JPS5851396Y2 - Secondary air introduction device in the secondary air supply system of an internal combustion engine - Google Patents

Description

[Detailed description of the invention] The present invention relates to a device for introducing secondary air into the secondary air supply device in a device that supplies secondary air to the exhaust system of an internal combustion engine for the purpose of purifying harmful gases. It is something.

Recently, in internal combustion engines, secondary air is suction-supplied to the exhaust system via a check valve by utilizing exhaust characteristics such as exhaust pulsation in the exhaust pipe, or secondary air is supplied to the exhaust system using an air pump. However, when drawing this secondary air from the atmosphere and supplying it to the exhaust system, it is accompanied by a considerable amount of intake noise. An air supply pipe is connected to an air cleaner for intake into an engine, and a portion of the air in the air cleaner is introduced as secondary air into a secondary air supply device.

When introducing secondary air into the exhaust system from the intake air cleaner, the present invention provides a filter element for secondary air that is curved along the circumferential direction on the outside of the air cleaner. By introducing secondary air from almost the entire surface of the filter element, the amount of secondary air can be increased, and the filter element can be prevented from becoming clogged in extreme areas.
The purpose is to prevent contamination and damage and increase the life of the filter element.

Next, an example of the present invention will be explained with reference to the drawings. In the drawings, reference numeral 1 indicates a flat cylindrical cleaner case having a removable lid 2. A cylindrical filter element 3 is provided inside the case 1. An annular dirty passage 4 is provided between the inner surface of the outer wall plate 1 and the inner surface of the outer wall plate 1 (the figure shows a case in which the filter element 3 is offset from the center of the case 1). A nose pipe 5 for air intake is provided in the tangential direction, and the intake air entering from the nose pipe 5 flows in the annular dirty passage 4 in the circumferential direction, and then enters the clean chamber 6 in the filter element 3. Intake air is drawn into a carburetor (not shown) through a socket 7 at the center of the bottom of the case 1.

A secondary air chamber 8 communicating with the dirty passage 4 is provided on the outer surface of the outer wall plate 1 of the case 1.
A secondary air filter element 9 is placed inside, and a rubber frame 10 surrounding the outer periphery of the filter element 9 is sandwiched between the flange 8 on the outer periphery of the chamber 8 and the outer wall plate 1. A passage forming member 11 is provided on the inner surface of the outer wall plate 1 of the cleaner case 1 and extends in the circumferential direction in a state substantially parallel to the outer wall plate 1. forming an extending secondary air introduction passage 12, and communicating one end of the secondary air introduction passage 12 with the chamber 8 by sandwiching the filter element 9 at an inner circumferential portion of the secondary air filter element 9; Population section 12 at the other end
is opened to the dirty passage 4 at a position away from the nose pipe 5, and a secondary air supply pipe 15 with a check valve 14 is connected from a socket 13 serving as a secondary air supply passage 16 which communicates the inside of the chamber 8 with the dirty passage 4. When connecting the secondary air supply pipe 15 to the chamber 8, the axis of the socket 13 is aligned with the secondary air introduction passage 12. The secondary air filter element 9 is joined in a direction from one end toward the inlet 12 at the other end, and in a tangential direction to the arcuately curved secondary air filter element 9.

Note that the socket 13 may be omitted and the secondary air supply pipe 15 may be directly connected to the chamber 8.

In this configuration, the intake air that enters the dirty passage 4 on the outer periphery of the intake filter element 3 from the nose pipe 5 is
The intake air flows through the dirty passage 4 in the circumferential direction of the filter element 30 and enters the clean chamber 6 from the wide area of the filter element 3. On the other hand, a part of the intake air flowing in the circumferential direction inside the dirty passage 4 is introduced into secondary air. The air is introduced into the introduction passage 12 from the passage 120, and after passing through the secondary air filter element 9, is supplied from the chamber 8 to the exhaust system of the engine via the secondary air supply passage 16 with the check valve 14. It is.

In this case, there is an inlet section 12 in the cleaner case 1.
A secondary air introduction passage 12 opening into the dirty passage 4 is formed along the inner surface of the outer wall plate 1' of the cleaner case 1, and one end of the secondary air introduction passage 12 is sandwiched between the secondary air filter element 9. By communicating with the chamber 8, the secondary air flowing from the secondary air introduction path 12 toward the socket 13 is
The axis of the socket 13 is distributed over the entire inner circumferential surface of the filter element 9 and is connected to the chamber 8.
By configuring the direction toward the 0-input slot 12 and the tangential direction to the arcuately curved secondary air filter element 9, the secondary air sucked into the socket 13 is directed toward the filter element 9. This allows the secondary air to pass through almost the entire surface of the filter element 9, and the flow of the secondary air passing through the filter element 9 is substantially linear due to the above configuration. Since the change in direction is extremely small, the overflow resistance is not only small, but also no local clogging occurs, and moreover, the exhaust gas due to malfunction or breakage of the check valve 14 in the secondary air supply passage 16, etc. During the backflow of the backflow, the backflow exhaust gas can be widely dispersed to the secondary air filter element 9 by the tangential socket 13, so that the filter element 9 will not be locally contaminated or damaged by soot, etc. in the backflow exhaust gas. There is no such thing.

Therefore, according to the present invention, the secondary air to the engine exhaust system is
When the secondary air is introduced from the intake air cleaner through the secondary air filter element, the flow resistance of the secondary air filter element is small and the amount of secondary air can be increased. clogging,
It has the effect of increasing its lifespan without contamination or damage.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan sectional view of an intake air cleaner, FIG. 2 is an enlarged sectional view taken along ■-■ of FIG. 1, and FIG. This is a magnified canine section view. 1...Cleaner case, 3...Filter element, 5...Nose pipe, 8...
・Chamber, 12...Secondary air introduction path, 9.
...Secondary air filter element, 15...
...Secondary air supply pipe, 16...Secondary air supply passage.

Claims (1)

[Scope of utility model registration request] In an intake air cleaner including a cylindrical filter element in a cylindrical cleaner case, a chamber is provided on the outer surface of an outer wall plate forming the circumference of the cylindrical cleaner case, and a chamber is provided within the chamber. A secondary air filter element curved in an arc shape is provided along the inner periphery of the outer wall board, while a secondary air introducing filter element is provided inside the cleaner case that extends in the circumferential direction along the inner surface of the outer wall board in the cleaner case. A channel is formed by a channel forming member installed in the cleaner case, one end of the secondary air introduction channel is communicated with the chamber by sandwiching the secondary air filter element, and the inlet of the other end is connected to the chamber through the filter element for secondary air. A secondary pipe is opened in the dirty passage outside the cylindrical filter element in the case at a position remote from the opening of the nose pipe for air intake into the dirty passage, and the chamber has one end connected to the exhaust system of the engine. The air supply passage is arranged such that the axis of the secondary air supply passage is in a direction from one end to the inlet of the other end of the secondary air introduction passage, and is tangent to the arcuate curved secondary air filter element. A secondary air introduction device in a secondary air supply device for an internal combustion engine, which is joined in the same direction as the secondary air supply device.