JPS5999022A - Exhaust gas purifying apparatus for internal-combustion engine - Google Patents

Abstract

PURPOSE:To make an exhaust-gas purifying apparatus in a compact structure and to facilitate installation of the same, by arranging secondary-air feed pipes for feeding secondary air to each cylinder of a V-type multi-cylinder internal combustion engine at particular positions of the engine, and disposing check valves in a common valve box which is disposed between the cylinders. CONSTITUTION:Two cylinders 1A, 1B of an internal combustion engine 1 are arranged in a V-shape along the length of the vehicle body, and a check valve 4 permitting air to flow only toward an exhaust passage 2 is disposed in each of secondary-air feed pipes 3 which are communicated with respective exhaust passages 2. Here, the pipes 3 are disposed respectively around the cylinders 1A, 1B such that they are located on the opposite side of a chamber 51 in which a cam chain 5 for driving an intake valve and an exhaust valve is disposed. Further, the other ends 3b of said pipes 3 are communicated with the inside of a common valve box 41 via respective check valves 4, and the valve box 41 is disposed between the two cylinders 1A and 1B. By employing such an arrangement, it is enabled to shorten the length of the pipes 3 are to reduce the number of valve boxes 41. Therefore, the structure of an exhaust-gas purifying apparatus can be simplified.

Description

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

This type of purifier generally communicates a secondary air supply pipe with the exhaust passage of the engine, and the secondary air supply pipe is provided with a check valve that allows air to flow only toward the exhaust passage. By introducing secondary air into the exhaust passage from the secondary air supply pipe using fluctuations in the exhaust pressure in the exhaust passage, air pollutants such as unburned gas in the exhaust gas are reduced.

It is an object of the present invention to arrange this type of exhaust gas purification device in a V-multiple cylinder internal combustion engine with a simple and compact structure.

That is, a secondary air supply pipe 6 is connected to the exhaust passage 2 of the internal combustion engine 1, and the secondary air supply pipe 6 is provided with a check valve 4 that allows air to flow only toward the exhaust passage 2. In the purification device, the secondary air supply pipe 6 for each cylinder of the V-type multi-cylinder internal combustion engine 1 is arranged on the side opposite to the accommodation capacity 51 of the cam chain 5 for operating the intake and exhaust valves of each cylinder, and the plurality of The check valves 4 of the secondary air supply pipes 6 are provided in a common valve box 41, and the valve box 41 is arranged between the cylinders forming the V-shape.

1 to 4 show an example in which the present invention is applied to a motorcycle equipped with an air-cooled OHC (overhead camshaft) type V-type two-cylinder internal combustion engine 1.

As shown in Fig. 1, the two cylinders IA and IB of the engine 10 are arranged in a square shape at the front and rear of the vehicle body, and the intake passages 6 and 6 open inwardly, and the exhaust passages 2 and 2 open outwards. and open it. 7 is the exhaust pipe, 71 is the muffler, 8 is the carburetor, 9 is the air cleaner, and 10 is the intake air distribution! , 10a is a communication hole with the carburetor 8, 11 is a frame of the vehicle body 7, and 12 is a fuel tank.

Secondary air supply pipes 6 and 6 for the above cylinders 1A and 1B
As shown in FIG. 2, the cylinder barrel 16 and the cylinder barrel 14 are arranged around the cylinders 1A and 1B on the side opposite to the storage chamber 51 of the cam chain 5 for operating the intake and exhaust valves. It is fixed between protrusions 13b and 14b formed on each of the cooling fins 13a and 14a.

One end 6a, 6a of each of the secondary air supply pipes 6, 6 communicates with a passage 15 formed below the exhaust passage 2, and 016 is fixed to the end 6a, 6a of each supply pipe 3-3 by bath welding or the like. Install the bolts 16 to the cylinder head 14 using the supply pipe mounting bracket.
Attach with a etc. The passage 15 has two exhaust pipes yP17 and
17, and opens into the exhaust passage 2 near the exhaust valve 17.

The other ends 6b, 6b of the primary mixing secondary air supply pipes 6, 6 are communicated into a common valve box 41 via a check valve 4 such as a reed valve. The check valve 4 opens in response to the pulsation of exhaust gas in the exhaust passage 2, allowing air to flow only from the inside of the valve box 41 to each of the supply pipes 6. 4a indicates an opening regulating stopper of the check valve 4.

The valve box 41 is arranged at the threshold of both cylinders 1A and 1B forming a V-shape, and is fixed to, for example, the side surface of the cylinder barrel 16 or the upper surface of the crankcase 28 with bolts 18 or the like. and valve box 4
1 and the air intake/distribution chamber 10 of the air cleaner 9 are connected through a pipe 19.
A, 19b, etc. are used for communication (Fig. 6).

For example, a secondary air control valve 2o is provided between the valve box 41 and the intake air distribution chamber 10 to prevent afterburn by closing the secondary air passage during deceleration. In the case of the figure, one side of the diaphragm 22 provided in the valve box 21 of the control valve 20 is connected to one of the cylinders 1
A valve body 24 is connected to the intake passage 7 of B through a pipe 26 and is attached to the diaphragm 22 in conjunction with the negative pressure in the intake passage Z.
By retracting against the spring 25, the valve body 21
It is configured to close the secondary air passage 26 inside.

In this case, the control valve 20 also has a V-shaped cylinder 1801B.
Place it in between and fix it to engine 1 with a bracket or the like.

Figures 5 and 6 show an embodiment applied to a water-cooled OHC V-type four-cylinder internal combustion engine.

That is, the front and rear cylinders 1A and 1B forming a V-shape are arranged in a vertical position, and the left and right cylinders 1A and IA, IB and 1 form a pair.
A storage chamber 51 for the cam chain 5 is provided between B. The secondary air supply pipes 6 for each of the cylinders 1A and 1B are arranged on the opposite side of the trough cylinder from the storage chamber 51.

Also, the valve box 41 of the check valve 4 is connected to the front and rear cylinders 1A and 1 forming a vm.
Place one on the left and right in the wide space on the side between B.
Each valve box 41 is provided with a check valve 4 for the front and rear cylinders 1801B. However, one common valve box 41 may be arranged for the four cylinders, and the four check valves 4 may be provided in that valve box 41.

Each of the valve boxes 41 is fixed to the upper surface of the crankcase 28 or to an elbow 60 of the cooling water pipe 29 with a bracket 61, bolt 62, etc., as shown in FIG. 6, for example. Further, the two valve boxes 41 and the secondary air control valve 20 communicate with each other through a branch pipe 19c.

For example, as shown in FIG. Fix with bracket 27 etc.

Note that the other configurations are the same as those in the examples shown in FIGS. 1 to 4 above.

As described above, the exhaust purification device of the present invention arranges the secondary air supply pipe 6 for each cylinder of the V-type multi-cylinder internal combustion engine 1 on the opposite side from the housing chamber 51 of the cam chain 5 for operating the intake and exhaust valves of each cylinder, This is because the check valves 4 of the plurality of secondary air supply pipes 6 are provided in a common valve box 41.

The secondary air supply pipe 6 can be shortened, and the number of valve boxes 41 can be reduced to make the structure of this type of exhaust gas purification device more compact. In addition, since the valve box 41 is arranged using the open space between the V-shaped cylinders, it can be configured without considering interference with other equipment, which is advantageous in terms of design and assembly. It has the effect of

[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, FIG. 2 is a partially cutaway plan view of the internal combustion engine, and FIG. 6 is an enlarged view taken along the line 1-1 in FIG. FIG. 4(a) is an enlarged sectional view of the second vJIV-bar line, FIG. 4(b) is a side view thereof, FIG. 5 is a plan view of an internal combustion engine of another embodiment, and FIG. It is a bamboo-V1 line view. 1 is an internal combustion engine, 2 is an exhaust passage, 6 is a secondary air supply pipe, 4
41 is a check valve, 41 is a valve box, 5 is a cam chain, and 51 is its accommodation layer.

Claims (1)

[Claims] (1) In an exhaust gas purification device, a secondary air supply pipe is connected to the exhaust passage of an internal combustion engine, and the secondary air supply pipe is provided with a check valve that allows air to flow only toward the exhaust passage. ,
The secondary air supply pipes for each cylinder of a V-multiple cylinder internal combustion engine are arranged on the side opposite to the capacity of the cam chain for operating the cylinder's intake and exhaust valves, and the check valves of the plurality of secondary air supply pipes are common. An exhaust gas purification device for an internal combustion engine, which is installed in a valve box of an internal combustion engine and arranged between the V-shaped cylinders of the valve box.