JPS636413Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a silencer for an internal combustion engine.

Silencers are essential for noise prevention in internal combustion engines, and because they are exposed to high-temperature exhaust gas, they are generally made of materials such as steel plates with high heat resistance and are quite heavy. There is. On the other hand, in recent years, in order to reduce the weight of vehicles, lightweight materials such as synthetic resin and aluminum are being used as much as possible.In particular, weight reduction in motorcycles is progressing significantly, and as a result, the weight of mufflers has become lighter. It is hoped that this will become a reality.

However, since aluminum, which is a lightweight material, has low heat resistance strength, it is extremely difficult to use it for a silencer, and there are also problems in terms of strength when attaching it to a vehicle body.

The present invention was developed in view of the above points, and its purpose is to reduce the weight of internal combustion engine mufflers and improve the strength of attachment to the vehicle body. A silencer for an internal combustion engine, comprising a cylinder and an internal structure housed in the outer cylinder and connected to an exhaust pipe of the internal combustion engine and formed of a member with high heat resistance and mechanical strength, wherein at least A portion is formed of a lightweight member with low heat resistance strength to thermally isolate it from the internal structure, and
The present invention provides a muffler for an internal combustion engine, which is thermally isolated from the outer cylinder and in which a stay for attachment to a vehicle body is connected and fixed to the internal structure via the outer cylinder.

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 1, a cylinder 3 forming an outer cylinder 2 of a silencer 1 is made of a lightweight material such as aluminum with low heat resistance strength, and annular gaskets having heat resistance and corrosion resistance are installed at both open ends, respectively. Punkin 4,5
The end plates 6 and 7 are fitted through them, and are firmly tightened and fixed by bolts 8 with heat insulating washers. Holes 6a and 7 are formed at predetermined positions in each of these end plates 6 and 7, respectively, with peripheral edges bulging outward in a flange shape.
A is drilled.

The internal structure 10 is formed into a cylindrical shape and has a peripheral surface 10a.
A large number of holes 10b are bored in the opening, and end plates 11 and 12 are fixed to both open ends by welding or the like. Holes 11a and 12a are bored at predetermined positions in these end plates 11 and 12, respectively. This internal structure (hereinafter referred to as a cylinder) 10 has two chambers 15,
These two chambers 15,
16 are communicated with each other through an inner pipe 14 fitted into a hole 13a formed in the partition plate 13.
As shown in FIG. 2, a stay mounting plate 17 having a substantially inverted U-shaped cross section is fixed to the upper surface of the circumferential surface 10a of the cylinder 10, and a screw hole is provided at a predetermined position on the upper surface of the stay mounting plate 17. 17a is formed. The cylindrical body 10, end plates 11 and 12, partition plate 13, pipe 14, and stay mounting plate 17 are made of a material having high heat resistance and mechanical strength, such as an iron plate. The upper surface of the stay mounting plate 17 is in contact with the inner circumferential surface of the cylindrical body 3 via a gasket packing 18 having heat and corrosion resistance. A muffler stay 20 is disposed on the outer peripheral surface of the cylinder 3 at a position facing the stay mounting plate 17 via a heat-resistant and corrosion-resistant gasket packing 19.
0 is firmly tightened and fixed to the stay mounting plate 17 via the heat insulating gasket packing 19, the cylindrical body 3 and the heat insulating gasket packing 18 by a bolt 21 with a heat insulating washer screwed into the screw hole 17a of the stay mounting plate 17. There is.

One end of the stay 22 for supporting the internal structure is connected to the cylindrical body 1
The other end is in contact with the inner circumferential surface of the cylinder 3 via a heat-resistant and corrosion-resistant gasket packing 23, and the bolt 24 with a heat-insulating washer is attached to the It is firmly tightened and fixed to the cylindrical body 10. That is, the cylindrical body 10 is firmly supported and fixed to the cylindrical body 3 by the stay mounting plate 17 and the stay 22. In this installation state,
The holes 6a, 7a in the end plates 6, 7 of the outer cylinder 2 and the holes 11a, 12a in the end plates 11, 12 of the cylinder body 10 are opposite to each other, and each hole 6a, 11a in the end plates 6, 11 has a hole. An exhaust pipe 30 of an engine (not shown) is fitted into each hole 7a, 12a of the end plates 7, 12.
1 is inserted. A large number of small holes 30a and 31a are bored in the peripheral wall between the exhaust pipe 30 and the end plates 6, 11 and 7, 12 of the tail pipe 31, respectively. In addition, a member 25 having heat insulation and sound absorption effects is provided in the space formed between the outer cylinder 2 and the cylinder body 10.
is filled. The silencer 1 having such a configuration is connected to the frame pipe 33 of the vehicle body via the muffler stay 20.
The stay 33a is firmly fixed to the stay 33a by bolts 34 and nuts 35.

By the way, since the cylindrical body 10 is made of a material with strong mechanical strength such as a steel plate as described above, the muffler stay 20 can be firmly fixed to the cylindrical body 10, and therefore the cylinder 10 and the exhaust gas Since the muffler 1 can be attached to the vehicle body through the pipe 30, the load of the muffler 1 is not applied to the outer cylinder 2.

In addition, when aluminum and iron come into direct contact, aluminum will be electrolytically corroded, but the cylindrical body 3 made of aluminum and the stay mounting plate 17 made of iron,
By interposing heat-resistant and corrosion-resistant gasket packings 18 and 19 between the cylindrical body 3 and the stay 20,
Galvanic corrosion is prevented. Furthermore, the strength of aluminum is extremely reduced when welded, but since the cylindrical body 3 has no welded parts, there is no reduction in strength.

In this configuration, the exhaust gas discharged from the exhaust pipe 31 enters the chamber 15 of the cylinder body 10 and the inner pipe 1.
4. While being discharged from the tailpipe 31 through the chamber 16, its temperature is lowered, and most of the explosion noise is emitted from the small holes 30a, 10b, 31a of the exhaust pipe 30, cylinder 10, and tailpipe 31 to the outer cylinder 3. The sound is radiated inward and is absorbed by the heat insulating sound absorbing member 25. Furthermore, although the exhaust pipe 30, end plates 6, 7, cylinder body 10, stay mounting plate 17, and tail pipe 31 become high in temperature due to exhaust gas, the conduction to the heat cylinder body 3 is prevented by the heat insulation and sound absorption member 25, heat insulation and Corrosion gasket packing 4,
5, 18, and 19 to prevent the temperature of the cylinder 3 from rising.

As explained above, according to the present invention, the outer cylinder and
In the muffler for an internal combustion engine, the internal structure is housed in the outer cylinder, connected to the exhaust pipe, and is made of a member with high heat resistance and mechanical strength. It is formed of a low lightweight member and is thermally insulated from the internal structure, and is also thermally insulated from the outer cylinder and connects and fixes the stay for attachment to the vehicle body to the internal structure via the outer cylinder. Therefore, the silencer can be firmly attached to the vehicle body without adding a load of the silencer to the outer cylinder, and the weight of the outer cylinder can be reduced, and as a result, the weight of the silencer can be reduced. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of a muffler for an internal combustion engine according to the present invention, and FIG.
It is an A sectional view. 1... Silencer, 2... Outer cylinder, 3... Cylindrical body, 4,
5, 18, 19... Heat-resistant and corrosion-resistant gasket packing, 6, 7... End plate, 10... Internal structure,
13... Partition plate, 14... Inner pipe, 17...
...Stay mounting plate, 20...Muffler stay, 22...
... Stay, 8, 21, 24 ... Bolt with heat insulation washer, 25 ... Heat insulation sound absorbing member, 30 ... Exhaust pipe,
31... Tail pipe, 33... Frame pipe.

Claims (1)

[Claims for Utility Model Registration] 1. An internal combustion engine comprising an outer cylinder and an internal structure housed in the outer cylinder and connected to the exhaust pipe of the internal combustion engine, and formed of a member with high heat resistance and mechanical strength. In the silencer, at least a part of the outer cylinder is formed of a lightweight member with low heat resistance strength, and is thermally isolated from the internal structure, and is thermally isolated from the outer cylinder and is connected through the outer cylinder. A silencer for an internal combustion engine, characterized in that a stay for attachment to a vehicle body is connected and fixed to the internal structure. 2. The silencer for an internal combustion engine according to claim 1, wherein the outer cylinder is made of an aluminum member.