KR0169896B1 - Fuel evaporate gas control system of an automobile - Google Patents

Abstract

The present invention relates to an evaporative gas control system having a liquid fuel return structure, and particularly to prevent the condensed fuel of the evaporated gas from increasing the ventilation resistance on the pipeline when the pipeline between the canister and the engine is increased, thereby preventing the purge efficiency from dropping. The present invention relates to a boil-off gas control system having a return structure of condensed liquid fuel which can be easily enlarged in size and can easily cope with boil-off gas regulation.

The system of the present invention is an evaporation gas control system for supplying evaporated gas collected from a canister to an engine by evaporation from a fuel tank, according to an opening of a purge control valve, wherein the liquid fuel is installed between the canister and the purge control valve and liquefied in a pipeline. It is characterized in that it comprises a liquid fuel collecting means for returning to the fuel tank when the collected liquid fuel is collected by a predetermined amount or more.

Description

Evaporative Gas Control System with Liquid Fuel Return Structure

The present invention relates to an evaporation gas control system having a liquid fuel return structure, in particular, when the conduit between the canister and the engine is long, condensed fuel of the evaporation gas on the conduit increases the ventilation resistance and prevents the purge efficiency from dropping. The present invention relates to a boil-off gas control system having a return structure of condensed liquid fuel which can be made large in size and can easily cope with boil-off gas regulation.

Liquid fuel used as a vehicle fuel is supplied to the engine by a fuel pump while stored in a fuel tank. In this case, the fuel tank is filled with liquid fuel, that is, HC gas evaporated from gasoline or diesel.

The boil-off gas is emitted from the fuel tank to the atmosphere when the lid is opened when refueling or when the vehicle is driven or stopped due to incomplete sealing of the fuel inlet, causing optical smog and respiratory failure of the human body. It is a factor.

Accordingly, each country regulates the amount of pollutants in the combustion exhaust gas and at the same time regulates the emission of the boil-off gas to below a certain level.

A conventional boil-off gas control system for reducing the air emissions of boil-off gas and saving fuel is shown in FIG.

The boil-off gas control system shown in FIG. 1 is installed in the fuel tank 1 to prevent the fuel from entering the charcoal canister, and to store the boil-off gas in the fuel tank 1 when the engine is stopped. A purge control solenoid valve 9 for adjusting the amount of evaporated gas supplied from the canister 5 to the intake manifold 7 according to the control of the charcoal canister 5 and the engine control unit ECU, and the ECU for system control. It consists of (11). Reference numeral 13 is a check valve for adjusting the pressure of the fuel tank (1).

The evaporation gas control system collects the HC gas evaporated from the fuel tank 1 into the canister 5 and purge control solenoid valve 9 so that the ECU 11 can maintain the best engine operating state according to the engine operating state. By controlling the control amount of the boil-off gas supplied to the intake manifold (7).

However, in the system, since the pipeline between the canister and the engine is composed of a hose / pipe / tube, etc., when the ambient temperature falls on the pipeline, the evaporated gas may be condensed into a liquid. In this case, the condensed liquid fuel reduces the cross-sectional area of the conduit to increase the ventilation resistance, thereby reducing the purge efficiency.

Moreover, in order to cope with the new evaporation gas and ORVR (On Board Refueling Vapor Recovery) regulations in North America, as the canister is enlarged, it is installed at the rear of the vehicle (around the fuel tank) for ease of installation. In this case, however, the pipeline between the canister and the engine is lengthened, which adds to the seriousness. In addition, as the canister becomes larger, the supply amount of the boil-off gas flowing into the engine also increases, which makes it difficult to control the air-fuel ratio (A / F).

The present invention has been made in view of the above-described problems of the prior art, the object of which is to prevent the condensed fuel of the boil-off gas on the conduit increases the ventilation resistance when the conduit between the canister and the engine is long to prevent the purge efficiency is lowered As a result, the canister can be easily enlarged to cope with the regulation of new evaporation gas, and the control of air-fuel ratio can be easily controlled by reducing the evaporation gas flowing into the engine, and condensation can be saved by returning the condensed fuel. To provide a boil-off gas control system having a return structure of liquid fuel.

1 is a control system diagram of a conventional boil-off gas control system.

2 is a control system diagram of an evaporative gas control system having a liquid fuel return structure according to the present invention.

3 is a cross-sectional view showing the vapor chamber structure of FIG.

* Explanation of symbols for main parts of the drawings

1: fuel tank 3: separator

5: canister 7: intake manifold

9: Purge Control Valve 11: ECU

13: check valve 21: vapor chamber

23: 1 way check valve 25: 4th pipe

27: first duct 29: second duct

31: 3rd corridor 33: entrance

35: upper exit 37: lower exit

39 chamber chamber 41 partition plate

43: hole 45: steel ball

47: leaf spring 49: upper chamber

In order to achieve the above object, the present invention is provided between the canister and the purge control valve in the evaporation gas control system for supplying the evaporated gas collected in the canister evaporated from the fuel tank to the engine according to the opening of the purge control valve. And a liquid fuel collecting means for collecting the liquid fuel liquefied in the pipeline and returning the collected liquid fuel to the fuel tank when the amount of the collected liquid fuel is more than a predetermined amount. .

According to the present invention, the liquid fuel collecting means has an inlet connected to the canister through a first conduit, a first outlet for boil-off gas is connected to the purge control valve through a second conduit, and a second outlet for liquid fuel is provided. A chamber housing connected to the fuel tank through a third conduit, a split plate dividing the inside of the chamber housing up and down, a steel ball blocking a hole formed in the split plate from below, and the steel ball at the tip end portion thereof. It consists of a leaf spring fixed to the elastically blocking the hole.

As described above, the present invention captures the condensed liquid fuel generated on the boil-off gas line by the vapor chamber constituting the liquid fuel collecting means installed on the conduit between the canister and the purge control valve, and feeds back the liquid fuel when a predetermined amount or more is collected. Return to the fuel tank through the line.

Therefore, when the canister is installed near the fuel tank and the pipeline between the canister and the engine is long, condensed fuel of the boil-off gas increases the aeration resistance and prevents the purge efficiency from dropping. Therefore, the canister can be easily enlarged. Responding to the regulation of new evaporation gas can be facilitated, control of the air-fuel ratio is facilitated by the reduction of the boil-off gas flowing into the engine, and the fuel can be reduced according to the return of the condensed fuel.

EXAMPLE

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

2 is a control system diagram of an evaporative gas control system having a liquid fuel return structure according to the present invention, and FIG. 3 is a cross-sectional view of the vapor chamber of FIG. 2, and as shown in FIG. ) Is connected to the canister (5) for collecting the boil-off gas through the two-way check valve (13) for tank pressure adjustment on the first conduit (27), and the outlet of the canister (5) is connected to the second conduit (29). It is connected to the inlet of the vapor chamber 21 through, the upper outlet of the vapor chamber 21 is connected to the purge control valve 9 through the third conduit 31, the lower outlet of the vapor chamber is the fourth conduit (25) Is returned to the fuel tank (1). In addition, the outlet of the purge control valve 9 is connected to the engine or surge tank, it is opened and closed under the control of the ECU.

In addition, in the vapor chamber 21, the inlet 33 is connected to the second conduit 29, the upper outlet 35 is connected to the third conduit 31, and the lower outlet 37 is the fourth as shown in FIG. 3. The chamber housing 39 connected to the conduit 25, the partition plate 41 for dividing the inside of the chamber housing up and down, and the hole 43 formed in the center of the partition plate 41 are blocked from below. The steel ball 45 and the steel ball 45 is fixed to the front end portion and is composed of a leaf spring 47 that is elastically blocking the hole.

It will be described below in detail the operation of the boil-off gas control system of the present invention configured as described above.

In the system of the present invention, when the evaporated gas evaporated from the fuel tank 1 becomes higher than a predetermined pressure, it is collected in the canister 5 through the two-way valve 13 on the first conduit 27. In this case, the canister can be installed around the fuel tank 1 by greatly increasing the capture capacity of the boil-off gas.

The vaporized gas collected in the canister 5 is then vaporized under the control of the ECU. The purge control valve 9 opens and is supplied to the intake manifold of the engine via the second long passage 29 to the vapor chamber 21. Will go through.

At this time, the liquid fuel condensed in the vapor chamber 21 and the liquid fuel condensed on the second conduit 29 are collected in the upper chamber 49 of the vapor chamber 21. Then, when a certain pressure is applied to the steel ball 45 by the collected liquid fuel, the leaf spring 47 is struck, and the hole 43 blocked by the steel ball 45 is opened to connect to the fourth pipe from the lower outlet 37. Return to the fuel tank (1) through (25). Meanwhile, the evaporated gas collected in the upper chamber is absorbed into the intake manifold on the engine side through the purge control valve 9 on the third conduit 31.

In the present invention, the steel plate is fixed plate spring and the split plate formed with a hole that is opened and closed by the steel ball has a one-way shock valve function.

This structure feeds the liquefied liquid fuel back to the fuel tank without a separate control device except the vapor chamber.

As described above, the present invention captures the condensed liquid fuel generated on the boil-off gas line by the vapor chamber installed on the pipeline between the canister and the purge control valve, and when the collected liquid fuel becomes a certain amount or more, it feeds into the fuel tank through the feedback line. Return.

Therefore, it is possible to increase the purge efficiency by reducing the aeration resistance caused by condensed fuel on the pipeline between the canister and the engine. Accordingly, the canister can be easily enlarged to cope with the regulation of new evaporation gas. The reduction makes it easier to control the air-fuel ratio, and the fuel can be reduced according to the return of the condensed fuel.

In the above, the present invention has been illustrated and described with reference to specific preferred embodiments, but the present invention is not limited to the above-described embodiments and is not limited to the spirit of the present invention. Various changes and modifications can be made by those who have

Claims (2)

An evaporative gas control system for evaporating gas evaporated from a fuel tank and collected in a canister to an engine according to an opening of a purge control valve, wherein the liquid fuel disposed between a canister and a purge control valve is collected and collected on a pipeline. Evaporating gas control system having a liquid fuel return structure, characterized in that the liquid fuel collecting means for returning to the fuel tank when the amount of the liquid fuel is a predetermined amount or more. The liquid fuel collecting means of claim 1, wherein the liquid fuel collecting means has an inlet connected to the canister through a first conduit, and a first outlet for boil-off gas is connected to the purge control valve through a second conduit. A chamber housing having an outlet connected to the fuel tank through a third conduit, a split plate dividing the inside of the chamber housing up and down, a steel ball blocking a hole formed in the split plate from below, and the steel ball An evaporative gas control system having a liquid fuel return structure, characterized in that the spring is fixed to the front end and is elastically blocking the hole.