JPH09310616A - Structure for tail pipe of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent water drops from falling, for instance, on a vehicle body by providing a tail pipe structure which has measure for not discharging of water drops. SOLUTION: Steam in exhaust introduced from a base end pipe 3 to an intermediate pipe 4 is condensed in the intermediate pipe 4 to form water drops. In this case, the diameter of the intermediate pipe 4 is larger than that of the base end pipe 3 for abruptly decelerating exhaust velocity introduced into the intermediate pipe 4. The water drops are hardly removed to outside by the exhaust flow. A leading end pipe 5 penetrates a peripheral surface of the intermediate pipe 4, so that the water drops to be discharged outside along an inner periphery of the intermediate pipe 4 is interrupted by a projection from the inner peripheral surface of the intermediate pipe 4. It is thus possible to prevent condensed water from being discharged outside from the leading end pipe 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine tail pipe, and more particularly to a technique for preventing discharge of water droplets from the tail pipe caused by condensation of water vapor in exhaust gas.

[0002]

2. Description of the Related Art A large amount of water vapor is contained in exhaust gas emitted from an engine mounted on a vehicle or the like. Therefore, when the temperature is low such as in winter, the water vapor in the exhaust gas is condensed in the exhaust pipe and is discharged as water droplets from the tail pipe which is the final tail pipe (exhaust pipe from the muffler to the last end) of the exhaust pipe.

In a normal vehicle, there is no problem even if water drops are discharged from the tail pipe.

[0004]

However, in a special vehicle such as a construction machine, a tail pipe may be installed on the vehicle body. In the case of a conventional tail pipe, water droplets discharged from the tail pipe may be on the vehicle body. And the vehicle body may be soiled. The present invention has been made in view of the above, and it is an object of the present invention to prevent, for example, water drops from falling onto a vehicle body by adopting a tail pipe structure that takes measures to prevent water drops from being discharged.

[0005]

Therefore, the invention according to claim 1 is a tail pipe constituting an exhaust pipe portion from an muffler to a rear end of an engine, the tail pipe body being connected to the muffler. A small-diameter base end pipe portion, a large-diameter intermediate pipe portion having a closed distal end portion connected to the pipe portion, and a distal end pipe portion penetratingly connected to the distal end peripheral portion of the pipe portion. It was a tail pipe of an engine that was configured to include.

According to a second aspect of the present invention, there is provided a tail pipe which constitutes an exhaust pipe portion from the muffler of the engine to the rear end thereof, and the plate surface is provided inside the tail pipe main body in the vicinity of the connection portion with the muffler. A water vapor condensation plate that is substantially orthogonal to the exhaust flow direction of the pipe body is provided, and a tail pipe body is provided with a water drop discharge port that communicates the inside and outside of the water vapor condensation plate on the upstream side of the water vapor condensation plate.

According to the third aspect of the invention, the water droplet discharge port is formed by a hole formed in the peripheral wall of the tail pipe body. In the invention according to claim 4, an outer cylinder opened to the upstream side is attached to the outer peripheral portion of the tail pipe body so as to surround the hole forming portion of the peripheral wall of the main body.

The invention according to claim 5 is a tail pipe which constitutes an exhaust pipe portion from a muffler to a rear end of an engine, wherein the tail pipe body has a small-diameter base end pipe portion connected to the muffler. The tail pipe main body is configured to include a large-diameter intermediate pipe portion connected to the pipe portion and having a closed tip end portion, and a tip pipe portion penetratingly connected to a tip peripheral portion of the pipe portion. Inside the vicinity of the connection portion with the muffler, a steam condensation plate whose plate surface is substantially orthogonal to the exhaust flow direction of the tail pipe main body is disposed, and the inside and outside of the main body are connected to the tail pipe main body on the upstream side of the steam condensation plate. It was used as an engine tail pipe with a water droplet discharge port communicating with it.

According to a sixth aspect of the present invention, the upstream end of the intermediate pipe portion is opened as the water droplet discharge port, and the base end pipe portion is provided in the opening portion with a gap between the inner peripheral surface of the opening portion. And the inner peripheral surface of the open portion and the outer peripheral surface of the base end pipe portion are connected via a supporting member.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of the present invention. In this drawing, a tail pipe 1 constituting an exhaust pipe portion from a muffler (not shown) to the rear end of the engine is shown.
The main body 2 of the above is installed by being raised from the muffler.

The tail pipe body 2 has a small-diameter base end pipe portion 3 connected to a muffler, a large-diameter intermediate pipe portion 4 connected to the pipe portion 3 and having a closed distal end portion, and the pipe portion. 4 and a distal end pipe portion 5 penetratingly connected to the peripheral portion of the distal end of the pipe 4. Here, the base end pipe portion 3 is composed of an elbow pipe having a connection flange portion 3A for connecting with a muffler at one end portion.

The intermediate pipe portion 4 is composed of a cylindrical straight pipe, and both the upstream end portion and the downstream end portion are closed. Then, the connection port 4 formed on the upstream end wall of the intermediate pipe portion 4
The base end tube portion 3 is penetratingly connected to A. The tip tube portion 5 is formed of a cylindrical straight tube, and is penetratingly connected to a connection port 4B formed in the peripheral wall of the tip portion of the intermediate tube portion 4.

In this case, the tip pipe portion 5 is connected to the central axis of the intermediate pipe portion 4 while being inclined upward at a predetermined angle. In such a configuration, the water vapor in the exhaust gas introduced from the proximal end pipe part 3 into the intermediate end pipe part 4 is condensed in the intermediate end pipe part 4 to form water droplets. Since it has a larger diameter than the above, and the exhaust flow velocity introduced into the intermediate pipe portion 4 is rapidly reduced, it becomes difficult for water droplets to be carried away from the tip pipe portion 5 to the outside by the exhaust flow, and the water droplets Pipe part 5
It is possible to suppress the discharge from the outside.

Further, since the tip pipe portion 5 penetrates the peripheral wall of the intermediate pipe portion 4, water drops which are to be discharged to the outside along the inner peripheral surface of the intermediate pipe portion 4 have an intermediate pipe portion. 4 is prevented by the projecting portion from the inner peripheral surface, which also makes it possible to suppress the dew condensation water from being discharged from the tip pipe portion 5 to the outside. Next, another embodiment of the present invention will be described with reference to FIG.

In this figure, the plate surface is tailed inside the vicinity of the connection portion of the tail pipe main body 2 with the muffler, that is, near the connection portion of the intermediate pipe portion 4 of the tail pipe main body 2 with the proximal end pipe portion 5. A circular water vapor condensation plate 6 that is substantially orthogonal to the exhaust flow direction of the pipe body 2 is disposed and fixed. The water vapor condensation plate 6
The tail pipe body 2 on the upstream side is formed with a water droplet discharge port that communicates the inside and outside of the body 2. In this embodiment,
The upstream end of the intermediate pipe portion 4 is opened, and this opening is used as the water droplet discharge port 7.

In this case, the proximal pipe portion 3 is inserted into the opening at the upstream end of the intermediate pipe portion 4, and the inner peripheral surface of the intermediate pipe portion 4 and the outer peripheral surface of the proximal pipe portion 3 are plural. Are connected via the plate-shaped support member 8. In such a configuration, the exhaust gas guided from the proximal end pipe portion 3 into the intermediate pipe portion 4 collides with the upstream surface of the water vapor condensation plate 6, whereby the upstream surface of the water vapor condensation plate 6 is exhausted. Condensation of water vapor.

When the amount of water droplets condensed on the water vapor condensation plate 6 is small, the water droplets are made to flow to the inner peripheral surface of the intermediate pipe portion 4 by exhaust,
It rises along the inner peripheral surface of the intermediate pipe portion 4, and during this time, it is vaporized again by the heat of the exhaust gas and discharged. When there are many water droplets condensed on the water vapor condensation plate 6, the water droplets drop along the inner peripheral surface of the intermediate pipe portion 4 on the upstream side of the water vapor condensation plate 6, and the open portion of the intermediate pipe portion 4, that is, the water droplets. It is discharged from the discharge port 7 to the outside.

Therefore, according to this structure, it is possible to prevent the condensed water from being discharged from the tip tube portion 5 to the outside. FIG.
As shown in, the water drop discharge port 9 may be composed of a plurality of slits as holes formed in the peripheral wall of the tail pipe body 2. Further, it is not limited to the slit, and may be a simple hole or a small hole continuously formed in the circumferential direction.

Also in this case, the base end pipe portion 3 is penetratingly connected to the connection port 4A formed on the upstream end wall of the intermediate pipe portion 4. Further, an outer cylinder 10 opened on the upstream side may be attached to the outer peripheral portion of the tail pipe body 2 so as to surround the water droplet discharge port 9 forming portion. In this way, the outer cylinder 1
By setting 0, the water droplets discharged from the water droplet discharge port 9 are guided downward by the outer cylinder 10 and smoothly dropped without being scattered around.

According to the above-described embodiment, in a special vehicle such as a construction machine, even if a tail pipe is installed on the vehicle body, there is no risk of water droplets falling on the vehicle body and polluting the vehicle body. . As shown in FIG. 2, the tail pipe main body 2 includes a small-diameter base pipe portion 3 and a large-diameter intermediate pipe portion 4.
Alternatively, the configuration including the tip tube portion 5 and the configuration including the water vapor condensation plate 6 and the water droplet discharge port 9 may be provided in parallel.

[0021]

As described above, according to the first aspect of the invention, it becomes difficult for water droplets to be carried away from the tip tube portion to the outside by the exhaust flow, and the water droplets are prevented from being discharged from the tip tube portion to the outside. At the same time, water droplets that are about to be discharged to the outside along the inner peripheral surface of the intermediate pipe portion are blocked by the protruding portion of the tip pipe portion from the inner peripheral surface of the intermediate pipe portion. Can be suppressed from being discharged.

According to the second aspect of the present invention, water vapor is condensed on the water vapor condensation plate, and the water vapor is dropped along the inner peripheral surface of the intermediate pipe portion on the upstream side of the water vapor condensation plate to discharge water droplets from the intermediate pipe portion. Since the water can be dropped and discharged to the outside from the outlet, the condensed water can be suppressed from being discharged to the outside from the tip tube portion. According to the third aspect of the invention, the water droplets formed on the water vapor condensation plate by the condensation of the water vapor can be discharged to the outside from the water droplet discharge port formed of the hole formed on the peripheral wall of the main body of the tail pipe.

According to the invention of claim 4, the water droplets discharged from the water droplet discharge port are guided by the outer cylinder and smoothly flow without being scattered around. According to the invention of claim 5, it becomes difficult for water droplets to be carried away from the tip tube portion to the outside by the exhaust flow, and it is possible to suppress the water droplets from being discharged from the tip tube portion to the outside, and along the inner peripheral surface of the intermediate tube portion. The water droplets that are to be discharged to the outside are blocked by the protruding portion from the inner peripheral surface of the intermediate tube portion of the tip tube portion, which also prevents the condensed water from being discharged from the tip tube portion to the outside. Since the water vapor is condensed on the dew condensation plate and dropped along the inner peripheral surface of the intermediate pipe portion on the upstream side of the water vapor dew condensation plate, the water droplet discharge port of the intermediate pipe portion can be dropped and discharged to the outside.
Condensation water can be suppressed from being discharged from the tip tube portion to the outside.

According to the sixth aspect of the present invention, the water droplets formed on the water vapor condensation plate by the dew condensation of the water vapor can be discharged to the outside from the water droplet discharge port formed of the opening at the upstream end of the intermediate pipe section.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the present invention.

FIG. 3 is a sectional view showing still another embodiment of the present invention.

[Explanation of symbols]

 1 Tail pipe 2 Tail pipe body 3 Base end pipe part 4 Intermediate pipe part 5 Tip pipe part 6 Water vapor condensation plate 7 Water droplet discharge port 8 Plate-shaped support member 9 Water droplet discharge port 10 Outer cylinder

Claims (6)

[Claims] 1. A tail pipe constituting an exhaust pipe portion from a muffler to a rear end of an engine, the tail pipe main body having a small-diameter base end pipe portion connected to the muffler and being connected to the pipe portion. A tail pipe for an engine, comprising: a large-diameter intermediate pipe portion having a closed front end portion; and a front end pipe portion penetratingly connected to a front end peripheral portion of the pipe portion. 2. A tail pipe constituting an exhaust pipe portion from a muffler to a rear end of an engine, wherein a plate surface is provided inside a tail pipe main body in a vicinity of a connecting portion with the muffler, and an exhaust flow direction of the tail pipe main body. A tail pipe for an engine, characterized in that a water vapor condensation plate that is substantially orthogonal to the water vapor condensation plate is disposed, and a water drop discharge port that communicates the inside and outside of the main body is formed in the tail pipe body on the upstream side of the water vapor condensation plate. 3. The tail pipe for an engine according to claim 2, wherein the water droplet discharge port is a hole formed in the peripheral wall of the tail pipe body. 4. The tail pipe for an engine according to claim 3, wherein an outer cylinder opened upstream is attached to an outer peripheral portion of the tail pipe main body so as to surround the hole forming portion of the peripheral wall of the main body. 5. A tail pipe that constitutes an exhaust pipe portion from a muffler to a rear end of an engine, the tail pipe body having a small-diameter base end pipe portion connected to the muffler and a pipe portion connected to the pipe portion. And a muffler of the tail pipe body, including a large-diameter intermediate pipe part having a closed tip part and a tip pipe part penetratingly connected to the tip peripheral part of the pipe part. Inside the vicinity, a water vapor condensation plate whose plate surface is substantially orthogonal to the exhaust flow direction of the tail pipe body is arranged, and a water drop discharge port communicating between the inside and outside of the water vapor condensation plate is connected to the tail pipe body on the upstream side. The tail pipe of the engine characterized by being formed. 6. An upstream end of the intermediate pipe section is opened as the water droplet discharge port, and the proximal end pipe section is inserted into the open section with a gap between the open end section and the inner peripheral surface of the open section, The tail pipe for an engine according to claim 5, wherein the inner peripheral surface of the open portion and the outer peripheral surface of the base end pipe portion are connected via a supporting member.