JPH07259550A - Exhaust system structure in automobile - Google Patents

Abstract

PURPOSE:To prevent such a possibility that condensed water might stay in a muffling chamber due to the cooling of exhaust gas and clog yjr gas inflow port of an outlet pipe from occurring, in a car exhaust system. CONSTITUTION:Gas to be exhausted out of an engine through an exhaust pipe produces condensed water if it is cooled, and this water stays in a muffling chamber 4, clogging a passage of the exhaust gas in an outlet pipe 42. In order to cope with such a fact, a backflow hole A of this condensed water is installed in and around a gas inflow port of the outlet pipe 42 of an inlet pipe 41, whereby the stayed condensed water W turns back to a center pipe, so that it will in no case clog the passage of gas flowing into the outlet pipe 42, and thus any inconvenience due to condensed water freezing in the winter is preventable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine, and more particularly to the structure of an exhaust system for releasing exhaust gas of an automobile into the atmosphere.

[0002]

2. Description of the Prior Art Exhaust gas from an automobile engine is generally discharged from a front engine toward a rear through an exhaust pipe, and as shown in FIG. In the process of passing through the catalyst converter 2, the center pipe 3, the muffling chamber 4, the tail pipe 5, etc., the exhaust gas is cooled and condensed water is produced. This condensed water flows in the exhaust pipe, and if the amount increases, it hinders the exhaust gas emission, which in turn increases the exhaust pressure, which lowers the output of the internal combustion engine and reduces the effect of the muffler. After stopping, there was a problem such as freezing of condensed water. Accumulation of condensed water increases toward the end of the exhaust system, for example, near the silencing chamber. In the muffler chamber 4, for example, as shown in FIG. 5, an inlet pipe 41 and an outlet pipe 42 are baffle pre-loaded.
Although it is connected via a port 43, the muffling room 4 is the center.
When the condensed water stays inside the muffler chamber and freezes in the winter when the pipe 3 is tilted with respect to the pipe 3 and the inlet pipe 41 is installed in the lower portion, the passage to the outlet pipe 42 is blocked as shown in FIG. It may cause a failure at the time of starting.

For this reason, conventionally, in a dual type exhaust silencer, the opening portion in the silencer of a long tail pipe is
It is configured so that it is located higher than the opening of the silencer of the short tail pipe, and the condensed water flows from the opening provided in the long tail pipe to the short tail pipe, and then flows into the long tail pipe. Reduce the amount of condensed water
-6808), instead of providing a drainage pipe,
There is one in which a main exhaust pipe is provided in the lower part of the muffler and a sub exhaust pipe is provided in the upper part, and the diameter of the main exhaust pipe is set to be larger than the diameter of the sub exhaust pipe (actual fair 2-18278).
Issue).

[0004]

The treatment of the condensed water of the exhaust gas shown in these prior arts is to solve structurally, but the structure is rather complicated. The present invention, with a simple structure, prevents inconveniences caused by freezing of condensed water in the exhaust system in winter.

[0005]

Therefore, according to the present invention, in the exhaust system of an automobile in which the muffler chamber is inclined, the portion of the inlet pipe located near the exhaust gas inlet of the outlet pipe in the muffler chamber is provided. The exhaust system structure of the automobile is provided with a backflow hole for condensed water.

[0006]

With this structure, even if the condensed water stays in the muffling chamber, an appropriate amount of condensed water flows in the direction of the center pipe from the backflow hole provided in the inlet pipe, which occurs especially after the engine is stopped in winter. By freezing condensed water,
The outlet pipe will not be blocked.

[0007]

EXAMPLE An example of the present invention will be described with reference to FIG.
It should be noted that the same parts as those of the related art will be described using the same reference numerals. Exhaust gas generated by the rotation of the engine is discharged through the exhaust pipe toward the outlet, and condensed water W generated in the process is discharged from the center pipe 3 to the inlet pipe 4.
Stay at 1. In the present invention, the backflow hole A is intentionally provided at a suitable position of the inlet pipe 41 near the opening of the outlet pipe 42, and even if the condensed water W collects, it flows back toward the center pipe 3 through the opening A. As a result, even if the silencer 4 is installed so as to be tilted with respect to the center pipe 3 and the condensed water W may freeze, the silencer 4 does not block the opening of the outlet pipe 42 and an obstacle occurs when the engine is started. It never happens.

The frozen portion is also thawed by the temperature rise caused by the engine start, gradually sent to the tail pipe, and discharged to the outside. Further, the condensed water flowing back to the center pipe 3 is accumulated in a relatively long portion even if it is frozen, and the flow of the exhaust gas is released when the temperature rises due to the start of the engine and is gradually discharged to the rear part. It

If the position of the backflow hole is improper, the center of the muffler chamber 4 can be formed even if there is little condensed water W as shown in FIG.
Since the condensed water W accumulates in the entire inside of the pipe 3,
When freezing, the center pipe 3 may burst. Therefore, a single or a plurality of backflow holes A are provided as needed, but their positions are appropriately provided in the radial direction of the inlet pipe or in the spiral direction with respect to the axis of the inlet pipe as shown in FIGS. 2 and 3. To be The amount of the condensed water flowing back is adjusted by appropriately rotating the inlet pipe 41 when attaching the inlet pipe 41 to the muffling chamber. The backflow hole may be provided not only in the inlet pipe, but also in the outlet pipe depending on how the exhaust system is provided, the muffler chamber, and the positional relationship between the inlet pipe and the outlet pipe. In that case, the condensed water is made to flow toward the tail pipe.

[0010]

EFFECTS OF THE INVENTION Since the present invention is constructed as described above, it is not necessary to specially provide other parts, but only by intentionally providing a hole for backflowing condensed water, the conventional outlet pipe It does not block the passage of exhaust gas and can prevent obstacles such as engine starting failure. or,
The amount of condensed water that flows backward can be adjusted simply by changing the rotation direction when installing the inlet pipe.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a muffling chamber having an inlet pipe provided with a backflow hole according to the present invention.

FIG. 2 is a view in which a plurality of backflow holes are provided in the inlet pipe.

FIG. 3 is a sectional view taken along the backflow hole in FIG.

FIG. 4 is a diagram showing a case where the position of the backflow hole is incorrect.

FIG. 5 is a diagram showing an entire muffler system.

FIG. 6 is a diagram showing a conventional silencing chamber.

FIG. 7 is a diagram in which condensed water is retained in a conventional silencing chamber.

[Explanation of symbols]

 3 Center pipe 4 Silencer chamber 41 Inlet pipe 42 Outlet pipe A Backflow hole W Condensed water

Claims (4)

[Claims] 1. In an exhaust system of a vehicle in which a muffler chamber is inclined, a vehicle in which a condensate backflow hole is provided in a portion of an inlet pipe located near an exhaust gas inlet of an outlet pipe in the muffler chamber. Exhaust system structure. 2. The structure of an exhaust system for an automobile according to claim 1, wherein the number of backflow holes of the condensed water is one or more. 3. The structure of the exhaust system of an automobile according to claim 1, wherein a hole through which condensed water flows is provided in the outlet pipe. 4. The structure of an exhaust system for an automobile according to claim 1, wherein the backflow hole for the condensed water is provided in a radial direction of the inlet pipe or in a spiral direction with respect to an axis of the inlet pipe.