JPS5999023A - Exhaust-gas purifying apparatus for internal-combustion engine for motorcycle - Google Patents

Abstract

PURPOSE:To provide an apparatus for purifying exhaust gas by feeding secondary air into exhaust passages of an internal-combustion engine, which can be arranged compactly on a vehicle body by feeding secondary air into the exhaust passages via a pipe frame of the vehicle body. CONSTITUTION:Cylinders 1A-1D of an internal-combustion engine 1 are arranged in a V-shape: two at the front and two at the back. Exhaust passages 7 of the front cylinders 1A, 1B are opened downward at a position near a down- pipe 4a of a vehicle frame 4 while exhaust passages 7 of the rear cylinders 1C, 1D are opened backward. On the other hand, intake passages 2 of the cylinders 1A-1D are respectively communicated with an intake-air distributing chamber 6 of an air cleaner 5. In such an arrangement, check valves 11 disposed on the opposite sides of the lower surface of the intake-air distributing chamber 6 and the exhaust passages 7 for the front cylinders 1A, 1B are communicated with each other via respective down-pipes 4a. Since, with such an arrangement, the secondary air can be supplied into the exhaust passages 7 from the down- pipes 4a, it is made unnecessary to provide a special piping for feeding the secondary air.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust gas purification device for an internal combustion engine such as a motorcycle.

This type of internal combustion engine is known to be equipped with an exhaust purification device that reduces air pollutants such as unburned gas in the exhaust gas by supplying secondary air to the exhaust passage of one engine.

The object of the present invention is to compactly arrange this type of exhaust purification device in the body of a motorcycle or the like, and the secondary air is guided to the exhaust passage of the engine through the pipe frame of the vehicle body. It is characterized by

The illustrated example is applied to a motorcycle equipped with a water-cooled OHC (overhead camshaft) VfJ114-cylinder internal combustion engine 1.

As shown in FIG. 1, the cylinders 1A to 1D of the engine 1 are arranged in a V-shape, two in the front and two in the front, and the intake passages 2 open inward from each other. It communicates with the air intake distribution chamber B of the air cleaner 5 provided at the front upper part of the air cleaner 4 (FIG. 206).

5a indicates an outside air inlet of the air cleaner 5.

The exhaust passages 7 of the front cylinders 1A and 1B open downward near the down pipe 4a of the vehicle body 7 and the frame 4, as shown in Figure WJ2, and the exhaust passages 7 of the rear cylinders 1C and 1D open downward. 7 opens toward the rear as shown in FIG.

8 is an exhaust pipe, and 9 is a muffler.

The secondary air is led from the intake air distribution chamber 6 to each of the exhaust passages 6 through the secondary air control valve 10 and check valve 11, for example.

As shown in FIG. 2, the secondary air control valve 10 is disposed at the center of the lower surface of the intake distribution chamber 6, and one surface of the diaphragm 12 provided in the valve box 10a is connected to the intake passage 2 of one of the cylinders. It communicates with the pipe 16.

Afterburn is prevented by closing the secondary air passage 15 with the valve body 14 attached to the diaphragm 12 in conjunction with the negative pressure in the intake passage 2 during deceleration of the engine.

Also, the check valves 11 are arranged on both left and right sides of the lower surface of the intake air distribution chamber 6, and communicate with the secondary air control valve 10 through a branch pipe 16 (Fig. 6). As shown in Fig. 4, valve bodies 1 such as reed valves for the front and rear cylinders, respectively.
7 is arranged, and its valve body 17 opens in response to the pulsation of exhaust gas in the exhaust passage 7, allowing air to flow only from the valve box 11a to each exhaust passage 7. Reference numeral 17a indicates an opening regulating stopper for the valve body 17.

Then, secondary air is guided from the check valve 11 to the exhaust passage 7 via the pipe frame of the vehicle body, and in the case of failure, each check valve 11 and the exhaust passage 7 of the front cylinders 1A and 1B @7 is connected via the down pipe 4a114a, and the down pipe 4a is connected to 1 in the middle.
Connect the pipe 41 with both ends closed using bolts 18 & 18b etc.

The upper part of the pipe 41 and the check valve 11 are connected by a connecting pipe 19. Also, the lower part of the tube 41 is the cylinder head 20 (Figures 5 and 6).
A communication pipe 22 is connected to the ventilation hole 21 formed near the exhaust passage 7.
Connect with.

As shown in FIGS. 5-6, the ventilation hole 21 has a hole 21a that is substantially perpendicular to the exhaust passage 7, and the hole 21a branches into two parts toward a pair of exhaust valves 26, 26, and is located near the exhaust valve 26. 024, which consists of holes 21b opening into the exhaust passage Z, is a blind plug for closing the end opening of the hole 21b, and 25 is a cooling water passage of the cylinder head 20, which is an cylinder barrel omitted in Fig. 9. It communicates with the cooling water passage through the hole 25a.

In FIG. 6, 22a is a short pipe for connecting the ventilation hole 21 and the communication pipe 22, and 26 is a short pipe attachment member fixed to the short pipe 22m by welding or the like, and is attached to the cylinder head 20 with bolts 27 or the like. 28 indicates a seal ring.

In addition, from each check valve 11 to the exhaust passage 7 of the rear cylinders 1C and 1D, there is a communication pipe 29 as shown in FIG. 3 in the case of FIG. 9.
・The secondary air is guided through the main pipe 4b which passes from the side of the intake distribution chamber 5 to the vicinity of the exhaust passage 7 of the rear cylinders 1C and 1D in Fig. 1. Sometimes I do.

As described above, in the exhaust purification device of the present invention, the secondary air is guided to the exhaust passage 7 of the engine 1 via the pipe frame 4a of the vehicle body, so the number of piping such as a dedicated secondary air supply pipe can be reduced. Alternatively, it can be omitted, making it possible to construct this type of exhaust purification device compactly, and also having the effect of preventing the above-mentioned piping from spoiling the external appearance of vehicles of this type, where design is important.

[Brief explanation of the drawing]

Fig. 1 is a side view of a motorcycle equipped with an exhaust purification device for an internal combustion engine according to the present invention, and Figs. 2 and 6 are respectively Fig. 1 n-n.
-1-it line enlarged cross-sectional view, Figure 4 is a bar lv line cross-sectional view in Figure 6, @5 figure is an enlarged longitudinal cross-sectional view of a part of the cylinder head,
Figure 6 is a bottom view of the same. 0 1 is the internal combustion engine, 2 is the intake passage, 3 is the carburetor, 4 is the body frame, 4a is the down via', 5q is the air cleaner, 6
is an intake distribution chamber, and 7 is an exhaust passage. Figure 2 Figure 4 4/--・＜'

Claims (1)

[Claims] (1) A device for supplying secondary air to the exhaust passage of an internal combustion engine for a motorcycle to purify the exhaust with NaK, characterized in that the secondary air is guided to the exhaust passage through a pipe frame of the vehicle body. Exhaust purification device for internal combustion engines for motorcycles.