JPH0212262Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to a cylinder body of a muffler for an internal combustion engine.

[Conventional technology]

The exhaust system of an internal combustion engine, especially the muffler, is extremely sensitive to combustion gases, condensed water, and chemical reactions with catalysts used to purify exhaust gases, as well as temperature changes caused by driving patterns. It is easily corroded by. In particular, when the muffler is located at the rear end of a passenger car, corrosion appears to be the main cause since the temperature of the exhaust gas is relatively low.

Furthermore, looking at the causes of these corrosions, as mentioned above, there are cases in which corrosion occurs from within, and cases in which corrosion occurs externally, that is, in the destination area, due to salt damage, moisture damage, etc.

Conventionally, countermeasures against these problems include the use of surface-treated steel plates and structures that actively drain condensed water.

On the other hand, the cylindrical body generally has a double or triple structure in many cases due to considerations such as processability during molding or transmitted sound.

[Problems to be solved by the invention] Broadly speaking, there are two types of methods for forming the multiple cylinders. One method is to overlap two (or three) plates in advance at the point of flatness and crimp them. In this case, it is possible to use corrosion-resistant material only in the necessary parts (inner or outer cylinder), but if stainless steel or the like is used as the corrosion-resistant material, there is a disadvantage that the jigs and tools will be subject to severe wear due to the hardness of the material. Another method is to wrap a single plate in a spiral shape and fix the ends with spots, etc., but in this case, the inner and outer cylinders are made of the same material, so if you use corrosion-resistant material for it, the material cost will be high. This results in excessive quality.

Furthermore, even if materials with corrosion-resistant surface treatment or corrosion-resistant steel are used, when the internal structure consisting of partition plates and other parts is press-fitted into the cylinder, the wall surface of the cylinder will be scratched, leaving scars. be.

The present invention aims to solve these problems.

[Means to solve the problem]

In the present invention, the inner and outer cylinders 3 and 1 are molded separately, and the inner structure with the circular partition plate 6 is assembled while the inner cylinder 3 is kept wrapped without joining the mating surface 4. The inner cylinder 3 is expanded by integral caulking connection 9 with the end plate 8 at the edge of the outer cylinders 3 and 1, and the outer cylinder 1 is assembled.
This is a silencer for internal combustion engines that is tightly attached to the inner surface of the engine.

[Effect]

With the above structure, the inner/outer cylinders and the internal structure can be subjected to anti-corrosion treatment and then combined and bonded together.

〔Example〕

In FIG. 1, 1 is an outer cylinder made of a material plate formed into a cylindrical shape and the mating surfaces 2 are caulked together, and 3 is a material plate different from the outer cylinder 1, which has a slightly larger diameter than the outer diameter of the circular partition plate 6. This figure shows an inner cylinder which is rolled into a rough cylindrical shape and slidably wrapped without joining the mating surfaces 4.

FIG. 2 shows an example in which the mating surfaces of the outer cylinder 1 are welded 5.

As shown in FIG.
and the like, and the edges of the inner and outer tubes 1 and 3 are caulked together 9 using the end plate 8, and the lap portion of the mating surface 4 of the inner tube 3 slides and spreads out. It is tightly fixed to the cylinder 1 as shown in Fig. 4.

As for the order, when the inner cylinder 3 is pushed into the outer cylinder 1 after assembling the internal structure to the inner cylinder 3, the inner cylinder 3 is pushed out in the vicinity where the circular partition plate 6 is located, but the end Since the mating surfaces facing the outer cylinder are still in a lapped state, the outer cylinder can be inserted without scratching the inner wall surface of the outer cylinder. Then, when both ends are integrally connected by the end plate 8, the inner cylinder 3 is connected to the outer cylinder 1 over the entire length.
It is closely related to.

After being assembled in this way, the inner and outer cylinders 1 and 3 may be partially fixed by spot welding, if necessary. Further, it is preferable that the mating surfaces 4 and 5 of the inner and outer cylinders be located far apart, for example, on diametrically opposite sides, as shown in the second figure.

[Effect of idea]

With the above configuration, the inner and outer cylinders can be formed from different types of plate materials as required. In addition, by applying anti-corrosion coating to the inner cylinder and internal structure, it is possible to process the entire internal area, which eliminates the scratches mentioned above when assembling them. This has the advantage of being able to provide inexpensive products without using corrosion-resistant steel plates.

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views of the cylindrical body of the silencer of the present invention, Figure 3 is a schematic diagram of the left half of the silencer with the internal structure and end plate assembled, and Figure 4 is a cross-sectional view of the cylinder body of the silencer of the present invention. A partially enlarged cross-sectional view. 1... Outer cylinder, 2, 5... Its mating surface joint part,
3... Inner cylinder, 4... Its lap mating surface, 6...
Partition plate, 8...end plate.

Claims (1)

[Scope of utility model registration request] The inner and outer cylinders are molded separately, and while the inner cylinder remains wrapped without joining the mating surfaces, the internal structure with the circular partition plate is assembled, and the inner structure with the end plate on the edge of the inner and outer cylinders is assembled. A silencer for internal combustion engines in which the inner cylinder is expanded and tightly attached to the inner surface of the outer cylinder by integral caulking.