JPS6338350Y2 - - Google Patents

Description

[Detailed description of the invention] This invention consists of a plurality of main carburetors that supply a lean mixture to the combustion chamber of the engine and a sub-carburetor that supplies a rich mixture to the sub-combustion chamber of the engine. This invention relates to improvements in so-called multiple carburetors for torch-ignited multi-cylinder engines.

As is well known, in such a multiple carburetor, an air vent is formed to adjust the pressure in the space above the fuel oil level in the float chamber. However, when the engine is running, if the carburetor is at a relatively high temperature and a relatively large amount of fresh fuel is supplied into the float chamber, for example, if the engine is started immediately after stopping, the low The boiling point component boils rapidly, and fuel bubbles generated as a result of this boiling cover the air vent, which may prevent the air vent from functioning as described above. Therefore, the mixture ratio of the fuel and air mixture supplied to the engine from the carburetor may change undesirably, which may adversely affect the operating condition of the engine.

Therefore, each vaporizer of the multiple vaporizer is communicated via a communication pipe, and each communication pipe is connected to an air cleaner.
For example, in Japanese Patent Laid-Open No. 56-1973, a technology was developed in which a solenoid valve that opens only when the engine is running is placed between the above-mentioned communication pipe and the air cleaner.
-Proposed in Publication No. 148651. According to this, it is possible to prevent troubles when the air vent is disabled. However, since this prior art communication pipe simply opens into the float chamber of each carburetor, vibrations of the vehicle cause fuel to move from the float chamber of one carburetor to the float chamber of the other carburetor, causing the oil level to rise. This may cause disturbances and prevent a predetermined oil level from being secured, and the fuel suction performance and operability of the carburetor main nozzle may be disrupted, causing problems even if the pressure in the space above the oil level is adjusted accurately.

Therefore, an object of the present invention is to provide a multiple carburetor that can prevent the above-mentioned problems as much as possible with a simple configuration, and thus improve engine operating performance. It is.

An embodiment of the present invention will be described below with reference to the drawings. The illustrated multiple carburetor for a torch-ignited multi-cylinder engine has two parallel main carburetors, that is, left and right first and second main carburetors _C1. , C ₂ and one auxiliary carburetor C ₃ placed between them.
The first and second main carburetors C ₁ ,
C ₂ has intake passages 1 ₁ , 1 ₂ that produce a lean mixture to be supplied to each combustion chamber of the corresponding engine, and the auxiliary carburetor C ₃ has intake passages 1 1 , 1 2 that produce a rich mixture that is supplied to each auxiliary combustion chamber of the engine. Road 1 has ₃ .

In addition, the above-mentioned carburetors C ₁ , C ₂ , C ₃ are connected to each intake path 1.
_The float chambers _{2 1 ,} 2 ₂ , 2 ₃ each have a _bottom formed below the float chambers 2 ₁ , 2 ₂ , 2 _{3 .} 1 ₂ ,
A specified amount of fuel F is always stored in the fuel nozzle (not shown) in the fuel _nozzle (not shown).
Air vents 3 1 and 3 2 are formed in the float chambers 2 ₁ and 2 _{2 of} C ₁ and C ₂ so as to face the spaces _{a 1} and a ₂ above the fuel oil level, respectively.

The above is an example of a multiple carburetor for a torch ignition type multi-cylinder engine, and the present invention is an improvement on such a device as follows. That is, there is a space above the oil level of the float chamber 2 1 between the first main carburetor C ₁ and the sub carburetor C ₃ which are adjacent to each other, and between the sub carburetor C ₃ and the _second main carburetor C ₂ . A communication pipe 4 that communicates between A ₁ and the space above the oil level A ₁ of the float chamber _{2 3 and} the space above the oil level A ₃ of the float chamber 2 3, as well as the space above the oil level A ₃ of the float chamber 2 ₃ and the float. Communication pipes 5 communicating between the chambers 2 ₂ and the oil level space a ₂ are installed horizontally.

The present invention is particularly suitable for the first and second communication pipes 4 and 5.
The ends 4a and 5a on the main carburetor C ₁ and C ₂ side project horizontally from the inner wall surfaces of the float chambers 2 ₁ and 2 ₂ , and the projecting length of each part of these projecting ends 4 a and 5 a is downward. It gets longer as you go.

According to such a configuration, when the engine is started immediately after stopping, the fuel in the float chamber rapidly boils, and the fuel bubbles generated as a result of this boiling are absorbed into any one of the multiple carburetors. Even if the air vent of the carburetor is blocked, for example, the main carburetor
Even if the air vent ₃₁ of _C1 is blocked, the inside of the float chamber fuel oil level space _a1 of _C1 of the main carburetor is the communication pipe 4, the float chamber fuel oil level space _a3 of the auxiliary carburetor _C3 ,
It is communicated with the atmosphere through the communication pipe 5 and the air vent ₃₂ of the main vaporizer _C2 , and atmospheric pressure is normally applied thereto.

Therefore, the intake path from the fuel nozzle (not shown) ₁
The injection of fuel to the engine is carried out without any problem. Similarly, even if the air vent ₃₂ of the other main carburetor _C2 is blocked by bubbles of boiling fuel, the atmospheric pressure will normally act on the _space above the fuel oil level, and the fuel will not flow. Fuel is injected from the nozzle into the intake passage ₁₂ without any problem.

Furthermore, air vents 3 ₁ of both carburetors C ₁ and C ₂ ,
Even if 3 ₂ is blocked by vaporized fuel bubbles,
Since the above-mentioned spaces a ₁ , a ₂ , and a ₃ communicate with each other and substantially share the space above the fuel oil surface, the space above the fuel oil surface a ₁ , a ₂ , and a ₃ is smaller than when they are independent. Since the volume is large, pressure changes are buffered as much as possible, and accordingly, the pressure in the space above the fuel oil level is adjusted as normally as possible.

In particular, the first and second main carburetors C ₁ of the communication pipes 4 and 5,
Each end 4a, 5a on the _C2 side projects horizontally from the inner wall surface of the float chambers ₂₁ , ₂₂ , and the projecting length of each part of these projecting ends 4a, 5a increases as it goes downward. Therefore, due to the vibrations of the automobile, the fuel in the float chambers 2 ₁ and 2 ₂ of each carburetor C ₁ and C ₂ fluctuates greatly, and the fuel flows from one float chamber 2 ₁ to the other float chamber 2 through the communication pipes 4 and 5. ₂ , or vice versa, the protrusion of the lower portions of the respective projecting ends 4a, 5a prevents the fuel from flowing into the communication pipes 4, 5. Movement from one float chamber to another is prevented as much as possible. Therefore, float chamber 2 ₁ ,
The specified oil level of 2 ₂ is maintained, and together with the normal pressure adjustment when the air vent is disabled, a good flow of fuel from the fuel nozzle is ensured.

As described in detail above, the present invention has a plurality of main carburetors that supply a lean mixture to the combustion chamber of the engine, and a sub-carburetor that supplies a rich mixture to the auxiliary combustion chamber of the engine, which are arranged in parallel. Each of the main carburetors is a multiple carburetor in which an air vent is formed to adjust the pressure in the space above the fuel oil level in each float chamber of these carburetors, and each of the above-mentioned main carburetors of the adjacent carburetors The space above the fuel oil level is communicated with each other via a communication pipe, and the ends 4a and 5a of the communication pipes 4 and 5 on the main carburetor C ₁ and C ₂ sides are connected to each other from the inner wall surface of the float chambers 2 ₁ and 2 ₂ . The protruding ends 4a and 5a protrude horizontally, and the protruding length of each part of these protruding ends 4a and 5a increases as they go downward, so that the fuel oil level in the float chamber of each carburetor can be adjusted to a predetermined value. without interfering with the ability of the fuel to be sucked out from the fuel nozzle.
Even if the air vent of any one of the multiple carburetors is blocked by bubbles from the boiling fuel, the float indoor fuel will flow through the air vent of the other carburetor. The pressure in the space above the oil level is regulated.

Therefore, fuel can be injected from the fuel nozzle of each carburetor that makes up the multiple carburetor into the intake passage without any hindrance, and a mixture with the desired fuel and air mixture ratio can be supplied to the engine. This can improve driving performance.

[Brief explanation of the drawing]

The accompanying drawing is a longitudinal sectional front view showing an embodiment of the present invention. 1 ₁ - 1 ₂ ... Intake path, 2 ₁ - 2 ₂ ... Float chamber, 3 ₁ , 3 ₂ ... Air vent, 4, 5 ... Communication pipe, C ₁ , C ₂ ... Main carburetor, C ₃ ...Sub-vaporizer, a ₁
~a ₃ ... Space above the fuel oil surface.

Claims (1)

[Scope of utility model registration request] A plurality of main carburetors C ₁ and C ₂ that supply a lean mixture to the combustion chamber of the engine, and a auxiliary carburetor C ₃ that supplies a rich mixture to the auxiliary combustion chamber of the engine are arranged in parallel, and the In a multiple carburetor in which each main carburetor is formed with air vents 3 ₁ and 3 ₂ for adjusting the pressure in the space above the fuel oil level of each float chamber a ₁ and a ₂ in these main carburetors, The spaces a ₁ , a ₂ , a ₃ above the fuel oil level of the adjacent main or sub-vaporizers are communicated with each other via communication pipes 4 and 5 , and the main vaporizer C ₁ , of the communication pipes 4 and 5 are connected to each other through communication pipes 4 and 5 . Each end 4a, 5a on the _C2 side projects horizontally from the inner wall surface of the float chambers ₂₁ , ₂₂ , and these projecting ends 4a, 5a
A multiple vaporizer characterized in that the protruding length of each part of the vaporizer increases as it goes downward.