Flow path switching device

Abstract

To suppress the slide wear and come-off caused by hooking at the rotation of a drive disc, in a seal member arranged between a fixed disc and the drive disc.SOLUTION: A flow passage switching device 1 comprises a housing 2 and a valve body part 3 arranged in the housing. The valve body part includes a fixed disc 13, a rotating disc 14 laminated on the fixed disc, and a rotating shaft 15. The housing, fixed disc and rotating disc have a plurality of communication passages 20, 30, 40 and 50, and a fluid flow passage is formed by the connection of the communication passages accompanied by the rotation of the rotating disc. Seal members 17, 18 for suppressing the leakage of fluid are arranged between at least the fixed disc and the rotating disc. A tip part 15a of the rotating shaft is arranged so as to be capable of abutting on and engaged with the fixed disc, and the fixed disc becomes reciprocal in an axial direction by the abutment and engagement of the tip part of the rotating shaft accompanied by the rotation.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a flow path switching device that switches a flow path of a fluid in a fluid circuit. [Background technology]

[0002] Conventionally, as a technique of this type, for example, a flow path switching device described in Patent Document 1 below is known. As described in paragraphs

[0156] to

[0166] and FIG. 10 of Patent Document 1, this device includes a housing 71 and a valve body portion 73 arranged inside the housing 71. The valve body portion 73 includes a fixed disc 75 and a drive disc 74 that is driven to rotate. The fixed disc 75 is arranged so as to divide the interior of the housing 71, and has a plurality of communication passages 75a, 75b. The drive disc 74 is formed in a plate shape of a size that can close the communication passages 75a, 75b. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-21966 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in the device described in Patent Document 1, it is conceivable to provide sealing members around the communicating passages 75a and 75b between the fixed disk 75 and the driving disk 74. In this case, when the driving disk 74 is driven to rotate to switch between the communicating passages 75a and 75b, the edges of the communicating passages 75a and 75b or the edges of the driving disk 74 cross the sealing members with high surface pressure, which may cause sliding wear on the sealing members or cause the sealing members to become caught and come off.

[0005] This disclosed technology has been made in consideration of the above circumstances, and its purpose is to prevent the sealing member from coming off due to sliding wear or getting caught when the driving disk rotates in a flow path switching device in which a sealing member is provided at least between a fixed disk and a driving disk. [Means for solving the problem]

[0006] In order to achieve the above object, the technology described in claim 1 is a flow path switching device comprising a housing and a valve body portion arranged inside the housing, the valve body portion including a fixed disk, a drive disk stacked on the fixed disk and rotating relative to the fixed disk, and a rotating shaft for rotating the drive disk, the housing, fixed disk and drive disk each having a plurality of communicating passages which are configured to be connected as the drive disk rotates to form a fluid flow path, and a sealing member provided in the flow path to suppress fluid leakage at least between the fixed disk and the drive disk, wherein the tip of the rotating shaft is configured to be able to abut and engage with the fixed disk, and the fixed disk is configured to be able to move back and forth in the axial direction as the tip of the rotating shaft abuts and engages with it as it rotates.

[0007] In the configuration of the above technology, the drive disk rotates relative to the fixed disk as the rotating shaft rotates. At this time, the seal member between at least the fixed disk and the drive disk reduces sliding resistance associated with the rotation of the drive disk. That is, according to the above configuration, the tip of the rotating shaft is provided so as to be able to abut and engage with the fixed disk, and the fixed disk is configured to be able to move back and forth in the axial direction as the tip of the rotating shaft abuts and engages with it as it rotates. Therefore, when the drive disk rotates in accordance with the rotation of the rotating shaft, the fixed disk moves back and forth in the axial direction, widening the gap between the housing and the drive disk and the gap between the fixed disk and the drive disk. This reduces the surface pressure applied to the seal members between the housing and the drive disk and between the fixed disk and the drive disk, thereby reducing the sliding resistance of each seal member 17, 18.

[0008] In order to achieve the above object, the technology described in claim 2 is the technology described in claim 1, wherein the tip of the rotating shaft includes shaft convex portions and shaft concave portions aligned in the circumferential direction, the fixed disk includes disk concave portions and disk convex portions that can abut and engage with the shaft convex portions and shaft concave portions, and the shaft convex portions and shaft concave portions as well as the disk concave portions and disk convex portions include side portions that are inclined in the circumferential direction.

[0009] According to the configuration of the above technology, in addition to the function of the technology described in claim 1, by rotating the rotating shaft, a state in which the shaft convex portion and the disk convex portion abut (convex-convex abutment state) and a state in which the shaft convex portion and shaft concave portion engage with the disk concave portion and disk convex portion (convex-concave engagement state) are obtained. Here, in the convex-convex abutment state, the fixed disk moves axially, widening the gap between the housing and the drive disk and the gap between the fixed disk and the drive disk, thereby reducing the surface pressure applied to the seal members between the housing and the drive disk and between the fixed disk and the drive disk. In contrast, in the convex-concave engagement state, the fixed disk moves axially, returning the gap between the housing and the drive disk and between the fixed disk and the drive disk to their original gaps, thereby restoring the surface pressure applied to the seal members between the housing and the drive disk and between the fixed disk and the drive disk to their original state. Switching between the convex-convex abutment state and the convex-concave engagement state is achieved via a state in which the inclined side surfaces of the shaft convex portion and the shaft concave portion come into contact with the disk concave portion and the disk convex portion.

[0010] In order to achieve the above object, the technology described in claim 3 is the technology described in claim 2, in which the top of at least one of the shaft convex portion and the disk convex portion is formed into a flat surface or a convex curved surface, and the bottom of at least one of the disk concave portion and the shaft concave portion is formed into a flat surface or a concave curved surface.

[0011] According to the configuration of the above technology, in addition to the effect of the technology described in claim 2, when the shaft protrusion and the disk protrusion are in contact with each other, the top of at least one of the shaft protrusion and the disk protrusion is formed into a flat surface or a convex curved surface, so that when the rotating shaft is rotated from this state, the axial position of the rotating shaft does not change suddenly. Also, since the bottom of at least one of the disk recess and the shaft recess is formed into a flat surface or a concave curved surface, the axial position of the rotating shaft does not change suddenly when the rotating shaft is rotated with the shaft protrusion and shaft recess engaged with the disk recess and disk protrusion.

[0012] In order to achieve the above object, the technology described in claim 4 is the technology described in claim 2, wherein the disk recess has a V-shaped gently sloping concave surface at its bottom and a steeply sloping surface that continues from the gently sloping concave surface to the disk protrusion and forms the side surface of the disk protrusion, the shaft protrusion has a V-shaped gently sloping convex surface at its top that matches the gently sloping concave surface, and the side surface of the shaft protrusion that continues from the gently sloping convex surface has a steeply sloping surface that matches the steeply sloping surface of the side surface of the disk protrusion.

[0013] According to the configuration of the above technology, in addition to the effect of the technology described in claim 2, when the shaft protrusion of the rotating shaft engages with the disk recess of the fixed disk and the convex, gently inclined surface of the shaft protrusion comes into contact with the concave, gently inclined surface of the disk recess, and when the rotating shaft starts to rotate, the shaft protrusion starts to slide against the disk recess at a gentle slope, and the sliding occurs due to the contact surface between the convex, gently inclined surface and the concave, gently inclined surface. Furthermore, as the rotation of the rotating shaft progresses, the contact surface between the disk recess and the shaft protrusion transitions from the contact surface between the concave, gently inclined surface and the convex, gently inclined surface to the contact surface between the steeply inclined surfaces, and the sliding occurs due to the contact surface.

[0014] In order to achieve the above object, the technology described in claim 5 is a technology described in any one of claims 1 to 4, in which the drive disk and the rotating shaft are connected so as to be able to move relative to each other in the rotational direction and the axial direction.

[0015] According to the configuration of the above technology, in addition to the effect of the technology described in any one of claims 1 to 4, the drive disk and the rotating shaft are connected to be relatively movable in the rotational and axial directions. Therefore, when the drive disk rotates and a surface pressure is applied to the seal member, the drive disk moves in the rotational and axial directions within the gap between the housing and the fixed disk, and is positioned in a position that is balanced with the reaction force of the seal member.

[0016] In order to achieve the above object, the technology described in claim 6 is the technology described in claim 5, wherein the connection portion between the rotating shaft and the drive disk has a gap in the rotation direction.

[0017] According to the configuration of the above technology, in addition to the effect of the technology described in claim 5, the connection part between the rotating shaft and the drive disk has a gap in the rotation direction, so when the rotating shaft is rotated, the rotating shaft rotates freely by the amount of the gap in the connection part.

[0018] In order to achieve the above object, the technology described in claim 7 is the technology described in claim 6, in which the idling angle at which the rotating shaft idles through the gap when the tip of the rotating shaft moves from a state in which it engages with the fixed disk to a state in which it abuts, and the switching angle at which the drive disk rotates to switch the flow path are set to the same angle.

[0019] According to the configuration of the above technology, in addition to the effect of the technology described in claim 6, when the tip of the rotating shaft moves from a state in which it engages with the fixed disk to a state in which it abuts, that is, when the fixed disk moves axially to widen the gap between the housing and the drive disk and the gap between the fixed disk and the drive disk, the idling angle of the rotating shaft and the switching angle of the drive disk when switching the flow path are set to the same angle. Therefore, by rotating the rotating shaft in the opposite direction by the switching angle and the idling angle, it is possible to return the rotational positions of the rotating shaft and the drive disk to their original states.

[0020] In order to achieve the above object, the technology described in claim 8 is the technology described in claim 7, further comprising a driving means for driving the rotating shaft to rotate, and a control means for controlling the driving means, and the control means controls the driving means to rotate the rotating shaft and switch the flow path with the tip of the rotating shaft abutting against the fixed disk, and then rotate the rotating shaft in the opposite direction, and stop the rotation of the rotating shaft with the tip of the rotating shaft engaged with the fixed disk.

[0021] According to the configuration of the above technology, in addition to the effect of the technology described in claim 7, the control means controls the drive means to rotate the rotating shaft, switch the flow path in a state where the tip of the rotating shaft abuts against the fixed disk (a state where the gap between the housing and the drive disk and the gap between the fixed disk and the drive disk are widened), and then rotate the rotating shaft in the opposite direction, and stop the rotation of the rotating shaft in a state where the tip of the rotating shaft engages with the fixed disk (a state where the gap between the housing and the drive disk and the gap between the fixed disk and the drive disk are returned to their original state). This makes it possible to reliably return the gap between the housing and the drive disk and the gap between the fixed disk and the drive disk to their original states after switching the flow path. [Effects of the Invention]

[0022] According to the technology described in claim 1, it is possible to prevent the seal member from coming off due to sliding wear or getting caught when the drive disk rotates.

[0023] According to the technology recited in claim 2, in addition to the effect of the technology recited in claim 1, it is possible to smoothly switch between the convex-convex abutment state and the convex-concave engagement state.

[0024] According to the technology recited in claim 3, in addition to the effect of the technology recited in claim 2, sliding wear of the seal member can be further suppressed.

[0025] According to the technology described in claim 4, in addition to the effect of the technology described in claim 2, when the rotating shaft starts to rotate from a state in which the shaft convex portion is engaged with the disk concave portion, the driving torque required to rotate the rotating shaft can be reduced, and wear on the shaft convex portion and the disk concave portion can be suppressed.

[0026] According to the technology described in claim 5, in addition to the effect of the technology described in any one of claims 1 to 4, the surface pressure applied to the sealing member when the drive disk rotates can be further reduced, thereby improving the durability of the sealing member.

[0027] According to the technology described in claim 6, in addition to the effect of the technology described in claim 5, even if the rotating shaft is rotated, the drive disk does not rotate, and the gap between the housing and the drive disk and the gap between the fixed disk and the drive disk can be set to a widened state.

[0028] According to the technology described in claim 7, in addition to the effect of the technology described in claim 6, the flow path switching operation when the rotating shaft is rotated in one direction can be made to coincide with the flow path switching operation when the rotating shaft is rotated in the opposite direction.

[0029] According to the technology recited in claim 8, in addition to the effect of the technology recited in claim 7, it is possible to ensure the sealing performance of the sealing member. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 2 is a perspective view showing a flow path switching device according to the first embodiment. [Figure 2] FIG. 2 is a front view showing the flow path switching device in the first embodiment. [Figure 3] FIG. 2 is a plan view showing the flow path switching device according to the first embodiment. [Figure 4] FIG. 3 is a bottom view showing the flow path switching device in the first embodiment. [Figure 5] FIG. 2 is an exploded perspective view showing the flow path switching device according to the first embodiment. [Figure 6]4 is a cross-sectional view taken along line AA in FIG. 3 showing the flow path switching device according to the first embodiment. [Figure 7] FIG. 2 is a plan view showing a rotary disk in the first embodiment. [Figure 8] FIG. 2 is an exploded perspective view showing an upper housing and a rotary shaft in the first embodiment. [Figure 9] FIG. 2 is a perspective view showing a fixed disk in the first embodiment. [Figure 10] 10 is an enlarged view showing the engaged structure of the fixed disc shown in FIG. 9 in the first embodiment. [Figure 11] FIG. 3 is a front view showing a rotation shaft in the first embodiment. [Figure 12] 12 is a perspective view showing a part of the engagement structure surrounded by a dashed-dotted circle in FIG. 11 according to the first embodiment. FIG. [Figure 13] FIG. 3 is a cross-sectional view illustrating a simplified pre-operation state of the upper housing, the rotary disc, the fixed disc, the rotary shaft, and the like in the first embodiment. [Figure 14] FIG. 14 is a cross-sectional view taken along line BB in FIG. 13, showing the rotary disk and the rotary shaft according to the first embodiment. [Figure 15] FIG. 10 is a cross-sectional view illustrating a simplified operation start state of the upper housing, the rotary disc, the fixed disc, the rotary shaft, etc., in which only the rotary shaft has rotated, in the first embodiment. [Figure 16] 16 is a cross-sectional view taken along line CC in FIG. 15, showing the rotary disk and the rotary shaft according to the first embodiment. [Figure 17] FIG. 3 is a cross-sectional view illustrating the first embodiment, in a simplified manner, an operating state of the upper housing, the rotary disk, the fixed disk, the rotary shaft, and the like when the rotary disk rotates. [Figure 18] FIG. 18 is a cross-sectional view taken along line DD in FIG. 17, showing the rotary disk and the rotary shaft according to the first embodiment. [Figure 19] FIG. 10 is a cross-sectional view illustrating an outline of the upper housing, the rotary disk, the fixed disk, the rotary shaft, etc. in the final state after the rotary shaft and the rotary disk have further rotated in the first embodiment. [Figure 20] FIG. 20 is a cross-sectional view taken along line EE in FIG. 19, showing the rotary disk and the rotary shaft according to the first embodiment. [Figure 21]FIG. 10 is a plan view showing a state in which an upper housing and a drive unit are removed from the flow path switching device according to a second embodiment. [Figure 22] 22 is an enlarged plan view of the through-hole and the rotary shaft (enclosed by the dashed line) in FIG. 21 according to the second embodiment. FIG. [Figure 23] FIG. 10 is a perspective view showing a rotation shaft according to a second embodiment. [Figure 24] 24 is an enlarged perspective view of the engagement structure at the tip of the rotary shaft shown in FIG. 23 according to the second embodiment. FIG. [Figure 25] FIG. 10 is a plan view showing a fixed disk in the second embodiment. [Figure 26] FIG. 26 is an enlarged perspective view of the engaged structure of the fixed disk shown in FIG. 25 according to the second embodiment. [Figure 27] 21A and 21B show the "initial state" of the flow path switching device according to the second embodiment, in which (A) is an image diagram showing the engagement relationship between the through hole of the rotating disk and the rotating shaft, (B) is an image diagram showing the change in lift of the rotating shaft relative to the angle of the rotating shaft, (C) is a plan view showing the rotational position of the through hole and the rotating shaft, and the positional relationship between the disk convex portion, the disk concave portion and the shaft convex portion, and (D) is a plan view similar to FIG. 21 showing the rotational position of the rotating disk and the rotary connecting passage. [Figure 28] 27(A) is an image diagram equivalent to FIG. 27(A), FIG. 27(B) is an image diagram equivalent to FIG. 27(B), FIG. 27(C) is a plan view equivalent to FIG. 27(C), and FIG. 27(D) is a plan view equivalent to FIG. 27(D). [Figure 29] 27(A) is an image diagram similar to FIG. 27(A), FIG. 27(B) is an image diagram similar to FIG. 27(B), FIG. 27(C) is a plan view similar to FIG. 27(C), and FIG. 27(D) is a plan view similar to FIG. 27(D). [Figure 30] 27(A) is an image diagram equivalent to FIG. 27(A), FIG. 27(B) is an image diagram equivalent to FIG. 27(B), FIG. 27(C) is a plan view equivalent to FIG. 27(C), and FIG. 27(D) is a plan view equivalent to FIG. 27(D) according to the second embodiment. [Figure 31] 27(A) is an image diagram equivalent to FIG. 27(A), FIG. 27(B) is an image diagram equivalent to FIG. 27(B), FIG. 27(C) is a plan view equivalent to FIG. 27(C), and FIG. 27(D) is a plan view equivalent to FIG. 27(D). [Figure 32] 27(A) is an image diagram equivalent to FIG. 27(A), FIG. 27(B) is an image diagram equivalent to FIG. 27(B), FIG. 27(C) is a plan view equivalent to FIG. 27(C), and FIG. 27(D) is a plan view equivalent to FIG. 27(D) in the second embodiment. [Figure 33] 27(A) is an image diagram equivalent to FIG. 27(A), FIG. 27(B) is an image diagram equivalent to FIG. 27(B), FIG. 27(C) is a plan view equivalent to FIG. 27(C), and FIG. 27(D) is a plan view equivalent to FIG. 27(D) according to the second embodiment. [Figure 34] 27(A) is an image diagram equivalent to FIG. 27(A), FIG. 27(B) is an image diagram equivalent to FIG. 27(B), FIG. 27(C) is a plan view equivalent to FIG. 27(C), and FIG. 27(D) is a plan view equivalent to FIG. 27(D). [Figure 35] 27(A) is an image diagram equivalent to FIG. 27(A), FIG. 27(B) is an image diagram equivalent to FIG. 27(B), FIG. 27(C) is a plan view equivalent to FIG. 27(C), and FIG. 27(D) is a plan view equivalent to FIG. 27(D). [Figure 36] 27(A) is an image diagram equivalent to FIG. 27(A), FIG. 27(B) is an image diagram equivalent to FIG. 27(B), FIG. 27(C) is a plan view equivalent to FIG. 27(C), and FIG. 27(D) is a plan view equivalent to FIG. 27(D). [Figure 37]27(A) is an image diagram similar to FIG. 27(A), FIG. 27(B) is an image diagram similar to FIG. 27(B), FIG. 27(C) is a plan view similar to FIG. 27(C), and FIG. 27(D) is a plan view similar to FIG. 27(D) according to the second embodiment. [Figure 38] 27(A) is an image diagram equivalent to FIG. 27(A), FIG. 27(B) is an image diagram equivalent to FIG. 27(B), FIG. 27(C) is a plan view equivalent to FIG. 27(C), and FIG. 27(D) is a plan view equivalent to FIG. 27(D). [Figure 39] 27(A) is an image diagram similar to FIG. 27(A), FIG. 27(B) is an image diagram similar to FIG. 27(B), FIG. 27(C) is a plan view similar to FIG. 27(C), and FIG. 27(D) is a plan view similar to FIG. 27(D), showing the "return initial state" of the flow path switching device according to the second embodiment. [Figure 40] 27(A) is an image diagram equivalent to FIG. 27(A), FIG. 27(B) is an image diagram equivalent to FIG. 27(B), and FIG. 27(C) is a plan view equivalent to FIG. 27(D) showing the "initial state" of the flow path switching device according to the third embodiment. [Figure 41] 40(B) and 40(C) are plan views showing the "45° rotated state" of the flow path switching device according to the third embodiment, where (A) is an image diagram similar to FIG. 40(A), (B) is an image diagram similar to FIG. 40(B), and (C) is a plan view similar to FIG. 40(C). [Figure 42] This figure relates to the third embodiment and shows the "90° rotated state" of the flow path switching device, where (A) is an image diagram similar to Figure 41(A), (B) is an image diagram similar to Figure 41(B), and (C) is a plan view similar to Figure 41(C). [Figure 43] 41(B) and 41(C) are plan views showing the flow path switching device in the "45° rotation back state" according to the third embodiment, where (A) is an image diagram similar to FIG. 41(A), (B) is an image diagram similar to FIG. 41(B), and (C) is a plan view similar to FIG. 41(C). [Figure 44]This figure relates to the third embodiment and shows the "return initial state" of the flow path switching device, where (A) is an image diagram similar to Figure 41(A), (B) is an image diagram similar to Figure 41(B), and (C) is a plan view similar to Figure 41(C). [Figure 45] 40(A) is an image diagram similar to FIG. 40(A), FIG. 40(B) is an image diagram similar to FIG. 40(B), and FIG. 40(C) is a plan view similar to FIG. 40(D), showing the "initial state" of the flow path switching device according to the fourth embodiment. [Figure 46] 45(A) is an image diagram equivalent to FIG. 45(A), FIG. 45(B) is an image diagram equivalent to FIG. 45(B), and FIG. 45(C) is a plan view equivalent to FIG. 45(C) showing the "22.5° rotation state" of the flow path switching device according to the fourth embodiment. [Figure 47] 45(A) is an image diagram equivalent to FIG. 45(A), FIG. 45(B) is an image diagram equivalent to FIG. 45(B), and FIG. 45(C) is a plan view equivalent to FIG. 45(C) showing the "67.5° rotation state" of the flow path switching device according to the fourth embodiment. [Figure 48] 45(B) and 45(C) show the flow path switching device in the "45° rotated back state" according to the fourth embodiment, where (A) is an image diagram similar to FIG. 45(A), (B) is an image diagram similar to FIG. 45(B), and (C) is a plan view similar to FIG. 45(C). [Figure 49] 45(A) is an image diagram similar to FIG. 45(A), FIG. 45(B) is an image diagram similar to FIG. 45(B), and FIG. 45(C) is a plan view similar to FIG. 45(C) showing the "return initial state" of the flow path switching device according to the fourth embodiment. [Figure 50] 40(A) is an image diagram similar to FIG. 40(A), FIG. 40(B) is an image diagram similar to FIG. 40(B), and FIG. 40(C) is a plan view similar to FIG. 40(D), showing the "initial state" of the flow path switching device according to the fifth embodiment. [Figure 51] 5A and 5B show the "45° rotated state" of the flow path switching device according to the fifth embodiment, where (A) is an image diagram similar to FIG. 50A, (B) is an image diagram similar to FIG. 50B, and (C) is a plan view similar to FIG. 50C. [Figure 52]50(A) and 50(B) are schematic diagrams showing the "90° rotated state" of the flow path switching device according to the fifth embodiment, where (A) is an image diagram similar to FIG. 50(A), (B) is an image diagram similar to FIG. 50(B), and (C) is a plan view similar to FIG. 50(C). [Figure 53] 5A and 5B show the "135° rotation state" of the flow path switching device according to the fifth embodiment, where (A) is an image diagram similar to FIG. 50A, (B) is an image diagram similar to FIG. 50B, and (C) is a plan view similar to FIG. 50C. [Figure 54] 50(B) and 50(C) show the flow path switching device in the "90° rotated back state" according to the fifth embodiment, where (A) is an image diagram similar to FIG. 50(A), (B) is an image diagram similar to FIG. 50(B), and (C) is a plan view similar to FIG. 50(C). [Figure 55] 5A and 5B show the flow path switching device in the "45° rotated back state" according to the fifth embodiment, where (A) is an image diagram similar to FIG. 50A, (B) is an image diagram similar to FIG. 50B, and (C) is a plan view similar to FIG. 50C. [Figure 56] 50(A) and 50(B) are diagrams showing the "re-90° rotation state" of the flow path switching device according to the fifth embodiment, where (A) is an image diagram similar to FIG. 50(A), (B) is an image diagram similar to FIG. 50(B), and (C) is a plan view similar to FIG. 50(C). [Figure 57] 5A and 5B show the flow path switching device in the "45° rotated back state" according to the fifth embodiment, where (A) is an image diagram similar to FIG. 50A, (B) is an image diagram similar to FIG. 50B, and (C) is a plan view similar to FIG. 50C. [Figure 58] 50(A) is an image diagram similar to FIG. 50(A), FIG. 50(B) is an image diagram similar to FIG. 50(B), and FIG. 50(C) is a plan view similar to FIG. 50(C) showing the "return initial state" of the flow path switching device according to the fifth embodiment. [Figure 59] FIG. 13 is a perspective view showing the upper surface side of the flow path switching device according to the sixth embodiment. [Figure 60] FIG. 13 is a perspective view showing the bottom side of the flow path switching device according to the sixth embodiment. [Figure 61] FIG. 13 is a plan view showing a flow path switching device according to a sixth embodiment. [Figure 62] FIG. 13 is a plan view showing a state in which an upper housing and a drive unit are removed from the flow path switching device according to a sixth embodiment. [Figure 63] FIG. 63 is an enlarged plan view showing the through-hole and the rotary shaft in FIG. 62 according to the sixth embodiment. [Figure 64] FIG. 13 is a perspective view showing a rotation shaft according to a sixth embodiment. [Figure 65] FIG. 65 is an enlarged perspective view of the engagement structure at the tip of the rotating shaft shown in FIG. 64 according to the sixth embodiment. [Figure 66] FIG. 13 is a plan view showing a fixed disk in the sixth embodiment. [Figure 67] FIG. 67 is an enlarged perspective view of the engaged structure of the fixed disk shown in FIG. 66 according to the sixth embodiment. [Figure 68] 27(A) is an image diagram similar to FIG. 27(A), FIG. 27(B) is an image diagram similar to FIG. 27(B), FIG. 27(C) is a plan view similar to FIG. 27(C), and FIG. 27(D) is a plan view similar to FIG. 27(D). [Figure 69] This figure relates to the sixth embodiment and shows the "30° rotation state" of the flow path switching device, where (A) is an image diagram similar to Figure 68(A), (B) is an image diagram similar to Figure 68(B), (C) is a plan view similar to Figure 68(C), and (D) is a plan view similar to Figure 68(D). [Figure 70] This figure relates to the sixth embodiment and shows the "60° rotated state" of the flow path switching device, where (A) is an image diagram similar to Figure 68(A), (B) is an image diagram similar to Figure 68(B), (C) is a plan view similar to Figure 68(C), and (D) is a plan view similar to Figure 68(D). [Figure 71] This figure relates to the sixth embodiment and shows the "30° rotated back state" of the flow path switching device, where (A) is an image diagram similar to Figure 68(A), (B) is an image diagram similar to Figure 68(B), (C) is a plan view similar to Figure 68(C), and (D) is a plan view similar to Figure 68(D). [Figure 72]This figure relates to the sixth embodiment and shows the "return 0° rotation state" of the flow path switching device, where (A) is an image diagram similar to Figure 68(A), (B) is an image diagram similar to Figure 68(B), (C) is a plan view similar to Figure 68(C), and (D) is a plan view similar to Figure 68(D). [Figure 73] This figure relates to the sixth embodiment and shows the "30° re-rotation state" of the flow path switching device, where (A) is an image diagram similar to Figure 68(A), (B) is an image diagram similar to Figure 68(B), (C) is a plan view similar to Figure 68(C), and (D) is a plan view similar to Figure 68(D). [Figure 74] This figure relates to the sixth embodiment and shows the "re-rotated 60° state" of the flow path switching device, where (A) is an image diagram similar to Figure 68(A), (B) is an image diagram similar to Figure 68(B), (C) is a plan view similar to Figure 68(C), and (D) is a plan view similar to Figure 68(D). [Figure 75] This figure relates to the sixth embodiment and shows the "90° rotated state" of the flow path switching device, where (A) is an image diagram similar to Figure 68(A), (B) is an image diagram similar to Figure 68(B), (C) is a plan view similar to Figure 68(C), and (D) is a plan view similar to Figure 68(D). [Figure 76] This figure relates to the sixth embodiment and shows the "60° return rotation state" of the flow path switching device, where (A) is an image diagram similar to Figure 68(A), (B) is an image diagram similar to Figure 68(B), (C) is a plan view similar to Figure 68(C), and (D) is a plan view similar to Figure 68(D). [Figure 77] This figure relates to the sixth embodiment and shows the "30° rotated back state" of the flow path switching device, where (A) is an image diagram similar to Figure 68(A), (B) is an image diagram similar to Figure 68(B), (C) is a plan view similar to Figure 68(C), and (D) is a plan view similar to Figure 68(D). [Figure 78] This figure relates to the sixth embodiment and shows the "return 0° rotation state" of the flow path switching device, where (A) is an image diagram similar to Figure 68(A), (B) is an image diagram similar to Figure 68(B), (C) is a plan view similar to Figure 68(C), and (D) is a plan view similar to Figure 68(D). [Figure 79] This figure relates to the sixth embodiment and shows the "-30° rotation state" of the flow path switching device, where (A) is an image diagram similar to Figure 68(A), (B) is an image diagram similar to Figure 68(B), (C) is a plan view similar to Figure 68(C), and (D) is a plan view similar to Figure 68(D). [Figure 80] This figure relates to the sixth embodiment and shows the "return initial state" of the flow path switching device, where (A) is an image diagram similar to Figure 68(A), (B) is an image diagram similar to Figure 68(B), (C) is a plan view similar to Figure 68(C), and (D) is a plan view similar to Figure 68(D). [Figure 81] 13 is a flowchart showing an example of the contents of flow path switching control according to the sixth embodiment. [Figure 82] 13 is a flowchart showing an example of the contents of flow path switching control according to the sixth embodiment. [Figure 83] 13 is a flowchart showing an example of the contents of flow path switching control according to the sixth embodiment. [Figure 84] This figure relates to the seventh embodiment and shows the "initial state" of the flow path switching device, where (A) is an image diagram similar to Figure 68(A), (B) is an image diagram similar to Figure 68(B), and (C) is a plan view similar to Figure 68(D). [Figure 85] This figure relates to the seventh embodiment and shows the "30° rotated state" of the flow path switching device, where (A) is an image diagram similar to Figure 84(A), (B) is an image diagram similar to Figure 84(B), and (C) is a plan view similar to Figure 84(C). [Figure 86] This figure relates to the seventh embodiment and shows the "60° rotated state" of the flow path switching device, where (A) is an image diagram similar to Figure 84(A), (B) is an image diagram similar to Figure 84(B), and (C) is a plan view similar to Figure 84(C). [Figure 87] 84(A) and 84(B) are schematic diagrams showing the flow path switching device in the "30° rotated back state" according to the seventh embodiment, where (A) is an image diagram similar to FIG. 84(A), (B) is an image diagram similar to FIG. 84(B), and (C) is a plan view similar to FIG. 84(C). [Figure 88]84(B) and 84(C) show the flow path switching device in the "return 0° rotation state" according to the seventh embodiment, where (A) is an image diagram similar to FIG. 84(A), (B) is an image diagram similar to FIG. 84(B), and (C) is a plan view similar to FIG. 84(C). [Figure 89] This figure relates to the seventh embodiment and shows the "-30° rotation state" of the flow path switching device, where (A) is an image diagram similar to Figure 84(A), (B) is an image diagram similar to Figure 84(B), and (C) is a plan view similar to Figure 84(C). [Figure 90] 84(A) and 84(B) are schematic diagrams showing the "return initial state" of the flow path switching device according to the seventh embodiment, where (A) is an image diagram similar to FIG. 84(A), (B) is an image diagram similar to FIG. 84(B), and (C) is a plan view similar to FIG. 84(C). [Figure 91] 40(B) is an image diagram showing the relationship between the engaging structure and the engaged structure; and FIG. 40(C) is an image diagram similar to FIG. 40(B), showing the "initial state" of the flow path switching device according to the eighth embodiment. [Figure 92] 91(A) is an image diagram similar to FIG. 91(A), (B) is an image diagram similar to FIG. 91(B), and (C) is an image diagram similar to FIG. 91(C) relating to the eighth embodiment, showing the "45° rotated state" of the flow path switching device. [Figure 93] 91(A) is an image diagram similar to FIG. 91(A), (B) is an image diagram similar to FIG. 91(B), and (C) is an image diagram similar to FIG. 91(C) relating to the eighth embodiment, showing the "90° rotated state" of the flow path switching device. [Figure 94] 91(A) is an image diagram similar to FIG. 91(A), (B) is an image diagram similar to FIG. 91(B), and (C) is an image diagram similar to FIG. 91(C) showing the "45° return rotation state" of the flow path switching device according to the eighth embodiment. [Figure 95] 91(A) is an image diagram similar to FIG. 91(A), (B) is an image diagram similar to FIG. 91(B), and (C) is an image diagram similar to FIG. 91(C) relating to the eighth embodiment, showing the "return initial state" of the flow path switching device. [Figure 96] FIG. 13 is an image diagram illustrating the relationship between the engaging structure and the engaged structure when the rotating shaft is lifted down before switching the flow path according to the ninth embodiment. [Figure 97] FIG. 13 is an image diagram illustrating the relationship between the engaging structure and the engaged structure when the rotating shaft is lifted up during flow path switching in the ninth embodiment. [Figure 98] FIG. 13 is an image diagram illustrating the relationship between the engaging structure and the engaged structure when the rotating shaft is lifted up during flow path switching according to the ninth embodiment. [Figure 99] FIG. 13 is a conceptual diagram relating to a comparative example (eighth embodiment) and showing the relationship between the engaging structure and the engaged structure when the rotating shaft is lifted down before switching the flow path. [Figure 100] FIG. 13 is a conceptual diagram relating to a comparative example (eighth embodiment) and showing the relationship between the engaging structure and the engaged structure when the rotating shaft is being lifted up during flow path switching. [Figure 101] FIG. 13 is a conceptual diagram relating to a comparative example (eighth embodiment) and showing the relationship between the engaging structure and the engaged structure when the rotating shaft is lifted up during flow path switching. [Figure 102] 13 is a graph showing the relationship between the change in the rotation angle of the rotary shaft and the change in the drive torque in the ninth embodiment. [Figure 103] FIG. 23 is an image diagram illustrating the relationship between the engaging structure and the engaged structure in a lift-down state before switching of the flow path according to the tenth embodiment. [Figure 104] FIG. 104 is an enlarged conceptual diagram showing the ground contact portion of FIG. 103 according to the tenth embodiment. [Figure 105] FIG. 23 is an image diagram showing the relationship between the engaging structure and the engaged structure at the start of flow path switching (at the initial drive when lift-up begins) in the tenth embodiment. [Figure 106] FIG. 23 is an image diagram showing the relationship between the engaging structure and the engaged structure during flow path switching (during lift-up) in the tenth embodiment. [Figure 107] FIG. 23 is an image diagram showing the relationship between the engaging structure and the engaged structure during flow path switching (during lift-up) in the tenth embodiment. [Figure 108]FIG. 108 is an enlarged conceptual diagram showing the ground contact portion in FIG. 107 according to the tenth embodiment. [Figure 109] 13 is an image diagram showing the relationship between the engaging structure and the engaged structure immediately after the top of the shaft protrusion has climbed over the top of the disk protrusion (starting to lift down) during flow path switching in the tenth embodiment. FIG. [Figure 110] FIG. 109 is an enlarged image diagram showing the ground contact portion of FIG. 109 according to the tenth embodiment. [Figure 111] FIG. 23 is an image diagram showing the relationship between the engaging structure and the engaged structure during flow path switching (during lift-down) in the tenth embodiment. [Figure 112] FIG. 23 is an image diagram showing the relationship between the engaging structure and the engaged structure before the flow path switching is completed (before the lift-down is completed) in the tenth embodiment. [Figure 113] FIG. 23 is an image diagram showing the relationship between the engaging structure and the engaged structure when flow path switching is completed (when lift-down is completed) in the tenth embodiment. [Figure 114] FIG. 108 is an image diagram similar to FIG. 107 showing the relationship between the engaging structure and the engaged structure during flow path switching (during lift-up) in the eleventh embodiment. [Figure 115] FIG. 115 is an enlarged conceptual diagram showing the ground contact portion in FIG. 114 according to the eleventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, several embodiments of the flow path switching device will be described in detail with reference to the drawings.

[0032] First Embodiment First, the first embodiment will be described in detail with reference to FIGS.

[0033] [Outline of flow path switching device] FIG. 1 shows a perspective view of the flow path switching device 1 of this embodiment. FIG. 2 shows a front view of the flow path switching device 1. FIG. 3 shows a plan view of the flow path switching device 1. FIG. 4 shows a bottom view of the flow path switching device 1. FIG. 5 shows an exploded perspective view of the flow path switching device 1. FIG. 6 shows a cross-sectional view of the flow path switching device 1 taken along line AA in FIG. 3. As shown in FIGS. 1 to 6, the flow path switching device 1 includes a housing 2, a valve body portion 3 arranged inside the housing 2, and a drive portion 4 that drives the valve body portion 3.

[0034] [About housing] The housing 2 is formed by fastening an upper housing 11 and a lower housing 12 with a plurality of screws 6. The housing 2 includes an inflow channel 20 through which a fluid flows in and an outflow channel 30 through which the fluid flows out. Here, the flow channel switching device 1 is configured as an eight-way valve, for example, and the housing 2 has four inflow channels 20 and four outflow channels 30. As the four inflow channels 20, the upper housing 11 is provided with a first inflow channel 21, a second inflow channel 22, a third inflow channel 23, and a fourth inflow channel 24. Furthermore, as the four outflow channels 30, the lower housing 12 is provided with a first outflow channel 31, a second outflow channel 32, a third outflow channel 33, and a fourth outflow channel 34. The inflow channels 20 and the outflow channels 30 correspond to an example of a "communication channel" provided in a "housing" of the disclosed technology. In this embodiment, the housing 2 is formed, for example, from resin.

[0035] [About the valve body] As shown in Figures 5 and 6, the valve body portion 3 includes a fixed disk 13 that does not rotate in the housing 2, a rotating disk 14 that is stacked on the fixed disk 13 and rotates relative to the fixed disk 13, and a rotating shaft 15 for rotating the rotating disk 14. The rotating disk 14 and the fixed disk 13 are stacked in the axial direction X. The rotating disk 14 corresponds to an example of a "drive disk" in the technology disclosed herein. The rotating disk 14 and the fixed disk 13 are formed, for example, from resin.

[0036] [About the rotating disc] FIG. 7 shows a plan view of the rotating disk 14. As shown in FIGS. 6 and 7, the rotating disk 14 is accommodated inside the housing 2. The rotating disk 14 is formed in a thick, circular disk shape and includes four rotation communication passages 40 that penetrate in the axial direction X. The four rotation communication passages 40 include a first rotation communication passage 41, a second rotation communication passage 42, a third rotation communication passage 43, and a fourth rotation communication passage 44. These rotation communication passages 40 are formed in the shape of slightly curved elongated holes in a plan view. These rotation communication passages 40 correspond to an example of a "communication passage" provided in a "drive disk" of the technology disclosed herein. A through hole 14a, through which the rotating shaft 15 penetrates, is formed in the center of the rotating disk 14. This through hole 14a has a cross-sectional shape (oval shape) that is larger than the outer diameter of the rotating shaft 15.

[0037] [About the rotation axis] FIG. 8 shows an exploded perspective view of the upper housing 11 and the rotating shaft 15. In this embodiment, the rotating shaft 15 is made of resin. The rotating shaft 15 is provided to penetrate the upper housing 11 and the rotating disk 14, and is connected to the fixed disk 13 and the rotating disk 14 at one end in the axial direction X (the lower end side in FIGS. 5 and 6 ), and is connected to the driving unit 4 at the other end in the axial direction X (the upper end side in FIGS. 5 and 6 ). As shown in FIG. 8 , the other end of the rotating shaft 15 extends upward through a through-hole 11a formed in the upper housing 11 and is connected to the driving unit 4. As shown in FIG. 6 , a lip seal 26 is provided between the upper housing 11 and the rotating shaft 15. The rotating shaft 15 may be made of metal.

[0038] In this embodiment, the rotating disk 14 and the rotating shaft 15 are connected to each other so as to be relatively movable in the rotational direction and the axial direction. That is, as shown in FIGS. 5 to 8, one end side of the rotating shaft 15 (the lower end side in FIGS. 5 and 6) has a cross-sectional shape (oval) similar to the through-hole 14a of the rotating disk 14, but has a smaller cross-sectional shape than the through-hole 14a. That is, the connection portion between the rotating shaft 15 and the rotating disk 14 (the through-hole 14a and the corresponding lower portion of the rotating shaft 15) has a gap 28 in the rotational direction (see FIGS. 13 to 20 described later). The rotating shaft 15 is connected to the through-hole 14a so as to be relatively movable in the rotational direction and the axial direction. The rotating shaft 15 is assembled into the through-hole 14a of the rotating disk 14 so that its central axis coincides with the central axis of the rotating disk 14. When the rotating shaft 15 receives a driving force from the drive unit 4 and rotates, it rotates freely in the through hole 14a by the gap 28, and then engages with the inner wall of the through hole 14a to rotate integrally with the rotating disk 14.

[0039] [About fixed disks] FIG. 9 shows a perspective view of the fixed disk 13. As shown in FIG. 6, the fixed disk 13 is housed inside the lower housing 12. As shown in FIGS. 5, 6, and 9, the fixed disk 13 includes a disk portion 13a and a plurality of tubular portions 13b extending downward from the disk portion 13a. The disk portion 13a is formed in a disk shape and includes four fixed communication passages 50 that penetrate in the axial direction. As shown in FIGS. 5 and 8, the four fixed communication passages 50 include a first fixed communication passage 51, a second fixed communication passage 52, a third fixed communication passage 53, and a fourth fixed communication passage 54. The fixed communication passages 50 correspond to an example of a "communication passage" provided in a "fixed disk" of the technology disclosed herein.

[0040] The four cylindrical portions 13b of the fixed disk 13 are formed integrally with the circular plate portion 13a, and their interiors form fixed communicating passages 50. Each cylindrical portion 13b is arranged to communicate with one of the outflow passages 30. A spring 16 is provided between the fixed disk 13 and the lower housing 12 to urge the fixed disk 13 toward the rotating disk 14. The spring 16 is arranged in the center of the lower surface 13c of the fixed disk 13 so as to be surrounded by the multiple cylindrical portions 13b. In addition, a lip seal 36 is provided between each cylindrical portion 13b and the lower housing 12 to ensure the sealing of the fixed communicating passages 50.

[0041] [About the drive unit] The drive unit 4 includes a motor and a speed reducer (not shown) for applying a rotational driving force to the rotary shaft 15. The flow path switching device 1 rotates the rotary disk 14 via the rotary shaft 15 using the drive unit 4, and switches the fluid flow path among several patterns by changing the combination of communication between the four rotary communication paths 40, the four inflow paths 20, and the four fixed communication paths 50. Here, a description of switching the flow path patterns will be omitted.

[0042] [About sealing materials] In this embodiment, seal members 17 and 18 are provided in the flow paths to prevent leakage of fluid between the housing 2, the fixed disk 13, and the rotating disk 14. As shown in FIGS. 5 to 7, the seal members 17 and 18 are provided on the rotating disk 14. That is, the seal members 17 and 18 are provided on the upper and lower end faces 14b and 14c of the rotating disk 14 so as to protrude from the upper and lower end faces 14b and 14c and surround the peripheries of the openings of the rotation communicating passages 40. In FIG. 6, four upper seal members 17 are provided on the upper end face 14b of the rotating disk 14 corresponding to the four rotation communicating passages 40, and four lower seal members 18 are provided on the lower end face 14c of the rotating disk 14 corresponding to the four rotation communicating passages 40. Both the upper and lower seal members 17 and 18 are made of fluororesin (e.g., Teflon (registered trademark)). Alternatively, the upper and lower seal members 17 and 18 may be made of rubber to which a fluororesin is attached. The upper and lower seal members 17 and 18 may be made of rubber only.

[0043] In this embodiment, the seal members 17 and 18 protruding from the upper and lower end surfaces 14b and 14c of the rotating disk 14 contact the inner surface of the upper housing 11 and the upper surface 13d of the fixed disk 13. Therefore, when the rotating disk 14 rotates, a large sliding resistance occurs between the seal members 17 and 18 and the upper housing 11 and the fixed disk 13. The sliding resistance is particularly large when the rotating disk 14 begins to rotate. To overcome this sliding resistance, it is possible to increase the output of the drive unit 4. However, this would increase the size of the drive unit 4 and the manufacturing costs of the drive unit 4. Therefore, in this embodiment, to solve the above problem, the flow path switching device 1 is provided with a sliding resistance reduction structure that reduces the sliding resistance of the seal members 17 and 18.

[0044] [About the sliding resistance reduction structure] That is, in this embodiment, as shown in Figures 5, 6 and 8, the tip end portion 15a (lower end portion in the figures) of the rotating shaft 15 is provided so as to be able to abut and engage with the fixed disk 13. The tip end portion 15a is provided with an engagement structure K1 (see Figure 8) for the fixed disk 13. The fixed disk 13 is configured so as to be able to move back and forth in the axial direction X as the tip end portion 15a of the rotating shaft 15 abuts and engages with it as it rotates. An engaged structure K2 (see Figure 9) with which the engaging structure K1 of the rotating shaft 15 engages is provided in the center of the upper surface of the fixed disk 13. The sliding resistance reducing structure is made up of the engaging structure K1 and the engaged structure K2.

[0045] FIG. 10 shows an enlarged view of the engagement structure K2 of the fixed disk 13 shown in FIG. 9. FIG. 11 shows a front view of the rotating shaft 15. FIG. 12 shows a perspective view of the engagement structure K1 (tip end portion 15a) surrounded by a dashed-dotted circle in FIG. 11. As shown in FIGS. 11 and 12, the tip end surface (lower end surface) of the tip end portion 15a of the rotating shaft 15 has multiple (four in this embodiment) protrusions (shaft convex portions) 15b arranged circumferentially along the outer periphery and forming a downwardly protruding mountain shape. These shaft convex portions 15b are alternately arranged at equal angular intervals. Each shaft convex portion 15b has a shape that converges toward its apex. Between adjacent shaft convex portions 15b, multiple (four in this embodiment) shaft concave portions 15c are arranged at equal angular intervals. These multiple shaft convex portions 15b and shaft concave portions 15c form the engagement structure K1 of the rotating shaft 15.

[0046] Meanwhile, at the center of the upper surface 13d of the fixed disk 13, with which the tip end 15a of the rotating shaft 15 abuts and engages, a plurality of grooves (disk recesses) 13e are formed in a circular, radial pattern at equal angular intervals. The shaft protrusions 15b abut and engage with the grooves as the rotating shaft 15 rotates, as shown in Fig. 10. Disk protrusions 13g are arranged at equal angular intervals between adjacent disk recesses 13e. The plurality of disk recesses 13e and disk protrusions 13g are arranged in a recess 13f that is circular in plan view and formed at the center of the upper surface 13d of the fixed disk 13. The plurality of disk recesses 13e and disk protrusions 13g form the engaged structure K2 of the fixed disk 13.

[0047] [About the function and effect of the flow path switching device] According to the configuration of the flow path switching device 1 of this embodiment described above, the valve body portion 3 provided inside the housing 2 includes a vertically stacked fixed disk 13 and rotary disk 14, and a rotary shaft 15. As described above, the valve body portion 3 has a vertically stacked disk structure, which enables complex flow path switching with a small number of components. Furthermore, since the flow path can be switched simply by rotating the rotary disk 14 to change the position of the rotary communicating passage 40, there is no need to provide any additional components for switching the flow path. Therefore, various flow path switching can be easily performed while miniaturizing the flow path switching device 1.

[0048] According to the configuration of this embodiment, the shaft protrusions 15b at the tip 15a of the rotating shaft 15 engage with and disengage from the multiple disk recesses 13e of the fixed disk 13 as the rotating shaft 15 rotates. The fixed disk 13 is biased by the spring 16 in a direction approaching the tip 15a of the rotating shaft 15. As a result, when the shaft protrusions 15b move from a misaligned state to an aligned state with the disk recesses 13e, the shaft protrusions 15b engage with the disk recesses 13e, and the biasing force of the spring 16 pushes the fixed disk 13 upward in a direction approaching the rotating disk 14, causing the fixed disk 13 to come into contact with the lower seal member 18. Meanwhile, the shaft protrusions 15b disengage from the corresponding disk recesses 13e and ride on the disk protrusions 13g between the disk recesses 13e. This pushes the fixed disk 13 downward in a direction away from the rotating disk 14 against the biasing force of the spring 16, causing the fixed disk 13 to separate from the lower seal member 18.

[0049] Here, Figures 13 to 20 show in stages the operation of the sliding resistance reduction structure when the flow path switching device 1 transitions from one flow path switching state to another, and the operation of the rotating shaft 15, rotating disk 14, and fixed disk 13 when the rotating shaft 15 rotates and the rotating disk 14 rotates.

[0050] Figure 13 is a cross-sectional view showing the upper housing 11, rotating disk 14, fixed disk 13, rotating shaft 15, etc. in a simplified manner before operation. Figure 14 shows the rotating disk 14 and rotating shaft 15 in a cross-sectional view taken along line BB in Figure 13. Figures 13 and 14 show a state in which both the rotating disk 14 and the rotating shaft 15 are stopped and the upper and lower seal members 17, 18 are in contact with the upper housing 11 and fixed disk 13, respectively.

[0051] FIG. 15 is a cross-sectional view showing a simplified state in which the upper housing 11, rotating disk 14, fixed disk 13, and rotating shaft 15 start to rotate, with only the rotating shaft 15 starting to rotate. FIG. 16 is a cross-sectional view of the rotating disk 14 and the rotating shaft 15 taken along line CC in FIG. 15. FIGS. 15 and 16 show a state in which only the rotating shaft 15 rotates a predetermined angle in the through-hole 14a, causing the tip 15a of the rotating shaft 15 to press down on the fixed disk 13 due to the abutment between the shaft protrusion 15b and the disk recess 13e. At this time, the shaft protrusion 15b leaves the disk recess 13e and rides onto the disk protrusion 13g between the disk recesses 13e. As a result, the fixed disk 13 is pressed down against the biasing force of the spring 16, and the upper seal member 17 moves away from the upper housing 11, and the lower seal member 18 moves away from the fixed disk 13.

[0052] FIG. 17 is a cross-sectional view showing, in simplified form, the operating states of the upper housing 11, rotating disk 14, fixed disk 13, rotating shaft 15, etc. when the rotating shaft 15 rotates further. FIG. 18 is a cross-sectional view taken along line DD in FIG. 17 showing the rotating disk 14 and rotating shaft 15. In FIGS. 17 and 18, the rotating shaft 15 rotates further by a predetermined angle, causing the rotating disk 14 to rotate together with the rotation communicating passage 40. At this time, the rotating disk 14 rotates after the fixed disk 13 is pressed down. Furthermore, because the gap between the upper housing 11 and fixed disk 13 and the gap between the rotating disk 14 and fixed disk 13 are both widened, the sliding resistance of the upper seal member 17 and the lower seal member 18 when the rotating disk 14 rotates is reduced, and sliding wear of the upper and lower seal members 17, 18 is also reduced.

[0053] Figure 19 is a cross-sectional view showing a simplified state of the upper housing 11, rotating disk 14, fixed disk 13, rotating shaft 15, etc., after the rotating shaft 15 and rotating disk 14 have further rotated. Figure 20 is a cross-sectional view of the rotating disk 14 and rotating shaft 15 taken along line E-E in Figure 19. In Figures 19 and 20, the rotating shaft 15 rotates further a predetermined angle, causing the rotating disk 14 to rotate further a predetermined angle together with the rotation communicating passage 40. At this time, the shaft protrusions 15b of the rotating shaft 15 fit into the disk recesses 13e of the fixed disk 13, and the fixed disk 13 is pushed up by the biasing force of the spring 16, causing the upper seal member 17 to contact the upper housing 11 and the lower seal member 18 to contact the rotating disk 14.

[0054] According to the configuration of this embodiment, as described above, the rotating disk 14 rotates relative to the fixed disk 13 as the rotating shaft 15 rotates. At this time, sliding resistance associated with the rotation of the rotating disk 14 is reduced in the lower seal member 18 between the fixed disk 13 and the rotating disk 14. That is, according to the configuration described above, the tip end 15a of the rotating shaft 15 is provided so as to be able to abut and engage with the fixed disk 13, and the fixed disk 13 is configured to be able to move back and forth in the axial direction as the tip end 15a of the rotating shaft 15 abuts and engages with it as it rotates. Therefore, when the rotating disk 14 rotates in accordance with the rotation of the rotating shaft 15, the fixed disk 13 moves back and forth in the axial direction X, widening the gap between the upper housing 11 and the rotating disk 14 and the gap between the fixed disk 13 and the rotating disk 14. This reduces the surface pressure applied to the upper seal member 17 and the lower seal member 18 between the upper housing 11 and the rotating disk 14 and between the fixed disk 13 and the rotating disk 14, thereby reducing the sliding resistance of each seal member 17, 18. Therefore, when the rotary disk 14 rotates, the seal members 17 and 18 can be prevented from coming off due to sliding wear or getting caught.

[0055] Furthermore, according to the configuration of this embodiment, the rotating disk 14 and the rotating shaft 15 are connected to be relatively movable in the rotational direction and the axial direction X. Therefore, when the rotating disk 14 rotates and a surface pressure is applied to each of the seal members 17, 18, the rotating disk 14 moves in the rotational direction and the axial direction X within the gap between the housing 2 and the fixed disk 13, and is positioned at a position where the surface pressure applied to each of the seal members 17, 18 is balanced with the reaction force of each of the seal members 17, 18. Therefore, the surface pressure applied to each of the seal members 17, 18 when the rotating disk 14 rotates can be further reduced, and the durability of each of the seal members 17, 18 can be improved.

[0056] According to the configuration of this embodiment, seal members 17, 18 are provided between the housing 2 (upper housing 11) and the rotating disk 14 and between the rotating disk 14 and the fixed disk 13 in the axial direction X of the flow path switching device 1. Furthermore, in the axial direction X, elastic seal members 17, 18 are provided between the upper housing 11 and the rotating disk 14 and between the rotating disk 14 and the fixed disk 13, so that the rotating disk 14 is supported in a floating state by both the upper and lower seal members 17, 18. Therefore, when the rotating disk 14 rotates, the floating effect can suppress sliding resistance due to the application of fluid pressure, and the seal members 17, 18, which ensure the sealing of the rotary communicating passage 40 and the fixed communicating passage 50, can prevent uneven wear. This ensures that the seal members 17, 18 reliably prevent fluid leakage from the rotary communicating passage 40 and the fixed communicating passage 50. This ensures the sealing of the flow paths formed by the inlet flow path 20, the rotary communicating passage 40, and the fixed communicating passage 50.

[0057] Furthermore, according to the configuration of this embodiment, the seal members 17, 18 can also be used as elastic members for maintaining the positions of the fixed disk 13 and the rotating disk 14. This eliminates the need to provide a separate elastic member, suppressing an increase in the number of parts and enabling a reduction in the size of the flow path switching device 1. Furthermore, because the axial direction X of the fixed disk 13 and the rotating disk 14 and the sealing direction of the seal members 17, 18 are the same, sealing performance can be ensured even if a misalignment occurs in the central axis of the rotating disk 14 when it is rotated.

[0058] Furthermore, according to the configuration of this embodiment, the upper seal member 17, which is provided between the upper housing 11 and the rotating disk 14, and the lower seal member 18, which is provided between the rotating disk 14 and the fixed disk 13, are disposed at the same radial position of the rotating disk 14. Therefore, the rotation communication passage 40 is sealed by the seal members 17, 18 at the same position on both the upper end surface 14b and the lower end surface 14c of the rotating disk 14, and the area on which fluid pressure acts is the same at both the upper and lower end surfaces 14b, 14c of the rotating disk 14. Therefore, the fluid pressure acting on the upper end surface 14b and the lower end surface 14c is canceled, and only the biasing force of the spring 16 acts on the rotating disk 14, maintaining the orientation of the rotating disk 14. This reduces the sliding resistance between the rotating disk 14 and the fixed disk 13 when the rotating disk 14 rotates. As a result, the power of the drive unit 4, which drives the rotating disk 14 to rotate, can be reduced, thereby reducing the power consumption of the drive unit 4. Furthermore, since the load applied from the rotary disk 14 to the seal members 17 and 18 is reduced, the reliability of the sealing performance of the seal members 17 and 18 can be improved.

[0059] Furthermore, according to the configuration of this embodiment, at least a portion of the cylindrical portion 13b of the fixed disk 13 is inserted inside the outflow passage 30. This prevents circumferential positional displacement of the fixed disk 13 caused by the rotational driving of the rotating disk 14. Furthermore, since the direction in which the rotating disk 14 may be misaligned (i.e., the left-right direction intersecting the axial direction X) differs from the sealing direction of the sealing members 17, 18 (i.e., the axial direction X), even if the rotating disk 14 is misaligned, the sealing performance of the sealing members 17, 18 is maintained.

[0060] According to the configuration of this embodiment, the upper seal member 17, which is provided between the upper housing 11 and the rotating disk 14, and the lower seal member 18, which is provided between the rotating disk 14 and the fixed disk 13, are positioned at the same radial position of the rotating disk 14. Therefore, even if the rotating disk 14 is tilted due to fluid pressure or the like, the repulsive force of each seal member 17, 18 can return the rotating disk 14 to a horizontal position. Furthermore, each seal member 17, 18 applies uniform surface pressure to the upper housing 11 and the fixed disk 13 in the circumferential direction while sealing them. This reduces the sliding resistance of each seal member 17, 18 and causes uniform wear. As a result, the rotating disk 14 can be maintained in a horizontal position even after aging.

[0061] According to the configuration of this embodiment, the connection portion between the rotating shaft 15 and the rotating disk 14 (the portion where the rotating shaft 15 and the through hole 14a correspond) has a gap 28 in the rotation direction, so when the rotating shaft 15 is rotated, the rotating shaft 15 rotates idly by the gap 28 at the connection portion. Therefore, even when the rotating shaft 15 is rotated, the rotating disk 14 does not rotate, and it is possible to set a state in which the gap between the upper housing 11 and the rotating disk 14 and the gap between the fixed disk 13 and the rotating disk 14 are widened. As a result, it is possible to provide a section in which the gap between the upper housing 11 and the rotating disk 14 and the gap between the fixed disk 13 and the rotating disk 14 are widened before the rotating shaft 15 is driven to rotate.

[0062] Second Embodiment Next, the second embodiment will be described in detail with reference to Figures 21 to 39(D). In the following description, the same components as those in the first embodiment will be denoted by the same reference numerals and description thereof will be omitted, and the following description will focus on the differences.

[0063] [About the sliding resistance reduction structure] The flow path switching device 1 of this embodiment has the same external appearance and internal basic structure as the first embodiment, but differs from the first embodiment in the configuration of the above-mentioned "sliding resistance reducing structure." FIG. 21 is a plan view of the flow path switching device 1 of this embodiment with the upper housing 11 and drive unit 4 removed. FIG. 22 is an enlarged plan view of the through hole 14a and the rotating shaft 15 (encircled by the dashed line) in FIG. 21. FIG. 23 is a perspective view of the rotating shaft 15 of this embodiment. FIG. 24 is an enlarged perspective view of the engagement structure K1 at the tip of the rotating shaft 15 shown in FIG. 23. FIG. 25 is a plan view of the fixed disk 13 of this embodiment. FIG. 26 is an enlarged perspective view of the engagement structure K2 of the fixed disk 13 shown in FIG. 25.

[0064] In this embodiment, the basic configurations of the fixed disk 13, rotating disk 14, rotating shaft 15, upper seal member 17 and lower seal member 18 are the same as those of the first embodiment, but as shown in Figures 21 to 26, it differs from the first embodiment in the cross-sectional shape of the through hole 14a of the rotating disk 14, the shape of the part of the rotating shaft 15 that engages with the through hole 14a, and the configurations of the engaging structure K1 of the rotating shaft 15 and the engaged structure K2 of the fixed disk 13.

[0065] That is, as shown in FIG. 22 , the cross-sectional shape of the through hole 14a is a butterfly shape with two sectors arranged rotationally symmetrically around the axis of the through hole 14a. The cross-sectional shape of the portion of the rotating shaft 15 that engages with the through hole 14a is a two-sided shape (oval) that allows rotation within the through hole 14a. In this embodiment, the connection portion between the rotating shaft 15 and the rotating disk 14 (the portion where the rotating shaft 15 and the through hole 14a correspond) has a predetermined gap 28 between the rotating shaft 15 and the inner wall of the through hole 14a. When the rotating shaft 15 receives driving force from the drive unit 4 and rotates, it rotates idle in the through hole 14a by the amount of the gap 28, and then engages with the inner wall of the through hole 14a to rotate integrally with the rotating disk 14.

[0066] As shown in Figures 23 and 24, the engagement structure K1 provided at the tip of the rotating shaft 15 has a shape substantially identical to that of the first embodiment and includes four recesses (shaft recesses) 15c and four protrusions (shaft protrusions) 15b arranged in the circumferential direction. The shaft protrusions 15b are arranged at equal angular intervals (90°), and the shaft recesses 15c are formed between the shaft protrusions 15b. Each shaft recess 15c and each shaft protrusion 15b includes a side surface 15d that slopes in the circumferential direction (arrangement direction). In this embodiment, the apex 15e of each shaft protrusion 15b is formed as a convex curved surface that protrudes outward, and includes side surfaces 15d that slope to both sides of the apex 15e. The inclination angles of both side surfaces 15d are set to the same angle. These side surfaces 15d are also side surfaces of the shaft recess 15c. Furthermore, the bottom of each shaft recess 15c is flat.

[0067] On the other hand, as shown in Figures 25 and 26, the engagement structure K2 provided at the center of the upper surface 13d of the fixed disk 13 includes four convex portions (disk convex portions) 13g and four concave portions (disk concave portions) 13e that can abut and engage with the shaft concave portion 15c and the shaft convex portion 15b as the rotating shaft 15 rotates. The disk convex portions 13g are arranged at equal angular intervals (90°), and the disk concave portions 13e are located between the disk convex portions 13g. In this embodiment, each disk convex portion 13g includes side portions 13i that slope in the circumferential direction (arrangement direction) on both sides of the top portion 13h. The inclination angles of both side portions 13i are set to the same angle. These side portions 13i are also side portions of the disk concave portion 13e. Furthermore, the bottom of each disk concave portion 13e is flat.

[0068] [Switching flow path patterns] The flow path switching device 1 of this embodiment has the above-described configuration, and is therefore capable of switching the flow path of the fluid between four patterns. Figures 27(A) to 39(D) show operational diagrams related to switching the flow path pattern.

[0069] First, FIGS. 27(A) to 27(D) show the "initial state" of the flow path switching device 1 of this embodiment, and FIG. 27(A) is a conceptual diagram showing the engagement relationship between the through-hole 14a of the rotary disk 14 and the rotary shaft 15. Each of (A) in FIGS. 28 to 39 (described later) is a conceptual diagram equivalent to FIG. 27(A). FIG. 27(B) is a conceptual diagram showing the change in lift (push-up) of the rotary shaft 15 relative to the rotation angle (rotation shaft angle) of the rotary shaft 15. In FIG. 27(B), the thick peaks and valleys correspond to the disk protrusions 13g and disk recesses 13e, respectively, and the black dots correspond to the positions of the shaft protrusions 15b (the same applies to similar figures described later). Each of (B) in FIGS. 28 to 39 (described later) is a conceptual diagram equivalent to FIG. 27(B). Fig. 27(C) is a plan view showing the rotational positions of the through-hole 14a and the rotary shaft 15, and the positional relationship between the disk protrusion 13g, the disk recess 13e, and the shaft protrusion 15b. Each of Figs. 28 to 39 (C) described later is a plan view equivalent to Fig. 27(C). Fig. 27(D) is a plan view equivalent to Fig. 21 showing the rotational positions of the rotary disc 14 and the rotation communicating passage 40. In Fig. 27(D), the reference line L1 indicated by a thick dashed line indicates the reference position on the rotary disc 14 (the same applies to similar figures described later). Each of Figs. 28 to 39 (D) described later is a plan view equivalent to Fig. 27(D).

[0070] In this "initial state," as shown in FIG. 27(A), the rotating shaft 15 engages with one inner wall of the through-hole 14a, and as shown in FIG. 27(B), the rotating shaft 15 is lifted down. Also, as shown in FIG. 27(C), the shaft protrusion 15b rides down on the disk recess 13e. Furthermore, the rotating disk 14 and the rotation communicating passage 40 are disposed in the state shown in FIG. 27(D). At this time, the first rotation communicating passage 41 communicates with the second inlet flow path 22 and the second fixed communicating passage 52, the second rotation communicating passage 42 communicates with the third inlet flow path 23 and the third fixed communicating passage 53, the third rotation communicating passage 43 communicates with the fourth inlet flow path 24 and the fourth fixed communicating passage 54, and the fourth rotation communicating passage 44 communicates with the first inlet flow path 21 and the first fixed communicating passage 51. The rotation angle of the rotary disc 14 at this time (disc rotation angle) is defined as "0°", and this flow path switching state is defined as "pattern A".

[0071] Next, we will explain the changes from the "initial state" one by one. Figures 28(A) to 28(D) show a "45° rotated state" in which the rotating shaft 15 has rotated "45°" clockwise from the "initial state." In this state, as shown in Figure 28(A), the rotating shaft 15 rotates 45° clockwise from the "initial state" and engages with the other inner wall of the through-hole 14a, and as shown in Figure 28(B), the rotating shaft 15 is lifted up. Also, as shown in Figure 28(C), the shaft protrusion 15b rides on the disk protrusion 13g. Furthermore, as shown in Figure 28(D), the disk rotation angle remains "0°," and the flow path switching state of the rotation communicating passage 40 is "Pattern A," the same as in the "initial state."

[0072] As described above, in this embodiment, when the tip of the rotating shaft 15 moves from an engaging state to an abutting state with the fixed disk 13, that is, when the shaft protrusion 15b moves from the disk recess 13e onto the disk protrusion 13g, the "idling angle" at which the rotating shaft 15 rotates idly in the clockwise direction is set to "45°." Also, in this embodiment, in the "initial state" shown in Figure 27(A), the rotating shaft 15 is a "one-side idling type" that can rotate idly only in the clockwise direction.

[0073] Next, Figures 29(A) to 29(D) show a "90° rotated state" in which the rotating shaft 15 has rotated another 45° clockwise from the "45° rotated state." In this state, as shown in Figure 29(A), the rotating shaft 15 rotates 45° clockwise together with the rotating disc 14, and as shown in Figure 29(B), the rotating shaft 15 is lifted down. Also, as shown in Figure 29(C), the shaft protrusion 15b rides down on the disc recess 13e. Furthermore, as shown in Figure 29(D), the rotation communicating passage 40 has rotated 45° clockwise. In this "90° rotation state," first rotation communicating passage 41 communicates with second inflow passage 22 and third fixed communicating passage 53, second rotation communicating passage 42 communicates with third inflow passage 23 and fourth fixed communicating passage 54, third rotation communicating passage 43 communicates with fourth inflow passage 24 and first fixed communicating passage 51, and fourth rotation communicating passage 44 communicates with first inflow passage 21 and second fixed communicating passage 52. The disc rotation angle at this time is "45°," and this flow passage switching state is defined as "Pattern B." In other words, between the "45° rotation state" and the "90° rotation state," the lift-down of rotation shaft 15 and switching of the flow passages occur simultaneously.

[0074] As described above, in this embodiment, the "switching angle" for rotating the rotary disk 14 to switch the flow paths of the flow path switching device 1 is set to "45°." That is, in this embodiment, the "idle rotation angle" of the rotating shaft 15 in the clockwise direction and the "switching angle" of the rotary disk 14 for switching the flow paths are set to the same value of "45°."

[0075] Next, Figures 30(A) to 30(D) show a "135° rotated state" in which the rotating shaft 15 has rotated a further "45°" clockwise from the "90° rotated state." In this state, as shown in Figure 30(A), the rotating shaft 15 rotates "45°" clockwise together with the rotating disc 14, and as shown in Figure 30(B), the rotating shaft 15 is lifted up. Also, as shown in Figure 30(C), the shaft protrusion 15b rides on the disc protrusion 13g. Furthermore, as shown in Figure 30(D), the rotation communicating passage 40 has rotated "45°" clockwise. In this "135° rotation state," the first rotation communicating passage 41 communicates with the third inflow passage 23 and the third fixed communicating passage 53, the second rotation communicating passage 42 communicates with the fourth inflow passage 24 and the fourth fixed communicating passage 54, the third rotation communicating passage 43 communicates with the first inflow passage 21 and the first fixed communicating passage 51, and the fourth rotation communicating passage 44 communicates with the second inflow passage 22 and the second fixed communicating passage 52. The disc rotation angle at this time is "90°," and this flow passage switching state is defined as "Pattern C." In other words, between the "90° rotation state" and the "135° rotation state," the lift-up of the rotary shaft 15 and the switching of the flow passages occur simultaneously.

[0076] Next, Figures 31(A) to 31(D) show a "90° return rotation state" in which the rotating shaft 15 has rotated counterclockwise by "45°" from the "135° rotation state." In this state, as shown in Figure 31(A), the rotating shaft 15 rotates counterclockwise by "45°" and engages with one of the inner walls of the through-hole 14a, and as shown in Figure 31(B), the rotating shaft 15 is lifted down. Also, as shown in Figure 31(C), the shaft protrusion 15b rides down on the disc recess 13e. Furthermore, as shown in Figure 31(D), the rotation communicating passage 40 remains in the same position as in the "135° rotation state," and the disc rotation angle remains at "90°." The flow path switching state at this time is "Pattern C," the same as in the "135° rotation state."

[0077] As described above, in this embodiment, the "idle rotation angle" at which the rotating shaft 15 rotates counterclockwise when the shaft protrusion 15b moves from the disk protrusion 13g onto the disk recess 13e is also set to "45°." That is, in this embodiment, the "idle rotation angle" of the rotating shaft 15 in the counterclockwise direction and the "switching angle" of the rotating disk 14 for switching the flow path are also set to the same value of "45°."

[0078] Next, Figures 32(A) to 32(D) show a "135° re-rotation state" in which the rotating shaft 15 has rotated "45°" clockwise from the "90° return rotation state." In this state, as shown in Figure 32(A), the rotating shaft 15 rotates idly "45°" clockwise and engages with the other inner wall of the through-hole 14a, and as shown in Figure 32(B), the rotating shaft 15 is lifted up. Also, as shown in Figure 32(C), the shaft protrusion 15b rides on the disk protrusion 13g. Furthermore, as shown in Figure 32(D), the rotation communicating passage 40 remains in the same position as in the "90° return rotation state," and the disk rotation angle remains at "90°." The flow path switching state at this time is "Pattern C."

[0079] Next, Figures 33(A) to 33(D) show a "180° rotated state" in which the rotating shaft 15 has rotated "45°" clockwise from the "135° re-rotated state." In this state, as shown in Figure 33(A), the rotating shaft 15 rotates "45°" clockwise together with the rotating disc 14, and as shown in Figure 33(B), the rotating shaft 15 is lifted down. Also, as shown in Figure 33(C), the shaft protrusion 15b rides down on the disc recess 13e. Furthermore, as shown in Figure 33(D), the rotation communicating passage 40 has rotated another "45°" clockwise. In this "180° rotation state," the first rotation communicating passage 41 communicates with the third inflow passage 23 and the fourth fixed communicating passage 54, the second rotation communicating passage 42 communicates with the fourth inflow passage 24 and the first fixed communicating passage 51, the third rotation communicating passage 43 communicates with the first inflow passage 21 and the second fixed communicating passage 52, and the fourth rotation communicating passage 44 communicates with the second inflow passage 22 and the third fixed communicating passage 53. The disc rotation angle at this time is "135°," and this flow passage switching state is defined as "Pattern D." In other words, between the "135° rotation state" and the "180° rotation state," the lift-down of the rotary shaft 15 and the switching of the flow passages occur simultaneously.

[0080] Next, Figures 34(A) to 34(D) show a "135° return rotation state" in which the rotating shaft 15 has rotated 45° counterclockwise from the "180° rotation state." In this state, as shown in Figure 34(A), the rotating shaft 15 rotates 45° counterclockwise and engages with one of the inner walls of the through-hole 14a, and as shown in Figure 34(B), the rotating shaft 15 is lifted up. Also, as shown in Figure 34(C), the shaft protrusion 15b rides on the disk protrusion 13g. Furthermore, as shown in Figure 34(D), the rotation communicating passage 40 remains in the same position as in the "180° rotation state," and the disk rotation angle remains at 135°. The flow path switching state at this time is "Pattern D," the same as in the "180° rotation state."

[0081] Next, Figures 35(A) to 35(D) show a "90° back rotation state" in which the rotating shaft 15 has rotated "45°" counterclockwise from the "135° back rotation state." In this state, as shown in Figure 35(A), the rotating shaft 15 rotates "45°" counterclockwise together with the rotating disc 14, and as shown in Figure 35(B), the rotating shaft 15 is lifted down. Also, as shown in Figure 35(C), the shaft protrusion 15b is lowered onto the disc recess 13e. Furthermore, as shown in Figure 35(D), the rotation communicating passage 40 is in the same position as in the "135° back rotation state," and the disc rotation angle is "90°." The flow path switching state at this time is "pattern C," the same as the "135° back rotation state." In other words, between the "135° back rotation state" and the "90° back rotation state," the lifting down of the rotating shaft 15 and the flow path switching are performed simultaneously.

[0082] Next, Figures 36(A) to 36(D) show a "45° back rotation state" in which the rotating shaft 15 is further rotated counterclockwise by "45°" from the "90° back rotation state." In this state, as shown in Figure 36(A), the rotating shaft 15 rotates counterclockwise by "45°" together with the rotating disc 14, and as shown in Figure 36(B), the rotating shaft 15 is lifted up. Also, as shown in Figure 36(C), the shaft protrusion 15b rides on the disc protrusion 13g. Furthermore, as shown in Figure 36(D), the rotation communicating passage 40 is in the same position as in the "90° rotation state," and the disc rotation angle is "45°." The flow path switching state at this time is "Pattern B," the same as in the "90° rotation state." In other words, between the "90° back rotation state" and the "45° back rotation state," the lifting up of the rotating shaft 15 and the flow path switching occur simultaneously.

[0083] Next, Figures 37(A) to 37(D) show a "90° re-rotation state" in which the rotating shaft 15 has rotated "45°" clockwise from the "45° return rotation state." In this state, as shown in Figure 37(A), the rotating shaft 15 rotates idly clockwise "45°" and engages with the other inner wall of the through-hole 14a, and as shown in Figure 37(B), the rotating shaft 15 is lifted down. Also, as shown in Figure 37(C), the shaft protrusion 15b rides down on the disc recess 13e. Furthermore, as shown in Figure 37(D), the rotation communicating passage 40 remains in the same position as in the "45° return rotation state," and the disc rotation angle remains at "45°." The flow path switching state at this time is "Pattern B," the same as in the "45° return rotation state."

[0084] Next, Figures 38(A) to 38(D) show a "45° return rotation state" in which the rotating shaft 15 has rotated 45° counterclockwise from the "90° re-rotation state." In this state, as shown in Figure 38(A), the rotating shaft 15 rotates 45° counterclockwise and engages with one of the inner walls of the through-hole 14a, and as shown in Figure 38(B), the rotating shaft 15 is lifted up. Also, as shown in Figure 38(C), the shaft protrusion 15b rides on the disk protrusion 13g. Furthermore, as shown in Figure 38(D), the rotation communicating passage 40 remains in the same position as in the "90° re-rotation state," and the disk rotation angle remains at 45°. The flow path switching state at this time is "Pattern B."

[0085] 39(A) to 39(D) show the "return initial state" in which the rotating shaft 15 has rotated counterclockwise by 45° from the "return 45° rotated state." In this state, as shown in FIG. 39(A), the rotating shaft 15 rotates counterclockwise by 45° together with the rotating disc 14, and as shown in FIG. 39(B), the rotating shaft 15 is lifted down. Also, as shown in FIG. 39(C), the shaft protrusion 15b rides down on the disc recess 13e. Furthermore, as shown in FIG. 39(D), the rotation communicating passage 40 returns to the same position as in the "initial state," and the disc rotation angle is 0°. The flow path switching state at this time is "pattern A," the same as the "initial state." In other words, between the "return 45° rotated state" and the "return initial state," the lifting down of the rotating shaft 15 and the switching of the flow path occur simultaneously.

[0086] [About the function and effect of the flow path switching device] The configuration of flow path switching device 1 of this embodiment described above provides the following functions and effects in addition to the functions and effects of the first embodiment. That is, with the configuration of flow path switching device 1, by rotating rotating shaft 15, a state in which shaft protrusion 15b and disk protrusion 13g abut (protrusion-protrusion abutment state) and a state in which shaft protrusion 15b and shaft recess 15c engage with disk recess 13e and disk protrusion 13g (protrusion-recess engagement state) are obtained. Here, in the protrusion-protrusion abutment state, fixed disk 13 moves axially, widening the gap between upper housing 11 and rotating disk 14 and the gap between fixed disk 13 and rotating disk 14, thereby reducing the surface pressure applied to upper seal member 17 and lower seal member 18 between upper housing 11 and rotating disk 14 and between fixed disk 13 and rotating disk 14. In contrast, in the convex-concave engagement state, fixed disk 13 moves axially, returning the gaps between upper housing 11 and rotating disk 14 and between fixed disk 13 and rotating disk 14 to their original levels, and the surface pressure applied to upper seal member 17 and lower seal member 18 between upper housing 11 and rotating disk 14 and between fixed disk 13 and rotating disk 14 returns to its original state. Switching between the convex-concave abutment state and the convex-concave engagement state goes through a state in which shaft convex portion 15b and shaft concave portion 15c come into contact with the inclined side surfaces 13i, 15d of disk concave portion 13e and disk convex portion 13g, respectively. This allows for smooth switching between the convex-convex abutment state and the convex-concave engagement state.

[0087] According to the configuration of this embodiment, when the shaft protrusion 15b and the disk protrusion 13g are in contact with each other, the top 15e of the shaft protrusion 15b is formed into a convex curved surface, so that when the rotating shaft 15 is rotated from this state, the axial position of the rotating shaft 15 does not change suddenly. Furthermore, because the bottoms of the disk recess 13e and the shaft recess 15c are formed into a flat surface, the axial position of the rotating shaft 15 does not change suddenly when the rotating shaft 15 is rotated with the shaft protrusion 15b and the shaft recess 15c engaged with the disk recess 13e and the disk protrusion 13g. This makes it possible to further suppress sliding wear of the lower seal member 18.

[0088] According to the configuration of this embodiment, when the shaft protrusion 15b moves from the disk recess 13e onto the disk protrusion 13g, i.e., when the fixed disk 13 moves axially and the gap between the upper housing 11 and the rotating disk 14 and the gap between the fixed disk 13 and the rotating disk 14 widen, the idle angle of the rotating shaft 15 and the switching angle of the rotating disk 14 when switching the flow paths are set to the same angle (45°). Therefore, by rotating the rotating shaft 15 counterclockwise (in the opposite direction) through the switching angle and the idle angle (45°), the rotational positions of the rotating shaft 15 and the rotating disk 14 can be returned to their original states. Therefore, the flow path switching operation when the rotating shaft 15 is rotated clockwise (in one direction) can be made to coincide with the flow path switching operation when the rotating shaft 15 is rotated counterclockwise.

[0089] In this embodiment, as shown in Figures 29(A) to 29(D), 33(A) to 33(D), 35(A) to 35(D), and 39(A) to 39(D), when the rotating disk 14 rotates, the rotating shaft 15 lifts down (the fixed disk 13 and the rotating disk 14 return to their original spacing). Therefore, when the flow path is switched, the surface pressure applied to the seal members 17, 18 between the upper housing 11 and the rotating disk 14 and between the fixed disk 13 and the rotating disk 14 is reduced, making it possible to prevent the seal members 17, 18 from coming off due to sliding wear or getting caught. The same is true when the rotating disk 14 rotates and the rotating shaft 15 lifts up (the spacing between the fixed disk 13 and the rotating disk 14 widens) as shown in Figures 30(A) to 30(D) and 36(A) to 36(D).

[0090] In this embodiment, in a configuration in which only one side is idling and the flow path can be switched between two patterns, the clockwise "idling angle" of the rotating shaft 15 and the "switching angle" of the flow path are set to the same value of 45°. Therefore, as shown in Figures 29(A) to 29(D), 33(A) to 33(D), 35(A) to 35(D), and 39(A) to 39(D), when switching the flow path, the rotating shaft 15 is lifted up, and then the flow path switching and the lifting down of the rotating shaft 15 are performed simultaneously. This allows the drive torque of the rotating shaft 15 (drive torque of the drive unit 4) to be reduced, and the drive unit 4 (motor) can be made smaller.

[0091] In this embodiment, as in the first embodiment, a predetermined gap 28 is provided at the connection between the rotating shaft 15 and the rotating disk 14 (between the rotating shaft 15 and the inner wall of the through-hole 14a). When the rotating shaft 15 receives driving force from the drive unit 4 and rotates, it rotates freely in the through-hole 14a by the amount of the gap 28, and then engages with the inner wall of the through-hole 14a to rotate integrally with the rotating disk 14. Therefore, even when the rotating shaft 15 is rotated, the rotating disk 14 does not rotate, and the gap between the upper housing 11 and the rotating disk 14 and the gap between the fixed disk 13 and the rotating disk 14 can be set to a wide state. As a result, the rotating disk 14 can be lifted up or down without rotating.

[0092] Assume now that there is no gap in the rotational direction at the connection between the rotating shaft and the rotating disk. For example, assume that the rotating disk is configured to rotate 45° to switch the flow path. In this case, the rotating shaft needs to be lifted up and down while the rotating disk is rotated 45° to switch the flow path. In this case, the rotating shaft is rotated 22.5° to lift up the rotating shaft. In order to increase the lift amount of the rotating shaft at this time, the driving torque of the rotating shaft needs to be increased. In other words, if the driving torque of the rotating shaft is not increased, the lift amount of the rotating shaft cannot be increased. As a result, the reduction in surface pressure of the seal member during flow path switching is reduced. In contrast, in this embodiment, by providing a gap 28 in the rotational direction of the rotating shaft 15, i.e., by allowing the rotating shaft 15 to rotate idly, the lift amount of the rotating shaft 15 (the increase in the gap between the fixed disk 13 and the rotating disk 14) can be increased without significantly increasing the driving torque of the rotating shaft 15 (the driving torque of the drive unit 4).

[0093] <Third embodiment> Next, the third embodiment will be described in detail with reference to FIGS. 40(A) to 44(C).

[0094] The flow path switching device 1 of this embodiment is basically the same in appearance and internal structure as those of the first embodiment, but differs from the second embodiment in the configuration of the above-mentioned "sliding resistance reduction structure", i.e., the engaging structure K1 and the engaged structure K2.

[0095] [Switching flow path patterns] Due to the difference in configuration as described above, the flow path switching device 1 of this embodiment is capable of switching the fluid flow path between two patterns. Figures 40(A) to 44(C) show operational diagrams related to switching the flow path pattern. The flow path switching device 1 of this embodiment is of the "one-side idling type" as in the second embodiment.

[0096] First, Figures 40(A) to 40(C) show the "initial state" of the flow path switching device 1 of this embodiment, and Figure 40(A) is an image diagram showing the engagement relationship between the through-hole 14a of the rotary disc 14 and the rotary shaft 15. Each of Figures 41 to 44 (A) described later is an image diagram equivalent to Figure 40(A). Figure 40(B) is an image diagram showing the change in lift of the rotary shaft 15 with respect to the rotary shaft angle. Each of Figures 41 to 44 (B) described later is an image diagram equivalent to Figure 40(B). Figure 40(C) is a plan view equivalent to Figure 21 showing the rotational positions of the rotary disc 14 and the rotation communicating passage 40. Each of Figures 41 to 44 (C) described later is a plan view equivalent to Figure 40(C).

[0097] In this "initial state," as shown in FIG. 40(A), the rotating shaft 15 engages with one inner wall of the through-hole 14a, and the shaft protrusion 15b rides down into the disk recess 13e, causing the rotating shaft 15 to be lifted down as shown in FIG. 40(B). The rotating disc 14 and the rotation communicating passage 40 are disposed in the state shown in FIG. 40(C). The disc rotation angle at this time is "0°," and the flow path switching state is the same as "pattern A" in the second embodiment.

[0098] Next, changes from the "initial state" will be explained one by one. Figures 41(A) to 41(C) show a "45° rotated state" in which the rotating shaft 15 has rotated "45°" clockwise from the "initial state." In this state, as shown in Figure 41(A), the rotating shaft 15 rotates idly "45°" clockwise from the "initial state" and engages with the other inner wall of the through-hole 14a, and the shaft protrusion 15b rides on the disk protrusion 13g, thereby lifting up the rotating shaft 15 as shown in Figure 41(B). Also, as shown in Figure 41(C), the disk rotation angle remains "0°," and the flow path switching state of the rotation communicating passage 40 is "pattern A," the same as in the "initial state."

[0099] As described above, in this embodiment as well, the "idling angle" at which the rotary shaft 15 is idling clockwise when the shaft protrusion 15b rides on the disk protrusion 13g is set to "45°."

[0100] Next, Figures 42(A) to 42(C) show a "90° rotated state" in which the rotating shaft 15 is rotated clockwise by a further "45°" from the "45° rotated state." In this state, as shown in Figure 42(A), the rotating shaft 15 rotates clockwise by "45°" together with the rotating disc 14, and the shaft protrusion 15b rides down into the disc recess 13e, causing the rotating shaft 15 to lift down as shown in Figure 42(B). Also, as shown in Figure 42(C), the disc rotation angle is "45°," and the flow path switching state of the rotation communicating passage 40 is the same as "pattern B" of the second embodiment. That is, between the "45° rotated state" and the "90° rotated state," the lift down of the rotating shaft 15 and the flow path switching are performed simultaneously.

[0101] As described above, in this embodiment as well, the "idling angle" of the rotating shaft 15 in the clockwise direction and the "switching angle" for switching the flow path are set to the same value of "45°."

[0102] Next, Figures 43(A) to 43(C) show a "45° return rotation state" in which the rotating shaft 15 has rotated "45°" counterclockwise from the "90° rotation state." In this state, as shown in Figure 43(A), the rotating shaft 15 rotates counterclockwise by "45°" and engages with one inner wall of the through-hole 14a, and the shaft protrusion 15b rides on the disk protrusion 13g, thereby lifting up the rotating shaft 15 as shown in Figure 43(B). Also, as shown in Figure 43(C), the disk rotation angle is "45°," and the flow path switching state of the rotation communicating passage 40 is "Pattern B," the same as in the "90° rotation state."

[0103] 44(A) to 44(C) show a "return initial state" in which the rotating shaft 15 has rotated counterclockwise by a further "45°" from the "return 45° rotated state." In this state, as shown in FIG. 44(A), the rotating shaft 15 rotates counterclockwise by "45°" together with the rotating disc 14, and the shaft protrusion 15b rides down into the disc recess 13e, thereby lifting down the rotating shaft 15 as shown in FIG. 44(B). Also, as shown in FIG. 44(C), the disc rotation angle is "0°," and the flow path switching state of the rotation communicating passage 40 is "pattern A," the same as the "initial state."

[0104] [About the function and effect of the flow path switching device] The flow path switching device 1 of this embodiment described above differs in configuration from the second embodiment, which can switch the fluid flow path between four patterns, in that it can switch between two patterns, but it can achieve the same functions and effects as the second embodiment.

[0105] In this embodiment, as shown in Figures 42(A) to 42(C) and 44(A) to 44(C), when the rotating disk 14 rotates (when the flow path switches), the rotating shaft 15 lifts down (the fixed disk 13 and the upper housing 11 return to their original distance). Therefore, when the rotating disk 14 rotates, the surface pressure applied to the seal members 17, 18 between the fixed disk 13 and the upper housing 11 is reduced, and it can be seen that the seal members 17, 18 can be prevented from coming off due to sliding wear or getting caught.

[0106] In this embodiment, in a configuration in which only one side is idling and the flow path can be switched between two patterns, the clockwise "idling angle" of the rotating shaft 15 and the "switching angle" of the flow path are set to the same value of "45°." Therefore, as shown in Figures 42(A) to 42(C) and 44(A) to 44(C), when switching the flow path, the rotating shaft 15 is lifted up, and then the flow path switching and the lifting down of the rotating shaft 15 are performed simultaneously. This allows the drive torque of the rotating shaft 15 (drive torque of the drive unit 4) to be reduced, and the drive unit 4 (motor) to be made smaller.

[0107] <Fourth embodiment> Next, the fourth embodiment will be described in detail with reference to FIGS. 45(A) to 49(C).

[0108] The flow path switching device 1 of this embodiment differs from the third embodiment in the configuration of the above-mentioned "sliding resistance reducing structure", that is, in the engaging structure K1 and the engaged structure K2.

[0109] [Switching flow path patterns] The flow path switching device 1 of this embodiment, like the third embodiment, is capable of switching the flow path of the fluid between two patterns. Figures 45(A) to 49(C) show operational diagrams related to switching the flow path pattern. The flow path switching device 1 of this embodiment is of the "one-side idling type" as in the third embodiment.

[0110] First, Figures 45(A) to 45(C) show the "initial state" of the flow path switching device 1 of this embodiment, and Figure 45(A) is an image diagram showing the engagement relationship between the through-hole 14a of the rotary disc 14 and the rotary shaft 15. Each of Figures 46 to 49 (A) described later is an image diagram equivalent to Figure 45(A). Figure 45(B) is an image diagram showing the change in lift of the rotary shaft 15 with respect to the rotary shaft angle. Each of Figures 46 to 49 (B) described later is an image diagram equivalent to Figure 45(B). Figure 45(C) is a plan view equivalent to Figure 21 showing the rotational positions of the rotary disc 14 and the rotation communicating passage 40. Each of Figures 46 to 49 (C) described later is a plan view equivalent to Figure 45(C).

[0111] In this "initial state," as shown in FIG. 45(A), the rotating shaft 15 engages with one inner wall of the through-hole 14a, and the shaft protrusion 15b rides down into the disk recess 13e, so that the rotating shaft 15 is lifted down as shown in FIG. 45(B). The rotating disc 14 and the rotation communicating passage 40 are disposed in the state shown in FIG. 45(C). The disc rotation angle at this time is "0°," and the flow path switching state is the same as "pattern A" in the third embodiment.

[0112] Next, changes from the "initial state" will be explained one by one. Figures 46(A) to 46(C) show a "22.5° rotated state" in which the rotating shaft 15 has rotated "22.5°" clockwise from the "initial state." In this state, as shown in Figure 46(A), the rotating shaft 15 rotates idly "22.5°" clockwise from the "initial state" and engages with the other inner wall of the through-hole 14a, and the shaft protrusion 15b rides on the disk protrusion 13g, thereby lifting up the rotating shaft 15 as shown in Figure 46(B). Also, as shown in Figure 46(C), the disk rotation angle is "0°," and the flow path switching state of the rotation communicating passage 40 is "pattern A," the same as in the "initial state."

[0113] As described above, in this embodiment, the "idling angle" at which the rotary shaft 15 is idling clockwise when the shaft protrusion 15b rides on the disk protrusion 13g is set to "22.5°."

[0114] Next, Figures 47(A) to 47(C) show a "67.5° rotation state" in which the rotating shaft 15 has rotated "45°" clockwise from the "22.5° rotation state." In this state, as shown in Figure 47(A), the rotating shaft 15 rotates "45°" clockwise together with the rotating disc 14, and the shaft protrusion 15b rides down onto the disc recess 13e, causing the rotating shaft 15 to lift down as shown in Figure 47(B). Also, as shown in Figure 47(C), the disc rotation angle is "45°," and the flow path switching state of the rotation communication passage 40 is the same as "pattern B" of the third embodiment. That is, between the "22.5° rotation state" and the "67.5° rotation state," the lift down of the rotating shaft 15 and the flow path switching are performed simultaneously.

[0115] In this embodiment, the "switching angle" for rotating the rotary disk 14 to switch the flow path is set to "45°." That is, in this embodiment, the "switching angle" for switching the flow path is set to an angle greater than the "idle angle" of the rotation shaft 15 in the clockwise direction.

[0116] Next, Figures 48(A) to 48(C) show a "45° return rotation state" in which the rotating shaft 15 has rotated counterclockwise by "22.5°" from the "67.5° rotation state." In this state, as shown in Figure 48(A), the rotating shaft 15 rotates counterclockwise by "22.5°" and engages with one inner wall of the through-hole 14a, and the shaft protrusion 15b begins to move toward the disk protrusion 13g, thereby lifting the rotating shaft 15 partway up as shown in Figure 48(B). Also, as shown in Figure 48(C), the disk rotation angle remains at "45°," and the flow path switching state of the rotation communicating passage 40 is "Pattern B," the same as in the "67.5° rotation state."

[0117] 49(A) to 49(C) show a "return initial state" in which the rotating shaft 15 has rotated counterclockwise by "45°" from the "return 45° rotated state." In this state, as shown in FIG. 49(A), the rotating shaft 15 rotates counterclockwise by "45°" together with the rotating disc 14, and the shaft protrusion 15b rides over the disc protrusion 13g and rides down on the disc recess 13e, causing the rotating shaft 15 to lift up and down as shown in FIG. 49(B). Also, as shown in FIG. 49(C), the disc rotation angle is "0°," and the flow path switching state of the rotation communication passage 40 is "pattern A," the same as the "initial state." In other words, between the "return 45° rotated state" and the "return initial state," the lift up and lift down of the rotating shaft 15 and the flow path switching are performed simultaneously.

[0118] [About the function and effect of the flow path switching device] According to the configuration of the flow path switching device 1 of this embodiment described above, as in the third embodiment, the fluid flow path is configured to be switchable between two patterns, and the rotating shaft 15 is of the "one-side idling type," so it is possible to obtain the same functions and effects as the third embodiment. However, in this embodiment, the "switching angle" of the flow path is different from the "idling angle" of the rotating shaft 15, so the operation of the rotating disk 14 and the rotating shaft 15 when switching the flow path is different from the third embodiment.

[0119] In this embodiment, as shown in Figures 47(A) to 47(C), when the rotating disk 14 rotates, the rotating shaft 15 lifts down (the gap between the fixed disk 13 and the upper housing 11 returns to its original state), and as shown in Figures 49(A) to 49(C), the rotating shaft 15 lifts up and down (the gap between the fixed disk 13 and the upper housing 11 widens once and then returns to its original state). As a result, when the rotating disk 14 rotates, the surface pressure applied to the seal members 17, 18 between the fixed disk 13 and the rotating disk 14 is reduced, making it possible to prevent the seal members 17, 18 from coming off due to sliding wear or getting caught.

[0120] Fifth Embodiment Next, the fifth embodiment will be described in detail with reference to FIGS. 50(A) to 58(C).

[0121] [Switching flow path patterns] The flow path switching device 1 of this embodiment differs from the second embodiment in that the flow path switching pattern of the fluid can be switched between three patterns. Figures 50(A) to 58(C) show operational diagrams related to flow path pattern switching. The flow path switching device 1 of this embodiment is the same "one-side idling type" as the second embodiment.

[0122] First, Figures 50(A) to 50(C) show the "initial state" of the flow path switching device 1 of this embodiment, and Figure 50(A) is an image diagram showing the engagement relationship between the through-hole 14a of the rotary disc 14 and the rotary shaft 15. Each of Figures 51 to 58 (A) described later is an image diagram equivalent to Figure 50(A). Figure 50(B) is an image diagram showing the change in lift of the rotary shaft 15 with respect to the rotary shaft angle. Each of Figures 51 to 58 (B) described later is an image diagram equivalent to Figure 50(B). Figure 50(C) is a plan view equivalent to Figure 21 showing the rotational positions of the rotary disc 14 and the rotation communicating passage 40. Each of Figures 51 to 58 (C) described later is a plan view equivalent to Figure 50(C).

[0123] In this "initial state," as shown in FIG. 50(A), the rotating shaft 15 engages with one inner wall of the through-hole 14a, and the shaft protrusion 15b rides down into the disk recess 13e, causing the rotating shaft 15 to be lifted down as shown in FIG. 50(B). The rotating disc 14 and the rotation communicating passage 40 are positioned as shown in FIG. 50(C). The disc rotation angle at this time is "0°," and the flow path switching state is the same as "pattern A" in the third embodiment.

[0124] Next, changes from the "initial state" will be explained one by one. Figures 51(A) to 51(C) show a "45° rotated state" in which the rotating shaft 15 has rotated "45°" clockwise from the "initial state." In this state, as shown in Figure 51(A), the rotating shaft 15 rotates idly "45°" clockwise from the "initial state" and engages with the other inner wall of the through-hole 14a, and the shaft protrusion 15b rides up on the disk protrusion 13g, thereby lifting up the rotating shaft 15 as shown in Figure 51(B). Also, as shown in Figure 51(C), the disk rotation angle remains "0°," and the flow path switching state of the rotation communicating passage 40 is "pattern A," the same as in the "initial state."

[0125] Next, Figures 52(A) to 52(C) show a "90° rotated state" in which the rotating shaft 15 is rotated clockwise by a further "45°" from the "45° rotated state." In this state, as shown in Figure 52(A), the rotating shaft 15 rotates clockwise by "45°" together with the rotating disc 14, and the shaft protrusion 15b rides down into the disc recess 13e, causing the rotating shaft 15 to lift down as shown in Figure 52(B). Also, as shown in Figure 52(C), the disc rotation angle is "45°," and the flow path switching state of the rotation communicating passage 40 is the same as "pattern B" of the second embodiment. That is, between the "45° rotated state" and the "90° rotated state," the lift down of the rotating shaft 15 and the flow path switching are performed simultaneously.

[0126] As described above, in this embodiment, the "switching angle" for switching the flow path and the "idling angle" of the rotating shaft 15 in the clockwise direction are the same, ie, "45°."

[0127] Next, Figures 53(A) to 53(C) show a "135° rotation state" in which the rotating shaft 15 has rotated a further "45°" clockwise from the "90° rotation state." In this state, as shown in Figure 53(A), the rotating shaft 15 rotates clockwise by "45°" together with the rotating disc 14, and the shaft protrusion 15b rides up onto the disc protrusion 13g, thereby lifting up the rotating shaft 15 as shown in Figure 53(B). Also, as shown in Figure 53(C), the disc rotation angle is "90°," and the flow path switching state of the rotation communication passage 40 is the same as "pattern C" of the second embodiment. That is, between the "90° rotation state" and the "135° rotation state," the lifting up of the rotating shaft 15 and the switching of the flow path occur simultaneously.

[0128] Next, Figures 54(A) to 54(C) show a "90° return rotation state" in which the rotating shaft 15 has rotated "45°" counterclockwise from the "135° rotation state." In this state, as shown in Figure 54(A), the rotating shaft 15 rotates idly counterclockwise by "45°" and engages with one inner wall of the through-hole 14a, and the shaft protrusion 15b rides down into the disk recess 13e, thereby lifting the rotating shaft 15 down as shown in Figure 54(B). Also, as shown in Figure 54(C), the disk rotation angle remains "90°," and the flow path switching state of the rotation communicating passage 40 is "pattern C."

[0129] Next, Figures 55(A) to 55(C) show a "45° back rotation state" in which the rotating shaft 15 has rotated "45°" counterclockwise from the "90° back rotation state." In this state, as shown in Figure 55(A), the rotating shaft 15 rotates "45°" counterclockwise together with the rotating disc 14, and the shaft protrusion 15b rides up onto the disc protrusion 13g, causing the rotating shaft 15 to be lifted up as shown in Figure 55(B). Also, as shown in Figure 55(C), the disc rotation angle is "45°," and the flow path switching state of the rotation communicating passage 40 is "pattern B." In other words, between the "90° back rotation state" and the "45° back rotation state," the lifting up of the rotating shaft 15 and the switching of the flow path occur simultaneously.

[0130] Next, Figures 56(A) to 56(C) show a "re-rotated 90° state" in which the rotating shaft 15 has rotated "45°" clockwise from the "returned 45° state." In this state, as shown in Figure 56(A), the rotating shaft 15 idles "45°" clockwise and engages with the other inner wall of the through-hole 14a, and the shaft protrusion 15b rides down into the disc recess 13e, thereby lifting the rotating shaft 15 down as shown in Figure 56(B). Also, as shown in Figure 56(C), the disc rotation angle remains "45°," and the flow path switching state of the rotation communicating passage 40 remains "pattern B."

[0131] Next, Figures 57(A) to 57(C) show a "45° return rotation state" in which the rotating shaft 15 has rotated counterclockwise by "45°" from the "90° re-rotation state." In this state, as shown in Figure 57(A), the rotating shaft 15 rotates counterclockwise by "45°" and engages with one inner wall of the through-hole 14a, and the shaft protrusion 15b rides up onto the disk protrusion 13g, thereby lifting up the rotating shaft 15 as shown in Figure 57(B). Also, as shown in Figure 57(C), the disk rotation angle remains at "45°," and the flow path switching state of the rotation communicating passage 40 remains at "pattern B."

[0132] 58(A) to 58(C) show a "return initial state" in which the rotating shaft 15 has rotated counterclockwise by 45° from the "return 45° rotated state." In this state, as shown in FIG. 58(A), the rotating shaft 15 rotates counterclockwise by 45° together with the rotating disc 14, and the shaft protrusion 15b rides down into the disc recess 13e, causing the rotating shaft 15 to lift down as shown in FIG. 58(B). Also, as shown in FIG. 58(C), the disc rotation angle returns to 0°, and the flow path switching state of the rotation communicating passage 40 is "pattern A," the same as the "initial state." In other words, between the "return 45° rotated state" and the "return initial state," the lift down of the rotating shaft 15 and the flow path switching are performed simultaneously.

[0133] [About the function and effect of the flow path switching device] The configuration of the flow path switching device 1 of this embodiment described above differs from that of the second embodiment in that the flow path of the fluid can be switched between three patterns.

[0134] In this embodiment, as shown in Figures 52(A) to 52(C) and 58(A) to 58(C), when the rotating disk 14 rotates, the rotating shaft 15 lifts down (the fixed disk 13 and the upper housing 11 return to their original distance). Therefore, when the rotating disk 14 rotates, the surface pressure applied to the seal members 17, 18 between the fixed disk 13 and the upper housing 11 is reduced, and it can be seen that the removal of the seal members 17, 18 due to sliding wear or snagging can be suppressed.

[0135] In this embodiment, in a configuration in which only one side is idling and the flow path can be switched between three patterns, the clockwise "idling angle" of the rotating shaft 15 and the "switching angle" of the flow path are set to the same "45°". Therefore, as shown in Figures 52(A) to 52(C) and Figures 58(A) to 58(C), when switching the flow path, the rotating shaft 15 is lifted up, and then the flow path switching and the lifting down of the rotating shaft 15 are performed simultaneously. This allows the drive torque of the rotating shaft 15 (drive torque of the drive unit 4) to be reduced, and the drive unit 4 (motor) can be made smaller.

[0136] Sixth Embodiment Next, the sixth embodiment will be described in detail with reference to FIGS.

[0137] [Appearance of the flow path switching device] Figure 59 shows a perspective view of the top side of flow path switching device 8 of this embodiment. Figure 60 shows a perspective view of the bottom side of flow path switching device 8. Figure 61 shows a plan view of flow path switching device 8. Figure 62 shows a plan view of flow path switching device 8 with the upper housing 11 and drive unit 4 removed. This embodiment differs from the previous embodiments in the arrangement of inflow flow paths 20 in the upper housing 11, the arrangement of outflow flow paths 30 in the lower housing 12, the shape and arrangement of rotary communicating passages 40 in the rotating disk 14, and the arrangement of fixed communicating passages 50 in the fixed disk 13.

[0138] That is, as shown in Figures 59 and 61, in this embodiment, the four inflow passages 20 (21-24) are arranged biasedly on approximately one half of the upper surface of the upper housing 11, and adjacent inflow passages 20 (21-24) are arranged at equal angular intervals (60°). Also, as shown in Figure 60, in this embodiment, the four outflow passages 30 (31-34) are arranged biasedly on approximately one half of the upper surface of the lower housing 12, corresponding to the four inflow passages 20 (21-24), and adjacent adjacent passages are arranged at equal angular intervals (60°).

[0139] 62, the rotation communicating passages 40 provided in the rotary disc 14 have first to third rotation communicating passages 41 to 43 that are all short, curved passages, with only the fourth rotation communicating passage 44 having a long, curved shape. The upper seal members 17 provided around each rotation communicating passage 40 have shapes that match the shapes of the corresponding rotation communicating passages 40 (41 to 44). The lower seal member 18 is similar to the upper seal member 17.

[0140] In this embodiment, the flow path switching device 8 further includes a control unit 5 that controls the drive unit 4 to switch the flow path of the fluid, as shown in Fig. 59. The control unit 5 stores a predetermined control program and controls the drive unit 4 to execute "flow path switching control" described later.

[0141] [About the sliding resistance reduction structure] The flow path switching device 8 of this embodiment also differs from the previous embodiments in the configuration of the "sliding resistance reducing structure." Fig. 63 shows an enlarged plan view of the through hole 14a and the rotating shaft 15 of Fig. 62. Fig. 64 shows a perspective view of the rotating shaft 15 of this embodiment. Fig. 65 shows an enlarged perspective view of the engaging structure K1 at the tip of the rotating shaft 15 shown in Fig. 64. Fig. 66 shows a plan view of the fixed disk 13 of this embodiment. Fig. 67 shows an enlarged perspective view of the engaged structure K2 of the fixed disk 13 shown in Fig. 66.

[0142] In this embodiment, the basic configurations of the fixed disk 13, rotating disk 14, rotating shaft 15, upper seal member 17, and lower seal member 18 are similar to those of the previous embodiments except for the arrangement and shape of the inlet flow passages 20, outlet flow passages 30, and rotary communicating passages 40, but the configuration differs in the following respects: That is, as shown in Figure 66, the arrangement of the fixed communicating passages 50 (51-54) of the fixed disk 13 is biased to approximately one half of the upper surface of the fixed disk 13 so as to match the arrangement of the outlet flow passages 30 of the lower housing 12, and adjacent adjacent passages are spaced at equal angular intervals (60°).

[0143] This embodiment also differs from the previous embodiments in the configuration of the engagement structure K1 at the tip of the rotating shaft 15 and the engaged structure K2 of the fixed disk 13. That is, as shown in Figures 64 and 65, the engagement structure K1 provided at the tip of the rotating shaft 15, unlike the previous embodiments, includes two shaft protrusions 15b and two shaft recesses 15c aligned in the circumferential direction. The two shaft protrusions 15b are spaced apart at equal angles (180°), and a shaft recess 15c is formed between the shaft protrusions 15b. Each shaft protrusion 15b has the same shape as in the previous embodiments, but the circumferential length of the bottom of each shaft recess 15c is longer than in the previous embodiments.

[0144] On the other hand, as shown in Figures 66 and 67, the disk protrusions 13g and disk recesses 13e that constitute the engaged structure K2 of the fixed disk 13 are arranged at equal angular intervals (90°). Each disk protrusion 13g includes a side surface 13i that slopes in its circumferential direction (arrangement direction). The slope angles of both side surfaces 13i are set to be the same. These side surfaces 13i also form side surfaces of the disk recesses 13e. In this embodiment, each disk protrusion 13g has a flat top 13h, and both sides of the top 13h form sloped side surfaces 13i. Furthermore, the bottom of each disk recess 13e is flat.

[0145] [Switching flow path patterns] The flow path switching device 8 of this embodiment has the above-described configuration, and is therefore capable of switching the flow path of the fluid between three patterns. Figures 68(A) to 80(D) show operational diagrams related to the switching of the flow path pattern.

[0146] First, Figures 68(A) to 68(D) show the "initial state" of the flow path switching device 8 of this embodiment, and Figure 68(A) is a conceptual diagram showing the engagement relationship between the through-hole 14a of the rotary disk 14 and the rotary shaft 15. Each of Figures 69 to 80 (described later) (A) is a conceptual diagram equivalent to Figure 68A. Figure 68(B) is a conceptual diagram showing the change in lift of the rotary shaft 15 with respect to the rotary shaft angle. Each of Figures 69 to 80 (described later) (B) is a conceptual diagram equivalent to Figure 68(B). Figure 68(C) is a plan view showing the rotational positions of the through-hole 14a and the rotary shaft 15, and the positional relationship between the disk protrusion 13g, the disk recess 13e, and the shaft protrusion 15b. Each of Figures 69 to 80 (described later) (C) is a plan view equivalent to Figure 68(C). Figure 68(D) is a plan view equivalent to Figure 62, showing the rotational positions of the rotary disc 14 and the rotation communicating path 40. Each of (D) in Figures 69 to 80, which will be described later, is a plan view equivalent to Figure 68(D).

[0147] In this "initial state," as shown in FIG. 68(A), the rotating shaft 15 is positioned in a state in which there are gaps 28 on both sides of the through-hole 14a in the rotational direction, and as shown in FIG. 68(B), the rotating shaft 15 is lifted down. Also, as shown in FIG. 68(C), the shaft protrusion 15b rests on the disk recess 13e. Furthermore, the rotating disk 14 and the rotation communicating passage 40 are disposed in the state shown in FIG. 68(D). At this time, the first rotation communicating passage 41 communicates with the first inflow passage 21 and the first fixed communicating passage 51, the second rotation communicating passage 42 communicates with the second inflow passage 22 and the second fixed communicating passage 52, the third rotation communicating passage 43 communicates with the third inflow passage 23 and the third fixed communicating passage 53, and the fourth rotation communicating passage 44 communicates with the fourth inflow passage 24 and the fourth fixed communicating passage 54. The disk rotation angle at this time is defined as "0°," and this flow path switching state is defined as "pattern A."

[0148] Next, we will explain the changes from the "initial state" one by one. Figures 69(A) to 69(D) show the "30° rotated state" in which the rotating shaft 15 has rotated "30°" clockwise from the "initial state." In this state, as shown in Figure 69(A), the rotating shaft 15 rotates idly clockwise "30°" from the "initial state" and engages with one inner wall of the through-hole 14a, and as shown in Figure 69(B), the rotating shaft 15 is lifted up. Also, as shown in Figure 69(C), the shaft protrusion 15b rides on one side edge of the top 13h of the disk protrusion 13g. Furthermore, as shown in Figure 69(D), the disk rotation angle remains "0°," and the flow path switching state of the rotation communicating passage 40 is "Pattern A," the same as in the "initial state."

[0149] As described above, in this embodiment, the "idling angle" at which the rotating shaft 15 is idling clockwise when the shaft protrusion 15b moves from the disk recess 13e onto the disk protrusion 13g is set to "30°." Also, in this embodiment, in the "initial state" shown in Figure 68(A), the rotating shaft 15 is positioned in the through-hole 14a with gaps 28 on both sides in the rotation direction, so the rotating shaft 15 is a "double-sided idling type" that can idly rotate in both the clockwise and counterclockwise directions.

[0150] Next, Figures 70(A) to 70(D) show a "60° rotated state" in which the rotating shaft 15 has rotated another "30°" clockwise from the "30° rotated state." In this state, as shown in Figure 70(A), the rotating shaft 15 rotates "30°" clockwise together with the rotating disc 14, and as shown in Figure 70(B), the rotating shaft 15 rotates clockwise while remaining lifted up. Also, as shown in Figure 70(C), the shaft protrusion 15b rides on the other side edge of the top 13h of the disc protrusion 13g. Furthermore, as shown in Figure 70(D), the rotation communicating passage 40 has rotated "30°" clockwise. In this "60° rotation state," first rotation communicating passage 41 communicates with second inflow passage 22 and first fixed communicating passage 51, second rotation communicating passage 42 communicates with third inflow passage 23 and second fixed communicating passage 52, third rotation communicating passage 43 communicates with fourth inflow passage 24 and third fixed communicating passage 53, and fourth rotation communicating passage 44 communicates with first inflow passage 21 and fourth fixed communicating passage 54. The disc rotation angle at this time is "30°," and this flow passage switching state is defined as "Pattern B." In other words, between the "30° rotation state" and the "60° rotation state," the rotation shaft 15 is held lifted up and the flow passages are switched simultaneously.

[0151] As described above, in this embodiment, the "switching angle" by which the rotary disk 14 is rotated to switch the flow paths of the flow path switching device 8 is set to "30°." That is, in this embodiment, the "idle rotation angle" of the rotating shaft 15 in the clockwise direction and the "switching angle" of the rotary disk 14 for switching the flow paths are set to the same value of "30°."

[0152] Next, Figures 71(A) to 71(D) show a "30° rotation return state" in which the rotating shaft 15 has rotated counterclockwise by 30° from the "60° rotation state." In this state, as shown in Figure 71(A), the rotating shaft 15 idles counterclockwise by 30°, and as shown in Figure 71(B), the rotating shaft 15 rotates counterclockwise while remaining lifted up. Also, as shown in Figure 71(C), the shaft protrusion 15b rides on one side edge of the apex 13h of the disk protrusion 13g. Furthermore, as shown in Figure 71(D), the rotation communicating passage 40 remains in the same position as in the "60° rotation state," and the disk rotation angle remains at 30°. The flow path switching state at this time is "Pattern B," the same as in the "60° rotation state."

[0153] Next, Figures 72(A) to 72(D) show the "0° return rotation state" in which the rotating shaft 15 has rotated a further 30° counterclockwise from the "30° return rotation state." In this state, as shown in Figure 72(A), the rotating shaft 15 rotates idly counterclockwise by 30° and engages with one of the inner walls of the through-hole 14a, and as shown in Figure 72(B), the rotating shaft 15 is lifted down. Also, as shown in Figure 72(C), the shaft protrusion 15b rides down on the disc recess 13e. Furthermore, as shown in Figure 72(D), the rotation communicating passage 40 remains in the same position as in the "30° return rotation state," and the disc rotation angle remains at 30°. The flow path switching state at this time is "Pattern B," the same as the "60° rotation state."

[0154] Next, Figures 73(A) to 73(D) show a "30° re-rotation state" in which the rotating shaft 15 has rotated "30°" clockwise from the "0° return rotation state." In this state, as shown in Figure 73(A), the rotating shaft 15 idles "30°" clockwise from the "0° return rotation state," and as shown in Figure 73(B), the rotating shaft 15 is lifted up. Also, as shown in Figure 73(C), the shaft protrusion 15b rides on one side edge of the apex 13h of the disk protrusion 13g. Furthermore, as shown in Figure 73(D), the rotation communicating passage 40 remains in the same position as in the "0° return rotation state," and the disk rotation angle remains at "30°." The flow path switching state at this time is "Pattern B," the same as the "0° return rotation state."

[0155] Next, Figures 74(A) to 74(D) show a "60° re-rotation state" in which the rotating shaft 15 has rotated "30°" clockwise from the "30° re-rotation state." In this state, as shown in Figure 74(A), the rotating shaft 15 rotates idly "30°" clockwise and engages with the other inner wall of the through-hole 14a. As shown in Figure 74(B), the rotating shaft 15 rotates clockwise while remaining lifted up. Also, as shown in Figure 74(C), the shaft protrusion 15b rides on the other side edge of the apex 13h of the disk protrusion 13g. Furthermore, as shown in Figure 74(D), the rotation communicating passage 40 remains in the same position as in the "30° re-rotation state," and the disk rotation angle remains at "30°." The flow path switching state at this time is "Pattern B," the same as in the "30° re-rotation state."

[0156] Next, Figures 75(A) to 75(D) show a "90° rotated state" in which the rotating shaft 15 has rotated "30°" clockwise from the "60° re-rotated state." In this state, as shown in Figure 75(A), the rotating shaft 15 rotates "30°" clockwise together with the rotating disc 14, and as shown in Figure 75(B), the rotating shaft 15 is lifted down. Also, as shown in Figure 75(C), the shaft protrusion 15b rides down from the top 13h of the disc protrusion 13g onto the disc recess 13e. Furthermore, as shown in Figure 74(D), the rotation communicating passage 40 has rotated "30°" clockwise. In this "90° rotated state," first rotation communicating passage 41 communicates with second inflow passage 22 and second fixed communicating passage 52, second rotation communicating passage 42 communicates with third inflow passage 23 and third fixed communicating passage 53, third rotation communicating passage 43 communicates with fourth inflow passage 24 and fourth fixed communicating passage 54, and fourth rotation communicating passage 44 communicates with first inflow passage 21 and first fixed communicating passage 51. The disc rotation angle at this time is "60°," and the passage switching state at this time is defined as "pattern C." In other words, between the "re-60° rotated state" and the "90° rotated state," rotary shaft 15 is lifted down and the passages are switched simultaneously.

[0157] Next, Figures 76(A) to 76(D) show a "60° return rotation state" in which the rotating shaft 15 has rotated counterclockwise by 30° from the "90° rotation state." In this state, as shown in Figure 76(A), the rotating shaft 15 idles counterclockwise by 30°, and as shown in Figure 76(B), the rotating shaft 15 is lifted up. Also, as shown in Figure 76(C), the shaft protrusion 15b rides on the other side edge of the top 13h of the disk protrusion 13g. Furthermore, as shown in Figure 76(D), the rotation communicating passage 40 remains in the same position as in the "90° rotation state," and the disk rotation angle remains at 60°. The flow path switching state at this time is "Pattern C," the same as in the "90° rotation state."

[0158] Next, Figures 77(A) to 77(D) show a "30° back rotation state" in which the rotating shaft 15 has rotated counterclockwise by 30° from the "60° back rotation state." In this state, as shown in Figure 77(A), the rotating shaft 15 rotates counterclockwise by 30° and engages with one inner wall of the through-hole 14a. As shown in Figure 77(B), the rotating shaft 15 rotates counterclockwise while remaining lifted up. Also, as shown in Figure 77(C), the shaft protrusion 15b rides on one side edge of the apex 13h of the disk protrusion 13g. Furthermore, as shown in Figure 77(D), the rotation communicating passage 40 remains in the same position as in the "60° back rotation state," and the disk rotation angle remains at 60°. The flow path switching state at this time is "Pattern C," the same as the "60° back rotation state."

[0159] Next, Figures 78(A) to 78(D) show a "0° return rotation state" in which the rotating shaft 15 has rotated "30°" counterclockwise from the "30° return rotation state." In this state, as shown in Figure 78(A), the rotating shaft 15 rotates "30°" counterclockwise together with the rotating disc 14, and as shown in Figure 78(B), the rotating shaft 15 is lifted down. Also, as shown in Figure 78(C), the shaft protrusion 15b rides down on the disc recess 13e. Furthermore, as shown in Figure 78(D), the rotation communicating passage 40 has rotated "30°" counterclockwise. The disc rotation angle at this time is "30°," and the flow path switching state is "pattern B." In other words, between the "30° return rotation state" and the "0° return rotation state," the lifting down of the rotating shaft 15 and the flow path switching are performed simultaneously.

[0160] Next, Figures 79(A) to 79(D) show a "-30° rotation state" in which the rotating shaft 15 has rotated counterclockwise by "30°" from the "return 0° rotation state." In this state, as shown in Figure 79(A), the rotating shaft 15 rotates counterclockwise by "30°" together with the rotating disc 14, and as shown in Figure 79(B), the rotating shaft 15 is lifted up. Also, as shown in Figure 79(C), the shaft protrusion 15b rides on the disc protrusion 13g. Furthermore, as shown in Figure 79(D), the rotation communicating passage 40 has rotated counterclockwise by "30°." At this time, the disc rotation angle is "0°," and the flow path switching state is "pattern A." In other words, between the "return 0° rotation state" and the "-30° rotation state," the lifting up of the rotating shaft 15 and the flow path switching are performed simultaneously.

[0161] 80(A) to 80(D) show the "return initial state" in which the rotating shaft 15 has rotated "30°" clockwise from the "-30° rotation state." In this state, as shown in FIG. 80(A), the rotating shaft 15 rotates idly "30°" clockwise, and as shown in FIG. 80(B), the rotating shaft 15 is lifted down. Also, as shown in FIG. 80(C), the shaft protrusion 15b is lowered onto the disc recess 13e. Furthermore, as shown in FIG. 80(D), the rotation communicating passage 40 remains in the same position as in the "initial state," and the disc rotation angle is "0°." The flow path switching state at this time is "pattern A," the same as the "initial state."

[0162] [Flow path switching control] Next, the "flow path switching control" executed by the control unit 5 of the flow path switching device 8 of this embodiment will be described. Figures 81 to 83 show an example of the control content using flowcharts.

[0163] When the process proceeds to this control routine, the control unit 5 acquires the rotation angle (rotation shaft angle) Sdeg of the rotation shaft 15 in step 100. Here, a first angle sensor (not shown) that detects the rotation shaft angle Sdeg is provided in the housing 2 of the flow path switching device 8, and the control unit 5 acquires the rotation shaft angle Sdeg based on the detection value of the angle sensor.

[0164] Next, in step 110, the control unit 5 determines whether or not there is a request to switch the flow path. This request can be assumed to be issued, for example, by a control device that controls the fluid circuit in which the flow path switching device 8 is provided. If the result of this determination is positive, the control unit 5 proceeds to step 120, and if the result of this determination is negative, the control unit 5 proceeds to step 220.

[0165] In step 220, the control unit 5 holds the switching position of the flow path switching device 8 and returns the process to step 100.

[0166] In step 120, the control unit 5 acquires the stop angle (pre-switching disk stop angle) TSTA of the rotating disk 14 before switching. Here, a second angle sensor (not shown) that detects the disk rotation angle is provided in the housing 2 of the flow path switching device 8, and the control unit 5 acquires the pre-switching disk stop angle TSTA based on the detection value of the angle sensor.

[0167] In step 130, the control unit 5 acquires the stop angle (switching request disk stop angle) TSTO of the rotating disk 14 for which switching is requested. It can be assumed that this switching request disk stop angle TSTO is transmitted, for example, by a control device that controls a fluid circuit in which the flow path switching device 8 is provided.

[0168] Next, in step 140, the control unit 5 determines whether the pre-switching disc stop angle TSTA is "0 deg," i.e., "0°." If the result of this determination is affirmative, the control unit 5 proceeds to step 150, and if the result of this determination is negative, the control unit 5 proceeds to step 320.

[0169] In step 150, the control unit 5 determines whether the switching request disc stop angle TSTO is "30 deg," i.e., "30°." If the result of this determination is affirmative, the control unit 5 proceeds to step 160, and if the result of this determination is negative, the control unit 5 proceeds to step 280.

[0170] In step 160, the control unit 5 determines whether the reversal control flag XRC is "0." As will be described later, the control unit 5 sets this flag XRC to "1" when the rotating shaft 15 is rotated counterclockwise, and to "0" when the rotating shaft 15 is rotated clockwise. If the result of this determination is positive, the control unit 5 proceeds to step 170, and if the result of this determination is negative, the control unit 5 proceeds to step 230.

[0171] In step 170, the control unit 5 controls the drive unit 4 to drive the rotation shaft 15 to rotate clockwise.

[0172] Next, in step 180, the control unit 5 determines whether the rotation axis angle Sdeg is "60deg," i.e., "60°" or greater. If the result of this determination is positive, the control unit 5 proceeds to step 190, and if the result of this determination is negative, the control unit 5 returns the process to step 100.

[0173] In step 190, the control unit 5 controls the drive unit 4 to stop the clockwise drive of the rotation shaft 15.

[0174] Next, in step 200, the control unit 5 controls the drive unit 4 to drive the rotation shaft 15 to rotate counterclockwise.

[0175] Next, in step 210, the control unit 5 sets the reversal control flag XRC to "1."

[0176] On the other hand, in step 230, moving from step 160, the control unit 5 determines whether the rotation shaft angle Sdeg is "0deg," i.e., "0°" or less. If the result of this determination is positive, the control unit 5 proceeds to step 240, and if the result of this determination is negative, the control unit 5 returns the process to step 100.

[0177] Next, in step 240, the control unit 5 controls the drive unit 4 to stop the counterclockwise drive of the rotation shaft 15.

[0178] Next, in step 250, the control unit 5 sets the pre-switching disc stop angle TSTA to "30 deg", that is, "30°".

[0179] Next, in step 260, the control unit 5 sets the reversal control flag XRC to "0."

[0180] Next, in step 270, the control unit 5 completes the switching of the flow path, i.e., cancels the switching request, and returns the process to step 100.

[0181] On the other hand, in step 280 following step 150, the control unit 5 controls the drive unit 4 to drive the rotation shaft 15 to rotate clockwise.

[0182] Next, in step 290, the control unit 5 determines whether the rotation axis angle Sdeg is "90deg," i.e., "90°" or greater. If the result of this determination is positive, the control unit 5 proceeds to step 300, and if the result of this determination is negative, the control unit 5 returns the process to step 100.

[0183] In step 300, the control unit 5 controls the drive unit 4 to stop the clockwise drive of the rotation shaft 15.

[0184] Next, in step 310, the control unit 5 sets the pre-switching disc stop angle TSTA to "60 deg", that is, "60°", and proceeds to step 260.

[0185] On the other hand, in step 320, moving from step 140, the control unit 5 determines whether the pre-switching disc stop angle TSTA is "30 degrees." If the result of this determination is affirmative, the control unit 5 proceeds to step 330, and if the result of this determination is negative, the control unit 5 proceeds to step 470.

[0186] Then, moving from step 320 to step 330, the control unit 5 determines whether the switching request disc stop angle TSTO is "0 deg," i.e., "0°." If the result of this determination is positive, the control unit 5 proceeds to step 340, and if the result of this determination is negative, the control unit 5 proceeds to step 400.

[0187] In step 340, the control unit 5 determines whether the reversal control flag XRC is 0. If the result of this determination is positive, the control unit 5 proceeds to step 350, and if the result of this determination is negative, the control unit 5 proceeds to step 440.

[0188] In step 350, the control unit 5 controls the drive unit 4 to drive the rotation shaft 15 to rotate counterclockwise.

[0189] Next, in step 360, the control unit 5 determines whether the rotation axis angle Sdeg is "-30deg," i.e., "-30°" or less. If the result of this determination is positive, the control unit 5 proceeds to step 370, and if the result of this determination is negative, the control unit 5 returns the process to step 100.

[0190] In step 370, the control unit 5 controls the drive unit 4 to stop the counterclockwise drive of the rotation shaft 15.

[0191] Next, in step 380, the control unit 5 controls the drive unit 4 to drive the rotation shaft 15 to rotate clockwise.

[0192] Next, in step 390, the control unit 5 sets the reversal control flag XRC to “1” and returns the process to step 100.

[0193] On the other hand, in step 400 following step 330, the control unit 5 controls the drive unit 4 to drive the rotation shaft 15 to rotate clockwise.

[0194] Next, in step 410, the control unit 5 determines whether the rotation axis angle Sdeg is equal to or greater than 90deg. If the result of this determination is affirmative, the control unit 5 proceeds to step 420, and if the result of this determination is negative, the control unit 5 returns to step 100.

[0195] In step 420, the control unit 5 controls the drive unit 4 to stop the clockwise drive of the rotation shaft 15.

[0196] Next, in step 430, the control unit 5 sets the pre-switching disc stop angle TSTA to "60 degrees" and moves the process to step 260.

[0197] On the other hand, in step 440, moving from step 340, the control unit 5 determines whether the rotation shaft angle Sdeg is equal to or greater than 0deg. If the determination result is positive, the control unit 5 proceeds to step 450, and if the determination result is negative, the control unit 5 returns to step 100.

[0198] In step 450, the control unit 5 controls the drive unit 4 to stop the clockwise drive of the rotation shaft 15.

[0199] Next, in step 460, the control unit 5 sets the pre-switching disc stop angle TSTA to "0 degrees" and moves the process to step 260.

[0200] On the other hand, in step 470, moving from step 320, the control unit 5 determines whether the switching request disc stop angle TSTO is "0 degrees." If the result of this determination is affirmative, the control unit 5 proceeds to step 480, and if the result of this determination is negative, the control unit 5 proceeds to step 540.

[0201] In step 480, the control unit 5 determines whether the reversal control flag XRC is 0. If the result of this determination is positive, the control unit 5 proceeds to step 490, and if the result of this determination is negative, the control unit 5 proceeds to step 580.

[0202] In step 490, the control unit 5 controls the drive unit 4 to drive the rotation shaft 15 to rotate counterclockwise.

[0203] Next, in step 500, the control unit 5 determines whether the rotation axis angle Sdeg is equal to or less than "-30deg." If the result of this determination is affirmative, the control unit 5 proceeds to step 510, and if the result of this determination is negative, the control unit 5 returns the process to step 100.

[0204] In step 510, the control unit 5 controls the drive unit 4 to stop the counterclockwise rotation of the rotation shaft 15.

[0205] Next, in step 520, the control unit 5 controls the drive unit 4 to drive the rotation shaft 15 to rotate clockwise.

[0206] Next, in step 530, the control unit 5 sets the reversal control flag XRC to “1” and returns the process to step 100.

[0207] On the other hand, moving from step 470 to step 540, the control unit 5 controls the drive unit 4 to drive the rotation shaft 15 to rotate counterclockwise.

[0208] Next, in step 550, the control unit 5 determines whether the rotation shaft angle Sdeg is equal to or less than 0deg. If the result of this determination is affirmative, the control unit 5 proceeds to step 560, and if the result of this determination is negative, the control unit 5 returns the process to step 100.

[0209] In step 560, the control unit 5 controls the drive unit 4 to stop the counterclockwise rotation of the rotation shaft 15.

[0210] Next, in step 570, the control unit 5 sets the pre-switching disc stop angle TSTA to "30 degrees" and moves the process to step 260.

[0211] On the other hand, in step 580, moving from step 480, the control unit 5 determines whether the rotation shaft angle Sdeg is equal to or greater than 0deg. If the result of this determination is positive, the control unit 5 proceeds to step 590, and if the result of this determination is negative, the control unit 5 returns the process to step 100.

[0212] In step 590, the control unit 5 controls the drive unit 4 to stop the clockwise drive of the rotation shaft 15.

[0213] Next, in step 600, the control unit 5 sets the pre-switching disc stop angle TSTA to "0 degrees" and moves the process to step 260.

[0214] In this embodiment, the drive unit 4 corresponds to an example of the "drive means" of the disclosed technology, and the control unit 5 corresponds to an example of the "control means" of the disclosed technology. The control unit 5 controls the drive unit 4 to rotate the rotating shaft 15 clockwise, switch the flow path when the tip of the rotating shaft 15 abuts against the fixed disk 13, i.e., when the crest 15e of the shaft protrusion 15b abuts against the crest 13h of the disk protrusion 13g, and then rotate the rotating shaft 15 counterclockwise (in the reverse direction), and stop the rotation of the rotating shaft 15 when the tip of the rotating shaft 15 engages with the fixed disk 13, i.e., when the shaft recess 15c and the shaft protrusion 15b engage with the disk protrusion 13g and the disk recess 13e.

[0215] [About the function and effect of the flow path switching device] According to the configuration of the flow path switching device 8 of this embodiment described above, the control unit 5 controls the drive unit 4 to rotate the rotating shaft 15, switching the flow path when the top 15e of the shaft protrusion 15b and the top 13h of the disk protrusion 13g are in contact (widening the gap between the upper housing 11 and the rotating disk 14 and the gap between the fixed disk 13 and the rotating disk 14), and then rotating the rotating shaft 15 counterclockwise (in the reverse direction) to stop the rotation of the rotating shaft 15 when the shaft protrusion 15b and the shaft recess 15c are engaged with the disk recess 13e and the disk protrusion 13g (returning the gap between the upper housing 11 and the rotating disk 14 and the gap between the fixed disk 13 and the rotating disk 14 to their original states). This ensures that the gap between the upper housing 11 and the rotating disk 14 and the gap between the fixed disk 13 and the rotating disk 14 are reliably returned to their original states after switching the flow path. This ensures the sealing performance of the upper seal member 17 and the lower seal member 18.

[0216] In this embodiment, as shown in Figures 75(A) to 75(D) and 78(A) to 78(D), when the rotating disk 14 rotates, the rotating shaft 15 lifts down (returning the fixed disk 13 and the upper housing 11 to their original spacing). Therefore, when the flow path is switched, the surface pressure applied to the seal members 17, 18 between the fixed disk 13 and the upper housing 11 is reduced, and it can be seen that the seal members 17, 18 can be prevented from coming off due to sliding wear or getting caught. In addition, in this embodiment, unlike the previous embodiments, as shown in Figures 70(A) to 70(D), the rotating disk 14 rotates while the rotating shaft 15 remains lifted up (while widening the spacing between the fixed disk 13 and the upper housing 11). Therefore, when the flow path is switched, it is possible to more reliably prevent the seal members 17, 18 from coming off due to sliding wear or getting caught.

[0217] In this embodiment, in a "double-side idling type" configuration in which the flow path can be switched between three patterns, the "idling angle" of the rotating shaft 15 and the "switching angle" of the flow path are set to the same value of "30°." Therefore, as shown in Figures 70(A) to 70(D), 75(A) to 75(D), and 78(A) to 78(D), when switching the flow path, the rotating shaft 15 is lifted up, and then the flow path is switched and the rotating shaft 15 is lifted up or lifted down simultaneously. This allows the drive torque of the rotating shaft 15 (drive torque of the drive unit 4) to be reduced, and the drive unit 4 (motor) can be made smaller.

[0218] Seventh Embodiment Next, the seventh embodiment will be described in detail with reference to FIGS. 84(A) to 90(C).

[0219] [Switching flow path patterns] The flow path switching device 8 of this embodiment differs from that of the sixth embodiment in the switching pattern of the fluid flow path. That is, in this embodiment, the fluid flow path can be switched between two patterns in the same "double-side idle type" as in the sixth embodiment. Figures 84(A) to 90(C) show operational diagrams related to switching of the flow path pattern.

[0220] First, Figures 84(A) to 84(C) show the "initial state" of the flow path switching device 8 of this embodiment, and Figure 84(A) is an image diagram showing the engagement relationship between the through-hole 14a of the rotary disc 14 and the rotary shaft 15. Each of Figures 85 to 90 (described later) (A) is an image diagram equivalent to Figure 84(A). Figure 84(B) is an image diagram showing the change in lift of the rotary shaft 15 with respect to the rotary shaft angle. Each of Figures 85 to 90 (described later) (B) is an image diagram equivalent to Figure 84(B). Figure 84(C) is a plan view equivalent to Figure 62 showing the rotational positions of the rotary disc 14 and the rotation communicating passage 40. Each of Figures 85 to 90 (described later) (C) is a plan view equivalent to Figure 84(C).

[0221] In this "initial state," as shown in FIG. 84(A), the rotating shaft 15 is positioned in a state in which there are gaps 28 on both sides of the through-hole 14a in the rotational direction, and the shaft protrusion 15b rides down on the disk recess 13e, thereby lifting down the rotating shaft 15 as shown in FIG. 84(B). The rotating disk 14 and the rotation communicating passage 40 are disposed in the state shown in FIG. 84(C). At this time, the first rotation communicating passage 41 communicates with the first inflow passage 21 and the first fixed communicating passage 51, the second rotation communicating passage 42 communicates with the second inflow passage 22 and the second fixed communicating passage 52, the third rotation communicating passage 43 communicates with the third inflow passage 23 and the third fixed communicating passage 53, and the fourth rotation communicating passage 44 communicates with the fourth inflow passage 24 and the fourth fixed communicating passage 54. The disk rotation angle at this time is defined as "0°," and this passage switching state is defined as "pattern A."

[0222] Next, we will explain the changes from the "initial state" one by one. Figures 85(A) to 85(C) show a "30° rotated state" in which the rotating shaft 15 has rotated "30°" clockwise from the "initial state." In this state, as shown in Figure 85(A), the rotating shaft 15 rotates idly clockwise "30°" from the "initial state" and engages with the other inner wall of the through-hole 14a, and the shaft protrusion 15b rides up on one side edge of the top 13h of the disk protrusion 13g, thereby lifting up the rotating shaft 15 as shown in Figure 85(B). Also, as shown in Figure 85(C), the disk rotation angle remains "0°," and the flow path switching state of the rotation communicating passage 40 is "pattern A," the same as in the "initial state."

[0223] Next, Figures 86(A) to 86(C) show a "60° rotated state" in which the rotating shaft 15 has rotated "30°" clockwise from the "30° rotated state." In this state, as shown in Figure 85(A), the rotating shaft 15 rotates "30°" clockwise together with the rotating disc 14, and the shaft protrusion 15b rides on the other side edge of the top 13h of the disc protrusion 13g, so that the rotating shaft 15 rotates clockwise while remaining lifted up, as shown in Figure 86(B). Also, as shown in Figure 86(C), the rotation communicating passage 40 rotates "30°" clockwise. In this "30° rotation state," the first rotation communicating passage 41 communicates with the second inflow passage 22 and the first fixed communicating passage 51, the second rotation communicating passage 42 communicates with the third inflow passage 23 and the second fixed communicating passage 52, the third rotation communicating passage 43 communicates with the fourth inflow passage 24 and the third fixed communicating passage 53, and the fourth rotation communicating passage 44 communicates with the first inflow passage 21 and the fourth fixed communicating passage 54. The disc rotation angle at this time is "30°," and this passage switching state is defined as "Pattern B."

[0224] As described above, in this embodiment, the "switching angle" by which the rotary disk 14 is rotated to switch the flow paths of the flow path switching device 8 is set to "30°." That is, in this embodiment, the "idle rotation angle" of the rotating shaft 15 in the clockwise direction and the "switching angle" of the rotary disk 14 for switching the flow paths are set to the same value of "30°."

[0225] Next, Figures 87(A) to 87(C) show a "30° return rotation state" in which the rotating shaft 15 has rotated counterclockwise by 30° from the "60° rotation state." In this state, as shown in Figure 87(A), the rotating shaft 15 idles counterclockwise by 30°, and the shaft protrusion 15b rides on one side edge of the apex 13h of the disk protrusion 13g, causing the rotating shaft 15 to rotate counterclockwise while remaining lifted up, as shown in Figure 87(B). Also, as shown in Figure 87(C), the rotation communicating passage 40 remains in the same position as in the "60° rotation state," and the disk rotation angle remains at 30°. The flow path switching state at this time is "Pattern B," the same as in the "60° rotation state."

[0226] Next, Figures 88(A) to 88(C) show a "0° return rotation state" in which the rotating shaft 15 has rotated counterclockwise by a further "30°" from the "30° return rotation state." In this state, as shown in Figure 88(A), the rotating shaft 15 idles counterclockwise by "30°" and engages with one inner wall of the through-hole 14a, and the shaft protrusion 15b rides down into the disk recess 13e, thereby lifting the rotating shaft 15 down as shown in Figure 88(B). Also, as shown in Figure 88(C), the rotation communicating passage 40 remains in the same position as in the "30° return rotation state," and the disk rotation angle remains at "30°." The flow path switching state at this time is "Pattern B," the same as the "30° return rotation state."

[0227] Next, Figures 89(A) to 89(C) show a "-30° rotation state" in which the rotating shaft 15 has rotated "30°" counterclockwise from the "return 0° rotation state." In this state, as shown in Figure 89(A), the rotating shaft 15 rotates "30°" counterclockwise together with the rotating disc 14, and the shaft protrusion 15b rides up on the disc protrusion 13g, thereby lifting up the rotating shaft 15 as shown in Figure 89(B). Also, as shown in Figure 89(C), the rotating disc 14 and the rotation communicating passage 40 have rotated "30°" counterclockwise. The flow path switching state at this time is "pattern A," the same as the "initial state."

[0228] 90(A) to 90(C) show a "return initial state" in which the rotating shaft 15 has rotated "30°" clockwise from the "-30° rotation state." In this state, as shown in FIG. 90(A), the rotating shaft 15 idles "30°" clockwise, and the shaft protrusion 15b rides down on the disc recess 13e, causing the rotating shaft 15 to lift down as shown in FIG. 90(B). Also, as shown in FIG. 90(C), the rotation communicating passage 40 has returned to the same position as in the "initial state," and the disc rotation angle is "0°." The flow path switching state at this time is "pattern A."

[0229] [About the function and effect of the flow path switching device] The configuration of the flow path switching device 8 of this embodiment described above is a "double-sided idling type" in which the rotating shaft 15 can idly rotate in both directions in the rotational direction from the "initial state," and the flow path can be switched between two patterns. Although there are a mode in which the flow path is switched simultaneously with the lift-down of the rotating shaft 15 and a mode in which the flow path is switched while the rotating shaft 15 is lifted up, a mode in which the flow path is switched while the rotating shaft 15 is lifted up can be added. That is, as shown in Figures 86(A) to 86(C), the rotating disc 14 rotates while the rotating shaft 15 is lifted up (while widening the gap between the fixed disc 13 and the upper housing 11). Therefore, it can be seen that the sliding wear and detachment of the seal members 17 and 18 due to snagging can be suppressed when the flow paths are switched.

[0230] Eighth Embodiment Next, the eighth embodiment will be described in detail with reference to FIGS. 91(A) to 95(C).

[0231] [Regarding engaging and engaged structures] This embodiment is a modification of the third embodiment, and differs from the third embodiment in the configurations of the engaging structure K1 and the engaged structure K2. In this embodiment, as in the third embodiment, the fluid flow path is configured to be switchable between two patterns, and the rotating shaft 15 in the "initial state" is a "one-side free-spin type" that can only spin clockwise.

[0232] 91(A) to 91(C) show the "initial state" of the flow path switching device 1 of this embodiment, and FIG. 91(A) is the same conceptual diagram as FIG. 40(A). Each of (A) of FIGS. 92 to 95, which will be described later, is a conceptual diagram equivalent to FIG. 91(A). FIG. 91(B) is a conceptual diagram showing the relationship between the engaging structure K1 (shaft protrusion 15b and shaft recess 15c) and the engaged structure K2 (disk recess 13e and disk protrusion 13g) of this embodiment. Each of (B) of FIGS. 92 to 95, which will be described later, is a conceptual diagram equivalent to FIG. 91(B). As shown in FIGS. 91(B) to 95(B), in this embodiment, the apex 15e of the shaft protrusion 15b and the apex 13h of the disk protrusion 13g each form a convex curved surface. In this embodiment, the inclination angle of side surface 15d of shaft protrusion 15b is set to be the same as the inclination angles of side surface 13i of disk protrusion 13g and disk recess 13e. Figure 91(C) is the same conceptual diagram as Figure 40(B). Each of Figures 92 to 95 (C), which will be described later, is a conceptual diagram similar to Figure 91(C).

[0233] In the "initial state" shown in Figures 91(A) to 91(C), as shown in Figure 91(A), the rotating shaft 15 is positioned in a state in which there is a gap 28 only in the clockwise direction in the through-hole 14a, and as shown in Figures 91(B) and 91(C), the shaft protrusion 15b rides down on the disc recess 13e, and the rotating shaft 15 is lifted down. In this state, as shown in Figure 91(B), the shaft protrusion 15b fits into and engages with the disc recess 13e.

[0234] Next, changes from the "initial state" will be explained one by one. Figures 92(A) to 92(C) show a "45° rotated state" in which the rotating shaft 15 has rotated "45°" clockwise from the "initial state." In this state, as shown in Figure 92(A), the rotating shaft 15 rotates 45° clockwise from the "initial state" and engages with the other inner wall of the through-hole 14a, and as shown in Figures 92(B) and 92(C), the shaft protrusion 15b rides up on the disk protrusion 13g, and the rotating shaft 15 is lifted up. In this state, as shown in Figure 92(B), the top 15e of the shaft protrusion 15b rides up and abuts on the top 13h of the disk protrusion 13g.

[0235] Next, Figures 93(A) to 93(C) show a "90° rotated state" in which the rotating shaft 15 has rotated a further "45°" clockwise from the "45° rotated state." In this state, as shown in Figure 93(A), the rotating shaft 15 has rotated "45°" clockwise together with the rotating disc 14 from the "45° rotated state," and as shown in Figures 93(B) and 93(C), the shaft protrusion 15b rides down into the disc recess 13e, and the rotating shaft 15 is lifted down. In this state, as shown in Figure 93(B), the shaft protrusion 15b fits into and engages with the disc recess 13e.

[0236] Next, Figures 94(A) to 94(C) show a "45° rotated back state" in which the rotating shaft 15 has rotated 45° counterclockwise from the "90° rotated state." In this state, as shown in Figure 94(A), the rotating shaft 15 rotates 45° counterclockwise from the "90° rotated state" and engages with one inner wall of the through-hole 14a, and as shown in Figures 94(B) and 94(C), the shaft protrusion 15b rides up on the disk protrusion 13g, and the rotating shaft 15 is lifted up. In this state, as shown in Figure 94(B), the top 15e of the shaft protrusion 15b rides up and abuts on the top 13h of the disk protrusion 13g.

[0237] Next, Figures 95(A) to 95(C) show a "return initial state" in which the rotating shaft 15 has rotated counterclockwise by "45°" from the "45° return rotated state." In this state, as shown in Figure 95(A), the rotating shaft 15 has rotated counterclockwise by "45°" together with the rotating disc 14 from the "45° return rotated state," and as shown in Figures 95(B) and 95(C), the shaft protrusion 15b rides down on the disc recess 13e, and the rotating shaft 15 is lifted down. In this state, as shown in Figure 95(B), the shaft protrusion 15b fits into and engages with the disc recess 13e.

[0238] [About the function and effect of the flow path switching device] According to the configuration of the flow path switching device 1 of this embodiment described above, the top 15e of the shaft convex portion 15b and the top 13h of the disk convex portion 13g each form a convex curved surface, so that when the rotating shaft 15 is lifted up and the top 15e of the shaft convex portion 15b rides on the top 13h of the disk convex portion 13g, as shown in Figures 92(B) and 94(B), they engage stably, thereby preventing sudden changes in the rise and fall of the shaft convex portion 15b.

[0239] Ninth Embodiment Next, the ninth embodiment will be described in detail with reference to FIGS.

[0240] [Regarding engaging and engaged structures] This embodiment is a modification of the eighth embodiment, and differs from the eighth embodiment in the configurations of the engaging structure K1 and the engaged structure K2.

[0241] 96 to 98 relate to the flow path switching device 1 of this embodiment. FIG. 96 is a conceptual diagram showing the relationship between the engaging structure and the engaged structure when the rotating shaft 15 is lifted down before flow path switching. FIG. 97 is a conceptual diagram showing the relationship between the engaging structure and the engaged structure when the rotating shaft 15 is being lifted up during flow path switching. FIG. 98 is a conceptual diagram showing the relationship between the engaging structure and the engaged structure when the rotating shaft 15 is lifted up during flow path switching. As shown in FIGS. 96 to 98, in this embodiment, the apex 15e of the shaft protrusion 15b and the apex 13h of the disk protrusion 13g each form a convex curved surface, and the bottom of the disk recess 13e forms a concave curved surface. In this embodiment, the radius of the convex curved surface of the apex 15e of the shaft protrusion 15b is smaller than the radius of the concave curved surface of the bottom of the disk recess 13e.

[0242] In contrast, Figures 99 to 101 relate to a comparative example (eighth embodiment), where Figure 99 is an image diagram showing the relationship between the engaging structure and the engaged structure when the rotating shaft 15 is lifted down before switching the flow path, Figure 100 is an image diagram showing the relationship between the engaging structure and the engaged structure when the rotating shaft 15 is lifted up during switching the flow path, and Figure 101 is an image diagram showing the relationship between the engaging structure and the engaged structure when the rotating shaft 15 is lifted up during switching the flow path.

[0243] [About the function and effect of the flow path switching device] According to the configuration of the flow path switching device 1 of this embodiment described above, as shown in FIGS. 96 to 98, the radius of the convex curved surface of the shaft protrusion 15b is smaller than the radius of the concave curved surface of the disk recess 13e. Therefore, when the rotating shaft 15 starts to lift up from the state shown in FIG. 96, that is, at the beginning of flow path switching when the rotating shaft 15 starts to rotate to switch the flow path, the sliding resistance of the shaft protrusion 15b against the disk recess 13e is smaller than that of the comparative example shown in FIG. 99. Comparing the case shown in FIG. 97 with the case shown in FIG. 100, the sliding resistance in both cases is approximately the same. Furthermore, comparing the case shown in FIG. 98 with the case shown in FIG. 101, the sliding resistance in both cases is also approximately the same. Therefore, the driving torque of the rotating shaft 15 can be reduced at the beginning of flow path switching, and the lift angle when the rotating shaft 15 starts to lift up can be reduced. Furthermore, since the lift angle when the rotating shaft 15 starts to lift up can be reduced, the driving torque of the rotating shaft 15 can be suppressed.

[0244] Figure 102 is a graph showing the relationship between changes in rotation shaft angle and changes in drive torque. In Figure 102, the thick line BL represents this embodiment, and the dashed line DL represents the comparative example (eighth embodiment). As Figure 102 shows, in this embodiment, the drive torque when the rotation shaft angle is "0°" is lower than that of the comparative example, and the drive torque when the rotation shaft angle is "45°" is higher than that of the comparative example.

[0245] Tenth Embodiment Next, the tenth embodiment will be described in detail with reference to FIGS.

[0246] [Regarding the problem of the ninth embodiment] In the ninth embodiment, the top 15e of the shaft protrusion 15b and the top 13h of the disk protrusion 13g each have a convex curved surface, and the bottom of the disk recess 13e has a concave curved surface. Furthermore, the radius of the convex curved surface of the top 15e of the shaft protrusion 15b is smaller than the radius of the concave curved surface of the bottom of the disk recess 13e. Therefore, when the rotating shaft 15 is lifted down and the shaft protrusion 15b rests on the disk recess 13e, the top 15e of the shaft protrusion 15b and the bottom of the disk recess 13e come into contact at a single point. In this state, the contact pressure of each seal member 17, 18 with the upper housing 11 and the fixed disk 13 is maximized, resulting in high stress acting on the contact point between the top 15e of the shaft protrusion 15b and the bottom of the disk recess 13e.

[0247] Therefore, when the rotating shaft 15 starts to rotate to lift up from the lift-down state, the top 15e of the shaft protrusion 15b and the bottom of the disk recess 13e begin to slide against each other at a single point, increasing sliding resistance and potentially accelerating wear between the two. As wear at the top of the shaft protrusion 15b or the bottom of the disk recess 13e progresses, the gap between the rotating disk 14 and the fixed disk 13 narrows, further increasing the contact pressure of the seal members 17 and 18 and further increasing sliding resistance. As a result, the driving torque required to lift up the rotating shaft 15 increases, requiring the driver 4 to have a high output. Therefore, in this embodiment, the shapes of the engaging structure and the engaged structure (the shaft protrusion 15b and the disk recess 13e) are improved as follows to reduce the driving torque required to lift up the rotating shaft 15 from the lift-down state.

[0248] [Regarding engaging and engaged structures] Figures 103 to 113 show, in conceptual diagrams, the change in the relationship between the engaging structure and the engaged structure when the rotating shaft 15 is lifted up from a lift-down state and then further lifted down during flow path switching in the flow path switching device 1 of this embodiment.

[0249] Figure 103 shows the relationship between the engaging structure and the engaged structure in a lift-down state before flow path switching, and Figure 104 shows an enlarged view of the ground contact portion of Figure 103. As shown in Figures 103 and 104, the disk recess 13e in this embodiment has a V-shaped gently inclined concave surface (gentle concave inclined surface) 13ea at its bottom, and a steeply inclined surface 13ia that continues from the gently inclined concave surface 13ea to the disk protrusion 13g and forms the side surface 13i of the disk protrusion 13g. In this embodiment, the top 13h of the disk protrusion 13g forms a convex curved surface. In addition, the shaft protrusion 15b has, at its top 15e, a V-shaped gently convex inclined surface (convex gently inclined surface) 15ea that aligns with the concave gently inclined surface 13ea and can come into surface contact with it, and the side surface 15d of the shaft protrusion 15b that continues from the convex gently inclined surface 15ea has a steeply inclined surface 15da that aligns with the steeply inclined surface 13ia of the side surface 13i of the disk protrusion 13g and can come into surface contact with it.

[0250] In the state before this flow path switching, the contact surface pressure of each sealing member 17, 18 against the upper housing 11 and fixed disk 13 becomes high, and the ground contact surface pressure between the shaft convex portion 15b and the disk concave portion 13e becomes high, but since the concave gently inclined surface 13ea and the convex gently inclined surface 15ea are in contact with each other, the stress of the high ground contact surface pressure is dispersed rather than being concentrated at one point.

[0251] Next, Figure 105 shows the relationship between the engaging structure and the engaged structure at the start of flow path switching (during initial drive when lift-up begins). During this initial drive, the convex gently inclined surface 15ea contacts the concave gently inclined surface 13ea, and the steeply inclined surface 15da of the shaft convex portion 15b contacts the steeply inclined surface 13ia of the disk convex portion 13g, and they slide together. At this time, each seal member 17, 18 is subjected to high contact pressure, and the contact pressure between the shaft convex portion 15b and the disk concave portion 13e becomes high. However, since the concave gently inclined surface 13ea and the convex gently inclined surface 15ea are in contact with each other, and the steeply inclined surface 13ia and the steeply inclined surface 15da are in contact with each other, the stress of the high contact pressure is dispersed.

[0252] Next, Figure 106 shows the relationship between the engaging structure and the engaged structure during flow path switching (during lift-up). During this lift-up, steeply inclined surface 15da of shaft protrusion 15b slides against steeply inclined surface 13ia of disk recess 13e while in contact with it. At this time, rotating shaft 15 begins to lift up (fixed disk 13 begins to descend), and the gap between upper housing 11 and fixed disk 13 relative to rotating disk 14 increases, so the contact surface pressure of each seal member 17, 18 decreases to a moderate surface pressure.

[0253] Next, Figure 107 shows the relationship between the engaging structure and the engaged structure during the same flow path switching (during lift-up). During this lift-up, the gently sloping convex surface 15ea of ​​the shaft protrusion 15b slides against the convex curved apex 13h of the disk protrusion 13g while in contact with it. Figure 108 shows an enlarged view of the contact area in Figure 107. At this time, the rotating shaft 15 lifts up (the fixed disk 13 descends), further increasing the gap between the upper housing 11 and the fixed disk 13 relative to the rotating disk 14. This further reduces the contact pressure of the seal members 17 and 18, resulting in a low contact pressure. This reduces the load on the apex 13h of the disk protrusion 13g, and although the contact stress of the shaft protrusion 15b against the apex 13h of the disk protrusion 13g is concentrated, the stress is reduced.

[0254] Next, Figure 109 shows the relationship between the engaging structure and the engaged structure during flow path switching, immediately after the apex 15e of the shaft protrusion 15b passes over the apex 13h of the disk protrusion 13g (when the lift-down begins). Figure 110 shows an enlarged view of the contact portion of Figure 109. At the beginning of this lift-down, as in Figures 107 and 108, the gently sloping convex surface 15ea of ​​the shaft protrusion 15b slides against the curved surface of the apex 13h of the disk protrusion 13g while in contact with the shaft. At this time, the rotating shaft 15 begins to lift down (the fixed disk 13 begins to rise). However, because the gap between the upper housing 11 and the fixed disk 13 relative to the rotating disk 14 is widening, the contact surface pressure of each seal member 17, 18 is reduced to a low surface pressure. Therefore, as in Figures 107 and 108, although the contact stress of the shaft protrusion 15b against the apex 13h of the disk protrusion 13g is concentrated, the stress is reduced.

[0255] Next, Figure 111 shows the relationship between the engaging structure and the engaged structure during flow path switching (during lift-down). During this lift-down, steeply inclined surface 15da of shaft protrusion 15b slides against steeply inclined surface 13ia of disk recess 13e while in contact with it. At this time, rotating shaft 15 is in the middle of lift-down (while fixed disk 13 is rising), and the gap between upper housing 11 and fixed disk 13 relative to rotating disk 14 is decreasing, so the contact surface pressure of each seal member 17, 18 begins to increase and becomes moderate.

[0256] Next, Figure 112 shows the relationship between the engaging structure and the engaged structure before the flow path switching is completed (before the lift-down is completed). Before the lift-down is completed, the convex gently inclined surface 15ea contacts the concave gently inclined surface 13ea, and the steeply inclined surface 15da of the shaft convex portion 15b contacts the steeply inclined surface 13ia of the disk convex portion 13g, and they slide together. At this time, each seal member 17, 18 is subjected to high contact pressure, and the contact pressure between the shaft convex portion 15b and the disk concave portion 13e becomes high. However, the concave gently inclined surface 13ea and the convex gently inclined surface 15ea come into contact with each other, and the steeply inclined surface 13ia and the steeply inclined surface 15da come into contact with each other, so the stress of the high contact pressure is dispersed.

[0257] Next, Figure 113 shows the relationship between the engaging structure and the engaged structure when the flow path switching is completed (lift-down completion phase). When the lift-down is completed, the surface pressure of each seal member 17, 18 becomes higher, and the contact surface pressure between the shaft protrusion 15b and the disc recess 13e becomes higher. However, since the recessed gently inclined surface 13ea and the convex gently inclined surface 15ea come into contact with each other, the stress of the high contact surface pressure is dispersed.

[0258] [About the function and effect of the flow path switching device] According to the configuration of the flow path switching device 1 of this embodiment described above, when the rotating shaft 15 is lifted down before flow path switching, the shaft protrusion 15b of the rotating shaft 15 engages with the disk recess 13e of the fixed disk 13, and the convex gently inclined surface 15ea of ​​the shaft protrusion 15b comes into contact with the concave gently inclined surface 13ea of ​​the disk recess 13e. When the rotating shaft 15 starts to rotate from this state to switch the flow path, the shaft protrusion 15b begins to slide gently against the disk recess 13e due to the contact between the concave gently inclined surface 13ea and the convex gently inclined surface 15ea, and then slides due to the contact surface between the convex gently inclined surface 15ea and the concave gently inclined surface 13ea. Furthermore, as the rotation of the rotating shaft 15 progresses, the contact surface between the disk recess 13e and the shaft protrusion 15b transitions from the contact surface between the concave gently inclined surface 13ea and the convex gently inclined surface 15ea to the contact surface between the steep inclined surfaces 13ia and 15da, and the shaft protrusion 15b slides due to the contact surface. Therefore, when the rotating shaft 15 starts to rotate from a state in which the shaft protrusion 15b is engaged with the disk recess 13e, the drive torque required to rotate the rotating shaft 15 can be reduced, and wear on the shaft protrusion 15b and the disk recess 13e can be suppressed. Furthermore, the reduction in drive torque allows the drive unit 4 to be made smaller.

[0259] Eleventh Embodiment Next, the eleventh embodiment will be described in detail with reference to FIGS.

[0260] [Regarding engaging and engaged structures] This embodiment is a modification of the tenth embodiment, and differs from the tenth embodiment in the configuration of the engaging structure and the engaged structure. Fig. 114 shows the relationship between the engaging structure and the engaged structure in the flow path switching device 1 of this embodiment during flow path switching (during lift-up of the rotating shaft 15) in an image diagram similar to Fig. 107. Fig. 115 shows an enlarged image diagram of the ground contact portion in Fig. 114.

[0261] As shown in Figures 114 and 115, the top 13h of the disk protrusion 13g in this embodiment is not a convex curved surface, but rather a V-shaped convex gently inclined surface 13ha, similar to the top 15e of the shaft protrusion 15b. Therefore, during this lift-up, the convex gently inclined surface 15ea of ​​the shaft protrusion 15b slides against the convex gently inclined surface 13ha of the top 13h of the disk protrusion 13g in a contacting state. Therefore, compared to the tenth embodiment, the contact stress between the shaft protrusion 15b and the disk protrusion 13g can be alleviated, and wear of both 15b and 13g can be suppressed.

[0262] <Another embodiment> The disclosed technology is not limited to the above-described embodiments, and can be implemented by appropriately modifying part of the configuration within the scope of the disclosed technology.

[0263] (1) In the first embodiment, the flow path switching device 1 is configured as an eight-way valve, but it is not limited to this and can also be configured as other multi-way valves such as a three-way valve, a four-way valve, a six-way valve, etc. Therefore, it is sufficient that the rotary disc 14 has at least one rotary communicating passage 40, and it is sufficient that the fixed disc 13 has multiple fixed communicating passages 50.

[0264] (2) The "sliding resistance reducing structure" in the first embodiment is an example, and is not limited to the engaging structure K1 and the engaged structure K2 described above.

[0265] (3) In the second embodiment, only the top 15e of the shaft convex portion 15b is formed into a convex curved surface, but only the top 13h of the disk convex portion 13g can be formed into a convex curved surface, or both the top 15e of the shaft convex portion 15b and the top 13h of the disk convex portion 13g can be formed into a convex curved surface.

[0266] (4) In the second embodiment, the top 15e of the shaft protrusion 15b is formed in a convex curved surface, but this top can also be formed in a flat surface. [Industrial Applicability]

[0267] The disclosed technology can be used, for example, to switch the flow path of a fluid in a fluid circuit through which a fluid such as a refrigerant flows. [Explanation of symbols]

[0268] 1 Flow path switching device 2. Housing 3 Valve body 4. Drive unit (drive means) 5 Control section (control means) 8 Flow path switching device 13 Fixed Disk 13e Disc recess 13ea concave gentle slope 13g Disc protrusion 13h top 13ha Convex gentle slope 13i side part 13ia steep slope 14 Rotating disk (drive disk) 15 Rotation axis 15a Tip 15b Shaft protrusion 15c Shaft recess 15d Side part 15da steep slope 15e Top 15ea convex gentle slope 17 Upper seal member 18 Lower seal member 20 Inlet flow path (communicating passage) 28 Gap 30 Outlet flow path (communicating passage) 40 Rotating passage (passage) 50 Fixed communication path (communication path) X-axis direction

Claims

1. Housing and a valve body portion disposed inside the housing; Equipped with the valve body portion includes a fixed disk, a drive disk stacked on the fixed disk and rotating relative to the fixed disk, and a rotation shaft for rotating the drive disk, the housing, the fixed disk, and the drive disk each have a plurality of communication passages, and the communication passages are connected as the drive disk rotates to form a fluid flow path; A seal member is provided in the flow path to prevent leakage of the fluid at least between the fixed disk and the drive disk. In the flow path switching device, a tip end of the rotary shaft is provided so as to be able to come into contact with and engage with the fixed disk, The fixed disk is configured to be reciprocally movable in the axial direction by the tip of the rotary shaft coming into contact with and engaging with the rotary shaft as it rotates. A flow path switching device characterized by:

2. The flow path switching device according to claim 1, the tip end of the rotating shaft includes a shaft protrusion and a shaft recess that are arranged in a circumferential direction, the fixed disk includes a disk recess and a disk protrusion that can come into contact with and engage with the shaft protrusion and the shaft recess, The shaft protrusions, the shaft recesses, the disk recesses, and the disk protrusions each include a side surface that is inclined in the circumferential direction. A flow path switching device characterized by:

3. The flow path switching device according to claim 2, The top of at least one of the shaft protrusion and the disk protrusion is formed as a flat surface or a convex curved surface, and the bottom of at least one of the disk recess and the shaft recess is formed as a flat surface or a concave curved surface. A flow path switching device characterized by:

4. The flow path switching device according to claim 2, the disk recess has a V-shaped gently inclined concave surface at its bottom, and a steeply inclined surface that continues from the gently inclined concave surface to the disk protrusion and forms the side surface of the disk protrusion, The shaft protrusion has a convex gently inclined surface at its top that matches the concave gently inclined surface and forms a V shape, and the side surface of the shaft protrusion that continues from the convex gently inclined surface has a steeply inclined surface that matches the steeply inclined surface of the side surface of the disk protrusion. A flow path switching device characterized by:

5. 5. The flow path switching device according to claim 1, The flow path switching device is characterized in that the drive disk and the rotary shaft are connected to each other so as to be relatively movable in the rotational direction and the axial direction.

6. The flow path switching device according to claim 5, The connection between the rotating shaft and the drive disk has a gap in the rotation direction. A flow path switching device characterized by:

7. The flow path switching device according to claim 6, An idle rotation angle at which the rotary shaft idles in the gap when the tip end of the rotary shaft transitions from the state in which it engages with the fixed disk to the state in which it abuts on the fixed disk is set to the same angle as a switching angle at which the drive disk rotates to switch the flow path. A flow path switching device characterized by:

8. The flow path switching device according to claim 7, a driving means for driving the rotation shaft; control means for controlling the driving means; Further provided with The control means controls the drive means to rotate the rotary shaft, switch the flow path with the tip end of the rotary shaft in contact with the fixed disk, and then rotate the rotary shaft in the reverse direction, stopping the rotation of the rotary shaft with the tip end of the rotary shaft engaged with the fixed disk. A flow path switching device characterized by:

Images