JP7548892B2 - Valve mechanism - Google Patents

Description

This disclosure relates to a valve device that is installed in a pipe through which a fluid flows.

In recent years, vehicles have come to require a high level of quietness. For this reason, efforts are being made to reduce the airflow noise generated by valve devices installed in exhaust gas piping. Patent Document 1 discloses a configuration in which a low arc-shaped barrier member is placed on the inner wall surface of the piping to suppress the high-speed airflow that occurs when the valve body opens slightly.

Japanese Patent Application Publication No. 11-13500

Further investigation into the cause of airflow noise in the valve device revealed that airflow noise occurs behind the valve disc when the valve disc is opened to a certain extent.
In one aspect of the present disclosure, it is desirable to reduce noise generated by the valve arrangement.

One aspect of the present disclosure is a valve device disposed in a pipe through which a fluid flows, comprising a rotating shaft, a valve body, and a guide portion. The valve body is configured to be rotatably displaceable about the rotating shaft between a first position where the angle between the valve body and a plane perpendicular to the central axis of the pipe is relatively small, and a second position where the angle is relatively large. The guide portion guides a portion of the fluid flowing from upstream in a predetermined direction downstream of the valve body located within a predetermined range between the first position and the second position.

With this configuration, when the valve disc is located within a specified range, the fluid is more likely to flow into the space downstream of the valve disc. This makes it possible to prevent vortexes from being generated in the fluid in the space downstream of the valve disc. This makes it possible to reduce noise caused by vortexes generated by the placement of the valve device.

In the valve device described above, the guide portion may have an inclined surface that is inclined so as to approach the central axis as it approaches the downstream side. With this configuration, the guide portion can smoothly change the flow direction of the fluid. This makes it possible to suppress noise generated by the guide portion and the fluid, and suppress large pressure losses caused by the guide portion.

In the above-described valve device, the downstream surface, which faces downstream when the valve body is in the first position, may have a bent portion. The bent portion may be a portion that is bent such that the angle between the surface of the downstream surface downstream of the bent portion and the central axis is greater than the angle between the surface of the downstream surface upstream of the bent portion and the central axis. When the valve body has the above-described bent portion, vortices are likely to be generated when the fluid passes near the bent portion. However, with the above-described configuration, the generation of vortices can be suppressed, and therefore the generation of noise due to the bent portion can be suppressed.

In the valve device described above, the guide section may be configured to direct the fluid flowing downstream in the space on the piping side of the bend toward the downstream surface when the valve body is within a predetermined range. With this configuration, the fluid flowing along the axial direction of the piping, that is, the fluid flowing smoothly, passing through the piping side of the bend, can be directed toward the downstream surface of the bend. This makes it possible to increase the amount of fluid flowing toward the space where vortices are generated, and effectively suppress the generation of vortices.

In the valve device described above, the guiding portion may regulate the range of rotational displacement of the valve body. With this configuration, since the guiding portion regulates the range of rotational displacement of the valve body, it is possible to reduce the number of stoppers having a similar function, or to eliminate the stoppers. As a result, the configuration of the valve device can be simplified. In addition, it is possible to suppress noise caused by stoppers that are not guiding portions.

In the valve device described above, the guide portion may be a plate-shaped member extending in the longitudinal direction of the rotating shaft. With this configuration, the guide portion is widely disposed inside the piping, so that the direction of the fluid flow can be changed over a wide range, and the generation of vortexes can be effectively suppressed.

In the valve device described above, the rotating shaft may be disposed at a radial distance from the central axis of the pipe. With this configuration, the range in which the force that moves the valve body toward the open position when pressed by the fluid is widened. Therefore, when the valve body is pressed by the fluid, a rotational force that moves from the first position to the second position can be suitably generated.

FIG. 2 is a cross-sectional view of the valve device according to the first embodiment. Figures 2A-2D are cross-sectional views of the valve device of the first embodiment, with Figure 2A being in the closed position, Figure 2B being in the state where the valve disc has been rotated 30°, Figure 2C being in the state where the valve disc has been rotated 60°, and Figure 2D being in the open position. Figures 2E-2H are views of the valve device of the first embodiment as seen from the upstream side, and Figures 2E-2H correspond to Figures 2A-2D, respectively. FIG. 3A is a diagram explaining the exhaust gas flow through a valve device of a comparative example having no guide portion, FIG. 3B is a diagram explaining the characteristics of the bent portion, and FIG. 3C is a diagram explaining the exhaust gas flow through the valve device of the first embodiment. 4A and 4B are cross-sectional views showing the valve device of the second embodiment, and FIGS. 4C and 4D are views showing the valve device of the second embodiment as viewed from the upstream side. 5A and 5B are side views showing modified examples of the valve device. 6A and 6B are views of a modified valve device as viewed from the upstream side. FIG. 11 is a side view showing a modified example of the valve device. 8A and 8B are cross-sectional views showing a modified example of the valve device, and FIGS. 8C and 8D are views showing the modified example of the valve device as viewed from the upstream side. 9A and 9B are cross-sectional views showing a modified example of the valve device, and FIGS. 9C and 9D are views showing the modified example of the valve device as viewed from the upstream side.

Embodiments of the present disclosure will be described below with reference to the drawings. Note that the embodiments of the present disclosure are not limited to the following embodiments, and may take various forms as long as they fall within the technical scope of the present disclosure.

[1. First embodiment]
[1-1. Overall configuration]
As shown in FIG. 1 and FIG. 2A-2H, the valve device 1 of the first embodiment is a valve device disposed in a pipe 3 through which a fluid flows. In this embodiment, the pipe 3 is used as an exhaust pipe through which exhaust gas from a vehicle engine flows. The valve device 1 may be disposed at any position in the exhaust pipe, and may be disposed, for example, in an inner pipe of a muffler mounted in a flow path of exhaust gas of a vehicle. In the following, the description will be given using exhaust gas as an example of a fluid. As an example, the pipe 3 is a cylindrical member extending in a substantially straight line. Hereinafter, a line passing through the approximate center of a cross section of the pipe 3 taken along a plane perpendicular to the flow direction of the exhaust gas is referred to as a central axis 3a. The valve device 1 is configured to adjust the opening degree of the flow path formed by the pipe 3, and includes a rotating shaft 11, an upstream wall 13, a support 15, an urging portion 17, and a guide portion 19. In addition, the upstream wall 13 and the support 15 form a valve body 21.

The rotating shaft 11 is a rod-shaped member fixed to the pipe 3, and serves as the center of rotation of the valve body 21. The rotating shaft 11 is arranged so that its length is perpendicular to the flow direction of the exhaust gas in the pipe 3 (the direction of the central axis 3a). As shown in FIG. 1, the rotating shaft 11 is arranged at a radial distance from the central axis 3a of the pipe 3. The rotating shaft 11 is also arranged so as to penetrate the wall surface of the pipe 3, for example, as shown in FIG. 2H. The specific configuration of the rotating shaft 11 is not particularly limited as long as the valve body 21 is configured to be rotatably displaced around the rotating shaft 11.

The upstream wall 13 is a member that adjusts the opening of the flow path inside the pipe 3, and is a substantially disk-shaped member as shown in Fig. 2E-2H. The upstream wall 13 is a wall member that forms the upstream surface of the valve body 21 in the direction in which the exhaust gas flows. The surface of the upstream wall 13 that the exhaust gas hits is a flat surface. The upstream wall 13 is provided so as to be rotatable around the rotation shaft 11. The rotational operation of the upstream wall 13 will be explained using Fig. 2A-2H. Fig. 2A-2D is a cross-sectional view taken along a plane that passes through the central axis 3a of the pipe 3 and is perpendicular to the rotation shaft 11. Fig. 2E-2H is a view of the valve device 1 as seen from the upstream side of the pipe 3.

Figure 2A shows the valve body 21 in the closed position. The closed position is a position where the angle Θ between the valve body 21 and a plane S perpendicular to the central axis 3a is relatively small. The angle of the valve body 21 may be based on the main surface of the upstream wall 13. In this case, the angle between the upstream wall 13 and the plane S is the angle Θ. The main surface of the upstream wall 13 here may be the surface of the upstream wall 13 when the upstream wall 13 is considered to be a substantially flat surface. The angle Θ may also be specified by considering the entire valve body 21 as a single plane. The angle Θ is a value that indicates the approximate inclination state of the valve body 21.

When the valve body 21 is in the closed position, the angle Θ is 0°. The closed position is a position where the degree of blockage of the pipe 3 by the valve body 21 is relatively large. The degree of blockage here indicates the degree of difficulty in flowing the exhaust gas. The closed position in this embodiment is a position where the exhaust gas flows most poorly within the range in which the valve body 21 can be rotated and displaced. When the valve body 21 is in the closed position shown in FIG. 2A, the flow path is almost blocked by the upstream wall 13, as shown in FIG. 2E. The closed position described above corresponds to the first position.

Figure 2B shows the case where the valve body 21 is rotated and tilted, and the angle Θ becomes 30°. When the valve body 21 is tilted, as shown in Figure 2F, the space 5 through which the exhaust gas can move in the flow path gradually becomes larger, and the exhaust gas flows more easily than in the closed position.

Figure 2C shows the case where the valve body 21 has rotated and tilted, and the angle Θ is 60°. In this tilted state, as shown in Figure 2G, the space 5 is larger than when the angle Θ is 30°, and the exhaust gas flows more smoothly. In addition, at this time, the induction section 19 can be seen from the upstream side. In other words, the exhaust gas flowing along the length of the pipe 3 is more likely to hit the induction section 19.

Figure 2D shows the valve body 21 in the open position. The open position is a position where the angle Θ is relatively large. In Figure 2D, the angle Θ is 90°. The open position is a position where the degree of obstruction described above is relatively small. In this tilted state, as shown in Figure 2H, the space 5 is the largest, i.e., the opening degree is the largest, and exhaust gas passes through the valve device 1 most smoothly. The open position described above corresponds to the second position.

The valve body 21 is rotatably displaceable between a closed position and an open position.
As shown in FIGS. 1 and 2A, the upstream wall 13 is disposed at a position upstream of the rotary shaft 11 in the fluid flow direction when the valve body 21 is in the above-mentioned closed position.

In the following description, the direction in which the valve body 21 rotates from the open position to the closed position is referred to as the closing direction, and the direction in which the valve body 21 rotates from the closed position to the open position is referred to as the opening direction. As the valve body 21 rotates toward the closed position, the opening degree of the valve device 1 decreases and the degree of obstruction increases. In the following description, upstream and downstream refer to the upstream and downstream directions of the exhaust gas flow.

The support 15 is a container-shaped member that is fixed to the downstream side of the upstream wall 13 in the closed position. That is, the support 15 constitutes a downstream surface 15a that faces downstream when the valve body 21 is in the closed position. The downstream surface 15a has a bent portion 15b that protrudes downstream in the state shown in FIG. 1. The specific configuration of the bent portion 15b will be described later.

The rotary shaft 11 is fixed to the support 15. The upstream wall 13 is attached to the rotary shaft 11 via the support 15.
The biasing portion 17 biases the valve body 21 so that the valve body 21 moves toward the closed position. The biasing portion 17 is a spring component that biases the valve body 21 by elastic force. The biasing portion 17 is disposed outside the pipe 3, with one end connected to a side surface of the pipe 3 and the other end connected to the rotating shaft 11. The biasing portion 17 applies a rotational force to the rotating shaft 11 so that the valve body 21 moves toward the closed position.

The guide portion 19 is fixed to the pipe 3 downstream of the rotating shaft 11 and is a plate-shaped member that extends along the length of the rotating shaft 11. The guide portion 19 is inclined so as to approach the imaginary plane 11a shown in FIG. 1 as it approaches the downstream. The imaginary plane 11a here is a plane that extends to the position where the center of the rotating shaft 11 is located when the pipe 3 is viewed from the upstream side.

The major part of the induction section 19, excluding the ends, is disposed at a distance from the inner wall surface of the pipe 3. Therefore, exhaust gas can pass through both the space between the induction section 19 and the valve body 21, and the space on the opposite side of the induction section 19 from the side on which the valve body 21 is located (the space between the induction section 19 and the inner surface of the pipe 3).

The guiding portion 19 also regulates the range of rotational displacement of the valve body 21. As shown in FIG. 2A, the guiding portion 19 abuts against the support 15 of the valve body 21 when it is in the closed position, preventing it from rotating further in the closing direction. As shown in FIG. 2D, the guiding portion 19 abuts against the support 15 of the valve body 21 when it is in the open position, preventing it from rotating further in the opening direction.

[1-2. Exhaust gas flow control by induction section]
The induction section 19 has a function of controlling the flow of exhaust gas. However, for example, when the valve body 21 is at the angle of FIG. 2A, almost no exhaust gas flows, and when the valve body 21 is at the angle of FIG. 2D, there is no gap between the induction section 19 and the support 15, and exhaust gas does not flow through the gap, so in such cases, the function described below is not exerted. The induction section 19 exerts the function described below when the valve body 21 is located in a predetermined range between the closed position and the open position. The predetermined range is a range of rotation angles of the valve body 21 in which exhaust gas flowing from upstream abuts against the induction section 19 as a result of the valve body 21 being rotated and displaced in the open direction from the closed position, and exhaust gas flows between the induction section 19 and the valve body 21. In the following description, a case where the angle Θ of the valve body 21 is 60° will be described. To confirm, the angle Θ at which the function of the induction section 19 described later is exerted is not limited to 60°, and the function of the induction section 19 is exerted in a specific angle range including 60°.

Figure 3A shows the flow of exhaust gas when the induction section 19 is not provided as a comparative example. In the following description, the radial directions of the pipe 3 that are perpendicular to the longitudinal direction of the rotating shaft 11 are referred to as the first and second directions. The first direction is the direction in which the upstream end 21a is located when the valve body 21 is in the closed position, assuming that the end located upstream when the valve body 21 is in the open position is the upstream end 21a. The second direction is the direction opposite to the first direction.

As shown in FIG. 3A, when the valve body 21 rotates from the closed position to the open position, the exhaust gas flows in two separate directions, one in a first direction and the other in a second direction, centered around the valve body 21. When the exhaust gas passes next to the valve body 21, the flow path is narrower due to the valve body 21 than on the upstream side, so the flow rate of the exhaust gas increases. On the other hand, in the space immediately downstream of the valve body 21, the flow rate of the exhaust gas decreases. As a result of the exhaust gas flowing in this way, a vortex is generated in the space downstream of the valve body 21. This vortex is the cause of the airflow noise.

The bent portion 15b is a bent portion such that the angle between the downstream surface 15a and the central axis 3a increases as the downstream surface 15a moves toward the downstream side in the rotational position of the valve body 21 shown in FIG. 3A. In other words, as shown in FIG. 3B, the angle Θ2 between the surface 15d downstream of the bent portion 15b on the downstream surface 15a and the central axis 3a is greater than the angle Θ1 between the surface 15c upstream of the bent portion 15b on the downstream surface 15a and the central axis 3a. With this shape of the valve body 21, the flow path suddenly widens when passing by the bent portion 15b, making it easier for the exhaust gas to separate from the valve body 21 and making the generation of vortices more noticeable.

Figure 3C shows the valve device 1 of the first embodiment equipped with the guide portion 19. The guide portion 19 has an inclined surface 19a that is inclined so as to approach the central axis 3a as it approaches downstream. The guide portion 19 guides a portion of the exhaust gas to the downstream surface 15d of the downstream surface 15a of the valve body 21. As a result, the exhaust gas is prevented from separating from the valve body 21, and more exhaust gas flows into the space downstream of the valve body 21, thereby preventing the generation of vortexes.

The imaginary plane 15e shown in FIG. 3C is a plane that extends to the position where the bent portion 15b exists when the pipe 3 is viewed from the upstream side. At least a part of the inclined surface 19a of the guide portion 19 is disposed on the pipe 3 side of the bent portion 15b. As a result, the guide portion 19 directs the exhaust gas flowing downstream in the space on the pipe 3 side of the bent portion 15b to the downstream surface of the valve body 21. The side of the pipe 3 here refers to the side where the wall surface of the pipe 3 exists, located in the direction in which the bent portion 15b (downstream surface 15a) faces, with respect to the radial direction of the pipe 3.

[1-3. Rotation of the valve disc]
The biasing portion 17 is in a state where it is pulled longer than its natural length regardless of the rotation angle of the valve body 21, and generates a restoring force that contracts the spring component. When the valve body 21 is in the closed position, the extension of the biasing portion 17 is minimal, and the restoring force is minimal. Furthermore, as the valve body 21 approaches the open position, the extension of the biasing portion 17 increases, and the restoring force increases. Therefore, the restoring force of the biasing portion 17 generates a torque that rotates the valve body 21 toward the closed position (in other words, in the closing direction). Furthermore, the valve body 21 rotates in the opening direction due to the exhaust gas flowing through the piping 3.

As described above, the rotating shaft 11 is disposed at a position radially away from the central axis 3a. Therefore, when the upstream wall 13 is projected onto the above-mentioned plane S, the area on the upstream end 21a side is smaller. As a result, the rotational force from the exhaust gas is received more on the side opposite the upstream end 21a, and the valve body 21 as a whole receives a rotational force in the opening direction. When the rotational force is greater than the force of the biasing portion 17 in the closing direction, the valve body 21 opens in the opening direction.

[1-4. Effects]
(1a) In the valve device 1, the guide portion 19 is configured to guide a portion of the exhaust gas to the downstream surface 15d of the downstream face 15a of the valve body 21 located in a predetermined range between the closed position and the open position. Therefore, the guide portion 19 makes it easier for the exhaust gas to flow into the space along the downstream face of the valve body 21 (particularly the surface 15d downstream of the bent portion 15b). This makes it possible to suppress the generation of a vortex as shown in FIG. 3A, and to reduce noise caused by the vortex.

(1b) In the valve device 1, the induction section 19 has an inclined surface 19a that is inclined so as to approach the central axis 3a as it approaches the downstream side. This inclined surface 19a allows the flow direction of the exhaust gas to be smoothly changed, so that the induction section 19 can be prevented from generating noise or causing a large pressure loss.

(1c) In the valve device 1, the downstream surface 15a of the valve body 21 has a bent portion 15b. When the valve body 21 is located within a predetermined range, the guide portion 19 directs the flow direction of the exhaust gas flowing downstream in the space on the pipe 3 side from the bent portion 15b to the downstream surface 15a. Because the valve body 21 has the bent portion 15b, vortices are likely to occur in the space downstream of the bent portion 15b. However, because the guide portion 19 directs the exhaust gas flowing smoothly in the space on the pipe 3 side from the bent portion 15b to the downstream surface of the bent portion 15b, the amount of exhaust gas flowing toward the downstream side of the valve body 21 can be increased, and the generation of vortices can be effectively suppressed.

(1d) In the valve device 1, the induction section 19 functions as a stopper that restricts the range of rotational displacement of the valve body 21. This eliminates the need to provide a stopper separate from the induction section 19, simplifying the configuration of the valve device 1. In addition, a stopper other than the induction section 19 can suppress noise caused by exhaust gas.

(1e) In the valve device 1, the induction section 19 is a plate-shaped member that extends in the longitudinal direction of the rotating shaft 11. With this configuration, the induction section 19 is widely disposed inside the pipe 3, so that the flow direction of the exhaust gas can be changed over a wide range, and the generation of vortexes can be effectively suppressed.

(1f) In the valve device 1, the rotating shaft 11 is disposed at a radial distance from the central axis 3a. Therefore, when the valve body 21 is pressed by exhaust gas, a rotational force can be suitably generated that moves from the closed position to the open position.

[2. Second embodiment]
Since the second embodiment has a basic configuration similar to that of the first embodiment, a description of the common configuration will be omitted and the description will focus on the differences. Note that the same reference numerals as those in the first embodiment indicate the same configuration, and the preceding description will be referred to.

In the valve device 1 of the first embodiment, a configuration in which the induction part 19 is fixed to the pipe 3 is exemplified. On the other hand, in the valve device 101 of the second embodiment shown in Figures 4A-4D, the induction part 119 is different in that it is fixed to the rotating shaft 111.

The induction section 119 has a main body section 119a and a pair of connecting sections 119b. 119The main body section 119a is a plate-shaped member extending along the length of the rotating shaft 111 and is disposed at a distance from the inner wall surface of the pipe 3. Therefore, it functions in the same way as the induction section 19 of the first embodiment. The pair of connecting sections 119b extend from the rotating shaft 111 and connect both longitudinal ends of the main body section 119a to the rotating shaft 111.

The valve device 101 configured in this manner performs the same function as the valve device 1. In addition, since the guide portion 119 is provided on the rotating shaft 111, the work of fixing the guide portion 119 to the piping 3 can be eliminated. The rotating shaft 111 is fixed to the piping 3 so that the guide portion 119 does not displace even when the valve body 21 rotates. The specific configuration of the biasing portion for rotating the valve body 21 is not particularly limited. For example, it may be a spring component with one end connected to the valve body 21 and the other end connected to the rotating shaft 111.

3. Other embodiments
Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is in no way limited to the above-described embodiments, and can take various forms as long as it falls within the technical scope of the present disclosure.

(3a) The specific configuration of the guide portion of the present disclosure is not particularly limited, as long as it is configured to guide the flow direction of a portion of the fluid flowing from upstream to the downstream surface of the valve body located within a predetermined range.

For example, in the first and second embodiments described above, a configuration having a flat plate-shaped member as the guide portion is exemplified. However, the guide portion may be curved in the width direction of the plate. For example, as in the guide portion 201 shown in FIG. 5A, the guide portion may be curved so that the center in the width direction is toward the valve body 211, or as in the guide portion 203 shown in FIG. 5B, the guide portion may be curved so that the center in the width direction is away from the valve body 211.

In the above first and second embodiments, a configuration is exemplified in which the guide portion has a plate-shaped member that extends linearly in the longitudinal direction of the rotating shaft. However, the guide portion may be curved in the longitudinal direction of the plate. For example, as in guide portion 301 shown in FIG. 6A, the guide portion may be curved so that the center in the longitudinal direction is toward valve body 311, or as in guide portion 303 shown in FIG. 6B, the guide portion may be curved so that the center in the longitudinal direction is away from valve body 311. Also, for example, the guide portion may be short in the longitudinal direction of the rotating shaft.

In the first and second embodiments, a configuration including one member as the guide portion is exemplified. However, as shown in FIG. 7, the valve device 401 may include multiple guide portions 411, 413. The multiple guide portions may be connected to each other.

In the first and second embodiments, the induction section has an inclined surface that is inclined so as to approach the central axis 3a as it approaches the downstream side. However, the induction section is not limited to the above-mentioned shape. For example, the induction section may be configured to change the flow direction of the exhaust gas by a plane perpendicular to the central axis 3a.

In the first embodiment, at least a portion of the inclined surface 19a is disposed closer to the pipe 3 than the bent portion 15b, so that the fluid flowing downstream in the space 5 on the pipe 3 side than the bent portion 15b is directed toward the downstream surface of the valve body 21. However, the position where the inclined surface 19a is disposed is not limited to the above position, and the entire inclined surface 19a may be disposed closer to the rotating shaft 11 than the bent portion 15b.

(3b) The configuration of the valve body of the present disclosure is not particularly limited. For example, the valve body does not need to have a shape like the bent portion 15b shown in the first embodiment. Also, as in the valve device 501 shown in Figures 8A-8D, the end portion 513a of the wall surface 513 located on the upstream side of the valve body 511, which moves downstream when rotated in the opening direction, may be curved upstream in the closed position.

Further, in the above-described first and second embodiments, the valve body has the bent portion 15b, but the valve body does not have to have a bent portion.
In the first and second embodiments, the valve body is rotated between the closed position and the open position. That is, the closed position is a position where the angle between the valve body and the plane S (see FIG. 2A) perpendicular to the central axis 3a is relatively small, and the open position is a second position where the angle is relatively large. However, the first position and the second position are not limited to the angles exemplified in the above embodiments. For example, the first position may be a position inclined with respect to the plane S. Furthermore, in the second position, the angle between the valve body and the plane S may be an angle other than 90°.

(3c) In the first and second embodiments described above, a configuration in which a valve device is disposed in a cylindrical pipe 3 is exemplified. However, the specific shape of the pipe is not particularly limited. For example, as in the valve device 601 shown in Figures 9A-9D, the valve device 601 may be disposed in a pipe 603 having a substantially rectangular cross section. In this case, the upstream wall 613 may also be formed in a rectangular shape.

(3d) In the above first and second embodiments, a configuration has been exemplified in which the guide portion functions as a stopper that restricts the range of rotational displacement of the valve body. However, the stopper may be provided separately from the guide portion. In addition, the guide portion may be configured to suppress rotation of the valve body in either the closing direction or the opening direction.

(3e) In the above first and second embodiments, a configuration in which the rotating shaft is disposed at a position spaced from the central axis 3a of the exhaust flow passage is exemplified, but the rotating shaft may be disposed so as to intersect with the central axis 3a. In that case, it is advisable to adjust the shape of the valve body and the setting of the space 5 so that a torque in the opening direction is generated on the valve body in the closed position when exhaust gas flows.

(3f) Multiple functions possessed by one component in the above embodiments may be realized by multiple components, or one function possessed by one component may be realized by multiple components. Also, multiple functions possessed by multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Also, part of the configuration of the above embodiments may be omitted. Also, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

1,101,401,501,601...valve device, 3,603...piping, 3a...center axis, 5...space, 11,111...rotating axis, 11a,15e...imaginary plane, 13,613...upstream wall, 15...support, 15a...downstream surface, 15b...bent portion, 15c,15d...surface, 17...biasing portion, 19,119,201,203,301,303,411,413...guiding portion, 19a...inclined surface, 21,211,311,511...valve body, 21a...upstream end, 119a...main body, 119b...connecting portion, 513...wall surface, 513a...end, S...plane

Claims (5)

A valve device disposed in a pipe through which a fluid flows,
A rotation axis;
a valve element configured to be rotatably displaceable about the rotation axis between a first position where an angle between the valve element and a plane perpendicular to a central axis of the pipe is relatively small and a second position where the angle is relatively large;
a guide portion that guides a portion of the fluid flowing from upstream in a predetermined direction on the downstream side of the valve body that is located in a predetermined range between the first position and the second position;
Equipped with
a downstream surface that faces the downstream side when the valve body is located at the first position has a bent portion,
the bent portion is a portion that is bent such that, when the valve body is located in the predetermined range, an angle formed between a surface of the downstream surface downstream of the bent portion and the central axis is larger than an angle formed between a surface of the downstream surface upstream of the bent portion and the central axis,
The guide portion is configured to direct the fluid flowing downstream in a space on the pipe side relative to the bent portion toward the downstream surface when the valve body is in the predetermined range.
Valve gear. 2. The valve device according to claim 1,
The guide portion has an inclined surface that is inclined so as to approach the central axis as it goes downstream. The valve device according to claim 1 or 2 ,
The guide portion restricts a range of rotational displacement of the valve body. The valve device according to any one of claims 1 to 3 ,
The guide portion is a plate-shaped member extending in the longitudinal direction of the rotating shaft. The valve device according to any one of claims 1 to 4 ,
The valve assembly, wherein the rotating shaft is radially spaced from a central axis of the pipe.

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