JP2017115681A - Exhaust manifold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust manifold capable of suppressing the concentration of stress caused by the downstream side ends of exhaust pipes extended in the extending directions by heat.SOLUTION: The exhaust manifold includes a plurality of exhaust pipes and a confluent part, the confluent part including a first shell member, a second shell member, and a partition member, the partition member being provided between the first shell member and the second shell member for partitioning an internal flow path into a first confluent flow path on the side of the first shell member and a second confluent flow path on the side of the second shell member, the plurality of first-type exhaust pipes being inserted into the upstream side opening of the first confluent flow path in the confluent part, the plurality of second-type exhaust pipes being inserted into the upstream side opening of the second confluent flow path in the confluent part, the plurality of exhaust pipes including a plurality of exhaust pipes whose downstream side ends are different in extending direction from one another.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to an exhaust manifold.

  An exhaust manifold is known that includes a plurality of exhaust pipes that form exhaust passages from each cylinder of an internal combustion engine, and a merging portion that joins exhaust gases that have flowed out from the plurality of exhaust pipes. In Patent Document 1, the downstream end of each of the four exhaust pipes is processed into a cross-sectional shape obtained by dividing a circle into four parts, and the upstream of the merging part is overlapped so that the cross-section becomes a circular shape as a whole. A configuration inserted into a side opening is disclosed. Further, in this configuration, a flat partition plate protruding downstream from the exhaust pipe is provided between the downstream end of the two exhaust pipes and the downstream end of the other two exhaust pipes. It is done.

Japanese Patent No. 5014695

  However, in the configuration described in Patent Document 1 described above, since the extending directions of the downstream end portions of the four exhaust pipes are all the same (parallel), the downstream end portions of the respective exhaust pipes are extended in the extending direction by heat. There was a problem that stress due to elongation was applied in the same direction, and stress was easily concentrated.

  One aspect of the present disclosure aims to provide an exhaust manifold that can suppress stress concentration caused by the downstream end portion of the exhaust pipe extending in the extending direction due to heat.

  One aspect of the present disclosure is an exhaust manifold, which includes a plurality of exhaust pipes and a merging portion. The plurality of exhaust pipes form an exhaust passage from each cylinder of the internal combustion engine. The joining part forms an exhaust passage for joining exhaust gases that have flowed out from the plurality of exhaust pipes. The merge portion includes a first shell member, a second shell member, and a partition member. The second shell member forms an internal flow path with the first shell member. The partition member is provided between the first shell member and the second shell member, and the internal flow path includes the first merge flow path on the first shell member side and the second flow path on the second shell member side. It is divided into a merging channel. The plurality of exhaust pipes includes a plurality of first type exhaust pipes and a plurality of second type exhaust pipes. The plurality of first-type exhaust pipes are inserted into upstream openings of the first merge channel in the merge section. The plurality of second-type exhaust pipes are inserted into upstream openings of the second merging channel in the merging portion. The plurality of exhaust pipes include a plurality of exhaust pipes whose downstream end portions have different extending directions.

  In such a configuration, the plurality of exhaust pipes include a plurality of exhaust pipes having different downstream end portions in the extending direction. Therefore, compared to a configuration in which the downstream ends of all the exhaust pipes have the same extending direction, it is possible to suppress concentration of stress caused by the downstream ends of the exhaust pipe extending in the extending direction due to heat. .

  According to one aspect of the present disclosure, a flange portion having a surface parallel to the surface of the partition member is formed on each outer edge of the first shell member and the second shell member, and the partition member is a first shell member And it may be provided in a state of being sandwiched between the flange portions of the second shell member.

  According to such a structure, the 1st shell member and the 2nd shell member can be joined by joining each flange part of the 1st shell member and the 2nd shell member. For this reason, in the junction part of the 1st shell member and the 2nd shell member, it becomes difficult to produce the clearance gap which connects internal space and external space between the 1st shell member and the 2nd shell member. Therefore, for example, it is possible to make it difficult for foreign matter such as spatter when joined by welding to enter the internal space between the first shell member and the second shell member.

In one aspect of the present disclosure, the flange portion of the first shell member and the flange portion of the second shell member may have different external shapes.
According to such a configuration, the first shell member and the second shell member are compared with the configuration in which the outer shapes of the flange portion of the first shell member and the flange portion of the second shell member are the same. Can be easily joined.

1 is an overall view of an exhaust purification device of an embodiment. FIG. 2A is a diagram illustrating a state in which the first exhaust pipe and the fourth exhaust pipe are fitted to the first shell member. FIG. 2B is a diagram illustrating a state in which the partition member is overlaid on the first shell member. FIG. 2C is a diagram illustrating a state in which the second exhaust pipe and the third exhaust pipe are disposed on the opposite side of the first exhaust pipe and the fourth exhaust pipe with the partition member interposed therebetween. FIG. 2D is a diagram (overall view of the exhaust manifold) showing a state in which the second shell member is put on the second exhaust pipe and the third exhaust pipe. It is an exploded view of the exhaust manifold of other embodiments.

Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings.
[1. Constitution]
An exhaust emission control device 100 shown in FIG. 1 has an exhaust passage for guiding exhaust gas discharged from each of a plurality of (four in this example) cylinders of an internal combustion engine (not shown) of a vehicle. Form part. The exhaust purification device 100 includes an upstream flange 1, an exhaust manifold 2, an upstream cone 3, a catalyst case 4, a downstream cone 5, a tubular member 6, and a downstream flange 7.

  The upstream flange 1 is a metal plate-like member, and a plurality of (four in this example) through-holes functioning as exhaust ports for exhaust gas from each cylinder of the internal combustion engine are formed. Upstream end portions of four exhaust pipes 21 to 24 to be described later are connected to each through hole.

  The exhaust manifold 2 is composed of a plurality of metal members and is connected to the upstream flange 1. The exhaust manifold 2 forms an exhaust passage for joining exhaust gases flowing out from the cylinders of the internal combustion engine. Specifically, the exhaust manifold 2 collects four exhaust passages corresponding to four cylinders into two exhaust passages. The detailed configuration of the exhaust manifold 2 will be described later.

  The upstream cone 3 is a metal member having a shape in which the cross-sectional area of the exhaust passage gradually increases toward the downstream side, and is connected to the downstream end portion of the exhaust manifold 2. The upstream cone 3 and the exhaust manifold 2 form an exhaust flow path that joins exhaust gases flowing out from the cylinders of the internal combustion engine. Specifically, the upstream cone 3 aggregates the two exhaust passages after the aggregation in the exhaust manifold 2 into one exhaust passage.

The catalyst case 4 is a metal cylindrical member, and is connected to the downstream end of the upstream cone 3. The catalyst case 4 houses a columnar catalyst (not shown) for purifying exhaust gas.
The downstream cone 5 is a metal member having a shape in which the cross-sectional area of the exhaust passage gradually decreases toward the downstream side, and is connected to the downstream end of the catalyst case 4. The downstream cone 5 forms an exhaust passage for exhaust gas purified by the catalyst accommodated in the catalyst case 4.

The tubular member 6 is a metallic cylindrical member and is connected to the downstream end of the downstream cone 5. The tubular member 6 forms an exhaust passage for exhaust gas flowing out from the downstream cone 5.
The downstream flange 7 is a metal plate-like member. A through hole into which the tubular member 6 can be inserted is formed, and the downstream flange 7 is fixed to the tubular member 6 in a state of passing through the through hole. A part of the downstream flange 7 is fixed to the vehicle body side.

Next, a detailed configuration of the exhaust manifold 2 will be described. The exhaust manifold 2 includes four exhaust pipes 21 to 24 and a merging portion 25.
As shown in FIGS. 2A to 2D, the cross-sectional shapes of the downstream end portions of the four exhaust pipes 21 to 24 are not the same and are classified into a plurality of types. Specifically, the cross-sectional shapes of the downstream end portions of the first exhaust pipe 21 and the fourth exhaust pipe 24 located on both the left and right sides in the juxtaposed direction are the same, and both are shapes obtained by dividing the circle into two. On the other hand, the cross-sectional shapes of the downstream end portions of the second exhaust pipe 22 and the third exhaust pipe 23 located in the center in the juxtaposed direction are the same, and both are shapes obtained by dividing a circle into four.

  The merging portion 25 forms an exhaust passage for merging the exhaust gases flowing out from the four exhaust pipes 21 to 24. As shown in FIGS. 1 and 2A to 2D, the merging portion 25 includes a first shell member 251, a second shell member 252, and a partition member 253.

  As shown in FIG. 2A, the first shell member 251 is a plate-like member having a depression. In the present embodiment, the first shell member 251 is a member obtained by pressing a metal flat plate, and the recess is formed in the center. Two recesses 251a and 251b having a cross-sectional shape obtained by dividing a circle into two are formed in the vicinity of the upstream end of the first shell member 251.

  The second shell member 252 shown in FIGS. 1 and 2D is a plate-like member having a depression. In the present embodiment, the second shell member 252 is a member obtained by pressing a metal flat plate, like the first shell member 251, and the recess is formed at the center. The second shell member 252 forms an internal flow path with the first shell member 251. The upstream side of the recess formed in the second shell member 252 is substantially hemispherical.

  Flange portions 251c and 252c having surfaces parallel to the surface of the partition member 253 are formed on the outer edges of the first shell member 251 and the second shell member 252, respectively. Hereinafter, the flange portion 251c of the first shell member 251 is referred to as “first flange portion 251c”, and the flange portion 252c of the second shell member 252 is referred to as “second flange portion 252c”.

  The first flange portion 251c and the second flange portion 252c have different external shapes. Specifically, as shown in FIG. 2D, the outer shape of the first flange portion 251c is designed to be slightly larger than the outer shape of the second flange portion 252c.

  The partition member 253 is a metal flat plate member, and is provided between the first shell member 251 and the second shell member 252. The partition member 253 has an internal channel formed between the two shell members 251 and 252 as a first merge channel on the first shell member 251 side and a second merge on the second shell member 252 side. Divide into flow paths. As shown in FIG. 2D, the outer shape of the partition member 253 is substantially the same shape as the second flange portion 252c in a portion overlapping the second flange portion 252c. The partition member 253 is fixed in a state of being sandwiched between the flange portions 251c and 252c of the first shell member 251 and the second shell member 252. The partition member 253 has a function of suppressing exhaust interference between exhaust gas that merges in the first merge channel and exhaust gas that merges in the second merge channel.

  As shown in FIG. 2D, the first exhaust pipe 21 and the fourth exhaust pipe 24 are respectively inserted into the two upstream openings 254a and 254b of the first merge channel in the merge section 25. On the other hand, the second exhaust pipe 22 and the third exhaust pipe 23 are inserted into the upstream opening 254 c of the second joining flow path in the joining section 25.

  The upstream openings 254a and 254b of the first merging channel are configured by the depressions 251a and 251b of the first shell member 251 in a state where the first shell member 251 and the partition member 253 are joined. . On the other hand, the upstream opening 254c of the second merging channel is located between the upstream end of the second shell member 252 and the partition member 253 in a state where the second shell member 252 and the partition member 253 are joined. Formed.

  In the present embodiment, the four exhaust pipes 21 to 24 include exhaust pipes whose downstream end portions do not have the same extending direction. The extending direction of the downstream end here is the direction in which the downstream end extends, in other words, the flow direction of the exhaust gas. For example, when the downstream end has a shape that can define an axis, the extending direction is the direction of the axis. Examples of the shape that can define the axis include a shape having a columnar or cone-shaped outer shape, and a shape in which the cross-sectional shape is not similar to a cone but changes in a similar manner.

  In this embodiment, the extending directions of the second exhaust pipe 22 and the third exhaust pipe 23 are the same, but each of the second exhaust pipe 22 and the third exhaust pipe 23 is the first exhaust pipe 21. And the extending direction is not the same for any of the fourth exhaust pipes 24. Further, the extending directions of the first exhaust pipe 21 and the fourth exhaust pipe 24 are not the same.

Next, a method for manufacturing the exhaust manifold 2 will be described.
First, as shown in FIG. 2A, the downstream end of the first exhaust pipe 21 is fitted into the depression 251a of the first shell member 251, and the depression 251b of the first shell member 251 is fitted into the depression 251b. The downstream end of the fourth exhaust pipe 24 is fitted.

  Subsequently, as illustrated in FIG. 2B, the partition member 253 is overlaid on the first shell member 251. In the present embodiment, the outer shape of the first flange portion 251 c is larger than the outer shape of the partition member 253. Therefore, in a state where the partition member 253 is overlapped with the first flange portion 251c, a part of the first flange portion 251c protrudes from the partition member 253.

  Subsequently, as shown in FIG. 2C, the second exhaust pipe 22 and the third exhaust pipe 23 are provided on the opposite side of the first exhaust pipe 21 and the fourth exhaust pipe 24 with the partition member 253 interposed therebetween. Be placed. The downstream end portions of the second exhaust pipe 22 and the third exhaust pipe 23 are arranged adjacent to each other so that the downstream end portions are combined to form a shape divided into two.

  Subsequently, as shown in FIG. 2D, the second shell member 252 is put on the second exhaust pipe 22 and the third exhaust pipe 23. At this time, the second shell member 252 is disposed so that the outer edge of the second flange portion 252c and the outer edge of the partition member 253 coincide with each other in a portion overlapping the partition member 253.

  Thereafter, the first flange portion 251c, the partition member 253, and the second flange portion 252c are joined (welded in this example) while the partition member 253 is sandwiched, whereby the exhaust manifold 2 is manufactured. In this example, the first exhaust pipe 21 and the fourth exhaust pipe 24 and the second exhaust pipe 22 and the third exhaust pipe 23 are welded at different locations.

[2. effect]
According to the embodiment detailed above, the following effects can be obtained.
(1) According to the configuration of the present embodiment, it is possible to suppress stress concentration caused by the downstream end portions of the exhaust pipes 21 to 24 extending in the extending direction due to heat. That is, the use environment of the exhaust manifold is at a high temperature, and the exhaust manifold is required to have durability against repeated temperature changes. If the extension direction of the downstream end of all the exhaust pipes is the same, the load due to the downstream end of each exhaust pipe extending in the extension direction due to heat is applied in the same direction, and stress tends to concentrate. Become. In such a configuration, a reinforcing member or the like may be required in order to improve the durability of the exhaust manifold.

  On the other hand, in this embodiment, the exhaust pipes 21 to 24 include exhaust pipes whose downstream end portions do not have the same extending direction. Therefore, compared to a configuration in which the downstream ends of all the exhaust pipes have the same extending direction, it is possible to suppress concentration of stress caused by the downstream ends of the exhaust pipe extending in the extending direction due to heat. .

  (2) In the present embodiment, if all the downstream ends of the four exhaust pipes 21 to 24 are made to have the same extending direction, the downstream ends of the exhaust pipes 21 and 24 and the exhaust pipes 22 and 23 In order to align the stretching direction, the exhaust pipes 21 and 24 must be further bent. When the exhaust pipes 21 and 24 are further bent, the exhaust pipes 21 and 24 are correspondingly lengthened, and the exhaust manifold 2 occupies a larger space.

  On the other hand, in this embodiment, compared with the structure where the extending directions of the downstream end portions of the four exhaust pipes 21 to 24 are all the same, the processing costs are reduced because the exhaust pipes 21 and 24 are not bent. In addition, the exhaust manifold can be made compact.

  (3) Generally, the output flow of the plurality of exhaust gases from the cylinders of the internal combustion engine to the merging portion, in other words, the output of the internal combustion engine is improved as the lengths of the plurality of exhaust pipes are equal to each other. In the configuration in which all the extending directions of the downstream end portions of the exhaust pipes 21 to 24 are not aligned as in the present embodiment, the degree of freedom in design is higher than that in the configuration in which all the extending directions of the downstream end portions are the same. Since it is high, it is easy to match the length of the exhaust pipes 21 to 24. Therefore, it is possible to more easily improve the output of the internal combustion engine by matching the lengths of the exhaust pipes 21 to 24 as compared with the configuration in which all the downstream end portions have the same extending direction.

  (4) In the present embodiment, the first shell member 251 and the second shell member 252 are joined by joining the flange portions 251c and 252c of the first shell member 251 and the second shell member 252, respectively. Are joined. For this reason, in the joint part of the 1st shell member 251 and the 2nd shell member 252, the clearance gap which connects the internal space and external space between the 1st shell member 251 and the 2nd shell member 252 is formed. It becomes difficult to occur. Therefore, for example, it is possible to make it difficult for foreign matter such as spatter to enter the internal space between the first shell member 251 and the second shell member 252.

  In addition, this makes it possible to prevent foreign matter from being sucked into the internal combustion engine due to the negative pressure generated in the exhaust manifold 2 and causing the internal combustion engine to fail or stop functioning. Furthermore, when this embodiment is configured to include EGR (Exhaust Gas Recirculation), it is possible to suppress foreign matter from being caught in a valve in a path returning from the merging portion 25 to the internal combustion engine.

  (5) In the present embodiment, the first flange portion 251c and the second flange portion 252c have different external shapes. Specifically, the outer shape of the first flange portion 251c is slightly larger than the outer shape of the second flange portion 252c. Therefore, the first shell member 251 and the second shell member 252 can be easily joined as compared with the configuration in which the outer shapes of the first flange portion and the second flange portion are the same.

  In the present embodiment, the first exhaust pipe 21 and the fourth exhaust pipe 24 correspond to an example of the first type exhaust pipe, and the second exhaust pipe 22 and the third exhaust pipe 23 are the second type. This corresponds to an example of the exhaust pipe.

[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.

  (1) Although the said embodiment was illustrated as a structure in which the several exhaust pipe which forms the exhaust flow path from each cylinder of an internal combustion engine contains the several exhaust pipe from which the extension direction of a downstream end part mutually differs, The configuration is not limited to the above embodiment. For example, the exhaust manifold 8 shown in FIG. 3 includes four exhaust pipes 81 to 84, a first shell member 851, a second shell member 852, and a partition member 853. In this configuration, the extending directions of the downstream ends of the plurality of exhaust pipes 81 to 84 are all different, and there are no exhaust pipes having the same extending direction of the downstream ends. That is, even in this configuration, the extending direction of the downstream end portion of at least one exhaust pipe is not parallel to the extending direction of the downstream end portion of the other at least one exhaust pipe. In addition, the cross-sectional shape of the downstream end part of the four exhaust pipes 81 to 84 is a shape obtained by dividing a circle into two parts. According to the exhaust manifold 8 having such a configuration, stress concentration can be further suppressed.

  (2) In the above embodiment, the exhaust manifold 2 has the four exhaust pipes 21 to 24, but the number of exhaust pipes that the exhaust manifold has is not limited to this. The exhaust manifold may have, for example, five or more exhaust pipes.

  (3) The shape of each member of the exhaust purification device 100 is not limited to that of the above embodiment. For example, in the said embodiment, although the structure where the external shape of a partition member was the same as the external shape of one flange part was illustrated, the shape of a partition member is not restricted to this. For example, the outer shape of the partition member may be larger than the outer shape of one flange portion and smaller than the outer shape of the other flange portion. That is, the 1st flange part, a partition member, and the 2nd flange part may be the structure on which this step is piled up in this order.

  In the above embodiment, the first flange portion 251c and the second flange portion 252c have different outer shapes. However, the outer shape of the flange portion is not limited to this, and the first flange portion and the second flange portion are not limited thereto. The part may have the same outer shape.

  (4) 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. Moreover, you may abbreviate | omit a part of structure of the said embodiment. 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.

  DESCRIPTION OF SYMBOLS 1 ... Upstream flange, 2, 8 ... Exhaust manifold, 3 ... Upstream cone, 4 ... Catalyst case, 5 ... Downstream cone, 6 ... Tubular member, 7 ... Downstream flange, 21-24, 81-84 ... Exhaust Pipe, 25 ... Merging portion, 100 ... Exhaust gas purification device, 251,851 ... First shell member, 251a, 251b ... Depression, 251c, 252c ... Flange portion, 252,852 ... Second shell member, 253,853 ... Partition members, 254a, 254b ... upstream opening of the first merging channel, 254c ... upstream opening of the second merging channel.

Claims (3)

A plurality of exhaust pipes forming an exhaust passage from each cylinder of the internal combustion engine;
A merging portion for forming an exhaust passage for merging the exhaust gases flowing out from the plurality of exhaust pipes;
With
The junction is
A first shell member;
A second shell member forming an internal flow path with the first shell member;
The first shell member and the second shell member are provided between the first shell member and the second shell member, and the internal flow path is a first merge flow path on the first shell member side and a second on the second shell member side. A partition member that is divided into a merging flow path of
With
The plurality of exhaust pipes include a plurality of first type exhaust pipes and a plurality of second type exhaust pipes,
The plurality of first-type exhaust pipes are inserted into upstream openings of the first merge channel in the merge section,
The plurality of second-type exhaust pipes are inserted into upstream openings of the second merging channel in the merging portion,
The exhaust manifold, wherein the plurality of exhaust pipes includes a plurality of exhaust pipes having different downstream end portions in extending directions. The exhaust manifold according to claim 1,
A flange portion having a surface parallel to the surface of the partition member is formed on each outer edge of the first shell member and the second shell member,
The partition member is an exhaust manifold provided in a state of being sandwiched between the flange portions of the first shell member and the second shell member. An exhaust manifold according to claim 2,
An exhaust manifold in which the flange portion of the first shell member and the flange portion of the second shell member have different external shapes.