JPS5915658A - Device for preventing percolation of carbureter - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a spewing phenomenon and to prevent percolation of a carbureter, by causing the air to flow through a float chamber when an engine stops its running. CONSTITUTION:Vent pipes 6a and 6b are connected to the parts above the surfaces of oil in float chambers 5a and 5b, respectively, communicated from an air passage 4 to a primary side and a secondary side through a passage 10. An orifice 7, which regulates the negative pressure in a suction pipe through leak of a part of the negative pressure, is provided at the open end on the air passage side of the one vent pipe 6a, and the end is communicated with a suction pipe 2 through a passage 8. If the negative pressure in the suction pipe is intense as at an idling time and in the case of running at a low speed, a difference in the pressure between the negative pressure regulated by the orifice 7 and the approximate atmospheric pressure is produced, and as a result, an air flow passage 9 causes the air to flow from the air passage 4 to the suction pipe 2 side through the float chambers. This prevents the occurrence of a spewing phenomenon due to a fluctuation in the surface level of oil.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a dual carburetor of a vehicle internal combustion engine, in which a large amount of fuel vapor is generated mainly in the float chamber at high temperatures. Regarding the prevention device.

Under high-temperature conditions such as summer, the engine's carburetor always stores a certain amount of fuel, and the flow chamber becomes heated; however, when operating at high speeds, the fuel inlet/outlet of the engine chamber becomes heated. Since the fuel is heated rapidly, there is no time for the fuel to heat up in the foot chamber, and problems such as percolation do not occur. On the other hand, during idling and low-speed driving, the fuel stays in the float chamber for a relatively long time, so it is heated and the temperature rises, producing a large amount of fuel vapor. During idling, fuel vapor seeps into the air-fuel mixture passage, resulting in a superfluid mixture, resulting in poor operation, and when driving at low speeds, vapor bubbles block the fuel passage, causing intermittent flow of fuel from the main nozzle, etc. There was a problem with percolation, such as poor running due to the impact.

In addition, at such high temperatures, the fuel I in the fuel pipe becomes high, and when the engine is started, the fuel enters the flow 1 chamber with force, and as a result, the fuel in the flow 1-1-1 is drained of Rb. There were also problems with the air-fuel mixture passageway side, such as the blowout and the so-called Spi+ and -ing phenomena.

By the way, in the past, as a measure to prevent the above-mentioned par]21 engine, there were measures such as using heat shields and insulators to block radiant heat and conductive heat from the engine body to the carburetor, and cooling the carburetor with a cooling fan. The temperature of the vaporizer float chamber is 1.
A method of suppressing hits is used. However,
In recent years, the shape of car bodies has become streamlined to take into account air resistance, and with the adoption of front-engine front-drive cars, the number of parts in the engine room has increased significantly, and as a result, there is less room in the engine room. The effect of the above-mentioned heat shield plate, etc., which moves while ensuring ventilation, is also reduced, and there is a tendency for percolation to occur.

In addition, as a treatment measure for fuel vapor actually generated, for example, Japanese Utility Model Application Publication No. 55-139256, Japanese Utility Model Application Publication No. 54i-44
As in the prior art of Publication No. 003, when the engine is stopped, the
- Some devices connect the exhaust chamber to a fuel vapor adsorption device such as a chitonister. However, this method cannot deal with the generation of fuel vapor after the engine is restarted. Furthermore, the current situation is that no effective measures have yet been taken to prevent viewing.

In view of these circumstances, the present invention has been developed by reducing the air flow to the original size through the flow chamber when the engine is stopped.

- In addition to quickly removing fuel vapor that has already been generated, it is also possible to directly suppress newly generated fuel vapor by utilizing the endothermic effect that occurs when fuel vaporizes. Prevents vaporizer bar lusion! The goal is to provide equipment.

For this purpose, the device according to the invention comprises: - dual vaporizer B
When two vent vibes are connected to the primary and secondary float chambers that communicate with each other through a common air passageway in C5, connect the wooden vent pipe to the negative pressure adjustment orifice. Both communicate with the suction pipe side, and due to the pressure difference between the adjusted negative pressure of the suction pipe negative pressure and the approximately popular Li- on the air passage side, pen 1 to
By using a pipe, an air circulation system is constructed in which air flows from the air passage to the suction pipe from the float chamber to the suction pipe, preventing spewing by the air flow in the float chamber, and further reducing the combustion steam to IJIjij-1. It is characterized in that it not only reduces the amount of fuel vapor generated, but also suppresses the generation of new fuel vapor.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. In FIG.
2 is a suction pipe, and there is a common air passage 4 on the L flow side of the bench 2 3a on the downstream side and the venturi 3b on the secondary side,
Vent pipes Ga and (3b) are connected to the upper part of the oil level of the flow chambers 5a and 5b, which communicate from the air passage 4 to the primary side and the secondary side phase U via the passage 10, respectively.
There is.

Therefore, in such a configuration, a part of the negative pressure of the suction pipe is leaked to the air passage side opening end of the vent purve 6a of one of the vibrators Ga and 6b to the two pens 1, and the negative pressure is reduced to zero. An orifice 7 is provided to adjust the pressure, and its end communicates with the C suction pipe 2 via the passage VR8.In this way, the negative pressure in the suction pipe is maintained, such as when the engine is idling and running at low speed. If it is large, from air passage 4 to pen 1
~ Vibro J Float? 5b, 5a, a vent vibro a, and an air circulation system path 9 that connects the passage 8 to the suction pipe 2.

Because of this configuration, when the suction pipe C1 pressure is high, such as when the engine is idling or running at low speed, the adjusted negative pressure regulated by the orifice 7 will be equal to the approximately atmospheric pressure in the air passage 4. By generating a pressure peak during this period, air flows from the air passage 4h opening to the suction pipe 2 side through the float chamber through the air circulation system path 9. In other words, the orifice effect has J,
The air does not flow directly to the air passage 47'+113 vent vibro a, and the vent vibro 11. F1
An air passage is formed that flows from the 1-t chamber, the pent vibro a, and the air passage 8 to the suction pipe, and furthermore, when the vent vibrator Ga, 61> is clogged, the air passage 81 from the air passage 4 is As the air flows
Inhalation of fuel lit into the suction pipe is prevented. When the temperature is high, even if the pressure applied to the fuel in the fuel pipe is J-'7/ and the fuel flows vigorously into the float chamber 5b, the ejection pressure is reduced by the air flow, and the pressure applied to the fuel in the fuel pipe is reduced by the fluctuation of the C1 oil level. ] - the ink phenomenon is prevented. In addition, if fuel 1'81 steam has already accumulated in the exhaust chambers 5a and 511, it is immediately discharged and the flow [-chamber!ia
.

Since the atmosphere inside 5b is brought to an unsaturated state by the air flow, vaporization on the surface is promoted when the fuel temperature is high. (Hang it up, and the heat of vaporization will cause it to burn.)
The temperature of the 1st surface is directly lowered, and the entire fuel 1゛V on C4' causes convection, and self-cooling progresses.
In this way, generation of new fuel vapor is suppressed.

1,/,=, A double carburetor equipped with a float chamber on one side is shown in FIG. 2 as a second embodiment, and in this case as well, the same effects can be obtained.

In the high-speed operation C', the suction pipe negative pressure becomes small and no pressure difference is created between the adjusted negative pressure and the engine suction internal pressure of the air passage 4, so that the above-mentioned effect is not performed.

As is clear from the above description, according to the present invention, the flow 1-chambers 5a, 51 are removed during idling and low-speed driving, which have a large effect on engine operation, such as percolation.
Since the air is flowed through the air, spiking is reliably prevented during high-grade products, and the fuel vapor that has already been generated is exhausted, and new vapor is directly absorbed by the heat absorption effect accompanying the promotion of fuel vaporization. suppressed, percolation can be effectively prevented. Two or more vent vibros of a double-barreled vaporizer a
, (ib, It has a structure that utilizes the pressure difference between the adjusted negative pressure of the suction pipe n pressure and the atmospheric pressure of the air passage 4, and the flow 1 to
Since the vaporized fuel in the chambers 5a and 5b is also sucked in and used for combustion, there is no problem of fuel contamination and the setting of the vaporizer is easy. In cases where there is no possibility of occurrence of par-resin 1, such as during high-speed operation, the air flow in the float chambers 5a, 5b will almost disappear, which is preferable.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a first embodiment of the apparatus according to the present invention, and FIG. 2 is a cross-sectional view of the second embodiment. 1...Dual carburetor, 2...Intake air, 3a, 3+
1... Bembukoli, 4... Air passage, 5a, 5
1+...Chamber to flow 1, 6a. Gb...Pen 1~pipe, 7...A refill, 8.
...Aisle, 9...Air distribution system path, 10...Aisle. Special r "Applicant: Tomi", Heavy Industries Co., Ltd., Patent attorney Nobuko Kobashi, Patent attorney: Tsuki Mura, "No. 1"
Figure 1゜ Figure 112

Claims (1)

[Claims] Venturi J - In a device in which two or more vent pipes are installed in series between the air passage on the flow side and the upper oil level of the chamber to flow 1, one of the two or more vent pipes is connected to the pen 1. -An air flow system with an A-refrigerator for negative pressure adjustment installed at the mouth end of the pipe on the air passage side, and communicating with the suction pipe through a passage, from the air passage to the suction pipe via the float chamber via a vent pipe. A vaporization prevention device for a vaporizer, characterized by comprising: