JPH065058B2 - Evaporative fuel control device for engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an evaporated fuel control device for an engine.

(Prior Art) Conventionally, it is not desirable to directly release evaporated fuel generated in a fuel tank into the atmosphere from the viewpoint of preventing air pollution. Therefore, in order to prevent it, the upper space of the fuel tank is adsorbed inside. The vaporized fuel is temporarily held in the reservoir by communicating with the vaporized fuel reservoir having the agent, and when the throttle valve becomes a certain opening or more during engine operation, the vaporized fuel is supplied to the intake passage and burned. There is known an evaporative fuel treatment apparatus for an engine (see, for example, Japanese Utility Model Laid-Open No. 54-54721).

In such a device, purging is performed regardless of before and after refueling, so a large amount of vaporized fuel stored in the evaporative combustion reservoir during refueling is purged in large amounts during running immediately after refueling, which causes over There is a problem of deterioration of driving performance due to rich.

(Object of the Invention) An object of the present invention is to provide an evaporated fuel control device for an engine, which prevents deterioration of travelability due to overrich due to a large amount of evaporated fuel stored in an evaporated fuel reservoir when fuel is supplied to a fuel tank. And

(Structure of the Invention) The present invention includes an evaporative fuel reservoir that has an adsorbent therein and stores evaporative fuel generated in a fuel tank, and the evaporative fuel reservoir and the intake passage are connected by a purge passage. The present invention relates to an evaporated fuel device of an engine.

In order to achieve the above object, the present invention provides a passage area varying means that is provided in the purge passage and that changes the passage area, a refueling detecting means that detects refueling to a fuel tank, and an output of the refueling detecting means. When the amount that correlates to the operating time after receiving fuel is less than or equal to the set value, the passage area varying means reduces the passage area of the purge passage. And a purge amount control means for increasing the above.

(Example) Hereinafter, the Example of this invention is described along drawing.

In FIG. 1 showing the overall structure of an evaporated fuel control device for an engine, reference numeral 1 is an engine, and an intake passage 2 thereof is in the middle,
It branches into first and second passages 4 and 5, and first and second throttle valves 6 and 7 are arranged in the passages 4 and 5, respectively.
The first throttle valve 6 is linked to an accelerator pedal (not shown), and the second throttle valve 7 is adapted to open when the first throttle valve 6 opens above a certain opening. 8 is an air cleaner.

Reference numeral 9 denotes a fuel tank, the upper space 9a of which is connected to the intake passage 2 downstream of the throttle valves 6 and 7 via an evaporated fuel reservoir 10 having an adsorbent therein. That is,
The upper space 9a is connected to the reservoir 10 via an evaporated fuel passage 12 having a check valve 11,
Are connected to the intake passage 2 via a purge passage 14 having an orifice 13. In the purge passage 14, a bypass passage 15 is provided in parallel with the portion where the orifice 13 is provided, and an electromagnetic opening / closing valve 16 is provided in the middle of the bypass passage 15 (passage area varying means).

A purge control valve 17 is provided at an upstream end of the purge passage 14, that is, a connection portion with the reservoir 10, and a purge control valve 17 is provided via a negative pressure passage 18 when the second throttle valve 7 is opened more than a set opening degree. Negative pressure is introduced and the purge control valve 17 is opened. As a result, the vaporized fuel stored in the reservoir 10 is purged only when the second throttle valve 7 has a load equal to or more than the set opening and equal to or more than the set load.

The electromagnetic opening / closing valve 16 is linked to the fuel supply detection switch 20 via a control circuit 19 as a purge amount control means.
It is about to close for a predetermined time after refueling.

As shown in FIG. 2, the control circuit 19 controls the battery 22 during normal operation when the ignition switch 21 is on.
Is connected to the base of the transistor 24 via the variable resistor 23, and the transistor 24 becomes conductive to excite the relay 25 and open the electromagnetic opening / closing valve 16. On the other hand, when refueling, the third
As shown in the figure, the ignition switch 21 opens,
Since the fuel supply detection switch 20 is closed, the electromagnetic opening / closing valve 16 is closed and the capacitor 27 is discharged. Then, when refueling is completed, the refueling detection switch 20 opens and the ignition switch 21 closes. Therefore, when traveling immediately after refueling,
The capacitor 27 is charged, but it takes a predetermined time to charge it, and during that time, the base of the transistor 24 is not energized, and the electromagnetic on-off valve 16 remains closed to perform the purge through the orifice 13 only. Becomes smaller. Therefore, the purge of evaporated fuel is limited for a predetermined time immediately after refueling, and a large amount is purged immediately after refueling.
There is no risk of overrich. After the completion of charging the capacitor 27, the transistor 24 becomes conductive and the electromagnetic opening / closing valve 16 is opened, so that the purge is performed through the orifice 13 and the bypass passage 15, and the normal operation state in which the passage area becomes large is obtained.

Since the resistance value of the variable resistor 23 varies depending on the throttle opening of the first throttle valve 6, the amount of current flowing through the capacitor 27 changes accordingly, and the time required to charge the capacitor 27, that is, the purge immediately after refueling, is performed. The predetermined time when the passage area of the passage 14 becomes small is corrected.
That is, when the vehicle is traveling with the throttle valve 6 having a large opening degree, the intake amount is large and the purge amount is large. Therefore, even if the time is short, overrich due to refueling may occur. At the same time, the resistance value of the variable resistor 23 is reduced to shorten the above time,
When the vehicle is running with the throttle opening of the throttle valve 6 small, the intake amount is small and the purge amount is small. Therefore, the above time needs to be relatively long, and the resistance value of the variable resistor 23 must be increased. I am trying to lengthen the above time. Therefore, the state in which the passage area of the purge passage 14 is small, that is, the predetermined time immediately after refueling, which is purged only through the orifice 13, is an amount that correlates with the operating time after refueling.

As a result, when the amount that correlates to the operation time after refueling is less than or equal to the set value (the capacitor 27 is charging), the electromagnetic opening / closing valve 16 is closed and the purge is performed only through the orifice 13, and the area of the purge passage is small. On the other hand, when the amount exceeds the set value (after the charging of the capacitor 27 is completed), the electromagnetic opening / closing valve 16 is opened to perform the purge through the orifice 13 and the bypass passage 15, and the area of the purge passage increases.

The refueling detection switch 20 is connected to the refueling port 9 of the fuel tank 9.
The open / close state of the cap member 30 detachably attached to the b is detected. As shown in FIG. 4, the fuel filler port 9b is fixed to the side portion of the portion protruding from the vehicle body 31. In addition,
The cap member 30 is formed with a flange portion 30a for turning on and off the fuel supply detection switch 20.

Further, as shown in FIG. 5, a rubber annular sheet material 35 is provided in the vicinity of the opening of the refueling port 9b, and an opening / closing valve 36 is provided inward of the refueling port 9b. Insert the gun 37 into the fuel filler port 9b to insert the hook member 3
8 is locked to the flange portion 9c of the fuel filler port 9b, the fuel gun 37 abuts the seal member 35 to maintain hermeticity,
Since the opening / closing valve 36 is opened at the tip of the refueling gun 37 to allow refueling, the refueling detection switch 39 is opened / closed.
It may be provided on the lower side of the valve and turned on / off by the opening / closing valve 36.

In the above embodiment, the driving time corrected in accordance with the load state is used as the amount correlated with the driving time, but the traveling distance may be used.

(Effects of the Invention) As described above, according to the present invention, since the passage area of the purge passage is made small immediately after refueling, a large amount of evaporated fuel stored in the reservoir during refueling is purged immediately after refueling. As a result, the deterioration of traveling performance due to overrich can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings show an embodiment of the present invention, and FIG. 1 is an overall configuration diagram of an evaporated fuel control device for an engine, and FIG.
FIG. 3 is an electric circuit diagram of the control circuit, FIG. 3 is a view showing opening / closing timings of an ignition switch, a fuel supply detection switch, and an electromagnetic opening / closing valve, and FIGS. 4 and 5 are explanatory views of the fuel supply detection switch. 1 ... Engine, 2 ... Intake passage, 3 ... Fuel tank,
10 ... Evaporative fuel reservoir, 14 ... Purge passage, 15 ...
Bypass passage, 16 ... Electromagnetic on-off valve, 19 ... Control circuit, 20, 39 ... Refueling detection switch.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaki Komagane 3-1, Shinchi Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (72) Inventor Go Tsujida 3-3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Corporation Within

Claims (1)

[Claims] 1. An engine having an evaporative fuel reservoir having an adsorbent therein and storing evaporative fuel generated in a fuel tank, wherein the evaporative fuel reservoir and an intake passage are connected by a purge passage, A passage area variable means provided in the purge passage for changing the passage area, a refueling detection means for detecting the supply to the fuel tank, and an amount correlating with the operation time after refueling receiving the output of the refueling detection means When the value is less than or equal to the value, the passage area varying means reduces the passage area of the purge passage, and when the value is equal to or more than the set value, the passage area varying means increases the passage area of the purge passage. A fuel vapor control system for an engine, characterized by: