JPS6250657B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a multiple carburetor in which a plurality of vaporizers are arranged in parallel. The present invention relates to a fuel vapor processing device that is installed in a canister and prevents fuel vapor from being released into the atmosphere.

Conventionally, such an evaporative fuel processing device has been constructed by extending evaporative fuel passages from the float chambers of a plurality of vaporizers, and connecting these passages to a canister containing an evaporative fuel adsorbent via a convergence passage equipped with a solenoid valve. It is known that when the engine is stopped, the electromagnetic valve is opened, and the evaporated fuel generated in each float chamber is introduced into the canister and adsorbed. However, the solenoid valve is 1
The fuel passage between each float chamber and the solenoid valve is relatively long, so when the engine is running or the vehicle is turning, the oil level in the float chamber can be tilted significantly. When the opening of the evaporative fuel passage to the float chamber is submerged below the oil level, fuel flows from the float chamber into the fuel passage and accumulates, and the next time the solenoid valve is opened, the fuel flows into the canister. However, it has the disadvantage that it saturates the adsorption function of the internal vaporized fuel adsorbent.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an effective device that can eliminate the above-mentioned drawbacks while requiring only one solenoid valve as in the conventional device.

In order to achieve the above object, the present invention provides a multiple carburetor in which a plurality of carburetors are arranged in parallel, in which the spaces above the oil level of the float chambers of the adjacent carburetors are communicated with each other via a communication pipe. Then, the starting end of the vaporized fuel passage connected to the canister containing the vaporized fuel adsorbent is opened in the space above the oil level of the float chamber of any one of these vaporizers, and the engine is inserted into the starting end opening. A solenoid valve is provided that opens when the valve is stopped and closes when the float is in operation, and the communicating pipe has an end that projects from the inner surface of the float chamber in a substantially horizontal direction, and the projecting length of each part of the projecting end is set downward. It is characterized by getting longer as it goes.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Vaporizer C ₁ , C ₂
and one auxiliary carburetor _C3 placed between them.
The main carburetors C ₁ , C ₂ are connected to intake ducts 1 ₁ , 1 that generate lean mixtures to be supplied to the combustion chambers of the respective engines.
₂ , and the auxiliary carburetor _C3 has an intake passage ₁₃ that produces a rich mixture in each auxiliary combustion chamber of the engine.

In addition, the above-mentioned carburetors C ₁ , C ₂ , C ₃ are connected to each intake path 1.
Each of the float chambers _{2 1 ,} 2 2 , 2 ₃ has a bottom formed below the float chambers 2 ₁ , _{2 2} , _{2 3 ,} each having a corresponding intake passage 1 _{1 .} , 1 ₂ , 1 ₃ through fuel nozzles (not shown), a specified amount of fuel F is always stored.

First main carburetor C ₁ and sub carburetor ₃ adjacent to each other
and between the auxiliary carburetor _C3 and the second main carburetor _C2 , there is a space between the oil level space _a1 of the float chamber ₂₁ and the oil level space _a3 of the float chamber ₂₃ . A communicating pipe 3 and a communicating pipe 4 communicating between the above-oil level space a ₃ of the float chamber 2 ₃ and the above-oil level space a ₂ of the float chamber 2 ₂ are respectively installed horizontally.

Ends 3a and 4a of the communication pipes 3 and 4 on the first and second main carburetor C ₁ and C ₂ sides project horizontally from the inner wall surface of the float chambers 2 ₁ and 2 ₂ , and these projecting ends The protruding length of each part of 3a and 4a becomes longer as it goes downward.

1st and 2nd main carburetor C ₁ , C ₂ float chamber 2
The spaces a ₁ , _{a 2 above} the oil surface of the oil surfaces 1 and _{2 2} are communicated with each other by a ventilation passage 5 ₁ , and this ventilation passage 5 ₁ is further connected to the multiple vaporizer through a ventilation passage 5 ₂ extending from the intermediate portion thereof. A normally closed electric valve 7 is provided in the middle of the air passage ₅₂ and communicated with the air cleaner 6 . A solenoid 8 of the electromagnetic valve 7 is connected to a battery B via an ignition switch S of the engine. In addition, the communication pipes 3 and 4
If the ventilation resistance is so small that it does not pose a problem in terms of the performance of each vaporizer, the ventilation passage 5 ₁ can be connected only to one of the float chambers 2 ₁ or 2 ₂ .

One vaporizer among all the vaporizers, that is, the second main vaporizer _C2 in the illustrated example, is connected to an evaporated fuel passage 10 such that its starting end opens to the space _a2 above the oil level of the float chamber ₂₂ . A canister 11 is connected to the end of this passage. The canister 11 is a well-known type that stores a fuel vapor adsorbent such as activated carbon inside, and when air containing fuel vapor passes through the canister 11, it adsorbs the fuel vapor and releases the fuel vapor into the atmosphere. This is to prevent

A normally open electromagnetic valve 14 having a valve 13 biased in the valve opening direction by a spring ₁₂ is provided at a starting end opening 10a of the evaporative fuel passage 10 into the float chamber 22. The solenoid 15 of this electromagnetic valve 14 is also connected to the battery B via the ignition switch S.

Incidentally, Ig in the figure is an ignition circuit of the engine that is activated when the ignition switch S is closed.

Next, to explain the operation of this embodiment, when the ignition switch S is opened to stop the engine operation as shown in the figure, the solenoids 8 and 15 of both the electromagnetic valves 7 and 14 are demagnetized, so they are always demagnetized. The closed type solenoid valve 7 blocks the ventilation path ₅₂ , and the normally open type solenoid valve 14
The spring 12 holds the valve 13 in the open position to open the starting end opening 10a of the vaporized fuel passage 10. Therefore, the float chamber 2 of each vaporizer
When vaporized fuel is generated in ₁ , 2 ₂ , 2 ₃ , the vaporized fuel passes through the communication pipes 3 and 4 to the float chamber 2 ₁ of the first main carburetor C ₁ and the float chamber ₂ of the sub-vaporizer C 3 .
_3. The fuel flows sequentially to the float chamber ₂₂ of the second main vaporizer _C2 , and then enters the canister 11 via the vaporized fuel passage 10, where it is adsorbed.

Next, if the ignition switch S is closed and the engine is started, each solenoid 8 of both electromagnetic valves 7, 14,
15 is excited, the normally closed solenoid valve 7 conducts the air passage ₅₁ , and the normally open solenoid valve 14 conducts the spring 1.
actuate the valve 13 to the closed position against the force of 2;
The starting end opening 10a of the vaporized fuel passage 10 is closed. Therefore, the air cleaner 6, the ventilation path ₅₂ ,
Since atmospheric pressure is introduced into all float chambers 2 ₁ , 2 ₂ , 2 3 through 5 ₁ and communication pipes 3 and ₄ , each intake passage 1 ₁ , 1 ₂ , 1 ₃ is provided by a fuel nozzle (not shown).
The injection of fuel to the engine is carried out without any problem.

During operation of such an engine, canister 11
The intake negative pressure of the engine is applied through an evaporated fuel recovery passage (not shown), and the adsorbed fuel is recovered and supplied to the engine. At this time, the intake negative pressure is also transmitted to the evaporated fuel passage 10, but is prevented from being transmitted to the float chamber ₂₂ by the solenoid valve 14 in the closed state. Further, even if the oil level in the float chamber ₂₂ is greatly inclined due to turning of the vehicle or the like and the starting end opening 10a of the evaporated fuel passage 10 is submerged below the oil level, the opening 10a is Solenoid valve 14
Therefore, the fuel F in the float chamber ₂₂ does not leak into the evaporative fuel passage 10.

As described above, according to the present invention, a plurality of vaporizers
In a multiple vaporizer formed by arranging C ₁ to _{C 3} in parallel,
The spaces a ₁ to a 3 above the oil level of the float chambers 2 1 to 2 ₃ of the adjacent vaporizers C ₁ to _{C 3} are connected to communication pipes ₃ and ₄ , respectively.
are connected to the canister _{11 containing the evaporated fuel adsorbent to the oil level space a2 of the float chamber 22 of} any one of the carburetors _C1 to _C3 . The starting end of the evaporated fuel passage 10 is opened, and a solenoid valve 14 is provided at the starting end opening 10a, which opens when the engine is stopped and closes when the engine is running.
, only one solenoid valve 14 is needed to process the evaporated fuel, and when the engine is running,
Even if the oil level in the float chamber ₂₂ is greatly inclined and the starting end opening 10a is submerged below the oil level, the electromagnetic valve 14 ensures that the fuel flows out into the evaporated fuel passage 10. can be prevented.

Further, the communication pipes 3 and 4 are connected to the float chambers 2 ₁ and 2 _{2 .}
The float chamber 2 has end portions 3a, 4a projecting from the inner surface in a substantially horizontal direction, and the projecting length of each portion of the projecting end portions 3a, 4a increases as it goes downward.
₁ , 2 The oil level in ₂ is the open end 3a of the communication pipe 3, 4,
The angle of inclination of the oil level becomes large until it reaches 4a, and therefore, even when the oil level fluctuates violently, fuel does not flow in and out between adjacent float chambers, and therefore each float chamber 2 ₁ to _{2 3} It is possible to maintain normal operating conditions of each of the carburetors C ₁ to _{C 3} by always keeping the oil level inside at a specified level. Moreover, the shapes of the protruding ends 3a, 4a of the communicating pipes 3, 4 are different from each other.
4 can be easily obtained by simply cutting diagonally with respect to its axis, it is easy to process and contributes to cost reduction, and by adopting this shape,
The amount of protrusion of the communication pipes 3 and 4 into the float chambers a ₁ and a ₂ can be kept to the necessary minimum.

[Brief explanation of the drawing]

The drawing is a cross-sectional front view of a multiple carburetor showing one embodiment of the present invention. 2 ₁ to 2 ₃ ... Float chamber, 3 ... Communication pipe, 3
a...Protruding end, 4...Communication pipe, 4a...Protruding end, 10...Evaporative fuel passage, 10a...Starting end opening, 11...Canister, 14...Solenoid valve, _a1 ~
a ₃ ... Space above the oil surface, C ₁ , C ₂ ... First and second main carburetors, C ₃ ... Sub-carburetor, S ... Ignition switch.

Claims (1)

[Claims] 1. In a multiple vaporizer formed by arranging a plurality of vaporizers C ₁ to _{C 3} in parallel, each of the adjacent vaporizers
Space above the oil level in float chambers 2 ₁ to 2 ₃ of C ₁ to C ₃ a ₁
~ a ₃ are communicated with each other via communication pipes 3 and 4, and evaporation is carried out in the space a ₂ above the oil level of the float chamber _{2 2} of any one of the vaporizers C ₁ to C ₃ . Evaporated fuel passage 1 connected to canister 11 containing fuel adsorbent
0 is opened, and the starting end opening 10a is opened.
A solenoid valve 14 is provided which opens when the engine is stopped and closes when the engine is running, and the communicating pipes 3 and 4 have end portions 3a and 4a that protrude from the inner surfaces of the float chambers ₂₁ and ₂₂ in a substantially horizontal direction. and its protruding ends 3a, 4
a The protrusion length of each part was increased as it went downwards,
Evaporated fuel processing device in multiple carburetors.