JPS636414Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Field of Application> The present invention relates to a connection device for an exhaust pipe of an engine mounted on an automobile or the like.

<Conventional technology> The exhaust pipe system of the engine installed in automobiles, etc.
For example, as shown in FIG. 1, an exhaust pipe 31 with flanges 41 and 42 welded all the way around both ends from the exhaust manifold 2 of the engine 1, and a flange 42 with a flange 43 welded all the way around one end, and an exhaust brake. It consists of an exhaust pipe 32 with a valve 5 interposed therein, and an exhaust pipe 33 connected to the rear end of the exhaust pipe 32 via a muffler 6. In addition, 71 and 72 are the above-mentioned silencers 6.
This is a support member that supports the frame or vehicle body (not shown).

In such an exhaust pipe system, the exhaust pipe 31 and the exhaust brake valve 5 are supported by the engine 1 side, while the exhaust pipe 32 is supported by the engine side and the chassis frame. tube 3
2 is extremely severe in terms of strength due to the relative displacement between the engine 1 and the chassis frame, which have different vibration systems.
In particular, the flange 4 on which the exhaust brake valve 5 is attached
There was a risk that cracks would occur in the welded part with No. 3.

Conventionally, in order to solve this problem, the wall thickness of the exhaust pipe 32 has been increased, but this increases the weight and rigidity, which necessitates an increase in the strength of the support device for the exhaust pipe to the frame. In this respect, the weight also increased.

As a means to solve this type of problem, for example, as shown in Japanese Utility Model Publication No. 54-31221, one end of the reinforcing pipe fitted around the outer periphery of the exhaust pipe is attached to the end of the exhaust pipe, and the central part of the outer periphery of the reinforcing pipe is reinforced. One idea is to weld the entire circumference of each extension to the end of a flange joint fitted around the outer periphery of the pipe end.

<Problems to be solved by the invention> However, in the above-mentioned Jikosho, the stress and vibration transmission path of the exhaust pipe runs from the end of the exhaust pipe through the reinforcing pipe to the flange joint from near the center of the exhaust pipe,
Because it is a long path that connects the reinforcing pipe and flange joint almost in series, it is not only excessively flexible and weak against bending, but also has a large change in cross-sectional area, especially between the flange joint and the reinforcing pipe. , and because the welding during this time is all-around welding, stress concentration may occur and cracks may occur.

In view of the above points, it is an object of the present invention to provide an exhaust pipe connecting device that increases strength, moderately lowers rigidity, and disperses stress, especially when connecting an exhaust pipe and a flange. .

<Means for solving the problems> The configuration of the present invention for achieving the above object will be explained with reference to FIG. 2 corresponding to the embodiment.
A flange 43 is provided at the end of the exhaust pipe 32, and a cylindrical body 8, which is thinner than the exhaust pipe 32, is press-fitted onto the outer periphery of the exhaust pipe 32 without being joined to the flange 43. The leg portions 91 thus formed are fitted onto the flange 43 and a truss-shaped reinforcing tube 9 that is slightly shorter than the cylindrical body 8 is welded to the flange 43, and plug welded 10 to the cylindrical body 9 near the end opposite to the flange 43. It is what it is.

<Function> The strength of the vicinity of the end of the exhaust pipe 32 is increased by the cylindrical body 8 and the truss-shaped reinforcing pipe body 9, and the force applied to the exhaust pipe 32 via the flange 43, for example, is reduced. The stress is distributed through the end of the exhaust pipe 32 and the flange-like reinforcing pipe body 9, via the cylindrical body 8, and at points away from the flange 43, and at this time, stress is not concentrated due to plug welding. Further, vibrations are attenuated by a frictional damping effect between the cylinder body 8 and the exhaust pipe 32.

<Embodiment> Below, an embodiment of the present invention will be described based on FIG.
has been done.

A cylindrical body 8 has an inner diameter that fits into the exhaust pipe 32 by press fitting, covers the end of the exhaust pipe relatively long, and is thinner than the wall thickness of the exhaust pipe 32. With the above configuration, a sudden change in cross-sectional area at the end of the exhaust pipe 32 can be alleviated, and local stress concentration can be avoided.

Reference numeral 9 denotes a reinforced tubular body in the shape of a flap, which has several notches 92 formed at the expanded end to form a plurality of legs 91, and has an inner diameter that is fitted into the cylindrical body 8, and a length that is slightly shorter than the cylindrical body 8. The tip of the leg 91 is welded to the side surface of the flange 43.

Reference numeral 10 indicates plug welding, and welding is performed at constant pitches on the circumference of the lattice-shaped reinforcing tube body 9 [commonly speaking, points with low stress (on the circumference, the apex is 0°, 45°, 135°, 225°, and 315°) )], and the cylinder body 8 is welded at this hole.

The connection part of the present invention is constructed as described above.
The assembly order will be explained below.

First, a cold-expanded cylinder 8 is press-fitted into the end of the exhaust pipe 32 at a distance equal to or more than the thickness of the flange 43, and then a truss-shaped reinforcing pipe 9 is fitted into the cylinder 8. After fitting and positioning the rattle-shaped reinforcing tube body 9 to the right in the figure from the normal state shown in the figure, the outer periphery of one end of the exhaust pipe 32 is welded 11 to the inner diameter side surface of the flange 43.

Next, after moving the latspa-shaped reinforcing tube body 9 to the left to the state shown in the figure, the leg portion 9 formed at one end thereof is
1 is welded 12 to the side surface near the outer periphery of the flange 43, and the other end is plug welded 10 to the outer periphery of the cylindrical body 8, thereby completing the assembly.

In the connecting device of the present invention having the above configuration, the strength of the vicinity of the end of the exhaust pipe 32 is increased by the cylindrical body 8 and the tongue-shaped reinforcing pipe body 9, and the exhaust pipe 32 is connected to the exhaust pipe 32 via the flange 43, for example. Such force is applied in a distributed manner to a point away from the flange 43 via the end of the exhaust pipe 32 and the flange-like reinforcing pipe body 9, via the cylinder body 8, and at this time, it is applied by plug welding. Stress will not be concentrated on the welded portion. Further, vibrations are damped by a frictional damping effect between the cylinder body 8 and the exhaust pipe 32.

<Effects of the invention> As described above, the present invention provides a flange at the end of the exhaust pipe, press-fits a cylindrical body thinner than the exhaust pipe to the outer periphery of the exhaust pipe without being joined to the flange, and
A leg portion formed at an enlarged end on the outer periphery of the cylinder body is fitted with a truss-shaped reinforcing pipe body slightly shorter than the cylinder body, which is welded to the flange, and plug-welded to the cylinder body near the end opposite to the flange. Therefore, the cross-sectional area of the exhaust pipe end increases stepwise toward the end, and the strength of the exhaust pipe end can be effectively increased.

In addition, since the cylindrical body is integrally formed with the exhaust pipe by press-fitting instead of welding, the exhaust pipe is not affected by heat due to welding except for the ends, and therefore, cracks are prevented from forming at the welded parts. can be prevented.

Further, with the above configuration, vibrations of the exhaust pipe are attenuated by a frictional damping effect between the exhaust pipe and the cylindrical body, and thermal expansion of the exhaust pipe can be smoothly absorbed between the exhaust pipe and the cylindrical body. The vibration and thermal expansion at this time have no effect on the strap-shaped reinforcing tube, and there is no risk of damaging the strength of the strap-shaped reinforcing tube.

Furthermore, in the present invention, the other end of the truss-shaped reinforcing tube, in which the legs formed at the expanded end are welded to the flange,
By fitting into the cylinder and plug welding,
The rigidity of the entire device can be maintained at an appropriate level without becoming excessively low, and vibrations and stress are distributed and transmitted to the flange without being concentrated on the exhaust pipe, thus preventing damage to the exhaust pipe from the joint with the flange. There is no risk of it happening. Furthermore, the plug welding has the effect of preventing stress from concentrating on the welded area and preventing cracks from forming, compared to welding the entire circumference.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an exhaust pipe system of an engine mounted on an automobile, and FIG. 2 is a partially cutaway front view of the exhaust pipe equipped with the connecting device of the present invention. 31, 32, 33; Exhaust pipe, 41, 42, 4
3; flange, 5; exhaust brake valve, 8; cylinder body,
9; Ruppa-shaped reinforcing pipe body, 91; Leg, 92; Notch, 10; Plug welding, 11, 12; Welding.

Claims (1)

[Scope of utility model registration request] A flange is provided at the end of the exhaust pipe, a cylindrical body thinner than the exhaust pipe is press-fitted to the outer periphery of the exhaust pipe without being joined to the flange, and legs formed at enlarged ends on the outer periphery of the cylindrical body are attached to the flange. An exhaust pipe connection device comprising a rattle-shaped reinforcing pipe body that is slightly shorter than the welded cylinder body and plug-welded to the cylinder body near the end opposite to the flange.