JP3909631B2 - Vaporized fuel processing apparatus for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a processing apparatus that prevents the evaporative fuel (mainly gasoline vapor) generated in a fuel tank of a vehicle from being released to the outside and does not affect combustion control.
[0002]
[Prior art]
In gasoline-powered vehicles, gasoline vapor generated in the fuel tank is prevented from being released into the atmosphere when the vehicle is stopped or running for the purpose of preventing pollution, but an example for this is shown in FIG. Yes, a check valve 3 that keeps the pressure in the tank 1 in the middle of the upper space of the fuel tank (hereinafter simply referred to as the tank) 1 and the carbon canister 2 A charging mechanism that connects the first ventilation line Ra, which allows air to pass when pressure is applied, and causes gasoline vapor generated in the tank 1 when the vehicle is stopped or running to be sent to the canister 2 filled with activated carbon and adsorbed to the activated carbon. And a gate valve 4 that opens and closes by inserting and extracting the oil supply nozzle N in the inlet pipe 1a of the tank 1, and this gate valve 4 is connected to the second ventilation line Rb. Connected to the liquid level sensing valve 5 provided in the tank 1 and connected to the first ventilation line Ra in the vicinity of the canister 2, and the gasoline vapor generated when the gasoline is replenished is sent to the canister 2 and supercharged to the tank 1. Is connected to the intake pipe K of the engine E through the purge pipe Rc and the negative pressure introduction path Rd, and the adsorbed gasoline is sucked in air from the air inlet 2a of the canister 2 by the negative intake pressure during the operation of the engine E. And a purge mechanism for separating the gas and feeding it into the intake pipe K.
[0003]
[Problems to be solved by the invention]
By the way, regulations on vehicle exhaust gas are in the direction of strengthening from the viewpoint of environmental protection, and engine combustion control is becoming more sophisticated due to improvements in fuel consumption rate and operability (rapidity, fidelity). If the gasoline vapor adsorbed and held in the canister is sent to the engine and burned, as in the conventional gasoline vapor processing device, the air-fuel ratio of the air-fuel mixture goes wrong and the above object can be achieved. If you try to suppress the change in air-fuel ratio, the canister performance recovery will be delayed, and the canister will carry excess gasoline vapor, and the gasoline vapor will be released to the outside through the air vent There is.
[0004]
Therefore, the present invention does not send the gasoline vapor adsorbed on the adsorber to the fuel tank, returns it to the fuel tank, promotes liquefaction, and does not affect the combustion control of the engine. It is an object of the present invention to provide an evaporative fuel processing apparatus that is not likely to be released to the outside.
[0005]
[Means for Solving the Problems]
Based on the above problems, the present invention is a fuel vapor processing apparatus in a vehicle. First, an upper space of a fuel tank is provided with a steam control valve in the middle at one end of an adsorption container containing an adsorbent such as activated carbon. A first ventilation line connected to the fuel tank, a second ventilation line connected to the fuel tank refueling pipe, and a purge pipe provided with a vacuum pump in the middle, and the tip of the purge pipe connected to the fuel The upper end provided inside or outside the tank is closed and the bottom part is inserted into an airtight contact cylinder that leads to the tank bottom part via a check valve, with its tip facing the cylinder bottom part, and in the upper space part of the fuel tank, A pump means connected to the upper end of the gas-liquid contact cylinder by a thin tube and operated by liquid fuel returning from a return line of fuel supplied to the engine is disposed. The pump means is operated by the liquid fuel returned from the return pipe while being separated by the vacuum pump, and the liquid fuel in the gas-liquid contact cylinder is continuously replaced so that the fuel vapor is supplied to the liquid fuel. Secondly, the pump means is connected to the upper end of the gas-liquid contact tube by a narrowed nozzle and a thin tube at the tip of the return pipe and opposed to the nozzle on the lower side. It is characterized by being formed as a jet pump with a suction chamber having a spreading pipe.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an example of a processing apparatus according to the present invention. Reference numeral 11 denotes a fuel tank (hereinafter simply referred to as a tank), and an upper space inside thereof is a steam control valve 13 by a ventilation line La in the first first half. The steam control valve 13 is connected to one end portion of the adsorbent vessel 12 by the first second half ventilation line Lb, and one end portion of the adsorbent vessel 12 is connected to the oil supply pipe 11a of the tank 11. A second ventilation line Lc communicating with the on-off valve 17 and a purge line Ld provided with a vacuum pump 14 in the middle are connected so as to communicate with each other.
[0007]
The steam control valve 13 is a spring-biased diaphragm type, and opens and closes the inlet end of the first-second ventilation passage Lb depending on the steam pressure of gasoline present in the tank 11 . A one-way check valve 16 that communicates with the atmosphere is connected in the middle of the ventilation line La in the first half that communicates when the inlet end is opened, and the inside of the tank 11 becomes negative pressure. Has been made to prevent.
[0008]
A predetermined amount of adsorbent S such as granular, lump, honeycomb activated carbon, ceramic or other inorganic adsorbent or organic polymer adsorbent is accommodated in the adsorbent vessel 12, and above and below the filter The member 12a and the perforated plate 12b are disposed and held, and the other end of the adsorbent vessel 12 is provided with an air exhaust line Le having an electromagnetic valve 18 in the middle, and the electromagnetic valve 18 and a vacuum. The pump 14 is electrically connected to the controller 20.
[0009]
On the other hand, a gas-liquid contact cylinder 15 having a predetermined height (about 10 cm) with its upper end closed is erected in the tank, and the front end portion of the purge line Ld is inserted into the gas liquid contact tube 15. Is close to the bottom of the cylinder so that the gasoline vapor is sufficiently brought into contact with the liquid gasoline introduced in the gas-liquid contact cylinder 15 as described later, and is effectively liquefied and absorbed. Dispersing tools 19 such as a netting material and a filter for speeding up absorption into the water are attached.
[0010]
Further, a pump 21 for supplying fuel to the engine via a supply line Lf is disposed in the tank 11 (however, the pump 21 may be provided outside the tank), and a return line for surplus fuel. The tip portion of Lg is narrowed down to form a nozzle n, and is inserted into a funnel-shaped suction chamber 15a connected to the upper end of the gas-liquid contact tube 15 via a thin tube 15c and extends in the lower side of the suction chamber 15a. The nozzle n, the suction chamber 15a, and the spreading pipe 15b form one jet pump that faces the base end of the spreading pipe 15b.
[0011]
A check valve 23 is attached to one side of the bottom of the gas-liquid contact cylinder 15 so as to open only in the direction from the tank side to the cylinder side and close in the reverse direction. Is provided and communicated with the on-off valve 17 on the oil supply pipe 11a through the pipe line Lh.
[0012]
Therefore, at the beginning of use of the vehicle, if gasoline is injected into the tank 11 by inserting a fuel nozzle into the fuel pipe 11a, a part of the gasoline entering the tank 11 pushes the check valve 23 open. The gas-liquid contact cylinder 15 is entered, and a predetermined amount of liquid gasoline is stored inside the tank 11, and at the same time, the upper space in the tank 11 is filled with gasoline vapor.
[0013]
In this state, when the temperature rises in the tank 11 or the pressure of the gasoline vapor exceeds a predetermined pressure, the diaphragm of the steam control valve 13 is pushed open through the ventilation line La in the first first half, and the first second half. The adsorbent container 12 passes through the ventilation line Lb and is adsorbed by the adsorbent S in the container. On the other hand, the gasoline vapor generated at the time of refueling enters the adsorbent container 12 through the second ventilation pipe Lc directly from the on-off valve 17 or through the pipe Lh and the on-off valve 17 and enters the adsorbent S. To be adsorbed. When refueling or when the vehicle is stopped, the solenoid valve 18 is opened, and the air that has entered the adsorbent container 12 together with the gasoline vapor is released into the atmosphere through the discharge pipe Le.
[0014]
When the engine is started when the vehicle is operated, the solenoid valve 18 is closed by the controller 20 and the vacuum pump 14 is operated at the same time, and the gasoline vapor adsorbed on the adsorbent S is released by the vacuum action, and the purge pipe It passes through the path Ld, goes to the bottom of the gas-liquid contact cylinder 15 provided in the tank 11, is reduced in size by the disperser 19 and flows out, and is liquefied and absorbed by contact with liquid gasoline for a predetermined time.
[0015]
When the engine is started, surplus liquid gasoline supplied to the engine is returned to the tank 11 side by the return line Lg. At this time, the tip of the return line Lg is at the upper end of the gas-liquid contact cylinder 15. Since the nozzle n is formed in the connected suction chamber 15a, the returned liquid gasoline is ejected in the suction chamber 15a, and the liquid gasoline in the gas-liquid contact cylinder 15 is sucked through the thin tube 15c by the negative pressure generated thereby. Then, it flows out into the tank 11 from the spreading pipe 15b. At the same time, liquid gasoline in the tank 11 opens the check valve 23 and enters from the bottom of the gas-liquid contact cylinder 15, and the cylinder 15 is fully filled with liquid gasoline so as to maintain sufficient contact with the gasoline vapor. As the liquid gasoline is continuously replaced.
[0016]
In general, the temperature of the returned liquid gasoline is about 4 to 6 ° C. higher than that of the gasoline in the tank 11, but the liquid gasoline in the gas-liquid contact cylinder 15 is more suitable than the return liquid gasoline returned directly into the gas-liquid contact cylinder. The temperature can be kept low, and it will promote the liquefaction absorption of gasoline vapor. In addition, during the operation of the engine, gasoline vapor having a predetermined pressure or higher generated in the tank 11 is directed to the adsorbent container 12 through the first ventilation pipelines La and Lb. It is returned to the tank 11 through the purge line Ld without being adsorbed.
[0017]
On the other hand, if the pressure in the tank 11 becomes equal to or lower than the predetermined pressure, the diaphragm of the steam control valve 13 closes the ventilation line Lb in the first second half, and if the pressure in the tank 11 becomes negative, the check valve 16 opens. As a result, air is introduced into the tank 11 and damage to the tank 11 is prevented.
[0018]
And even when the liquid level around the gas-liquid contact cylinder is low when the engine is stopped, the liquid level in the gas-liquid contact cylinder 15 is kept high by the check valve 23. The ability to absorb gasoline vapor during engine operation is not reduced.
[0019]
When the gasoline vapor adsorbed on the adsorbent S is released, a jacket J is formed around the adsorbent vessel 12 as shown by a one-dot chain line in FIG. 1, and cooling water having a high temperature (about 80 ° C.) is fed to the radiator. Alternatively, if the electric heater is provided and the container 12 is heated by the controller 20 when the gasoline vapor is released, the removal of the gasoline vapor is promoted.
[0020]
FIG. 2 shows a modified example in which the gas-liquid contact cylinder 15 is disposed in the vicinity of the outside of the tank 11, which is configured such that the suction chamber 15 a that forms a jet pump is formed in the tank 11 at the upper end of the gas-liquid contact cylinder 15. A thin tube 15c that extends from the inside of the tank is extended outward, and the bottom of the tank and the bottom of the gas-liquid contact tube 15 are connected by another thin tube 15d, and the check valve 23 as described above is disposed in the middle. The tip of the liquid gasoline return line Lg is in the suction chamber 15a to form the nozzle n, and the connection state of the purge line Ld and the like is the same as in the example of FIG. 1, and its function is not changed. However, in this case, since the gas-liquid contact cylinder 15 is separated from the tank 11, it is easy to select whether or not to install the processing device depending on the destination of the vehicle (sales location). A processing apparatus can be mounted without being affected by the difference in the shape of the tank 11, and versatility can be improved.
[0021]
When the cooling device C using the air conditioner refrigerant or the like is provided at the bottom of the tank as shown by the dotted line in FIG. 1 so that the cooled liquid gasoline enters the gas-liquid contact cylinder, the atmospheric temperature is high. Even under high-load operation for a long time and the temperature of the fuel in the tank 11 increases, liquefaction of gasoline vapor is promoted and effective.
[0022]
【The invention's effect】
Since the present invention is configured as an evaporative fuel processing apparatus in a vehicle as in claims 1 and 2, the fuel vapor generated in the fuel tank can be reliably returned to the fuel tank and may be released into the atmosphere. Therefore, it is possible to help prevent environmental pollution, and since fuel vapor is not sent to the engine, it is possible to achieve advanced combustion control without disturbing the air-fuel ratio of the air-fuel mixture. During operation, the liquid fuel in the gas-liquid contact cylinder can be continuously replaced with the liquid fuel around the cylinder, without causing an increase in the temperature of the liquid fuel in the cylinder and without reducing the fuel vapor absorption capacity. Furthermore, since the return fuel from the engine is used to replace the liquid fuel in the gas-liquid contact cylinder, no special energy means is required, and production can be performed at low cost. Further, if the jet pump is used as the pump means as in claim 2, since there is no rotating means, the structure is simple, the noise is low, and the production can be made at a lower cost.
[Brief description of the drawings]
FIG. 1 is a system diagram of an example of an evaporative fuel treatment apparatus according to the present invention.
FIG. 2 is a system diagram of another example.
FIG. 3 is a system diagram of a conventional processing apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Fuel tank 11a Oil supply pipe 12 Adsorber container 13 Steam control valve 14 Vacuum pump 15 Gas-liquid contact cylinder 15a Suction chamber 15b Widening pipe 15c Narrow pipe 17 On-off valve 21 Fuel supply pump 23 Check valve La Ventilation in the first half Pipe line Lb Ventilation line Lc in the first second half Second ventilation line Ld Purge line Lg Return line n Nozzle S Adsorbent

Claims (2)

A first ventilation line connected to the upper space part of the fuel tank provided with a steam control valve in the middle at one end of an adsorption container containing an adsorbent such as activated carbon, and a second bench connected to the fuel tank refueling pipe And a purge line with a vacuum pump arranged in the middle, the tip of the purge line is provided inside or outside the fuel tank, the upper end is closed, and the bottom is connected to the tank bottom via a check valve. Inserted into the gas-liquid contact cylinder, the tip of the cylinder faces the bottom of the cylinder, and the upper space of the fuel tank is connected to the upper end of the gas-liquid contact cylinder by a thin tube and returned from the return line of the fuel supplied to the engine. The pump means that operates by the liquid fuel is disposed, and when the engine is operated, the fuel vapor adsorbed by the adsorbent is separated by the vacuum pump and led to the gas-liquid contact tube, while the liquid returning from the return pipe It said pump means is operated and interchanged liquid fuel of the gas-liquid contact cylinder continuously, the processing device of the evaporated fuel of the fuel vapor in the vehicle, characterized in that so as to absorb the liquid fuel by the charges. The above-mentioned pump means is formed as a jet pump with a narrowed nozzle at the tip of the return pipe and a suction chamber having a spreading pipe that is connected to the upper end of the gas-liquid contact cylinder and faces the nozzle on the lower side by a narrow pipe. The apparatus for treating evaporated fuel in a vehicle according to claim 1, wherein:

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