Rotary valve

Abstract

To provide a rotary valve capable of smoothly displacing an on-off valve between a closing position and an opening position.SOLUTION: A rotary valve 30 comprises an on-off valve 180 which rotates between a closing position to close the air outlet 162a of a rotary 160 and an opening position to open the air outlet 162a of the rotary 160 by sliding with the sliding surfaces 72a, 72b, and 72c of a valve case 70 caused by the rotation of the rotary 160.SELECTED DRAWING: Figure 22

Description

[Technical Field]

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

[0002] Patent Document 1 describes a massage seat that massages the body of a seated user. The massage seat includes a plurality of air bladders built into the seat cushion and seat back, a pump that supplies air to the plurality of air bladders, and a rotary valve that switches the air supply mode to the plurality of air bladders. The rotary valve includes a case, a center piston, and a rotary.

[0003] The case houses the components of the rotary valve. The case has a supply joint connected to the pump and multiple connection joints respectively connected to multiple air bladders. The supply joint is located at the bottom end of the case, and the multiple connection joints are located at the top end of the case. The center piston, together with the case, defines an air chamber. The air chamber is connected to the pump via the supply joint. The center piston moves up and down within the case as the pressure in the air chamber increases or decreases. The rotary is located above the case. The rotary has a supply flow path connecting the air chamber to one of the connection joints, and an exhaust flow path connecting the intake flow path to the outside air. The rotary also has an on-off valve that moves between a closed position that closes the opening of the exhaust flow path and an open position that opens the opening of the exhaust flow path. The rotary rotates in conjunction with the up and down movement of the center piston, thereby sequentially switching the connection joints connected to the supply flow path. The on-off valve moves between a closed position and an open position in accordance with the rotation of the rotary.

[0004] When the rotary rotates in response to a decrease in pressure in the air chamber, connecting a supply flow path to a certain connection joint, the on-off valve is placed in the closed position. In this case, air is supplied to the air bag corresponding to the certain connection joint, and the pressure in the air chamber increases. When the rotary then rotates in response to the increase in pressure in the air chamber, the on-off valve is displaced to the open position. Air is then discharged from the air bag corresponding to the certain connection joint, and the pressure in the air chamber decreases. When the rotary then rotates in response to the decrease in pressure in the air chamber, the supply flow path is connected to the next connection joint, and the on-off valve is displaced to the closed position. In this way, the rotary valve sequentially inflates and deflates multiple air bags. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-81064 Summary of the Invention [Problem to be solved by the invention]

[0006] In the rotary valve described above, the on-off valve is displaced from an open position to a closed position by sliding against the case as the rotary rotates. For this reason, there is still room for improvement in the rotary valve described above in terms of smoothly displacing the on-off valve from the closed position to the open position. [Means for solving the problem]

[0007] The rotary valve that solves the above problem is a rotary valve that sequentially inflates and deflates a plurality of air bladders by switching the air supply mode to the plurality of air bladders, and includes a case that defines an air chamber to which air is supplied from a pump, the case having a plurality of connecting flow paths whose downstream ends are connected to the plurality of air bladders respectively, a center piston that rises as the pressure in the air chamber increases and falls as the pressure in the air chamber decreases, an air intake flow path that is located above the center piston and connected to the air chamber, and an exhaust flow path that connects the air intake flow path to the outside air, and the rise and fall of the center piston and a rotary that rotates about an axis extending in the vertical direction to sequentially switch the connection flow paths connected to the air intake flow path in response to the rotation of the rotary. The rotary further has an on-off valve that is displaced between a closed position that closes an exhaust port, which is an opening in the exhaust flow path that connects to the outside air, and an open position that opens the exhaust port while the air intake flow path is connected to one of the connection flow paths. The case further has a sliding surface whose distance to the rotation axis of the rotary changes in the rotation direction of the rotary, and the on-off valve is displaced while rotating between the closed position and the open position by sliding against the sliding surface of the case as the rotary rotates. [Effects of the Invention]

[0008] The rotary valve allows smooth transition of the on-off valve between the closed and open positions. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a seat equipped with a rotary valve. [Figure 2] FIG. 2 is a perspective view of the rotary valve of FIG. [Figure 3] FIG. 3 is an exploded perspective view of the rotary valve of FIG. [Figure 4] FIG. 4 is an exploded perspective view of the rotary valve of FIG. [Figure 5] FIG. 5 is a cross-sectional view of the cylinder of the rotary valve of FIG. [Figure 6]FIG. 6 is a cross-sectional view of the lower guide of the rotary valve of FIG. [Figure 7] 7 is a cross-sectional view of the upper guide of the rotary valve of FIG. 1. FIG. [Figure 8] FIG. 8 is a half cross-sectional view of the valve case of the rotary valve of FIG. [Figure 9] FIG. 9 is a bottom view of the valve case of the rotary valve of FIG. [Figure 10] 10 is a top view of the nozzle holder and the upper nozzle of the rotary valve of FIG. 1. FIG. [Figure 11] FIG. 11 is a cross-sectional view of the lower piston of the rotary valve of FIG. [Figure 12] FIG. 12 is a cross-sectional view of the center piston of the rotary valve of FIG. [Figure 13] 13 is a cross-sectional view of the pressing portion of the rotary valve of FIG. [Figure 14] 14 is an exploded perspective view of the rotary of the rotary valve of FIG. 1. FIG. [Figure 15] FIG. 15 is an exploded perspective view of the rotary of FIG. [Figure 16] FIG. 16 is a top view of the rotary of FIG. [Figure 17] 17 is a cross-sectional view of the rotary of FIG. 16 taken along line 17-17. [Figure 18] FIG. 18 is a top view of the rotary valve of FIG. [Figure 19] FIG. 19 is a cross-sectional view of the rotary valve of FIG. 18 taken along line AA. [Figure 20] 20 is a cross-sectional view of the rotary valve of FIG. 18 taken along the line BB. [Figure 21] FIG. 21 is a schematic diagram showing the position of the boss base of the rotary valve of FIG. [Figure 22] 22 is a cross-sectional view of the rotary valve of FIG. 20 taken along line 22-22. [Figure 23] 23 is a cross-sectional view of the rotary valve of FIG. 18 taken along the line BB when the lower piston is raised. [Figure 24] 24 is a cross-sectional view of the rotary valve of FIG. 18 taken along the line BB when the lower piston and the center piston are raised. [Figure 25] FIG. 25 is a schematic diagram showing the movement of the boss base of the rotary valve of FIG. [Figure 26] 26 is a cross-sectional view of the rotary valve of FIG. 24 taken along line 26-26. [Figure 27] 27 is a cross-sectional view of the rotary valve of FIG. 18 taken along the line BB when the lower piston and the center piston are lowered. [Figure 28] FIG. 28 is a schematic diagram showing the movement of the boss base of the rotary valve of FIG. [Figure 29] 29 is a cross-sectional view of the rotary valve of FIG. 27 taken along line 29-29. [Figure 30] FIG. 30 is a cross-sectional view of the rotary valve of FIG. 18 taken along line CC when the lower piston and the center piston are lowered. [Figure 31] FIG. 31 is a cross-sectional view of the rotary valve of FIG. 18 taken along line AA when the driving of the pump is stopped. [Figure 32] FIG. 32 is a cross-sectional view of the rotary valve of FIG. 18 taken along line AA when the driving of the pump is stopped. DETAILED DESCRIPTION OF THE INVENTION

[0010] A seat equipped with a rotary valve will be described below with reference to the drawings. To clearly illustrate the cross-sectional view, the hatching used in the cross-sectional view is of a metallic type, regardless of the material of the member.

[0011] <Configuration of this embodiment> 1, the seat 10 includes a seat cushion 11, a seat back 12, and an air pressure system 20. The seat 10 is, for example, a vehicle seat such as a driver's seat, a passenger seat, or a rear seat of a vehicle. In another embodiment, the seat 10 may be a massage seat used in facilities, homes, etc.

[0012] <Air Pressure System 20> The air pressure system 20 includes eight air bags 21 (21a to 21h), eight connection tubes 22, a supply tube 23, a pump 24, and a rotary valve 30. The air pressure system 20 is preferably built into the seat 10.

[0013] The eight air bladders 21 are built into the seat cushion 11 and the seat back 12. More specifically, three air bladders 21a to 21c are built into the seat cushion 11. Five air bladders 21d to 21h are built into the seat back 12. The three air bladders 21a to 21c are configured to massage the buttocks and legs of a user seated in the seat 10. Meanwhile, the five air bladders 21d to 21h are configured to massage the back of a user seated in the seat 10. The air bladders 21 expand when air is supplied thereto and contract when air is discharged therefrom. For example, the air bladders 21 may be formed by welding the outer edges of two resin films together. In other embodiments, the number of air bladders 21 can be changed as appropriate.

[0014] The eight connecting tubes 22 connect the eight air bladders 21 to the rotary valve 30. The supply tube 23 connects the pump 24 to the rotary valve 30. The connecting tubes 22 and the supply tube 23 preferably have appropriate elasticity so that they can be easily routed inside the seat 10. In other embodiments, the connecting tubes 22 and the supply tube 23 may be plastic pipes and steel pipes.

[0015] The pump 24 may be any pump that can deliver air. The pump 24 is driven by power supplied from a battery (not shown). In the following description, upstream and downstream are referred to according to the flow of air delivered by the pump 24. In this respect, the pump 24 is located at the most upstream position in the pneumatic system 20.

[0016] <Rotary Valve 30> The rotary valve 30 is a device that switches the mode of air supply to the eight air bladders 21, thereby inflating and deflating the eight air bladders 21 in sequence.

[0017] As shown in FIG. 2 , the rotary valve 30 has a cylindrical shape. In the following description, the axial direction of the rotary valve 30 is referred to as the vertical direction Z, the direction perpendicular to the vertical direction Z is referred to as the first direction X, and the direction perpendicular to both the vertical direction Z and the first direction X is referred to as the second direction Y. The radial direction of the rotary valve 30 is simply referred to as the radial direction, and the circumferential direction C of the rotary valve 30 is simply referred to as the circumferential direction C. The circumferential direction C further includes a first circumferential direction C1 and a second circumferential direction C2, which is the opposite direction to the first circumferential direction C1. The rotary valve 30 also includes many components whose axial, radial, and circumferential directions C are the same as those of the rotary valve 30. Therefore, when describing these components, the axial, radial, and circumferential directions C of these components will be simply referred to as the axial, radial, and circumferential directions C.

[0018] The up-down direction Z of the rotary valve 30 is unrelated to the up-down direction Z of the seat 10 on which the rotary valve 30 is mounted. For example, when the rotary valve 30 is mounted on the seat 10, the up-down direction Z of the rotary valve 30 may be the front-to-rear direction of the seat 10 or the width direction of the seat 10.

[0019] 2 to 4, the rotary valve 30 includes a cylinder 40, a lower guide 50, an upper guide 60, a valve case 70, a nozzle holder 80, eight upper nozzles 90, and two clamps 100. The rotary valve 30 also includes a lower piston 110, a center piston 120, a boss base 130, a stopper ring 140, a pressing portion 150, a rotary 160, a lower spring SP1, a center spring SP2, and a pressing spring SP3. In this embodiment, the cylinder 40, the lower guide 50, the upper guide 60, and the valve case 70 form a "case."

[0020] <Cylinder 40> 3 to 5, the cylinder 40 includes a bottom wall 41, a peripheral wall 42, a lower nozzle 43, four lower clamp holders 44, four lower clamp guides 45, and two positioning protrusions 46. The cylinder 40 is, for example, a resin molded product.

[0021] The bottom wall 41 is disk-shaped. The axial direction of the bottom wall 41 is the vertical direction Z. The bottom wall 41 has a communicating hole 41a. The peripheral wall 42 is cylindrical. The axial direction of the peripheral wall 42 is the vertical direction Z. The peripheral wall 42 extends upward from the outer edge of the bottom wall 41. The lower nozzle 43 is located in the center of the bottom wall 41 and extends downward from the underside of the bottom wall 41. The lower nozzle 43 is connected to the interior of the cylinder 40 via the communicating hole 41a. The lower nozzle 43 is the portion to which the downstream end of the supply tube 23 is connected.

[0022] The four lower clamp holders 44 are provided on the underside of the bottom wall 41. The four lower clamp holders 44 are lined up two by two in the first direction X and the second direction Y. The lower clamp holders 44 are configured to hold the clamps 100. The four lower clamp guides 45 protrude from the bottom wall 41 along the first direction X. When the cylinder 40 is viewed from the bottom, the four lower clamp guides 45 are lined up two by two in the first direction X and the second direction Y. The lower clamp guides 45 are configured to hold the clamps 100 together with the lower clamp holders 44. The two positioning protrusions 46 protrude upward from the upper end of the peripheral wall 42. The two positioning protrusions 46 are lined up at equal intervals in the circumferential direction C.

[0023] <Lower Guide 50> 3, 4, and 6, the lower guide 50 includes an intermediate wall 51, an inner peripheral wall 52, a lower outer peripheral wall 53, and an upper outer peripheral wall 54. The lower guide 50 is, for example, a resin molded product.

[0024] The intermediate wall 51 is shaped like a disk with a hole in the center. The thickness direction of the intermediate wall 51 is the up-down direction Z. The intermediate wall 51 has two positioning recesses 51a. The two positioning recesses 51a are recessed from the outer surface in the radial direction toward the axis of the intermediate wall 51. The two positioning recesses 51a are arranged at equal intervals in the circumferential direction C.

[0025] The inner circumferential wall 52 is cylindrical. The axial direction of the inner circumferential wall 52 is the vertical direction Z. The inner circumferential wall 52 extends upward and downward from the inner edge of the intermediate wall 51. The inner circumferential wall 52 has a plurality of lower sliding surfaces 52a and a plurality of lower regulating surfaces 52b. The number of the lower sliding surfaces 52a and the number of the lower regulating surfaces 52b are both "8", the same as the number of the air bags 21. The eight lower sliding surfaces 52a and the eight lower regulating surfaces 52b are arranged alternately in the circumferential direction C. The lower sliding surfaces 52a are inclined downward as they extend in the first circumferential direction C1. In other words, the lower regulating surfaces 52b intersect both the vertical direction Z and the circumferential direction C. The lower regulating surfaces 52b extend in the vertical direction Z. In other words, the lower regulating surfaces 52b are surfaces that are perpendicular to the circumferential direction C. In this embodiment, the lower restriction surface 52b connects the front ends in the first circumferential direction C1 of the lower sliding surfaces 52a adjacent to each other in the circumferential direction C to the rear ends in the first circumferential direction C1 of the lower sliding surfaces 52a.

[0026] The lower outer peripheral wall 53 and the upper outer peripheral wall 54 are cylindrical. The axial direction of the lower outer peripheral wall 53 and the axial direction of the upper outer peripheral wall 54 are the vertical direction Z. The lower outer peripheral wall 53 extends downward from the intermediate wall 51, and the upper outer peripheral wall 54 extends upward from the intermediate wall 51. The inner diameters of the lower outer peripheral wall 53 and the upper outer peripheral wall 54 are larger than the outer diameter of the inner peripheral wall 52. In this respect, a space exists between the lower outer peripheral wall 53 and the inner peripheral wall 52 in the radial direction, and a space also exists between the upper outer peripheral wall 54 and the inner peripheral wall 52. The upper outer peripheral wall 54 has two positioning recesses 54a. The two positioning recesses 54a are recessed downward from the upper surface of the upper outer peripheral wall 54. The two positioning recesses 54a are arranged at equal intervals in the circumferential direction C. In the lower guide 50, the positions where the two positioning recesses 51a are formed and the positions where the two positioning recesses 54a are formed are aligned in the vertical direction Z.

[0027] <Upper guide 60> 3, 4, and 7, the upper guide 60 includes an intermediate wall 61, an inner peripheral wall 62, an outer peripheral wall 63, and two positioning protrusions 64. The upper guide 60 is, for example, a resin molded product.

[0028] The intermediate wall 61 is disk-shaped with a hole in the center. The thickness direction of the intermediate wall 61 is the vertical direction Z. The inner peripheral wall 62 is cylindrical. The axial direction of the inner peripheral wall 62 is the vertical direction Z. The inner peripheral wall 62 extends upward and downward from the inner edge of the intermediate wall 61. The inner diameter of the inner peripheral wall 62 is equal to the inner diameter of the inner peripheral wall 52 of the lower guide 50.

[0029] The inner circumferential wall 62 has a plurality of upper sliding surfaces 62a and a plurality of upper restricting surfaces 62b. The number of upper sliding surfaces 62a and upper restricting surfaces 62b is "8", the same as the number of air bags 21. The eight upper sliding surfaces 62a and the eight upper restricting surfaces 62b are arranged alternately in the circumferential direction C. The upper sliding surfaces 62a are inclined upward as they proceed in the first circumferential direction C1. In other words, the upper restricting surfaces 62b intersect both the up-down direction Z and the circumferential direction C. In the circumferential direction C, the length of the upper sliding surfaces 62a is equal to the length of the lower sliding surfaces 52a. The upper restricting surfaces 62b extend in the up-down direction Z. In other words, the upper restricting surfaces 62b are surfaces that are perpendicular to the circumferential direction C. The upper restriction surface 62b connects the front end of the upper sliding surface 62a in the first circumferential direction C1 to the rear end of the upper sliding surface 62a in the first circumferential direction C1.

[0030] The outer peripheral wall 63 has a cylindrical shape. The axial direction of the outer peripheral wall 63 is the vertical direction Z. The outer peripheral wall 63 extends upward and downward from the outer edge of the intermediate wall 61. The inner diameter of the outer peripheral wall 63 is larger than the outer diameter of the inner peripheral wall 62. The outer peripheral wall 63 has four locking holes 63a and four positioning recesses 63b, 63c. The four locking holes 63a penetrate the outer peripheral wall 63 in the radial direction. The four locking holes 63a are aligned in the circumferential direction C of the outer peripheral wall 63. The four positioning recesses 63b, 63c are recessed downward from the upper end of the intermediate wall 61. The four positioning recesses 63b, 63c are aligned at equal intervals in the circumferential direction C. Two positioning recesses 63b and two positioning recesses 63c are aligned alternately in the circumferential direction C. Two positioning protrusions 64 protrude downward from the lower end of the outer peripheral wall 63. The two positioning protrusions 64 are arranged at equal intervals in the circumferential direction C. The positions where the two positioning protrusions 64 are formed and the positions where the two positioning recesses 63b are formed are aligned in the up-down direction Z.

[0031] <Valve case 70> 3, 4, 8, and 9, the valve case 70 includes an upper wall 71, a peripheral wall 72, eight cylindrical walls 73, four upper clamp holders 74, four locking projections 75, and two positioning projections 76. The valve case 70 is, for example, a resin molded product.

[0032] The upper wall 71 has a circular plate shape. The axial direction of the upper wall 71 is the vertical direction Z. The upper wall 71 has an axial hole 71a and eight connecting flow passages 77 (77a to 77h). The axial hole 71a and the eight connecting flow passages 77 penetrate the upper wall 71 in the plate thickness direction. The axial hole 71a and the eight connecting flow passages 77 form a circular shape in a plan view in the vertical direction Z. The axial hole 71a is located in the center of the upper wall 71. When the upper wall 71 is viewed from the vertical direction Z, the eight connecting flow passages 77 are aligned at equal intervals in the circumferential direction C. The distances from the axis of the valve case 70 to the positions where the eight connecting flow passages 77 are formed in the upper wall 71 are equal. The lower ends of the eight connecting flow passages 77, i.e., the upstream ends of the eight connecting flow passages 77, open to the lower surface of the upper wall 71. On the other hand, the upper ends of the eight connecting flow paths 77, i.e., the downstream ends of the eight connecting flow paths 77, open to the upper surface of the upper wall 71. In the following description, the lower surface of the upper wall 71 of the valve case 70 will be referred to as the "opening surface 71b."

[0033] The peripheral wall 72 has a cylindrical shape. The axial direction of the peripheral wall 72 is the up-down direction Z. The peripheral wall 72 extends downward from the outer edge of the upper wall 71. As shown in FIG. 9 , the peripheral wall 72 has eight first sliding surfaces 72a, eight second sliding surfaces 72b, eight third sliding surfaces 72c, and eight connecting surfaces 72d. The first sliding surfaces 72a, the second sliding surfaces 72b, the third sliding surfaces 72c, and the connecting surfaces 72d are inner surfaces of the peripheral wall 72. The eight first sliding surfaces 72a, the eight second sliding surfaces 72b, the eight third sliding surfaces 72c, and the eight connecting surfaces 72d are arranged in order in the circumferential direction C.

[0034] In the bottom view shown in FIG. 9 , the first sliding surface 72a and the third sliding surface 72c are surfaces that follow an arc centered on the axis of the circumferential wall 72. The radius of the arc that forms the first sliding surface 72a is larger than the radius of the arc that forms the third sliding surface 72c. In other words, the distance from the axis of the valve case 70 to the first sliding surface 72a is longer than the distance from the axis of the valve case 70 to the third sliding surface 72c. The second sliding surface 72b intersects both the radial direction and the circumferential direction C. The second sliding surface 72b extends radially inward as it advances in the first circumferential direction C1. The second sliding surface 72b connects the first sliding surface 72a and the third sliding surface 72c, which are positioned radially offset from each other. The connecting surface 72d is a surface that extends radially. The connecting surface 72d connects the first sliding surface 72a and the third sliding surface 72c, which are positioned radially offset from each other. The first sliding surface 72a, the second sliding surface 72b, and the third sliding surface 72c correspond to the "sliding surfaces of the case."

[0035] As shown in FIGS. 3, 4, and 8, the cylindrical wall 73 has a cylindrical shape. The axial direction of the cylindrical wall 73 is the vertical direction Z. The cylindrical wall 73 extends upward from the upper wall 71. In a plan view in the vertical direction Z, the eight cylindrical walls 73 are arranged at equal intervals in the circumferential direction C. In this embodiment, two cylindrical walls 73 adjacent to each other in the circumferential direction C are integrally formed, but in other embodiments, two cylindrical walls 73 adjacent to each other in the circumferential direction C may be formed separately. The upper ends of the eight connecting flow paths 77, i.e., the downstream ends of the eight connecting flow paths 77, open into the internal space of the eight cylindrical walls 73. In other words, one connecting flow path 77 is connected to the internal space of one cylindrical wall 73.

[0036] The four upper clamp holders 74 protrude from the peripheral wall 72 in the first direction X. The four upper clamp holders 74 are lined up two by two in the first direction X and the second direction Y. The upper clamp holders 74 are configured to hold the clamp 100. Four locking protrusions 75 protrude from each of the four upper clamp holders 74. The locking protrusions 75 protrude from the upper clamp holder 74 in the second direction Y. The length of the locking protrusions 75 in the protruding direction increases downward. Two positioning protrusions 76 protrude downward from the lower end of the cylindrical wall 73. The two positioning protrusions 76 are lined up at equal intervals in the circumferential direction C.

[0037] <Nozzle holder 80> 3, 4, and 10, the nozzle holder 80 has a holding wall 81, a peripheral wall 82, four connecting walls 83, and four locking walls 84. The nozzle holder 80 is, for example, a resin molded product.

[0038] The retaining wall 81 is disk-shaped. The thickness direction of the retaining wall 81 is the up-down direction Z. The retaining wall 81 has eight support holes 81a. The eight support holes 81a penetrate the retaining wall 81 in the thickness direction. The eight support holes 81a are arranged at equal intervals in the circumferential direction C. The retaining wall 81 supports eight upper nozzles 90 via the eight support holes 81a. When the retaining wall 81 supports the upper nozzles 90, the upper nozzles 90 cannot move in the thickness direction relative to the retaining wall 81. The peripheral wall 82 is cylindrical. The axial direction of the peripheral wall 82 is the up-down direction Z. The peripheral wall 82 extends downward from the outer edge of the retaining wall 81.

[0039] The four connecting walls 83 are plate-shaped. The thickness direction of the four connecting walls 83 is the vertical direction Z. When viewed from the vertical direction Z, the connecting walls 83 are triangular. The four connecting walls 83 extend from the lower end of the peripheral wall 82 in the second direction Y. The four locking walls 84 are plate-shaped. The thickness direction of the four locking walls 84 is the second direction Y. The four locking walls 84 extend downward from the four connecting walls 83, respectively. The locking walls 84 have locking holes 84a. The locking holes 84a penetrate the locking walls 84 in the thickness direction. The locking holes 84a are shaped to correspond to the locking protrusions 75 of the valve case 70. In this embodiment, the locking holes 84a are rectangular when viewed from the second direction Y.

[0040] <Clamp 100> As shown in Fig. 2, the clamp 100 has a long rod shape. The clamp 100 is formed, for example, by bending an elastically deformable metal wire. The elastic modulus of the clamp 100 is preferably such that the worker assembling the rotary valve 30 can elastically deform the clamp 100. Here, the worker may be a human or a robot.

[0041] <Lower Piston 110> 3, 4, and 11, the lower piston 110 includes a main body 111, a first seal SL1, and a second seal SL2. The main body 111 is molded from, for example, a resin material, and the first seal SL1 and the second seal SL2 are molded from, for example, an elastomer such as rubber.

[0042] The main body 111 has a bottom wall 112 , an upper wall 113 , an inner peripheral wall 114 , an outer peripheral wall 115 , a first support wall 116 , and a second support wall 117 . The bottom wall 112 is disk-shaped. The axial direction of the bottom wall 112 is the vertical direction Z. The bottom wall 112 has a communicating flow path 112a. The communicating flow path 112a penetrates the center of the bottom wall 112 in the plate thickness direction. The inner diameter of the communicating flow path 112a is larger than the inner diameter of the communicating hole 41a of the cylinder 40. In other words, the flow path cross-sectional area of ​​the communicating flow path 112a is larger than the flow path cross-sectional area of ​​the communicating hole 41a of the cylinder 40. The formation position of the communicating flow paths 112a and the number of communicating flow paths 112a can be changed as appropriate. The upper wall 113 is disk-shaped with a hole in the center. The axial direction of the upper wall 113 is the vertical direction Z. The upper wall 113 is located higher than the bottom wall 112.

[0043] The inner peripheral wall 114 and the outer peripheral wall 115 are cylindrical. The axial direction of the inner peripheral wall 114 and the axial direction of the outer peripheral wall 115 are the vertical direction Z. The inner peripheral wall 114 connects the outer edge of the bottom wall 112 and the inner edge of the top wall 113 in the vertical direction Z. The inner diameter of the outer peripheral wall 115 is larger than the outer diameter of the inner peripheral wall 114. The outer peripheral wall 115 extends downward from the top wall 113. A gap exists between the outer peripheral wall 115 and the inner peripheral wall 114 in the radial direction. The first support wall 116 is flange-shaped. The thickness direction of the first support wall 116 is the vertical direction Z. The first support wall 116 extends radially outward from the lower end of the outer peripheral wall 115. The second support wall 117 is annular. The axial direction of the second support wall 117 is the vertical direction Z. The second support wall 117 protrudes upward from the upper wall 113 .

[0044] The first seal SL1 is annular. The first seal SL1 is supported by the upper wall 113, the outer peripheral wall 115, and the first support wall 116. More specifically, the first seal SL1 is disposed in an area defined by the lower surface of the upper wall 113, the outer surface of the outer peripheral wall 115, and the upper surface of the first support wall 116. The first seal SL1 is the radially outermost member of the lower piston 110. The second seal SL2 is annular. The second seal SL2 is supported by the upper wall 113 and the second support wall 117 of the main body 111. At this time, the second seal SL2 is in contact with the upper surface of the upper wall 113 and the outer surface of the second support wall 117. The second seal SL2 is the uppermost member of the lower piston 110.

[0045] <Center piston 120> 3, 4, and 12, the center piston 120 includes a shaft portion 121, a sliding flange 122, a support flange 123, a plurality of reinforcing ribs 124, and two protrusions 125. The center piston 120 also has an internal flow path 126. The center piston 120 is, for example, a resin molded product.

[0046] The shaft portion 121 is cylindrical. An internal space penetrating the shaft portion 121 in the vertical direction Z is an internal flow path 126. The flow path cross-sectional area of ​​the internal flow path 126 is larger than the flow path cross-sectional area of ​​the communicating flow path 112a of the lower piston 110. The axial direction of the shaft portion 121 is the vertical direction Z. The sliding flange 122 and the support flange 123 are disk-shaped. The thickness directions of the sliding flange 122 and the support flange 123 are the vertical direction Z. The sliding flange 122 extends radially outward from the lower end of the shaft portion 121. The outer diameter of the sliding flange 122 is slightly smaller than the inner diameter of the cylinder 40. The support flange 123 extends radially outward from a middle portion of the shaft portion 121 in the vertical direction Z. The outer diameter of the support flange 123 is smaller than the outer diameter of the sliding flange 122.

[0047] The multiple reinforcing ribs 124 are plate-shaped. The thickness direction of the multiple reinforcing ribs 124 is perpendicular to the vertical direction Z. The multiple reinforcing ribs 124 connect the sliding flange 122 and the support flange 123 in the vertical direction Z. The two protrusions 125 protrude radially outward from the tip of the shaft portion 121. The two protrusions 125 are arranged at equal intervals in the radial direction.

[0048] <Boss base 130 and stopper ring 140> As shown in Figures 3 and 4, the boss base 130 has a cylindrical shape. The axial direction of the boss base 130 is the vertical direction Z. The boss base 130 has six bosses 131. The boss base 130 also has two engagement recesses 132. The boss base 130 is, for example, a resin molded product.

[0049] The six bosses 131 protrude radially outward from the outer peripheral surface of the boss base 130. The six bosses 131 are aligned in the circumferential direction C. The six bosses 131 are formed at the same position in the up-down direction Z. When one boss 131 is viewed from the front in the protruding direction, the boss 131 has a triangular shape.

[0050] The boss 131 has a lower cam surface 131a, an upper cam surface 131b, and an abutment surface 131c as surfaces perpendicular to the protruding direction. The lower cam surface 131a is inclined downward as it progresses in the first circumferential direction C1. The upper cam surface 131b is inclined upward as it progresses in the first circumferential direction C1. The lower end of the upper cam surface 131b is connected to the upper end of the lower cam surface 131a. The abutment surface 131c extends in the vertical direction Z. The abutment surface 131c connects the lower end of the lower cam surface 131a and the upper end of the upper cam surface 131b. The inclination of the lower cam surface 131a with respect to the vertical direction Z is equal to the inclination of the lower sliding surface 52a of the lower guide 50 in the vertical direction Z. Similarly, the inclination of the upper cam surface 131b with respect to the vertical direction Z is equal to the inclination of the upper sliding surface 62a of the upper guide 60 with respect to the vertical direction Z.

[0051] The two engagement recesses 132 are recessed from the outer peripheral surface of the boss base 130 toward the axis of the boss base 130. The two engagement recesses 132 are provided across the boss base 130 in the up-down direction Z. Therefore, the outer peripheral surface of the boss base 130 is separated in the circumferential direction C by the two engagement recesses 132. The two engagement recesses 132 are aligned at equal intervals in the circumferential direction C.

[0052] 3 and 4, the stopper ring 140 is annular. The axial direction and thickness direction of the stopper ring 140 are both in the vertical direction Z. The thickness of the stopper ring 140 is constant. The stopper ring 140 is, for example, a resin molded product.

[0053] <Pressing section 150> 3, 4, and 13, the pressing portion 150 includes an annular plate 151, four locking portions 152, and two engagement pieces 153. The pressing portion 150 is made of, for example, a metal material or a resin material.

[0054] The annular plate 151 is plate-shaped. The thickness direction of the annular plate 151 is the vertical direction Z. The annular plate 151 is annular in plan view in the vertical direction Z. The annular plate 151 has a sliding protrusion 151a that protrudes upward. The sliding protrusion 151a is annular in plan view in the vertical direction Z. In other words, the sliding protrusion 151a has a uniform cross-sectional shape in the circumferential direction C. The cross-sectional shape of the sliding protrusion 151a perpendicular to the circumferential direction C is semicircular.

[0055] The four locking portions 152 extend from the outer edge of the annular plate 151. The four locking portions 152 are arranged at intervals in the circumferential direction C. The locking portions 152 extend radially outward as they extend downward from the outer edge of the annular plate 151. In other words, the extending direction of the locking portions 152 is inclined with respect to both the up-down direction Z and the radial direction. The tips of the locking portions 152 are claw-shaped. The two engagement pieces 153 are plate-shaped. The thickness direction of the two engagement pieces 153 is the up-down direction Z. The two engagement pieces 153 protrude radially from the annular plate 151. The two engagement pieces 153 are arranged at equal intervals in the circumferential direction C.

[0056] <Rotary 160> 3, 4, and 14 to 17, the rotary 160 includes a rotary body 170, an on-off valve 180, a torsion spring 200, a third seal SL3, and a fourth seal SL4. The rotary 160 also has an air intake passage 161 and an exhaust passage 162. The third seal SL3 and the fourth seal SL4 are molded from an elastomer such as rubber.

[0057] The rotary body 170 has a bottom wall 171, a lower shaft portion 172, an upper shaft portion 173, two support flanges 174, two transmission shafts 175, a flow path forming portion 176, a link support shaft 177, a first engagement shaft 178, and a second engagement shaft 179. The rotary body 170 is, for example, a resin molded product.

[0058] The bottom wall 171 is disk-shaped. The axial direction of the bottom wall 171 is the vertical direction Z. The lower shaft portion 172 and the upper shaft portion 173 are cylindrical. The axial direction of the lower shaft portion 172 and the axial direction of the upper shaft portion 173 are the vertical direction Z. The lower shaft portion 172 extends downward from the center of the lower surface of the bottom wall 171. On the other hand, the upper shaft portion 173 extends upward from the center of the upper surface of the bottom wall 171. The axis of the upper shaft portion 173 coincides with the axis of the lower shaft portion 172.

[0059] The two support flanges 174 extend radially outward from the lower shaft portion 172. The two support flanges 174 are positioned at an interval in the up-down direction Z. A third seal SL3 is disposed between the two support flanges 174. The two support flanges 174 limit movement of the third seal SL3 in the up-down direction Z relative to the rotary body 170. The two transmission shafts 175 extend downward from the lower surface of the bottom wall 171. The two transmission shafts 175 are arranged at equal intervals in the circumferential direction C.

[0060] The flow path forming portion 176 extends upward from the upper surface of the bottom wall 171. The flow path forming portion 176 has a recessed groove 176a that is recessed downward from the upper surface of the flow path forming portion 176. When the rotary body 170 is viewed from above, the recessed groove 176a has a frame shape. A fourth seal SL4 is fitted into the recessed groove 176a.

[0061] The link support shaft 177, the first engagement shaft 178, and the second engagement shaft 179 are cylindrical. The axial direction of the link support shaft 177, the first engagement shaft 178, and the second engagement shaft 179 is the vertical direction Z. The link support shaft 177, the first engagement shaft 178, and the second engagement shaft 179 extend upward from the bottom wall 171 at a position offset from the flow path configuration portion 176. When the rotary body 170 is viewed from above, the link support shaft 177 is located between the first engagement shaft 178 and the second engagement shaft 179.

[0062] The air intake flow path 161 is provided across the bottom wall 171 of the rotary body 170, the lower shaft portion 172, and the flow path forming portion 176. The air intake flow path 161 opens to the lower surface of the lower shaft portion 172 and the upper surface of the flow path forming portion 176. Hereinafter, the upstream end of the air intake flow path 161 that opens to the lower surface of the lower shaft portion 172 will be referred to as an air intake port 161a, and the downstream end of the air intake flow path 161 that opens to the upper surface of the flow path forming portion 176 will be referred to as a connection port 161b. The exhaust flow path 162 is provided in the flow path forming portion 176. The exhaust flow path 162 is a flow path that connects the air intake flow path 161 to the outside air. Hereinafter, the opening of the exhaust flow path 162 that connects to the outside air will be referred to as an exhaust port 162a. The exhaust port 162a opens radially outward in the flow path forming portion 176.

[0063] The on-off valve 180 includes a valve body 181 and a link arm 190 . Valve element 181 is preferably made of an elastomer such as rubber or resin having appropriate elasticity. Valve element 181 may have any shape as long as it can close exhaust port 162a of rotary body 170.

[0064] The link arm 190 has an arm body 191 and a sliding portion 196. In the link arm 190, the arm body 191 and the sliding portion 196 are molded integrally. The link arm 190 is, for example, a resin molded product. The link arm 190 is rod-shaped. In the plate thickness direction, which is a direction perpendicular to the longitudinal direction of the link arm 190, the external shape of the link arm 190 is approximately constant.

[0065] The arm main body 191 constitutes the majority of the link arm 190. In this respect, the longitudinal direction of the arm main body 191 is the same as the longitudinal direction of the link arm 190. The arm main body 191 includes an arm lower surface 191a and an arm upper surface 191b that intersect with the plate thickness direction, and a first side surface 191c and a second side surface 191d that are surfaces along the plate thickness direction. The arm main body 191 also includes a shaft hole 192, an accommodating groove 193, a retracting groove 194, and a holding groove 195.

[0066] The shaft hole 192 is provided at the base end of the arm main body 191 in the longitudinal direction. The shaft hole 192 is recessed from the arm lower surface 191a toward the arm upper surface 191b. The shaft hole 192 is a circular hole. The accommodating groove 193 is provided from the base end to the tip end of the arm main body 191. The accommodating groove 193 is recessed from the arm lower surface 191a toward the arm upper surface 191b. The accommodating groove 193 is connected to the shaft hole 192. The retraction groove 194 is recessed from the first side surface 191c toward the second side surface 191d of the arm main body 191. The retraction groove 194 is connected to the accommodating groove 193. The holding groove 195 is provided on the second side surface 191d of the arm main body 191, closer to the tip end than to the base end of the arm main body 191. The holding groove 195 penetrates the arm main body 191 in the plate thickness direction. The valve body 181 is fitted into the holding groove 195. In this manner, the link arm 190 holds the valve body 181.

[0067] The sliding portion 196 is provided on the first side surface 191c of the arm main body 191 at the tip of the arm main body 191. The sliding portion 196 protrudes from the arm main body 191 in the radial direction of the shaft hole 192. The sliding portion 196 has a pressing surface 196a that forms the tip of the sliding portion 196, and a pressure-receiving surface 196b that forms the upper surface of the sliding portion 196. The pressing surface 196a is a convex curved surface with respect to the protruding direction of the sliding portion 196. The pressure-receiving surface 196b is connected to the arm upper surface 191b. The pressure-receiving surface 196b is inclined with respect to the protruding direction of the sliding portion 196. For this reason, the length of the sliding portion 196 in the plate thickness direction gradually becomes shorter as it progresses in the protruding direction.

[0068] The on-off valve 180 is rotatably supported by the rotary body 170. More specifically, a link support shaft 177 of the rotary body 170 is inserted into an axial hole 192 of a link arm 190. Thus, the on-off valve 180 is rotatable around the axis of the link support shaft 177. When the on-off valve 180 is supported by the rotary body 170, the valve element 181 faces the exhaust port 162a of the rotary body 170 in the rotation direction of the link arm 190. Therefore, when the on-off valve 180 rotates so that the valve element 181 approaches the exhaust port 162a, the valve element 181 is displaced to a closed position that closes the exhaust port 162a. On the other hand, when the on-off valve 180 rotates so that the valve element 181 moves away from the exhaust port 162a, the valve element 181 is displaced to an open position that opens the exhaust port 162a. In the following description, the rotation direction of the on-off valve 180 when it moves from the open position to the closed position is referred to as the "closing direction," and the rotation direction of the on-off valve 180 when it moves from the closed position to the open position is referred to as the "opening direction." The closing direction is the opposite direction to the opening direction. Furthermore, when the on-off valve 180 is supported by the rotary body 170, the retraction groove 194 of the link arm 190 opens toward the second engagement shaft 179 of the rotary body 170 in the rotation direction of the link arm 190.

[0069] The torsion spring 200 has a coil portion 201, a first arm 202 extending from a first end of the coil portion 201, and a second arm 203 extending from a second end of the coil portion 201. The length of the first arm 202 is equal to the length of the second arm 203. The torsion spring 200 is supported by the rotary body 170. More specifically, the link support shaft 177 of the rotary body 170 is inserted into the coil portion 201 of the torsion spring 200. The first arm 202 of the torsion spring 200 engages with the first engagement shaft 178 of the rotary body 170, and the second arm 203 of the torsion spring 200 engages with the second engagement shaft 179 of the rotary body 170. In this respect, the first engagement shaft 178 corresponds to a "first arm engagement portion" that can engage with the first arm 202, and the second engagement shaft 179 corresponds to a "second arm engagement portion" that can engage with the second arm 203. In addition, the coil portion 201 of the torsion spring 200, the base end portion of the first arm 202, and the second arm 203 are housed in the housing groove 193 of the link arm 190.

[0070] When the on-off valve 180 rotates in the closing direction, the on-off valve 180 rotates in the closing direction together with the second arm 203 of the torsion spring 200. In other words, when the on-off valve 180 rotates in the closing direction, the torsion spring 200 is elastically deformed. In this way, the on-off valve 180 is biased in the opening direction.

[0071] A method for manufacturing the rotary 160 will now be briefly described. The manufacturing method of the rotary 160 includes a seal assembling step, a spring assembling step, and an on-off valve assembling step.

[0072] The seal assembling process is a process of assembling the third seal SL3 and the fourth seal SL4 to the rotary body 170. The seal assembling process may be a process before or after the spring assembling process and the on-off valve assembling process.

[0073] The spring assembling process is a process of assembling the torsion spring 200 to the rotary body 170. In the spring assembling process, the link support shaft 177 of the rotary body 170 is inserted into the coil portion 201 of the torsion spring 200. In addition, the first arm 202 and the second arm 203 of the torsion spring 200 are engaged with the first engagement shaft 178 and the second engagement shaft 179 of the rotary body 170, respectively. In the spring assembling process, the torsion spring 200 is elastically compressed and deformed. Therefore, the first arm 202 and the second arm 203 of the torsion spring 200 are in contact with the first engagement shaft 178 and the second engagement shaft 179 of the rotary body 170, respectively.

[0074] The on-off valve assembling process is a process that follows the spring assembling process. The on-off valve assembling process is a process of assembling the on-off valve 180 to the rotary body 170 to which the torsion spring 200 has been assembled. In the on-off valve assembling process, the link support shaft 177 of the rotary body 170 is inserted into the shaft hole 192 of the on-off valve 180. In addition, the second engagement shaft 179 of the rotary body 170 is accommodated in the retraction groove 194 of the on-off valve 180. In addition, the on-off valve 180 is placed on the bottom wall 171 of the rotary body 170 between the flow path forming portion 176 and the second engagement shaft 179 of the rotary body 170. At this time, the coil portion 201 of the rotary 160 is accommodated in the shaft hole 192 of the on-off valve 180, and the base end portion of the first arm 202 and the second arm 203 of the coil spring are accommodated in the accommodation groove 193 of the on-off valve 180. The posture of the torsion spring 200 does not change before and after the on-off valve 180 is assembled. Specifically, as shown in Figure 16, the posture of the torsion spring 200 does not change after the on-off valve 180 is assembled to the rotary body 170 compared to before the on-off valve 180 is assembled to the rotary body 170. Therefore, there is no need to elastically deform the torsion spring 200 when assembling the on-off valve 180 to the rotary body 170. Therefore, the spring assembly process and the on-off valve assembly process can be performed separately.

[0075] <Engagement Relationship of Components of Rotary Valve 30> The engagement relationships of the components of the rotary valve 30 will be described with reference to Figures 3, 4, 18 and 19. Figures 18 and 19 show the rotary valve 30 in an assembled state.

[0076] The engagement relationship of the outer components of the rotary valve 30 will now be described. 3, 4, and 19, the lower guide 50 is stacked on top of the cylinder 40. The two positioning protrusions 46 of the cylinder 40 are inserted into the two positioning recesses 51a of the lower guide 50, respectively. As a result, the lower guide 50 is unable to rotate in the circumferential direction C with respect to the cylinder 40.

[0077] The upper guide 60 is stacked on top of the lower guide 50. The two positioning protrusions 64 of the upper guide 60 are inserted into the two positioning recesses 54a of the lower guide 50, respectively. As a result, the upper guide 60 is unable to rotate relative to the lower guide 50 in the circumferential direction C. The lower guide 50 and the upper guide 60 are stacked in the state shown in FIGS. 6 and 7. Therefore, in the vertical direction Z, the multiple upper sliding surfaces 62a of the upper guide 60 face the multiple lower sliding surfaces 52a of the lower guide 50. More specifically, the upper sliding surfaces 62a of the upper guide 60 are shifted in the circumferential direction C with respect to the lower sliding surfaces 52a of the lower guide 50. In other words, in the vertical direction Z, one upper sliding surface 62a of the upper guide 60 faces two lower sliding surfaces 52a of the lower guide 50. In other words, one lower sliding surface 52a of the lower guide 50 faces two upper sliding surfaces 62a of the upper guide 60.

[0078] 3, 4, and 19, the valve case 70 is stacked on top of the upper guide 60. As shown in FIGS. 3 and 4, the two positioning protrusions 76 of the valve case 70 are inserted into the two positioning recesses 63c of the upper guide 60, respectively. As a result, the valve case 70 is unable to rotate in the circumferential direction C with respect to the upper guide 60.

[0079] As shown in FIG. 2 , two clamps 100 are engaged with the cylinder 40 and the valve case 70. Specifically, the lower ends of the clamps 100 are engaged with the two lower clamp holders 44 and two lower clamp guides 45 of the cylinder 40. Meanwhile, the upper ends of the clamps 100 are engaged with the two upper clamp holders 74 of the valve case 70. In this manner, the two clamps 100 sandwich the stacked cylinder 40, lower guide 50, upper guide 60, and valve case 70 in the vertical direction Z. Here, no sealing member such as packing is disposed between the cylinder 40, lower guide 50, upper guide 60, and valve case 70 that are stacked in the vertical direction Z. Therefore, there are gaps between the cylinder 40, lower guide 50, upper guide 60, and valve case 70 that allow air to pass through.

[0080] As shown in Figures 2 to 4 and 19, the nozzle holder 80 is attached to the upper part of the valve case 70. More specifically, the four locking walls 84 of the nozzle holder 80 are respectively locked onto the four locking protrusions 75 of the valve case 70. That is, the four locking protrusions 75 of the valve case 70 are respectively fitted into the four locking holes 84a of the nozzle holder 80. In this manner, the nozzle holder 80 is attached to the valve case 70 by a so-called snap fit. When the nozzle holder 80 is attached to the valve case 70, the eight upper nozzles 90 are inserted into the eight cylindrical walls 73 of the valve case 70, respectively. In this manner, the eight upper nozzles 90 are connected to the eight connecting flow paths 77 of the valve case 70, respectively.

[0081] 1, the upstream ends of eight connection tubes 22 are connected to the rotary valve 30 via eight upper nozzles 90. As a result, the downstream ends of the eight connection flow paths 77 are connected to eight air bladders 21 via the eight upper nozzles 90 and the eight connection tubes 22, respectively.

[0082] The engagement relationship between the components inside the rotary valve 30 will now be described. As shown in Figures 3, 4, and 19, the lower piston 110 is accommodated in the cylinder 40 and is movable in the vertical direction Z. The lower piston 110 faces the bottom wall 41 of the cylinder 40 in the vertical direction Z. The first seal SL1 of the lower piston 110 contacts the peripheral wall 42 of the cylinder 40. Thus, the lower piston 110, together with the cylinder 40, defines a first air chamber RM1. The first air chamber RM1 is connected to the communication hole 41a and the communication flow path 112a. The lower piston 110 shown in Figure 19 is located at an initial position PL0, which is the lowest position in its range of movement in the vertical direction Z. At the initial position PL0, the lower piston 110 contacts the bottom wall 41 of the cylinder 40. The first air chamber RM1 corresponds to the "air chamber."

[0083] The center piston 120 is accommodated in the cylinder 40, the lower guide 50, and the upper guide 60 and is movable in the up-down direction Z. When the center piston 120 moves up and down, at least a portion of the sliding flange 122 in the circumferential direction C slides on the peripheral wall 42 of the cylinder 40. However, there is a gap between the sliding flange 122 of the center piston 120 and the peripheral wall 42 of the cylinder 40 that is large enough for air to pass through. The center piston 120 is located higher than the lower piston 110. The center piston 120 and the lower piston 110 define a second air chamber RM2. The second air chamber RM2 is connected to the first air chamber RM1 via the communication flow path 112a and is also connected to an internal flow path 126 of the center piston 120. Furthermore, in the state shown in FIG. 19 , the lower piston 110 is separated from the center piston 120, so the second air chamber RM2 is connected to the outside air. Specifically, the second air chamber RM2 is connected to the outside air via the gap between the cylinder 40 and the lower guide 50. The center piston 120 shown in Figure 19 is located at an initial position PC0, which is the lowest position in its range of movement in the vertical direction Z. The second air chamber RM2 corresponds to the "air chamber."

[0084] The lower spring SP1 is disposed between the bottom wall 112 of the lower piston 110 and the sliding flange 122 of the center piston 120 in a state compressed in the vertical direction Z. That is, the lower spring SP1 urges the lower piston 110 and the center piston 120 in directions away from each other. In other words, the lower spring SP1 urges the lower piston 110 in a direction in which the lower piston 110 descends, reducing the volume of the first air chamber RM1. The lower spring SP1 also urges the center piston 120 in a direction in which the center piston 120 rises, increasing the volume of the second air chamber RM2.

[0085] The center spring SP2 is disposed between the sliding flange 122 of the center piston 120 and the intermediate wall 51 of the lower guide 50 in a state compressed in the vertical direction Z. In other words, the center spring SP2 biases the center piston 120 in the direction in which the center piston 120 descends and the volume of the second air chamber RM2 decreases.

[0086] The boss base 130 and the stopper ring 140 are supported by the center piston 120. More specifically, the shaft portion 121 of the center piston 120 is inserted between the boss base 130 and the stopper ring 140. At this time, the boss base 130 contacts the support flange 123 of the center piston 120, and the stopper ring 140 engages with two protrusions 125 of the center piston 120. In this manner, the stopper ring 140, together with the center piston 120, sandwiches the boss base 130 in the vertical direction Z. As a result, the boss base 130 is movable in the vertical direction Z together with the center piston 120. In other words, the boss base 130 is immovable in the vertical direction Z relative to the center piston 120. On the other hand, the boss base 130 is rotatable in the circumferential direction C relative to the center piston 120. The boss base 130 is located radially between the center piston 120 and the lower guide 50 and upper guide 60. Although not shown, the six bosses 131 of the boss base 130 are positioned between the lower sliding surfaces 52a of the lower guide 50 and the upper sliding surfaces 62a of the upper guide 60 in the vertical direction Z.

[0087] The pressing portion 150 is disposed between the upper guide 60 and the valve case 70 with the sliding protrusions 151a facing upward. At this time, the annular plate 151 of the pressing portion 150 is positioned above the intermediate wall 61 of the upper guide 60. As shown in FIGS. 3 and 4, the four locking portions 152 of the pressing portion 150 are locked to the upper guide 60 via the four locking holes 63a. Furthermore, the two engagement pieces 153 of the pressing portion 150 are respectively fitted into the two positioning recesses 63b of the upper guide 60. As a result, the pressing portion 150 is unable to rotate in the circumferential direction C relative to the upper guide 60. The locking portions 152 of the pressing portion 150 are locked to the upper guide 60 by a so-called snap fit.

[0088] As shown in Figures 3, 4, and 19, the pressing spring SP3 is disposed between the intermediate wall 61 of the upper guide 60 and the annular plate 151 of the pressing portion 150 in a state compressed in the vertical direction Z. In other words, the pressing spring SP3 biases the pressing portion 150 upward. Even when the pressing portion 150 is engaged with the upper guide 60, it can be slightly displaced in the vertical direction Z, which is the direction in which the pressing spring SP3 expands and contracts. Note that when assembling the rotary valve 30, the upper guide 60, the pressing portion 150, and the pressing spring SP3 are integrated in advance. As described above, because the four locking portions 152 of the pressing portion 150 are engaged with the upper guide 60, even if the restoring force of the pressing spring SP3 acts on the pressing portion 150, the pressing portion 150 and the upper guide 60 will not separate in the vertical direction Z. That is, the worker assembling the rotary valve 30 can handle the upper guide 60, the pressing portion 150, and the pressing spring SP3 as a single unit.

[0089] The rotary 160 is housed in the upper guide 60 and the valve case 70 so as to be rotatable in the circumferential direction C. A lower shaft portion 172 of the rotary 160 is inserted into the shaft portion 121 of the center piston 120. A third seal SL3 of the rotary 160 contacts the inner circumferential surface of the shaft portion 121 of the center piston 120. In this way, the air intake passage 161 of the rotary 160 is connected to the second air chamber RM2 via the internal passage 126 of the center piston 120.

[0090] The upper shaft portion 173 of the rotary 160 is inserted into the shaft hole 71a of the valve case 70. Thus, the rotary 160 is rotatable in the circumferential direction C relative to the valve case 70 and the center piston 120. As shown in FIGS. 3 and 4 , the two transmission shafts 175 of the rotary 160 are inserted into the two engagement recesses 132 of the boss base 130, respectively. Therefore, the rotary 160 is rotatable in the circumferential direction C together with the center piston 120 and the boss base 130. In other words, the rotary 160 is unable to rotate relative to the center piston 120 and the boss base 130 in the circumferential direction C. Meanwhile, the rotary 160 is movable in the vertical direction Z relative to the center piston 120 and the boss base 130. To be precise, since the rotary 160 is configured to be unable to move in the vertical direction Z, the center piston 120 and the boss base 130 are able to move in the vertical direction Z relative to the rotary 160.

[0091] As shown in Figures 3, 4, 19, and 20, the rotary 160 is covered from above by the valve case 70. Meanwhile, the rotary 160 is pressed against the opening surface 71b of the valve case 70 by a pressing portion 150 that is biased by a pressing spring SP3. Therefore, the fourth seal SL4 of the rotary 160 is compressed and deformed between the retaining groove 195 of the rotary 160 and the opening surface 71b of the valve case 70. Therefore, when the rotary 160 rotates, the fourth seal SL4 of the rotary 160 slides against the opening surface 71b of the valve case 70, and the bottom wall 171 of the rotary 160 slides against the pressing portion 150. The sliding portion 196 of the on-off valve 180 of the rotary 160 is biased radially toward the peripheral wall 72 of the valve case 70. Therefore, when the rotary 160 rotates, the sliding portion 196 of the on-off valve 180 of the rotary 160 slides on the peripheral wall 72 of the valve case 70 .

[0092] <Operation of this embodiment> <Basic operation of rotary valve 30> 20 to 30, the basic operation of the rotary valve 30 when the pump 24 starts to be driven while the rotary valve 30 is in the initial state shown in Fig. 20 will be described. Note that the initial state of the rotary valve 30 shown in Fig. 20 is one example. The initial state of the rotary valve 30 may vary depending on the state of the rotary valve 30 the previous time the pump 24 was stopped from being driven. Also, Figs. 21, 25, and 29 are schematic views showing a portion of the inner circumferential wall 52 of the lower guide 50, a portion of the inner circumferential wall 62 of the upper guide 60, and the boss 131 of the boss base 130.

[0093] 20, in an initial state, the lower piston 110 is located at an initial position PL0, which is the lowest position within its range of movement in the vertical direction Z. The lower piston 110 is in contact with the bottom wall 41 of the cylinder 40 at the initial position PL0.

[0094] In the initial state, the center piston 120 is located at an initial position PC0, which is the lowest position within its range of movement in the vertical direction Z. Therefore, the boss base 130, which moves up and down together with the center piston 120, is also located at the lowest position within its range of movement in the vertical direction Z. As shown in FIG. 21 , in the initial state, the boss 131 of the boss base 130 is in contact with both the lower sliding surface 52a and the lower restricting surface 52b of the lower guide 50. When the boss 131 of the boss base 130 is in contact with both the lower sliding surface 52a and the lower restricting surface 52b of the lower guide 50, the rotary 160 is located at the position shown in FIG. 22 . In other words, because the sliding portion 196 of the on-off valve 180 is in contact with the third sliding surface 72c of the valve case 70, the on-off valve 180 is located at the closed position. In other words, the rotary 160 is in an air supply state in which the exhaust passage 162 is not connected to the outside air.

[0095] As shown in FIG. 20 , in the initial state, the second air chamber RM2 is connected to one air bag 21h via the internal flow path 126 of the center piston 120, the air intake flow path 161 of the rotary 160, the connecting flow path 77h of the valve case 70, the upper nozzle 90, and the connecting tube 22. Because the on-off valve 180 of the rotary 160 is in the closed position, the air intake flow path 161 of the rotary 160 is not connected to the outside air. On the other hand, because the lower piston 110 is not in contact with the center piston 120, the second air chamber RM2 is connected to the outside air. Therefore, in the initial state, the air bag 21h is connected to the outside air, and the pressure in the air bag 21h is equal to the outside air pressure. In other words, in the initial state, the air bag 21h is contracted. Also, in the initial state, the biasing force of the lower spring SP1 on the lower piston 110 is smaller than the biasing force of the center spring SP2 on the center piston 120.

[0096] As shown by the solid arrow in Figure 20, when the pump 24 is driven, air begins to be supplied to the first air chamber RM1 through the communication hole 41a of the cylinder 40. Then, air is supplied from the first air chamber RM1 to the second air chamber RM2 through the communication flow path 112a of the lower piston 110. Because the inner diameter of the communication flow path 112a of the lower piston 110 is small, the flow rate of air flowing into the second air chamber RM2 through the communication flow path 112a is smaller than the flow rate of air flowing into the first air chamber RM1 through the communication hole 41a. In other words, the communication flow path 112a of the lower piston 110 limits the flow rate of air flowing from the first air chamber RM1 to the second air chamber RM2. Therefore, the pressure in the first air chamber RM1 increases over time after the pump 24 is driven. On the other hand, the air supplied to the second air chamber RM2 is discharged to the outside air through the gap between the lower piston 110 and the center piston 120 and the gap between the cylinder 40 and the lower guide 50. Therefore, the pressure in the second air chamber RM2 does not increase substantially.

[0097] In this embodiment, since the inner diameter of the communication hole 41a of the cylinder 40 is small, the flow rate of air flowing into the first air chamber RM1 through the communication hole 41a is smaller than the flow rate of air delivered by the pump 24. In other words, the communication hole 41a of the cylinder 40 limits the flow rate of air flowing into the first air chamber RM1.

[0098] As the pressure in the first air chamber RM1 increases, the upward force acting on the lower piston 110 becomes greater than the downward force acting on the lower piston 110, causing the lower piston 110 to begin to rise. Here, the upward force acting on the lower piston 110 is the product of the pressure in the first air chamber RM1 and the pressure-receiving area of ​​the lower piston 110 on which the pressure acts. On the other hand, the downward force acting on the lower piston 110 is the sum of the product of the pressure in the second air chamber RM2 and the pressure-receiving area of ​​the lower piston 110 on which the pressure acts, and the biasing force of the lower spring SP1.

[0099] 23, when the lower piston 110 rises, the second seal SL2 of the lower piston 110 comes into contact with the sliding flange 122 of the center piston 120. When the lower piston 110 then rises further, the second seal SL2 of the lower piston 110 is compressed. In other words, the second seal SL2 of the lower piston 110 comes into close contact with the sliding flange 122 of the center piston 120. As a result, the second air chamber RM2 is sealed off from the outside air.

[0100] When the lower piston 110 contacts the center piston 120, the air flowing into the second air chamber RM2 is prevented from flowing out to the outside air. As a result, the air flowing into the second air chamber RM2 is supplied to one air bladder 21h via the internal flow path 126 of the center piston 120, the air intake flow path 161 of the rotary 160, the connecting flow path 77h of the valve case 70, the upper nozzle 90, and the connecting tube 22. That is, the air bladder 21h expands. Furthermore, the pressures of the first air chamber RM1 and the second air chamber RM2 increase, and the pressures of the spaces and flow paths connected to the second air chamber RM2 also increase. As described above, the communication flow path 112a of the lower piston 110 limits the flow rate of air flowing from the first air chamber RM1 to the second air chamber RM2. Therefore, the pressure of the first air chamber RM1 is maintained higher than the pressure of the second air chamber RM2.

[0101] 24, as the pressure in the first air chamber RM1 increases, the upward force acting on the lower piston 110 and the center piston 120 becomes greater than the downward force acting on the lower piston 110 and the center piston 120, causing the lower piston 110 to rise together with the center piston 120. Here, the upward force acting on the lower piston 110 and the center piston 120 is the product of the pressure in the first air chamber RM1 and the pressure-receiving area of ​​the lower piston 110 on which the pressure acts. On the other hand, the downward force acting on the lower piston 110 and the center piston 120 is the biasing force of the center spring SP2. When the center piston 120 rises, the boss base 130 rises together with the center piston 120.

[0102] 25, when the boss base 130 rises, the boss 131 of the boss base 130 transitions from a state in which it engages with the lower guide 50 to a state in which it engages with the upper guide 60. More specifically, as indicated by the two-dot chain arrow in FIG. 25, the state in which the lower cam surface 131a of the boss base 130 contacts the lower sliding surface 52a of the lower guide 50 changes to a state in which the upper cam surface 131b of the boss base 130 contacts the upper sliding surface 62a of the upper guide 60. If the center piston 120 continues to rise even after the upper cam surface 131b of the boss base 130 contacts the upper sliding surface 62a of the upper guide 60, the upper cam surface 131b of the boss base 130 slides against the upper sliding surface 62a of the upper guide 60, as indicated by the solid arrow in FIG. 25. In other words, the boss base 130 rotates in the first circumferential direction C1 while rising.

[0103] When the boss base 130 rotates, the rotary 160 rotates together with the boss base 130. When the boss 131 of the boss base 130 moves to the position shown by the solid line in Fig. 25, the rotary 160 rotates to the position shown in Fig. 26. In this way, the rotary 160 rotates in the first circumferential direction C1 when the pressure in the first air chamber RM1 and the pressure in the second air chamber RM2 increase.

[0104] 25, when the upper cam surface 131b of the boss base 130 slides against the upper sliding surface 62a of the upper guide 60, the engagement relationship between the sliding portion 196 of the on-off valve 180 and the valve case 70 changes as shown in FIG. 26. More specifically, the sliding portion 196 of the on-off valve 180 changes from a state in which it faces the third sliding surface 72c of the valve case 70 to a state in which it faces the first sliding surface 72a, which is positioned offset from the third sliding surface 72c in the first circumferential direction C1. At this time, the on-off valve 180 slides against the third sliding surface 72c as the rotary 160 rotates in the first circumferential direction C1.

[0105] The third sliding surface 72c is a curved surface along the circumferential direction C, and is a curved surface close to the rotation axis of the rotary 160. Therefore, when the sliding portion 196 of the on-off valve 180 slides against the third sliding surface 72c, the on-off valve 180 is maintained in the closed position. As the rotary 160 rotates in the first circumferential direction C1, when the sliding portion 196 of the on-off valve 180 no longer slides against the third sliding surface 72c, the on-off valve 180 rotates in the open direction due to the restoring force of the torsion spring 200. In other words, the on-off valve 180 is displaced from the closed position to the open position. In this way, when the center piston 120 rises, the rotary 160 switches from the air supply state to the exhaust state in which the exhaust passage 162 is connected to the outside air. The rotary 160 switches from the air supply state to the exhaust state before the boss 131 of the boss base 130 comes into contact with the upper regulating surface 62b of the upper guide 60.

[0106] As shown in FIG. 24, even when the on-off valve 180 is in the open position, the air intake passage 161 of the rotary 160 is connected to the connecting passage 77h of the valve case 70. That is, in FIG. 26, the connecting passage 77h is located inside the fourth seal SL4 of the rotary 160. Therefore, the air intake passage 161 of the rotary 160 is connected to the air bladder 21h. As a result, air is discharged from the second air chamber RM2 to the outside air, and air is also discharged from the air bladder 21h to the outside air. The air discharged from the exhaust passage 162 of the rotary 160 is discharged to the outside air through the gap between the upper guide 60 and the valve case 70. As a result, the pressure in the second air chamber RM2 decreases, and the air bladder 21h contracts. Furthermore, as the pressure in the second air chamber RM2 decreases, the pressure in the first air chamber RM1 also decreases.

[0107] 27, as the pressure in the first air chamber RM1 decreases, the downward force acting on the lower piston 110 and the center piston 120 becomes greater than the upward force acting on the lower piston 110 and the center piston 120, causing the lower piston 110 to descend together with the center piston 120. Here, the upward force acting on the lower piston 110 and the center piston 120 is the product of the pressure in the first air chamber RM1 and the pressure-receiving area of ​​the lower piston 110 on which the pressure acts. On the other hand, the downward force acting on the lower piston 110 and the center piston 120 is the biasing force of the center spring SP2. When the center piston 120 descends, the boss base 130 descends together with the center piston 120.

[0108] As shown in FIG. 28 , when the boss base 130 descends, the boss 131 of the boss base 130 transitions from a state in which it engages with the upper guide 60 to a state in which it engages with the lower guide 50. More specifically, as indicated by the two-dot chain arrow in FIG. 28 , the state in which the upper cam surface 131b of the boss base 130 contacts the upper sliding surface 62a of the upper guide 60 transitions to a state in which the lower cam surface 131a of the boss base 130 contacts the lower sliding surface 52a of the lower guide 50. If the center piston 120 continues to descend even after the lower cam surface 131a of the boss base 130 contacts the lower sliding surface 52a of the lower guide 50, the lower cam surface 131a of the boss base 130 slides against the lower sliding surface 52a of the lower guide 50, as indicated by the solid arrow in FIG. 28 . In other words, the boss base 130 rotates in the first circumferential direction C1 while descending.

[0109] When the boss base 130 rotates, the rotary 160 rotates together with the boss base 130. When the boss 131 of the boss base 130 moves to the position shown by the solid line in Fig. 28, the rotary 160 rotates to the position shown in Fig. 29. In this way, the rotary 160 rotates in the first circumferential direction C1 when the pressure in the first air chamber RM1 and the pressure in the second air chamber RM2 decrease.

[0110] 28, when the lower cam surface 131a of the boss base 130 slides against the lower sliding surface 52a of the lower guide 50, the engagement relationship between the sliding portion 196 of the on-off valve 180 and the valve case 70 changes as shown in FIG. 29. Specifically, the sliding portion 196 of the on-off valve 180 changes from a state in which it faces the first sliding surface 72a of the valve case 70 to a state in which it faces the third sliding surface 72c that is positioned offset from the first sliding surface 72a in the first circumferential direction C1. At this time, the sliding portion 196 of the on-off valve 180 slides against the first sliding surface 72a, the second sliding surface 72b, and the third sliding surface 72c as the rotary 160 rotates in the first circumferential direction C1.

[0111] The first sliding surface 72a is a curved surface that extends along the first circumferential direction C1 and is far from the rotation axis of the rotary 160. Therefore, when the sliding portion 196 of the on-off valve 180 slides against the first sliding surface 72a, the on-off valve 180 is maintained in the open position. Next, the second sliding surface 72b is an inclined surface that slopes toward the rotation axis of the rotary 160 as it advances in the first circumferential direction C1. Therefore, when the sliding portion 196 of the on-off valve 180 slides against the second sliding surface 72b, the on-off valve 180 rotates in the closing direction. The on-off valve 180 completes its displacement to the closed position while the sliding portion 196 of the on-off valve 180 is sliding against the second sliding surface 72b. Next, the third sliding surface 72c is a curved surface that extends along the first circumferential direction C1 and is close to the rotation axis of the rotary 160. Therefore, when the sliding portion 196 of the on-off valve 180 slides against the third sliding surface 72c, the on-off valve 180 is maintained in the closed position. Thus, when the center piston 120 descends, the rotary 160 switches from the exhaust state to the intake state. Note that the rotary 160 switches from the exhaust state to the intake state before the boss 131 of the boss base 130 comes into contact with the lower restriction surface 52b of the lower guide 50.

[0112] When the boss 131 moves to the position indicated by the solid line in FIG. 28 as the center piston 120 descends, the air intake passage 161 of the rotary 160 is no longer connected to the connecting passage 77h of the valve case 70, as shown in FIGS. 27 and 29. That is, in FIG. 29, the connecting passage 77h is no longer positioned inside the fourth seal SL4 of the rotary 160. As a result, the air intake passage 161 of the rotary 160 is no longer connected to the air bladder 21h via the connecting passage 77h. Meanwhile, as shown in FIGS. 29 and 30, the air intake passage 161 of the rotary 160 is connected to the connecting passage 77a of the valve case 70. That is, in FIG. 29, the connecting passage 77a is positioned inside the fourth seal SL4 of the rotary 160. As a result, the air intake passage 161 of the rotary 160 is connected to the next air bladder 21a via the connecting passage 77a.

[0113] 27 and 30 are generally the same state, except that the rotary 160 has rotated slightly less than 45° in the first circumferential direction C1 from the state shown in FIG. 23. Therefore, if the pump 24 continues to be driven in the state shown in FIG. 27, the air bladder 21a will inflate and then deflate. If the pump 24 continues to be driven thereafter, the air bladder 21b will inflate and then deflate. In this manner, the rotary valve 30 sequentially switches between the air bladders 21 that are inflated and deflated. As described above, in the rotary valve 30, the rotary 160 sequentially switches between the air supply state and the air exhaust state for the eight air bladders 21 during one rotation. In other words, the rotary 160 sequentially switches between 16 states during one rotation.

[0114] <Effects when the pump 24 is stopped> The operation of the rotary valve 30 when the driving of the pump 24 is stopped will be described with reference to FIGS.

[0115] As described above, when air is supplied from the pump 24 to the rotary valve 30, the on-off valve 180 repeatedly moves between the closed position and the open position. Therefore, depending on the timing at which the driving of the pump 24 is stopped, the on-off valve 180 may be in the closed position or in the open position. The driving of the pump 24 may be stopped when the user turns off the ignition of the vehicle or when the user ends the massage by the air pressure system 20. In this respect, the timing at which the driving of the pump 24 is stopped is independent of the position of the on-off valve 180.

[0116] For example, if the supply of air from pump 24 is stopped while on-off valve 180 is in the closed position, air will no longer be discharged from air bag 21 connected to air intake path 161 of rotary 160. That is, air bag 21 communicating with air intake path 161 of rotary 160 will remain inflated. In this case, there is a risk that the user sitting in seat 10 will become uncomfortable. Furthermore, if air bag 21 remains inflated for a long period of time, there is a risk that air bag 21 will be more susceptible to deterioration over time. Therefore, in the above case, rotary valve 30 discharges air from air bag 21 as follows.

[0117] 31 shows a state in which the on-off valve 180 of the rotary 160 is in the closed position, an air bag 21 is inflated, and the operation of the pump 24 is stopped. Immediately after the operation of the pump 24 is stopped, the pressure in the first air chamber RM1 and the pressure in the second air chamber RM2 are relatively high, and the pressure in the first air chamber RM1 is higher than the pressure in the second air chamber RM2. In addition, because the lower piston 110 is in contact with the center piston 120, the second air chamber RM2 is cut off from the outside air.

[0118] If we consider the lower piston 110 and the center piston 120 as being integral with each other, the upward force acting on these pistons is balanced with the downward force acting on these pistons. In other words, the product of the pressure in the first air chamber RM1 and the pressure-receiving area of ​​the lower piston 110 on which this pressure acts is equal to the biasing force of the center spring SP2 on the center piston 120.

[0119] Furthermore, when the lower piston 110 is considered to be a separate body from the center piston 120, the upward force acting on the lower piston 110 is greater than the downward force acting on the lower piston 110. In other words, the product of the pressure in the first air chamber RM1 and the pressure-receiving area of ​​the lower piston 110 on which the pressure acts is greater than the sum of the product of the pressure in the second air chamber RM2 and the pressure-receiving area of ​​the lower piston 110 on which the pressure acts, and the biasing force of the lower spring SP1.

[0120] Furthermore, when the center piston 120 is considered to be a separate component from the lower piston 110, the upward force acting on the center piston 120 is smaller than the downward force acting on the center piston 120. In other words, the sum of the product of the pressure in the second air chamber RM2 and the pressure-receiving area of ​​the center piston 120 on which the pressure acts and the biasing force of the lower spring SP1 is smaller than the biasing force of the center spring SP2.

[0121] As time passes after the driving of the pump 24 is stopped, air flows from the first air chamber RM1 to the second air chamber RM2, as indicated by the solid arrow in Figure 31. As a result, the pressure difference between the first air chamber RM1 and the second air chamber RM2 decreases. When the pressure difference between the first air chamber RM1 and the second air chamber RM2 decreases, the upward force acting on the lower piston 110 decreases and the downward force acting on the lower piston 110 increases. The upward force acting on the lower piston 110 becomes smaller than the downward force acting on the lower piston 110. As a result, as shown in Figure 32, the lower piston 110 moves slightly downward relative to the center piston 120. In other words, as the lower piston 110 moves away from the center piston 120, the second air chamber RM2 is connected to the outside air.

[0122] When the second air chamber RM2 is connected to the outside air, as shown by the solid arrow in Figure 32, air is discharged from the second air chamber RM2 to the outside air, reducing the pressure in the second air chamber RM2. This reduces the downward force acting on the lower piston 110. As a result, the speed at which the lower piston 110 descends slows or the lower piston 110 stops. Also, the upward force acting on the center piston 120 decreases. As a result, the center piston 120 descends until it comes into contact with the lower piston 110. In other words, the second air chamber RM2 is again isolated from the outside air.

[0123] While the lower piston 110 and the center piston 120 are descending, the pressure in the first air chamber RM1 remains higher than the pressure in the second air chamber RM2. Therefore, air flows from the first air chamber RM1 to the second air chamber RM2, reducing the pressure difference between the first air chamber RM1 and the second air chamber RM2. That is, as described above, after the lower piston 110 descends, the center piston 120 also descends, following the lower piston 110. In this way, the lower piston 110 and the center piston 120 descend while repeatedly coming into contact with and separating from each other.

[0124] When the center piston 120 descends, the boss base 130 descends along with the center piston 120. That is, the engagement relationship between the boss base 130 and the lower guide 50 changes, as in the case shown in FIG. 28 . Therefore, the boss base 130 descends without rotating in the circumferential direction C until the boss 131 of the boss base 130 contacts any of the lower sliding surfaces 52a of the lower guide 50. Subsequently, after the boss 131 of the boss base 130 contacts any of the lower sliding surfaces 52a of the lower guide 50, the boss base 130 descends while rotating in the first circumferential direction C1. As a result, the rotary 160 switches from the air supply state to the air exhaust state. Therefore, air is discharged from the second air chamber RM2 and the air bag 21.

[0125] As the center piston 120 continues to descend, the boss 131 of the boss base 130 comes into contact with both the lower sliding surface 52a and the lower restriction surface 52b of the lower guide 50, and the center piston 120 finishes descending to the initial position PC0. Therefore, after the center piston 120 has descended to the initial position PC0, the lower piston 110 descends relative to the center piston 120. In this way, the lower piston 110 descends to the initial position PL0. As described above, even when the rotary 160 is in the air supply state and the driving of the pump 24 is stopped, the air bag 21 is not left in an inflated state.

[0126] <Effects of this embodiment> 22, 26, and 29, the on-off valve 180 rotates between the closed position and the open position by sliding against the first sliding surface 72a, the second sliding surface 72b, and the third sliding surface 72c of the valve case 70. In other words, the on-off valve 180 is easily displaced between the closed position and the open position by the force acting due to sliding against the first sliding surface 72a, the second sliding surface 72b, and the third sliding surface 72c of the valve case 70. Therefore, the rotary valve 30 can smoothly displace the on-off valve 180 between the closed position and the open position.

[0127] (2) In order to efficiently rotate the on-off valve 180 from the open position to the closed position, it is important to increase the proportion of the component that contributes to the rotation of the on-off valve 180 out of the force acting on the on-off valve 180 due to sliding on the second sliding surface 72b of the valve case 70. In this regard, in the rotary valve 30, the rotation axis of the link arm 190 is located further in the first circumferential direction C1, which is the direction of movement associated with the rotation of the rotary 160, than the sliding part 196. Therefore, the proportion of the component that contributes to the rotation of the on-off valve 180 is likely to be higher than in the comparative example in which the sliding part 196 is located further in the direction of movement associated with the rotation of the rotary 160 than the rotation axis of the link arm 190. In this way, the rotary valve 30 can efficiently rotate the on-off valve 180 from the open position to the closed position.

[0128] (3) The rotary valve 30 has a torsion spring 200 that biases the on-off valve 180 in the opening direction. Therefore, the rotary valve 30 can stabilize the rotation of the on-off valve 180 from the closed position toward the open position.

[0129] (4) Consider the case where the on-off valve 180 and the torsion spring 200 are assembled to a predetermined position on the rotary 160. In this case, the worker first passes the coil portion 201 of the torsion spring 200 through the link support shaft 177, and then engages the first arm 202 and the second arm 203 of the torsion spring 200 with the first engagement shaft 178 and the second engagement shaft 179 of the rotary 160, respectively. Next, the on-off valve 180 is passed through the link support shaft 177, thereby supporting the on-off valve 180 on the link support shaft 177.

[0130] Here, when the on-off valve 180 is rotated to the maximum in the opening direction, the second arm 203 of the torsion spring 200 comes into contact with the second engagement shaft 179 of the rotary 160. On the other hand, when the on-off valve 180 is rotated in the closing direction, which is the direction from the open position toward the closed position, the second arm 203 of the torsion spring 200 moves away from the second engagement shaft 179 of the rotary 160 and engages with the link arm 190. In other words, the torsion spring 200 biases the link arm 190 in the opening direction.

[0131] The rotary valve 30 allows the work of assembling the torsion spring 200 to the rotary 160 and the work of assembling the on-off valve 180 to the rotary 160 to be performed separately. In other words, the spring assembling process and the on-off valve assembling process can be performed separately for the rotary valve 30. Therefore, the assembling worker does not need to simultaneously assemble the torsion spring 200 and the on-off valve 180 to the rotary 160 while elastically deforming the torsion spring 200.

[0132] (5) Consider a case where a valve case 70 is stacked on an upper guide 60 in a manufacturing process of a rotary valve 30. In this case, the valve case 70 is stacked on the upper guide 60 with the rotary 160 housed in the lower guide 50. Here, if the position of the sliding portion 196 of the on-off valve 180 of the rotary 160 and the position of the first sliding surface 72a of the valve case 70 are aligned in the circumferential direction C, the valve case 70 will not interfere with the on-off valve 180 when stacking the valve case 70 on the upper guide 60. On the other hand, if the position of the sliding portion 196 of the on-off valve 180 of the rotary 160 and the position of the second sliding surface 72b or the third sliding surface 72c of the valve case 70 are aligned in the circumferential direction C, the valve case 70 will interfere with the on-off valve 180 when stacking the valve case 70 on the upper guide 60. However, a pressure-receiving surface 196b of the sliding portion 196, which is the portion of the on-off valve 180 of the rotary 160 that interferes with the valve case 70, is inclined with respect to the vertical direction Z. For this reason, when the valve case 70 is pressed against the pressure-receiving surface 196b of the sliding portion 196, a torque is generated that rotates the on-off valve 180 in the closing direction. Therefore, when stacking the valve case 70 on the upper guide 60, it is no longer necessary to rotate the on-off valve 180 in the closing direction using a jig or the like.

[0133] (6) When the rotary 160 rotates, the sliding portion 196 of the on-off valve 180 slides against the first sliding surface 72a, the second sliding surface 72b, and the third sliding surface 72c of the valve case 70. In this embodiment, the inclination of the second sliding surface 72b with respect to the first circumferential direction C1 is relatively large. In other words, at the portion where the first sliding surface 72a and the second sliding surface 72b connect, the angle formed between the tangent direction of the first sliding surface 72a and the second sliding surface 72b is relatively large. Therefore, even if variations occur in the inclination of the second sliding surface 72b due to manufacturing errors in the valve case 70, the variations are unlikely to affect the position of the on-off valve 180. Specifically, even if variations occur in the inclination of the second sliding surface 72b, the rotational position of the on-off valve 180 is likely to be uniquely determined with respect to the rotational position of the rotary 160. Therefore, the rotary valve 30 can improve the accuracy of opening and closing the exhaust port 162a of the rotary 160 relative to the rotational position of the rotary 160 when the rotary 160 rotates.

[0134] (7) Even if the driving of the pump 24 is stopped while the rotary 160 is in the air supply state, the rotary valve 30 can lower the lower piston 110 and the center piston 120. In other words, the rotary valve 30 can deflate the air bag 21 by connecting the second air chamber RM2 to the outside air.

[0135] (8) Consider a modified example in which the cylinder 40 is configured with a lower cylinder and an upper cylinder that are divided into upper and lower halves. In this case, it is possible to define the first air chamber RM1 between the lower cylinder and the lower piston 110, and define the second air chamber RM2 between the upper cylinder, the lower piston 110, and the center piston 120. However, in this modified example, the rotary valve 30 tends to be longer in the vertical direction Z because the number of layers stacked in the vertical direction Z increases. In contrast, in the rotary valve 30 of this embodiment, the second air chamber RM2 is defined by the lower piston 110 and the center piston 120. Therefore, the length of the rotary valve 30 in the vertical direction Z tends to be shorter.

[0136] (9) The biasing force of the lower spring SP1 on the lower piston 110, which is located in the initial position PL0, is smaller than the biasing force of the center spring SP2 on the center piston 120, which is located in the initial position PC0. Therefore, the rotary valve 30 can quickly raise the lower piston 110 after the pump 24 starts to be driven. In other words, the rotary valve 30 can quickly inflate the air bag 21 after the pump 24 starts to be driven.

[0137] (10) The lower spring SP1 is disposed inside the second air chamber RM2, between the lower piston 110 and the center piston 120. Therefore, the rotary valve 30 can efficiently accommodate the lower spring SP1.

[0138] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0139] In the rotary 160, the torsion spring 200 may have any configuration as long as it can bias the on-off valve 180. For example, the torsion spring 200 may be a coil spring. The torsion spring 200 may also be a biasing member that utilizes the elasticity of rubber or the like.

[0140] When the on-off valve 180 is in the closed position, a force corresponding to the pressure in the exhaust flow path 162 acts on the valve element 181 of the on-off valve 180. Therefore, a torque that rotates the on-off valve 180 in the opening direction acts on the on-off valve 180. Therefore, the on-off valve 180 can be displaced from the closed position to the open position even without the torsion spring 200.

[0141] The position of the rotation axis of the on-off valve 180 can be changed as appropriate in the rotary 160. For example, the rotation axis of the on-off valve 180 may be located behind the sliding portion 196 of the on-off valve 180 in the direction of travel associated with the rotation of the rotary 160.

[0142] In the rotary 160 , the rotation axis of the on-off valve 180 may be slightly tilted with respect to the rotation axis of the rotary 160 . The shapes and locations of the lower spring SP1 and the center spring SP2 may be changed as appropriate. For example, the lower spring SP1 may be arranged in the first air chamber RM1 in an expanded state.

[0143] When the rotary valve 30 is designed to move downwards when the rotary valve 160 switches from the intake state to the exhaust state while the pump 24 is continuously driven, the manner in which the lower piston 110 moves downwards can be selected appropriately.

[0144] For example, when the inner diameter of the communication passage 112a of the lower piston 110 is small, the pressure difference between the first air chamber RM1 and the second air chamber RM2 increases, resulting in a larger upward force acting on the lower piston 110. Also, when the inner diameter of the communication hole 41a of the cylinder 40 is large, the pressure difference between the first air chamber RM1 and the second air chamber RM2 increases, resulting in a larger upward force acting on the lower piston 110. Furthermore, when the biasing force of the lower piston 110 is small, the downward force acting on the lower piston 110 decreases. Therefore, in such a case, the lower piston 110 is more likely to maintain contact with the center piston 120. As a result, when the rotary 160 is in the exhaust state, the lower piston 110 is more likely to descend while remaining in contact with the center piston 120.

[0145] On the other hand, when the inner diameter of the communication flow passage 112a of the lower piston 110 is large, the pressure difference between the first air chamber RM1 and the second air chamber RM2 is small, and therefore the upward force acting on the lower piston 110 is small. Also, when the inner diameter of the communication hole 41a of the cylinder 40 is small, the pressure difference between the first air chamber RM1 and the second air chamber RM2 is small, and therefore the upward force acting on the lower piston 110 is small. Furthermore, when the biasing force of the lower piston 110 is large, the downward force acting on the lower piston 110 is large. Therefore, in such a case, the lower piston 110 is likely to separate from the center piston 120. In reality, when the rotary 160 is in the exhaust state, the lower piston 110 and the center piston 120 are likely to descend while repeatedly coming into contact with and separating from each other.

[0146] The air pressure system 20 can be installed not only in the seat 10 but also in a bed, a mattress, etc. <Summary of this embodiment> The rotary valve is a rotary valve that sequentially inflates and deflates a plurality of air bladders by switching the air supply mode to the plurality of air bladders, and includes a case that has a plurality of connecting flow paths whose downstream ends are connected to the plurality of air bladders, respectively, and that defines an air chamber to which air is supplied from a pump; a center piston that rises as the pressure in the air chamber increases and descends as the pressure in the air chamber decreases; an air intake flow path that is located above the center piston and connected to the air chamber; and an exhaust flow path that connects the air intake flow path to outside air, and in response to the rise and fall of the center piston: and a rotary that rotates around an axis extending in the vertical direction to sequentially switch the connection flow paths that are connected to the air intake flow path, wherein the rotary further has an on-off valve that moves between a closed position that closes an exhaust port, which is an opening in the exhaust flow path that connects to the outside air, and an open position that opens the exhaust port while the air intake flow path is connected to one of the connection flow paths, and the case further has a sliding surface whose distance to the rotation axis of the rotary changes in the rotation direction of the rotary, and the on-off valve moves between the closed position and the open position while rotating by sliding against the sliding surface of the case as the rotary rotates.

[0147] The rotary valve rotates the rotary in response to the up and down movement of the center piston due to increases and decreases in the pressure of the air chamber. The rotary valve sequentially switches the connecting flow paths of the case to which the rotary's air intake flow path is connected as the rotary rotates. In this way, the rotary valve sequentially inflates and deflates multiple air bladders. The rotary also has an on-off valve that opens and closes the exhaust port in response to the rotation of the rotary while the air intake flow path is connected to one connecting flow path. When the on-off valve is in the closed position, the air intake flow path is not connected to the outside air. In this state, the center piston rises as the pressure in the air chamber increases, and air is supplied to the air bladders connected to the air intake flow path. On the other hand, when the on-off valve is in the open position, the air intake flow path is connected to the outside air. In this state, the center piston descends as the pressure in the air chamber decreases, and air is exhausted from the air bladders connected to the air intake flow path. The on-off valve rotates between the closed and open positions by sliding against the sliding surface of the case. In other words, the on-off valve is easily displaced between the closed and open positions by the force acting from sliding against the sliding surface of the case, and therefore the rotary valve allows the on-off valve to smoothly move between the closed and open positions.

[0148] In the above rotary valve, the on-off valve includes a sliding part that slides against the sliding surface of the case, a link arm that is rotatably supported on the rotary, and a valve body that is held by the link arm and opens and closes the exhaust port, and when the rotary is viewed from above and below, it is preferable that the axis of rotation of the link arm is located in the direction of travel associated with the rotation of the rotary, rather than the sliding part.

[0149] In order to efficiently rotate the on-off valve from the open position to the closed position, it is important to increase the proportion of the component that contributes to the rotation of the on-off valve out of the force acting on the on-off valve due to sliding on the sliding surface of the case. In this regard, in the rotary valve with the above configuration, the rotation axis of the link arm is located further in the direction of movement associated with rotation of the rotary than the sliding portion. Therefore, the proportion of the component that contributes to the rotation of the on-off valve is higher than in the comparative example in which the sliding portion is located further in the direction of movement associated with rotation of the rotary than the rotation axis of the link arm. Therefore, the rotary valve can efficiently rotate the on-off valve from the open position to the closed position.

[0150] In the rotary valve, it is preferable that the rotary further includes a biasing member that biases the on-off valve in a direction from the closed position toward the open position. The rotary valve can stabilize the sliding between the on-off valve and the sliding surface of the case, and can stabilize the rotation of the on-off valve toward the open position.

[0151] In the above rotary valve, the biasing member is a torsion spring including a coil portion, a first arm extending from a first end of the coil portion, and a second arm extending from a second end of the coil portion, and the rotary further has a link support shaft supporting the link arm and the coil portion of the torsion spring, a first arm engaging portion with which the first arm of the torsion spring can engage, and a second arm engaging portion with which the second arm of the torsion spring can engage, and the torsion spring biases the on-off valve by engaging the first arm with the first arm engaging portion and the second arm with the link arm, and it is preferable that the second arm of the torsion spring moves away from the link arm and engages with the second arm engaging portion when the on-off valve rotates in the opening direction from the closed position toward the open position, and moves away from the second arm engaging portion and engages with the link arm when the on-off valve rotates in the closing direction from the open position toward the closed position.

[0152] When assembling the on-off valve and torsion spring at a predetermined position on the rotary, the worker first passes the coil portion of the torsion spring through the link support shaft and engages the first and second arms of the torsion spring with the first arm engaging portion and the second arm engaging portion of the rotary, respectively. Next, the on-off valve is passed through the link support shaft, thereby supporting the on-off valve on the link support shaft. When the on-off valve is rotated in the opening direction, the second arm of the torsion spring engages with the second arm engaging portion and disengages from the link arm. On the other hand, when the on-off valve is rotated in the closing direction, the second arm of the torsion spring engages with the link arm and disengages from the second arm engaging portion. In other words, the torsion spring biases the on-off valve in the opening direction. Therefore, the rotary valve assembler does not need to simultaneously assemble the torsion spring and the on-off valve to the rotary while elastically deforming the torsion spring. [Explanation of symbols]

[0153] 20... Pneumatic system, 21... Air bag, 24... Pump, 30... Rotary valve, 40... Cylinder (case), 41a... Communication hole, 50... Lower guide (case), 60... Upper guide (case), 70... Valve case (case), 71b... Opening surface, 72a... First sliding surface (sliding surface), 72b... Second sliding surface (sliding surface), 72c... Third sliding surface (sliding surface), 72d... Connection surface, 77 (77a to 77h)... Connection flow path, 80... Nozzle holder, 90... Upper nozzle, 110... Lower piston, 112a... Communication flow path, 120... Center piston, 126... Internal flow path, 130... Boss base, 140... Stopper ring, 150... Pressing portion, 1 60...rotary, 161...air intake passage, 162...exhaust passage, 162a...exhaust port, 170...rotary body, 177...link support shaft, 178...first engagement shaft (first arm engagement shaft), 179...second engagement shaft (second arm engagement shaft), 180...opening / closing valve, 181...valve body, 190...link arm, 191...arm body, 196...sliding portion, 200...torsion spring, 201...coil portion, 202...first arm, 203...second arm, Z...vertical direction, RM1...first air chamber (air chamber), RM2...second air chamber (air chamber), SP1...lower spring, SP2...center spring, C (C1, C2)...circumferential direction (first circumferential direction, second circumferential direction)

Claims

1. A rotary valve that sequentially inflates and deflates a plurality of air bladders by switching an air supply mode for the plurality of air bladders, a case having a plurality of connecting flow paths whose downstream ends are connected to the plurality of air bags respectively, and defining an air chamber to which air is supplied from a pump; a center piston that rises as the pressure in the air chamber increases and descends as the pressure in the air chamber decreases; a rotary located above the center piston, the rotary having an air intake passage connected to the air chamber and an exhaust passage connecting the air intake passage with outside air, the rotary rotating about an axis extending in a vertical direction in response to the rise and fall of the center piston to sequentially switch the connecting passages connected to the air intake passage, the rotary further includes an on-off valve that is displaced between a closed position that closes an exhaust port, which is an opening in the exhaust flow path that connects to outside air, and an open position that opens the exhaust port, while the air intake flow path is connected to one of the connection flow paths; the case further includes a sliding surface whose distance to the rotation axis of the rotary changes with respect to the rotation direction of the rotary; The on-off valve is displaced while rotating between the closed position and the open position by sliding on the sliding surface of the case as the rotary rotates. Rotary valve.

2. The on-off valve is a link arm including a sliding portion that slides on the sliding surface of the case and is rotatably supported by the rotary; a valve body held by the link arm and configured to open and close the exhaust port, When the rotary is viewed from above, the rotation axis of the link arm is located further in the direction of travel of the rotary than the sliding portion.

2. The rotary valve according to claim 1.

3. The rotary further includes a biasing member that biases the on-off valve in a direction from the closed position toward the open position.

3. The rotary valve according to claim 2.

4. the biasing member is a torsion spring including a coil portion, a first arm extending from a first end of the coil portion, and a second arm extending from a second end of the coil portion; the rotary further includes a link support shaft that supports the link arm and the coil portion of the torsion spring, a first arm engaging portion with which the first arm of the torsion spring can be engaged, and a second arm engaging portion with which the second arm of the torsion spring can be engaged, the torsion spring biases the on-off valve by engaging the first arm with the first arm engaging portion and by engaging the second arm with the link arm, The second arm of the torsion spring moves away from the link arm and engages with the second arm engaging portion when the on-off valve rotates in an opening direction from the closed position toward the open position, and moves away from the second arm engaging portion and engages with the link arm when the on-off valve rotates in a closing direction from the open position toward the closed position.

4. The rotary valve according to claim 3.

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