JPH0536982Y2 - - Google Patents

Description

[Detailed description of the invention] <<Industrial application>> This invention relates to flexible exhaust pipes connected to the exhaust diameter of automobiles, etc., and in particular to flexible exhaust pipes for absorbing vibrations in the exhaust system extending from the engine to the body frame side. It is related to pipes.

《Prior art》 The exhaust system of automobiles, etc. is connected to the engine on the upstream side and attached to the car body frame on the downstream side, and because the vibrations on the upstream and downstream sides are different, there is a A flexible exhaust pipe made of a flexible tube as proposed in Japanese Patent No. 51432 is connected to absorb the vibration. This flexible exhaust pipe will be explained with reference to FIG.

In Fig. 3, 1 is an upstream pipe of the exhaust pipe extending from the engine side along the longitudinal direction of the vehicle;
1 is a downstream pipe extending toward the vehicle body frame, and a flexible exhaust pipe 3 is connected between the pipes 1 and 2.

The flexible exhaust pipe 3 consists of a flexible tube 4 whose both ends fit into the upstream pipe 1 and the downstream pipe 2, respectively.A wire braid 5 is placed over the flexible tube 4 to reinforce it, and both ends of the wire braid 5 are connected to the upstream pipe 2. Fixing rings 6 and 7 are placed over the side and downstream pipes 1 and 2 to fix them.

《Problem that the invention attempts to solve》 However, this flexible exhaust pipe 3
As shown in Fig. 4, at the point where the flexible tube 4 is connected to the downstream pipe 2, the downstream end 8 of the flexible tube 4 on the inner circumference is a heat point that is directly hit by the exhaust gas, which reduces fatigue strength. The decline becomes larger. Also, wire braid 5 is inserted from the outer periphery.
The problem is that muddy water or the like easily enters the fixing ring 7 on the downstream side and remains attached thereto, and therefore the flexible tube 4 is susceptible to halogen attack and corrosion due to corrosion-promoting substances contained in the muddy water. There is.

This invention has been made in view of such conventional problems, and the object is to provide a flexible exhaust pipe that can prevent strength reduction and corrosion on the downstream side of the flexible tube connected to the exhaust system.

《Means for solving the problem》 In order to achieve the above purpose, in this invention,
In a flexible exhaust pipe that connects to the exhaust system that extends in the longitudinal direction of the vehicle body, a wire braid is placed over the outer periphery of the flexible tube, and fixing rings are placed on the outer periphery of both ends to connect and fix the tube to the exhaust system.The fixing ring on the downstream side of the exhaust The lower part is enlarged in diameter to form a running wind introduction part, and a through hole for letting the running wind escape is bored in the introduction part.

<<Operation>> According to the flexible exhaust pipe having the above configuration, the running wind is introduced into the introduction part by the running wind introduction part formed with an enlarged diameter at the lower part of the fixed ring on the downstream side, and the running wind is used to blow the flexible tube. Since it is cooled, thermal fatigue strength is improved.
In addition, since a hole is formed in the introduction part, the introduced air passes through this hole, so a sufficient amount of air can be obtained, and even if muddy water that causes corrosion enters, it will not be discharged to the outside along with the running wind. Corrosion caused by halogen attack, etc. is prevented.

<<Embodiments>> Hereinafter, preferred embodiments of this invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 and 2 show an embodiment of the flexible exhaust pipe according to this invention.

First, the overall structure of the flexible exhaust pipe is as explained in FIG. 3, and the same parts as in the conventional example are denoted by the same reference numerals.

In Fig. 1, reference numeral 4 denotes a flexible tube that extends in the longitudinal direction of the vehicle body and is connected to the middle of the exhaust system.The figure shows the part that connects to the downstream pipe 2, but Connected to pipes in the same way. The inner diameter of the valley portion of the flexible tube 4 is formed to be approximately the same as that of the downstream pipe 2 (and the upstream pipe), and the end portion 4a thereof is fitted into the outer periphery of the pipe 2 and connected. A wire braid 5 is placed on the outer periphery of the flexible tube 4 to cover the entire flexible tube 4 and to reinforce the flexible tube 4.

Although the upstream side of the flexible tube 4 covered with the wire braid 5 is not shown in the figure, it is fixed to the upstream pipe with a fixing ring as in the conventional example.
The downstream side is fixed with a fixing ring 10, which is a feature of the present invention.

This fixing ring 10 has a small diameter part 11 into which the downstream pipe 2 and the wire braid 5 on its outer periphery are fitted and fixed, an inclined part 12 whose diameter is gradually enlarged from the small diameter part 11 toward the upstream side, and an inclined part 1.
2 and into which the peak of the flexible tube 4 and the wire braid 5 on its outer periphery are fitted.
3, and a traveling wind introduction part 14 whose diameter is further enlarged is formed at the lower part thereof.

As shown in FIGS. 1 and 2, this running wind introducing portion 14 is formed by the lower part of the fixed ring 10 extending from the inclined portion 12 to the large diameter portion 13 and further gradually expanding in diameter in that direction. A through hole 15 is formed in the inclined portion 12a whose diameter has been expanded.

Next, the operation of this embodiment will be explained.

First, the flexible tube 4 absorbs the difference between the vibration transmitted from the engine side to the upstream pipe and the vibration of the downstream pipe 2 by its flexibility. Further, the wire braid 5 protects the flexible tube 4 from decreasing its strength due to vibration.

The downstream end of the flexible tube 4 is in direct contact with the exhaust gas, and its outer periphery is covered with the fixing ring 10, which tends to cause a decrease in thermal fatigue strength. Since the running wind introduction part 13 is formed, the running wind flows into the introduction part 14 and blows through through the through hole 15. Therefore, due to this running wind,
The heat point 8 of the flexible tube 4 is cooled, its temperature is lowered, and a decrease in thermal fatigue strength is suppressed.

Furthermore, even if muddy water or the like enters the introduction portion 13, it is discharged from the through hole 14 along with the running wind, so the muddy water does not remain stuck and cannot be removed, and corrosion due to the muddy water is prevented.

<<Effects of the invention>> As explained above in the embodiments, according to the flexible exhaust pipe according to the invention, a traveling wind introduction part with an enlarged diameter is formed at the lower part of the fixed ring on the downstream side, and a through hole is provided in the introduction part. Since the flexible tube is bored, the temperature on the downstream side of the flexible tube can be lowered by the running wind, and its thermal fatigue strength can be improved. In addition, muddy water that has entered the lower part of the fixing ring is sucked out from the ventilation hole along with the running wind flowing through the introduction section, so it does not accumulate there.
Can prevent corrosion caused by muddy water, etc.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of essential parts showing an embodiment of the flexible exhaust pipe of the present invention, Fig. 2 is an overall view of the right side of Fig. 1, Fig. 3 is an overall view of a conventional flexible exhaust pipe, and Fig. 4 is an overall view of a conventional flexible exhaust pipe. The figure is a sectional view of the main part of FIG. 3. 2... Downstream pipe, 4... Flexible tube, 5... Wire tube, 10... Fixed ring, 14... Running wind introduction part, 15... Through hole.

Claims (1)

[Scope of utility model registration request] In a flexible exhaust pipe that connects to the exhaust system that extends in the longitudinal direction of the vehicle body, a wire braid is placed over the outer periphery of the flexible tube, and fixing rings are placed on the outer periphery of both ends to connect and fix the tube to the exhaust system.The fixing ring on the downstream side of the exhaust A flexible exhaust pipe characterized in that a lower part is enlarged in diameter to form a running wind introduction part, and a through hole is bored in the introduction part to let the running wind escape.