JPS6233951Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an exhaust system of an internal combustion engine such as a motorcycle, and particularly to a collection chamber that collects a plurality of exhaust pipes of a multi-cylinder internal combustion engine and leads to a common muffler sound.

The present applicant previously proposed in Utility Model Application No. 1490/1983 to cast this type of collective chamber from a light alloy such as aluminum. In this case, the connection part with the exhaust pipe is generally made by cutting a cast hole with high accuracy and inserting the exhaust pipe into the hole, which is cumbersome to process, has poor airtightness, and is cut due to repeated heat and vibration. This caused the parts to wear out, further deteriorating the airtightness and causing chattering noises.

Therefore, it may be possible to fix an exhaust pipe made of the same material to the above-mentioned collecting chamber by means such as welding, but in this case, considerable vibration and stress will be applied to the connection part.
Not only is the strength insufficient, but the workability is also poor.

This project was proposed in view of the above points, and aims to improve the airtightness and durability of the joint between the collecting chamber and the exhaust pipe, and to manufacture this type of exhaust system easily and inexpensively. .

That is, in an exhaust system in which a plurality of exhaust pipes 1 are connected to a silencer 3 via a collection chamber 2, the collection chamber 2 is cast from a relatively lightweight metal with good heat dissipation such as an aluminum alloy, and each exhaust pipe 1 is A connecting sleeve 4 made of iron or the like is integrally cast with the collecting chamber 2.

The illustrated embodiment shows an example in which four exhaust pipes 1 are combined into a single collecting pipe 5 in a collecting chamber 2 and guided to a muffler 3, as shown in FIG.

That is, as shown in FIGS. 2 and 3, one end of the collection chamber 2 is formed into a substantially rectangular shape, and one end of the connection sleeve 4 for the four exhaust pipes 1 is positioned at approximately equal intervals on the same circumference. The other end of the collecting chamber 2 is cast into one end of a connecting sleeve 6 for the collecting pipe 5. Numerals 4a and 6a are protrusions for preventing the connection sleeves 4 and 6 from coming off and rotating, and are formed, for example, by bending the casting side ends of the connection sleeves 4 and 6 outward at several points in the circumferential direction.

Inside the collecting chamber 2 is a passage 7 that communicates from the connecting sleeve 4 of each exhaust pipe 1 to the connecting sleeve 6 of the collecting pipe 5.
It is formed to have a continuous smooth surface to prevent a drop in output due to ventilation resistance. In addition, each of the exhaust pipes 1 and the collecting pipes 5 are fitted into the respective receiving tubes 4 and 6 to form bands 8 and 6.
Tighten and secure with 9 etc. However, the silencer 3 may be directly connected to the receiving tube 6.

In the figure, reference numeral 10 denotes a bracket for attaching the collective chamber 2 to the vehicle body, etc. In the case shown, it is made of two approximately L-shaped iron plates fixed back to back and cast integrally with the collective chamber 2.

In this case, as described above, the collecting chamber 2 is cast from metal, and the connection receivers 4 for the plurality of exhaust pipes 1 are integrally cast with the collecting chamber 2, so this type of exhaust system can be manufactured extremely easily and inexpensively. In addition, there is no need to perform finishing work on a casting hole for fitting the exhaust pipe 1 into the collecting chamber 2, and the exhaust pipe 1 can be connected extremely easily and with good airtightness. In addition, by connecting the exhaust pipe 1 to the collection chamber 2 via the receiving tube 4, stress caused by vibration etc. is dispersed, and stress does not concentrate at the connection between the exhaust pipe 1 and the collection chamber 2 as in the conventional case. Because there is no such thing, there are effects such as good durability.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the exhaust system of the combustion engine in this guide, Figure 2
The figure is an enlarged longitudinal sectional view of the gathering chamber, and Figure 3 is the second
It is a figure-line sectional view. 1 is an exhaust pipe, 2 is a collection chamber, 3 is a silencer,
4 and 6 are connecting pipes, and 5 is a collecting pipe.

Claims (1)

[Scope of utility model registration request] An exhaust system for an internal combustion engine in which a plurality of exhaust pipes are connected to a muffler via a collecting chamber, the collecting chamber being cast from metal, and a connecting sleeve for each exhaust pipe being integrally cast with the collecting chamber. system.