JPH0874683A - Failure diagnosis device for evaporative emission control system - Google Patents

Abstract

PURPOSE: To surely warn a driver of any abnormality so that the abnormal state can be quickly coped with by providing a control means to which a detection signal from a sensor and an opening/closing signal for a switch portion are input and which, when a cover is open during driving, outputs a control signal to a warning means. CONSTITUTION: A cover 28 is provided at the fuel supply hole 26 of a fuel tank 6, and the opening and closing action of a switch portion 22 is synchronized with the opening and closing action of the cover 28; i.e., the switch portion 22 is closed by opening of the cover 28, to open a bent cut valve 20. An engine speed sensor for detecting engine speed NE and a vehicle speed sensor for detecting vehicle speed are provided, and a control means ECU 30 to which detection signals from the sensors and an opening/closing signal for the switch portion 22 are input is provided. If the cover 28 is open during driving, the control means 30 outputs a control signal to a warning means 32 to warn of an abnormal state where the cover 28 is open.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure diagnostic device for an evaporative emission control system, and more particularly to a failure diagnostic device for an evaporative emission control system that prevents forgetting to close a lid of a fuel supply port of a fuel tank.

[0002]

2. Description of the Related Art Evaporative gas (evaporation) leaking into the atmosphere from a fuel tank, a float chamber of a vaporizer, etc., contains a large amount of hydrocarbons (HC) and is one of the causes of air pollution. Various techniques are known to prevent this because it also leads to loss. As a typical example, the canister containing an adsorbent such as activated carbon once adsorbs and holds the evaporative gas in the fuel tank, and the evaporative gas adsorbed and held in the canister is released (purged) during operation of the internal combustion engine to remove the internal combustion gas. There is an evaporative system that supplies the engine.

A failure diagnostic device for the evaporative emission control system is disclosed in Japanese Patent Application Laid-Open No. 61-283756. The evaporative fuel processing apparatus disclosed in this publication has a first canister that communicates with a fuel tank via a small diameter passage and a second canister that communicates with a fuel tank via a large diameter passage. And the respective canisters can be independently communicated with the intake passage of the engine through the purge valve for evaporative fuel purging, and the first canister and the second canister are communicated with each other, and the fuel tank is in a refueling state in the communicating passage. A control valve is provided, which is released at a certain time, but is closed in the purged state of the evaporated fuel, and the capacity shortage of one canister is covered by the capacity of the other canister.

[0004]

By the way, in the conventional failure diagnostic apparatus for the evaporative emission control system, as shown in FIG. 6, the canister 504 of the failure diagnostic apparatus 502 for the evaporative emission control system is replaced by the intake air of an internal combustion engine (not shown). aisle,
That is, the purge passage 508 is connected to the intake system, and the large-diameter first evaporation passage 510 and the small-diameter second evaporation passage 512 are connected to the fuel tank 506.

Further, an atmosphere passage 514 for opening to the atmosphere is provided in the canister 504, and in the middle of this atmosphere passage 514,
Open / close valve 516 and air filter 5 from the canister 504 side
18 and 18 are provided.

A vent cut valve 520 is provided in the middle of the large-diameter first evaporation passage 510, and a battery 524 is connected to the vent cut valve 520 via a switch section 522 to open / close the vent cut valve 520. Set up.

A fuel supply port 526 of the fuel tank 506.
Is provided with a lid portion 528 for opening and closing the fuel supply port 526,
The opening / closing operation of the switch 522 is interlocked with the opening / closing operation of the lid 528. That is, by opening the lid part 528, the switch part 522 is closed and the vent cut valve 520 is opened.

Further, a first float rollover valve 53 is provided at an opening portion of the first evaporation passage 510 on the fuel tank side.
6 is provided, and the second float rollover valve 53 is provided at the fuel tank side opening of the second evaporation passage 512.
8 are provided.

When the lid portion 528 of the fuel tank 506 is opened during refueling, the switch portion 522 is closed and the vent cut valve 520 is opened. And at this time,
When fuel is supplied from the fuel supply port 526 into the fuel tank 506, the vaporized gas generated in the fuel tank 506 is adsorbed to the canister 504 via the vent cut valve 528.

However, when the lid 528 is released while the vehicle is traveling due to forgetting to tighten the lid 528, the switch 522 is closed and the vent cut valve 520 is closed.
Has been released.

As a result, the evaporated gas generated in the fuel tank passes through the two evaporation passages and is adsorbed by the canister, so that the evaporated gas is adsorbed by the canister more than when the vent cut valve is closed. It means that
This causes deterioration of the adsorption performance of the canister, which is disadvantageous in practical use.

[0012]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention connects the intake passage and the canister of the internal combustion engine by the purge passage, and connects the canister and the fuel tank by the evaporation passage, A rotation speed sensor for detecting an engine rotation speed in an evaporative emission gas control system for opening and closing a vent cut valve disposed in the middle of the evaporation passage by a switch portion that opens and closes in response to opening and closing of a lid of a fuel supply port of a fuel tank. A vehicle speed sensor for detecting the vehicle speed is provided, and a warning means is provided to warn of an abnormal condition.A detection signal from these sensors is input and an opening / closing signal of the switch portion is input to open the lid portion during traveling. If the cover is open, a control means for outputting a control signal to the warning means is provided to warn that the lid is open. And butterflies.

[0013]

According to the invention as described above, when the lid of the fuel supply port of the fuel tank is opened during traveling,
The control means outputs a control signal to the warning means to warn that the lid is in the open state during traveling.

[0014]

Embodiments of the present invention will be described in detail below with reference to the drawings.

1 to 5 show an embodiment of the present invention. In FIG. 2, 2 is a failure diagnostic device for the evaporative emission control system, 4 is a canister, and 6 is a fuel tank.

The canister 4 is provided so as to communicate with an intake passage of an internal combustion engine (not shown), that is, an intake system by a purge passage 8, and a fuel tank is provided with a large-diameter first evaporation passage 10 and a small-diameter second evaporation passage 12. I have contacted 6.

An atmosphere passage 14 for opening to the atmosphere is provided in the canister 4, and an opening / closing valve 16 and an air filter 18 are provided in the atmosphere passage 14 from the canister 4 side.

A vent cut valve 20 is provided in the middle of the large-diameter first evaporation passage 10, and the vent cut valve 2 is provided.
0 is provided with a battery 24 connected via a switch unit 22 to open / close the vent cut valve 20.

The fuel supply port 26 of the fuel tank 6 is provided with a lid part 28 for opening and closing the fuel supply port 26, and the opening / closing operation of the lid part 28 is linked to the opening / closing operation of the switch part 22. That is, by opening the lid portion 28, the switch portion 22 is closed and the vent cut valve 2 is opened.
0 is released.

A rotation speed sensor (not shown) for detecting the engine rotation speed N _E is provided, and a vehicle speed sensor (not shown) for detecting the vehicle speed is provided. The detection signals from these sensors are input and the opening / closing signal of the switch section 22 is inputted. A control means (ECU) 30 for inputting is input.

The control means 30 controls the lid portion 2 during traveling.
When 8 is opened, the lid 28 has a configuration to output a control signal to the warning means 32 to warn of an abnormal state in which the lid 28 is in an open state.

More specifically, the control means 30 is connected to detect the open / closed state of the vent cut valve 20, and the open / close signal of the switch section 22 can be input according to the open / closed state of the vent cut valve 20. , And the open state of the lid portion 28 with which the switch portion 22 is interlocked can be detected.

Therefore, the control means 30 controls the warning means 32, for example, the warning lamp 34, to be turned on when the vehicle is traveling and the lid portion 28 is opened.

Further, a first float rollover valve 36 is provided at the fuel tank side opening portion of the first evaporation passage 10, and a second float rollover valve 38 is provided at the fuel tank side opening portion of the second evaporation passage 12. Set up.

Next, the operation will be described with reference to the control flowchart of the failure diagnostic device 2 of the evaporative emission control system in FIG.

When the control program of the failure diagnosing device 2 of the evaporative emission control system is started (100), the switch section 22 interlocking with the lid section 28 of the fuel supply port 26 judges the open / closed state (102).

When the switch 22 is in the open state in this determination (102), the vent cut valve 20 is closed (CLOSE) (10).
4) If the switch unit 22 is in the closed state in the determination (102), the engine speed N
_{The process} shifts to the determination of _E and the vehicle speed (106), and at the same time, the vent cut valve 20 is opened (OPEN) (108).

The judgment (106) is to confirm whether or not the vehicle is in a stopped state, and the judgment (106) is YES,
That is, when the engine speed N _E is less than the set engine speed N _E1 and the vehicle speed is substantially equal to 0 (zero), it is determined that the vehicle is stopped, and the warning lamp 34 is turned off (11
0), judgment (106) is NO, that is, engine speed N
_If at least one of _E and vehicle speed does not satisfy the condition, it is determined that the vehicle is in a running state, and the warning light 34 is turned on (112).

The flow chart of each state of the vehicle will be described. When the vehicle is running or is stopped, FIG.
As shown in, the lid portion 28 is in the closed state (200) and the switch portion 22 is in the open state (202). The open state of the switch unit 22 indicates the control means (ECU).
It is output to (204), the vent cut valve 20 is closed (206), and the control means (204) turns off the warning light 34 (208).

At the time of refueling, as shown in FIG. 4, the lid portion 28 is in the open state (300) and the switch portion 22 is in the closed state (302). Then, the closed state of the switch portion 22 is output to the control means (ECU) (304) and the vent cut valve 20 is opened (30
6) The control means (204) inputs the detection signal (308) of the engine speed and the vehicle speed, confirms that the vehicle is stopped, and turns off the warning lamp (310).

Furthermore, if the user forgets to tighten the lid while the vehicle is traveling, the lid 28 is in the open state (40
0), and the switch unit 22 is in the closed state (40
2). Then, the closed state of the switch unit 22 is output to the control means (ECU) (404), the vent cut valve 20 is opened (406), and the control means (404) detects the engine speed and the vehicle speed. (4
08) is input to confirm that the vehicle is traveling, and the warning lamp 34 is turned on (410).

As a result, the rotational speed sensor (not shown) can reliably determine whether the internal combustion engine is driven or not, and the vehicle speed sensor (not shown) reliably determines whether or not the vehicle is traveling. It is possible.

Further, by providing the warning means 32, it is possible to reliably warn the driver of an abnormal time, and the abnormal condition can be dealt with swiftly, which is practically advantageous.

Further, a warning light 34 is provided as the warning means 32.
By providing the above, the warning lamp 34 can be turned on in the event of an abnormality to reliably warn the driver.

Furthermore, by providing the control means 30, it is possible to detect the open state of the lid portion 28, and it is possible to reliably prevent forgetting to close the lid portion except when refueling.

Further, when the lid portion 28 is opened when the vehicle is traveling, the vent cut valve 20 remains open. However, a warning from the warning means 32 enables quick response to an abnormal state. Therefore, the amount of the evaporated gas adsorbed on the canister 4 can be reduced.

The present invention is not limited to the above-mentioned embodiment, but various application modifications are possible.

For example, in the embodiment of the present invention, the warning light is used as the warning means. However, a warning buzzer can be used instead of the warning light, and the warning buzzer sounds when there is an abnormality to notify the driver. Can warn. Alternatively, if both the warning light and the warning buzzer are provided and a warning light and a warning buzzer are used to warn when an abnormality occurs,
It becomes possible to issue a more reliable warning.

[0039]

As described in detail above, according to the present invention, the evaporative emission control system is provided with a rotation speed sensor for detecting the engine rotation speed, a vehicle speed sensor for detecting the vehicle speed, and a warning means for warning in the event of an abnormality. Control signal to the warning means to warn that the lid is in the open state when the detection signal from these sensors is input and the opening / closing signal of the switch is input and the lid is opened during traveling. Since the control means for outputting is provided, the rotation speed sensor can reliably determine whether the internal combustion engine is driven or not, and the vehicle speed sensor reliably determines whether or not the vehicle is traveling. It is possible. Further, by providing the warning means, it is possible to reliably warn the driver of an abnormal time, and it is possible to quickly deal with the abnormal condition, which is practically advantageous. Further, if a warning lamp is provided as the warning means, the warning lamp can be turned on in the event of an abnormality to reliably warn the driver. Furthermore, by providing the control means, it is possible to detect the open state of the lid portion, and it is possible to reliably prevent forgetting to close the lid portion other than during refueling. Also, when the lid is open when the vehicle is running, the vent cut valve remains open. However, the warning from the warning means enables quick response to the abnormal condition, and the canister 4 is activated. It is possible to reduce the adsorption amount of the evaporative gas.

[Brief description of drawings]

FIG. 1 is a control flow chart of a failure diagnostic device for an evaporative emission control system showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a failure diagnostic device for an evaporative emission control system.

FIG. 3 is a flowchart when the lid is closed when the vehicle is traveling or is stopped.

FIG. 4 is a flowchart in a refueling state.

FIG. 5 is a flowchart when the lid is released while the vehicle is traveling.

FIG. 6 is a schematic configuration diagram of a failure diagnostic device for an evaporative emission control system showing a conventional technique of the present invention.

[Explanation of symbols]

 2 Failure diagnosis device for evaporative emission control system 4 Canister 6 Fuel tank 8 Purge passage 10 First evaporative passage 12 Second evaporative passage 14 Atmospheric passage 16 Open / close valve 18 Air filter 20 Vent cut valve 22 Switch part 24 Battery 26 Fuel supply port 28 Lid 30 Control means (ECU) 32 Warning means 34 Warning light

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[Procedure amendment]

[Submission date] November 7, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

FIG.

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 5]

[Figure 6]

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area F02B 77/08 K

Claims (1)

[Claims] 1. A switch that connects an intake passage of an internal combustion engine and a canister by a purge passage, connects the canister and a fuel tank by an evaporation passage, and opens and closes according to opening and closing of a lid of a fuel supply port of the fuel tank. In the evaporative gas control system that opens and closes the vent cut valve disposed in the middle of the evaporation passage by a part, a rotation speed sensor for detecting the engine speed and a vehicle speed sensor for detecting the vehicle speed are provided, and a warning is issued to warn of an abnormality. Means for inputting the detection signals from these sensors and inputting the opening / closing signal of the switch portion to warn that the lid portion is in the open state when the lid portion is opened during traveling. A failure diagnosis device for an evaporative emission control system, characterized in that the means is provided with a control means for outputting a control signal.