JP2019031964A5

JP2019031964A5 -

Info

Publication number: JP2019031964A5
Application number: JP2017154981A
Authority: JP
Filing date: 2017-08-10
Publication date: 2020-08-13
Anticipated expiration: 2037-08-10

Description

また、本実施例のエンジン１の排気構造によれば、仕切壁２１が、排気フランジ部１６から外方に直線状に延びる第１の仕切壁部２１Ａと、第１の仕切壁部２１Ａから下方に湾曲する第２の仕切壁部２１Ｂと、第２の仕切壁部２１Ｂから下方に直線状に延びる第３の仕切壁部２１Ｃとを含んで構成されている。 Further, according to the exhaust structure of the engine 1 of the present embodiment, the partition wall 21 includes the first partition wall portion 21A that extends linearly outward from the exhaust flange portion 16 and the lower portion from the first partition wall portion 21A. It is configured to include a second partition wall portion 21B that is curved in an upward direction, and a third partition wall portion 21C that linearly extends downward from the second partition wall portion 21B.

このようにすれば、排気管８の温度が過度に上昇することを防止できる。具体的には、第１の仕切壁部２１Ａは、第１の排気口１４Ａおよび第２の排気口１４Ｂに近く、排気管８の中で最も高温の排気ガスに晒される部位である。 By doing so, it is possible to prevent the temperature of the exhaust pipe 8 from rising excessively. Specifically , the first partition wall portion 21A is a portion near the first exhaust port 14A and the second exhaust port 14B and exposed to the hottest exhaust gas in the exhaust pipe 8.

Claims

A cylinder block having a plurality of cylinders arranged side by side in a row, a cylinder head provided in an upper portion of the cylinder block, in which an exhaust passage for discharging exhaust gas from the cylinder is formed, and an arrangement of the cylinders. An exhaust pipe installed on a side surface of the cylinder block and the cylinder head along a direction, and an exhaust flange portion protruding outward from the side surface of the cylinder head, to which the exhaust pipe is connected,
The exhaust passage is provided for each cylinder, the exhaust passage portion through which exhaust gas discharged from the cylinder flows, and the exhaust flange portion downstream of the exhaust passage portion are provided with at least two exhaust passages. At least two exhaust collecting portions for collecting passages for each of the cylinders, and exhaust gas flowing through the exhaust collecting portions that communicate with the exhaust collecting portions and open to the exhaust flange portion. With at least two exhaust ports that exhaust to the outside of the
A second exhaust port, wherein the exhaust port constitutes at least one of the at least two exhaust ports, and a second exhaust port which constitutes at least one of the at least two exhaust ports. The exhaust structure of an internal combustion engine that constitutes the exhaust port of
The exhaust pipe is partitioned by a partition wall, and a first exhaust pipe passage through which the exhaust gas discharged from the first exhaust port flows and a second exhaust gas passage through which the exhaust gas discharged from the second exhaust port flows. With an exhaust pipe passage,
The exhaust structure of an internal combustion engine, wherein the partition wall has a plate thickness that gradually decreases toward the downstream side in the exhaust gas flow direction.

The second exhaust port is formed below the first exhaust port,
The exhaust pipe includes a linear portion extending linearly outward from the exhaust flange portion, bent downward from the straight portion, the side surface of the curved inner surface facing the side surface of the cylinder block said cylinder block And a curved portion having a curved outer side surface located on the opposite side,
In the axial direction orthogonal to the axis of the cylinder, the bending portion has a tip in a direction in which the axis of the cylinder and the outside surface of the cylinder extend with respect to a maximum distance at which the bending outer surface and the axis of the cylinder are most distant from each other. The exhaust structure for an internal combustion engine according to claim 1, wherein the exhaust structure is curved so that a distance to the portion is shortened.

A catalytic converter connected to the downstream end of the exhaust pipe, and provided in the catalytic converter,
Equipped with an exhaust sensor that detects the amount of oxygen in the exhaust gas,
The first exhaust pipe passage is formed above the second exhaust pipe passage and outward from the side surface of the cylinder head with respect to the second exhaust pipe passage.
The exhaust gas of the internal combustion engine according to claim 1 or 2, wherein the exhaust sensor is installed on the partition wall side, facing the downstream opening end of the first exhaust pipe passage. Construction.

The partition wall includes a first partition wall portion that extends linearly outward from the exhaust flange portion, a second partition wall portion that curves downward from the first partition wall portion, and the second partition wall. And a third partition wall portion that extends linearly downward from the wall portion,
The plate thickness of the second partition wall portion is formed larger than the plate thickness of the first partition wall portion, and the plate thickness of the third partition wall portion is larger than that of the second partition wall portion. The exhaust structure for an internal combustion engine according to any one of claims 1 to 3, wherein the exhaust structure is formed to have a thickness smaller than a plate thickness.

Wherein at least one of the first exhaust pipe passage and the second exhaust pipe passage, one of claims 1 to 3, characterized in that the opening area of the downstream side is larger to the upstream side 2. An exhaust structure for an internal combustion engine according to item 1.

The exhaust structure for an internal combustion engine according to claim 4, wherein the partition wall has a through hole from the first partition wall portion to the second partition wall portion.

7. The opening area of the through hole formed in the second partition wall portion is larger than the opening area of the through hole formed in the first partition wall portion. Exhaust structure of internal combustion engine.