JP4083966B2 - Manifold converter and front tube connection structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a connection structure between a manifold converter mounted on a vehicle exhaust system and a front tube.
[0002]
[Prior art]
Conventionally, in an exhaust system of a vehicle, an exhaust manifold that sends exhaust gas discharged from each cylinder of the engine into a single silencer is mounted on the cylinder head of the engine. Recently, the weight reduction, high heat resistance, etc. Therefore, stainless steel exhaust manifolds are widely used instead of cast iron exhaust manifolds.
[0003]
Conventionally, a catalytic converter for purifying harmful components such as CO in exhaust gas has been mounted under the vehicle floor in a vehicle exhaust system. However, in recent years, instead of such a catalytic converter, Japanese Utility Model Laid-Open No. 6-80815 is disclosed. In many vehicles, a so-called manifold converter is mounted directly on the exhaust manifold.
By the way, as described above, the exhaust manifold collects exhaust gas discharged from each cylinder of the engine into one silencer and sends it to the silencer. By collecting the exhaust gas, the cylinders interfere with each other and the exhaust gas flows backward. It happens that the flow becomes worse. This is exhaust interference, and this phenomenon simultaneously increases the pressure of the exhaust and applies pressure to the exhaust on the cylinder side, resulting in resistance of the exhaust gas coming out of the engine and a loss of output.
[0004]
Therefore, for example, in a 4-cylinder exhaust manifold, for the purpose of preventing exhaust interference, the so-called so-called four branch pipes 1, 3, 5, and 7 are grouped together as shown in FIGS. A dual type exhaust manifold 9 is known, and accordingly, two manifold converters 11 and 13 are attached to two exhaust gas passages of the two exhaust manifold 9. As shown in the figure, the diffuser (collecting pipe) 15 on the downstream side of the manifold converters 11 and 13 is also used as the diffuser of both the manifold converters 11 and 13, and is connected to the diffuser 15 as shown in FIGS. A front tube 21 is connected via a flange 17 and a spherical joint 19.
[0005]
In addition, on the upstream side of the diffuser 15 and the front tube 21, partition plates 23 and 25 are arranged to face each other in order to prevent exhaust interference, and the exhaust gas G flowing down one manifold converter 11 is separated from the partition plate. The exhaust gas G guided to the downstream side of the front tube 21 through one exhaust gas flow path 27 partitioned by 23, 25 and flowing down the other manifold converter 13 is the other partitioned by the partition plates 23, 25. The exhaust gas passage 29 is led to the downstream side of the front tube 21.
[0006]
Thus, as shown in FIG. 6, the partition plate 23 mounted in the diffuser 15 is formed in a circular arc shape at the front end side and protrudes toward the front tube 21. The exhaust gas upstream end is cut out in an arc shape so that it does not interfere with the partition plate 23 even when the spherical joint 19 slides, and a gap 31 is formed between the front tube 21 and the partition plate 23. It is assembled inside.
[0007]
In addition, in FIG. 6, 33 is a seal bearing.
[0008]
[Problems to be solved by the invention]
However, conventionally, the partition plate 23 on the diffuser 15 side and the partition plate 25 on the front tube 21 side are set to the same thickness as shown in FIG. There is a risk that the partition plates 23 and 25 may be displaced as shown in FIG. 8 due to variations during assembly.
[0009]
And if the partition plates 23 and 25 are displaced in this manner, it has been pointed out that the exhaust gas G in the exhaust gas flow paths 27 and 29 interferes with each other and the engine output decreases.
Further, as described above, the gap 31 is formed between the partition plate 23 and the partition plate 25 to prevent mutual interference. If the gap 31 is too wide, as shown in FIG. In addition, the exhaust gas G in the exhaust gas flow paths 27 and 29 interferes with each other and the engine output is reduced.
[0010]
Furthermore, as described above, the partition plate 25 has an exhaust gas upstream side end corresponding to the tip shape of the partition plate 23, but the partition plate 25 conventionally has an unprocessed partition plate at the front. After setting in the tube 21, the partition plate is cut into an arc shape by a rotating roller or the like (not shown) and post-processed.
However, if the exhaust gas upstream side end of the partition plate 25 is cut to the edge of the tube wall 21a of the front tube 21 so as to follow the tip shape of the partition plate 23 formed in an arc shape as shown in FIG. There was a possibility that the pipe wall a would be cut by mistake.
[0011]
The present invention has been devised in view of such circumstances, and in connecting the diffuser and the front tube as described above, a manifold converter that prevents interference between exhaust gases flowing down each exhaust gas flow path partitioned by a partition plate; It aims at providing the connection structure of a front tube.
[0012]
[Means for Solving the Problems]
In order to achieve such an object, the invention according to claim 1 is characterized in that a partition plate for preventing exhaust interference is provided in the diffuser of the manifold converter and the front tube connected to the diffuser via a spherical joint. In the connection structure of the manifold converter and the front tube which are opened and opposed to each other, the diffuser side partition plate is made thicker than the front tube side partition plate.
[0013]
In the invention according to claim 2, the partition plate for preventing the exhaust interference is disposed opposite to the diffuser of the manifold converter and the inside of the front tube connected to the diffuser via a spherical joint. In the connection structure of the manifold converter and the front tube, an arc-shaped notch is formed at the exhaust gas upstream end of the front tube side partition plate, leaving the tube wall side of the front tube, and the diffuser side partition is formed. Arc-shaped projecting pieces projecting along the notches are formed on the plate, and projecting parts projecting toward the partition plate of the front tube are obstructed in sliding of the spherical joint at both hem portions of the projecting pieces. It was established without coming.
[0014]
The invention according to claim 3 is characterized in that, in the connection structure of the manifold converter and the front tube according to claim 2, the projecting pieces and the projecting parts provided at both hem parts thereof are connected in an arc shape. And
[0015]
(Function)
According to the first aspect of the invention, since the thickness of the diffuser side partition plate is larger than the front tube side partition plate, the exhaust gas flowing down from the diffuser side is exhaust gas upstream of the front tube side partition plate. The flow is not disturbed by hitting the end, and even if the partition plate is displaced due to variations in both partition plates or during assembly, the diffuser side partition plate absorbs the displacement of the partition plate due to variations and exhausts. Interference will be prevented.
[0016]
And according to the invention concerning Claim 2 and Claim 3, a protrusion part will prevent the exhaust interference by the clearance gap with the partition plate by the side of a front tube.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0018]
In addition, the same thing as the prior art example shown in FIG. 4 and the same is attached | subjected the same code | symbol, and those structural description is abbreviate | omitted.
1 and 2 show an embodiment of a connection structure according to claim 1, in which 35 and 37 are opposed to the diffuser 15 and the front tube 21, respectively, like the partition plates 23 and 25 of FIG. The exhaust gas G that has flowed down through one manifold converter 11 by the arranged partition plate for preventing interference with the exhaust gas is guided to the downstream side of the front tube 21 through one exhaust gas passage 27 partitioned by the partition plates 35 and 37. Further, the exhaust gas G flowing down the other manifold converter 13 is guided to the downstream side of the front tube 21 through the other exhaust gas passage 29 partitioned by the partition plates 35 and 37.
[0019]
Although not shown, the partition plate 35 on the diffuser 15 side, like the partition plate 23, is formed in a circular arc shape on the entire front end side and protrudes toward the front tube 21. On the other hand, the exhaust gas of the partition plate 37 correspondingly corresponds to this. Similarly to the partition plate 25, the upstream end is notched in an arc shape so that it does not interfere with the partition plate 35 even when the spherical joint 19 slides, and a gap 39 is formed between the upstream end portion and the partition plate 35. In this embodiment, the thickness t1 of the partition plate 35 on the diffuser 15 side is set to 4.0 mm in addition to the conventional configuration as described above, and the front tube 21 is assembled in the front tube 21. The plate thickness t2 of the partition plate 37 on the tube 21 side is 2.0 mm, and the plate thickness t1 of the partition plate 35 is twice the plate thickness t2 of the partition plate 37.
[0020]
Since the present embodiment is configured as described above, the exhaust gas G flowing down one manifold converter 11 passes through one exhaust gas flow path 27 partitioned by the partition plates 35 and 37 as described above, and the front tube 21. Further, the exhaust gas G that has flowed down the other manifold converter 13 is guided to the downstream side of the front tube 21 through the exhaust gas passage 29 partitioned by the partition plates 35 and 37. Since the plate thickness t1 of 35 is larger than the plate thickness t2 of the partition plate 37, the exhaust gas G flowing down from the diffuser 15 side does not hit the exhaust gas upstream end of the partition plate 37 and the flow is not disturbed.
[0021]
Further, even if the partition plates 35 and 37 are displaced due to variations in both the partition plates 35 and 37 and variations during assembly, the plate thickness t1 of the partition plate 35 is set to twice the plate thickness t2 of the partition plate 37. Therefore, as shown in FIG. 2, the displacement of the partition plate 35 from the partition plate 37 due to variations in the thickness t1 of the partition plate 35 is absorbed, and interference between the exhaust gases G flowing down the exhaust gas flow paths 27 and 29 is prevented.
[0022]
Thus, according to this embodiment, exhaust interference due to variations in the partition plates 35 and 37 is eliminated, and the exhaust gas G flowing down from the diffuser 15 side hits the exhaust gas upstream end of the partition plate 37 and the flow is disturbed. Therefore, it is possible to prevent a decrease in engine output as compared with the conventional example shown in FIG.
FIG. 3 shows an embodiment of the connection structure according to claim 2 and claim 3, and this embodiment will be described below with reference to the drawings. The configuration excluding the invention part is the same as the conventional example shown in FIG. Therefore, even in the present embodiment, the same components as those in the conventional example are denoted by the same reference numerals, and the description of their structures is omitted.
[0023]
In the figure, 41 is a partition plate mounted in the front tube 21 as in the partition plate 25 described above. As in the conventional case, the partition plate 41 is formed after an unprocessed partition plate is set in the front tube 21. In this embodiment, the notch 43 is provided by scraping the upstream end of the upstream roller with a rotating roller or the like (not shown). In this embodiment, when the notch 43 is provided, the tube wall 21a of the front tube 21 is provided. As shown in the figure, the tube wall 21a side of the front tube 21 is left unprocessed, and a flat portion 45 that is flush with the tube wall 21a is formed at the site. .
[0024]
On the other hand, a partition plate 47 is also mounted on the diffuser 15 side so as to face the partition plate 41. In order to prevent interference with the partition plate 41 due to the sliding of the spherical joint 19 and to prevent the exhaust interference by reducing the gap 49 with the partition plate 41, An arc-shaped protruding piece 51 protruding along the notch 43 is formed. If the protruding piece 51 is provided on the entire front end side of the partition plate 47 as shown by a two-dot chain line in FIG. There is a possibility that a large gap 49 is formed between the flat portion 45 of the plate 41 and exhaust interference occurs.
[0025]
Therefore, as shown in the figure, in the present embodiment, the gap 49 between the flat portion 45 is reduced as much as possible, and it does not interfere with the sliding of the spherical joint 19, so that it does not interfere with both hem portions of the protruding piece 51. In addition, a substantially triangular projecting portion 53 projecting in the direction of the flat portion 45 of the partition plate 41 is provided. The projecting portion 53 and the projecting piece 51 are connected in an arc shape, and a corner portion 55 of the projecting portion 53 is provided. Is formed with a round (arm).
[0026]
Since the present embodiment is configured as described above, the exhaust gas G flows down from the manifold converters 11 and 13 to the front tube 21 through the exhaust gas passages 27 and 29 partitioned by the partition plates 41 and 47. .
And as above-mentioned, in this embodiment, in order to prevent cutting the pipe wall 21a of the front tube 21 accidentally at the time of the process of the notch 43, the pipe wall 21a side of the front tube 21 is left unprocessed. Therefore, the protrusion 53 is provided for the purpose of reducing the gap 49 between the flat part 45 and the partition plate 47 as much as possible, and the protrusion 53 prevents exhaust interference due to the gap 49 with the flat part 45. To prevent.
[0027]
Therefore, according to the present embodiment, exhaust interference caused by the gap 49 between the partition plates 41 and 47 is eliminated while solving the conventional problem that the pipe wall 21a of the front tube 21 is accidentally shaved when the partition plate 41 is processed. This has made it possible to prevent a decrease in engine output.
[0028]
【The invention's effect】
As described above, according to the first aspect of the present invention, exhaust interference due to variations in partition plates is eliminated, and exhaust gas flowing down from the diffuser side flows against the exhaust gas upstream end of the front tube side partition plate. Therefore, the engine output can be prevented from decreasing.
[0029]
Further, according to the inventions according to claim 2 and claim 3, while eliminating the conventional problem that the pipe wall of the front tube is accidentally shaved when the partition plate is processed, exhaust interference due to the gap between the partition plates is prevented. This has made it possible to prevent a decrease in engine output.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a connection structure according to an embodiment of the present invention corresponding to a BB cross section of FIG.
2 is a cross-sectional view taken along line II-II in FIG.
3 is a cross-sectional view of a connection structure according to an embodiment of claims 2 and 3 corresponding to the AA cross section of FIG. 4;
FIG. 4 is a front view of a conventional exhaust manifold equipped with a manifold converter.
5 is a side view of the exhaust manifold shown in FIG. 4. FIG.
6 is a cross-sectional view taken along line AA in FIG.
7 is a cross-sectional view taken along line BB in FIG.
FIG. 8 is a cross-sectional view of a connection portion between a conventional diffuser and a front tube showing a state in which a partition plate is displaced.
FIG. 9 is an enlarged cross-sectional view of a connection portion between a conventional diffuser and a front tube showing exhaust interference.
[Explanation of symbols]
15 Diffuser 21 Front tube 35, 37, 41, 47 Partition plate 43 Notch 45 Flat part 51 Projection piece 53 Projection part

Claims (3)

A partition plate (35) for preventing exhaust interference is provided in the diffuser (15) of the manifold converter (11, 13) and the front tube (21) connected to the diffuser (15) via a spherical joint (19). , 37) with a gap (39) therebetween and facing the manifold converter (11, 13) and the front tube (21),
The manifold converter and front tube connection structure, wherein the diffuser (15) side partition plate (35) is made thicker than the front tube (21) side partition plate (37). An exhaust interference prevention partition plate (47) is provided inside the diffuser (15) of the manifold converter (11, 13) and the front tube (21) connected to the diffuser (15) via a spherical joint (19). , 41) with a gap (49) opened and facing the manifold converter (11, 13) and the front tube (21),
An arc-shaped notch (43) is formed at the exhaust gas upstream end of the front tube (21) side partition plate (41), leaving the tube wall (21a) side of the front tube (21),
The partition plate (47) on the diffuser (15) side is formed with an arc-shaped projecting piece (51) projecting along the notch (43), and at both hems of the projecting piece (51), Connection between the manifold converter and the front tube, characterized in that the protrusion (53) protruding in the direction of the partition plate (41) of the tube (21) is provided without hindering the sliding of the spherical joint (19). Construction. The connection structure of a manifold converter and a front tube according to claim 2, wherein the projecting piece (51) and the projecting portions (53) provided at both hem portions thereof are connected in an arc shape.

Images