flowing in from the same port 12 (for example, the third port 123) to flow into different ports 12 (for example, the first port 121 or the fourth port 124) (refer to Figure 10 and Figure 12 ).

[0024] [Circumferential rib portion] In addition, as Figure 5 shown, the seal 4 includes a rib portion 42 that protrudes in the radial direction DR from the seal main body portion 41. As Figure 6As shown, the rib 42 has a circumferential rib 43 that extends (is continuously provided) along the circumferential direction DC. The circumferential rib 43 includes an inner circumferential rib 44 provided in the radially inner direction DR1 of the sealing main body 41 and protruding in the radially inner direction DR1, and an outer circumferential rib 45 provided in the radially outer direction DR2 of the sealing main body 41 and protruding in the radially outer direction DR2. The number of the inner circumferential ribs 44 is less than the number of the outer circumferential ribs 45. In the present embodiment, two inner circumferential ribs 44 and four outer circumferential ribs 45 are provided on the sealing main body 41.

[0025] The circumferential rib 43 is composed of two rib groups 43g provided at both ends of the sealing main body 41 in the axial direction DX. The rib groups 43g are provided so as to sandwich four sealing openings 41h in the axial direction DX. In the present embodiment, the rib group 43g includes two outer circumferential ribs 45 and one inner circumferential rib 44 provided between the two outer circumferential ribs 45. Hereinafter, the outer circumferential rib 45 located on the end side of the sealing main body 41 in the axial direction DX among the two outer circumferential ribs 45 included in one rib group 43g will be referred to as the "first outer circumferential rib 45a", and the outer circumferential rib 45 located on the central side of the sealing main body 41 in the axial direction DX will be referred to as the "second outer circumferential rib 45b".

[0026] Figure 7 It is a sectional view showing the sealing member 4 cut along the axial direction DX. As Figure 7 shown, in the inner circumferential rib 44, a sliding property improvement layer LY for improving the sliding property is provided on the surface. The sliding property improvement layer LY is formed by coating a material having a friction coefficient smaller than that of the outer circumferential rib 45 (the material of the rib 42). The sliding property improvement layer LY is made of materials such as polyoxymethylene (POM), polyamide (PA), and polytetrafluoroethylene (PTFE).

[0027] In addition, as Figure 7 shown, the inclination of the inner circumferential rib inclined portion 44k of the inner circumferential rib 44 is gentler than the inclination of the outer circumferential rib inclined portion 45k of the outer circumferential rib 45. In the present embodiment, the vicinity of the inner circumferential rib vertex 44t and the vicinity of the outer circumferential rib vertex 45t have an arc shape in cross-section, and the radius of curvature of the arc constituting the vicinity of the inner circumferential rib vertex 44t is larger than the radius of curvature of the arc constituting the vicinity of the outer circumferential rib vertex 45t. It should be noted that the inner circumferential rib inclined portion 44k is the portion between the inner circumferential rib base end 44p as the base end of the inner circumferential rib 44 and the inner circumferential rib vertex 44t as the vertex of the inner circumferential rib 44, and the outer circumferential rib inclined portion 45k is the portion between the outer circumferential rib base end 45p as the base end of the outer circumferential rib 45 and the outer circumferential rib vertex 45t as the vertex of the outer circumferential rib 45.

[0028] [Axial rib] In addition, as Figure 6 shown, the rib 42 further has an axial rib 46 extending (continuously provided) along the axial direction DX. The axial rib 46 includes an inner axial rib 47 provided in the radially inner direction DR1 of the sealing main body 41 and protruding toward the radially inner direction DR1, and an outer axial rib 48 provided in the radially outer direction DR2 of the sealing main body 41 and protruding toward the radially outer direction DR2. It should be noted that hereinafter, the inner circumferential rib 44 and the inner axial rib 47 are sometimes collectively referred to as the "inner ribs", and the outer circumferential rib 45 and the outer axial rib 48 are sometimes collectively referred to as the "outer ribs".

[0029] Figure 8 is a cross-sectional schematic diagram of a part of the seal 4 cut along a direction orthogonal to the axial direction DX. As Figure 8 shown, similar to the inner circumferential rib 44 described with reference to Figure 7 , a sliding property improving layer LY is also provided on the surface of the inner axial rib 47. That is, in the inner ribs, a sliding property improving layer LY is provided on the surface. In addition, the shape of the axial rib 46 is also substantially similar to the shape of the circumferential rib 43. Specifically, the inclination of the inner axial rib inclined portion 47k of the inner axial rib 47 is gentler than the inclination of the outer axial rib inclined portion 48k of the outer axial rib 48. It should be noted that the inner axial rib inclined portion 47k is the portion between the inner axial rib base end 47p serving as the base end of the inner axial rib 47 and the inner axial rib apex 47t serving as the apex of the inner axial rib 47, and the outer axial rib inclined portion 48k is the portion between the outer axial rib base end 48p serving as the base end of the outer axial rib 48 and the outer axial rib apex 48t serving as the apex of the outer axial rib 48.

[0030] As Figure 6 shown, in the present embodiment, the inner axial rib 47 and the outer axial rib 48 are provided at each of the seal openings sandwiching four seal openings 41h in the circumferential direction DC. The rib 42 (circumferential rib 43 and axial rib 46) is provided to surround the seal opening 41h. Specifically, the end portion of the inner axial rib 47 in the axial direction DX is connected to the inner circumferential rib 44, and the end portion of the outer axial rib 48 in the axial direction DX is connected to the second outer circumferential rib 45b. In the present embodiment, when observed along the radial direction DR, the first connection portion C1 between the inner axial rib 47 and the inner circumferential rib 44 and the second connection portion C2 between the outer axial rib 48 and the second outer circumferential rib 45b have a round shape with roundness.

[0031] Figure 9 is a schematic diagram showing the positional relationship of the vertices of the rib 42. As Figures 7 - 9As shown, the inner circumferential rib 44 and the outer circumferential rib 45 are arranged such that when viewed along the radial direction DR, the vertex 44t of the inner circumferential rib does not coincide with the vertex 45t of the outer circumferential rib. Specifically, the vertex 44t of the inner circumferential rib is provided between two (adjacent) vertices 45t of the outer circumferential rib in the axial direction DX. Similarly, the inner axial rib 47 and the outer axial rib 48 are arranged such that when viewed along the radial direction DR, the vertex 47t of the inner axial rib does not coincide with the vertex 48t of the outer axial rib. Specifically, in the circumferential direction DC, the vertex 47t of the inner axial rib is provided between the vertices 48t of two (adjacent) outer axial ribs 48.

[0032] [Control of fluid] Next, with reference to Figure 2 and Figures 10 - 12 , the control of fluid achieved by the rotary valve 100 will be described. The rotary valve 100 in this embodiment controls two flow paths simultaneously. It should be noted that Figure 2 shows the rotary valve 100 with the rotor 2 set at the first position P1, Figure 10 is a diagram showing the rotary valve 100 set at the second position P2, Figure 11 is a diagram showing the rotary valve 100 set at the third position P3, Figure 12 is a diagram showing the rotary valve 100 set at the fourth position P4.

[0033] As Figure 2 shown, when the rotor 2 is set at the first position P1, the fluid supplied to the second port 122 flows through the first valve flow path L1 and toward the first port 121, and the fluid supplied to the fifth port 125 flows through the second valve flow path L2 and toward the fourth port 124.

[0034] Next, the rotor 2 rotates clockwise by a specified angle around the axis X from Figure 2 the first position P1 shown, and as Figure 10 shown, when the rotor 2 is set at the second position P2, the fluid supplied to the third port 123 flows through the first valve flow path L1 and is supplied to the first port 121. In addition, at the same time, the fluid supplied to the fifth port 125 flows through the second valve flow path L2 and toward the fourth port 124.

[0035] Then, the rotor 2 rotates clockwise by a specified angle around the axis X from Figure 10 the second position P2 shown, and as Figure 11 shown, when the rotor 2 is set at the third position P3, the fluid supplied to the second port 122 flows through the first valve flow path L1 and toward the fourth port 124. In addition, at the same time, the fluid supplied to the fifth port 125 flows through the second valve flow path L2 and toward the first port 121.

[0036] Next, the rotor 2 further rotates clockwise by a specified angle about the axis X from Figure 11 the third position P3 shown, as Figure 12 shown, when the rotor 2 is set at the fourth position P4, the fluid supplied to the third port 123 flows through the first valve flow path L1 and flows toward the fourth port 124. At the same time, the fluid supplied to the fifth port 125 flows through the second valve flow path L2 and flows toward the first port 121.

[0037] [Function and effect of the embodiment] As described above, according to the present embodiment, since the number of inner circumferential ribs 44 that are in sliding contact with the rotor 2 is less than the number of outer circumferential ribs 45, the sliding resistance can be reduced. In addition, since the number of inner circumferential ribs 44 that are in sliding contact with the rotor 2 is less than the number of outer circumferential ribs 45 that are in sliding contact with the housing 1, the frictional resistance between the housing 1 and the seal 4 increases, and it is possible to prevent adverse conditions such as the seal 4 shifting as the rotor 2 rotates.

[0038] In addition, since the two end portions of the circumferential rib 43 in the axial direction DX are composed of two rib groups 43g, the force acting on the seal 4 can be balanced, thereby suppressing the deformation (collapse) of the seal 4. In addition, since the rib group 43g includes two outer circumferential ribs 45 and one inner circumferential rib 44 provided between the two outer circumferential ribs 45, when a force (the force from the rotor 2) acts on the inner circumferential rib 44, bending can occur between the two outer circumferential ribs 45. As a result, the reaction force of the seal 4 on the rotor 2 can be reduced, thereby reducing the sliding resistance.

[0039] In addition, since the inner circumferential rib 44 and the outer circumferential rib 45 are arranged such that the inner circumferential rib vertex 44t of the inner circumferential rib 44 does not coincide with the outer circumferential rib vertex 45t of the outer circumferential rib 45 when viewed along the radial direction DR, when a force (the force from the rotor 2) acts on the inner circumferential rib 44, the seal 4 can bend outward, thereby reducing the reaction force of the seal 4 on the rotor 2.

[0040] In addition, since the inner circumferential rib inclined portion 44k is less inclined than the outer circumferential rib inclined portion 45k, the collapse of the inner circumferential rib 44 can be suppressed by the rotation of the rotor 2, thereby improving the durability of the seal 4. In addition, since the outer circumferential rib inclined portion 45k is steeper than the inner circumferential rib inclined portion 44k, the reaction force of the seal 4 on the rotor 2 can be reduced.

[0041] In addition, since the axial rib 46 extending along the axial direction DX is connected to the circumferential rib 43 extending along the circumferential direction DC, and the circumferential rib 43 and the axial rib 46 surround the sealing opening 41h through which the fluid flows in and out, the sealing performance of the seal 4 can be further improved.

[0042] In addition, since the connecting portions (the first connecting portion C1 and the second connecting portion C2) of the axial rib 46 and the circumferential rib 43 are rounded, in the entire sealing main body portion 41, it is possible to prevent the inner circumferential rib vertex 44t of the inner circumferential rib 44 from coinciding with the outer circumferential rib vertex 45t of the outer circumferential rib 45 in the radial direction DR. Thus, in the entire sealing main body portion 41, bending can occur between the outer circumferential rib vertices 45t, and thus the reaction force of the seal 4 on the rotor 2 can be reduced.

[0043] In addition, the inner circumferential rib 44 is provided with a sliding property improving layer LY made of a material having a smaller coefficient of friction than that of the outer circumferential rib 45 on its surface, so that the sliding resistance of the rotor 2 can be further reduced.

[0044] In addition, since the sealing main body portion 41 includes a convex portion 411 protruding in the radially outward direction DR2, and the convex portion 411 faces the housing wall portion 11 of the housing 1 in the circumferential direction DC, the rotation of the seal 4 relative to the housing 1 (co-rotating and shifting with the rotor 2) can be prevented.

[0045] In addition, by providing the outer circumferential rib 45 having a greater distance (radius) from the rotation center of the rotor 2 than the inner circumferential rib 44, the torque required to rotate the outer circumferential rib 45 becomes greater than the torque required to rotate the inner circumferential rib 44, so that the rotation of the seal 4 relative to the housing 1 can be suppressed.

[0046] [Other Embodiments] In addition to the above embodiments, the present invention can also be configured in the following manner (components having the same functions as those in the embodiments are labeled with the same numbers and symbols as those in the embodiments).

[0047] (1) In the present embodiment, although the case where the rib group 43g is composed of one inner circumferential rib 44 and two outer circumferential ribs 45 has been described, as long as the number of inner circumferential ribs 44 is less than the number of outer circumferential ribs 45, the number of the inner circumferential ribs 44 and the outer circumferential ribs 45 constituting the rib group 43g is not limited to the above case. For example, the rib group 43g can also be composed of two inner circumferential ribs 44 and three outer circumferential ribs 45.

[0048] (2) In the present embodiment, the case where the vertices of the inner ribs (inner circumferential rib vertices 44t and inner axial rib vertices 47t) do not coincide with the vertices of the outer ribs (outer circumferential rib vertices 45t and outer axial rib vertices 48t) when observed along the radial direction DR has been described. However, it is also possible that at least a part of the inner circumferential rib vertices 44t coincides with at least a part of the outer circumferential rib vertices 45t when observed along the radial direction DR. Similarly, it is also possible that at least a part of the inner axial rib vertices 47t coincides with at least a part of the outer axial rib vertices 48t when observed along the radial direction DR. That is, it is possible that at least a part of the vertices of the inner ribs coincides with at least a part of the vertices of the outer ribs when observed along the radial direction DR.

[0049] (3) In the present embodiment, the case where the inclined portions of the inner ribs (inner circumferential rib inclined portion 44k and inner axial rib inclined portion 47k) are less inclined than the inclined portions of the outer ribs (outer circumferential rib inclined portion 45k and outer axial rib inclined portion 48k) has been described. However, the inclination of the inner circumferential rib inclined portion 44k may not be less inclined than the outer circumferential rib inclined portion 45k. Similarly, the inclination of the inner axial rib inclined portion 47k may not be less inclined than the outer axial rib inclined portion 48k. That is, the inclination of the inner ribs may not be less inclined than the inclination of the outer ribs.

[0050] (4) In the present embodiment, the case where the first connecting portion C1 and the second connecting portion C2 are rounded has been described. However, at least one of the first connecting portion C1 and the second connecting portion C2 may not be rounded.

[0051] (5) In the present embodiment, the lubricity improvement layer LY may also be omitted in the inner circumferential ribs 44 and the inner axial ribs 47.

[0052] (6) In the present embodiment, the sealing main body portion 41 includes a convex portion 411 that prevents the seal 4 from rotating relative to the housing 1. However, the sealing main body portion 41 may also prevent the seal 4 from rotating relative to the housing 1 by a structure other than the convex portion 411 (for example, a convex portion protruding along the axial direction DX is engaged with the housing 1, etc.).

[0053] (7) In the present embodiment, the rotary valve 100 of the five-way valve has been described as an example. However, the rotary valve 100 may also be a three-way valve, a four-way valve, etc. That is, the number of ports 12 formed in the housing 1 (housing wall portion 11) is not limited to five, and can be appropriately changed according to the number of directions of the fluid controlled by the rotary valve 100.

[0054] (8) The fluid inlet and outlet are not limited to the cases described in the present embodiment and can be interchanged. That is, the fluid flow direction can also be reversed.

[0055] In the above-described embodiment, the following structure is reviewed.

[0056] (1) The seal 4 of the rotary valve 100 according to the present invention is characterized in the following aspects: It is the seal 4 of the rotary valve 100 disposed between the rotor 2 and the housing 1 that houses the rotor 2, and includes a seal main body portion 41 (main body portion) extending along the circumferential direction DC of the rotor 2 and the axial direction DX of the rotor 2, and a rib portion 42 protruding in the radial direction DR of the rotor 2 from the seal main body portion 41 (main body portion). The rib portion 42 has a circumferential rib portion 43 extending along the circumferential direction DC. The circumferential rib portion 43 includes an inner circumferential rib portion 44 protruding inward in the radial direction DR and an outer circumferential rib portion 45 protruding outward in the radial direction DR. The number of the inner circumferential rib portions 44 is less than the number of the outer circumferential rib portions 45. The inclination of the inner circumferential rib portion inclined portion 44k between the inner circumferential rib base end 44p and the inner circumferential rib apex 44t of the inner circumferential rib portion 44 is gentler than the inclination of the outer circumferential rib portion inclined portion 45k between the outer circumferential rib base end 45p and the outer circumferential rib apex 45t of the outer circumferential rib portion 45.

[0057] According to this structure, since the number of the inner circumferential rib portions 44 that are in sliding contact with the rotor 2 is less than the number of the outer circumferential rib portions 45, the sliding resistance of the rotor 2 can be reduced. In addition, since the inner circumferential rib portions 44 that are in sliding contact with the rotor 2 are fewer than the outer circumferential rib portions 45 that are in sliding contact with the housing 1, the frictional resistance between the housing 1 and the seal 4 becomes larger, thereby preventing adverse conditions such as the displacement of the seal 4 as the rotor 2 rotates. Further, according to this structure, since the inclination of the inner circumferential rib portion inclined portion 44k is gentler than that of the outer circumferential rib portion inclined portion 45k, the collapse of the inner circumferential rib portion 44 can be suppressed by the rotation of the rotor 2, and the durability of the seal 4 can be improved. In addition, since the inclination of the outer circumferential rib portion inclined portion 45k is steeper than that of the inner circumferential rib portion inclined portion 44k, the reaction force of the seal 4 on the rotor 2 can be reduced.

[0058] (2) In the seal 4 of the rotary valve 100 described in (1), the circumferential rib portion 43 is composed of two rib groups 43g provided at both ends in the axial direction DX. The rib group 43g may include two outer circumferential rib portions 45 and one inner circumferential rib portion 44 located between the two outer circumferential rib portions 45.

[0059] According to this structure, since the circumferential rib 43 is composed of two rib groups 43g at both ends in the axial direction DX, the force acting on the seal 4 can be balanced, thereby suppressing the deformation (collapse) of the seal 4. In addition, since the rib group 43g includes two outer circumferential ribs 45 and one inner circumferential rib 44 provided between the two outer circumferential ribs 45, when a force acts on the inner circumferential rib 44, bending can occur between the two outer circumferential ribs 45. As a result, the reaction force of the seal 4 on the rotor 2 can be reduced, thereby reducing the sliding resistance.

[0060] (3) In the seal 4 of the rotary valve 100 described in (1) or (2), the inner circumferential rib 44 and the outer circumferential rib 45 may be arranged such that when viewed along the radial direction DR, the inner circumferential rib vertex 44t of the inner circumferential rib 44 does not coincide with the outer circumferential rib vertex 45t of the outer circumferential rib 45.

[0061] According to this structure, since the inner circumferential rib vertex 44t does not coincide with the outer circumferential rib vertex 45t, when a force acts on the inner circumferential rib 44, the seal 4 can bend outward, thereby reducing the reaction force of the seal 4 on the rotor 2.

[0062] (4) In the seal 4 of the rotary valve 100 described in any one of (1) to (3), when viewed along the radial direction DR, the inner circumferential rib vertex 44t may be located between adjacent outer circumferential rib vertices 45t.

[0063] According to this structure, since the inner circumferential rib vertex 44t is located between adjacent outer circumferential rib vertices 45t, when a force acts on the inner circumferential rib 44, the seal 4 can bend outward, thereby reducing the reaction force of the seal 4 on the rotor 2.

[0064] (5) In the seal 4 of the rotary valve 100 described in any one of (1) to (4), the rib 42 further has an axial rib 46 extending along the axial direction DX and connected to the circumferential rib 43, and the circumferential rib 43 and the axial rib 46 can surround the seal opening 41h (opening) through which the fluid in the seal main body 41 (main body) passes.

[0065] According to this structure, the axial rib 46 extending along the axial direction DX is connected to the circumferential rib 43 extending along the circumferential direction DC, and the circumferential rib 43 and the axial rib 46 surround the seal opening 41h (opening) through which the fluid flows in and out, so the sealing performance can be further improved.

[0066] (6) In the seal 4 of the rotary valve 100 described in (5), the first connection portion C1 and the second connection portion C2 (connection portions) between the axial rib 46 and the circumferential rib 43 may be rounded.

[0067] According to this structure, since the first connecting portion C1 and the second connecting portion C2 (connecting portions) of the axial rib 46 and the circumferential rib 43 are rounded, in the entire sealing main body portion 41 (main body portion), it is possible to prevent the inner circumferential rib apex 44t of the inner circumferential rib portion 44 from coinciding with the outer circumferential rib apex 45t of the outer circumferential rib portion 45 in the radial direction DR. Thus, the reaction force of the seal 4 on the rotor 2 can be reduced.

[0068] (7) In the seal 4 of the rotary valve 100 according to any one of (1) to (6) above, the inner circumferential rib portion 44 may be provided on its surface with a sliding property improving layer LY made of a material having a friction coefficient smaller than that of the outer circumferential rib portion 45.

[0069] According to this structure, since the inner circumferential rib portion 44 is provided on its surface with a sliding property improving layer LY made of a material having a friction coefficient smaller than that of the outer circumferential rib portion 45, the sliding resistance of the rotor 2 can be further reduced.

[0070] (8) In the seal 4 of the rotary valve 100 according to any one of (1) to (7) above, the sealing main body portion 41 (main body portion) may include a convex portion 411 (rotation preventing portion) that protrudes outward in the radial direction DR so as to face the outer shell wall portion 11 (wall portion) of the outer shell 1 in the circumferential direction DC.

[0071] According to this structure, since the sealing main body portion 41 (main body portion) includes a convex portion 411 (rotation preventing portion) that protrudes outward in the radial direction DR, and the convex portion 411 (rotation preventing portion) faces the outer shell wall portion 11 (wall portion) of the outer shell 1 in the circumferential direction DC, the rotation (displacement) of the seal 4 relative to the outer shell 1 can be prevented. Industrial availability

[0072] The present invention can be applied to the seal of a rotary valve. Symbol description

[0073] 1: Housing, 2: Rotor, 11: Housing wall portion (wall portion), 4: Seal, 41: Seal main body portion (main body portion), 41h: Seal opening (opening), 42: Rib, 43: Circumferential rib, 43g: Rib group, 44: Inner circumferential rib, 44k: Inner circumferential rib inclined portion, 44p: Inner circumferential rib base end, 44t: Inner circumferential rib apex, 45: Outer circumferential rib, 45k: Outer circumferential rib inclined portion, 45p: Outer circumferential rib base end, 45t: Outer circumferential rib apex, 46: Axial rib, 100: Rotary valve, 411: Projection portion (rotation prevention portion), C1: First connection portion (connection portion), C2: Second connection portion (connection portion), DC: Circumferential direction, DR: Radial direction, DX: Axis direction, LY: Sliding property improvement layer, X: Axis.

Claims

1. A seal for a rotary valve, which is a seal for a rotary valve disposed between a rotor and a housing that houses the rotor, and includes: A main body portion that extends in the circumferential direction of the rotor and in the axial direction of the rotor; and Rib portions that project radially from the main body portion toward the rotor, The rib portions have circumferential rib portions that extend along the circumferential direction, The circumferential rib portions include an inner circumferential rib portion that projects inward in the radial direction and an outer circumferential rib portion that projects outward in the radial direction, The number of the inner circumferential rib portions is less than the number of the outer circumferential rib portions, Compared with the inclination of the outer circumferential rib portion inclined portion between the base end of the outer circumferential rib portion and the apex of the outer circumferential rib portion of the outer circumferential rib portion, the inclination of the inner circumferential rib portion inclined portion between the base end of the inner circumferential rib portion and the apex of the inner circumferential rib portion of the inner circumferential rib portion is gentler.

2. The seal for a rotary valve according to claim 1, wherein The circumferential rib portions are composed of two rib groups provided at both ends in the axial direction, Each rib group includes two of the outer circumferential rib portions and one of the inner circumferential rib portions between the two outer circumferential rib portions.

3. The seal for a rotary valve according to claim 1 or 2, wherein The inner circumferential rib portion and the outer circumferential rib portion are provided such that when viewed along the radial direction, the apex of the inner circumferential rib portion of the inner circumferential rib portion does not coincide with the apex of the outer circumferential rib portion of the outer circumferential rib portion.

4. The seal for a rotary valve according to claim 3, wherein When viewed along the radial direction, the apex of the inner circumferential rib portion is located between the adjacent apices of the outer circumferential rib portions.

5. The seal for a rotary valve according to claim 1 or 2, wherein The rib portions further have axial rib portions that extend in the axial direction and are connected to the circumferential rib portions, The circumferential rib portions and the axial rib portions surround an opening through which the fluid formed in the main body portion passes.

6. The seal for a rotary valve according to claim 5, wherein The connecting portion of the axial rib portion and the circumferential rib portion has a rounded shape.

7. The seal for a rotary valve according to claim 1 or 2, wherein The inner circumferential rib portion is provided with a sliding property improving layer on the surface, which is made of a material having a smaller coefficient of friction than that of the outer circumferential rib portion.

8. The seal for a rotary valve according to claim 1 or 2, wherein The main body portion includes a rotation preventing portion that projects outward in the radial direction so as to face the wall portion of the housing in the circumferential direction.

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