JPH0436246B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a muffler for an internal combustion engine.

(Prior art) Conventional mufflers installed in exhaust pipes are divided into several types of muffling methods, but they are devices for muffling noise.
Since it lowers the exhaust efficiency, it is not preferable from the viewpoint of the efficiency of the internal combustion engine.

(Technical Problem) An object of the present invention is to provide a muffler with a structure capable of accelerating the exhaust gas flow to create a vacuum state and thereby sucking the air flow.

(Technical Means) In order to achieve the above object, the present invention comprises a cylindrical main body 5 which is connected to an end of an exhaust pipe T of an internal combustion engine and has an exhaust passage 1 in the center for discharging exhaust gas;
It consists of a muffler 7 connected to the rear end of the main body 5 in order to muffle the exhaust gas discharged from the exhaust flow path 1 and then release it into the atmosphere. Throttling means 3, 21 for reducing the cross-sectional area are provided in the exhaust flow path 1, and a stirring chamber 4 is set in the exhaust flow path 1 immediately after the throttling means 3, 21. One end of the introduction pipe 2 for sucking outside air into the stirring chamber 4 by the low pressure generated by the acceleration of the exhaust gas flow is connected to the main body 5, and the other end of the introduction pipe 2 is connected directly or through a heat exchanger. It is configured so that the exhaust gas and the outside air are mixed in the stirring chamber 4 through indirect communication with the outside air.

(Embodiment) The illustrated embodiment is for a two-wheeled motor vehicle, and is attached to an exhaust pipe T from a gasoline engine E.

The device shown in FIG. 1 is constructed by installing a conical cylinder 3 with a closed front end and an open rear end in the center of an exhaust flow path 1 of a muffler M as a means to narrow down the cross-sectional area of the flow path. A narrow acceleration flow path S is provided between the inner wall of the cylinder 1 and the outer wall of the cylinder 3, that is, the cooling cylinder. The cylinder body 3 communicates with the outside through the introduction pipe 2, and the exhaust port 3' of the cylinder body 3 opens at the center of the exhaust gas flow, so that the gas flowing into the cylinder body 3 from the introduction pipe 2 flows downstream of the cylinder body. The stirring chamber 4 is designed to stir the high-temperature gas flow from the inside.

5 is the main body of the device, 6 is a connection port with the exhaust pipe T connected to the front end of the device, and the exhaust flow path 1 in the center of the main body
It is familiar to The main body 5 has a muffler 7 connected to the rear end, which is connected to an inner cylinder 8 forming the main exhaust flow path 1.
, a middle cylinder 9 which surrounds the inner cylinder 8 and forms a side passage 11 therebetween to shut off the inside and outside, and an outer cylinder 10 for heat dissipation which surrounds the middle cylinder 9. A large number of gas passages 12 are opened in the inner cylinder 8, and the gas passages 12 communicate with the side passage 11 and the exhaust flow passage 1.
A heat radiation port 13 is opened in the outer cylinder 10.

Reference numerals 14 and 15 denote front and rear cylinder bodies of the muffler 7, in which an inner cylinder 8, a middle cylinder 9, and an outer cylinder 10 are assembled and connected to the main body 5. Reference numeral 16 indicates an exhaust port of a side passage opened in the rear cylinder body 15, and 17 indicates a porous exhaust port at the rear end of the exhaust flow path, which has a hole member 18. Further, 19 indicates a member to which the cylindrical body 3 is fixed at the main body joint. Introductory pipe 2 has
The outside air is introduced directly from the outside air intake system 20 or indirectly through an oil cooler or the like.

According to the above configuration, a high-temperature gas flow flows into the main body 5 from the exhaust pipe T (solid arrow), is accelerated by flowing through the accelerating passage S around the cylinder 3, and is accelerated inside the cylinder 3 which is the throttling means. exchange heat with the low-temperature air stream.
The exhaust gas flow is accelerated in the accelerating flow path S, and acts through the exhaust port 3' of the cylinder 3 to suck the low-temperature air flow inside the cylinder toward the mixing chamber 4. For this reason,
An airflow is generated from inside the inlet pipe 2 toward the outlet 3'. Note that the airflow is from the gas passage 12 to the side passage 11.
The sound is muffled by expanding and flowing out into the air, and by exiting from the porous exhaust hole 17.

FIG. 5 shows a mixing chamber 2 in which a high-temperature gas flow and a cooling air flow are formed on the upstream side of a small-diameter exhaust flow path 1 near a connection port 6 of a main body 5 through a constriction section 21 that is a means for restricting the cross-sectional area of the flow path.
2, from the constriction part 21 to the inlet 1' of the exhaust flow path 1.
In this example, the acceleration flow path S is the introduction pipe 2.
The discharge port 2' is open to the acceleration flow path S. In this example, the inner cylinder 8 is provided in two layers, and the side passage 11 is also provided in two layers to reduce the resistance to passage of airflow, and to perform a noise reduction effect in two stages at the same location.

In the example of FIG. 5, the other configurations may be the same as those of FIG. 1 except that the cylinder 3 itself is not required, so the reference numerals will be used and descriptions of the respective parts will be omitted.

(Operation of the Invention) Since the present invention is constructed as described above, the exhaust gas flow discharged from the engine is accelerated in the throttle means 3 and 21 provided in the exhaust flow path 1, and a vacuum state is created. , produces the effect of suctioning the gas in the line leading to the inlet located near it. In other words, while conventional mufflers have no effective function other than silencing, the present invention has the effect of constantly sucking outside air through the inlet while the internal combustion engine is operating. This gives rise to the possibility that the suction action can be used in various ways.

(Effects of the Invention) Therefore, according to the present invention, external air is introduced into the mixing chamber 4 from the introduction pipe 2, mixed with the exhaust gas, and then released into the atmosphere, thereby making it possible to prevent thermal pollution. In addition, by connecting the introduction pipe 2 to a radiator, oil cooler, intercooler, or other heat exchanger and sucking the air acting on them, the heat exchange action in the equipment is promoted. In particular, the advantage of the present invention is that even in the heat exchanger of equipment used stationary such as construction equipment, a certain cooling effect can be obtained due to the above-mentioned constant suction action, and for internal combustion engines, the exhaust pressure can be kept constant and the exhaust efficiency can be optimized. In addition to contributing to the
It has remarkable effects such as reducing CO ₂ and eliminating the need for the electric fan that was previously required.

[Brief explanation of drawings]

The drawings show an exhaust gas cooling device according to the present invention, and FIG. 1 is a longitudinal sectional view of the first embodiment, FIG. 2 is a cross-sectional view in the direction of the arrow in FIG. 1, and FIG. 3 is a rear view. 4
The figure is a side view showing an example of mounting on a motorcycle.
The figure is a side view of the second embodiment. S...Acceleration flow path, T...Exhaust pipe, 1...Exhaust flow path, 2
...Introduction pipe, 3, 21... Throttling means, 4... Discharge port, 11... Side passage, 12... Gas passage.

Claims (1)

[Claims] 1 A cylindrical main body 5 connected to an end of an exhaust pipe T of an internal combustion engine and having an exhaust flow path 1 at the center for discharging exhaust gas, and a cylindrical body 5 that is connected to an end of an exhaust pipe T of an internal combustion engine and has an exhaust flow path 1 in the center for discharging exhaust gas. The main body 5 will be released into the atmosphere later.
Throttle means 3 and 21 are provided in the exhaust flow path 1 to reduce the cross-sectional area of the exhaust flow path 1 in order to accelerate the flow rate of exhaust gas. A stirring chamber 4 is set in the exhaust flow path 1 immediately after the means 3, 21, and the agitation means 3,
One end of the introduction pipe 2 for sucking outside air into the stirring chamber 4 by the low pressure generated by the acceleration of the exhaust gas flow at step 21 is connected to the main body 5, and the other end of the introduction pipe 2 is connected directly or to a heat exchanger. A muffler characterized in that it is configured to indirectly communicate with outside air through a muffler.