JPS6229619Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention mainly relates to a mounting structure for a rear end decorative plate in an insertable muffler for a two-wheeled motor vehicle, and is aimed at improving productivity when mass producing mufflers.

In a conventional insertion type muffler, as shown in FIG. 1, the buttful assembly 2 is generally press-fitted from the rear into a tapered outer cylinder 1 that becomes thicker toward the rear (right side of the figure), and at the rear end of the muffler, The end plate 3 of the buttful assembly 2 is fixed by welding to the ring 4, and then a black heat-resistant coating (the coating is indicated by 5) is applied to the rear surface of the end plate 3 to improve its corrosion resistance and appearance. There is. The ring 4 is an annular body that expands in two stages toward the rear (right side in Figure 1), and has a large diameter portion 4.
The outer peripheral surface of a is pressed against the inner surface of the rear end opening of the outer cylinder 1,
The rear end edge 6 of the outer tube 1 is caulked to the inner surface of the large diameter portion 4a, so that the ring 4 is integrated with the outer tube 1.
The outer peripheral surface of the small diameter portion 4b of the ring 4 is spaced inward from the inner surface of the outer cylinder 1, and the tapered portion 7 provided on the outer periphery of the end plate 3 is in pressure contact with the inner surface of the small diameter portion 4b, so that the rear edge of the joint Arc welding is applied to the entire circumference of the portion 8. One embodiment of a conventional buttful assembly will now be described. The illustrated buttful assembly 2 includes a tail pipe 11 fitted and welded to a central cylindrical flange 10 of an end plate 3, and a tail pipe 1.
Two partition walls 12 and 13 fitted and welded to the front half of 1
An annular gap 14 is formed between the outer peripheral edge of the partition wall 13 and the outer cylinder 1, and a cylindrical flange 15 on the outer periphery of the partition wall 12 is in pressure contact with the tapered inner surface of the outer cylinder 1. The flange 15 has a plurality of slits 16 that open toward the front, which allows the flange 1
5 elastically fits into the inner surface of the outer cylinder 1. The tail pipe 11 is divided into front and rear parts by a partition wall 17, and the front end opens into the first chamber 18, the part in front of the partition wall 17 communicates with the second chamber 20 through a hole 19, and the part behind the partition wall 17 communicates with the second chamber 20 through a hole 21. It communicates with the third chamber 22 through. Solid arrows indicate the direction of flow of exhaust gas.

As shown in Fig. 1, if a method is adopted in which the joint part 8 of the end plate 3 and ring 4 is welded after the buttful assembly 2 is press-fitted into the outer cylinder 1, the rear part 5 of the end plate 3 is painted after the muffler is assembled. In order to apply this, there are many restrictions on the type and method of painting, and jigs for painting are also required. That is, since the outer cylinder 1 has been plated in advance, it is impossible to bake heat-resistant paint onto it, and when applying spray painting, masking etc. are required, and when using a brush, it is time-consuming. In this way, when painting is performed after assembling the muffler, the problem that productivity deteriorates cannot be avoided.

This invention aims to avoid the above-mentioned problems when painting is applied after muffler assembly.A heat-resistant painted annular decorative board is fixed to the rear surface of the end plate, and the outside diameter of the decorative board is made larger than the outside diameter of the welded part. The welded part is not visible from the rear of the muffler, and an embodiment is shown in FIG. The decorative board 25 in Fig. 2 is, for example, a member punched out of SPC material (iron plate) into an annular shape, press-molded into an S-shaped cross section at the same time, and then baked and painted with black heat-resistant paint. It is fastened with rivets 26. The rivets 26 are arranged at equal intervals on the same circumference, and three to four rivets, for example, are suitable. The inner diameter D ₁ of the decorative plate 25 is slightly larger than the inner diameter of the tail pipe 11, so the decorative plate 25 does not provide resistance to the exhaust gas discharged from the tail pipe 11.

The outer diameter D ₂ of the decorative plate 25 is slightly larger than the diameter D ₃ of the welded portion 8, so that the welded portion 8 is not visible from the rear of the muffler.

When the decorative board mounting structure shown in Fig. 2 is adopted, the decorative board 25 can be coated with heat-resistant paint as a single item, and since the decorative board 25 is small in size, it has excellent corrosion resistance, peeling resistance, and gloss. Various types of painting, such as with or without, are possible, and the rear end of the muffler can be treated much more easily than when painting after the muffler is assembled.

The blind rivet 26 has been widely used in the past, and when using this blind rivet 26, the decorative board 25 is applied from the rear to the end plate 3 after the muffler is assembled, and the end plate 3 and the decorative board 25 are opened. After aligning the rivet holes, blind rivets 26 can be driven in from the rear. When using the blind rivet method, welding part 8
The outer diameter of the decorative board 25 can be increased so that it can be completely covered from the rear, and the appearance from the rear is further improved. There may be a small amount of plating liquid left inside the outer cylinder 1, and after assembling the muffler, the outer cylinder 1
Droplets may adhere to the inner surface of the baffle assembly 2 and the plating liquid or droplets may flow down the lower half of the rear surface of the end plate 3 through the tail pipe 11 and cause stains. If the method of fixing the plate 25 later with blind rivets 26 is adopted, the decorative plate 25 can be attached immediately before shipping, which has the advantage of maintaining high commercial value. The workability of welding the portion 8 is improved, and the work of attaching the decorative plate is simple, making it suitable for mass production.
Furthermore, by changing the shape of the decorative plate 25 in various ways, it is easy to freely change the design regardless of the muffler body.

In addition to motorcycles, the present invention can also be applied to snowmobiles, other vehicles, agricultural working machines, and the like.

[Brief explanation of the drawing]

Figure 1 is a vertical sectional side view showing the conventional structure;
FIG. 2 is a vertical sectional side view of an insertable muffler for a two-wheeled motor vehicle to which the present invention is applied, and FIG. 3 is an enlarged sectional view showing the procedure for installing a blind rivet. 1...
Outer tube, 2... Bound full assembly, 3... End plate, 8... Welded part, 25... Decorative plate, 26...
...Rivets, 26...Blind Rivets.

Claims (1)

[Scope of utility model registration request] In an insertion type muffler in which a buttful assembly is press-fitted from an opening at the rear end into a tapered outer cylinder that becomes thicker toward the rear, and an end plate at the rear end of the buttfull assembly is welded to the inner surface of the opening at the rear end of the outer cylinder, An insertion-type muffler characterized by fixing a heat-resistant painted annular decorative plate to the rear surface of the end plate, and making the outer diameter of the decorative plate larger than the outer diameter of the welded part so that the welded part is not visible from the rear of the muffler. Rear end decorative plate mounting structure.