Rotary Valve

Abstract

To secure sealing force between a valve body part and an annular wall part and attach a packing to the annular wall part in a state that the packing is restricted from moving in a valve body rotation direction.SOLUTION: A housing 21 of a rotary valve 10 includes an annular wall part 23 formed around an axis L1 of a valve body 50 and having a second outflow port 35. The annular wall part 23 includes a packing attachment part 41 having an inner surface 42 extending along the axis L1 in a periphery of the second outflow port 35. A packing 60 includes a rubber packing body part 61 having a through hole 65 and having outer surfaces 62 extending along the axis L1 around the through hole 65. The packing 60 is attached to the packing attachment part 41 in a state that the through hole 65 faces the second outflow port 35 and each outer surface 62 faces the inner surface 42. The outer surface 62 is provided with a slide part 69 formed of a sheet made of a fluorine resin, and the slide part 69 slidably contacts with the inner surface 42.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a rotary valve. [Background technology]

[0002] As shown in Fig. 11, a known rotary valve 100 provided in the middle of a fluid flow path includes a housing 101 having an accommodating portion 106, and a valve element 108 supported by the housing 101 by a shaft (not shown). The housing 101 includes an annular wall portion 102 formed around the axis of the shaft. At least one of an inlet and an outlet for the fluid is formed in the annular wall portion 102 as a specific opening 103 facing the accommodating portion 106.

[0003] The valve body 108 includes a valve body 109 housed in the housing 106. A movable flow path 109a is formed in the valve body 109, which connects the inlet and the outlet. When the valve body 109 is rotated about its axis, the outlet that connects to the inlet via the movable flow path 109a is switched, and the flow path of the fluid is switched. In addition, the flow rate of the fluid flowing through the flow path is adjusted (see, for example, Patent Document 1).

[0004] The rotary valve 100 further includes a packing 110 disposed between the housing 101 and the valve body 109. The annular wall 102 includes a packing mounting portion 104 around the specific opening 103. The packing mounting portion 104 has a pair of inner surfaces 105 extending along the axis.

[0005] The framework of the packing 110 is constituted by a packing body 111. The packing body 111 has a through hole 112, and has a pair of outer surfaces 113 extending around the through hole 112 along the axis.

[0006] The packing body 111 is attached to the packing attachment portion 104 with the through hole 112 facing the specific opening 103 and with each outer surface 113 in contact with the opposing inner surface 105 .

[0007] In the rotary valve 100, a reaction force (hereinafter referred to as a "compression reaction force F1") that pushes back the valve body 109 is generated in the packing 110 by compressing the packing 110 between the annular wall portion 102 and the valve body portion 109. In the rotary valve 100, the gap between the valve body portion 109 and the annular wall portion 102 is sealed by the compression reaction force F1. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2009-180240 A Summary of the Invention [Problem to be solved by the invention]

[0009] In the conventional rotary valve 100, when the packing 110 is attached to the packing attachment portion 104, each outer surface 113 of the packing body 111 comes into contact with the opposing inner surface 105 of the packing attachment portion 104. This restricts the movement of the packing 110 in the rotational direction of the valve body 108. However, frictional force is generated between the outer surface 113 and the inner surface 105, and the compression reaction force F1 is weakened by the frictional force. As a result, the sealing force of the packing 110 that seals between the valve body 109 and the annular wall portion 102 is reduced.

[0010] To cope with this, it is possible to ensure the compression reaction force F1, and therefore the sealing force, by compressing the packing 110 more. However, this would require a large torque to rotate the valve body . [Means for solving the problem]

[0011] A rotary valve that solves the above problem includes a housing having an accommodation portion, and a fluid inlet and outlet formed facing the accommodation portion, a valve element supported by the housing by a shaft, and a packing arranged between the housing and the valve element, the valve element being accommodated in the accommodation portion and including a valve body portion having a movable flow passage formed therein for connecting the inlet and the outlet, the valve body portion rotating about the axis of the shaft, the housing including an annular wall portion formed around the axis and at least one of the inlet and the outlet formed as a specific opening, the annular wall portion being arranged along the axis The packing has a packing mounting portion having an inner surface extending around the specific opening, the packing has a through hole and a packing main body portion having an outer surface extending along the axis around the through hole, the packing is mounted on the packing mounting portion with the through hole facing the specific opening and the outer surface facing the inner surface, and a sliding portion is provided between the outer surface and the inner surface, the sliding portion being fixed to one of the packing main body portion and the annular wall portion and in slidable contact with the other, and the sliding portion is formed of a material having a smaller friction coefficient than the member of the packing main body portion and the annular wall portion to which the sliding portion is fixed.

[0012] According to the above configuration, when the packing is attached to the packing attachment portion, the through hole faces the specific opening. Also, the outer surface of the packing main body faces the inner surface of the packing attachment portion. A sliding portion is interposed between the outer surface and the inner surface. Therefore, the outer surface is in indirect contact with the inner surface via the sliding portion. This contact restricts the packing from moving in the rotational direction of the valve body.

[0013] In a rotary valve, the packing is compressed between the annular wall and the valve body. A reaction force (compression reaction force) is generated in the packing, which pushes back against the valve body. This compression reaction force creates a seal between the valve body and the annular wall.

[0014] Here, the sliding portion is made of a material having a smaller friction coefficient than the packing body and the annular wall to which the sliding portion is fixed. Therefore, the frictional force generated between the outer surface and the inner surface is smaller than when the outer surface and the inner surface are in direct contact with each other without the sliding portion. Therefore, the degree to which the compression reaction force is weakened by the frictional force is reduced. As a result, the deterioration of the sealing force of the packing is suppressed.

[0015] In order to ensure the sealing force, it is not necessary to compress the packing significantly, and it is possible to suppress an increase in the torque required to rotate the valve body. In the above rotary valve, it is preferable that the packing body is made of rubber, and the sliding portion is made of fluororesin and fixed to the outer surface of the packing body.

[0016] According to the above-mentioned configuration, the coefficient of friction of the fluororesin forming the sliding part is smaller than the coefficient of friction of the rubber forming the packing body to which the sliding part is fixed, and therefore the frictional force generated between the outer surface of the packing body and the inner surface of the packing mounting part is smaller than when these surfaces are in direct contact with each other.

[0017] In the above rotary valve, it is preferable that the sliding portion is formed of a fluororesin sheet, and the sheet is attached to the outer surface of the packing body. According to the above-mentioned configuration, by attaching and fixing the fluororesin sheet to the outer surface of the packing body, it is possible to reduce the frictional force generated between the inner surface of the packing mounting portion and the outer surface of the packing body.

[0018] In the above rotary valve, it is preferable that a low-friction sheet made of a fluororesin is affixed to the surface of the packing body facing the valve body, the low-friction sheet extends to the outer surface of the packing body and is affixed to the outer surface, and the sliding part consisting of the fluororesin sheet is constituted by the extended portion of the low-friction sheet.

[0019] According to the above-mentioned configuration, the low-friction sheet made of fluororesin, which is originally used to reduce the friction between the packing body and the valve body, is extended to the outer surface of the packing body. This extended portion is attached to the outer surface to form a sliding portion fixed to the outer surface. Effect of the Invention

[0020] According to the above rotary valve, the packing can be attached to the annular wall in a state in which movement in the rotational direction of the valve disc is restricted while ensuring a sealing force between the valve body and the annular wall. [Brief description of the drawings]

[0021] [Figure 1] FIG. 2 is a perspective view of a portion of a rotary valve as viewed from one side along the axis of a shaft in a valve body. [Diagram 2] FIG. 4 is a perspective view of a part of the rotary valve as viewed from another side along the axis. [Diagram 3] FIG. 2 is an exploded perspective view of some components of a rotary valve as viewed from one side along the axis. [Figure 4] FIG. 4 is an exploded perspective view of some components of the rotary valve as viewed from another side along the axis. [Diagram 5] Cross-sectional view of a rotary valve. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] Cross-sectional view of the packing. [Figure 9] FIG. 9 is an enlarged cross-sectional view of part A in FIG. 8 . [Figure 10] 13 is a bottom view of the body, valve element, and packing of the rotary valve as viewed from the other side along the axis. FIG. [Figure 11] FIG. 1 is a partial cross-sectional view of a conventional rotary valve. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, one embodiment of a rotary valve will be described with reference to FIGS. 5, the rotary valve 10 is provided in the middle of a flow path of a fluid FL, such as water, supplied from a fluid supply source, such as a pump (not shown). More specifically, this flow path includes a common flow path 11 connected to the fluid supply source, and a first branch flow path 12 and a second branch flow path 13 branched from the common flow path 11. The rotary valve 10 is disposed at a portion where the first branch flow path 12 and the second branch flow path 13 branch from the common flow path 11, and serves to adjust the flow rate of the fluid FL flowing through the first branch flow path 12 and the second branch flow path 13. By adjusting this flow rate, it is possible to cause the fluid FL to flow through both the first branch flow path 12 and the second branch flow path 13, or only one of them.

[0023] 3 and 4, the rotary valve 10 includes a housing 21, a valve body 50, and a pair of packings 60. Next, each of the members will be described. <Housing 21> As shown in Figures 1 and 2, the housing 21 includes a body 22. The body 22 includes an annular wall portion 23 formed around the axis L1 of the shafts 58, 59 of the valve body 50. One end of the annular wall portion 23 in the direction along the axis L1 is blocked by a blocking portion 24. The other end of the annular wall portion 23 forms an open end 25 that is open. The open end 25 is blocked by a cover (not shown). The area surrounded by the body 22 and the cover constitutes a storage portion 26.

[0024] 5, in the annular wall portion 23, an inlet 27 for the fluid FL into the storage portion 26, and a first outlet 31 and a second outlet 35 for the fluid FL in the storage portion 26 are formed at three positions spaced apart from one another in the rotational direction of the valve body 50, each facing the storage portion 26. In this embodiment, the first outlet 31 and the second outlet 35 form specific openings to be sealed by the packing 60.

[0025] A connecting pipe section 28 protruding away from the storage section 26 is provided on the peripheral edge of the inlet 27 on the outer wall surface of the annular wall section 23. The connecting pipe section 28 and the fluid supply source are connected by a pipe 29 having the above-mentioned common flow path 11 for the fluid FL.

[0026] A connecting pipe section 32 is provided on the peripheral edge of the first outlet 31 on the outer wall surface of the annular wall section 23, protruding away from the storage section 26. A pipe 33 having the first branch flow path 12 for the fluid FL is connected to the connecting pipe section 32. The fluid FL flowing out from the first outlet 31 is sent through the pipe 33 to a destination where the fluid FL is used.

[0027] A connecting pipe section 36 is provided on the peripheral edge of the second outlet 35 on the outer wall surface of the annular wall section 23, protruding away from the storage section 26. A pipe 37 having the second branch flow path 13 for the fluid FL is connected to the connecting pipe section 36. The fluid FL flowing out from the second outlet 35 is sent through the pipe 37 to a destination where the fluid FL is used.

[0028] A concave packing mounting portion 41 is formed around each of the first outlet 31 and the second outlet 35 on the inner wall of the annular wall 23. Each packing mounting portion 41 has a pair of inner surfaces 42 extending along the axis L1. The inner surfaces 42 of the packing mounting portion 41 around the first outlet 31 are located on both sides of the first outlet 31 in the rotation direction of the valve body 50, and face each other in the rotation direction with the first outlet 31 between them. Similarly, the inner surfaces 42 of the packing mounting portion 41 around the second outlet 35 are located on both sides of the second outlet 35 in the rotation direction of the valve body 50, and face each other in the rotation direction with the second outlet 35 between them. Each packing mounting portion 41 has a concavely curved inner wall surface 43 between the inner surfaces 42.

[0029] 1 and 3, a bearing hole 44 extending in a direction along the axis L1 is formed in the blocking portion 24. Similarly, a bearing hole (not shown) extending in a direction along the axis L1 is formed in the center portion of the cover.

[0030] <Valve body 50> 3 and 4, the valve body 50 includes a valve body 51 constituting a framework thereof, and shafts 58 and 59. The shafts 58 and 59 protrude from the valve body 51 on both sides in a direction along the axis L1. The valve body 50 is supported by the shaft 58 so as to be rotatable relative to the bearing hole 44 of the closure part 24. The valve body 50 is also supported by the shaft 59 so as to be rotatable relative to the bearing hole of the cover.

[0031] The valve main body 51 has a cylindrical shape extending generally along the axis L1, and is disposed within the housing portion . 3 and 5, the valve body 51 includes a pair of end wall portions 52, 53 each having a disk shape, and a connecting portion 55. The end wall portions 52, 53 are disposed spaced apart from each other in the direction along the axis L1. The connecting portion 55 is disposed between a part of the outer periphery of the end wall portion 52 and a part of the outer periphery of the end wall portion 53, and connects the end wall portions 52, 53. The outer periphery of the end wall portions 52, 53 and the outer periphery of the connecting portion 55 form an outer periphery 56 of the valve body 51.

[0032] In the valve main body 51, the portion between the end wall portions 52, 53, excluding the connecting portion 55, constitutes a movable flow path 57 that connects the inlet 27 to the first outlet 31 and the second outlet 35. The movable flow path 57 opens at an outer circumferential surface 56 of the valve main body 51.

[0033] The valve body 50 having the above configuration is rotated by a motor (not shown), manual operation, or the like. As shown in FIG. 5, this rotation allows the valve body 51 to close a part of the first outlet 31 and a part of the second outlet 35, thereby allowing the common flow path 11 to communicate with the first branch flow path 12 and the second branch flow path 13. Although not shown, the valve body 51 can close the first outlet 31 and open the entire second outlet 35 to allow the common flow path 11 to communicate with the second branch flow path 13. Conversely, the valve body 51 can close the second outlet 35 and open the entire first outlet 31 to allow the common flow path 11 to communicate with the first branch flow path 12. The rotation of the valve body 50 allows the opening degree of each of the first outlet 31 and the second outlet 35 to be adjusted.

[0034] <Packing 60> Each packing 60 is disposed between the annular wall portion 23 and the valve body portion 51. Each packing 60 has the same configuration as the others.

[0035] 6 to 8, each packing 60 includes a packing body 61, a first seal portion 66, and a second seal portion 67. The packing body 61, the first seal portion 66, and the second seal portion 67 are integrally formed from an elastic material, which is rubber in this embodiment.

[0036] Each packing body 61 is a part that constitutes the framework of the packing 60, and has a rectangular outer shape. Each packing body 61 is in the form of a rectangular plate whose thickness direction is the radial direction of the axis L1.

[0037] Each packing body 61 has a through hole 65 at a position facing the first outlet 31 or the second outlet 35. Each through hole 65 is formed of a circular hole having a diameter approximately equal to that of the first outlet 31 or the second outlet 35, respectively, and functions as a passage for the fluid FL. Each through hole 65 is formed to a size that allows the through hole 65 to be blocked by the connecting portion 55.

[0038] Each packing body 61 has a pair of outer surfaces 62 extending along the axis L1 on both sides of a through hole 65 in the rotational direction of the valve body 50. The surface of each packing body 61 facing the annular wall 23 (first outlet 31 or second outlet 35) is formed by a curved surface 63 that is curved convexly along the inner wall surface 43 of the packing mounting portion 41. The surface of each packing body 61 facing the valve body 51 is formed by a curved surface 64 that is curved concavely along the outer circumferential surface 56 of the valve body 51.

[0039] Each first seal portion 66 is the curved surface 63 of each packing body portion 61, and protrudes from the periphery of the through hole 65 toward the annular wall portion 23 (the first outlet 31, the second outlet 35). As described above, since the curved surface 63 is curved convexly along the inner wall surface 43 of the packing mounting portion 41, each first seal portion 66 is also curved convexly along the inner wall surface 43 (see FIGS. 3 and 4).

[0040] Further, each second seal portion 67 is the curved surface 64 of each packing body 61, and protrudes from the periphery of the through hole 65 toward the valve body 51 to form an annular shape. Here, as described above, since the curved surface 64 is curved concavely along the outer peripheral surface 56 of the valve body 51, each second seal portion 67 is also curved concavely along the outer peripheral surface 56.

[0041] A low-friction sheet 68 made of fluororesin is attached to the curved surface 64 of each packing body 61, the second seal portion 67, and the inner wall surface of the through hole 65. The low-friction sheet 68 extends to both outer side surfaces 62 of the packing body 61 and is attached to the outer side surfaces 62. The extended portions of the low-friction sheet 68 constitute sliding portions 69 made of a sheet made of fluororesin.

[0042] Next, the operation of the present embodiment configured as described above will be described, along with the effects that accompany the operation. 5 and 10, in the rotary valve 10, each packing 60 is attached to the packing attachment portion 41 and disposed between the annular wall portion 23 and the valve body portion 51. The through hole 65 of one packing 60 faces the first outlet 31. The through hole 65 of the other packing 60 faces the second outlet 35.

[0043] 8 and 9, a pair of outer surfaces 62 of each packing 60 face the corresponding inner surfaces 42 of the packing mounting portion 41. In this state, a sliding portion 69 is interposed between the outer surface 62 and the inner surface 42. Therefore, each outer surface 62 is in indirect contact with each inner surface 42 via the sliding portion 69. Due to this contact, the movement of each packing 60 in the rotation direction of the valve body 50 is restricted.

[0044] The first seal portion 66 of each packing 60 is in contact with the inner wall surface 43 of the packing attachment portion 41 around the first outlet 31 or the second outlet 35 . Furthermore, the portions of the low-friction sheet 68 that are attached to the curved surface 64 of the packing body 61 and the second seal portion 67 are in slidable contact with the outer circumferential surface 56 of the valve body 51 .

[0045] In the state of contacting the inner wall surface 43 and the outer circumferential surface 56 as described above, the packing 60 is compressed between the annular wall portion 23 and the valve main body portion 51. As a result of this compression, a reaction force (compression reaction force F1) that pushes back the valve main body portion 51 is generated in the packing 60. The compression reaction force F1 seals the gap between the valve main body portion 51 and the annular wall portion 23.

[0046] Here, the packing body 61 and the second seal portion 67 are made of rubber, whereas the low-friction sheet 68 is made of fluororesin. The friction coefficient of fluororesin is smaller than that of rubber. The packing body 61 and the second seal portion 67 are indirectly in contact with the valve body 51 via the low-friction sheet 68. Therefore, the friction force generated between the packing 60 and the valve body 51 can be reduced compared to a case where the packing body 61 and the second seal portion 67 are in direct contact with the outer circumferential surface 56 of the valve body 51 without the low-friction sheet 68 being interposed. As a result, the torque required to rotate the valve body 50 can be reduced.

[0047] In addition, each sliding portion 69 is also formed of fluororesin. A pair of sliding portions 69 for each packing 60 are in slidable contact with the corresponding inner surface 42 of the packing mounting portion 41. A pair of outer surfaces 62 for each packing 60 are in indirect slidable contact with the inner surface 42 via the sliding portions 69.

[0048] Therefore, the frictional force generated between the outer surface 62 and the inner surface 42 of the packing body 61 is smaller than that in the case where the outer surface 62 and the inner surface 42 of the packing mounting portion 41 are in direct contact with each other without the interposition of the sliding portion 69. Therefore, the degree to which the compression reaction force F1 is weakened by the frictional force is reduced. Accordingly, the decrease in the sealing force of the packing 60 is suppressed.

[0049] In order to ensure the sealing force, it is not necessary to compress the packing 60 much, and it is possible to suppress an increase in the torque required to rotate the valve body 50. Because the valve body 50 can be rotated with a small torque, the load applied to the mechanism for rotation can be reduced, and the product life of the rotary valve 10 can be extended.

[0050] In addition, when the first outlet 31 or the second outlet 35 is blocked by the valve body 51, the packing 60 is in contact with the outer circumferential surface 56 of the valve body 51 at the second seal portion 67 while being pressed against the outer circumferential surface 56 of the valve body 51. Therefore, even if the fluid FL enters between the valve body 51 and the packing body 61, the fluid FL is unlikely to leak into the area surrounded by the first seal portion 66 and the second seal portion 67 on the outer circumferential surface 56 of the valve body 51. This can suppress the phenomenon of the fluid FL leaking from the blocked first outlet 31 to the first branch flow path 12, or the phenomenon of the fluid FL leaking from the blocked second outlet 35 to the second branch flow path 13.

[0051] In addition to the above, the present embodiment provides the following effects. In this embodiment, the low-friction sheet 68 made of fluororesin, which is originally used to reduce the frictional force between the packing 60 and the valve body 51, is extended to the outer surface 62 of the packing body 61. By attaching this extended portion to the outer surface 62, a sliding portion 69 fixed to the outer surface 62 can be formed.

[0052] In other words, by using a single low-friction sheet 68 made of fluororesin, it is possible to reduce both the frictional force between the gasket 60 and the valve main body 51 and the frictional force between the gasket main body 61 and the gasket mounting portion 41.

[0053] In other words, the low-friction sheet 68 made of fluororesin can be fixed to the curved surface 64 of the packing body 61, the second seal portion 67, the inner wall surface of the through hole 65, and both outer surfaces 62 at the same time.

[0054] The above embodiment can also be implemented as modified examples that are changed 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.

[0055] <Matters related to Housing 21> The number of outlets in the annular wall portion 23 may be changed to one or three or more. In accordance with this change in the number of outlets, the number of packings 60 used is also changed.

[0056] The inlet 27 may be formed in a location in the housing 21 other than the annular wall portion 23, for example, in the closing portion 24. The housing 21 may be provided with a plurality of inlets that open toward the storage section 26 .

[0057] The inner wall surface 43 of the packing mounting portion 41 may be configured as a flat surface. <Matters regarding the valve body 50> The opening shape of the movable flow passage 57 on the outer circumferential surface 56 of the valve body 51 may be changed to a shape different from that in the above embodiment.

[0058] The valve body 51 may be formed in a spherical shape instead of a cylindrical shape. <Matters regarding packing 60> The packing body 61, the first seal portion 66, and the second seal portion 67 may be made of an elastic material other than rubber. In this case, the sliding portion 69 is made of a material having a smaller friction coefficient than the elastic material.

[0059] The through hole 65 in the packing 60 may be formed in a shape other than a circle. At least one of the first seal portion 66 and the second seal portion 67 may be formed in a ring shape different from the outer shape of the through-hole 65, for example, an elliptical ring shape, a polygonal ring shape, or the like.

[0060] <Matters related to the sliding portion 69> Each sliding portion 69 may be fixed to the inner surface 42 of the packing attachment portion 41 instead of or in addition to the outer surface 62 of the packing body portion 61 .

[0061] Each sliding portion 69 may be configured with a film instead of a sheet. The film can be formed by coating with a material with a low coefficient of friction, such as fluororesin. In this case, the same effects and advantages as those of the above embodiment can be obtained.

[0062] Each sliding portion 69 may be formed from a material other than fluororesin, provided that the material has a smaller friction coefficient than the member to which the sliding portion 69 is fixed, among the packing main body portion 61 and the annular wall portion 23.

[0063] Each sliding portion 69 may be fixed to the packing body portion 61 or the annular wall portion 23 by a means other than adhesion. In addition to the low friction sheets 68 on the curved surface 64 of each packing body 61, the second seal portion 67, and the inner wall surface of the through hole 65, each sliding portion 69 may be provided.

[0064] <Other> The low-friction sheets 68 made of fluororesin on the curved surfaces 64 of the packing main bodies 61, the second seal portions 67, and the inner wall surfaces of the through holes 65 may be omitted.

[0065] Instead of or in addition to the first outlet 31 and the second outlet 35, the inlet 27 may be the specific opening. In this case, the annular wall portion 23 includes a packing mounting portion 41 having an inner surface 42 extending along the axis L1, around the inlet 27. The packing 60 is mounted on the packing mounting portion 41 with the through hole 65 of the packing main body portion 61 facing the inlet 27 and the outer surface 62 facing the inner surface 42. A sliding portion 69 is provided between the outer surface 62 and the inner surface 42, which is fixed to one of the packing main body portion 61 and the annular wall portion 23 and slidably contacts the other.

[0066] The rotary valve 10 described above can also be used as a rotary valve provided in a flow path through which a liquid other than water flows as a fluid, or as a rotary valve provided in a flow path through which gas flows as a fluid instead of a liquid. [Explanation of symbols]

[0067] 10...Rotary valve 21. Housing 23...Annular wall portion 26…Storage section 27…Inlet 31...1st outlet (outlet, specific opening) 35...Second outlet (outlet, specific opening) 41…Packing attachment part 42…Inner surface 50…Valve body 51...Valve body 57... Movable flow path 58,59…Axis 60…Packing 61...Packing body 62…Outer surface 65...Through hole 68...Low friction sheet 69…Sliding part FL…Fluid L1…Axis line

Claims

1. A rotary valve comprising: a housing having a storage portion, and an inlet and an outlet for a fluid formed facing the storage portion; a valve element supported by the housing by a shaft; and a packing arranged between the housing and the valve element, the valve element being accommodated in the storage portion and comprising a valve body portion having a movable flow passage formed therein for communicating the inlet and the outlet, the valve body portion rotating about the axis of the shaft, The housing includes an annular wall portion formed around the axis, and at least one of the inlet and the outlet is formed as a specific opening; The annular wall portion includes a packing mounting portion, The packing attachment portion has a pair of inner surfaces extending along the axis at locations on both sides of the specific opening in the rotational direction of the valve body, and facing each other in the rotational direction with the specific opening between them, The packing includes a packing body having a through hole, The packing body has a pair of outer surfaces extending along the axis at locations on both sides of the valve body in the rotation direction, the pair of outer surfaces being opposed to the valve body, The packing is attached to the packing attachment portion in a state in which the through hole faces the specific opening and the pair of outer side surfaces faces the pair of inner side surfaces, A rotary valve in which a sliding portion is provided between the opposing outer surface and inner surface, the sliding portion being fixed to one of the packing body portion and the annular wall portion and in slidable contact with the other, for each combination of the opposing outer surface and inner surface, the sliding portion being formed from a material having a smaller coefficient of friction than the material to which the sliding portion is fixed, of the packing body portion and the annular wall portion.

2. The packing body is made of rubber, 2. The rotary valve according to claim 1, wherein the sliding portion is made of a fluororesin and is fixed to the outer surface of the packing body.

3. The sliding portion is made of a fluororesin sheet, 3. The rotary valve according to claim 2, wherein the sheet is attached to the outer surface of the packing body.

4. A low-friction sheet made of fluororesin is attached to the surface of the packing body facing the valve body, 4. The rotary valve according to claim 3, wherein the low-friction sheet extends to the outer surface of the packing body and is affixed to the outer surface, and the sliding portion made of the fluororesin sheet is configured by the extended portion of the low-friction sheet.

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