JPS6233948Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a bellows-type exhaust pipe that can be effectively utilized by being applied mainly to an automobile exhaust pipe system.

The exhaust pipe system of a current common automobile is constructed as shown in FIG. That is, in this figure, exhaust from an engine 1 is guided by a front pipe 2 and a flexible exhaust pipe 3 to a catalytic converter 4, a pre-muffler 6, and a main muffler 7, which are connected by a sensor pipe 5, and then to a tail pipe 8. It's getting more exhaust.

By the way, in the case of this type of method,
As the flexible exhaust pipe 3, a bellows pipe is used for vibration resistance and reduction of transmitted sound. However, bellows tubes with conventional structures no longer satisfy the specifications required in recent years for vibration absorption and transmitted sound damping effects.

Therefore, the present inventors formed a single thin-walled strip material into a corrugated strip material as shown in Fig. 2 (a), and continuously wound this strip material in a spiral as shown in Fig. 2 (b). A multi-layer spiral bellows type exhaust pipe using a multi-layer spiral bellows constructed by the above was devised, and this was used as the flexible exhaust pipe 3 to solve the above-mentioned drawbacks.

However, the reality is that in this industry, the aim is to create cars that are quiet and comfortable to ride, and there is a demand for products that are even better at reducing noise and vibration.

This invention is an attempt to improve the conventional multilayer spiral bellows type exhaust pipe, thereby providing a polymerized multilayer spiral bellows type exhaust pipe that is even more excellent in reducing noise and vibration.

Hereinafter, specific embodiments of this invention will be described based on the drawings.

FIG. 3 shows an embodiment of the polymerized multilayer spiral bellows type exhaust pipe according to this invention, which is used as a flexible exhaust pipe 3.

That is, first, a thin stainless steel strip made by folding a single plate and stacking two sheets is roll-formed into the desired corrugated strip (Fig. 3 A), and then this strip is continuously spirally formed into multiple layers. This polymerized multilayer spiral bellows type exhaust pipe is constructed by winding and overlapping. In the example, three layers are spirally wound, so there are six layers in total. Therefore, for example, if one thin strip with a thickness of 0.15 mm is used, the thickness of the two folded thin strips will be 0.3 mm, and after forming this into a corrugated strip, the thickness will be 0.3 mm. Since the exhaust pipes are spirally wound, the thickness of the main exhaust pipe is 0.9mm.

Furthermore, if the flexible exhaust pipe 3 is coated with a braided wire 9 as shown in FIG. 1, the heat shielding effect will be further increased, and the multilayered spiral bellows type exhaust pipe will be protected.

As is clear from the above explanation of the configuration, the following excellent effects can be expected with this invention.

In other words, this exhaust pipe is a flexible exhaust pipe 3 in an automobile exhaust system, which is made by folding back one plate.
Since the thin-walled strip material is formed into a corrugated strip material and is constructed by stacking the thin-walled strip material in multiple layers spirally, it is possible to form a single thin-walled strip material in the same way and spirally wind it as in the past. Compared to a multi-layered spiral bellows type exhaust pipe, a larger number of layers can be molded at once, and the processing time until the desired number of layers is formed can be shortened. Furthermore, compared to the method of stacking several sheets to form a corrugated strip, the present invention folds one sheet to form two sheets, so it will not shift during forming. In particular, since this exhaust pipe has a spiral wave cross-sectional shape,
Exhaust gas from the engine swirls, making the pulsation uniform and reducing noise, and the high-temperature, high-pressure exhaust gas repeatedly expands and contracts through the peaks and valleys of the bellows, causing interference and creating a resonance chamber. It also has an effect that cannot be obtained with the conventional straight pipe system, which attenuates sound energy through a resonance effect. In turn, the main muffler can be made smaller and lighter by reducing the number of bulkheads, and by reducing the number of bulkheads in the main muffler, exhaust resistance is reduced, which increases engine output and can be expected to have the secondary effect of saving fuel. .

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the exhaust pipe system, Figure 2A is a perspective view of the main part of the corrugated strip of a conventional multilayer spiral bellows type exhaust pipe used in a flexible exhaust pipe, and Figure 2B is the same exhaust pipe. FIG. 3A is a perspective view of the main part of the corrugated strip of the overlapping multilayer spiral bellows type exhaust pipe according to the invention, and FIG. 3B is a sectional view of the main part of the exhaust pipe. Code, 1...Engine, 3...Flexible exhaust pipe,
8...Tail pipe.

Claims (1)

[Scope of utility model registration request] In the flexible exhaust pipe 3 inserted into the exhaust pipe system extending from the engine 1 to the tail pipe 8, one plate is folded back to form a two-ply corrugated strip as the flexible exhaust pipe 3. In addition, a bellows-type exhaust pipe is characterized in that a bellows-type exhaust pipe is formed by spirally winding the corrugated strips in multiple layers.