JPH0248656Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to an exhaust pipe expansion joint, and in particular, the invention includes an accordion-shaped metal bellows and an inner cylinder disposed inside the metal bellows. This invention relates to an exhaust pipe expansion joint that allows exhaust gas to pass through a space.

[Prior art and its problems]

Generally, this type of exhaust pipe expansion joint is constructed as shown in FIG.

The exhaust pipe expansion joint shown in FIG. 2 is applied, for example, to a large or medium-sized diesel engine (or gasoline engine), and the flange 15 at one end is bolted to the exhaust manifold pipe (not shown) of the diesel engine. 21, and the flange 16 at the other end is fixed to an exhaust pipe (not shown) with bolts 22.

Between the flange 15 and an auxiliary flange 23 provided integrally with the flange 16, metal bellows 17, 17 having a spacer 19 in the middle are attached, and inside the metal bellows 17, 17, the flange 16 and the auxiliary flange 23 are installed. An inner cylinder 18 fixed to the auxiliary flange 23 is arranged, and metal bellows 17, 17
A cover 20 attached to an auxiliary flange 23 is provided on the outside.

The exhaust pipe expansion joint configured as described above guides the high-temperature exhaust gas discharged from the diesel engine to the exhaust pipe according to the arrow shown in Figure 2 in order to release it into the atmosphere. At this time, displacement due to thermal expansion, vibration, etc. of the exhaust manifold pipe to which the flange 15 is fixed and the exhaust pipe to which the flange 16 is fixed is absorbed by the metal bellows 17, 17.

However, in such a conventional engine, a part of the exhaust gas discharged from the diesel engine flows into the gap between the lower end of the inner cylinder 18 and the flange 15, as shown by arrow A in FIG. Through the space 2 between the metal bellows 17, 17 and the inner cylinder 18
4, it is unavoidable that space 2
The exhaust gas that has entered into the metal bellows 17, 17
The sulfuric acid produced by the sulfur content and moisture in the exhaust gas is deposited on the surface of the metal bellows 1.
7 and 17, resulting in gas leakage in a short period of time.

The purpose of this invention is to provide an exhaust pipe expansion joint which can prevent corrosion of the metal bellows caused by exhaust gas by solving the problems of the conventional ones as described above.

[Means for solving problems]

In order to solve the above-mentioned problems, this invention includes a bellows-shaped metal bellows, an inner cylinder disposed inside the metal bellows, and a flange to which the metal bellows is attached. In an exhaust pipe expansion joint in which exhaust gas passes through the internal air, an annular sealing member having a cross section of approximately Ω shape is installed in an annular space formed between the metal bellows and the inner cylinder. With the outer circumference side facing the flange,
Further, a means is employed in which the inner circumferential side is fixed to the inner cylinder side and closed.

[Effect]

Since this invention employs the above-mentioned means, the annular sealing member prevents exhaust gas from entering the space formed between the metal bellows and the inner cylinder.

〔Example〕

Embodiments of this invention shown in the drawings will be described below.

FIG. 1 shows an embodiment of the exhaust pipe expansion joint according to this invention, and this exhaust pipe expansion joint has the following features:
For example, it applies to large or medium-sized diesel engines (or gasoline engines),
The flange 1 at one end is fixed to an exhaust manifold pipe (not shown) of a diesel engine with bolts 7, and the flange 2 at the other end is fixed to an exhaust pipe (not shown) with bolts 8.

Between the flange 1 and an auxiliary flange 10 provided integrally with the flange 2, metal bellows 3, 3 having a spacer 5 in the middle are attached, and inside the metal bellows 3, 3, the flange 2 is attached. And an inner cylinder 4 fixed to the auxiliary flange 10 is disposed, and a cover 6 attached to the auxiliary flange 10 is provided on the outside of the metal bellows 3,3.

Further, at the open end of the annular space 11 formed between the metal bellows 3, 3 and the inner cylinder 4, an annular sealing member 9 having an Ω-shaped cross section and made of a material with excellent heat resistance and elasticity is provided. It is provided.

That is, the outer circumferential portion of the sealing member 9 is fixed to the inner circumferential surface of the end fitting 3a of the metal bellows 3 attached to the flange 1 by welding or bolts, and the inner circumferential portion of the sealing member 9 is fixed to the inner circumferential surface of the end fitting 3a of the metal bellows 3 attached to the flange 1. It is fixed to the outer peripheral surface of the cylinder 4 by welding or bolts.

With these, the open end (lower end) of the space 11
is sealed to prevent exhaust gas from entering the space 11 through the gap between the lower end of the inner cylinder 4 and the flange 1.

Next, the operation of the above will be explained.

First, high-temperature exhaust gas discharged from a diesel engine is guided into the exhaust pipe and released into the atmosphere according to the arrow shown in Figure 1, and at that time, the flange 1
Displacement due to thermal expansion, vibration, etc. of the exhaust manifold pipe to which the flange 2 is fixed and the exhaust pipe to which the flange 2 is fixed is absorbed by the metal bellows 3, 3.

Since the open end (lower end) of the space 11 formed between the metal bellows 3, 3 and the inner tube 4 is sealed by the sealing member 9, the lower end of the inner tube 4 and the flange 1 are sealed. Exhaust gas attempting to enter the space 11 through the gap between the two is prevented from entering the space 11 by the sealing member 9.
Therefore, sulfuric acid generated by the sulfur content and moisture in the exhaust gas is prevented from corroding the metal bellows 3, 3.

Moreover, even if the metal bellows 3, 3 and the inner cylinder 4 are displaced relative to each other due to thermal expansion and vibration of the exhaust manifold and exhaust pipe, the sealing member 9 will not be able to resist the radial displacement even in the axial direction. The displacement is also followed by an increase or decrease in the radius of curvature of the curved portion. Therefore, even after long-term use, there is no risk that the sealing performance between the inner tube 4 and the flange 1 will be impaired, and excellent sealing performance can always be obtained.

Although the above embodiments have been described as being applied to exhaust gas, the present invention is not limited thereto and can of course be applied to other gas bodies or fluids such as powder.

[Effect of idea]

By configuring this idea as described above,
The sealing member can prevent exhaust gas from entering the space formed between the metal bellows and the inner cylinder, and therefore prevents the exhaust gas from entering the space formed by the sulfur content and moisture in the exhaust gas. Can prevent sulfuric acid from corroding metal bellows,
As a result, a high-quality exhaust pipe expansion joint that does not cause gas leakage over a long period of time can be obtained, which has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of an exhaust pipe expansion joint according to this invention, and FIG. 2 is a sectional view showing an example of a conventional exhaust pipe expansion joint. 1,15...Flange, 2,16...Flange, 3,17...Metal bellows, 4,18...Inner cylinder, 5,19...Spacer, 6,20...Cover, 7,21...Bolt , 8, 22...volts,
9... Sealing member, 10, 23... Auxiliary flange,
11, 24... Space portion, 3a... End fitting.

Claims (1)

[Scope of utility model registration request] Concert-shaped metal bellows 3, 3, an inner cylinder 4 disposed inside the metal bellows 3, 3, and flanges 1, 10 to which the metal bellows 3, 3 are attached.
and an annular space 11 formed between the metal bellows 3, 3 and the inner cylinder 4 in an exhaust pipe expansion joint that allows exhaust gas to pass through the inner space of the inner cylinder 4. An annular sealing member 9 having a substantially Ω-shaped cross section is arranged and closed with its outer circumferential side fixed to the flange 1 side and its inner circumferential side fixed to the inner cylinder 4 side. Pipe expansion joint.