JPWO2016084616A1 - Exhaust system - Google Patents

Abstract

The exhaust device includes an exhaust pipe and an inner surface protrusion. The exhaust pipe has an exhaust passage, and a position along the vertical direction in the exhaust passage rises toward the downstream side of the exhaust passage. At least one inner surface protrusion is provided on the inner surface of the exhaust pipe, and protrudes inside the exhaust pipe from the inner surface of the exhaust pipe.

Description

Cross-reference of related applications

  This international application claims priority based on Japanese Patent Application No. 2014-239017 filed with the Japan Patent Office on November 26, 2014, and Japanese Patent Application No. 2014-239017 The entire contents are incorporated by reference into this international application.

  The present disclosure relates to an exhaust device that forms an exhaust passage through which exhaust gas flows.

In this type of exhaust device, it is known that when exhaust gas is cooled in the exhaust passage, moisture contained in the exhaust gas is condensed to generate condensed water (see Patent Document 1).
For example, an exhaust device provided in an automobile includes an exhaust pipe for guiding exhaust gas discharged from an internal combustion engine to the outside of the automobile, and condensed water is generated when the exhaust gas is cooled in an exhaust passage formed by the exhaust pipe. . The generated condensed water is usually discharged to the outside of the automobile together with the exhaust gas.

Japanese Patent No. 4983052

  By the way, this kind of exhaust pipe may include a bent portion that is bent upward for convenience of being arranged so as not to interfere with other components. On the downstream side of such a bent portion, an exhaust passage is formed in which the position along the vertical direction rises toward the downstream side of the bent portion. In this case, in a state where the flow rate of the exhaust gas discharged from the internal combustion engine is low, the condensed water does not easily rise from the upstream side to the downstream side of the bent portion, and is not discharged to the outside of the exhaust passage, but is collected in the bent portion. It becomes easy. When the condensed water accumulated in the exhaust passage is frozen in this way, the flow of exhaust gas in the exhaust passage is hindered.

  In one aspect of the present disclosure, in an exhaust apparatus provided with an exhaust passage in which a position along the vertical direction rises toward the downstream side, it is desirable that condensed water be easily discharged to the outside of the exhaust passage.

  One aspect of the present disclosure is an exhaust device that includes an exhaust pipe and an inner surface protrusion. The exhaust pipe has an exhaust passage, and a position along the vertical direction in the exhaust passage rises toward the downstream side of the exhaust passage. At least one inner surface protrusion is provided on the inner surface of the exhaust pipe, and protrudes inside the exhaust pipe from the inner surface of the exhaust pipe.

  According to such a configuration, since the inner surface protrusion is provided in the exhaust flow path whose position along the vertical direction rises toward the downstream side of the exhaust flow path, compared with a configuration in which the inner surface protrusion is not provided. Thus, the condensed water can be easily discharged to the outside of the exhaust passage.

  In the above configuration, the plurality of inner surface protrusions may be arranged in pairs with an inner surface line being a line along the axis of the exhaust pipe on the inner surface of the exhaust pipe. According to such a configuration, the condensed water is easily accelerated between the plurality of inner surface protrusions arranged in pairs with the inner surface line interposed therebetween. For this reason, the condensed water can be easily raised from the upstream side to the downstream side of the exhaust passage, and can be easily discharged to the outside of the exhaust passage.

  In the above configuration, the pair of inner surface protrusions sandwiching the inner surface line may be formed such that a gap sandwiching the inner surface line widens toward the downstream side of the exhaust passage. According to such a configuration, the effect of making it difficult for the condensed water to flow backward from the downstream side to the upstream side of the exhaust passage can be obtained.

  The said structure WHEREIN: The height on the basis of the inner surface of an inner surface protrusion part may become low toward the downstream of an exhaust flow path. According to such a configuration, it is possible to make it difficult for the flow of condensed water from the upstream side to the downstream side of the exhaust flow path to decline.

  In the above configuration, the inner protrusion may be provided at least on the lower side in the vertical direction on the inner surface of the exhaust pipe. According to such a configuration, the condensed water collected on the lower side in the vertical direction on the inner surface of the exhaust pipe due to gravity is more upstream than the configuration in which the inner surface protrusion is not provided on the lower side in the vertical direction. As a result, it can be easily lifted from the side to the downstream side, and can be easily discharged to the outside of the exhaust passage.

  In the above configuration, the inner surface line may be a line connecting the lowest vertical points on the inner surface. According to such a configuration, the inner surface line is present at the position where the condensed water is collected most by gravity, and the inner surface protrusions are arranged in pairs with the inner surface line interposed therebetween. It becomes easy to gather between the arranged internal projections. For this reason, compared with the configuration in which the innermost line does not exist at the lowest point in the vertical direction, the condensed water can be easily raised from the upstream side to the downstream side of the exhaust passage, and is easily discharged to the outside of the exhaust passage. can do.

  In the above configuration, the inner surface protrusion may be provided on the upper side in the vertical direction on the inner surface of the exhaust pipe. According to such a configuration, the exhaust gas flowing through the exhaust passage is accelerated by the inner surface protrusion provided on the upper surface of the exhaust pipe in the vertical direction and guided downward in the vertical direction. The flow velocity is also accelerated. For this reason, the condensed water can be easily raised from the upstream side to the downstream side of the exhaust passage, and can be easily discharged to the outside of the exhaust passage.

It is an external view of the exhaust system of an embodiment. 2A is a sectional view taken along line IIA-IIA in FIG. 1, FIG. 2B is a sectional view taken along line IIB-IIB in FIG. 2A, and FIG. 2C is a sectional view taken along line IIC-IIC in FIG. 3A is a partially enlarged view of FIG. 2B, and FIG. 3B is a cross-sectional view taken along the line IIIB-IIIB of FIG. 3A. FIG. 4A is a diagram showing a simulation result when exhaust gas flows from the upstream side to the downstream side of the exhaust flow channel in the exhaust flow channel of this embodiment, and FIG. 4B is the downstream of the exhaust flow channel in the exhaust flow channel of this embodiment. It is a figure which shows the simulation result in case exhaust gas flows into the upstream from the side. 5A is a diagram corresponding to the IIIB-IIIB cross-sectional view of FIG. 2B in the first comparative example, and FIG. 5B is a case where exhaust gas flows from the upstream side to the downstream side of the exhaust channel in the exhaust channel of the first comparative example. FIG. 5C is a diagram showing a simulation result when exhaust gas flows from the downstream side to the upstream side of the exhaust passage in the exhaust passage of the first comparative example. 6A is a diagram corresponding to the IIIB-IIIB cross-sectional view of FIG. 2B in the second comparative example, and FIG. 6B is a case where exhaust gas flows from the upstream side to the downstream side of the exhaust channel in the exhaust channel of the second comparative example. FIG. 6C is a diagram showing a simulation result when exhaust gas flows from the downstream side to the upstream side of the exhaust passage in the exhaust passage of the second comparative example.

  DESCRIPTION OF SYMBOLS 1 ... Upstream exhaust pipe, 2 ... Muffler, 3, 5, 6 ... Downstream exhaust pipe, 4 ... Suspension member 10, 20, 30 ... Lower surface bead, 11 ... Upper surface bead, 100 ... Exhaust system, C ... Bottom line .

Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings.
[1. Constitution]
An exhaust system 100 shown in FIG. 1 is a device that discharges exhaust gas discharged from an internal combustion engine of an automobile to the outside of an exhaust passage described later. The exhaust system 100 includes an upstream exhaust pipe 1, a muffler 2, and a downstream exhaust pipe 3.

The upstream exhaust pipe 1 is disposed on the downstream side of the internal combustion engine, and forms an exhaust flow path that guides exhaust gas discharged from the internal combustion engine to the muffler 2.
The muffler 2 reduces exhaust noise emitted from the internal combustion engine. The muffler 2 is connected to the downstream end of the upstream exhaust pipe 1.

  The downstream exhaust pipe 3 forms an exhaust passage, and the exhaust passage guides the exhaust gas flowing out from the muffler 2 to the outside of the exhaust passage. The upstream end of the downstream exhaust pipe 3 is connected to the muffler 2, and the downstream exhaust pipe 3 is a component of the automobile in the middle from the upstream end to the downstream end of the downstream exhaust pipe 3. It is bent so as not to interfere with the suspension member 4. Specifically, the downstream exhaust pipe 3 has an exhaust passage bent so that the position along the vertical direction rises toward the downstream side of the exhaust passage so as to pass through the upper part of the suspension member 4. Is formed.

As shown in FIGS. 2A to 2C, a lower surface bead 10 and an upper surface bead 11 are formed on the inner surface of the downstream side exhaust pipe 3.
As shown in FIG. 2A, the lower surface bead 10 is provided on the lower side in the vertical direction (the lower side in FIG. 2A) on the inner surface of the downstream exhaust pipe 3 and protrudes inward from the inner surface of the downstream exhaust pipe 3. Yes. As shown in FIG. 2B, the lower surface bead 10 has a vertical lowest point on the inner surface of the downstream exhaust pipe 3 (specifically, the downstream exhaust pipe 3 has a cross section parallel to the vertical direction of the downstream exhaust pipe 3). They are arranged so as to be paired (symmetric in this example) across the lowest line C, which is a line connecting the lowest points of the inner surface. A plurality (six sets in this embodiment) of the lower surface beads 10 paired in this way are arranged along the axial direction of the downstream side exhaust pipe 3 at a constant interval. Further, the pair of lower surface beads 10 arranged with the lowest line C interposed therebetween are arranged so that a gap formed between them spreads in a so-called taper shape toward the downstream side of the exhaust passage. Further, as shown in FIG. 3B (cross-sectional view of the lower surface bead 10 shown in FIG. 3A), the lower surface bead 10 has a height with respect to the inner surface of the downstream side exhaust pipe 3 from the upstream side to the downstream side of the exhaust passage. It is formed so as to become lower. In the present embodiment, as the lower surface bead 10, a so-called water droplet-shaped protrusion including a circular arc in part is formed, but the shape of the lower surface bead 10 is not particularly limited.

  As shown in FIG. 2C, the upper surface bead 11 is provided on the upper surface in the vertical direction (upper side in FIG. 2C) on the inner surface of the downstream exhaust pipe 3, and protrudes inward from the inner surface of the downstream exhaust pipe 3. Specifically, one upper surface bead 11 is disposed between the protrusion vertices of each lower surface bead 10 along the axial direction of the downstream side exhaust pipe 3. That is, the upper surface beads 11 are alternately arranged with the lower surface beads 10 along the axial direction of the downstream side exhaust pipe 3 at the same fixed intervals as the lower surface beads 10 (in this embodiment, between the projection vertices of each lower surface bead 10. (Equally spaced so as to be located at the midpoint). The upper surface bead 11 has a function of accelerating the exhaust gas flowing through the exhaust passage and guiding it downward in the vertical direction. The shape of the upper surface bead 11 is not particularly limited.

  As shown in FIGS. 2C and 3B, the “bead” of the lower surface bead 10 and the upper surface bead 11 means a protrusion formed by being recessed from the outer surface of the downstream side exhaust pipe 3 toward the inner surface.

  Next, simulation results will be described. FIG. 5A is a cross-sectional view of the lower surface bead 20 formed in the downstream side exhaust pipe 5 of the first comparative example, and the height of the lower surface bead 20 with respect to the inner surface of the downstream side exhaust pipe 3 is the height of the above embodiment. Contrary to the lower surface bead 10, it becomes higher toward the downstream side of the exhaust flow path. 6A is a cross-sectional view of the lower surface bead 30 formed in the downstream side exhaust pipe 6 of the second comparative example, and the height of the lower surface bead 30 with respect to the inner surface of the downstream side exhaust pipe 3 is constant.

  In each simulation result diagram, A indicates the upstream side of the exhaust flow path, and B indicates the downstream side of the exhaust flow path. Moreover, the direction of the arrow in each simulation result shows the flow direction of exhaust gas. That is, FIGS. 4A, 5B, and 6B are simulation results when the exhaust gas flows from the upstream side A to the downstream side B of the exhaust passage, and FIGS. 4B, 5C, and 6C are from the downstream side B to the upstream side A. It is a simulation result in case exhaust gas flows. Moreover, the speed of the flow of the exhaust gas in each simulation result is expressed by shading, and the portion where the concentration is high indicates that the flow of the exhaust gas is fast.

  Here, in each simulation result, from the speed of the exhaust gas when the exhaust gas flows from the upstream A to the downstream B, the speed of the exhaust gas when the exhaust gas flows from the downstream B to the upstream A The results of comparing the values minus are shown below. The reason why the exhaust gas flows from the downstream side B to the upstream side A is because the backflow may occur due to the pulsation of the exhaust gas.

This embodiment (FIGS. 4A and 4B) 20.0 m / s
First Comparative Example (FIGS. 5B and 5C) 7.6 m / s
Second Comparative Example (FIGS. 6B and 6C) 15.9 m / s
According to the said result, the value in this embodiment will be 20.0 m / s, and compared with the 1st and 2nd comparative example, exhaust gas will flow most easily to the downstream of an exhaust flow path. Further, since the condensed water flows through the exhaust passage along with the flow of the exhaust gas, the condensed water can easily flow downstream.

[2. effect]
According to the embodiment described above in detail, the following effects can be obtained.
(1a) In the exhaust pipe 3 on the downstream side of the exhaust system 100, the lower surface bead 10 is provided in the exhaust passage where the position along the vertical direction rises toward the downstream side. Therefore, compared with the configuration in which the lower surface bead 10 is not provided, the condensed water can be easily discharged to the outside of the exhaust passage.

  (1b) The plurality of lower surface beads 10 are arranged in pairs with a lowermost line C that is a line connecting the lowest points in the vertical direction on the inner surface of the downstream side exhaust pipe 3 interposed therebetween. According to such a configuration, the condensed water is easily accelerated between the lower surface beads 10 arranged in pairs. Therefore, according to the present embodiment, the condensed water can be easily raised from the upstream side to the downstream side of the exhaust passage, and can be easily discharged to the outside of the exhaust passage.

  (1c) The pair of lower surface beads 10 sandwiching the lowest line C are formed such that a gap sandwiching the lowest line C widens toward the downstream side of the exhaust passage. Therefore, according to the present embodiment, an effect of making it difficult for the condensed water to flow backward from the downstream side to the upstream side of the exhaust passage can be obtained.

  (1d) The height of the lower surface bead 10 with respect to the inner surface of the downstream side exhaust pipe 3 becomes lower toward the downstream side of the exhaust passage. Therefore, according to the present embodiment, it is possible to make it difficult for the flow of condensed water from the upstream side to the downstream side of the exhaust flow path to decline.

  (1e) The exhaust system 100 includes an upper surface bead 11 that is provided at least vertically above the inner surface of the downstream exhaust pipe 3 and projects inward from the inner surface of the downstream exhaust pipe 3. Therefore, according to the present embodiment, the exhaust gas flowing through the exhaust passage is accelerated by the upper surface bead 11 and guided downward in the vertical direction, so that the condensed water flow rate is also easily accelerated. For this reason, the condensed water can be easily raised from the upstream side to the downstream side of the exhaust passage, and can be easily discharged to the outside of the exhaust passage.

  In the present embodiment, the exhaust system 100 corresponds to an example of an exhaust device, the lower surface bead 10 and the upper surface bead 11 correspond to an example of an inner surface protrusion, and the lowest line C corresponds to an example of an inner surface line.

[3. Other Embodiments]
As mentioned above, although embodiment of this indication was described, it cannot be overemphasized that this indication can take various forms, without being limited to the above-mentioned embodiment.

  (2a) In the above embodiment, the innermost line that is a line along the axis of the exhaust pipe on the inner surface of the exhaust pipe is exemplified by the lowest line C that is a line connecting the lowest vertical points on the inner surface of the downstream exhaust pipe 3. However, the position of the inner surface line is not limited to this. For example, a line along the axis of the exhaust pipe on the side or upper side of the inner surface of the exhaust pipe may be used as the inner surface line. In other words, in the above embodiment, the lower surface bead 10 provided on the lower side in the vertical direction on the inner surface of the downstream side exhaust pipe 3 is exemplified as the inner surface protrusion, but the arrangement of the inner surface protrusion is limited to this. is not. For example, the inner surface protruding portion may be disposed on the side or upper side of the inner surface of the exhaust pipe. According to such a configuration, for example, the condensed water can be easily discharged even when the condensed water flows by centrifugal force other than the lower side in the vertical direction on the inner surface of the exhaust pipe. Therefore, the inner surface protruding portion may not be provided on the lower side in the vertical direction on the inner surface of the exhaust pipe, and the inner surface protruding portion may be provided only on a portion other than the lower side. A plurality of inner surface lines may exist.

  (2b) In the above-described embodiment, the configuration in which the lower surface bead 10 as the inner surface protrusion is arranged so as to be symmetric with respect to the lowermost line C as the inner surface line is exemplified, but the present invention is not limited to this. is not. For example, the inner surface protrusions may be arranged on the inner surface of the exhaust pipe so as to be asymmetrical, such as having different shapes and numbers on the left and right, and may not be disposed across the inner surface line. .

  (2c) In the above-described embodiment, the configuration in which the lower surface bead 10 is formed such that the height with respect to the inner surface of the downstream side exhaust pipe 3 becomes lower from the upstream side to the downstream side of the exhaust passage is exemplified. However, the configuration of the lower surface bead 10 is not limited to this. For example, the height of the lower surface bead 10 may be formed so as to increase from the upstream side to the downstream side of the exhaust flow path, or may be constant.

  (2d) In the above embodiment, the configuration in which the upper surface bead 11 is provided on the upper surface in the vertical direction on the inner surface of the downstream exhaust pipe 3 is exemplified, but the configuration of the downstream exhaust pipe 3 is not limited to this. . For example, the downstream exhaust pipe may be configured such that the upper surface bead 11 is not provided.

  (2e) In the above embodiment, the configuration in which the upper surface bead 11 is provided on the upper side in the vertical direction on the inner surface of the downstream side exhaust pipe 3 is exemplified, but the configuration of the upper surface bead 11 is not limited thereto. For example, the upper surface beads 11 may be provided on both the upper side and the side surface in the vertical direction.

  (2f) In the above embodiment, the upper surface beads 11 are arranged alternately with the lower surface beads 10 at the same constant intervals as the lower surface beads 10 along the axial direction of the downstream exhaust pipe 3. However, the position of the upper surface bead 11 is not limited to this. For example, the upper surface beads 11 may be arranged at a constant interval different from the lower surface beads 10. Further, for example, the upper surface beads 11 may not be arranged alternately with the lower surface beads 10.

  (2g) In the above embodiment, the inner surface protrusion is exemplified by a protrusion (bead) formed by being recessed from the outer surface of the downstream side exhaust pipe toward the inner surface. However, the configuration of the inner surface protrusion is limited to this. It is not a thing. For example, a separate protrusion may be provided on the exhaust pipe.

  (2h) The functions of one component in the above embodiment may be distributed as a plurality of components, or the functions of a plurality of components may be integrated into one component. Further, at least a part of the configuration of the above embodiment may be replaced with a known configuration having the same function. Moreover, you may abbreviate | omit a part of structure of the said embodiment as long as a subject can be solved. In addition, at least a part of the configuration of the above embodiment may be added to or replaced with the configuration of the other embodiment. In addition, all the aspects included in the technical idea specified from the wording described in the claims are embodiments of the present disclosure.

Claims (7)

An exhaust pipe having an exhaust flow path, the position along the vertical direction in the exhaust flow path rising toward the downstream side of the exhaust flow path,
An exhaust device comprising: an inner surface protrusion that is provided on an inner surface of the exhaust pipe and protrudes more inside the exhaust pipe than the inner surface. The exhaust device according to claim 1,
The exhaust device, wherein the plurality of inner surface protrusions are arranged in pairs across an inner surface line that is a line along the axis of the exhaust pipe on the inner surface. The exhaust device according to claim 2,
The pair of inner surface protrusions sandwiching the inner surface line is formed so that a gap sandwiching the inner surface line extends toward the downstream side of the exhaust channel. The exhaust device according to claim 2 or claim 3,
The height of the inner surface protrusion portion with respect to the inner surface becomes lower toward the downstream side of the exhaust passage. The exhaust device according to any one of claims 2 to 4,
The exhaust device is provided on the inner surface of the exhaust pipe at least on the lower side in the vertical direction. The exhaust device according to claim 5,
The inner surface line is an exhaust device that connects the lowest vertical points on the inner surface. The exhaust device according to any one of claims 1 to 6,
The inner surface protrusion is an exhaust device provided on an upper side in a vertical direction on an inner surface of the exhaust pipe.