Valve device

Abstract

This valve device comprises: a housing (10); a drive unit (40); a shaft (50); a stationary disk (20) in which a flow passage hole (23) and a stationary disk hole (24) are formed; and a drive disk (30). The shaft has an insertion portion (51) at one end in the axial direction. The insertion portion has a shaft tapered surface (512) that forms a shaft tapered portion (511). The drive disk has, on one side in the shaft insertion direction, a sliding surface (31) that slides relative to the stationary disk. The stationary disk has, on the other side in the shaft insertion direction, a seal surface (21) that faces the sliding surface. The stationary disk hole has a stationary inlet portion (241) on the seal surface, and a stationary inlet tapered surface (243) that forms a stationary inlet tapered portion (242). In the stationary inlet tapered portion, an angle formed by a surface along the stationary inlet tapered surface and a virtual surface (VS) parallel to the shaft insertion direction is larger than an angle formed by a surface along the shaft tapered surface and the virtual surface.

Description

Valve equipment CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Patent Application No. 2024-49904, filed on March 26, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a valve device.

[0003] A conventional valve device includes a housing that defines a fluid passage, a fixed disk that defines a fluid passage hole through which the fluid passes, a drive disk that adjusts the opening of the passage hole, and a drive unit that outputs a torque to rotate the drive disk. This valve device also includes a shaft that transmits the torque output by the drive unit to the drive disk, and the shaft is disposed within the housing and passes through insertion holes formed in the drive disk and the fixed disk (see, for example, Patent Document 1).

[0004] In this valve device, one inlet that introduces fluid into the fluid passage and two outlets that communicate with the passage holes and allow the fluid to flow out of the fluid passage are formed in the housing. The valve device switches between opening and closing the passage holes in the fixed disk depending on the rotational position of the drive disk that rotates due to the rotational force of the drive unit, thereby switching which of the two outlets communicates with the inlet.

[0005] The valve device also includes a compression spring for rotating the drive disk while pressing it against the fixed disk to prevent fluid from leaking from between the fixed disk and the drive disk when the drive disk is rotated by the rotational force of the drive unit. As a result, when the drive disk rotates, the sliding surface of the drive disk facing the fixed disk slides against the seal surface facing the sliding surface of the fixed disk.

[0006] Japanese Patent Application Laid-Open No. 2022-166527

[0007] However, when the shaft is inserted into the insertion hole of the fixed disk, the tip of the shaft may come into contact with the sealing surface of the fixed disk, causing the sealing surface to bulge. After detailed investigation, the inventors have found that if the sealing surface bulges, the sliding surface will be damaged by the bulged portion of the sealing surface when the sliding surface and the sealing surface slide and rotate, causing fluid to leak from between the fixed disk and the drive disk.

[0008] An object of the present disclosure is to provide a valve device that can suppress leakage of fluid from between a fixed disk and a drive disk due to damage to the sliding surfaces.

[0009] According to one aspect of the present disclosure, there is provided a valve device comprising: a housing forming a fluid passage therein for circulating a fluid; a drive unit that outputs a rotational force; a shaft that rotates about a shaft axis by the rotational force; a fixed disk that is disposed inside the housing and has a flow passage hole through which the fluid flows and a fixed disk hole through which the shaft is inserted; and a drive disk that increases or decreases the opening of the flow passage hole as the shaft rotates and slides on the fixed disk to rotate about the shaft axis, wherein the shaft has an insertion portion that is inserted into the fixed disk hole at one end on one side in the axial direction that is a direction along the shaft axis, and the insertion portion has a shaft tapered surface that forms a shaft tapered portion whose outer diameter gradually decreases along the shaft insertion direction when the direction in which the shaft is inserted into the fixed disk hole is defined as the shaft insertion direction; the drive disk has a sliding surface that slides on the fixed disk on one side in the shaft insertion direction, and the fixed disk has a seal surface that faces the sliding surface on the other side in the shaft insertion direction, The fixed disk hole has a fixed inlet portion into which the shaft is inserted on the sealing surface, and also has a fixed inlet tapered surface that forms a fixed inlet tapered portion whose inner diameter gradually decreases from the fixed inlet portion along the shaft insertion direction, and the angle formed by the surface of the fixed inlet tapered surface and an imaginary plane parallel to the shaft insertion direction of the fixed inlet tapered portion is larger than the angle formed by the surface of the shaft tapered surface and the imaginary plane.

[0010] This makes it difficult for the tip of the insertion part to collide with the seal surface during insertion, even if the axis of the insertion part and the axis of the fixed disk hole are misaligned, thereby suppressing bulging of the seal surface caused by the tip of the insertion part colliding with the seal surface.

[0011] Furthermore, even if the axis of the insertion portion is misaligned with the axis of the fixed disk hole when the shaft is inserted, the tapered surface of the shaft is less likely to slide against the fixed inlet portion, which prevents the seal surface from swelling due to the tapered surface of the shaft sliding against the fixed inlet portion.

[0012] Therefore, damage to the sliding surface caused by the seal surface swelling when the drive disk rotates can be suppressed, and leakage of fluid from between the fixed disk and the drive disk due to damage to the sliding surface can be suppressed.

[0013] FIG. 1 is an external perspective view of a valve device according to the present embodiment; FIG. 2 is a cross-sectional view of the valve device according to the present embodiment; FIG. 3 is a diagram illustrating a state in which a shaft according to the present embodiment is inserted into a drive disk hole and a fixed disk hole; FIG. 4 is a diagram for explaining a drive inlet angle and a drive outlet angle of a drive disk according to the present disclosure; FIG. 5 is a diagram for explaining a fixed inlet angle and a fixed outlet angle of a fixed disk according to the present disclosure; FIG. 6 is a diagram for explaining a fixed inlet angle and a fixed outlet angle of a comparative fixed disk; FIG. 7 is a diagram illustrating a state in which a shaft portion is inserted into a fixed disk hole of a comparative fixed disk; and FIG. 8 is a diagram illustrating a state in which a shaft portion is inserted into a fixed disk hole of a fixed disk according to the present disclosure.

[0014] An embodiment of the present disclosure will be described with reference to FIGS. 1 to 8 . A valve device 1 according to this embodiment is applied to a fluid circulation system in which a fluid (in this example, coolant) circulates to regulate the temperature of the cabin and battery of an electric or hybrid vehicle, for example. The fluid circulation system circulates coolant through a power source for driving the vehicle, a radiator, a heater core for cabin air conditioning, and a battery. For example, LLC (Long Life Coolant) containing ethylene glycol is used as the coolant. The valve device 1 switches the flow path or adjusts the flow rate of the coolant flowing through the fluid circulation system. In this embodiment, the valve device 1 is configured as a five-way valve.

[0015] 1 and 2 , the valve device 1 has a housing 10 that forms a fluid passage F through which a fluid flows. The housing 10 has two inlet ports that allow the fluid to flow into the fluid passage F from outside the valve device 1, and three outlet ports that allow the fluid that has flowed into the fluid passage F to flow out to the outside of the valve device 1. Hereinafter, as shown in FIG. 1 and other figures, the two fluid ports that allow the fluid to flow into the fluid passage F will be referred to as a first inlet portion 11 and a second inlet portion 12, and the three outlet ports that allow the fluid to flow out of the fluid passage F will be referred to as a first outlet portion 13, a second outlet portion 14, and a third outlet portion 15.

[0016] First, the configuration of the valve device 1 of this embodiment will be described. As shown in Figures 1 and 2, the valve device 1 of this embodiment includes a fixed disc 20, a drive disc 30, a drive unit 40, a shaft 50, a lever 60, a torsion spring 70, a compression spring 80, and the like. The valve device 1 accommodates the fixed disc 20, the drive disc 30, the shaft 50, the lever 60, the torsion spring 70, and the compression spring 80 within a housing 10. The valve device 1 also includes a drive unit 40 disposed outside the housing 10. The valve device 1 of this embodiment is configured as a disc valve in which the drive unit 40 rotates the drive disc 30 integrally with the shaft 50 to switch the flow path of cooling water flowing through a fluid circulation system.

[0017] In this embodiment, as shown in Figure 2 and other figures, the direction along the shaft axis CL of the shaft 50 is referred to as the axial direction DRa, the direction to one side of the axial direction DRa is referred to as the downward direction DRa1, and the direction opposite the downward direction DRa1 is referred to as the upward direction DRa2. Furthermore, various configurations will be described using the circumferential direction DRc as the direction around the shaft axis CL and the radial direction DRr as the direction perpendicular to the axial direction DRa and extending radially from the shaft axis CL. The circumferential direction DRc is the direction of rotation of the shaft 50 and the drive disk 30, which are rotated by the rotational force supplied from the drive unit 40. Note that the directions shown in Figure 2 and other figures are merely examples and do not limit the installation state of the valve device 1 of the present disclosure.

[0018] The housing 10 is a non-rotating member. The housing 10 is formed, for example, from a resin material. Specifically, the housing 10 has a main body 16 having a cylindrical shape with a bottom, and a main body cover 17 that closes the open side of the main body 16. In this embodiment, the main body 16 and the main body cover 17 are molded, for example, by injection molding, in which a resin material is poured into a mold and hardened into a desired shape.

[0019] The main body 16 has a bottom wall 160 that forms the bottom surface and a cylindrical side wall 161 that surrounds the shaft axis CL in the circumferential direction DRc. The bottom wall 160 and the side wall 161, together with the main body cover 17, form a fluid passage F. The bottom wall 160 and the side wall 161 are configured as an integrally molded product.

[0020] The main body 16 has a first inlet 11 connected to the outer peripheral surface of the side wall 161. The main body 16 also has a first outlet 13, a second outlet 14, and a third outlet 15 connected to the outer peripheral surface of the bottom wall 160. The main body 16 has a second inlet 12 connected to the lower surface of the bottom wall 160 in the downward direction DRa1.

[0021] The first inlet portion 11 and the first outlet portion 13 are arranged side by side in the axial direction DRa. The first inlet portion 11 is connected to the side wall portion 161 on the upper DRa2 side of the position where the drive disk 30 is housed. On the other hand, the first outlet portion 13 is connected to the bottom wall portion 160 on the lower DRa1 side of the side wall portion 161 that houses the drive disk 30.

[0022] The first outlet portion 13, the second outlet portion 14, and the third outlet portion 15 are arranged side by side at a predetermined interval along the circumferential direction DRc. In this embodiment, the first outlet portion 13, the second outlet portion 14, and the third outlet portion 15 are arranged side by side in this order at intervals of approximately 90°. The second inlet portion 12 is provided in the center of the bottom wall portion 160.

[0023] The first inlet portion 11, the second inlet portion 12, the first outlet portion 13, the second outlet portion 14, and the third outlet portion 15 are configured as tubular members formed so that a fluid can flow through the inside thereof. The first inlet portion 11, the first outlet portion 13, the second outlet portion 14, and the third outlet portion 15 are formed to protrude from the housing 10 along the radial direction DRr. The second inlet portion 12 is formed to protrude from the housing 10 along the axial direction DRa.

[0024] The side wall portion 161 has a cylindrical shape that surrounds in the circumferential direction DRc the passage in the fluid passage F on the upper direction DRa2 side of the fixed disk 20, and extends along the axial direction DRa. The side wall portion 161 is formed so that its axis is coaxial with the shaft axis CL.

[0025] 2, the side wall portion 161 has an inner peripheral side surface portion 1611 on its inner peripheral side that surrounds the outer periphery of the fixed disk 20 and the outer periphery of the drive disk 30. The inner peripheral side surface portion 1611 forms a passage in the fluid passage F on the upper DRa2 side of the fixed disk 20. A fitting groove (not shown) is formed in the inner peripheral side surface portion 1611 and is recessed away from the shaft axis CL. The opening side of the side wall portion 161 is closed by the body cover portion 17.

[0026] The body cover 17 is a lid that closes the opening side of the body 16. The body cover 17 is attached to the body 16 by fitting it inside the body 16 from the opening side of the body 16. The body cover 17 is attached to the body 16 together with the drive unit 40 by, for example, tapping screws S.

[0027] An O-ring 162 that closes the gap between the main body 16 and the main body cover 17 is disposed between the inner peripheral surface of the side wall 161 and the outer peripheral surface of the main body cover 17. The O-ring 162 is made of, for example, urethane rubber, which is an annular elastic body, and is configured to be compressed and elastically deformable when sandwiched between the main body 16 and the main body cover 17.

[0028] The bottom wall portion 160 is a portion on which the fixed disk 20 is installed and which supports the downward direction DRa1 side of the axial center portion 51 (described later) of the shaft 50. The bottom wall portion 160 also forms a fluid passage F that guides the fluid that has flowed in from the first inlet portion 11 and the second inlet portion 12 to the first outlet portion 13, the second outlet portion 14, and the third outlet portion 15.

[0029] 2, the bottom wall portion 160 has a mounting surface 1601 on the upward DRa2 side for placing the fixed disk 20. The bottom wall portion 160 also has a bearing hole 1602 that supports the axial center portion 51 and a passage in the fluid passage F on the downward DRa1 side of the fixed disk 20. The downward DRa1 side of the axial center portion 51 is fitted into the bearing hole 1602. The bearing hole 1602 rotatably supports the axial center portion 51. The passage in the fluid passage F on the downward DRa1 side of the fixed disk 20 is formed by recessing the mounting surface 1601.

[0030] The fluid passage F on the downward DRa1 side of the fixed disk 20 is divided into four sections by the bottom wall 160, and each of the four divided sections communicates with one of the second inlet portion 12, the first outlet portion 13, the second outlet portion 14, and the third outlet portion 15. Although not shown, the bottom wall 160 is provided with a partition that divides the lower fluid passage Fd into a passage communicating with the second inlet portion 12, a passage communicating with the first outlet portion 13, a passage communicating with the second outlet portion 14, and a passage communicating with the third outlet portion 15. In other words, the fluid passage F on the downward DRa1 side of the fixed disk 20 is divided by the partition into four passages communicating with one of the second inlet portion 12, the first outlet portion 13, the second outlet portion 14, and the third outlet portion 15.

[0031] The mounting surface 1601 is formed to extend in a flat plane along the radial direction DRr and the circumferential direction DRc. A groove (not shown) is formed in the mounting surface 1601 for accommodating a gasket 163 that seals the gap between the fixed disk 20 and the mounting surface 1601.

[0032] The gasket 163 is made of, for example, an elastically deformable rubber member, and is formed in a shape corresponding to each of the four passages partitioned into four on the downward direction DRa1 side of the fixed disc 20 in the fluid passage F.

[0033] Fixed disk 20 is a sealing member that seals the gap between bottom wall portion 160 and drive disk 30. As shown in Fig. 2, fixed disk 20 is configured as a substantially disk-shaped member with its thickness direction aligned with axial direction DRa, and its outer diameter is slightly smaller than the inner diameter of side wall portion 161. Fixed disk 20 is also arranged so that its axis is coaxial with shaft axis CL.

[0034] The fixed disk 20 has a seal surface 21 that contacts the drive disk 30 and a support surface 22 that contacts the installation surface 1601. The seal surface 21 is an opposing surface that faces a sliding surface 31 of the drive disk 30, which will be described later, and is in contact with the sliding surface 31. The support surface 22 is a surface of the fixed disk 20 in the downward direction DRa1, and is an opposing surface that faces the installation surface 1601 when the fixed disk 20 is placed in the housing 10.

[0035] The fixed disk 20 is also formed with a plurality of flow path holes 23 that communicate with the four partitioned passages in the fluid passage F located on the downward direction DRa1 side of the fixed disk 20. The fixed disk 20 is configured so that fluid can pass through each of the plurality of flow path holes 23. The fixed disk 20 is also formed with a fixed disk hole 24 at approximately the center, through which the shaft 50 is inserted, and with a fitting protrusion (not shown) on the outer circumferential surface. The fitting protrusion is fitted into a fitting groove (not shown) formed in the inner circumferential side surface portion 1611 of the side wall portion 161, thereby restricting rotation of the fixed disk 20 in the circumferential direction DRc.

[0036] The fixed disk 20 is made of a material that has a smaller coefficient of linear expansion, superior wear resistance, and a smaller coefficient of friction than the constituent material of the housing 10. For example, the fixed disk 20 is made of a high-hardness material that is harder than the housing 10 and the drive disk 30. The fixed disk 20 is made of a metal (for example, SUS, i.e., Steel Use Stainless) that is harder than resin.

[0037] The sealing surface 21 and the support surface 22 are formed to extend in a planar shape along the radial direction DRr and the circumferential direction DRc, and are substantially perpendicular to the axial direction DRa and parallel to each other in the axial direction DRa.

[0038] The plurality of flow path holes 23 are formed at positions spaced apart from the fixed disk hole 24 so as not to overlap with the fixed disk hole 24. The plurality of flow path holes 23 correspond to each of the four passages partitioned into four on the downward direction DRa1 side of the fixed disk 20 in the fluid passage F. The fixed disk hole 24 will be described in detail later.

[0039] The drive disk 30 is a valve element that increases or decreases the opening of the flow path hole 23 by rotating about the shaft axis CL in accordance with the rotation of the shaft 50. As shown in FIG. 2 , the drive disk 30 is configured as a substantially disk-shaped member with its thickness direction aligned with the axis direction DRa, and its outer diameter is smaller than the inner diameter of the side wall portion 161. The drive disk 30 is disposed so that its rotation axis is coaxial with the shaft axis CL and the axis of the fixed disk 20.

[0040] The drive disk 30 has a sliding surface 31 that slides against the seal surface 21 of the fixed disk 20, and an attachment surface 32 to which the lever 60 is attached. The drive disk 30 also has a drive disk hole 33 formed in the approximate center through which the shaft 50 is inserted, one through-hole 34 that passes through the drive disk 30 in the axial direction DRa, and one flow channel 35 that is formed by recessing the slide surface 31. The drive disk hole 33 will be described in detail later.

[0041] The drive disk 30 is made of a material that has a smaller coefficient of linear expansion, superior wear resistance, and a smaller coefficient of friction than the material constituting the housing 10. For example, the drive disk 30 is made of a high-hardness resin that is harder than the housing 10.

[0042] The sliding surface 31 is a surface on the downward direction DRa1 side of the drive disk 30 and faces the seal surface 21. The sliding surface 31 slides against the seal surface 21 of the fixed disk 20 when the drive disk 30 rotates in conjunction with the rotation of the shaft 50. The mounting surface 32 is a surface on the upward direction DRa2 side of the drive disk 30 and faces the lever 60 when the drive disk 30 is disposed in the housing 10.

[0043] The sliding surface 31 and the mounting surface 32 are formed to extend in a planar shape along the radial direction DRr and the circumferential direction DRc, and are substantially perpendicular to the axial direction DRa and parallel to each other in the axial direction DRa.

[0044] The through-holes 34 are formed through the drive disk 30 at positions that can communicate with any one of the plurality of flow path holes 23 of the fixed disk 20, and are formed to allow fluid to pass through. Specifically, the through-holes 34 can communicate with any one of the plurality of flow path holes 23 of the fixed disk 20 that communicates with any one of the first outlet portion 13, the second outlet portion 14, and the third outlet portion 15, depending on the rotational position of the drive disk 30.

[0045] The flow path groove 35 is formed by recessing the sliding surface 31 at a position that can communicate with any one of the plurality of flow path holes 23 of the fixed disk 20. Specifically, the flow path groove 35 is capable of communicating with the second inlet portion 12 among the plurality of flow path holes 23, and also with the flow path hole 23 that communicates with any one of the first outlet portion 13, the second outlet portion 14, and the third outlet portion 15. The flow path groove 35 forms a flow path that communicates the second inlet portion 12 with any one of the first outlet portion 13, the second outlet portion 14, and the third outlet portion 15 depending on the rotational position of the drive disk 30.

[0046] The drive unit 40 is provided on the upper side DRa2 of the main body cover 17. The drive unit 40 is a device for outputting a rotational force for rotating the shaft 50. The drive unit 40 has the shaft 50, a motor (not shown) as a drive source for rotating the shaft 50, and a gear unit (not shown) that transmits the output of the motor to the shaft 50. The motor may be, for example, a servo motor, a stepping motor, or a brushless motor. The gear unit may be, for example, a gear mechanism including a helical gear or a spur gear.

[0047] The shaft 50 is a rotating shaft that rotates about the shaft axis CL by the rotational force output by the drive unit 40. The shaft 50 is rotatably supported on both sides in the axial direction DRa by the housing 10. As a specific example, the downward DRa1 side of the shaft 50 is rotatably supported by a bearing (not shown) provided in the bearing hole 1602, and the upward DRa2 side of the shaft 50 is rotatably supported by the bearing unit 41 provided in the main body cover unit 17. These bearings may be plain bearings, ball bearings, or the like.

[0048] The shaft 50 includes a metal axial center portion 51 and a resin holder portion 52 connected to the axial center portion 51. The axial center portion 51 and the holder portion 52 are connected to each other so as to be rotatable together. The axial center portion 51 and the holder portion 52 are insert-molded products molded integrally by insert molding.

[0049] The axial center portion 51 includes the shaft axis CL of the shaft 50 and extends along the axial direction DRa. The axial center portion 51 is made of a metal rod member to ensure straightness. The upward direction DRa2 side of the axial center portion 51 is connected to the holder portion 52. The axial center portion 51 is inserted through the fixed disk hole 24 of the fixed disk 20 and the drive disk hole 33 of the drive disk 30, penetrating the fixed disk 20 and the drive disk 30. The axial center portion 51 is disposed within the housing 10 so that the shaft axis CL, which is the axis, is coaxial with the axis of the fixed disk 20 and the axis of the drive disk 30.

[0050] The holder portion 52 has a cylindrical shape with a bottom that opens downward in the direction DRa1. The axial center portion 51 of the holder portion 52 is connected to the inside of the tip portion on the upward direction DRa2 side. The tip portion of the holder portion 52 that protrudes outside the main body cover portion 17 is connected to the drive unit 40. This allows the rotational force output by the drive unit 40 to be transmitted to the shaft 50. The rotational force output by the drive unit 40 is transmitted to the drive disk 30 via the shaft 50, the lever 60, and the torsion spring 70. The shaft 50 is connected to the drive disk 30 via the lever 60 and the torsion spring 70.

[0051] The lever 60 is a connecting member that connects the drive disk 30 to the shaft 50. The lever 60 is fixed to the mounting surface 32 of the drive disk 30, and connects the drive disk 30 and the shaft 50 so that they can rotate together while the drive disk 30 is displaceable in the axial direction DRa of the shaft 50.

[0052] The torsion spring 70 is a spring that biases the shaft 50 in the circumferential direction DRc relative to the housing 10. For example, a torsion coil spring that is elastically deformable in the circumferential direction DRc can be used as the torsion spring 70. The torsion spring 70 is disposed between the shaft 50 and the lever 60. The torsion spring 70 is used in a state in which it is twisted and elastically deformed in the circumferential direction DRc. The torsion spring 70 is disposed between the shaft 50 and the lever 60 in a state in which it is compressed in the circumferential direction DRc, with one end of the torsion spring 70 in contact with the lever 60 and the other end of the torsion spring 70 in contact with the holder portion 52 of the shaft 50.

[0053] As a result, the torsion spring 70 generates a biasing force that biases the drive disk 30 to one side in the circumferential direction DRc due to its own elastic deformation. When the rotational force generated by the drive unit 40 is transmitted to the shaft 50, the rotational force is transmitted to the drive disk 30 via the torsion spring 70 and the lever 60. Then, as the shaft 50 rotates, the drive disk 30 rotates integrally with the shaft 50 about the shaft axis CL.

[0054] The compression spring 80 is a biasing member that biases the drive disk 30 toward the fixed disk 20. The compression spring 80 may be, for example, a compression coil spring that is elastically deformable in the axial direction DRa of the shaft 50. The compression spring 80 is disposed inside the housing 10 in a compressed state in the axial direction DRa, with its end on the downward direction DRa1 side contacting the lever 60 and its end on the upward direction DRa2 side contacting the holder portion 52 of the shaft 50. The compression spring 80 is not fixed to at least one of the drive disk 30 and the shaft 50 so that it does not function as a torsion spring 70.

[0055] The compression spring 80 presses the drive disk 30 against the fixed disk 20, thereby maintaining contact between the seal surface 21 of the fixed disk 20 and the sliding surface 31 of the drive disk 30. This contact state is a state in which the seal surface 21 of the fixed disk 20 and the sliding surface 31 of the drive disk 30 are in surface contact. In other words, the valve device 1 can maintain the drive disk 30 in contact with the fixed disk 20.

[0056] The compression spring 80 is disposed so as to surround the shaft axis CL of the shaft 50. In other words, the shaft 50 is disposed inside the compression spring 80. This prevents the load of the compression spring 80 on the drive disk 30 from being biased in the circumferential direction DRc of the shaft 50, making it easier to maintain contact between the seal surface 21 and the sliding surface 31.

[0057] Next, a description will be given of the operation of the valve device 1 of this embodiment. Fluid flows into the fluid passage F of the valve device 1 from the first inlet portion 11 and the second inlet portion 12.

[0058] The fluid that flows in through the first inlet portion 11 and the second inlet portion 12 flows out from one of the first outlet portion 13, the second outlet portion 14, and the third outlet portion 15 depending on the rotational position of the drive disk 30. For example, when the through hole 34 of the drive disk 30 is positioned at a rotational position where it communicates with the flow path hole 23 of the fixed disk 20 that communicates with the first outlet portion 13, the fluid that flows in from the first inlet portion 11 flows out from the first outlet portion 13 via the through hole 34 and the flow path hole 23. When the flow path groove 35 of the drive disk 30 is positioned at a rotational position where it communicates with the flow path hole 23 of the fixed disk 20 that communicates with the first outlet portion 13, the fluid that flows in from the second inlet portion 12 flows out from the first outlet portion 13 via the flow path groove 35 and the flow path hole 23.

[0059] Next, the fixed disk hole 24 and the drive disk hole 33 will be described in detail with reference to FIGS. 3 to 5. As described above, the fixed disk hole 24 of the fixed disk 20 and the drive disk hole 33 of the drive disk 30 are portions through which the axial portion 51 of the shaft 50 is inserted. Specifically, the end portion of the axial portion 51 on the downward direction DRa1 side is inserted into the fixed disk hole 24 and the drive disk hole 33. In other words, the end portion of the axial portion 51 on the downward direction DRa1 side is an insertion portion that is inserted into the fixed disk hole 24 and the drive disk hole 33. The downward direction DRa1 in the axial direction DRa is the shaft insertion direction when the axial portion 51 is inserted into the fixed disk hole 24 and the drive disk hole 33.

[0060] 3, the axial portion 51 has, at its end on the downward direction DRa1 side, a shaft tapered surface 512 that forms a shaft tapered portion 511 whose outer diameter gradually decreases along the downward direction DRa1. The shaft tapered portion 511 has an outer diameter that continuously decreases from the upward direction DRa2 side toward the downward direction DRa1 side in the axial direction DRa, which is the direction along the shaft axis CL. The shaft tapered surface 512 is the portion of the outer peripheral surface of the axial portion 51 that forms the shaft tapered portion 511.

[0061] By configuring the axial portion 51 to have a shaft taper portion 511 at the end portion on the downward DRa1 side in this manner, it becomes easier to insert the axial portion 51 from the upward DRa2 side of the drive disk hole 33 and the fixed disk hole 24 toward the downward DRa1 side.

[0062] As shown in FIG. 4 , the drive disc hole 33 has a drive inlet portion 331 in the mounting surface 32, into which the axial center portion 51 is inserted. The drive inlet portion 331 is open at the mounting surface 32. The drive disc hole 33 has a drive inlet tapered surface 333 that forms a drive inlet tapered portion 332 whose inner diameter gradually decreases in the downward direction DRa1 from the drive inlet portion 331. The drive inlet tapered portion 332 has an inner diameter that continuously decreases from the upward direction DRa2 toward the downward direction DRa1 in the axial direction DRa, which is the direction along the shaft axis CL. In other words, the drive disc hole 33 has a tapered shape on the inlet side, into which the axial center portion 51 is inserted, such that the inner diameter continuously gradually decreases from the downward direction DRa1 toward the upward direction DRa2.

[0063] The drive disc hole 33 also has a drive outlet portion 334 at the sliding surface 31, from which the axial portion 51 inserted into the drive disc hole 33 protrudes. The drive outlet portion 334 opens at the sliding surface 31. The drive disc hole 33 also has a drive outlet tapered surface 336 that forms a drive outlet tapered portion 335 whose inner diameter gradually increases in the downward direction DRa1 toward the drive outlet portion 334. The drive outlet tapered portion 335 has an inner diameter that continuously increases from the upward direction DRa2 toward the downward direction DRa1 in the axial direction DRa, which is the direction along the shaft axis CL. In other words, the drive disc hole 33 is formed in a tapered shape such that the outlet side from which the axial portion 51 protrudes has an inner diameter that continuously gradually increases from the upward direction DRa2 toward the downward direction DRa1.

[0064] As shown in FIG. 5 , the fixed disk hole 24 has a fixed inlet portion 241 on the seal surface 21, into which the axial portion 51 is inserted. The fixed inlet portion 241 opens at the seal surface 21. The fixed disk hole 24 has a fixed inlet tapered surface 243 that forms a fixed inlet tapered portion 242 whose inner diameter gradually decreases from the fixed inlet portion 241 in the downward direction DRa1. The fixed inlet tapered portion 242 has an inner diameter that continuously decreases from the upward direction DRa2 toward the downward direction DRa1 in the axial direction DRa, which is the direction along the shaft axis CL. In other words, the fixed disk hole 24 has a tapered shape on the inlet side, into which the axial portion 51 is inserted, such that the inner diameter continuously gradually decreases from the downward direction DRa1 toward the upward direction DRa2.

[0065] The fixed disk hole 24 also has a fixed outlet portion 244 that allows the axial portion 51 inserted into the fixed disk hole 24 to protrude from the support surface 22. The fixed outlet portion 244 opens at the support surface 22. The fixed disk hole 24 also has a fixed outlet tapered surface 246 that forms a fixed outlet tapered portion 245 whose inner diameter gradually increases in the downward direction DRa1 toward the fixed outlet portion 244. The fixed outlet tapered portion 245 has an inner diameter that continuously increases from the upward direction DRa2 toward the downward direction DRa1 in the axial direction DRa, which is the direction along the shaft axis CL. In other words, the fixed disk hole 24 is formed in a tapered shape such that the outlet side, from which the axial portion 51 protrudes, has an inner diameter that continuously gradually increases from the upward direction DRa2 toward the downward direction DRa1.

[0066] Hereinafter, as shown in FIG. 3 and the like, a virtual plane parallel to the downward direction DRa1, which is the direction in which the axial center portion 51 is inserted into the drive disk hole 33 and the fixed disk hole 24, will be referred to as a virtual plane VS, and the angle formed between the plane along the shaft tapered surface 512 and the virtual plane VS will be referred to as a shaft taper angle θ ｓ 4, the angle formed between the surface along the driving entrance tapered surface 333 and the imaginary surface VS is called the driving entrance angle θ ｄ１ The angle formed by the surface along the drive outlet tapered surface 336 and the imaginary surface VS is called the drive outlet angle θ ｄ２ 5, the angle formed between the surface along the fixed inlet tapered surface 243 and the imaginary surface VS is called the fixed inlet angle θｆ１ The angle formed by the surface along the fixed outlet tapered surface 246 and the imaginary surface VS is called the fixed outlet angle θ ｆ２ It is called.

[0067] In this embodiment, the drive inlet angle θ ｄ１ , drive exit angle θ ｄ２ , fixed inlet angle θ ｆ１ and fixed exit angle θ ｆ２ The angles are equal to each other. ｄ１ , drive exit angle θ ｄ２ , fixed inlet angle θ ｆ１ and fixed exit angle θ ｆ２ is the shaft taper angle θ ｓ It's getting bigger.

[0068] In this embodiment, the drive inlet angle θ ｄ１ and fixed inlet angle θ ｆ１ is the shaft taper angle θ ｓ The reason why the inlet angle is larger than the fixed inlet angle θ ｆ１ is the shaft taper angle θ ｓ The reason for the larger drive inlet angle θ ｄ１ is the shaft taper angle θ ｓ The reason why the fixed inlet angle θ ｆ１ is the shaft taper angle θ ｓ The reason why the drive inlet angle θ is larger will be explained with reference to FIGS. ｄ１ is the shaft taper angle θ ｓ The reason why it is larger is omitted.

[0069] FIG. 6 shows the fixed inlet angle θ ｆ１ and fixed exit angle θ ｆ２ The comparative fixed disk 200 has a large fixed inlet angle θ ｆ１ and fixed exit angle θ ｆ２ is the shaft taper angle θ ｓ As a result, the fixed inlet portion 241 of the comparative fixed disk 200 has a smaller inner diameter than the fixed inlet portion 241 of the fixed disk 20.

[0070] In this way, the fixed inlet angle θ ｆ１ is the shaft taper angle θ ｓ The insertion state when the axial center portion 51 is inserted into the fixed disk hole 24 of the smaller comparative fixed disk 200 will be described. As described above, when the fixed disk 20 is placed in the housing 10, the axial center is positioned coaxially with the shaft axis center CL. Therefore, when the axial center portion 51 is inserted into the fixed disk hole 24, it is desirable that the shaft axis center CL of the axial center portion 51 overlaps with the axis of the fixed disk hole 24. However, as shown in Figures 7 and 8, when the axial center portion 51 is inserted into the fixed disk hole 24, the shaft axis center CL of the axial center portion 51 may be misaligned with the axis of the fixed disk hole 24.

[0071] Here, as shown in the comparative fixed disk 200 of FIG. 7, the fixed inlet angle θ ｆ１ is the shaft taper angle θ ｓ If smaller, fixed inlet angle θ ｆ１ is the shaft taper angle θ ｓ When the inner diameter of the fixed inlet portion 241 is larger than when ..., the inner diameter of the fixed inlet portion 241 is smaller than when the inner diameter of the fixed inlet portion 241 is larger. If the shaft axis CL of the axis portion 51 is misaligned with the axis of the fixed disk hole 24, the tip of the axis portion 51 is likely to collide with the seal surface 21 during insertion. If the tip of the axis portion 51 collides with the seal surface 21, there is a risk that the portion of the seal surface 21 where the axis portion 51 collides will bulge.

[0072] Also, fixed inlet angle θ ｆ１ is the shaft taper angle θ ｓ If the distance is smaller than this, when the shaft is inserted with the shaft axis CL of the axial center portion 51 misaligned with the axis of the fixed disk hole 24, the shaft tapered surface 512 is likely to slide against the area surrounding the fixed inlet portion 241. When the shaft tapered surface 512 slides against the area surrounding the fixed inlet portion 241, the area of ​​the seal surface 21 that forms the fixed inlet portion 241 may bulge.

[0073] If a portion of the seal surface 21 is raised, when the sliding surface 31 and the seal surface 21 slide and rotate, the sliding surface 31 is depressed by the raised portion of the seal surface 21, which causes fluid to leak from between the sliding surface 31 and the seal surface 21.

[0074] In contrast, a fixed inlet angle θ ｆ１ is the shaft taper angle θ ｓ If larger, fixed inlet angle θ ｆ１ is the shaft taper angle θ ｓ The fixed inlet portion 241 has a larger inner diameter than when the fixed inlet portion 241 is smaller. Therefore, even if the shaft axis CL of the axial portion 51 is misaligned with the axis of the fixed disk hole 24, as in the fixed disk 20 shown in Figure 8, the tip of the axial portion 51 is less likely to collide with the seal surface 21 during insertion. Therefore, the bulge of the seal surface 21 caused by the tip of the axial portion 51 colliding with the seal surface 21 is suppressed.

[0075] Also, fixed inlet angle θ ｆ１ is the shaft taper angle θ ｓ If the distance is larger, even if the axial center portion 51 is inserted with the shaft axis CL of the axial center portion 51 and the axis of the fixed disk hole 24 misaligned, the shaft tapered surface 512 is less likely to slide on the area surrounding the fixed inlet portion 241. Furthermore, even if the axial center portion 51 is inserted with the shaft axis CL of the axial center portion 51 and the axis of the fixed disk hole 24 misaligned, the axial center portion 51 can be inserted into the fixed disk hole 24 while the tip of the axial center portion 51 slides on the fixed inlet tapered surface 243. Therefore, bulging of the seal surface 21 caused by the shaft tapered surface 512 sliding on the area surrounding the fixed inlet portion 241 is suppressed.

[0076] This makes it difficult for depressions to occur in the sliding surface 31 due to the swelling of the sealing surface 21. As a result, leakage of fluid from between the sliding surface 31 and the sealing surface 21 can be suppressed.

[0077] In this way, the fixed inlet angle θ ｆ１ is the shaft taper angle θ ｓIf it is larger, it is possible to suppress the bulging of the seal surface 21 caused by collision between the seal surface 21 and the tip of the axial center portion 51 and sliding between the part surrounding the fixed inlet portion 241 and the shaft tapered surface 512.

[0078] And the drive inlet angle θ ｄ１ is the shaft taper angle θ ｓ If the diameter is larger, for the same reason, it is possible to suppress the bulging of the mounting surface 32 caused by collision between the mounting surface 32 and the tip of the axial center portion 51 and sliding between the portion surrounding the drive inlet portion 331 and the shaft tapered surface 512.

[0079] The drive disk hole 33 of this embodiment is tapered such that the entrance side, into which the axial portion 51 is inserted, has an inner diameter that increases upward in the DRa2 direction, and the exit side, from which the axial portion 51 protrudes, has an inner diameter that increases downward in the DRa1 direction. The fixed disk hole 24 of this embodiment is tapered such that the entrance side, into which the axial portion 51 is inserted, has an inner diameter that increases upward in the DRa2 direction, and the exit side, from which the axial portion 51 protrudes, has an inner diameter that increases downward in the DRa1 direction.

[0080] Therefore, a gap is formed between the inner peripheral surface of the drive disk hole 33 and the outer peripheral surface of the axial center portion 51 on both the inlet side and the outlet side of the drive disk hole 33. Also, a gap is formed between the inner peripheral surface of the fixed disk hole 24 and the outer peripheral surface of the axial center portion 51 on both the inlet side and the outlet side of the fixed disk hole 24.

[0081] Therefore, even if foreign matter is mixed in the fluid flowing through the fluid passage F, the foreign matter can be introduced into the gap formed in the drive disk hole 33 or the gap formed in the fixed disk hole 24. This prevents foreign matter from flowing between the seal surface 21 and the sliding surface 31, damaging the seal surface 21 and the sliding surface 31, and causing the fluid to leak from between the sliding surface 31 and the seal surface 21.

[0082] As described above, the valve device 1 of this embodiment includes a housing 10 that defines a fluid passage F therein through which a fluid flows, a drive unit 40 that outputs a rotational force, and a shaft 50 that rotates about a shaft axis CL by the rotational force. The valve device 1 also includes a fixed disk 20 that is disposed inside the housing 10 and that defines a fluid passage hole 23 through which the fluid flows and a fixed disk hole 24 through which the shaft 50 is inserted. The valve device 1 also includes a drive disk 30 that increases or decreases the opening degree of the fluid passage hole 23 as the shaft 50 rotates and slides on the fixed disk 20 to rotate about the shaft axis CL. The shaft 50 includes an axial portion 51 that is inserted into the fixed disk hole 24 at one end in the axial direction DRa, which is the direction along the shaft axis CL. The axial portion 51 includes a shaft tapered surface 512 that defines a shaft tapered portion 511 whose outer diameter gradually decreases along the axial direction DRa. The drive disk 30 has a sliding surface 31 that slides against the fixed disk 20 on the downward direction DRa1 side, which is one side in the axial direction DRa. The fixed disk 20 has a sealing surface 21 that faces the sliding surface 31 on the upward direction DRa2 side, which is the other side in the axial direction DRa. The fixed disk hole 24 has a fixed inlet portion 241 into which the shaft 50 is inserted at the sealing surface 21, and also has a fixed inlet tapered surface 243 that forms a fixed inlet tapered portion 242 whose inner diameter gradually decreases from the fixed inlet portion 241 along the downward direction DRa1. The fixed inlet tapered portion 242 has a fixed inlet angle θ, which is the angle formed between a plane along the fixed inlet tapered surface 243 and an imaginary plane VS. ｆ１ is the shaft taper angle θ, which is the angle formed between the surface along the shaft taper surface 512 and the imaginary plane VS. ｓ Greater than.

[0083] With this, even if the shaft axis CL of the axis portion 51 is misaligned with the axis of the fixed disk hole 24, the tip of the axis portion 51 is less likely to collide with the seal surface 21 during insertion. Therefore, the bulge of the seal surface 21 caused by the tip of the axis portion 51 colliding with the seal surface 21 is suppressed.

[0084] Furthermore, according to this, even if the axial center portion 51 is inserted with the shaft axis CL of the axial center portion 51 and the axis of the fixed disk hole 24 misaligned, the shaft tapered surface 512 is less likely to slide on the area surrounding the fixed inlet portion 241. Furthermore, even if the axial center portion 51 is inserted with the shaft axis CL of the axial center portion 51 and the axis of the fixed disk hole 24 misaligned, the axial center portion 51 can be inserted into the fixed disk hole 24 while the tip of the axial center portion 51 slides on the fixed inlet tapered surface 243. Therefore, bulging of the seal surface 21 caused by the shaft tapered surface 512 sliding on the area surrounding the fixed inlet portion 241 is suppressed.

[0085] Therefore, damage to the sliding surface 31 due to the swelling of the seal surface 21 is less likely to occur, and as a result, leakage of fluid from between the sliding surface 31 and the seal surface 21 can be suppressed.

[0086] Furthermore, at the entrance side where the axial center portion 51 of the fixed disk hole 24 is inserted, a gap is formed between the inner peripheral surface of the fixed disk hole 24 and the outer peripheral surface of the axial center portion 51 .

[0087] Therefore, even if foreign matter is mixed in the fluid flowing through the fluid passage F, the foreign matter can be introduced into the gap formed in the fixed disk hole 24. This prevents foreign matter from flowing between the seal surface 21 and the sliding surface 31, damaging the seal surface 21 and the sliding surface 31, and preventing fluid from leaking from between the sliding surface 31 and the seal surface 21.

[0088] Furthermore, according to the above embodiment, the following effects can be obtained.

[0089] (1) In the above embodiment, the fixed disk hole 24 is formed to penetrate the fixed disk 20, and has a fixed outlet portion 244 on the surface on the downward direction DRa1 side from which the axial portion 51 inserted into the fixed disk hole 24 protrudes. The fixed disk hole 24 also has a fixed outlet tapered surface 246 that forms a fixed outlet tapered portion 245 whose inner diameter gradually increases along the downward direction DRa1 to the fixed outlet portion 244.

[0090] As a result, a gap is formed between the inner peripheral surface of the fixed disk hole 24 and the outer peripheral surface of the axial center portion 51 at the exit side where the axial center portion 51 of the fixed disk hole 24 protrudes.

[0091] Therefore, even if foreign matter is mixed in the fluid flowing through the fluid passage F, the foreign matter can be introduced into the gap formed on the inlet side of the fixed disk hole 24. This prevents foreign matter from flowing between the seal surface 21 and the sliding surface 31, damaging the seal surface 21 and the sliding surface 31, and preventing fluid from leaking from between the sliding surface 31 and the seal surface 21.

[0092] (2) In the above embodiment, the drive disk 30 is formed with a drive disk hole 33 through which the axial center portion 51 is inserted. The drive disk hole 33 has, on the surface on the upward direction DRa2 side, a drive inlet portion 331 through which the axial center portion 51 is inserted, and a drive inlet tapered surface 333 that forms a drive inlet tapered portion 332 whose inner diameter gradually decreases from the drive inlet portion 331 along the downward direction DRa1. The drive inlet tapered portion 332 has a drive inlet angle θ, which is the angle formed between a plane along the drive inlet tapered surface 333 and an imaginary plane VS. ｄ１ is the shaft taper angle θ, which is the angle formed between the surface along the shaft taper surface 512 and the imaginary plane VS. ｓ Greater than.

[0093] This makes it possible to prevent the mounting surface 32 from colliding with the tip of the axial center portion 51 and the bulging of the mounting surface 32 caused by sliding between the portion surrounding the drive inlet portion 331 and the shaft tapered surface 512.

[0094] Furthermore, at the entrance side where the axial center portion 51 of the drive disk hole 33 is inserted, a gap is formed between the inner peripheral surface of the drive disk hole 33 and the outer peripheral surface of the axial center portion 51 .

[0095] Therefore, even if foreign matter is mixed in the fluid flowing through the fluid passage F, the foreign matter can be introduced into the gap formed on the inlet side of the drive disk hole 33. This prevents foreign matter from flowing between the seal surface 21 and the sliding surface 31, damaging the seal surface 21 and the sliding surface 31, and preventing fluid from leaking from between the sliding surface 31 and the seal surface 21.

[0096] (3) In the above embodiment, the drive disc hole 33 is formed to penetrate the drive disc 30, and has a drive outlet portion 334 on the surface on the downward direction DRa1 side from which the axial portion 51 inserted into the drive disc hole 33 protrudes. The drive disc hole 33 also has a drive outlet tapered surface 336 that forms a drive outlet tapered portion 335 whose inner diameter gradually increases along the downward direction DRa1 to the drive outlet portion 334.

[0097] As a result, a gap is formed between the inner peripheral surface of the drive disk hole 33 and the outer peripheral surface of the axial center portion 51 at the exit side where the axial center portion 51 of the drive disk hole 33 protrudes.

[0098] Therefore, even if foreign matter is mixed in the fluid flowing through the fluid passage F, the foreign matter can be introduced into the gap formed on the outlet side of the drive disk hole 33. This prevents foreign matter from flowing between the seal surface 21 and the sliding surface 31, damaging the seal surface 21 and the sliding surface 31, and preventing fluid from leaking from between the sliding surface 31 and the seal surface 21.

[0099] Other Embodiments Although typical embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be modified in various ways, for example, as follows.

[0100] In the above-described embodiment, the valve device 1 has been described as being used in a fluid circulation system mounted on, for example, an electric vehicle or a hybrid vehicle, but is not limited thereto. For example, the valve device 1 may be used in a fluid circulation system mounted on a vehicle other than an electric vehicle or a hybrid vehicle. Furthermore, the valve device 1 may be used for purposes other than vehicles.

[0101] In the above embodiment, the fluid flowing through the fluid passage F in the housing 10 of the valve device 1 is described as coolant, but this is not limited thereto. For example, the fluid may be a liquid or gas other than coolant.

[0102] In the above-described embodiment, the fixed disk hole 24 has a fixed outlet tapered surface 246 that forms a fixed outlet tapered portion 245 whose inner diameter gradually increases along the downward direction DRa1 up to the fixed outlet portion 244, but this is not limited to this.

[0103] For example, the fixed disk hole 24 may have a shape that does not include the fixed outlet taper 245 that gradually increases in inner diameter to the fixed outlet 244 .

[0104] In the above-described embodiment, an example was described in which the drive disk hole 33 has a drive inlet tapered surface 333 that forms a drive inlet tapered portion 332 whose inner diameter gradually decreases from the drive inlet portion 331 along the downward direction DRa1, but this is not limited to this.

[0105] For example, the drive disk hole 33 may not have the drive inlet tapered portion 332 in which the inner diameter gradually decreases from the drive inlet portion 331 in the downward direction DRa1.

[0106] In the above-described embodiment, an example was described in which the drive disk hole 33 has a drive outlet tapered surface 336 that forms a drive outlet tapered portion 335 whose inner diameter gradually increases along the downward direction DRa1 to the drive outlet portion 334, but this is not limited to this.

[0107] For example, the drive disk hole 33 may not have the drive outlet tapered portion 335 in which the inner diameter gradually increases to the drive outlet portion 334 .

[0108] In the above-described embodiments, it goes without saying that the elements constituting the embodiments are not necessarily essential unless they are specifically stated as essential or are clearly considered essential in principle.

[0109] In the above-described embodiments, when numerical values ​​such as the number, values, amounts, ranges, etc. of components of the embodiments are mentioned, they are not limited to the specific numbers unless they are specifically stated as essential or are clearly limited to a specific number in principle.

[0110] In the above-described embodiments, when referring to the shapes, positional relationships, etc. of components, etc., the shapes, positional relationships, etc. are not limited to those unless otherwise specified or when they are fundamentally limited to specific shapes, positional relationships, etc.

Claims

1. A valve device comprising: a housing (10) forming a fluid passage therein for circulating a fluid; a drive unit (40) for outputting a rotational force; a shaft (50) that rotates about a shaft axis (CL) by the rotational force; a fixed disk (20) disposed inside the housing and having a flow passage hole (23) through which the fluid flows and a fixed disk hole (24) through which the shaft is inserted; and a drive disk (30) that increases or decreases the opening of the flow passage hole as the shaft rotates and slides on the fixed disk to rotate about the shaft axis, wherein the shaft has an insertion portion (51) that is inserted into the fixed disk hole at one end in the axial direction that is along the shaft axis, and the insertion portion has a shaft tapered surface (512) that forms a shaft tapered portion (511) whose outer diameter gradually decreases along the shaft insertion direction when the direction in which the shaft is inserted into the fixed disk hole is defined as the shaft insertion direction, a valve device in which the drive disk has a sliding surface (31) that slides against the fixed disk on one side in the shaft insertion direction, the fixed disk has a sealing surface (21) that faces the sliding surface on the other side in the shaft insertion direction, the fixed disk hole has a fixed inlet portion (241) through which the shaft is inserted onto the sealing surface, and has a fixed inlet tapered surface (243) that forms a fixed inlet tapered portion (242) whose inner diameter gradually decreases from the fixed inlet portion along the shaft insertion direction, and the fixed inlet tapered portion has an angle formed by a surface along the fixed inlet tapered surface and an imaginary plane (VS) parallel to the shaft insertion direction that is larger than the angle formed by a surface along the shaft tapered surface and the imaginary plane.

2. The valve device according to claim 1, wherein the fixed disk hole is formed through the fixed disk and has a fixed outlet portion (244) on one side in the shaft insertion direction that allows the shaft inserted into the fixed disk hole to protrude, and also has a fixed outlet tapered surface (246) that forms a fixed outlet tapered portion (245) whose inner diameter gradually increases along the shaft insertion direction up to the fixed outlet portion.

3. A valve device as set forth in claim 1 or 2, wherein the drive disc has a drive disc hole (33) formed therein through which the shaft is inserted, the drive disc hole having a drive inlet portion (331) through which the shaft is inserted on the surface on the other side in the shaft insertion direction, and a drive inlet tapered surface (333) forming a drive inlet tapered portion (332) whose inner diameter gradually decreases from the drive inlet portion along the shaft insertion direction, and the drive inlet tapered portion has an angle formed between a surface along the drive inlet tapered surface and the imaginary plane that is larger than the angle formed between a surface along the shaft tapered surface and the imaginary plane.

4. A valve device as described in claim 3, wherein the drive disk hole is formed through the drive disk and has a drive outlet portion (334) on one side surface in the shaft insertion direction that allows the shaft inserted into the drive disk hole to protrude, and also has a drive outlet tapered surface (336) that forms a drive outlet tapered portion (335) whose inner diameter gradually increases along the shaft insertion direction up to the drive outlet portion.

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