JP2021092251A - Valve device - Google Patents

Abstract

To provide a valve device which can suppress increase in a maximum flow rate of a fluid due to change with time of a seal protrusion part.SOLUTION: A valve device 1 includes: a housing 10 having a valve chamber 11 and a storage space 14; a valve member 20 stored in the valve chamber 11; and a valve seat member 30 and a fixing member 60 stored in the storage space 14. The valve seat member 30 includes a seal protrusion part 54 for coming into contact with the valve member 20 and closing a gap between the valve member 20 and the valve seat member 30 when a valve seat flow passage 31 is closed by the valve member 20. The seal protrusion part 54 protrudes toward the inside of the valve seat member 30. A flow passage cross-sectional area of an inside flow passage 61 of the fixing member 60 is smaller than a flow passage cross sectional area of the valve seat flow passage 31 at the position of the seal protrusion part 54. Then, the flow passage cross sectional area of the inside flow passage 61 is the minimum flow passage cross sectional area in a flow passage of exhaust air formed inside a storage space inner wall 104 when the valve seat flow passage 31 is fully opened.SELECTED DRAWING: Figure 3

Description

The present invention relates to a valve device.

Patent Document 1 discloses a valve device. This valve device includes a housing having a valve chamber and an accommodating space communicating with the valve chamber, a valve member accommodated in the valve chamber, and a valve seat member accommodated in the accommodating space. A valve seat flow path opened and closed by the valve member is formed inside the valve seat member. The valve seat member has a seal portion that comes into contact with the valve member and closes the gap between the valve member and the front seat flow path when the valve seat flow path is closed by the valve member. The seal portion includes a seal protrusion that protrudes into the valve seat flow path.

Japanese Unexamined Patent Publication No. 2019-52707

In the conventional valve device described above, the flow path cross-sectional area of the valve seat flow path at the position of the seal protrusion is the minimum flow path cross-sectional area in the flow path including the valve seat flow path formed in the accommodation space. Therefore, the flow rate of the fluid passing through the valve seat flow path when the valve seat flow path is fully opened (that is, the maximum flow rate of the fluid) is determined by the flow path cross-sectional area of the valve seat flow path at the position of the seal protrusion.

However, since the seal protrusion is mainly made of a rubber material, it is settled with time. When the seal protrusion is settled, the flow path width is widened and the minimum flow path cross-sectional area is increased. Therefore, the problem of increasing the maximum flow rate of the fluid has been found by the present inventor. In addition, "sag" is a permanent deformation that occurs during long-term use.

In view of the above points, it is an object of the present invention to provide a valve device capable of suppressing an increase in the maximum flow rate of a fluid due to a change with time of a seal protrusion.

According to the invention according to claim 1, in order to achieve the above object.
The valve device is
A housing (10) having a valve chamber wall (101) forming a valve chamber (11), an accommodation space inner wall (104) forming an accommodation space (14) communicating with the valve chamber, and a housing (10).
A valve seat member (30) that is accommodated in the accommodation space and forms a valve seat flow path (31) through which a fluid flows.
A valve member (20) housed in a valve chamber and having a tubular or spherical valve member main body (21) that opens and closes a valve seat flow path.
It is provided with a fixing member (60), which is accommodated on the side of the accommodation space farther from the valve chamber than the valve seat member and fixes the valve seat member to the housing.
The valve seat member includes a tubular portion (41) that forms a valve seat flow path on the inside, and a flange portion (41) that is connected to the side of the tubular portion that is distant from the valve chamber and that protrudes outward from the tubular portion in an annular shape. 42) and, which is provided on the valve chamber side of the tubular portion, when the valve seat flow path is blocked by the valve member main body, it comes into contact with the valve member main body and is between the valve member main body and the valve seat member. It has a seal part (52, 54) that closes the gap between the two.
The inner wall of the accommodation space includes an annular facing surface (113) facing the flange portion in a direction along the axis (CL) of the flange portion.
The fixing member is fixed to the housing in the direction along the axis with the flange portion sandwiched between itself and the facing surface.
The seal portion includes a seal protrusion (54) projecting into the valve seat flow path.
The fixing member is annular, and an inner flow path (61) communicating with the valve seat flow path is formed inside the fixing member.
The material constituting the fixing member is a material having a smaller amount of change in shape with time as compared with the material constituting the seal protrusion.
The flow path cross-sectional area of the inner flow path of the fixing member is smaller than the flow path cross-sectional area of the valve seat flow path at the position of the seal protrusion, and the fluid formed inside the inner wall of the accommodation space when the valve seat flow path is fully opened. It is the minimum flow path cross-sectional area in the flow path of.

According to this, the flow path cross-sectional area of the inner flow path of the fixing member is smaller than the flow path cross-sectional area of the valve seat flow path at the position of the seal protrusion. The flow path cross-sectional area of this inner flow path is the minimum flow path cross-sectional area of the exhaust flow path formed inside the inner wall of the accommodation space when the valve seat flow path is fully opened. Therefore, the maximum flow rate of exhaust gas is determined by the flow path cross-sectional area of the inner flow path of the fixing member.

Further, the material constituting the fixing member is a material having a smaller amount of change in shape with time as compared with the material constituting the seal protrusion. Therefore, the flow path cross-sectional area of the inner flow path changes with time less than the flow path cross-sectional area of the valve seat flow path at the position of the seal protrusion.

Therefore, according to this, it is possible to suppress an increase in the maximum flow rate of the exhaust gas due to a change with time of the seal protrusion.

The reference reference numerals in parentheses attached to each component or the like indicate an example of the correspondence between the component or the like and the specific component or the like described in the embodiment described later.

It is a schematic diagram of the engine system to which the valve device of 1st Embodiment is applied. It is an external view of the valve device of 1st Embodiment. FIG. 3 is a sectional view taken along line III-III in FIG. It is a cross-sectional view of a valve device with the same cross section as FIG. 3, and is a view in which the position of the valve member is different from that of FIG. It is a perspective view of the valve member provided in the valve device of 1st Embodiment. It is an enlarged view of the VI part in FIG. It is a perspective view of the valve seat member provided in the valve device of 1st Embodiment. It is an enlarged view of the part VIII in FIG. It is a figure which shows the relationship between the operating angle of the valve member in the valve device of 1st Embodiment, and the flow rate of the air and exhaust which flow out from a valve device. It is sectional drawing of a part of the valve device of the comparative example 1. FIG. It is sectional drawing of the valve device which changed the flow path width of the inner flow path of a fixing member with respect to the valve device of FIG. FIG. 11A is a diagram showing the relationship between the operating angle of the valve member in the valve device of FIG. 11A and the flow rates of the air and exhaust gas flowing out from the valve device. It is sectional drawing of the valve device which changed the flow path width of the inner flow path of a fixing member with respect to the valve device of FIG. FIG. 12A is a diagram showing the relationship between the operating angle of the valve member in the valve device of FIG. 12A and the flow rates of the air and exhaust gas flowing out from the valve device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each of the following embodiments, parts that are the same or equal to each other will be described with the same reference numerals.

(First Embodiment)
As shown in FIG. 1, the valve device 1 of the present embodiment is applied to an engine system 90 that generates a driving force by burning fuel.

[Engine system configuration]
First, the engine system 90 will be described. The engine system 90 includes an engine 91, an intake system 92, an exhaust system 93, a supercharger 94, an exhaust recirculation system 95, and the like. The engine 91 accommodates the piston 912 in the cylinder 911 to form a combustion chamber 910. The engine 91 is an internal combustion engine that burns fuel in a combustion chamber 910 inside the engine.

The intake system 92 supplies air to the engine 91 from the outside air. The intake system 92 includes an intake pipe 921, an intake manifold 922, an air cleaner 923, an intercooler 924, a throttle 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 guiding intake air to the combustion chamber 910, and forms an intake passage 920. One end of the intake pipe 921 is open to the outside air, and the other end is connected to the 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 structure that branches into the same number of passages as the number of cylinders 911. The air cleaner 923 removes foreign matter from the air taken in from the atmosphere. The intercooler 924 cools the intake air compressed and heated by the compressor 941 of the supercharger 94. The throttle 925 adjusts the intake amount of the engine 91. The throttle 925 is electrically connected to the electronic control unit 96. Hereinafter, the electronic control unit will be referred to as an ECU.

The exhaust system 93 discharges the exhaust gas discharged by the engine 91 to the outside air. 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 the 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 merge. The exhaust purification unit 933 is provided in the exhaust pipe 931. The exhaust gas purification unit 933 decomposes hydrocarbons contained in the exhaust gas and captures particulate matter.

The supercharger 94 uses the energy of the exhaust gas to compress the intake air in the intake pipe 921, and supercharges the pressurized intake air to the combustion chamber 910. The turbocharger 94 includes a compressor 941, a turbine 942, and a shaft 943. The compressor 941 is arranged between the air cleaner 923 and the intercooler 924 in the intake passage 920. The compressor 941 can compress the intake air. The turbine 942 is arranged between the exhaust manifold 932 and the exhaust purification unit 933 in the exhaust passage 930. The turbine 942 is rotationally driven by the energy of the exhaust gas. The shaft 943 connects the compressor 941 and the turbine 942. The compressor 941 and the turbine 942 rotate synchronously with the shaft 943.

The exhaust gas return system 95 returns the exhaust gas after passing through the turbine 942 to the intake passage 920 and supplies the exhaust gas to the combustion chamber 910 together with the air passing 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 and the upstream side of the compressor 941 of the intake pipe 921. The EGR pipe 951 forms an EGR passage 950 that recirculates the exhaust gas after passing through the turbine 942 to the air before compression by the compressor 941. The EGR cooler 952 is provided in the EGR tube 951. The EGR cooler 952 cools the gas passing through the EGR passage 950.

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

The ECU 96 is composed of a CPU as a calculation unit, a microcomputer having a RAM, a ROM, and the like as a storage unit, and the like. The ECU 96 controls the drive of the throttle 925 and the valve device 1 according to the drive status of the vehicle or device on which the engine system 90 is mounted and the operation content of the operator who operates the vehicle or device.

[Valve device configuration]
Next, the configuration of the valve device 1 will be described. The valve device 1 is a rotary valve in which the opening degree of the 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 FIGS. 2, 3 and 4, the valve device 1 includes a housing 10, a valve member 20, a valve seat member 30, and a fixing member 60. FIG. 4 shows the same cross section as FIG. 3 of the valve device 1. The position of the valve member 20 in FIG. 4 is different from the position of the valve member 20 in FIG.

The housing 10 forms a confluence of the intake passage 920 and the EGR passage 950. The housing 10 is formed so as to accommodate the valve member 20. The housing 10 is made of only a metal material. Examples of the metal material include aluminum alloys. The housing 10 may be mainly made of a metal material. That is, the housing 10 may be made of a metal material and another material.

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

The valve chamber 11 is formed so as to rotatably accommodate the valve member 20. The upstream side flow path 12 is formed so as to communicate with the valve chamber 11. The upstream flow path 12 communicates with the air cleaner 923. The downstream flow path 13 is formed so as to communicate with the valve chamber 11 separately from the upstream side flow path 12. 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 accommodation space 14 is formed so as to communicate with the valve chamber 11 separately from the upstream side flow path 12 and the downstream side flow path 13. The accommodation space 14 is formed so as to be able to accommodate the valve seat member 30. The accommodation 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 valve seat flow path 31 of the valve seat member 30. The valve member 20 is provided so as to be rotatable relative to the housing 10. The valve member 20 is driven by an electric motor (not shown). Here, regarding the rotation direction of the valve member 20, for convenience, the direction in which the valve member 20 rotates from the state of FIG. 3 to the state of FIG. 4 is referred to as an "EGR passage blocking direction". The direction of rotation 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 housed in the storage space 14. The valve seat member 30 is a member separate from the housing 10. The valve seat member 30 is a member that forms a valve seat flow path 31 through which exhaust gas flows. Since the accommodation space 14 communicates with the EGR passage 950, the valve seat flow path 31 communicates with the EGR passage 950.

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

The valve member main body 21 has a tubular shape. The outer wall surface 211 of the valve member main body 21 is formed so as to have the same shape as a part of the radial outer wall surface of the cylinder. The outer wall surface 211 has sealing surfaces 212, 213 and connecting sealing surfaces 214, 215.

The seal surfaces 212 and 213 are formed on 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 has a semi-cylindrical shape with a central angle of 180 degrees. The sealing surface 212 is formed so that the radius is larger than the radius 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 has a semi-cylindrical shape with a central angle of 180 degrees. The virtual cylindrical surface including the sealing surface 212 and the virtual cylindrical surface including the sealing surface 213 have a central axis coaxially. The central axis is orthogonal to the rotation axis of the valve member 20.

The connection seal surfaces 214 and 215 are formed so as to be orthogonal to the seal surfaces 212 and 213. The normals of the connection seal surfaces 214 and 215 can be orthogonal to the rotation axis of the valve member 20 when translated. The connection seal surface 214 is located on the upper arm 22 side of the locations where the seal surface 212 and the seal surface 213 are connected. The connection seal surface 215 is located on the lower arm 23 side of the points where the seal surface 212 and the seal surface 213 are connected.

The upper arm 22 and the lower arm 23 are portions formed in a substantially fan shape. The upper arm 22 is provided at one end of the valve member main body 21 in the axial direction. The lower arm 23 is provided at the other end of the valve member main body 21 in the axial direction. The valve member main 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, for example, 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 and 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 only a metal material such as stainless steel. The upper shaft 24 is provided on the upper arm 22. The upper shaft 24 extends in a direction away from the upper arm 22 with respect to the valve member main body 21. The lower shaft 25 is provided on the lower arm 23. The lower shaft 25 extends in a direction away from the lower arm 23 with respect to 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 FIGS. 6 and 7, the valve seat member 30 includes a valve seat main body member 40 and a valve seat seal member 50.

The valve seat main body member 40 has a tubular portion 41 and a flange portion 42. The tubular portion 41 forms a valve seat flow path 31 inside. The tubular portion 41 extends in a direction parallel to the axis CL, that is, in the axial direction. The flange portion 42 is connected to the tubular portion 41 on the side opposite to the valve chamber 11 side. The flange portion 42 projects outward from the tubular portion 41 in an annular shape. The axis CL is the center line of the tubular portion 41 and also the center line of the flange portion 42. The flange portion 42 has one surface 421 of the flange portion 42 located on one side in the axial direction and another surface 422 of the flange portion 42 located on the other side of the flange portion 42 in the axial direction.

As shown in FIG. 7, the tubular portion 41 has a first side wall portion 411 and a second side wall portion 412. The first side wall portion 411 and the second side wall portion 412 are formed so as to have the same shape as a part of the side wall portion of the cylinder. The first side wall portion 411 and the second side wall portion 412 are formed so that the central angle is 180 degrees. The height of the first side wall portion 411 in the axial direction is lower than the height of the second side wall portion 412 in the axial direction.

The valve seat body member 40 is made of only a synthetic resin material. The valve seat main body member 40 may be mainly made of a synthetic resin material. That is, the valve seat main body member 40 may be made of a synthetic resin material and another material. The synthetic resin material is a synthetic polymer compound other than synthetic fiber and synthetic rubber. Further, the valve seat main body member 40 may be made of only a metal material.

As shown in FIG. 6, the valve seat seal member 50 covers the portion of the valve seat main body member 40 on the valve chamber 11 side. Specifically, the valve seat seal member 50 covers the tubular portion 41, but does not cover the flange portion 42.

As shown in FIG. 7, the valve seat seal member 50 has a first covering portion 51, a first protruding portion 52, a second covering portion 53, and a second protruding portion 54.

The first covering portion 51 is a portion that covers the first side wall portion 411. Specifically, the first covering portion 51 covers the radial inner side, the radial outer side, and the end portion on the side opposite to the flange portion 42 side of the first side wall portion 411.

The first protruding portion 52 is provided on the valve chamber 11 side of the first side wall portion 411. That is, it is provided at the end of the first side wall portion 411 on the side opposite to the flange portion 42 side. The first protruding portion 52 is a portion having a shape protruding outward from the first covering portion 51 in the radial direction of the flange portion 42. The first protruding portion 52 is a part of a seal portion that closes the gap between the valve member main body 21 and the valve seat member 30 by coming into contact with the valve member main body 21.

The second covering portion 53 is a portion that covers the second side wall portion 412. Specifically, the second covering portion 53 includes the radial inner side of the second side wall portion 412, the radial outer side, the end portion on the side opposite to the flange portion 42 side, and the first side wall portion 411 of the second side wall portion 412. Cover the end face of the part to be connected with. As shown in FIG. 7, the second covering portion 53 has sealing surfaces 55 and 56 at a portion covering the end surface of the portion connected to the first side wall portion 411. The sealing surfaces 55 and 56 are connected to the first protruding portion 52.

The second protruding portion 54 is provided on the valve chamber 11 side of the second side wall portion 412. That is, the second protruding portion 54 is provided at the end portion of the second covering portion 53 on the side opposite to the flange portion 42 side. The second protruding portion 54 is a portion having a shape protruding inward in the radial direction of the flange portion 42 from the second covering portion 53. That is, the second protruding portion 54 is a seal protruding portion that protrudes into the valve seat flow path 31. The second protruding portion 54 is connected to the sealing surfaces 55 and 56. The second protruding portion 54 is a part of a seal portion that closes the gap between the valve member main body 21 and the valve seat member 30 by coming into contact with the valve member main body 21.

The valve seat seal member 50 is made of only a rubber material. In this embodiment, synthetic rubber is used as the rubber material. However, natural rubber may be used as the rubber material. The valve seat seal member 50 may be mainly made of a rubber material. That is, the valve seat seal member 50 may be made of a rubber material and another material.

The valve seat seal member 50 is integrally molded with the valve seat main body member 40 by insert molding. That is, the valve seat seal member 50 and the valve seat main body member 40 are configured as an integrally molded product in which the valve seat seal member 50 is integrally molded with the valve seat main body member 40. Integral molding is to integrally mold a product at the same time as joining members without using secondary bonding or mechanical joining.

As shown in FIG. 6, the accommodation space inner wall 104 of the housing 10 includes a first wall surface 111 in which the tubular portion 41 is arranged inside, a second wall surface 112 in which the fixing member 60 is arranged inside, and a stepped surface 113. including. The first wall surface 111 and the second wall surface 112 have the same shape as the inner surface of the side wall of the cylinder. The opening width of the second wall surface 112 is larger than the opening width of the first wall surface 111. The step surface 113 is located between the first wall surface 111 and the second wall surface 112 of the accommodation space inner wall 104. The step surface 113 is a surface that intersects (for example, is orthogonal to) the axial direction of the first wall surface 111 and the second wall surface 112.

The valve seat member 30 is accommodated in the accommodating space 14 in a state where one surface 421 of the flange portion 42 is in contact with the stepped surface 113. At this time, the stepped surface 113 and the one surface 421 of the flange portion 42 face each other in the direction along the axis CL of the flange portion 42. Therefore, the stepped surface 113 corresponds to an annular facing surface facing the flange portion 42 in the direction along the axis CL of the flange portion.

As shown in FIGS. 3 and 4, the fixing member 60 is accommodated on the side of the accommodating space 14 farther from the valve chamber 11 than the valve seat member 30. The fixing member 60 is a member that fixes the valve seat member 30 to the housing 10. As shown in FIG. 6, the fixing member 60 is press-fitted against the inner wall 104 of the accommodation space so as to press the flange portion 42 against the stepped surface 113. That is, the fixing member 60 is fixed to the housing 10 in a direction along the axis CL with the flange portion 42 sandwiched between itself and the stepped surface 113.

As shown in FIG. 3, the fixing member 60 is an annular plate, and an inner flow path 61 communicating with the valve seat flow path 31 is formed inside the fixing member 60. As shown in FIG. 6, when the positions of the inner end surface 62 of the fixing member 60 and the tip 54a of the second protruding portion 54 are compared at the same positions in the circumferential direction of the valve seat member 30, the inner end surface of the fixing member 60 is compared. Reference numeral 62 denotes a radial direction centered on the axis CL of the flange portion 42, which is at the same position as the tip 54a of the second protruding portion 54. Therefore, as shown in FIGS. 3 and 6, the flow path width D1 of the inner flow path 61 is the first of the valve seat flow path 31 when the second protrusion 54 is not in contact with the valve member main body 21. It is smaller than the flow path width D2 at the position of the two protrusions 54. As a result, the flow path cross-sectional area of the inner flow path 61 is smaller than the flow path cross-sectional area of the valve seat flow path 31 at the position of the second protrusion 54. The flow path cross-sectional area of the inner flow path 61 is the minimum flow path cross-sectional area of the exhaust flow path formed inside the accommodation space inner wall 104 when the valve seat flow path 31 is fully opened.

The fixing member 60 is made of only a metal material. Examples of the metal material include aluminum alloys. The metal material is a material in which the amount of change in shape with time is small as compared with the material constituting the valve seat seal member 50. The fixing member 60 may be made of a material other than a metal material as long as the amount of change in shape with time is smaller than that of the material constituting the valve seat seal member 50.

Since the fixing member 60 is press-fitted into the accommodation space inner wall 104, a part of the second wall surface 112 of the accommodation space inner wall 104 is deformed. Further, in the fixing member 60, the fixing member 60 may be fixed to the housing 10 by caulking in addition to press fitting. Further, the fixing member 60 may be fixed to the housing 10 by welding the fixing member 60 to the inner wall 104 of the accommodation space.

[Activation of valve device]
Next, the operation of the valve device 1 will be described. As shown in FIGS. 3 and 4, in the valve member 20, the outer wall surface 211 of the valve member main body 21 rotates to open the opening 120 on the valve chamber 11 side of the upstream flow path 12 and the opening on the valve chamber 11 side of the accommodation space 14. Go back and forth between 140.

Specifically, when the valve member 20 rotates in the EGR passage opening direction, the valve member 20 is located at the opening 120 of the upstream side flow path 12 and opens the valve seat flow path 31 as shown in FIG. That is, the valve member 20 narrows the upstream side flow path 12 to the minimum with respect to the valve chamber 11 while fully opening the valve seat flow path 31 with respect to the valve chamber 11.

Further, when the valve member 20 rotates in the EGR passage blocking direction, the valve member 20 is located at the opening 140 of the accommodation space 14 and closes the valve seat flow path 31 as shown in FIG. That is, the valve member 20 opens the upstream side flow path 12 to the maximum with respect to the valve chamber 11 while fully closing the valve seat flow path 31 with respect to the valve chamber 11.

Here, when the valve member 20 closes the valve seat flow path 31, the first protruding portion 52 and the second protruding portion 54 are pushed by the valve member main body portion 21, so that the first protruding portion 52 and the second protruding portion 52 and the second The protruding portion 54 is elastically deformed. Specifically, as shown in FIG. 8, the second protruding portion 54 is pushed by the seal surface 213 of the valve member main body portion 21 so that the second protruding portion 54 is in a collapsed state. Although not shown, the first protruding portion 52 is also pushed by the seal surface 212 of the valve member main body portion 21, so that the second protruding portion 54 is in a collapsed state. As a result, the space between the valve member 20 and the valve seat member 30 is sealed.

On the other hand, when the valve member 20 rotates in the EGR passage opening direction from the state where the valve member 20 closes the valve seat flow path 31, and the valve member 20 and the second protrusion 54 are in a non-contact state, the second The protrusion 54 returns to its original shape.

In this way, in the valve device 1, by rotating the valve member 20, the EGR passage 950 can be opened and closed, and the opening degree of the EGR passage 950 with respect to the intake passage 920 can be increased or decreased. According to the valve device 1, as shown in FIG. 9, the flow rates of the air and the exhaust gas flowing out from the valve device 1 can be adjusted according to the operating angle of the valve member 20. The exhaust 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 effect of this embodiment will be described.

As shown in FIG. 10, in the valve device J1 of Comparative Example 1, the inner end surface 62 of the fixing member 60 is outside the tip 54a of the second protruding portion 54 in the radial direction centered on the axis CL of the flange portion 42. Located in. The flow path width D1 of the inner flow path 61 is from the flow path width D2 of the valve seat flow path 31 at the position of the second protrusion 54 when the second protrusion 54 is not in contact with the valve member main body 21. Is also big. The flow path cross-sectional area of the valve seat flow path 31 at the position of the second protrusion 54 is the minimum flow path cross-sectional area in the exhaust flow path formed inside the inner wall 104 of the accommodation space when the valve seat flow path 31 is fully opened. Is. Therefore, when the valve seat flow path 31 is fully opened, the flow rate of the exhaust gas passing through the valve seat flow path 31 (that is, the maximum flow rate of the exhaust gas) is the flow path breakage of the valve seat flow path 31 at the position of the second protrusion 54. Determined by area.

However, since the second protruding portion 54 is made of a rubber material, sagging occurs due to aging. That is, the second protruding portion 54 is plastically deformed from the shape shown by the solid line in FIG. 10 to the shape when the valve seat flow path 31 shown by the broken line is closed. In this case, even when the valve seat flow path 31 is fully opened, the shape of the valve seat flow path 31 when closed is maintained. In this way, when the second protrusion 54 is settled, the flow path width of the valve seat flow path 31 at the position of the second protrusion 54 changes from the flow path width D2 shown in FIG. 10 to the flow path width D3. It expands and increases the minimum flow path cross-sectional area of the valve seat flow path 31 when the valve seat flow path 31 is fully opened. Therefore, the maximum flow rate of the exhaust gas increases as the cross-sectional area of the flow path increases.

On the other hand, in the valve device 1 of the present embodiment, the flow path cross-sectional area of the inner flow path 61 is smaller than the flow path cross-sectional area of the valve seat flow path 31 at the position of the second protrusion 54. The flow path cross-sectional area of the inner flow path 61 is the minimum flow path cross-sectional area of the exhaust flow path formed inside the accommodation space inner wall 104 when the valve seat flow path 31 is fully opened. The exhaust flow path formed inside the inner wall 104 of the accommodation space includes a valve seat flow path 31 and an inner flow path 61. Therefore, the maximum flow rate of the exhaust gas is determined by the flow path cross-sectional area of the inner flow path 61 of the fixing member 60.

Further, the material constituting the fixing member 60 is a metal material having a smaller amount of change in shape with time as compared with the material constituting the second protruding portion 54. Therefore, the flow path cross-sectional area of the inner flow path 61 changes with time less than the flow path cross-sectional area of the valve seat flow path 31 at the position of the second protrusion 54.

Therefore, according to the valve device 1 of the present embodiment, it is possible to suppress an increase in the maximum flow rate of the exhaust gas due to a change with time of the second protruding portion 54.

In the engine system 90 including the exhaust recirculation system 95 as in the present embodiment, the maximum flow rate of the exhaust recirculated to the engine is set to a maximum value in consideration of misfire of the engine. However, in the valve device J1 of Comparative Example 1, the maximum flow rate of the exhaust gas increases due to the change with time of the second protrusion 54. Therefore, if the second protrusion 54 changes with time, the engine 91 may misfire when the valve seat flow path 31 is fully opened. On the other hand, according to the valve device 1 of the present embodiment, such a problem can be avoided.

By the way, unlike the present embodiment, a part of the valve seat main body member 40 is projected inward, and the flow path cross-sectional area of the valve seat flow path 31 at that part is the inner wall 104 of the accommodation space when the valve seat flow path 31 is fully opened. It is conceivable to set it as the minimum cross-sectional area in the flow path of the exhaust gas formed inside the. However, in this case, the shape of the valve seat main body member 40 becomes complicated, and it is difficult to integrally mold the valve seat seal member 50 and the valve seat main body member 40 by insert molding, which is difficult to realize.

Further, unlike the present embodiment, a member separate from the valve seat member 30 and the fixing member 60 is used, and the flow path cross-sectional area of the flow path formed in the separate member is set to the valve seat flow path 31. It is conceivable to set the minimum cross-sectional area in the exhaust flow path formed inside the inner wall 104 of the accommodation space when fully opened. However, in this case, the number of parts of the entire valve device increases, which is not preferable.

On the other hand, according to the valve device 1 of the present embodiment, these problems can be avoided.

Further, according to the valve device 1 of the present embodiment, the maximum flow rate of exhaust gas is set by the flow path cross-sectional area of the inner flow path 61 of the fixing member 60. Therefore, as shown in FIGS. 11A and 12A, by setting the flow path cross-sectional area of the inner flow path 61 of the fixing member 60 to an arbitrary size, the maximum exhaust gas is set as shown in FIGS. 11B and 12B. The flow rate can be set to any size. That is, the maximum flow rate of the exhaust gas can be changed by changing the fixing member 60.

In both of the valve devices 1 shown in FIGS. 11A and 12A, the inner end surface 62 of the fixing member 60 is located at a position closer to the center than the second protruding portion 54 in the radial direction of the flange portion 42.

The flow path width D4 of the inner flow path 61 shown in FIG. 11A is smaller than the flow path width D1 of the inner flow path 61 shown in FIG. Therefore, as can be seen by comparing FIG. 11B and FIG. 9, the maximum flow rate of the exhaust gas in the valve device 1 shown in FIG. 11A is smaller than the maximum flow rate of the exhaust gas in the valve device 1 shown in FIG.

Further, the flow path width D5 of the inner flow path 61 shown in FIG. 12A is smaller than the flow path width D4 of the inner flow path 61 shown in FIG. 11A. Therefore, as can be seen by comparing FIG. 12B and FIG. 11B, the maximum flow rate of the exhaust gas in the valve device 1 shown in FIG. 12A is smaller than the maximum flow rate of the exhaust gas in the valve device 1 shown in FIG. 11A.

(Other embodiments)
(1) In each of the above embodiments, when the valve member 20 closes the valve seat flow path 31, the first protruding portion 52 and the second protruding portion 54 are tilted to the sealing surfaces 212 and 213. However, the first protrusion 52 and the second protrusion 54 may be compressed on the sealing surfaces 212 and 213.

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

(3) In each of the above embodiments, the valve device 1 is applied to the engine system 90. The fluid flowing through the valve seat flow path 31 is exhaust gas discharged from the engine 91 and supplied to the air intake side of the engine 91. However, the valve device 1 may be applied to other applications. That is, the fluid flowing through the valve seat flow path 31 may be a fluid other than the exhaust gas. Further, the fluid flowing through the valve seat flow path 31 is not limited to a gas, but may be a liquid.

(4) In each of the above embodiments, the housing 10, the upper shaft 24, and the lower shaft 25 are made of a metal material. However, these may be made of a synthetic resin material.

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

(6) The present invention is not limited to the above-described embodiment, and can be appropriately modified within the scope of claims, and includes various modifications and modifications within an equal range. Further, the above-described embodiments are not unrelated to each other, and can be appropriately combined unless the combination is clearly impossible. Further, in each of the above embodiments, it goes without saying that the elements constituting the embodiment are not necessarily essential except when it is clearly stated that they are essential and when they are clearly considered to be essential in principle. No. Further, in each of the above embodiments, when numerical values such as the number, numerical values, amounts, and ranges of the constituent elements of the embodiment are mentioned, when it is clearly stated that they are particularly essential, and in principle, the number is clearly limited to a specific number. It is not limited to the specific number except when it is done. Further, in each of the above embodiments, when referring to the material, shape, positional relationship, etc. of the constituent elements, etc., except when specifically specified or when the material, shape, positional relationship, etc. are limited to a specific material, shape, positional relationship, etc. in principle. , The material, shape, positional relationship, etc. are not limited.

10 Housing 20 Valve member 30 Valve seat member 41 Cylinder 42 Flange 52 First protrusion 54 Second protrusion 60 Fixing member 61 Inner flow path

Claims (2)

It ’s a valve device,
A housing (10) having a valve chamber wall (101) forming a valve chamber (11), an accommodation space inner wall (104) forming an accommodation space (14) communicating with the valve chamber, and a housing (10).
A valve seat member (30) that is accommodated in the accommodation space and forms a valve seat flow path (31) through which a fluid flows.
A valve member (20) housed in the valve chamber and having a tubular or spherical valve member main body (21) that opens and closes the valve seat flow path.
A fixing member (60), which is accommodated on a side of the accommodating space farther from the valve chamber than the valve seat member and fixes the valve seat member to the housing, is provided.
The valve seat member is connected to a tubular portion (41) that forms the valve seat flow path on the inside and a side of the tubular portion that is distant from the valve chamber, and is annular to the outer side of the tubular portion than the tubular portion. A flange portion (42) protruding from the shaft and a flange portion (42) provided on the valve chamber side of the tubular portion, which comes into contact with the valve member main body when the valve seat flow path is blocked by the valve member main body. It has a seal portion (52, 54) that closes a gap between the valve member main body portion and the valve seat member.
The inner wall of the accommodation space includes an annular facing surface (113) facing the flange portion in a direction along the axis (CL) of the flange portion.
The fixing member is fixed to the housing in a direction along the axis with the flange portion sandwiched between itself and the facing surface.
The seal portion includes a seal protrusion (54) projecting into the valve seat flow path.
The fixing member is annular, and an inner flow path (61) communicating with the valve seat flow path is formed inside the fixing member.
The material constituting the fixing member is a material having a smaller amount of change in shape with time as compared with the material constituting the seal protrusion.
The flow path cross-sectional area of the inner flow path of the fixing member is smaller than the flow path cross-sectional area of the valve seat flow path at the position of the seal protrusion, and when the valve seat flow path is fully opened, the inner wall of the accommodation space A valve device that is the smallest flow path cross-sectional area of the fluid flow path formed inside. The valve device according to claim 1, wherein the fluid is exhaust gas discharged from the internal combustion engine and supplied to the air intake side of the internal combustion engine.

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