silencer

Abstract

A muffler (1) mounted on a vehicle for allowing exhaust gas from an engine to flow downstream, comprising: a partition section (5) which is a plate-shaped section that separates an interior space (6) of the silencer (1) into an upstream space (6a) and a downstream space (6b) arranged in the flow direction, wherein the upstream space (6a) is a space on the side of an inlet (2a) of the exhaust gas in the silencer (1) and the downstream space (6b) is a space on the side of an outlet (3a) of the exhaust gas in the silencer (1), a tapered portion (10) which is a tubular portion projecting from the edge of an intermediate opening (12) provided at the partition portion (5) into the downstream space (6b), and is a tapered part which becomes smaller toward the downstream space (6b), a housing portion (20) which is a portion projecting from the partition portion (5) into the upstream space (6a), covering the intermediate opening (12), separating a space (6c) with the intermediate opening (12) and the upstream space (6a), and having an upstream opening (23) connecting the space (6c) and the upstream space (6a), a valve body (31) which is a portion disposed in the intermediate space (6c) and adjusts the degree of opening of the upstream opening (23) by rotating about a shaft (32) and moving between a closed position (31b) and an open position (31a), the degree of opening of the upstream opening (23) being reduced toward the closed position (31b), and an application section (33) which applies pressure to the valve body (31) in such a way that the valve body (31) moves into the closed position (31b), wherein the housing section (20) comprises: a side wall (21) which is a portion projecting from the partition portion (5) into the upstream space (6a), is arranged along the edge of the intermediate opening (12) and surrounds the intermediate opening (12), and a bottom portion (22) which is a wall-shaped portion provided with the upstream opening (23) and opposite the intermediate opening (12), wherein the housing section (20) has an edge portion (24) which is provided at the edge of the upstream opening (23) of the bottom portion (22) and projects from the edge of the upstream opening 23 into the space 6c, and a base portion (34) arranged on the edge portion (24) and intended to support the valve body (31).

Description

STATE OF THE ART

[0001] The present disclosure relates to a silencer.

[0002] The muffler of JP 2016-125473 A includes a partition plate that divides the interior of the muffler into upstream and downstream sides and includes a communication portion, and a valve device provided on the partition plate. The valve device includes a valve body that adjusts the amount of exhaust gas passing through the communication portion, and a housing that forms an accommodating space for accommodating the valve body. The housing covers the communication portion and is connected to a downstream pipe that guides the exhaust gas to an outlet. The valve body further adjusts the amount of exhaust gas passing through the communication portion by opening and closing a hole portion of the housing from the inside of the housing.

[0003] DE 11 2016 001 660 T5 discloses a similar silencer. OVERVIEW

[0004] Here, regarding the valve device of JP 2016-125473 A, an opening / closing mechanism such as a shaft and a spring is provided in the valve body. The opening / closing mechanism is located to the side of the front area of ​​the hole portion of the housing in the receiving space of the valve body. Furthermore, there is a possibility of turbulence or stagnation of the exhaust gas in the vicinity of the opening / closing mechanism in the receiving space, which can cause noise.

[0005] In one aspect of the present disclosure, it is desirable to suppress noise from the muffler. This problem is solved by the features of claim 1. The dependent claims specify expedient and advantageous further developments.

[0006] One aspect of the present disclosure is a muffler mounted on a vehicle for downwardly flowing exhaust gas from an engine, comprising a partition portion, a tapered portion, a housing portion, a valve body, and an impingement portion. The partition portion is a plate-shaped portion that partitions the interior of the muffler into upstream and downstream spaces arranged in the flow direction, the upstream space being a space on the inlet side of the exhaust gas in the muffler, and the downstream space being a space on the outlet side of the exhaust gas in the muffler. The tapered portion is a tubular portion that protrudes into the downstream space from the edge of an intermediate opening, which is an opening provided at the partition portion, and a tapered portion that becomes thinner toward the downstream space.The housing portion is a portion that protrudes from the partition portion into the upstream space, covers the intermediate opening, separates a space between the intermediate opening and the upstream space, and has an upstream opening connecting the intermediate space and the upstream space. The valve body is a portion disposed in the intermediate space and adjusts the opening degree of the upstream opening by rotating around a shaft and sliding between a closed position and an open position, decreasing the opening degree of the upstream opening toward the closed position. The urging portion urges the valve body to move the valve body toward the closed position.Then, when the upstream opening is projected onto the intermediate opening along the flow direction, the edge of the intermediate opening is positioned outside the edge of the upstream opening.

[0007] According to the above configuration, the upstream opening of the housing portion is positioned within the intermediate opening, and the tapered portion protrudes from the edge of the intermediate opening into the downstream space. Therefore, a larger space can be secured to the side of the front portion of the upstream opening in the intermediate space. Even if an opening / closing mechanism of the valve body, such as a shaft or an urging portion, is arranged to the side of the front portion of the upstream opening, a larger space can be secured near the opening / closing mechanism, and turbulence or stagnation of the exhaust gas near the opening / closing mechanism is suppressed.

[0008] Furthermore, the tapered section is inclined in such a way that it becomes thinner toward the downstream chamber. This allows the exhaust gas to flow freely in the intermediate space of the valve body, even when the upstream opening is opening.

[0009] Consequently, noise from the silencer can be suppressed. In one aspect of the present disclosure, the edge of the intermediate opening may be positioned outside the outer edge of the valve body when the valve body is projected toward the intermediate opening along the flow direction.

[0010] According to the above configuration, a larger space can be ensured at the side of the valve body in the intermediate space because the valve body is located within the intermediate opening. Even if the opening / closing mechanism of the valve body is provided at the edge portion of the valve body, a larger space can be ensured near the opening / closing mechanism, and turbulence or stagnation of the exhaust gas near the opening / closing mechanism is suppressed. Consequently, noise from the muffler can be suppressed.

[0011] According to the invention, the housing section has a side wall and a bottom section. The side wall is a section that protrudes from the partition section into the upstream space, is arranged along the edge of the intermediate opening, and surrounds the intermediate opening. The bottom section is a wall-shaped section provided with an upstream opening and located opposite the intermediate opening.

[0012] According to the above configuration, a larger space can be ensured near the edge of the intermediate port in the intermediate space, and as a result, a larger space is ensured to the side of the front portion of the upstream port and the valve body. Consequently, turbulence or stagnation of the exhaust gas near the opening / closing mechanism of the valve body can be suppressed, and as a result, muffler noise is suppressed.

[0013] In one aspect of the present disclosure, the length of the flow direction in the housing section may be greater than the length of the flow direction in the taper section. According to the above configuration, a larger space is ensured on the housing section side in the clearance. Therefore, a larger space can be ensured near the opening / closing mechanism of the valve body. Consequently, turbulence or stagnation of the exhaust gas near the opening / closing mechanism of the valve body can be suppressed, and as a result, muffler noise is suppressed.

[0014] In one aspect of the present disclosure, the opening on the downstream space side at the tapered portion may be considered a downstream opening. The shaft may be positioned laterally of the front portion of the upstream opening in the intermediate space and extend along the intermediate opening. A side opposite the upstream opening from the side on which the shaft is positioned may be considered a side opposite the shaft. The center portion of the downstream opening may be positioned on the side opposite the shaft compared to the center portion of the intermediate opening.

[0015] According to the above configuration, when the valve body moves from the closed position to the open position, the valve body is in a state where the portion on the shaft side is farthest from the upstream port. Therefore, more exhaust gases flow out from the portion on the shaft side into the upstream port. In contrast, in the above configuration, the inclination of the portion of the taper portion positioned on the shaft side is relatively large. Therefore, the exhaust gas flowing into the clearance from the portion on the shaft side in the upstream port can flow out freely into the downstream port. Consequently, turbulence or stagnation of the exhaust gas can be suppressed, and as a result, noise from the muffler is suppressed.

[0016] According to the invention, the housing section has a side wall and a bottom section. The side wall projects from the partition section into the upstream space. The bottom section is a wall-shaped section provided with an upstream opening and opposite the intermediate opening. The shaft can be positioned laterally of the front region of the upstream opening in the intermediate space and extend along the intermediate opening. A side that is opposite to the upstream opening from the side on which the shaft is positioned can be regarded as the side facing away from the shaft. On the side of the upstream opening on the bottom section facing away from the shaft, at least one sub-opening that is smaller than the upstream opening and connects the upstream space and the intermediate space can be provided.

[0017] According to the above configuration, at least one sub-port can be arranged at a position away from the opening / closing mechanism, such as the valve body shaft. Therefore, it is possible to suppress the exhaust gas from at least one sub-port from flowing into the vicinity of the opening / closing mechanism and causing turbulence or stagnation. This suppresses noise from the muffler.

[0018] In one aspect of the present disclosure, the at least one secondary opening may be opposite the inner wall of the tapered portion along the flow direction. According to the above configuration, the exhaust gas flowing into the intermediate space from the at least one secondary opening can be freely guided to the tapered portion. Consequently, turbulence or stagnation of the exhaust gas can be suppressed, and consequently, noise from the muffler is suppressed.

[0019] In one aspect of the present disclosure, the at least one secondary opening may be positioned above the lower end of the edge of the upstream opening. Since the sub-port is smaller than the upstream port, noise is likely to occur when water accumulated inside the muffler is sucked in by the sub-port, compared to a case where the water is sucked in by the upstream port. In contrast, according to the above configuration, the at least one sub-port is positioned above the lower end of the upstream port. Therefore, the water accumulated in the muffler is easily sucked in by the upstream port, and the suction of water from the at least one sub-port can be suppressed. Consequently, noise from the muffler can be suppressed.

[0020] In one aspect of the present disclosure, the upstream opening may be positioned below the inlet to the interior space. According to the above configuration, the water can enter the upstream opening and be guided to the downstream space before the water accumulated in the muffler enters the inlet into the interior of the muffler. This allows the water accumulated inside the muffler to be guided downstream of an exhaust duct of the vehicle, and as a result, the water can be properly discharged to the outside.

[0021] In one aspect of the present disclosure, the housing portion may include a bottom portion, a side wall, and at least one attachment portion. The bottom portion is a wall-shaped portion provided with an upstream opening and facing the intermediate opening. The side wall is arranged to surround the intermediate space and form an opening facing the bottom portion. The attachment portion protrudes outward from a portion forming the edge of the opening on the side wall. At least one attachment portion may be connected to the partition portion.

[0022] According to the above configuration, the housing portion can be appropriately connected to the partition portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] An embodiment of the present disclosure will be described below with reference to the drawings. Fig. 1 is a plan view transparently showing the internal structure of a muffler. Fig. 2 is a II-II sectional view in Fig. 1. Fig. 3 is a III-III sectional view in Fig. 1. Fig. 4 is a sectional view transparently showing the internal structure of a taper portion and a housing portion. Fig. 5 is a front view of a housing section. Fig. 6 is a front view of a taper section. EMBODIMENT OF THE INVENTION

[0024] The embodiment of the present disclosure is not limited to the following embodiment and may take various forms as long as it belongs to the technical scope of the present disclosure. [Regarding the overall design]

[0025] A silencer 1 according to the present embodiment shown in Fig. 1 is provided in an exhaust duct that allows the exhaust gas of a vehicle engine to flow downward. The outer shape of the muffler 1 is, for example, a columnar shape with a substantially rectangular cross-section, and the muffler 1 is provided with an upstream end plate 2, a downstream end plate 3, and a shell 4.

[0026] The shell 4 is a tubular portion extending in the front-rear direction and having a substantially rectangular cross-section, and forms the outer peripheral surface of the muffler 1. The upstream end plate 2 and the downstream end plate 3 are plate-like portions that form the bottom surface of the muffler 1 and close the openings formed at both ends of the shell 4. The upstream end plate 2 and the downstream end plate 3 are opposed in the front-rear direction, with the upstream end plate 2 positioned at the front and the downstream end plate 3 positioned at the rear. Hereinafter, a space surrounded by the shell 4, the upstream end plate 2, and the downstream end plate 3 is referred to as the interior space 6.

[0027] Here, the longitudinal direction of the cross section of the muffler 1 is referred to as the left-right direction. Furthermore, the muffler 1 is mounted on the vehicle in a state where one short side of the cross section is positioned at the top and the other side is positioned at the bottom. However, the direction in which the upstream end plate 2 and the downstream end plate 3 of the muffler 1 oppose each other when mounted on the vehicle can be determined according to the circumstances. That is, the front-rear and left-right directions of the muffler 1 mounted on the vehicle do not necessarily coincide with the front-rear and left-right directions of the vehicle.

[0028] The upstream end plate 2 has an inlet 2a into which an upstream pipe 2b (described later) is inserted. The inlet 2a is positioned on the left side of the center of the upstream end plate 2 in the left-right direction. The downstream end plate 3 further has an outlet 3a into which a downstream pipe 3b (described later) is inserted. The outlet 3a is positioned on the right side of the center of the downstream end plate 3 in the left-right direction.

[0029] The muffler 1 is further provided with a separating section 5, an upstream pipe 2b, a downstream pipe 3b, a tapered section 10, a housing section 20, and a valve device 30. These configurations are explained below. [Regarding the dividing section]

[0030] The separating section 5 is a plate-like section that separates the interior space 6, as shown in the Fig. 1 to 3. The partition section 5 is arranged parallel or substantially parallel to the upstream end plate 2 and the downstream end plate 3. Therefore, the internal space 6 is divided by the partition section 5 into an upstream space 6a and a downstream space 6b arranged in the front-rear direction. The upstream space 6a is positioned on the upstream end plate 2 side (in other words, on the inlet 2a side), and the downstream space 6b is positioned on the downstream end plate 3 side (in other words, on the outlet 3a side).

[0031] The edge of the separating section 5 is bent forward in an L-shape. The separating section 5 is connected to the inside of the shell 4 via the bent section.

[0032] The partition wall 5 further includes an intermediate opening 12 described later, an upstream pipe opening 5a, and at least one hole 5b that allows the upstream space 6a and the downstream space 6b to communicate. The upstream pipe opening 5a is positioned on the left side of the center of the partition section 5 in the left-right direction. The tapered section 10 and the housing section 20 are further provided on the partition section 5. The tapered section 10 and the housing section 20 are positioned on the right side of the upstream pipe opening 5a.

[0033] The upstream pipe 2b is further arranged in a state where its front end is connected to the inlet 2a and penetrates the partition portion 5 through the upstream pipe opening 5a. The upstream pipe 2b extends in the front-rear direction and crosses the upstream space 6a, with the rear end of the upstream pipe 2b reaching the downstream space 6b. That is, the outer peripheral surface of the upstream pipe 2b is supported by the rim portion surrounding the upstream pipe opening 5a. At least one hole 2c is further provided at a portion of the upstream pipe 2b located in the upstream space 6a. [Regarding the tapering section]

[0034] As in the Fig. 1 and Fig. As shown in Figure 4, the tapered portion 10 is a tubular portion that protrudes from the edge of the intermediate opening 12, which is an opening provided in the partition portion 5, into the downstream space 6b (in other words, toward the rear). The tapered portion 10 has a tapered shape and becomes thinner toward the rear. That is, the tapered portion 10 has a cross-sectional area that decreases toward the rear.

[0035] Here, in the tapered portion 10, an opening on the downstream space 6b side is considered the downstream opening 11. Furthermore, the intermediate opening 12 corresponds to an opening of the tapered portion 10 on the upstream space 6a side. The intermediate opening 12 is substantially elliptical, for example. Further, the downstream opening 11 is circular or substantially circular, for example. The tapered portion 10 can also be formed by machining a partial shape of the partition portion 5.

[0036] The downstream opening 11 of the tapered portion 10 is further connected to the front end of the downstream pipe 3b. Specifically, a rearwardly extending edge portion 13 is provided at the edge of the downstream opening 11, and the edge portion 13 is connected to the downstream pipe 3b. The rear end of the downstream pipe 3b is connected to the outlet 3a, and the exhaust gas flowing out of the downstream opening 11 is guided to the outlet 3a through the downstream pipe 3b. It is also possible for the rear end of the downstream pipe 3b not to reach the outlet 3a and to be disposed in the downstream space 6b. Furthermore, the downstream pipe 3b need not be provided. [Regarding the housing section]

[0037] As in Fig. 1 and Fig. 4, the housing portion 20 is provided on the partition portion 5 so as to protrude into the upstream space 6a and covers the intermediate opening 12 of the partition portion 5. The housing portion 20 partitions the intermediate space 6c and the upstream space 6a. The intermediate space 6c is a space having the intermediate opening 12 and is formed between the housing portion 20 and the tapered portion 10. The housing portion 20 has an upstream opening 23 connecting the intermediate space 6c and the upstream space 6a. The upstream opening 23 is, for example, circular or substantially circular, and the upstream opening 23, the intermediate opening 12, and the downstream opening 11 are arranged in parallel or substantially parallel.

[0038] As in Fig. 4 and Fig. As shown in Figure 5, the housing section 20 has a side wall 21, a bottom section 22, and at least one fastening section 26. In the present embodiment, three fastening sections 26 are provided as an example.

[0039] The bottom section 22 is a wall-shaped section opposite the intermediate opening 12. The side wall 21 protrudes from the partition section 5 into the upstream space 6a (in other words, forward). The side wall 21 is arranged along the edge of the intermediate opening 12 and is arranged to surround the intermediate opening 12 (in other words, the intermediate space 6c). In detail, all portions of the side wall 21 are arranged at the edge or near the intermediate opening 12. The present invention is not limited thereto, and the side wall 21 may also be arranged entirely or partially inside or outside the edge of the intermediate opening 12. In other words, the side wall 21 protrudes from the edge of the bottom portion 22 and forms an opening opposite the bottom portion 22.

[0040] The fastening portion 26 is a flange-like portion that protrudes from the edge of the opening formed by the side wall 21 outside the opening. For example, the housing portion 20 is fastened to the partition portion 5 by welding the fastening portion 26 to the partition portion 5.

[0041] The bottom portion 22 further includes the above-described upstream opening 23 and at least one secondary opening 25. In the present embodiment, two secondary openings 25 are provided as an example. The upstream opening 23 is opposite the intermediate opening 12. A peripheral portion 24 is provided at the edge of the upstream opening 23. The peripheral portion 24 is a portion formed by bending a portion around the upstream opening 23 into the gap 6c in an L-shape, and protrudes from the edge of the upstream opening 23 into the gap 6c.

[0042] The sub-port 25 is an opening connecting the intermediate space 6c and the upstream space 6a, and is smaller than the upstream port 23. Each sub-port 25 is further positioned on a side 32a facing away from the shaft (in other words, the lower left side) of the upstream port 23. The side 32a facing away from the shaft will be described later.

[0043] The sub-opening 25 is also located opposite the inner wall of the tapered portion 10 along the front-rear direction. Specifically, the sub-opening 25 is located opposite a portion where the inclination of the tapered portion 10 relative to the partition portion 5 is relatively high.

[0044] As in Fig. 5, one of the two sub-portions 25 in the present embodiment is positioned above the lowermost portion (hereinafter referred to as the lower end portion) of the upstream port 23. It is also possible that all of the sub-portions 25 are positioned above the lower end portion.

[0045] As in the Fig. 2 and Fig. 3, the upstream opening 23 is positioned below the upstream pipe opening 5a of the partition section 5. Furthermore, the inlet 2a of the upstream end plate 2 faces the upstream pipe opening 5a in the front-rear direction. Therefore, the upstream opening 23 is positioned below the inlet 2a. In detail, the center portion of the upstream opening 23 is positioned below the center portion of the inlet 2a. The center portion of the upstream opening 23 and the inlet 2a may also be, for example, the center or center of gravity of them. [valve device]

[0046] The valve device 30 is arranged in the housing section 20 (in other words in the space 6c), as shown in the Fig. 1, Fig. 4 and Fig. 5. The valve device 30 is provided with a valve body 31, a shaft 32, an urging portion 33, a base portion 34, and a support portion 35.

[0047] The base portion 34 is a tubular portion provided at the edge portion 24 of the upstream opening 23. The base portion 34 is a tapered portion that projects from the edge portion 24 into the gap 6c (in other words, toward the rear) and becomes thinner toward the front.

[0048] The support portion 35 is a portion provided at the top right of the base portion 34. The valve body 31 is supported by the base portion 34 and the support portion 35. The shaft 32 for rotating the valve body 31 is also provided on the support portion 35.

[0049] The shaft 32 is positioned to the side of the front portion of the upstream opening 23 in the intermediate space 6c (for example, the upper right of the front portion) and extends along the intermediate opening 12. In detail, the shaft 32 does not cross the front portion of the upstream opening 23 and extends parallel or substantially parallel to the intermediate opening 12 and the upstream opening 23. Hereinafter, with respect to the upstream opening 23, the side on which the shaft 32 is positioned is referred to as the shaft side, and the side facing away from the shaft is referred to as the shaft-facing side 32a. In detail, the shaft-facing side 32a may also be in a direction that is orthogonal or substantially orthogonal to the shaft 32 and that extends from the shaft 32 into the upstream opening 23 parallel or substantially parallel to the upstream opening 23.

[0050] The valve body 31 is rotatably supported by the shaft 32 provided at the peripheral portion of the valve body 31. The valve body 31 approaches or moves away from the base portion 34 due to this shaft rotation. As a result, the valve body 31 is displaced between an open position 31a and a closed position 31b, and the opening degree of the upstream opening 23 is adjusted by this displacement. Further, when the valve body 31 is in the open position 31a, the opening degree of the upstream opening 23 is maximum. The opening degree of the upstream opening 23 decreases as the valve body 31 moves toward the closed position 31b. The opening degree of the upstream opening 23 when the valve body 31 is in the open position 31a and the closed position 31b can be determined according to the circumstances.In the present embodiment, the upstream opening 23 is completely closed when the valve body 31 is in the closed position 31b. However, when the valve body 31 is in the closed position 31b, the upstream opening 23 may also be partially open.

[0051] The biasing portion 33 biases the valve body 31 to displace the valve body 31 toward the closed position 31b. In the present embodiment, the biasing portion 33 is formed, for example, as a torsion coil spring arranged around the shaft 32. However, the biasing portion 33 may also be formed, for example, as a compression coil spring, a tension coil spring, or a leaf spring.

[0052] Due to the urging of the urging portion 33, the valve body 31 is normally held in the closed position 31b. However, the valve body 31 is pressed by exhaust gas flowing into the muffler 1 from the upstream space 6a side. When the amount of exhaust gas flowing into the muffler 1 increases and the force with which the exhaust gas presses the valve body 31 exceeds the force exerted on the valve body 31 by the urging portion 33, the valve body 31 shifts toward the open position 31a, and the upstream opening 23 is opened. As a result, the exhaust gas flows from the upstream space 6a into the space 6c through the upstream opening 23. [Regarding the position of each component]

[0053] As in Fig. 5 and Fig. 6, the edge of the intermediate opening 12 is positioned outside the edge of the upstream opening 23 of the housing portion 20, which is projected onto the intermediate opening 12 (in other words, the tapered portion 10) along the front-rear direction, and outside the outer edge of the valve body 31. That is, the entire valve body 31 is positioned in the front region of the intermediate opening 12. In Fig. 6, the valve device 30 is shown by an imaginary line.

[0054] As in the Fig. 4 and Fig. 6, the center portion 11a of the downstream opening 11, which is projected onto the intermediate opening 12 along the front-rear direction, is positioned on the shaft-reverse side 32a compared to the center portion 12a of the intermediate opening 12. The center portion of the downstream opening 11 and the intermediate opening 12 can be determined in the same manner as the center portion of the above-described upstream opening 23 and the inlet 2a (in Fig. 4 (for simplicity, the central axis of the downstream opening 11 is designated 11b and the central axis of the intermediate opening 12 is designated 12b). Therefore, the degree of inclination with respect to the separating section 5 in the section positioned in the front region of the shaft 32 and the loading section 33, etc., of the valve device 30 in the tapered section 10 is relatively low. Furthermore, it is also possible for the degree of inclination of this section to be equal to or substantially equal to the degree of inclination of the valve body 31 located in the open position 31a. In contrast, the degree of inclination of the section of the tapered section 10 positioned in the front region of the at least one secondary opening 25 of the housing section 20 is relatively high.

[0055] The length of the housing section 20 in the front-to-back direction is further referred to as the housing thickness 27, and the length of the tapered part in the tapered section 10 in the front-to-back direction is referred to as the tapered section thickness 14. As shown in Fig. 4, the housing thickness 27 is, as an example, greater than the thickness 14 of the tapered section. [Effects]

[0056] Regarding the muffler 1 according to the above embodiment, when low-pressure exhaust gas flows in from the upstream pipe 2b, a portion of the exhaust gas flows into the downstream space 6b from the rear end of the upstream pipe 2b. Thereafter, the exhaust gas flows into the upstream space 6a from the at least one hole 5b of the partition portion 5, and further flows into the downstream pipe 3b from the sub-portion 25. A portion of the exhaust gas further flows into the upstream space 6a from the at least one hole 2c of the upstream pipe 2b, and then flows into the downstream pipe 3b from the sub-portion 25.

[0057] In contrast, when high-pressure exhaust gas flows in from the upstream pipe 2b, a portion of the exhaust gas flows downward through the same path as the low-pressure exhaust gas flowing in. In addition, a portion of the high-pressure exhaust gas flows from the rear end of the upstream pipe 2b into the downstream space 6b and then from at least one hole 5b of the partition portion 5 into the upstream space 6a. Then, the exhaust gas pushes the valve body 31 downstream, flows from the upstream opening 23 into the space 6c, and further flows downward along the tapered portion 10 into the downstream pipe 3b. [Effects] (1) According to the above-described embodiment, a larger space can be secured to the side of the front portion of the upstream opening 23 in the intermediate space 6c depending on the positions of the intermediate opening 12 and the upstream opening 23. Therefore, even if the opening / closing mechanism of the valve body 31, such as the shaft 32 or the urging portion 33, is disposed to the side of the front portion of the upstream opening 23, a larger space can be secured near the opening / closing mechanism, and turbulence or stagnation of the exhaust gas near the opening / closing mechanism is suppressed.

[0058] In addition, the tapered section 10 slopes in such a way that it becomes thinner toward the downstream space 6b. Therefore, even during the opening of the intermediate opening 12, the exhaust gas can flow freely in the area on the side of the intermediate opening 12 of the valve body 31 in the intermediate space 6c.

[0059] Consequently, noise from the silencer 1 can be suppressed. (2) Furthermore, a larger space can be ensured at the side of the valve body 31 in the intermediate space 6c depending on the positions of the valve body 31 and the intermediate orifice 12. Therefore, even if the opening / closing mechanism of the valve body 31 is provided at the edge portion of the valve body 31, a larger space can be ensured near the opening / closing mechanism, and turbulence or stagnation of the exhaust gas near the opening / closing mechanism is suppressed. (3) Furthermore, the side wall 21 of the housing portion 20 is arranged along the edge of the intermediate opening 12. Therefore, a larger space can be secured near the edge of the intermediate opening 12 in the clearance 6c, and as a result, a larger space is secured to the side of the front portion of the upstream opening 23 and to the side of the valve body 31. Consequently, turbulence or stagnation of the exhaust gas near the opening / closing mechanism of the valve body 31 can be suppressed. (4) Furthermore, the casing thickness 27 is greater than the thickness 14 of the tapered portion. Therefore, a larger space is secured on the casing portion 20 side in the clearance 6c. Therefore, a larger space can be secured near the opening / closing mechanism of the valve body 31. Consequently, in the configuration in which the valve device 30 is housed in the casing portion 20, it is possible to reduce the exhaust flow disturbed by the valve device 30 and suppress turbulence or stagnation of the exhaust gas near the opening / closing mechanism of the valve body 31. (5) Furthermore, the tapered portion 10 has a relatively large inclination of the portion positioned on the shaft-side 32a. Therefore, in the tapered portion 10, the front-to-rear position of the rear end portion in the inclined portion on the shaft-side 32a and the front-to-rear position of the rear end portion in the inclined portion on the shaft side can coincide with each other. Furthermore, in the inclined portion on the shaft-side 32a, the exhaust gas flowing into the clearance 6c from the upstream opening 23 can freely flow out into the downstream opening 11. Consequently, turbulence or stagnation of the exhaust gas can be suppressed. (6) Furthermore, the at least one sub-port 25 is provided on the shaft-remote side 32a of the upstream port 23. Therefore, the at least one sub-port 25 can be arranged at a position remote from the opening / closing mechanism of the valve body 31. Consequently, it is possible to suppress the exhaust gas from the at least one sub-port 25 from flowing into the vicinity of the opening / closing mechanism and the occurrence of turbulence or stagnation. (7) Furthermore, the at least one sub-portion 25 faces the inner wall of the tapered portion 10 along the front-rear direction. Therefore, the exhaust gas flowing from the at least one sub-portion 25 into the gap 6c can be freely guided into the tapered portion 10. Consequently, turbulence or stagnation of the exhaust gas can be suppressed. (8) Furthermore, the at least one sub-port 25 is positioned above the lower end of the edge of the upstream port 23. Therefore, the water accumulated inside the muffler 1 is easily sucked into the upstream port 23, and the water can be suppressed from being sucked into the at least one sub-port 25. Consequently, noise from the muffler 1 can be suppressed. (9) Furthermore, the upstream opening 23 is positioned below the inlet 2a. Therefore, the water can enter the upstream opening 23 and be guided into the downstream space 6b before the water accumulated in the muffler 1 enters the inlet 2a. This allows the water accumulated in the muffler 1 to be guided downstream of the exhaust passage of the vehicle, and as a result, the water can be properly discharged to the outside. (10) Furthermore, the housing portion 20 is connected to the partition portion 5 by the three fixing portions 26. Therefore, the housing portion 20 can be properly connected to the partition portion 5. [Other embodiments]

[0060] In the above embodiment, a plurality of functions of a component may be realized by a plurality of components, or a function of a component may be realized by a plurality of components. Furthermore, a plurality of functions shared by a plurality of components may be realized by a single component, or a function realized by a plurality of components may also be realized by a single component. Furthermore, some of the configurations of the above embodiment may be omitted. Furthermore, at least some of the configurations of the above embodiment may be added to or replaced by the other configurations of the embodiment. [Correspondence to the patent claims]

[0061] The front-to-rear direction in the above embodiment corresponds to an example of the flow direction. Furthermore, the tapered part of the tapered portion 10 corresponds to an example of the tapered portion.

Claims

[1] Silencer (1) mounted on a vehicle and allowing exhaust gas from an engine to flow downstream, provided with: a partition section (5) which is a plate-shaped section that separates an interior space (6) of the silencer (1) into an upstream space (6a) and a downstream space (6b) arranged in the flow direction, wherein the upstream space (6a) is a space on the side of an inlet (2a) of the exhaust gas in the silencer (1) and the downstream space (6b) is a space on the side of an outlet (3a) of the exhaust gas in the silencer (1), a tapered portion (10) which is a tubular portion projecting from the edge of an intermediate opening (12) provided at the partition portion (5) into the downstream space (6b), and is a tapered part which becomes smaller toward the downstream space (6b), a housing portion (20) which is a portion projecting from the partition portion (5) into the upstream space (6a), covering the intermediate opening (12), separating a space (6c) with the intermediate opening (12) and the upstream space (6a), and having an upstream opening (23) connecting the space (6c) and the upstream space (6a), a valve body (31) which is a portion disposed in the intermediate space (6c) and adjusts the degree of opening of the upstream opening (23) by rotating about a shaft (32) and moving between a closed position (31b) and an open position (31a), the degree of opening of the upstream opening (23) being reduced toward the closed position (31b), and an application section (33) which applies pressure to the valve body (31) in such a way that the valve body (31) moves into the closed position (31b), wherein the housing section (20) comprises: a side wall (21) which is a portion projecting from the partition portion (5) into the upstream space (6a), is arranged along the edge of the intermediate opening (12) and surrounds the intermediate opening (12), and a bottom portion (22) which is a wall-shaped portion provided with the upstream opening (23) and opposite the intermediate opening (12), wherein the housing section (20) has an edge portion (24) which is provided at the edge of the upstream opening (23) of the bottom portion (22) and projects from the edge of the upstream opening 23 into the space 6c, and a base portion (34) arranged on the edge portion (24) and intended to support the valve body (31). [2] Silencer (1) according to claim 1, wherein, when the valve body (31) is projected along the flow direction onto the intermediate opening (12), the edge of the intermediate opening (12) is positioned outside the outer edge of the valve body (31). [3] Silencer (1) according to one of claims 1 or 2, wherein the length (27) of the flow direction in the housing section (20) is greater than the length of the flow direction in the tapered section (10). [4] Silencer (1) according to one of claims 1 to 3, wherein the opening on the side of the downstream space (6b) at the tapered portion (10) is regarded as the downstream opening (11), the shaft (32) is positioned laterally of the front region of the upstream opening (23) in the intermediate space (6c) and extends along the intermediate opening (12), a side which, with respect to the upstream opening (23), is opposite the side on which the shaft (32) is positioned is considered to be the side (32a) opposite the shaft, and a central portion (11a) of the downstream opening (11) is positioned on the side (32a) facing away from the shaft compared to a central portion (12a) of the intermediate opening (12). [5] Silencer (1) according to one of claims 1 to 4, where in the housing section (20) the shaft (32) is positioned laterally of the front region of the upstream opening (23) in the intermediate space (6c) and extends along the intermediate opening (12), a side which, with respect to the upstream opening (23), is opposite the side on which the shaft (32) is positioned is considered to be the side (32a) opposite the shaft, and on the side (32a) of the upstream opening (23) facing away from the shaft, at least one secondary opening (25) is provided on the bottom section (22), which is smaller than the upstream opening (23) and connects the upstream space (6a) and the intermediate space (6c). [6] Silencer (1) according to claim 5, wherein the at least one secondary opening (25) is opposite the inner wall of the tapered section (10) along the flow direction. [7] Silencer (1) according to claim 5 or 6, wherein the at least one secondary opening (25) is positioned above the lower end of the edge of the upstream opening (23). [8] Silencer (1) according to one of claims 1 to 7, wherein the upstream opening (23) is positioned below the inlet into the interior space (6). [9] Silencer (1) according to one of claims 1 to 8, wherein the side wall (21) is arranged such that it surrounds the intermediate space (6c) and forms an opening opposite the bottom portion (22), and has at least one fastening portion (26) which projects outwards from a portion which forms the edge of the opening on the side wall (21), wherein the at least one fastening portion (26) is connected to the separating portion (5).

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