阅读说明：本技术 阀装置 (Valve device ) 是由 原田浩行 守谷勇一朗 菅原岳大 于 2020-03-19 设计创作，主要内容包括：阀装置具备：壳体(10),具有形成阀室(11)的阀室内壁(101)、形成与阀室连通的收容空间(14)的收容空间内壁(104)；阀部件(20),具有阀部件主体部(21)；阀座部件(30),形成阀座流路(31)；环状的固定部件(52),将阀座部件固定在壳体；以及环状的壳体侧密封部(45),阻止阀座部件与收容空间内壁之间的流体的流通。阀座部件具有在内侧形成阀座流路的筒部(32)以及与筒部相连的凸缘部(33)。通过在沿着轴线的方向上在收容空间内壁的对置面(114)与固定部件之间夹着凸缘部,阀座部件被固定在壳体。在固定部件与收容空间内壁之间气密的状态下,固定部件相对于收容空间内壁被固定。壳体侧密封部主要由橡胶材料构成,被夹在凸缘部与固定部件之间。(The valve device is provided with: a housing (10) having a valve chamber inner wall (101) forming a valve chamber (11), and a housing space inner wall (104) forming a housing space (14) communicating with the valve chamber; a valve member (20) having a valve member main body (21); a valve seat member (30) that forms a valve seat flow path (31); an annular fixing member (52) for fixing the valve seat member to the housing; and an annular housing-side seal portion (45) that blocks the flow of fluid between the valve seat member and the inner wall of the housing space. The valve seat member has a cylindrical portion (32) in which a valve seat flow path is formed, and a flange portion (33) connected to the cylindrical portion. The valve seat member is fixed to the housing by sandwiching the flange portion between a facing surface (114) of the inner wall of the housing space and the fixing member in a direction along the axis. The fixing member is fixed to the inner wall of the housing space in an airtight state between the fixing member and the inner wall of the housing space. The case-side seal portion is mainly made of a rubber material and is sandwiched between the flange portion and the fixing member.)

1. A valve device is provided, which comprises a valve body,

the disclosed device is provided with:

a housing (10) having a valve chamber inner wall (101) forming a valve chamber (11), and a housing space inner wall (104) forming a housing space (14) communicating with the valve chamber;

a valve member (20) which is housed in the valve chamber and has a cylindrical or spherical valve member main body (21);

a valve seat member (30) that is housed in the housing space and forms a valve seat flow path (31) that is opened and closed by the valve member main body;

an annular fixing member (52) which is accommodated in the accommodation space and fixes the valve seat member to the housing; and

annular housing-side sealing portions (45, 61) which are accommodated in the accommodation space and prevent the flow of fluid between the valve seat member and the inner wall of the accommodation space,

the valve seat member includes: a cylinder (32) in which the valve seat flow path is formed; and a flange portion (33) connected to the opposite side of the cylindrical portion to the valve chamber side and including a portion protruding in a ring shape to the outside of the cylindrical portion than the cylindrical portion,

the inner wall of the housing space includes an annular facing surface (114) facing the flange in a direction along an axis (CL) of the flange,

the valve seat member is fixed to the housing by sandwiching the flange portion between the facing surface and the fixing member in a direction along the axis,

The fixing member is fixed to the inner wall of the housing space in an airtight state between the fixing member and the inner wall of the housing space,

the housing-side seal portion is mainly made of a rubber material and is sandwiched between the flange portion and the fixing member.

2. The valve device as claimed in claim 1,

the valve device comprises a spring member (51) for pressing the valve seat member to the housing by a reaction force generated during elastic deformation,

the spring member is mainly made of a metal material or a synthetic resin material, and is sandwiched between the flange portion and the fixing member at a position on the inner circumferential side or the outer circumferential side of the case-side seal portion.

3. The valve device as claimed in claim 2,

the spring member is disposed on the outer peripheral side of the housing-side seal portion,

the facing surface has a contact end (114a) which is an end portion on the inner peripheral side of a region in contact with the flange portion,

at least a part of the housing-side sealing portion is disposed on an inner peripheral side of the contact end,

the housing-side seal portion and the spring member are sandwiched between the flange portion and the fixed member, and a reaction force generated in the housing-side seal portion by elastic deformation is smaller than a reaction force generated in the spring member by elastic deformation.

4. A valve device according to any one of claims 1 to 3,

the housing-side seal portion and the valve seat member are formed as an integrally molded product.

5. The valve device as claimed in claim 4,

the valve device includes:

valve member-side sealing portions (42, 44) provided on the valve chamber side in the cylindrical portion, and coming into contact with the valve member main body portion to close a gap between the valve member main body portion and the valve seat member; and

a connecting portion (411, 412, 431, 41, 43, 48, 49) connecting the valve member side seal portion and the housing side seal portion;

the valve member side seal portion, the housing side seal portion, and the coupling portion are made of the same material and are continuous without a seam.

Technical Field

The present disclosure relates to valve devices.

Background

Patent document 1 discloses a valve device. In this valve device, the valve member and the valve seat member are housed in a housing. The valve seat member includes a cylindrical portion in which a valve seat flow passage is formed, and an annular flange portion projecting from the cylindrical portion to the outside of the cylindrical portion. An inner wall of the housing, which forms a space for accommodating the valve seat member, includes an annular facing surface facing the flange portion. The flange portion is sandwiched between the facing surface and the annular fixing member, whereby the valve seat member is fixed to the housing.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2018-91321

Disclosure of Invention

In the above-described conventional valve device, the facing surface is in contact with the surface of one of the facing surfaces of the flange portion, thereby sealing the space between the valve seat member and the housing. However, the inventors of the present application have found that, when at least one of the facing surface and the one surface of the flange portion has low flatness, a gap is generated between the stepped surface and the one surface of the flange portion. Therefore, when the valve member closes the valve seat flow path, the fluid can flow through the gap between the stepped surface and the one surface of the flange portion, and the fluid can flow between the housing and the valve seat member. That is, leakage of fluid occurs.

An object of the present disclosure is to provide a valve device capable of preventing the passage of fluid between a housing and a valve seat member.

According to one aspect of the present disclosure, a valve device includes: a housing having a valve chamber inner wall forming a valve chamber, and a housing space inner wall forming a housing space communicating with the valve chamber; a valve member, which is housed in the valve chamber, and which has a cylindrical or spherical valve member main body; a valve seat member that is accommodated in the accommodation space and forms a valve seat flow path that is opened and closed by the valve member main body; an annular fixing member accommodated in the accommodation space and fixing the valve seat member to the housing; and an annular housing-side seal portion that is housed in the housing space and that prevents the flow of fluid between the valve seat member and the inner wall of the housing space; the valve seat member has: a cylinder part, wherein a valve seat flow path is formed inside the cylinder part; and a flange portion connected to an opposite side of the cylindrical portion to the valve chamber side and including a portion protruding in a ring shape to an outer side of the cylindrical portion than the cylindrical portion, an inner wall of the housing space including a ring-shaped facing surface facing the flange portion in a direction along an axis of the flange portion, the flange portion being sandwiched between the facing surface and the fixing member in the direction along the axis, and the valve seat member being fixed to the housing; the fixing member is fixed relative to the inner wall of the accommodating space in an airtight state between the fixing member and the inner wall of the accommodating space; the case-side seal portion is mainly made of a rubber material and is sandwiched between the flange portion and the fixing member.

Thereby, the case-side seal portion is sandwiched between the flange portion and the fixing member. The case-side seal portion can prevent the fluid from flowing between the flange portion and the fixed member. Further, the fixing member is in an airtight state with the inner wall of the housing space. This can prevent the fluid from flowing between the valve seat member and the housing.

The parenthesized reference numerals given to the respective components and the like are examples of correspondence relationships between the components and the like and specific components and the like described in the embodiments described later.

Drawings

Fig. 1 is a schematic diagram of an engine system to which the valve device of embodiment 1 is applied.

Fig. 2 is an external view of the valve device of embodiment 1.

Fig. 3 is a sectional view III-III in fig. 2.

Fig. 4 is a sectional view of the valve device in the same section as fig. 3, and is a view different from the position of the valve member in fig. 3.

Fig. 5 is a perspective view of a valve member provided in the valve device of embodiment 1.

Fig. 6 is a partial sectional view of the valve device of embodiment 1.

Fig. 7 is a sectional view of a valve seat member provided in the valve device according to embodiment 1.

Fig. 8 is a perspective view of a valve seat member provided in the valve device according to embodiment 1.

Fig. 9 is a plan view of a wave washer provided in the valve device according to embodiment 1.

Fig. 10 is a side view of a wave washer provided in the valve device according to embodiment 1.

Fig. 11 is a front view of the valve seat member of embodiment 1 as viewed from the flange portion side.

Fig. 12A is a partial sectional view of the valve device according to embodiment 1 showing a state in which the first protrusion is in contact with the sealing surface of the valve member.

Fig. 12B is a partial sectional view of the valve device according to embodiment 1 showing a state in which the first projection is pushed down by the sealing surface of the valve member.

Fig. 13 is a partial sectional view of the valve device of comparative example 1.

Fig. 14 is a schematic diagram for explaining the moment acting on the flange portion in the first arrangement example of the valve device of embodiment 1.

Fig. 15 is a schematic diagram for explaining the moment acting on the flange portion in the second arrangement example of the valve device of embodiment 1.

Fig. 16 is a front view of the valve seat member of embodiment 2 when the valve seat member is viewed from the side opposite to the flange portion.

Fig. 17 is a cross-sectional view of XVII-XVII in fig. 16.

Fig. 18 is a partial sectional view of the valve device of embodiment 3.

Fig. 19 is a partial sectional view of the valve device of embodiment 4.

Fig. 20 is a partial sectional view of the valve device of his embodiment.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, the same or equivalent portions are denoted by the same reference numerals and described.

(embodiment 1)

As shown in fig. 1, the valve device 1 of the present embodiment is applied to an engine system 90 that generates driving force by burning fuel.

[ Structure of Engine System ]

First, the engine system 90 will be explained. The engine system 90 includes an engine 91, an intake system 92, an exhaust system 93, a supercharger 94, an exhaust gas recirculation system 95, and the like. The engine 91 houses a piston 912 in a cylinder 911 to form a combustion chamber 910.

The intake system 92 supplies air from the outside air to the engine 91. The intake system 92 includes an intake pipe 921, an intake manifold 922, an air cleaner 923, an intercooler 924, a throttle valve 925, and the like. Hereinafter, the air supplied to the engine 91 is referred to as intake air.

The intake pipe 921 is a pipe for introducing intake air into the combustion chamber 910, and forms an intake passage 920. The intake pipe 921 has one end opened to the outside air and the other end connected to an intake manifold 922. The intake manifold 922 is connected to the other end of the intake pipe 921 and the engine 91. The intake manifold 922 has a configuration that branches into the same number of passages as the number of cylinders 911. The air cleaner 923 removes foreign matter from air taken in from the atmosphere. Intercooler 924 cools the intake air compressed and warmed by compressor 941 of supercharger 94. The throttle valve 925 adjusts the intake air amount of the engine 91. The throttle valve 925 is electrically connected to the electronic control unit 96. Hereinafter, the electronic control unit is referred to as an ECU.

The exhaust system 93 discharges exhaust gas discharged from the engine 91 to the outside. The exhaust system 93 includes an exhaust pipe 931, an exhaust manifold 932, and an exhaust purification unit 933. The exhaust pipe 931 is a pipe for guiding the exhaust gas of the engine 91 to the atmosphere, and forms an exhaust passage 930. The exhaust manifold 932 is connected to one end of an exhaust pipe 931 and the engine 91. The exhaust manifold 932 has a structure in which the same number of passages as the number of cylinders 911 are merged. The exhaust gas purification unit 933 is provided at the exhaust pipe 931. The exhaust gas purification unit 933 decomposes the hydrocarbon contained in the exhaust gas or traps particulate matter.

The supercharger 94 compresses intake air in the intake pipe 921 by the energy of exhaust gas, and pressurizes and supplies the pressurized intake air to the combustion chamber 910. The supercharger 94 includes a compressor 941, a turbine 942, and a shaft 943. The compressor 941 is disposed between the air cleaner 923 and the intercooler 924 in the intake passage 920. The compressor 941 can compress intake air. The turbine 942 is disposed between the exhaust manifold 932 and the exhaust gas purification unit 933 in the exhaust passage 930. The turbine 942 is rotationally driven by the energy of the exhaust gas. The shaft 943 couples the compressor 941 and the turbine 942. The compressor 941 and the turbine 942 are rotated in synchronization by a shaft 943.

The exhaust gas recirculation system 95 recirculates the exhaust gas having passed through the turbine 942 to the intake passage 920, and supplies the recirculated exhaust gas to the combustion chamber 910 together with the air having passed through the air cleaner 923. The exhaust gas recirculation system 95 includes an EGR pipe 951, an EGR cooler 952, and a valve device 1.

The EGR pipe 951 connects the downstream side of the exhaust purification unit 933 of the exhaust pipe 931 to the upstream side of the compressor 941 of the intake pipe 921. The EGR pipe 951 forms an EGR passage 950 that returns the exhaust gas having passed through the turbine 942 to the air before compression by the compressor 941. The EGR cooler 952 is provided in the EGR pipe 951. The EGR cooler 952 cools the gas passing through the EGR passage 950.

The valve device 1 is provided at a portion where the EGR pipe 951 is connected to the intake pipe 921. The valve device 1 increases or decreases the flow rate of the exhaust gas flowing into the intake passage 920 via the EGR passage 950. The valve device 1 is electrically connected to the ECU 96.

The ECU96 is constituted by a microcomputer or the like having a CPU as a calculation unit and a RAM, a ROM, and the like as a storage unit. The ECU96 controls the driving of the throttle valve 925 and the valve device 1 in accordance with the driving conditions of the vehicle or device in which the engine system 90 is mounted and the operation content of the operator who operates the vehicle or device.

[ Structure of valve device ]

Next, the structure of the valve device 1 will be explained. The valve device 1 is a rotary valve in which the opening degree of a fluid passage can be increased or decreased by rotationally driving a cylindrical valve member. The valve device 1 can increase or decrease the opening degree of the EGR passage 950 with respect to the intake passage 920.

As shown in fig. 2, 3, and 4, the valve device 1 includes a housing 10, a valve member 20, and a valve seat member 30. In fig. 4 the same cross section of the valve device 1 as shown in fig. 3 is shown. The position of the valve member 20 of fig. 4 is different from the position of the valve member 20 of fig. 3.

The housing 10 forms a junction of the intake passage 920 and the EGR passage 950. The housing 10 is formed to be able to house the valve member 20. The case 10 is composed of only a metal material. As the metal material, an aluminum alloy may be mentioned. In addition, the case 10 may be mainly made of a metal material. That is, the housing 10 may be made of a metal material or other materials.

As shown in fig. 3 and 4, the housing 10 has a valve chamber inner wall 101 forming the valve chamber 11, a first flow path inner wall 102 forming the upstream flow path 12, a second flow path inner wall 103 forming the downstream flow path 13, and a housing space inner wall 104 forming the housing space 14. The inner wall is an inner wall surface.

The valve chamber 11 is formed to rotatably house the valve member 20. The upstream side flow passage 12 is formed to communicate with the valve chamber 11. The upstream flow path 12 communicates with an air cleaner 923. The downstream flow passage 13 is formed to communicate with the upstream flow passage 12 and the valve chamber 11. The downstream flow path 13 is formed coaxially with the upstream flow path 12. The downstream flow path 13 communicates with the intercooler 924. The housing space 14 is formed to communicate with the upstream side flow passage 12 and the downstream side flow passage 13 separately from the valve chamber 11. The accommodation space 14 is formed to accommodate the valve seat member 30. The housing space 14 communicates with the EGR passage 950.

The valve member 20 is housed in the valve chamber 11. The valve member 20 opens and closes the seat flow path 31 of the seat member 30. The valve member 20 is provided to be relatively rotatable with respect to the housing 10. The valve member 20 is driven by an electric motor, not shown. Here, the direction of rotation of the valve member 20 from the state of fig. 3 to the state of fig. 4 is referred to as the "EGR passage blocking direction" for convenience. The direction rotated from the state of fig. 4 to the state of fig. 3 is referred to as an "EGR passage opening direction".

The valve seat member 30 is accommodated in the accommodation space 14. The valve seat member 30 is a member separate from the housing 10. The seat member 30 is a member forming a seat flow path 31 opened and closed by the valve member 20. Since the housing space 14 communicates with the EGR passage 950, the seat passage 31 communicates with the EGR passage 950.

The valve seat member 30 is composed of only a synthetic resin material. The valve seat member 30 may be mainly made of a synthetic resin material. That is, the valve seat member 30 may be made of a synthetic resin material or another material. The synthetic resin material is a material other than synthetic fibers and synthetic rubbers in the synthetic polymer compound.

As shown in fig. 5, the valve member 20 has a valve member main body portion 21, an upper arm 22, a lower arm 23, an upper shaft 24, and a lower shaft 25.

The valve member main body portion 21 is cylindrical. The outer wall surface 211 of the valve member body 21 is formed in the same shape as a part of the wall surface on the outer side in the radial direction of the cylinder. The outer wall surface 211 has sealing surfaces 212, 213 and connecting sealing surfaces 214, 215.

The sealing surfaces 212 and 213 are formed in the outer wall surface 211 so as to face the circumferential direction of the valve member main body 21. The sealing surface 212 has the same shape as a part of the inner wall surface of the side wall of the cylinder. The sealing surface 212 is semi-cylindrical with a central angle of 180 degrees. The sealing surface 212 is formed to have a larger radius than that of the sealing surface 213. The sealing surface 213 has the same shape as a part of the outer wall surface of the side wall of the cylinder. The sealing surface 213 is a semi-cylindrical shape having a central angle of 180 degrees. The imaginary cylindrical surface including the seal surface 212 and the imaginary cylindrical surface including the seal surface 213 have the center axis on the same axis. The central axis is orthogonal to the axis of rotation of the valve member 20.

The connecting sealing surfaces 214, 215 are formed orthogonally to the sealing surfaces 212, 213. The normal lines connecting the sealing surfaces 214, 215 can be orthogonal to the rotation axis of the valve member 20 if they are moved in parallel. The connecting seal surface 214 is located on the upper arm 22 side in the region where the seal surface 212 and the seal surface 213 are connected. The connecting seal surface 215 is located on the lower arm 23 side in the region where the seal surface 212 and the seal surface 213 are connected.

The upper arm 22 and the lower arm 23 are formed in a substantially fan shape. The upper arm 22 is provided at one axial end of the valve member main body 21. The lower arm 23 is provided at the other axial end of the valve member main body 21. The valve member body 21, the upper arm 22, and the lower arm 23 are made of only a synthetic resin material. Examples of the synthetic resin material include materials having high heat resistance, such as polyphenylene sulfide. The valve member main body 21, the upper arm 22, and the lower arm 23 may be mainly made of a synthetic resin material. That is, the valve member main body 21, the upper arm 22, and the lower arm 23 may be made of a synthetic resin material or another material.

The upper shaft 24 and the lower shaft 25 are rotation shafts of the valve member 20. The upper shaft 24 and the lower shaft 25 are substantially rod-shaped members made of a metal material such as stainless steel. An upper shaft 24 is provided on the upper arm 22. The upper shaft 24 extends from the upper arm 22 in a direction away from the valve member main body 21. The lower shaft 25 is provided at the lower arm 23. The lower shaft 25 extends from the lower arm 23 in a direction away from the valve member main body 21. The upper shaft 24 and the lower shaft 25 are rotatably supported by bearings, not shown, provided in the housing 10.

As shown in fig. 6, 7, and 8, the valve seat member 30 includes a cylindrical portion 32 and a flange portion 33. The cylindrical portion 32 has a seat flow passage 31 formed therein. The cylindrical portion 32 extends in the axial direction, which is a direction parallel to the axis CL. The flange portion 33 is connected to the opposite side of the cylindrical portion 32 from the valve chamber 11 side. The flange portion 33 includes a portion that protrudes in a ring shape outward from the cylindrical portion 32. In other words, the flange portion 33 is a plate-like portion that is annularly enlarged at an end portion of the valve seat member 30. The axis CL is a center line of the cylindrical portion 32 and also a center line of the flange portion 33. The flange portion 33 has one surface 331 located on one side in the axial direction of the flange portion 33, and another surface 332 located on the other side in the axial direction of the flange portion 33.

The cylindrical portion 32 has a first side wall portion 321 and a second side wall portion 322. The first side wall 321 and the second side wall 322 are formed in the same shape as a part of the side wall of the cylinder. The first and second side wall portions 321 and 322 are formed to have a central angle of 180 degrees. The height of the first side wall 321 in the axial direction is lower than the height of the second side wall 322 in the axial direction of the cylindrical portion.

The valve device 1 includes a seal member 40. The sealing member 40 covers most of the valve seat member 30. A portion of the one surface 331 of the flange portion 33 that contacts a stepped surface 114, which will be described later, is exposed from the sealing member 40 without being covered by the sealing member 40. A portion of the other surface 332 of the flange portion 33, which is in contact with a wave washer 51 described later, is not covered with the sealing member 40 and is exposed from the sealing member 40.

The seal member 40 has a first covering portion 41, a first protruding portion 42, a second covering portion 43, a second protruding portion 44, and a third covering portion 45.

The first cover 41 covers the first side wall 321. Specifically, the first covering portion 41 covers the radially inner and outer ends of the first side wall portion 321 and the opposite end thereof on the flange portion 33 side.

The first protrusion 42 is provided on the valve chamber 11 side in the first side wall portion 321. That is, the first protruding portion 42 is provided at the end portion on the opposite side of the flange portion 33 side in the first covering portion 41. The first projecting portion 42 is a portion projecting outward in the radial direction of the flange portion 33 from the first covering portion 41. The first protrusion 42 corresponds to a valve member-side seal portion that closes a gap between the valve member main body portion 21 and the valve seat member 30 by coming into contact with the valve member main body portion 21.

The second covering portion 43 is a portion covering the second side wall portion 322. Specifically, the second covering portion 43 covers the radially inner and radially outer sides of the second side wall portion 322, the end portion on the opposite side of the flange portion 33 side, and the end surface of the second side wall portion 322 at the portion connected to the first side wall portion 321. As shown in fig. 8, the second covering portion 43 has sealing surfaces 46 and 47 at portions covering end surfaces of portions connected to the first side wall portion 321. The sealing surfaces 46, 47 are connected to the first projection 42.

The second protrusion 44 is provided on the valve chamber 11 side in the second side wall portion 322. That is, the second protruding portion 44 is provided at the end portion on the opposite side of the flange portion 33 side in the second covering portion 43. The second projecting portion 44 is a portion projecting from the second covering portion 43 inward in the radial direction of the flange portion 33. The second projection 44 is connected to the sealing surfaces 46, 47. The second protrusion 44 corresponds to a valve member-side seal portion that closes a gap between the valve member main body portion 21 and the valve seat member 30 by coming into contact with the valve member main body portion 21.

The third covering portion 45 is an annular portion that covers a part of the other surface 332 of the flange portion 33. A part of the other surface 332 is a portion of the other surface 332 that is radially inside the flange portion 33. The third covering portion 45 is accommodated in the accommodation space 14 and corresponds to an annular housing-side seal portion that blocks the flow of fluid between the valve seat member 30 and the accommodation space inner wall 104.

The sealing member 40 is composed of only a rubber material. In the present embodiment, synthetic rubber is used as the rubber material. However, natural rubber may also be used as the rubber material. The seal member 40 may be mainly made of a rubber material. That is, the seal member 40 may be made of a rubber material or other materials. The seal member 40 is integrally formed with the valve seat member 30. That is, the seal member 40 and the valve seat member 30 are formed as an integrally molded product in which the seal member 40 is integrally molded with the valve seat member 30. In the integral molding, the product is integrally molded at the same time as the joining of the components without using secondary adhesion or mechanical joining.

As shown in fig. 7, the third covering portion 45 is continuous without a joint with the first protruding portion 42 via a portion 411 of the first covering portion 41 that covers the inside in the radial direction of the first side wall portion 321 and a portion 412 of the first covering portion 41 that covers the end portion on the opposite side of the flange portion 33 side of the first side wall portion 321. Similarly, the third covering portion 45 is continuous with the second protruding portion 44 without a seam via a portion 431 of the second covering portion 43 that covers the inside of the second side wall portion 322 in the radial direction. Therefore, the portion 411 of the first covering portion 41 that covers the radially inner side of the first side wall portion 321 and the portion 412 that covers the end portion of the first side wall portion 321 correspond to a connecting portion that connects the valve member-side seal portion and the housing-side seal portion. The portion 431 of the second covering portion 43 covering the radially inner side of the second side wall portion 322 corresponds to a connecting portion connecting the valve-member-side seal portion and the housing-side seal portion.

As shown in fig. 6, the housing space inner wall 104 of the housing 10 includes a first wall surface 111, a second wall surface 112, a third wall surface 113, and a step surface 114. The first wall surface 111, the second wall surface 112, and the third wall surface 113 have the same shape as the inner surface of the side wall of the cylinder.

The first wall surface 111 is a portion of the inner wall 104 of the housing space closest to the valve chamber 11. The second wall surface 112 is a portion located farther from the valve chamber 11 than the first wall surface 111 in the housing space inner wall 104. The opening width of the second wall surface 112 is larger than the opening width of the first wall surface 111. The third wall surface 113 is a portion located farther from the valve chamber 11 than the second wall surface 112 in the housing space inner wall 104. The opening width of the third wall surface 113 is larger than the opening width of the second wall surface 112.

The level difference surface 114 is located between the first wall surface 111 and the second wall surface 112 in the housing space inner wall 104, and is a portion continuous with both the first wall surface 111 and the second wall surface 112. The level difference surface 114 is a surface generated by a difference in opening width between the first wall surface 111 and the second wall surface 112.

The seat member 30 is accommodated in the accommodation space 14 in a state where the one surface 331 of the flange portion 33 is in contact with the stepped surface 114. At this time, the step surface 114 and the one surface 331 of the flange portion 33 face each other in the direction along the axis CL of the flange portion 33. Therefore, the step surface 114 corresponds to an annular facing surface facing the flange 33 in a direction along the axis CL of the flange.

As shown in fig. 6, the valve device 1 includes a wave washer 51 and a fixing ring 52. The wave washer 51 and the fixing ring 52 are accommodated in the accommodating space 14 on the other surface 332 side of the flange portion 33.

As shown in fig. 9 and 10, the wave washer 51 is an annular plate having a wave shape. The wave washer 51 is a spring member for pressing the valve seat member 30 against the housing 10 by a reaction force generated at the time of elastic deformation. The spring constant of the wave washer 51 is larger than that of the third covering portion 45. The wave washer 51 is composed of only a metal material. The metal material may be stainless steel. The wave washer 51 may be mainly made of a metal material. That is, the wave washer 51 may be made of a metal material or other materials.

As shown in fig. 11, the wave washer 51 is provided on the outer peripheral side of the third covering portion 45 on the other surface 332 of the flange portion 33. The outer peripheral side means the same as the outer side in the radial direction of the flange portion 33. Fig. 11 is a front view of the valve seat member 30 when the valve seat member 30 is viewed from the flange portion 33 side in a state where the wave washer 51 is provided on the other surface 332 of the flange portion 33. The wave washer 51 is in contact with the other surface 332 of the flange portion 33. The wave washer 51 does not overlap the third covering portion 45 in the direction along the axis CL.

The fixing ring 52 is an annular plate. The thickness of the fixing ring 52 is larger than that of the wave washer 51. The radial plate width of the fixed ring 52 is larger than the radial plate width of the wave washer 51. The fixing ring 52 is composed of only a metal material. The metal material may be an aluminum alloy. The fixing ring 52 may be mainly made of a metal material. That is, the fixing ring 52 may be made of a metal material or other materials.

The fixing ring 52 is a fixing member for fixing the valve seat member 30 to the housing 10. The fixing ring 52 is press-fitted into the housing space inner wall 104 so as to press the flange portion 33 against the stepped surface 114 via the third covering portion 45 and the wave washer 51. Thereby, the valve seat member 30 is fixed to the housing 10. That is, the valve seat member 30 is clamped by the stepped surface 114 and the fixing ring 52 in the direction along the axis CL, and is fixed to the housing 10.

At this time, the wave washer 51 is sandwiched between the flange portion 33 and the fixed ring 52 in a state of being elastically deformed in the direction along the axis CL. Therefore, a reaction force against an external force that elastically deforms the wave washer 51 is generated in the wave washer 51. This reaction force is applied to the flange portion 33, and the flange portion 33 is pressed against the step surface 114.

The third covering portion 45 is sandwiched between the flange portion 33 and the fixing ring 52 in a compressed, elastically deformed state, so that the flange portion 33 and the fixing ring 52 are airtight. Therefore, the flange portion 33 and the fixed ring 52 are in an airtight state.

Further, since the fixing ring 52 is press-fitted to the housing space inner wall 104, the fixing ring 52 and the housing space inner wall 104 are in an airtight state. Further, the fixing ring 52 may be welded to the housing space inner wall 104, whereby the fixing ring 52 and the housing space inner wall 104 may be in an airtight state.

[ operation of valve device ]

Next, the operation of the valve device 1 will be described. As shown in fig. 3 and 4, the outer wall surface 211 of the valve member body 21 is moved between the opening 120 on the valve chamber 11 side of the upstream flow passage 12 and the opening 140 on the valve chamber 11 side of the housing space 14 by the rotation of the valve member 20.

Specifically, when the valve member 20 is rotated in the EGR passage opening direction, as shown in fig. 3, the valve member 20 is positioned at the opening 120 of the upstream side flow passage 12 to open the valve seat flow passage 31. That is, the valve member 20 opens the EGR passage 950 communicating with the housing space 14 to the maximum extent with respect to the valve chamber 11, and reduces the upstream side flow passage 12 to the minimum extent with respect to the valve chamber 11.

When the valve member 20 is rotated in the EGR passage blocking direction, as shown in fig. 4, the valve member 20 is positioned in the opening 140 of the housing space 14 to close the valve seat flow passage 31. That is, the valve member 20 fully closes the EGR passage 950 with respect to the valve chamber 11, and maximally opens the upstream flow passage 12 with respect to the valve chamber 11.

Here, a contact state between the seal member 40 and the valve member main body 21 when the valve member 20 closes the valve seat flow passage 31 will be described. When the valve member 20 rotates in the EGR passage blocking direction, as shown in fig. 6, the sealing surfaces 212 and 213 come into contact with the first protrusion 42 and the second protrusion 44, respectively. Further, when the valve member 20 rotates in the EGR passage blocking direction, as shown in fig. 12A and 12B, the first projecting portion 42 is pressed against the seal surface 212 and elastically deformed while being pushed down. Similarly, although not shown, the second protruding portion 44 is pressed against the sealing surface 213 and elastically deformed while being pushed down.

As shown in fig. 6, the connection sealing surfaces 214 and 215 contact the sealing surfaces 46 and 47, respectively, and compress the second covering portion 43. In fig. 6, the joining seal surface 215 and the seal surface 47 are shown, but the joining seal surface 214 and the seal surface 46 are not shown. Thereby, the exhaust passage 930 and the valve chamber 11 are blocked.

In this way, in the valve device 1, the valve member 20 rotates to open and close the EGR passage 950, and the opening degree of the EGR passage 950 with respect to the intake passage 920 can be increased or decreased. The gas flowing through the EGR passage 950 flows into the intake passage 920 due to the negative pressure of the intake passage 920.

Next, the effects of the present embodiment will be described.

(1) In the present embodiment, as shown in fig. 6, the third covering portion 45 is sandwiched between the flange portion 33 and the fixing ring 52.

Here, the valve device 1 of the present embodiment is compared with a valve device J1 of comparative example 1 shown in fig. 13. The valve device J1 of comparative example 1 corresponds to the valve device of patent document 1. The valve device J1 of comparative example 1 is different from the valve device 1 of the present embodiment in that it does not have the third covering portion 45. The other structure of the valve device J1 of comparative example 1 is substantially the same as that of the valve device 1 of the present embodiment.

In the valve device J1 of comparative example 1, only the wave washer 51 is sandwiched between the flange portion 33 and the fixed ring 52. Therefore, although not shown in fig. 13, a gap is generated between the flange portion 33 and the fixed ring 52 by the wave washer 51.

In the valve device J1 of comparative example 1, the one surface 331 of the flange portion 33 is in contact with the step surface 114. Thereby, sealing between the valve seat member 30 and the housing 10 is achieved.

However, when at least one of the stepped surface 114 and the one surface 331 of the flange portion 33 has low flatness, a gap is generated between the stepped surface 114 and the flange portion 33. Generally, in a synthetic resin member, a surface is not flattened. In a metal member, a surface is flattened. Therefore, when the valve seat member 30 is made of a synthetic resin material and the housing 10 is made of a metal material, the flatness of the one surface 331 of the flange portion 33 is lower than that of the stepped surface 114. Further, a gap may be generated between the flange portion 33 and the stepped surface 114 due to vibration during vehicle running or the like.

In these cases, when the valve member 20 closes the valve seat flow passage 31, the exhaust gas can pass through the gap between the flange portion 33 and the fixed ring 52 and the gap between the stepped surface 114 and the flange portion 33. Therefore, as shown by an arrow F1 in fig. 13, the exhaust gas flows between the valve seat member 30 and the housing 10. The exhaust gas leaks to the valve chamber 11. As described above, the inventors of the present application have found a problem that the valve device J1 of comparative example 1 has low sealability between the valve seat member 30 and the housing 10.

In contrast, according to the present embodiment, the third covering portion 45 can prevent the fluid from flowing between the flange portion 33 and the fixed ring 52. Further, the fixing ring 52 is fixed to the housing space inner wall 104 in a state where the fixing ring 52 and the housing space inner wall 104 are airtight. This can prevent the fluid from flowing between the valve seat member 30 and the housing 10. That is, the sealability between the valve seat member 30 and the housing 10 can be improved.

(2) In the present embodiment, the wave washer 51 is sandwiched between the flange portion 33 and the fixed ring 52 at a position on the outer peripheral side of the third covering portion 45. The spring constant of the wave washer 51 is larger than that of the third covering portion 45.

Here, in order to fix the valve seat member 30 to the housing 10, it is preferable that the flange portion 33 be pressed against the stepped surface 114 with a load of a certain degree or more.

However, unlike the present embodiment, if only the third covering portion 45 is sandwiched between the flange portion 33 and the fixing ring 52, the flange portion 33 cannot be pressed with a load of a certain degree or more due to deterioration of the third covering portion 45. In this case, the valve seat member 30 rotates, and the position of the valve seat member 30 relative to the housing 10 is shifted. The valve seat member 30 is displaced relative to the valve member main body portion 21. Therefore, when the valve member main body portion 21 is positioned to close the valve seat flow passage 31, the sealing between the valve member main body portion 21 and the valve seat member 30 is no longer possible. In this way, if only the third covering portion 45 is sandwiched between the flange portion 33 and the fixing ring 52, the fixing of the valve seat member 30 to the housing 10 can no longer be maintained.

In contrast, in the present embodiment, the flange portion 33 can be pressed against the stepped surface 114 with a load of a certain degree or more by utilizing the reaction force generated when the wave washer 51 is elastically deformed. Further, the wave washer 51 is made of a metal material. Generally, a metal material has less deterioration in elasticity than a rubber material. Therefore, the wave washer 51 has less deterioration in elasticity than the third covering portion 45. Thus, the flange portion 33 can be continuously pressed against the stepped surface 114 with a load of a certain degree or more, as compared with the case where only the third covering portion 45 is sandwiched between the flange portion 33 and the fixed ring 52. The fixation of the valve seat member 30 to the housing 10 can be maintained.

In addition, the metal material has less deterioration in elasticity than the rubber material, and means that when the same magnitude of compressive load is continuously applied for the same period of time in 2 materials, the reduction ratio of the reaction force to the compressive load occurring in the metal material is smaller than that of the rubber material. The comparison of the deterioration of elasticity was performed by a stress relaxation test of a rubber material specified in JIS K6263.

In the present embodiment, the wave washer 51 is disposed on the outer peripheral side of the third covering portion 45. However, the wave washer 51 may be disposed on the inner peripheral side of the third covering portion 45. The inner peripheral side means the same as the radially inner side of the flange portion 33.

(3) The moment M1 of the force of the first example of arrangement shown in fig. 14 is compared with the moment M2 of the force of the second example of arrangement shown in fig. 15.

Fig. 14 is a schematic diagram for explaining a moment M1 that acts around the contact end 114a on the flange portion 33 in the first configuration example. In the first arrangement example, unlike the present embodiment, the wave washer 51 is arranged on the inner peripheral side of the third covering portion 45. The wave washer 51 is disposed on the inner peripheral side of the contact end 114 a.

Fig. 15 is a schematic diagram for explaining a moment M2 acting around the contact end with respect to the flange portion in the second configuration example. In the second arrangement example, the wave washer 51 is arranged on the outer peripheral side of the third covering portion 45 as in the present embodiment. The third covering portion 45 is arranged on the inner peripheral side of the contact end 114 a.

Fig. 14 and 15 show only the third covering portion 45 of the seal member 40. As shown in fig. 14 and 15, the stepped surface 114 of the housing 10 has a contact end 114a as an inner peripheral end portion of a region contacting the flange portion 33.

The moments M1 and M2 are both expressed by the product of the force applied to the portion of the flange portion 33 on the inner peripheral side of the contact end 114a and the distance from the contact end 114a as the center to the portion of the flange portion 33 to which the force is applied. The force in the first arrangement example is a reaction force of the wave washer 51 generated by the elastic deformation. The force in the second arrangement example is a reaction force of the third covering portion 45 generated by elastic deformation. It is assumed that the distance in the first configuration example is the same as the distance in the second configuration example.

According to hooke's law, the reaction force of the spring generated by elastic deformation is represented by the product of the spring constant and the amount of deformation of the spring. When the amount of deformation of the spring is the same, the larger the spring constant, the larger the reaction force of the spring. The wave washer 51 used in the present embodiment has a larger spring constant than the third covering portion 45. Therefore, if the compression deformation amount of the wave washer 51 in the first arrangement example is compared with the compression deformation amount of the third covering portion 45 in the second arrangement example, the reaction force generated at the wave washer 51 is larger than the reaction force generated at the third covering portion 45. Thus, the moment M1 of the first example of arrangement is larger than the moment M2 of the second example of arrangement.

Thus, in the first arrangement example, as shown by the one-dot chain line in fig. 14, the valve seat member 30 is easily deformed. That is, the valve member 20 side end portion of the valve seat member 30 is easily expanded outward in the radial direction of the valve seat member 30. When the valve seat member 30 is deformed, the sealability between the valve member 20 and the valve seat member 30 is deteriorated. On the other hand, in the second arrangement example, the valve seat member 30 is less likely to be deformed than in the first arrangement example.

In the above description, the compression deformation amount of the wave washer 51 in the first arrangement example is compared with the compression deformation amount of the third covering portion 45 in the second arrangement example. However, even when the compression deformation amounts are different from each other, in the first arrangement example of fig. 14, when the reaction force generated by the wave washer 51 positioned on the inner peripheral side of the contact end 114a is larger than the reaction force generated by the third covering portion 45 positioned on the outer peripheral side of the wave washer 51, the deformation of the flange portion 33 is likely to occur.

Therefore, in the present embodiment, as shown in fig. 6, the wave washer 51 having a larger spring constant than the third covering portion 45 is disposed on the outer peripheral side of the third covering portion 45. As shown in fig. 15, the third covering portion 45 is arranged on the inner peripheral side of the contact end 114 a. The third covering portion 45 and the wave washer 51 are sandwiched between the flange portion 33 and the fixed ring 52 such that a reaction force generated in the wave washer 51 by the elastic deformation is smaller than a reaction force generated by the third covering portion 45.

Thus, as compared with the case where the wave washer 51 is disposed on the inner peripheral side of the third covering portion 45 and on the inner peripheral side of the contact end 114a, the moment acting on the flange portion 33 around the contact end 114a can be reduced. This can suppress deformation of the flange portion 33.

The "reaction force generated in the wave washer 51 by the elastic deformation" is obtained from the spring constant of the wave washer 51 and the deformation amount of the wave washer 51. The amount of deformation of the wave washer 51 is measured by comparing the shape of the wave washer 51 before the fixed ring 52 is removed with the shape of the wave washer 51 after the fixed ring 52 is removed. Similarly, the "reaction force generated in the third covering portion 45 by the elastic deformation" is obtained from the spring constant of the third covering portion 45 and the deformation amount of the third covering portion 45. The amount of deformation of the third covering portion 45 is measured by comparing the shape of the third covering portion 45 before the fixing ring 52 is removed with the shape of the third covering portion 45 after the fixing ring 52 is removed.

In the present embodiment, the entire third covering portion 45 is disposed on the inner peripheral side of the contact end 114 a. However, a part of the third covering portion 45 may be disposed on the inner peripheral side of the contact terminal 114a, and the other part of the third covering portion 45 may be disposed on the outer peripheral side of the contact terminal 114 a. In this way, at least a part of the third covering portion 45 may be arranged on the inner peripheral side of the contact end 114 a. This can provide the effect (3) described above.

(4) In the present embodiment, as shown in fig. 7, the third covering portion 45, the portions 411 and 412 of the first covering portion 41, the first protruding portion 42, the portion 431 of the second covering portion 43, and the second protruding portion 44 are simultaneously formed. Thus, they are constructed of the same material and are continuous without seams. By molding them at the same time, the third covering portion 45 and the valve seat member 30 are constituted as an integrally molded article in which the third covering portion 45 is integrally molded with respect to the valve seat member 30.

This can reduce the number of components compared to the case where the third covering portion 45 and the valve seat member 30 are separately configured.

(embodiment 2)

As shown in fig. 16 and 17, in the present embodiment, the first opening 34 is formed in the first side wall portion 321 and the flange portion 33 of the valve seat member 30. The second side wall portion 322 and the flange portion 33 of the valve seat member 30 are formed with a second opening portion 35.

The sealing member 40 has a first filling portion 48 filled in the first opening portion 34 and a second filling portion 49 filled in the second opening portion 35. The first protruding portion 42, the first covering portion 41, the first filling portion 48, and the third covering portion 45 are made of the same material and are continuous without a seam. Similarly, the second protruding portion 44, the second covering portion 43, the second filling portion 49, and the third covering portion 45 are made of the same material and are continuous without a seam.

In the present embodiment, the first covering portion 41, the first filling portion 48, the second covering portion 43, and the second filling portion 49 correspond to connection portions that connect the valve-side seal portion and the housing-side seal portion. The connecting portion connects the valve member-side seal portion and the housing-side seal portion through the opening portion including the first opening portion 34 and the second opening portion 35.

The first protruding portion 42, the first covering portion 41, the first filling portion 48, the second protruding portion 44, the second covering portion 43, the second filling portion 49, and the third covering portion 45 are simultaneously formed. Thus, the third covering portion 45 and the valve seat member 30 are constituted as an integrally molded article in which the third covering portion 45 is integrally molded with respect to the valve seat member 30. Therefore, the present embodiment can also obtain the effect (4) of embodiment 1.

The other structures of the valve device 1 are the same as those of embodiment 1. Therefore, the effects (1), (2) and (3) of embodiment 1 can be obtained by this embodiment as well.

(embodiment 3)

As shown in fig. 18, the valve device 1 of the present embodiment includes a seal ring 61 instead of the third covering portion 45 of embodiment 1.

The seal ring 61 is a member corresponding to the third covering portion 45 of embodiment 1. The seal ring 61 is not continuous with the seal member 40. The seal ring 61 is formed separately from the seal member 40 and the valve seat member 30. The seal ring 61 is annular and contacts the other surface 332 of the flange portion 33 over the entire circumferential direction of the flange portion 33. The seal ring 61 is composed of only synthetic rubber. The seal ring 61 may be mainly made of a rubber material. The seal ring 61 corresponds to an annular housing-side seal portion that blocks the flow of fluid between the valve seat member 30 and the housing space inner wall 104.

The other structures of the valve device 1 are the same as those of embodiment 1. Therefore, the same effects as those of embodiment 1 can be obtained by this embodiment as well.

(embodiment 4)

As shown in fig. 19, in the present embodiment, the valve device 1 does not include the wave washer 51 of embodiment 1. Only the third covering portion 45 is directly sandwiched by the flange portion 33 and the fixing ring 52. The third covering portion 45 covers the entire area of the other surface 332 of the flange portion 33 in the radial direction.

The other structures of the valve device 1 are the same as those of embodiment 1. Therefore, the effects (1) and (4) of embodiment 1 can be obtained by this embodiment as well.

In the present embodiment, it is preferable to use a material that is less likely to deteriorate as a material constituting the third covering portion 45. In the valve device 1 according to embodiment 3, only the seal ring 61 may be directly sandwiched between the flange portion 33 and the fixed ring 52, as in the present embodiment.

(other embodiments)

(1) In each of the above embodiments, when the valve member 20 closes the valve seat flow passage 31, the first protrusion 42 and the second protrusion 44 are pushed down by the sealing surfaces 212 and 213. However, the first and second projections 42, 44 may be compressed by the sealing surfaces 212, 213.

(2) In embodiment 3, the valve device 1 may not include the seal member 40. Specifically, as shown in fig. 20, the valve member 20 may be configured to close the valve seat flow passage 31 by directly contacting the valve seat member 30 with the valve member main body portion 21.

(3) In each of the above embodiments, the wave washer 51 is mainly made of a metal material. However, the wave washer 51 may be mainly made of a synthetic resin material. Generally, a synthetic resin material is less deteriorated than a rubber material. Therefore, in this case, the effects (2) and (3) of embodiment 1 can also be obtained.

(4) In each of the above embodiments, the wave washer 51 is used as the spring member. However, other shapes of spring members may be used. The spring constant of the spring member may be the same as that of the third covering portion 45 or the seal ring 61. Even in this case, the effects (2) and (3) of embodiment 1 can be obtained. The spring constant of the spring member may be smaller than the spring constant of the third covering portion 45 or the seal ring 61 as long as the flange portion 33 can be pressed against the stepped surface 114 with a load of a certain degree or more. In order to press the flange portion 33 against the stepped surface 114 with a load of a certain degree or more, the spring constant of the spring member is preferably equal to or more than the spring constant of the third covering portion 45 or the seal ring 61.

(5) In each of the above embodiments, the valve member main body portion 21 has a cylindrical shape. However, the valve member main body 21 may be spherical.

(6) In each of the above embodiments, the valve device 1 is applied to the engine system 90. However, the valve device 1 may be applied to other uses. The fluid flowing inside the valve device 1 is not limited to gas, and may be liquid.

(7) In the above embodiments, the housing 10, the fixing ring 52, the upper shaft 24, and the lower shaft 25 are made of a metal material. However, they may be made of a synthetic resin material.

(8) In each of the above embodiments, the valve member main body portion 21 and the valve seat member 30 are made of a synthetic resin material. However, they may be formed of a metal material.

(9) The present disclosure is not limited to the above-described embodiments, and can be modified as appropriate, and various modifications and modifications within an equivalent range are also included. The above embodiments are not independent of each other, and can be combined as appropriate except for the case where they are obviously not combinable. In the above embodiments, it goes without saying that elements constituting the embodiments are not necessarily essential, except for cases where they are specifically and explicitly indicated to be essential, cases where they are considered to be essential in principle, and the like. In the above embodiments, when numerical values such as the number, numerical value, amount, and range of the constituent elements of the embodiments are referred to, the number is not limited to a specific number unless it is specifically stated explicitly or clearly limited to a specific number in principle. In the above embodiments, when referring to the material, shape, positional relationship, and the like of the constituent elements and the like, the material, shape, positional relationship, and the like are not limited to those unless otherwise specifically indicated or limited to a specific material, shape, positional relationship, and the like in principle.

(conclusion)

According to the 1 st aspect shown in part or all of the embodiments, the valve device includes: a housing having a valve chamber inner wall forming a valve chamber, and a housing space inner wall forming a housing space communicating with the valve chamber; a valve member, which is housed in the valve chamber, and which has a cylindrical or spherical valve member main body; a valve seat member that is accommodated in the accommodation space and forms a valve seat flow path that is opened and closed by the valve member main body; an annular fixing member accommodated in the accommodation space and fixing the valve seat member to the housing; and an annular housing-side seal portion that is housed in the housing space and that prevents the flow of fluid between the valve seat member and the inner wall of the housing space. The valve seat member has: a cylinder part, wherein a valve seat flow path is formed inside the cylinder part; and a flange portion connected to an opposite side of the cylindrical portion to the valve chamber side and including a portion protruding in a ring shape to an outer side of the cylindrical portion than the cylindrical portion. The inner wall of the housing space includes an annular facing surface facing the flange in a direction along the axis of the flange. The valve seat member is fixed to the housing by sandwiching the flange portion between the facing surface and the fixing member in the direction along the axis. The fixing member is fixed to the inner wall of the housing space in an airtight state between the fixing member and the inner wall of the housing space. The case-side seal portion is mainly made of a rubber material and is sandwiched between the flange portion and the fixing member.

Further, according to the 2 nd aspect, the valve device includes the spring member that presses the valve seat member against the housing by a reaction force generated at the time of elastic deformation. The spring member is mainly made of a metal material or a synthetic resin material, and is sandwiched between the flange portion and the fixing member at a position on the inner circumferential side or the outer circumferential side of the case-side seal portion.

In order to fix the valve seat member to the housing, it is preferable that the flange portion is pressed against the opposite surface with a load of a certain degree or more. However, if only the case-side seal portion is interposed between the flange portion and the fixing member, the flange portion can no longer be pressed against the facing surface with a load of at least a certain degree due to deterioration of the case-side seal portion. In this case, the valve seat member rotates, and the position of the valve seat member relative to the housing is displaced. The position of the valve seat member is offset with respect to the valve member main body portion. Therefore, when the valve member main body portion is located at a position where the valve seat flow passage is closed, the sealing between the valve member main body portion and the valve seat member is no longer possible. As described above, if only the case-side seal portion is sandwiched between the flange portion and the fixed member, the fixation of the valve seat member to the case cannot be maintained.

According to claim 2, the spring member is sandwiched between the flange portion and the fixed member at a position on the inner circumferential side or the outer circumferential side of the housing-side seal portion. Therefore, the flange portion can be pressed against the facing surface with a load of a certain degree or more by utilizing the reaction force generated when the spring member is elastically deformed.

Further, the spring member is mainly made of a metal material or a synthetic resin material. Generally, a metal material and a synthetic resin material have less deterioration in elasticity than a rubber material. Therefore, the spring member is less deteriorated in elasticity than the case-side seal portion. As compared with the case where only the case-side seal portion is sandwiched between the flange portion and the fixed member, the flange portion can be continuously pressed against the opposing surface with a load of at least a certain degree, and the fixation of the valve seat member to the case can be maintained.

Further, according to the 3 rd aspect, the spring member is disposed on the outer peripheral side of the housing-side seal portion. The facing surface has a contact end serving as an inner peripheral end of a region in contact with the flange. At least a part of the housing-side sealing portion is disposed on the inner peripheral side of the contact end. The housing-side seal portion and the spring member are sandwiched between the flange portion and the fixed member so that a reaction force generated in the housing-side seal portion by elastic deformation is smaller than a reaction force generated in the spring member by elastic deformation.

This can suppress a force applied to a portion of the flange portion on the inner peripheral side of the contact end to a small amount. Therefore, the moment of the force acting around the contact end to the flange portion can be reduced. This can suppress deformation of the flange portion.

Further, according to the 4 th aspect, the case-side seal portion and the valve seat member are formed as an integrally molded product. This can reduce the number of components compared to a case where the case-side sealing portion and the valve seat member are separately formed.

Further, according to the 5 th aspect, the valve device includes: a valve member side seal portion provided on the valve chamber side in the cylindrical portion, and configured to close a gap between the valve member main body portion and the valve seat member by coming into contact with the valve member main body portion; and a connecting portion connecting the valve member-side sealing portion and the housing-side sealing portion. The valve member side seal portion, the housing side seal portion, and the coupling portion are made of the same material and are continuous without a seam.

Thereby, the valve member-side seal portion, the housing-side seal portion, and the coupling portion are simultaneously molded. In this way, when the valve device includes the valve member-side seal portion, the housing-side seal portion and the valve seat member can be integrally molded by simultaneously molding the valve member-side seal portion and the housing-side seal portion.