JPS6345534Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a secondary air supply system for an internal combustion engine, and in particular improves the means for attaching a one-way valve and a silencer to an engine air cleaner.

(Prior technology) A passage with an open end in the exhaust system is connected to an air cleaner via a one-way valve, and the one-way valve is opened and closed using the pressure pulsation of the exhaust, and the negative pressure of the exhaust pulsation is used to drain the atmosphere. Devices for introducing the gas into the exhaust system are already well known (see, for example, Japanese Utility Model Publication No. 45224/1983 and Japanese Utility Model Application No. 23618/1989).

By the way, the one-way valve, silencer, or air filter in these secondary air supply devices,
They were placed in the middle of the secondary air piping or on the outside side or bottom of the air cleaner housing (casing).

(Problem to be solved by the invention) However, in the former case, it is necessary to install a bracket for holding the silencer of the one-way valve on the engine body, etc. The disadvantages were that the piping was long, the layout of the engine room was complicated, and the engine was not easy to assemble or maintain.

Furthermore, in the latter case, the external size of the air cleaner becomes larger, and the center of gravity of the air cleaner moves to the peripheral wall of the air cleaner, making it easier for cracks to occur in the peripheral wall due to vibration.

The present invention aims to solve such problems.

(Means for Solving the Problems) Therefore, the present invention provides a device that communicates an engine air cleaner and an exhaust system through a one-way valve that opens and closes in response to pressure pulsations in the exhaust gas, and introduces secondary air into the exhaust system. A silencer is installed on the back surface of the lid of the engine air cleaner so as to communicate with the clean side of the engine air cleaner, and the one-way valve is also provided on the lid, located externally downstream of the silencer, and the silencer The opening to the clean side is formed above the bottom of the silencer.

(Function) Therefore, by doing this, the piping can be simplified and the layout in the engine room can be neatly organized, and the silencer can be mounted on the lid and the one-way valve can be mounted on the outside of the lid. Therefore, maintenance and inspection can be easily carried out by removing the lid, which greatly improves maintainability.Since the silencer opens on the clean side of the air cleaner, noise from the exhaust system and the one-way valve are reduced. Opening/closing noise is less likely to be transmitted to the outside,
The air cleaner itself has a good balance with its center of gravity in the center, and does not resonate with engine vibrations and vibrate violently.

(Example) Examples of the present invention will be described below based on the drawings.

In FIG. 1, 1 is an engine body, 2 is an exhaust manifold, 3 is an intake manifold, and 4 is an engine air cleaner body.

5 is an introduction passage for supplying secondary air to the exhaust system, and is connected to a reed valve 6, which is a one-way valve attached to the air cleaner body 4.

As shown in FIG. 2, the reed valve 6 includes a circular or square reed valve base 7, a soundproofing member 8 embedded in the reed valve base 7, and is also fixed to the reed valve base 7 with screws 9. The reed valve 6 is composed of a reed valve (valve body) 10 and a stopper 11, and the reed valve 6 has a reed valve base attached to the inner circumferential wall of a casing 13, which is fixed to the top surface of the lid portion 4a of the air cleaner body 4 at the approximate center with screws 12 or the like. It can be attached by press-fitting 7.

The air cleaner lid 4a is configured to be detachable from the air cleaner main body 4 with a clamp 21, and has an opening 14 in its center so as to communicate with the inside of the casing 13.

Note that one end of the introduction passage 5 is connected to the side surface of the casing 13 so as to open toward the inside. Further, reference numeral 22 in the figure indicates a lid portion 4a and a reed valve base 7 so as to surround the opening portion 14.
This is a sealing member interposed between the reed valve base 7 and the reed valve base 7, and has the function of improving sealing performance and preventing vibrations from being transmitted from the lid portion 4a to the reed valve base 7 side.

A silencer 17 that is substantially concentric with the air cleaner main body 4 and defines an air chamber on the clean side, which is inside the air cleaner element 16, is fixed to the inner wall, that is, the back surface of the lid portion 4a.

The silencer 17 has a plurality of small holes 24 formed in its circumferential wall at a position higher than the bottom thereof, and communicates the reed valve 6 with the air cleaner clean side through the small holes 24, thereby allowing air to flow from the intake manifold 3 and the carburetor. The evaporated fuel, blow-by gas, etc. are applied to the outside bottom of the silencer 17 and dispersed, reducing the amount that enters the inside of the silencer 17 and preventing it from adhering to the reed valve 6.

The opening may have various shapes such as a small hole or an annular slit.

In this way, according to the present invention, the air on the clean side of the air cleaner body 4 is supplied to the exhaust system via the reed valve 6, so a filter for the reed valve 6 is no longer necessary; Even if there is exhaust gas flowing backwards,
Since it is discharged to the clean side, it will be sucked into the engine again and will not pollute the atmosphere.

On the other hand, in engine assembly work, etc.
Since the lid part 4a can be freely rotated with respect to the air cleaner body 4, the introduction passage 5 can be adjusted depending on the mounting position of the exhaust manifold 2 on the engine body 1.
can be connected without being subject to directional restrictions as in the past, and the degree of freedom in the layout of piping within the engine room is significantly improved.

Furthermore, since the reed valve 6 and the silencer 17 are located at the center of gravity in the center of the air cleaner body 4, the weight balance is good.
Combined with increased rigidity due to the installation of silencer 17, etc., durability against engine vibration has improved,
It is possible to reliably avoid cracks in the outer circumferential wall that conventionally occur when a reed valve is attached to the outer circumference of an air cleaner.

In order to deal with the exhaust noise transmitted through the reed valve 6 and the banging noise caused by the opening and closing of the reed valve 6, multiple soundproof walls such as the silencer 17, element 16, and air cleaner body 4 are installed as the air cleaner is opened on the clean side. It has a very high soundproofing effect.

Moreover, since there is plenty of space inside the clean side, the shape of the silencer 17 is not limited to the illustrated example, but the volume and shape can be freely selected, and therefore, the silencer 17 can be freely selected depending on the purpose from low frequencies to high frequencies. Can be muted.

Further, since the silencer 17 and the one-way valve 6 are provided on the lid portion 4a which is detachable from the air cleaner main body 4, maintenance work such as cleaning and inspection can be easily performed. Since it is located on the upper surface of the lid part 4a, it is possible to inspect the lid part 4a without removing it from the air cleaner main body 4, and maintainability is very good.

(Effects of the invention) As explained above, according to the invention, a silencer is installed on the back side of the lid of the engine air cleaner so as to communicate with the clean side of the air cleaner, and the silencer is located externally downstream of the silencer. Similarly, the one-way valve is provided in the lid, and the silencer is formed such that the opening to the clean side is located above the bottom of the silencer.As a result, piping is simplified and the engine The layout of the room is neat and clean, and since the silencer is installed on the back of the lid, maintenance and inspection can be easily performed by removing the lid. Since the silencer is located on the clean side of the air cleaner, maintenance and inspection are easy without the need to remove the lid, which greatly improves maintainability.The silencer opens on the clean side of the air cleaner, reducing transmitted noise from the exhaust system and the opening/closing sound of one-way valves. At the same time, since the opening of the silencer is located above the bottom of the silencer, backflow exhaust through the reed valve and blowby gas that flows backflow from the intake system are bypassed and are prevented from passing through directly. At the same time, the air cleaner itself is well-balanced with its center of gravity in the center, and does not vibrate violently in resonance with engine vibrations.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing a first embodiment of the present invention, and FIG. 2 is a sectional view of the air cleaner. 2... Exhaust manifold, 4... Engine air cleaner body, 4a... Lid, 5... Secondary air introduction passage, 6... Reed valve, 13... Casing, 14
...opening, 16...element, 17...silencer, 24...small hole.

Claims (1)

[Scope of utility model registration request] In a device that communicates an engine air cleaner with an exhaust system through a one-way valve that opens and closes in response to pressure pulsations of exhaust gas, and introduces secondary air into the exhaust system, the engine air cleaner is configured to have a communication opening on a clean side of the engine air cleaner. A silencer is installed on the back side of the lid of the air cleaner, and the one-way valve is located externally downstream of the silencer and also on the lid, and the silencer has an opening to the clean side located above the bottom of the silencer. A secondary air supply device characterized in that it is located at and formed at.