JPS6146175Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a differential user attached to an exhaust gas outlet of an engine exhaust system, and particularly relates to a differential user applied to a dual type exhaust gas outlet.

[Conventional technology]

BACKGROUND OF THE INVENTION As a means for reducing the jet noise and gas temperature of exhaust gas discharged from the tail pipe end of an engine exhaust system, a diffuser has conventionally been installed at the discharge port at the tail pipe end of the exhaust system.

FIGS. 1 and 2 show an example of installing such a differential user, in which a differential user pipe body 2 having a diameter larger than the outside diameter of the pipe is placed on the tail side pipe end 1 of the engine exhaust system, with one end overlapping each other. placed concentrically,
By connecting the pipe body 2 and the exhaust system pipe end 1 with stays 3 arranged radially, the diffuser pipe body 2 was supported on the exhaust system pipe end 1.

According to the differential user of this type of system, when exhaust gas is discharged from the exhaust system pipe end 1 in the direction of arrow A, outside air flows in from the rear opening of the pipe body 2 as shown by arrow B, and thereby the gas from the exhaust system and At the same time, the temperature of the exhaust gas decreases as it mixes with outside air.
By lowering the flow velocity of exhaust gas, the jet noise can be reduced.

However, the exhaust system pipe end 1 and the differential user pipe body 2
Since the stay 3 is used to connect the two, there are many parts to connect the two, and the number of man-hours required to install them increases, resulting in high costs, and there are also problems with vibration durability.

In addition, in exhaust systems where jet noise is a problem, such as in large engines (high displacement), the end of the gas discharge pipe is a dual type, and if the exhaust system is equipped with a tail muffler, etc., safety may be reduced. From this point of view, it becomes necessary to lower the exhaust gas temperature, so a diff user pipe body (not shown) formed from a flat pipe is inserted across the end of the dual exhaust system pipe (not shown). However, a stay having the same structure as the stay 3 described above is used to attach it to each exhaust system pipe end.

However, in this case, the number of man-hours required for attaching the differential user tube and the end of the exhaust system tube using stays increases, resulting in poor workability, and there is still a problem in vibration durability.

Therefore, as a solution for attaching a differential user tube to the pipe end of such a dual type exhaust system, the present inventor devised a differential user shown in FIGS. 3 to 5.

In the figure, 10 is a tail muffler, and a single differential user member 14 is integrally fitted to the tips of a pair of parallel gas discharge pipes 12 and 13 that protrude from one end of the tail muffler 10. .

This differential user member 14 is formed from a flat tube, and its inner width dimension d is
The inner diameter of the portion into which the gas discharge pipes 12 and 13 fit is substantially equal to the outer diameter of the gas discharge pipes 12 and 13.
Further, an outside air inflow opening 15 is formed in a portion surrounded by the gas discharge pipes 12 and 13 and the diffuser member 14. Additionally, numeral 11 in the figure indicates an exhaust gas conduit.

The differential user member 14 is fixed to the gas discharge pipes 12, 13 by forming a slit 16 in the fitting portion of the differential user member 14, as shown in FIG. This is done by press-fitting the side into the gas discharge pipes 12, 13, or after fitting the diffuser member 14 into the gas discharge pipes 12, 13, welding is performed to secure it.

With this differential user and its mounting structure,
This reduces the number of parts, increases work efficiency, and improves vibration durability.

[Problem that the invention attempts to solve]

However, according to such a diffuser, since both sides of the exhaust gas discharged from the gas discharge pipes 12 and 13 are blocked by the inner wall 14a of the member 14 for the diffuser, the discharged exhaust gas flows into the inner wall 14.
As a result, they collided with each other to generate turbulent flow, and although a diff user was provided to prevent noise at the end of the tube, it was not very effective.

[Purpose of invention]

This invention was devised in view of the actual situation,
Can be easily attached to the end of a dual-type exhaust system pipe.
Another object of the present invention is to provide a differential user that ensures smooth expansion of exhaust gas as much as possible, reduces gas jet noise, and improves vibration durability.

[Means for solving problems]

In order to achieve such an object, the present invention provides a single gas discharge tube that is fitted and fixed to the ends of a pair of gas discharge pipes protruding in parallel from the tail portion of the exhaust system by press-fitting each of these discharge pipes at at least two places. is a substantially flat tubular diffuser, and when fitted with a gas discharge pipe, an outside air introduction path is formed between the circumferential wall in the longitudinal direction and the gas discharge pipe, and both walls facing between the gas discharge pipes have at least It is characterized in that the opening end on the exhaust gas outflow side is curved outward or inward with respect to a line connecting the outer circumferences of the gas discharge pipes.

[Effect of invention]

According to the present invention, when exhaust gas is discharged from the gas discharge pipe and flows out into the atmosphere from the tip opening of the diffuser, outside air flows in from the outside air introduction path due to the negative pressure generated inside the diffuser, and the gas is discharged. It mixes with the exhaust gas from the pipe to lower the gas temperature. Furthermore, the gas flow discharged from the gas discharge pipe expands within the diffuser, reducing the gas flow velocity and reducing jet noise. Moreover, since it can be installed by fitting and fixing it to the exhaust pipe, it can be easily installed.

[Example of idea]

Hereinafter, embodiments of the present invention will be described in detail based on FIGS. 6 to 10. Components that are the same as those in the conventional example described above are designated by the same reference numerals.

6 to 8 show a first embodiment of the present invention. In the figures, 20 is a diff user member made of a flat tube, and the inner width dimension d' of this diff user member 20 is It is formed to be larger than the spacing l between both sides of the gas discharge pipes 12 and 13 so that outside air introduction passages 21a and 21b can be formed at both ends when the pipes 12 and 13 are fitted. Furthermore, a differential user member 20 located between the gas discharge pipes 12 and 13
The upper and lower wall portions 20a, 20b of the gas discharge pipe 1
Diff user member 2 from the open end portions 2 and 13
It gradually expands toward the front opening direction of 0,
As a result, the cross-sectional area of the differential user member 20 is formed to gradually increase toward the front opening direction.

To fix the differential user member 20 to the gas discharge pipes 12 and 13, a slit (not shown) is formed in the fitting portion of the differential user member 20, as in FIG.
This is done by press-fitting the slit side into the gas discharge pipes 12, 13, or after the diffuser member 20 is fitted into the gas discharge pipes 12, 13, it is welded and fixed as necessary. In this embodiment, the discharge pipe 1
2 and 13, and are fitted in pressure contact at two places.

Since this embodiment is configured as described above, the exhaust gas is discharged from the gas discharge pipes 12 and 13 as shown by the arrow C, and the distal end opening 20 of the differential user member 20 is
If it leaks into the atmosphere from c, the differential user member 2
Due to the negative pressure generated inside the chamber, outside air flows in from the outside air inflow opening 15 and the outside air introduction paths 21a, 21b as shown by arrow D, mixes with the exhaust gas from the gas discharge pipes 12, 13, and lowers the gas temperature. descend. Also,
The discharged gas flows from the gas discharge pipes 12 and 13 are directed to the upper and lower wall portions 20a and 20b of the differential user member 20.
The differential user member 20
Coupled with the fact that the inner width dimension d' is larger than the distance l between both sides of the gas discharge pipes 12 and 13, gas flow is weakened and jet noise is reduced.

Although the spread of the exhaust gas is restricted at the four pressure points between the gas discharge pipes 12 and 13 and the differential user member 20, it spreads smoothly in other wide areas, although this is not ideal. There is no practical problem. Moreover, this makes it extremely easy to wear.

As described above, according to this embodiment, the jet noise can be reduced, and the number of parts to be installed is reduced, similar to the differential user shown in FIG. 3 above.
The installation workability with the end of the exhaust system pipe has been improved, and the durability against vibration has also been improved.

9 and 10 show a second embodiment of the present invention, and in this embodiment, gas discharge pipes 12, 13
In order to diffuse the exhaust gas discharged from the flat tube to the differential user member 30 to weaken the gas flow velocity and reduce jet noise, the inner width d'' and the radius of both ends of the differential user member 30, which is a flat tube, are The distance L between both sides of the tubes 12 and 13 is made larger than the outer diameter, and the upper and lower walls of the central part of this differential user member 30 are curved inwardly, and the two sides of each side between the curved parts 31a and 31b are made larger than the outer diameter. It is designed so that it can be fitted and fixed to the gas discharge pipes 12 and 13 at multiple locations.

Therefore, according to this embodiment as well, the jet noise can be reduced, and as in the first embodiment, the number of parts to be installed is reduced, so that the workability of installing the exhaust system pipe end is improved. Moreover, vibration durability has also been improved.

[Effect of idea]

As described above, according to the present invention, it is easy to attach to the pipe end of a dual-type exhaust system, and gas jet noise is reduced and vibration durability is improved.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional exhaust system differential user, Figure 2 is a left side view of the exhaust system differential user shown in Figure 1, and Figure 3 is a diagram of the differential user at the stage before the invention was devised. A perspective view showing the state in which it is attached to the end of the dual type gas discharge pipe.
5 is an enlarged sectional view of the main part of the figure, FIG. 5 is a sectional view taken along the line -- in FIG. 4, FIG. 6 is a left side view, FIG. 8 is an enlarged sectional view of the main part of FIG. 6, FIG. 9 is a front view showing the second embodiment of the present invention installed at the end of the gas discharge pipe, and FIG. 10 is a FIG. 9 is a left side view of FIG. 9; 12, 13... Gas discharge pipe, 20, 30... Member for differential user.

Claims (1)

[Claims for Utility Model Registration] (1) A single gas discharge pipe that is fitted and fixed to the ends of a pair of gas discharge pipes protruding in parallel from the tail portion of the exhaust system by being pressed against each of these discharge pipes at at least two places. The diffuser has a substantially flat tubular shape, and when fitted with a gas discharge pipe, an outside air introduction path is formed between the circumferential wall in the longitudinal direction and the gas discharge pipe, and both walls facing between the gas discharge pipes are used for at least exhaust gas. A diffuser for an exhaust system, characterized in that the opening end on the gas outflow side is curved outward or inward with respect to a line connecting the outer periphery of the gas discharge pipe. (2) The diffuser for an exhaust system according to claim 1, wherein both walls facing each other between the gas discharge pipes are gradually expanded in the exhaust gas outflow direction.