JP6901380B2 - Water collection chamber for exhaust pipe for internal combustion engine - Google Patents

Description

The present invention relates to an exhaust pipe for an internal combustion engine mounted on a vehicle, and particularly to a water collecting chamber in which condensed water collects.

A vehicle equipped with an internal combustion engine has an exhaust pipe for exhausting the exhaust gas of the internal combustion engine. A catalytic converter and a muffler are provided in the middle of the exhaust pipe. In a typical vehicle with an internal combustion engine mounted on the front of the vehicle, the exhaust pipe passes under the vehicle body and extends rearward. At this time, the exhaust pipe moves up and down depending on the convenience of arrangement, such as avoiding other structures arranged in the lower part of the vehicle body. Water in which water vapor contained in the exhaust is condensed may collect inside the lower part of the exhaust pipe that goes up and down.

In Patent Document 1 below, exhaust is performed in the section from the rear end of the exhaust pipe (horizontal portion 22C of the center pipe) to the portion extending to the muffler (rear muffler 26) located high (horizontal portion 24B of the inlet pipe). A partition member (36) for partitioning the inside of the pipe into upper and lower parts is provided. In the section where the partition member (36) is provided, the upper portion and the lower portion of the exhaust pipe are blocked by the partition plate (36), and the flow of the upper portion and the flow of the lower portion are independent. The water collected in the lower portion of the exhaust pipe is discharged through the lower portion of the partition plate (36) by the exhaust flow of the internal combustion engine.

Japanese Unexamined Patent Publication No. 2015-158149

If a partition plate that completely divides the inside of the exhaust pipe into upper and lower parts is provided in the exhaust pipe, the flow path through which the exhaust gas passes is limited when water collects, and the back pressure of the internal combustion engine may increase.

An object of the present invention is to suppress an increase in back pressure when water collects in a portion of an exhaust pipe where water collects.

The water collecting chamber of the exhaust pipe for an internal combustion engine according to the present invention, that is, a portion where aggregated water collects in the exhaust pipe is arranged in an outer shell member forming a pipeline through which exhaust gas flows and an outer shell member. It has a partition plate that partitions the inside of the member up and down. The partition plate is joined to the outer shell member at the left and right side edges of the upstream end and the downstream end, and the left and right side edges and the outer shell are formed at least in a part of the intermediate portion between the upstream end and the downstream end. A gap is provided between the members. Further, the partition plate has a descending portion that gradually descends toward the upstream side as it goes downstream, and has a horizontal portion that extends horizontally near the center of the height of the outer shell member on the downstream side following the descending portion. Also, it has a rising part that rises further downstream as it goes downstream, following the horizontal part. Further, the above-mentioned gap is provided between a part of the descending portion and the outer shell member, and between a part of the ascending portion and the outer shell member.

By providing a gap between the outer shell member and the side edge of the partition plate, the space above and the space below the partition plate communicate with each other, and when water collects, part of the exhaust gas passes through the gap and is on the lower side. Flows upward from. As a result, an increase in back pressure can be suppressed.

It is a figure which shows the main part composition of the exhaust system of a vehicle. It is a side view of the water collection chamber which see through the inside. It is a top view and a cross-sectional view of a water collection chamber which sees through the inside. It is a figure explaining the function of the water collection chamber.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an exhaust system of an internal combustion engine mounted on a vehicle. In FIG. 1, the left side is the front of the vehicle when mounted on the vehicle, and the upper side is the upper side of the vehicle. The front end of the exhaust pipe 10 is connected to an internal combustion engine (not shown) mounted on the front portion of the vehicle, and the exhaust of the internal combustion engine is guided to the rear end of the vehicle and discharged from there. A catalytic converter 12, a sub muffler 14, and a main muffler 16 are provided in the middle of the path of the exhaust pipe 10. The catalytic converter 12 reduces harmful components in the exhaust gas by oxidizing and reducing them. Further, the sub muffler 14 and the main muffler 16 lower the temperature and pressure of the high-temperature and high-pressure exhaust gas to suppress noise. In the following description, the terms "upstream" and "downstream" refer to upstream and downstream with respect to the direction of exhaust flow.

The exhaust pipe 10 moves up and down for convenience of arrangement such as avoiding other structures of the vehicle. For example, it is placed at a low position below the floor of the passenger compartment or below the fuel tank, and is placed at a relatively high position around the rear axle in order to avoid the lower arm of the suspension and the axle beam. Therefore, the exhaust pipe 10 is once arranged at a low position in the flow direction of the exhaust, and then is arranged at a high position, during which an upward slope is formed.

The exhaust of an internal combustion engine contains water vapor generated by burning fuel, and when it is cooled in the exhaust pipe, it condenses into water. If the exhaust pipe 10 is arranged so as to gradually decrease toward the rear end, the water in the exhaust pipe 10 is discharged from the rear end. However, as described above, the exhaust pipe 10 has a portion arranged lower than the other portions in the middle, and water collects and collects in this portion. In the exhaust pipe 10, a water collecting chamber 18 is provided slightly upstream of the main muffler 16, and water collects there. The water collecting chamber 18 adopts a structure in which the collected water is sent out by utilizing the flow and pressure of the exhaust gas. The water sent out from the water collecting chamber 18 goes up the inclination of the exhaust pipe 10 and is sent to the main muffler 16, and is further discharged from the rear end opening of the exhaust pipe 10.

FIG. 2 is a view of the water collecting chamber 18 as viewed from the side of the vehicle in a state of being mounted on the vehicle, and the outer members are shown through so that the internal structure can be seen. FIG. 3 is a view in which (a) is viewed from above the vehicle, and (b), (c), and (d) are lines AA, BB, and CC shown in (a). It is a cross-sectional view by. In FIG. 3A, the outer member is shown through so that the internal structure can be seen. The water collecting chamber 18 is arranged inside the outer shell member 20 and the outer shell member 20 which forms a conduit as a part of the exhaust pipe 10, and is a partition plate 22 which divides the internal space of the outer shell member 20 into upper and lower parts. including.

The outer shell member 20 has a substantially cylindrical shape at the upstream end, and can be joined to the exhaust pipe 10 of the circular pipe upstream of the water collecting chamber 18. Further, the downstream end portion also has a substantially cylindrical shape. The outer shell member 20 has a flat shape that spreads in the lateral direction in the intermediate portion between the upstream side end portion and the downstream side end portion, and the downstream side portion is inclined upward. The outer shell member 20 has an upper outer shell 24 forming a ceiling surface and a lower outer shell 26 forming a bottom surface and a side surface, and on the side surface, the upper outer shell 24 and the lower outer shell 26 are welded or the like. It is formed by joining by a method.

In the partition plate 22, the side edge of the partition plate 22 is joined to the upper outer shell 24 at the upstream end and the downstream end. Specifically, the partition plate 22 is welded in the shaded areas (hereinafter referred to as welded areas) W1 and W2 in FIG. 3A and fixed to the upper outer shell 24. The side edge between the welding regions W1 and W2 on the upstream side and the downstream side of the partition plate 22 is located so as to form a gap 28 with the upper outer shell 24. The gap 28 may be formed in the entire portion between the welding regions W1 and W2 on the upstream side and the downstream side, or may be formed in a part thereof.

As shown in FIG. 2, the partition plate 22 is close to the upper outer shell 24 at the upstream end, and gradually descends toward the lower outer shell 26 as it goes downstream, and the outer shell member. When it reaches the vicinity of the center in the height direction of 20, it extends horizontally from there, and when it approaches the downstream end, it rises toward the upper outer shell 24 and the rear end reaches the vicinity of the upper outer shell 24. The descending portion, the horizontally extending portion, and the ascending portion of the partition plate 22 are referred to as a descending portion 22a, a horizontal portion 22b, and an ascending portion 22c, respectively.

As shown in FIG. 3, the width direction dimension of the partition plate 22 gradually expands toward the downstream at the descending portion 22a and reaches the vicinity of the side wall of the outer shell member 20, and at the horizontal portion 22b, the outer shell member 20 Like the width, it extends downstream with a constant width and narrows at the rising portion 22c. The side edges on both sides of the descending portion 22a are generally spaced downstream, the side edge of the upstream portion is welded to the upper outer shell 24, and the side edge of the downstream portion is with the upper outer shell 24. It is located with a gap 28 between them. The gap in this portion is referred to as a gap 28a. A cross section of the water collecting chamber 18 at the portion where the gap 28a is formed is shown in FIG. 3 (c). The side edge of the horizontal portion 22b of the partition plate extends along the side wall of the outer shell member 20. The side edge of the rising portion 22c is substantially narrowed, the side edge of the upstream portion is located with a gap 28 between it and the upper outer shell 24, and is welded to the upper outer shell 24 at the downstream end. .. The gap 28 formed by the rising portion 22c is referred to as a gap 28b. A cross section of the water collecting chamber 18 at the portion where the gap 28b is formed is shown in FIG. 3 (d).

The upstream edge of the partition plate 22 is arranged at a distance from the upper outer shell 24, from which exhaust gas can flow into the space above the partition plate 22. Further, the downstream edge of the partition plate 22 is also arranged at a distance from the upper outer shell 24, from which the exhaust gas in the space above the partition plate 22 can flow out. Hereinafter, the space above the partition plate 22 will be referred to as an upper flow path 32, and the space below the partition plate 22 will be referred to as a lower flow path 34.

FIG. 4 shows a state in which the water in the exhaust pipe 10 has collected and accumulated in the water collecting chamber 18. The water collected in the water collecting chamber 18 is hereinafter referred to as the accumulated water 36. Since the opening on the upstream side of the upper flow path 32 is small, most of the exhaust gas passing through the water collecting chamber 18 flows through the lower flow path 34. If there is pooled water 36 at the bottom of the water collecting chamber 18, the pooled water 36 narrows the vertical dimension of the lower flow path 34. Therefore, a strong exhaust flow is formed near the water surface of the accumulated water 36, and the accumulated water 36 is sent out toward the downstream by this air flow. Further, the exhaust flow is a pulsatile flow, which makes the surface of the accumulated water 36 more rippling, the splash rises, and the splash is blown up by the exhaust flow and rises the inclination of the exhaust pipe 10 on the downstream side to raise the water collecting chamber. It is discharged from 18.

When the water level of the pooled water 36 is low, most of the exhaust gas descends along the inclination of the descending portion 22a of the partition plate as shown by the arrow F, and is sent to the lower flow path 34 as it is. When the water level of the accumulated water 36 rises, the lower flow path 34 narrows and it becomes difficult for the exhaust to pass through. Therefore, the exhaust is a gap 28 formed between the edge of the partition plate 22 and the outer shell member 20 as shown by the arrow G. In particular, it flows from the lower flow path 34 to the upper flow path 32 through the gap 28a. Further, in the rear part of the upper flow path 32, as shown by an arrow H, the flow flows from the upper flow path 32 to the lower flow path 34 through the gap 28, particularly the gap 28b. As a result, the cross-sectional area of the exhaust flow path is increased, and the increase in back pressure is suppressed.

10 Exhaust pipe, 12 Catalytic converter, 14 Sub muffler, 16 Main muffler, 18 Water collection chamber, 20 Outer shell member, 22 Partition plate, 24 Upper outer shell, 26 Lower outer shell, 28 Gap, 32 Upper flow path, 34 Lower Side flow path, 36 pooled water.

Claims (1)

It is a water collection chamber that is installed in the exhaust pipe that sends the exhaust of the internal combustion engine mounted on the vehicle and collects the condensed water in the exhaust pipe.
An outer shell member that forms a pipeline through which exhaust gas flows,
A partition plate arranged inside the outer shell member and partitioning the inside of the outer shell member up and down,
Have,
The partition plate is joined to the outer shell member at the left and right side edges of the upstream end and the downstream end, and is left and right at least a part of the intermediate portion between the upstream end and the downstream end. It edges and is provided with a gap between the outer shell member,
Further, the partition plate has a descending portion that gradually descends toward the upstream side as it goes downstream, and a horizontal portion that extends horizontally near the center of the height of the outer shell member on the downstream side following the descending portion. Also has an ascending portion that rises further downstream as it goes downstream, following the horizontal portion.
Further, the gap is provided between a part of the descending portion and the outer shell member, and between a part of the rising portion and the outer shell member.
Water collection chamber for exhaust pipes for internal combustion engines.

Images