JPS5849404Y2 - Fuel evaporative gas treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to a device for treating evaporated fuel gas generated from a float chamber of a carburetor when an engine is stopped.

With an inner vent type carburetor, a large amount of evaporated gas is generated in the float chamber when the engine is stopped, especially when the temperature is high immediately after stopping, and this flows into the intake manifold from the air vent, causing the mixture to become too rich and causing starting problems. wake up,
There is a problem called percolation.

Conventionally, in order to prevent this and to prevent air pollution caused by evaporative gas, fuel evaporative gas generated in the float chamber 1a of the carburetor 1 is guided to a canister 2 to be adsorbed, as shown in FIG. During operation, a method was used in which the gas adsorbed in the canister was sucked into the intake system and combusted using negative intake pressure.

However, in the above method, since dynamic pressure is applied to the air vent 1b during engine operation, the canister cannot be sufficiently scavenged, and its suction force deteriorates very quickly.

Furthermore, since expensive equipment such as a canister is required, the cost is also very high.

The present invention was devised in view of and to solve the problems of the conventional structure described above, and an object thereof is to provide an evaporative gas treatment device that does not require any expensive parts and has an extremely simple structure.

The present invention will be explained below based on the embodiment shown in FIG.

As shown in FIG. 2, the air cleaner 3b is installed at a location equal to or lower than the float chamber 1a, and
It is connected to the carburetor through an intake passage 4, and also communicates with the float chamber 1a via a communication passage 5.

As is well known, gasoline components are heavier than air (2 to 4 times heavier than air), so in the conventional inner vent method,
As mentioned earlier, evaporative gas passes through the air vent 1b and accumulates in the intake manifold 6, but in the structure of the present invention, the evaporative gas is not connected to the intake manifold 6 because the air cleaner 3 is located at a lower position than the float chamber 1a. The air passes through the passage 5 and accumulates in the air cleaner 3.

At this time, there is a possibility that some evaporative gas may flow out from the air vent 1b, but the amount is not large enough to cause a problem.If the communication path 5 is installed lower than the highest position of the air vent 1b as shown in the figure, it will be possible to escape from the air pant. outflow will be almost eliminated.

Next, when the engine is started, the evaporated gas accumulated in the air cleaner 3 is sucked together with fresh air into a cylinder (not shown) of the engine body 7 via the intake passage 4, the carburetor 1, and the intake manifold 6, and is combusted.

During this process, the intake of evaporative gas into the cylinder is slower than that of evaporative gas that accumulates in the intake manifold as in conventional systems, so the air-fuel mixture does not become too rich and the engine starts smoothly. I can do it.

In fact, compared to the system shown in FIG. 1, the structure is extremely simple, and since it does not require any accessory devices such as a canister, the cost is also extremely low.

Furthermore, since the evaporated gas is stored in the air cleaner, it goes without saying that it does not directly flow outside and pollute the atmosphere.

As described above, the evaporative gas treatment device of the present invention has a simple configuration in which the air cleaner is installed at the same level as or lower than the float chamber of the vaporizer, and the float chamber and the air cleaner are communicated, thereby solving the problems of the conventional method. It can solve all the points, and its effectiveness and usefulness are extremely excellent.

Particularly in cab-over type automobiles, it is difficult to place an air cleaner above the engine, but this invention is very effective because it is easy to secure a suitable location at a location equal to or lower than the float chamber. .

It is advantageous if the air suction tube 3a of the air cleaner 3 is arranged as shown by the dashed line in FIG. 2 because the gas reservoir capacity of the air cleaner can be increased.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a conventional device using a canister.
FIG. 2 is a block diagram showing an embodiment of the present invention. 1... Carburetor, 1a... Float chamber, 3... Air cleaner, 5... Communication passage, 7... Engine body.

Claims (1)

[Scope of utility model registration request] 1. A fuel evaporative gas treatment device, characterized in that an engine air cleaner is installed at a location equal to or lower than a float chamber of a carburetor, and the float chamber and the air cleaner are communicated with each other.