JPS6314017Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a bellows-type exhaust pipe used in an automobile exhaust system.

Automobile exhaust pipes are usually long because the exhaust gas from the engine mounted at the front of the car is exhausted from the rear of the car, so vibrations from various parts of the car are transmitted from the fixed members of the exhaust pipe to the exhaust pipe. As a result, different vibration stresses are applied to various parts of the exhaust pipe, resulting in a decrease in durability.

Therefore, in the middle of the exhaust pipe, there are connection parts 7 and 8 connected to the exhaust pipe at both ends as shown in FIG. A bellows-type exhaust pipe 2 having blades 11 is inserted to absorb different vibrational stresses transmitted to various parts of the exhaust pipe by the bellows 10 of the bellows-type exhaust pipe 2. The bellows 10 is thermally shielded by the heat shield 9,
Further, a method is adopted in which the bellows 10 is protected and heat shielded by a blade 11 formed by knitting a plurality of metal wires in a cross shape.

By the way, the heat shield 9 described above also has the following functions.

That is, in the case of a bellows type exhaust pipe, the turbulent flow of exhaust gas can cause the bellows to resonate, resulting in abnormal noise (such as a beeping sound).

Therefore, by providing a heat shield 9 inside, the resonance is prevented by its buffering effect.

Since the heat shield 9 is installed inside the bellows in this way, it is required to have the same durability level as the bellows and sufficient displacement absorption, and it must also be able to avoid abnormal noise due to itself. It is not allowed to occur.

However, in the case of a structure like the conventional example mentioned above, if it is made to be flexible enough to absorb displacement, it is necessary to avoid the generation of abnormal noise from the metal contact part. There was a structural problem.

Therefore, in order to deal with these problems, this invention uses a spiral tube structure that minimizes the mutual contact surface, so that no abnormal noise is generated.
This problem has been solved by providing a heat shield with high displacement absorption.

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

As shown in Fig. 2, the main parts of an automobile exhaust system consist of an engine 1, a bellows type exhaust pipe 2, a catalytic converter 3, a muffler 4, etc., and these main parts are connected through exhaust pipes 5. Exhaust gas from the engine 1 passes through a bellows type exhaust pipe 2, a catalytic converter 3, and a muffler 4, and is discharged from a tail pipe 6 of the muffler 4.

In FIG. 3, the bellows type exhaust pipe 2 has connection parts 7 and 8 at both ends, for example, inner rings 7a and 8a and an outer ring 7.
b, 8b, both inner rings 7a, 8a are connected via a bellows 10, and a heat shield 12, which will be described later, is arranged in parallel between both inner rings 7a, 8a on the inside corresponding to the bellows 10. This bellows 10
A blade 11 is provided to protect the inner and outer rings 7a, 7b,
It is clamped by 8a and 8b, and the middle main part is 3 parts 12 and 1
It consists of a triple structure of 0,11. Further, the bellows type exhaust pipe 2 is fixed to the exhaust pipes 5, 5 by inserting the exhaust pipes 5, 5 into the end ports of the inner rings 7a, 8a and by means such as welding (not shown).

An example of the most preferable structure of the heat shield 12 applied to the bellows type exhaust pipe 2 having such a triple structure is shown in FIG. This is shown in Figure 3.

In FIG. 4, the heat shield 12 is made of a thin metal strip plate made of, for example, SUS material, which has a stepped portion along the approximately central portion in the longitudinal direction so as to have flexibility and stretchability. It is constructed by overlapping and winding spirally so as to maintain the same height.

According to this invention, since the heat shield 12 has a spiral tube structure with a reduced mutual contact surface,
This makes it possible to sufficiently maintain the displacement absorption ability and to prevent the generation of abnormal noise as much as possible when absorbing the displacement.

[Brief explanation of drawings]

Figure 1 is a partially cutaway side view showing a conventional bellows-type exhaust pipe, Figure 2 is a schematic diagram of an automobile exhaust system incorporating this invention, and Figure 3 is a partial view of the bellows-type exhaust pipe of this invention. FIG. 4 is a partially cutaway side view showing the main parts of the heat shield of this invention. Code, 2... Bellows type exhaust pipe, 7, 8... Connection part, 10... Bellows, 11... Blade, 1
2...Heat shield.

Claims (1)

[Scope of utility model registration request] In a bellows-type exhaust pipe, which has a connection part with the exhaust pipe at both ends, a heat shield is disposed between the connection parts, and a bellows and a blade are arranged in order outward from the heat shield. A bellows type exhaust pipe has a configuration in which a thin metal strip plate having a stepped portion along a substantially central portion is spirally wound so that the inner and outer circumferential surfaces thereof maintain the same height.