JPH10311255A - Evaporated fuel transpiration preventing device and fuel feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaporated fuel transpiration preventing device to suppress worsening of exhaust gas during the starting of an internal combustion engine without worsening startability of an internal combustion engine owing to the air-fuel ratio of an internal combustion engine brought into a lean state. SOLUTION: First and second canisters 21 and 22 to adsorb evaporated fuel volatized in a fuel tank 2 and a purge pump to effect forced feed of evaporated fuel are arranged in the middle of an evaporation piping to intercommunicate a fuel tank 2 and the suction port of the intake pipe 5 an engine E. A first purge passage to intercommunicate the outlet of the first canister 21 and the suction port of an intake pipe 5 and a canister switching valve 23 to switch the outlet of the second canister 22 and the intake port of the intake pipe 5 are provided. When, during the starting of the engine E, an integrated amount of evaporated fuel in the second canister 22 exceeds a set integrated amount, the canister switching valve 23 is brought into an ON-state and effects switching to the second purge passage and evaporated fuel in the second canister 22 is introduced in the suction port of the intake pipe 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply system for supplying fuel to an internal combustion engine, and more particularly, to a fuel supply system in which fuel vapor adsorbed in a canister is introduced into the internal combustion engine when the internal combustion engine is started. The present invention relates to a fuel evaporation prevention device.

[0002]

2. Description of the Related Art Conventionally, in an automobile such as a car equipped with a gasoline engine using a highly volatile oil (for example, fuel such as gasoline), evaporated fuel (also referred to as evaporative gas or vapor) volatilized in a fuel tank is discharged to the atmosphere. In order to prevent the fuel from being released into the vehicle, it is required to mount a fuel evaporation prevention device (also referred to as a fuel evaporative emission control device or an evaporation system) on the vehicle.

[0003] The fuel evaporation prevention device includes a canister that adsorbs evaporated fuel volatilized in a fuel tank and an evaporative pipe that connects an intake pipe of the internal combustion engine to the canister.
A purge control valve that opens and closes according to the operating state of the internal combustion engine. When the purge control valve is opened, the evaporated fuel adsorbed in the canister is introduced (purged) into the intake pipe of the internal combustion engine by the intake pipe negative pressure and mixed with the air mixed with the fuel, thereby evaporating the evaporated fuel. Has been prevented.

On the other hand, a fuel injection valve (injector) for electronically controlling fuel injection is attached to an intake pipe of an internal combustion engine. The fuel injection valve is configured to inject liquid fuel into the intake pipe in a metered amount according to an injection signal from the engine ECU. The engine ECU determines an optimal amount of injected fuel (hereinafter abbreviated as an injection amount) according to the running state of the vehicle, and the injection amount supplied to the internal combustion engine is controlled by the injection time of the fuel injection valve.

[0005]

By the way, generally,
In a car, when the internal combustion engine starts from a cold state,
The engine ECU increases the injection amount supplied to the internal combustion engine by setting the injection time of the fuel injection valve longer than the injection time after starting the internal combustion engine. This is mainly due to deterioration of atomization of the liquid fuel due to a low temperature of a portion where the liquid fuel injected from the fuel injection valve adheres. However,
Increasing the injection amount supplied to the internal combustion engine means that the liquid fuel that does not contribute to the combustion of the internal combustion engine also increases, and the exhaust gas deteriorates. In particular, there is a problem that hydrocarbon (HC) is increased in the exhaust gas.

Therefore, when the internal combustion engine is started, the fuel vapor adsorbed in the canister of the fuel evaporation prevention device is introduced into the internal combustion engine to prevent the fuel economy from deteriorating due to an increase in the fuel consumption rate and to reduce the HC consumption. It is conceivable to reduce emissions. However, the evaporated fuel in the canister is purged into the intake pipe of the internal combustion engine by the intake pipe negative pressure every time the purge control valve is opened. For this reason, when starting the internal combustion engine, a sufficient amount of evaporated fuel is not always stored in the canister.

Therefore, when starting the internal combustion engine, it is not possible to introduce a sufficient flow rate (purge amount) of evaporated fuel into the internal combustion engine to compensate for the injection amount at the time of starting. There is a possibility that the air sucked from the air hole of the canister is also supplied to the internal combustion engine. Also, when the internal combustion engine is started, the intake pipe negative pressure is not sufficiently generated, so that the fuel vapor cannot be sufficiently supplied to the internal combustion engine. As a result, the air-fuel ratio directly related to the combustion of the internal combustion engine is made leaner (lean) than the target air-fuel ratio, thereby deteriorating the startability of the internal combustion engine. There is a possibility that it will lead to a malfunction that it will not start.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to suppress the deterioration of the exhaust gas at the time of starting the internal combustion engine without causing the deterioration of the startability of the internal combustion engine due to the leaning of the air-fuel ratio of the internal combustion engine. An object of the present invention is to provide an evaporative fuel evaporation prevention device and a fuel supply device. Another object of the present invention is to provide a fuel supply device capable of preventing fuel economy from deteriorating at the time of starting the internal combustion engine.

[0009]

Means for Solving the Problems Claim 1 or Claim 9
According to the invention described in (1), the evaporated fuel volatilized in the fuel tank is adsorbed in the first canister and also adsorbed in the second canister. After the start of the internal combustion engine, the evaporated fuel adsorbed in the first canister is desorbed and introduced into the intake side of the internal combustion engine through the first purge passage. This can prevent the fuel vapor from being directly released into the atmosphere. At this time, fuel vapor is accumulated in the second canister.

When the internal combustion engine is started, the fuel vapor stored in the second canister is desorbed and introduced into the intake side of the internal combustion engine through the second purge passage. Thereby, the evaporated fuel at a flow rate corresponding to the injection amount at the start of the internal combustion engine can be introduced into the intake side of the internal combustion engine. Therefore, even when the internal combustion engine is started from a cold state,
By introducing the vaporized fuel originally vaporized to the intake side of the internal combustion engine, it is possible to suppress an increase in liquid fuel that does not contribute to the combustion of the internal combustion engine, thereby suppressing deterioration of exhaust gas. Furthermore, since the internal combustion engine can be started even when the injection amount of the liquid fuel from the fuel injection valve is reduced or the injection is stopped when the internal combustion engine is started, the fuel economy can be improved by reducing the fuel consumption rate. Can be.

According to the second or tenth aspect of the present invention, by providing the purge pump in the middle of the second purge passage, even if the internal combustion engine having a small intake pipe negative pressure is started, the second purge passage can be started. The fuel vapor accumulated in the two canisters can be forcibly introduced into the intake side of the internal combustion engine. According to the third or eleventh aspect of the present invention, the first canister adsorbs the evaporated fuel via the second canister. That is, the evaporated fuel is preferentially adsorbed to the second canister. Thereby, the evaporated fuel sufficient for starting the internal combustion engine can be more reliably adsorbed in the second canister. According to the fourth or twelfth aspect of the present invention, there is provided a passage switching unit, which switches and controls the passage switching unit to form a second purge passage by communicating the second switching passage with the communication passage. Alternatively, the first switching passage communicates with the communication passage to form a first purge passage. Accordingly, the communication path for connecting the passage switching means and the intake side of the internal combustion engine can be shared by the first purge passage and the second purge passage, and can be made one. Further, according to the fifth or thirteenth aspect of the present invention, the starting fuel of the internal combustion engine is directly introduced into the intake ports of the respective combustion chambers of the internal combustion engine by introducing the fuel vapor stored in the second canister. Can be improved.

According to the invention described in claim 6 or claim 14, when the desorption characteristic of the evaporated fuel adsorbed in the second canister is reduced, that is, when the temperature is detected by the temperature detecting means. If the temperature around the second canister is lower than the predetermined temperature, the second
The supply of the evaporated fuel from the canister to the intake side of the internal combustion engine is stopped. As a result, when the internal combustion engine is started, the desorption characteristics of the evaporated fuel are poor, and it is not possible to supply the evaporated fuel at a flow rate sufficient to supplement the startup injection amount. Is not introduced into the internal combustion engine. Therefore, by suppressing the air-fuel ratio of the internal combustion engine from becoming leaner than the target air-fuel ratio, it is possible to suppress the deterioration of the startability of the internal combustion engine.

According to the present invention, when the fuel vapor in the second canister is smaller than a predetermined amount, the fuel vapor from the second canister to the intake side of the internal combustion engine is discharged. The supply is stopped. Accordingly, when the fuel vapor is not stored in a sufficient amount to supplement the injection amount at the time of starting, the fuel vapor is not supplied from the second canister to the intake side of the internal combustion engine. This can prevent the startability of the internal combustion engine from deteriorating due to the lean air-fuel ratio of the air-fuel mixture.

More specifically, the fuel tank temperature detected by the tank temperature detecting means and the fuel set by the tank pressure setting means are set as in the invention according to claim 8 or 16. The amount of fuel vapor generated per unit time is calculated from the pressure in the tank. Then, the integrated amount of the evaporated fuel in the second canister is calculated from the calculated amount of the evaporated fuel per unit time, and the integrated amount is set as the amount of the evaporated fuel in the second canister. When the calculated amount of fuel vapor in the second canister is equal to or greater than the set amount when the internal combustion engine is started, a sufficient amount of fuel vapor accumulated in the second canister is introduced to the intake side of the internal combustion engine. I do. Thereby,
At the time of starting the internal combustion engine, it is possible to introduce a sufficient amount of evaporative fuel so as to more reliably supplement the starting injection amount. Note that the injection amount at the start may be entirely supplemented by the evaporated fuel supplied from the second canister to the intake side of the internal combustion engine, or the injection amount at the start from the fuel injection valve may be reduced and compensated by the reduced amount. You may do it.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 to FIG. 7 show a first embodiment of the present invention, and FIG. 1 is a diagram showing a fuel piping system of an automobile such as a car equipped with a gasoline engine.

A fuel supply device 1 of the present embodiment includes a liquid fuel injection device 3 for injecting a liquid fuel (for example, highly volatile fuel such as gasoline) in a fuel tank 2 into a gasoline engine (hereinafter abbreviated as engine) E, An engine E is provided with an evaporative fuel evaporation prevention device 4 for introducing evaporative fuel or the like volatilized in the fuel tank 2.

The engine E is a component corresponding to the internal combustion engine of the present invention, and is mounted in an engine room provided on the front side in the traveling direction of a vehicle such as a vehicle equipped with a gasoline engine. A throttle valve 6 that opens and closes in conjunction with an accelerator pedal (not shown) is provided in an intake pipe (intake manifold) 5 of the engine E. The intake pipe 5 of the engine E is connected to a combustion chamber (not shown) formed between a cylinder and a piston of the engine E. Further, the combustion chamber is connected to an exhaust pipe 7 for discharging exhaust gas.

First, the fuel tank 2 of the embodiment will be briefly described with reference to FIG. The fuel tank 2 is mounted between a cabin of a car and a trunk room. On the side of the fuel tank 2, a tubular filler neck 8 forming a fuel supply passage for supplying liquid fuel therein is provided so as to extend obliquely upward. A filler cap 9 is attached to the tip of the filler neck 8. Further, a purge hole for adsorbing the evaporated fuel volatilized in the fuel tank 2 to the evaporated fuel evaporation preventing device 4 is formed in a ceiling portion of the fuel tank 2.

Next, the liquid fuel injection device 3 of the present embodiment will be briefly described with reference to FIG. This liquid fuel injection device 3
A fuel pump 11 for pressurizing and supplying liquid fuel in the fuel tank 2, a fuel branch pipe 12 provided in the intake pipe 5 of the engine E, and a plurality of fuel injection valves ( The fuel pump 11 and each fuel injection valve 13 are constituted by an engine control device (hereinafter referred to as an engine ECU) shown in FIG. ) 50 electronically controlled.

The fuel pump 11 sucks liquid fuel from the fuel tank 2 and sends it to the fuel branch pipe 12 under pressure, and is accommodated in the fuel tank 2. Also, the fuel branch pipe 12
Is for distributing the liquid fuel pumped from the fuel pump 11 to each fuel injection valve 13. The fuel injection valve 13 is housed in the fuel branch pipe 12 attached to the intake pipe 5 and sprays liquid fuel into each intake port of the intake pipe 5 of the engine E based on an injection signal from the engine ECU 50. Atomize and spray. The fuel branch pipe 12 is provided with a pressure regulating valve 15.
The pressure of the liquid fuel inside is regulated to a predetermined pressure by the pressure regulating valve 15. Excess liquid fuel during pressure regulation is returned to the fuel tank 2 through the return pipe 16.

Next, the evaporative fuel evaporation prevention device 4 of this embodiment
Will be briefly described with reference to FIG. The evaporative fuel evaporation prevention device 4 includes an evaporative pipe connecting each suction port of the intake pipe 5 of the engine E and a purge hole of the fuel tank 2, and a first and a second canister 2 provided in the middle of the evaporative pipe.
1, 22, a canister switching valve 23 for switching a purge passage, which will be described later, and the intake pipe 5 and the first and second canisters 2.
Each of the components of the evaporative fuel piping system such as the evaporative fuel pumping mechanism 24 provided in the middle of the evaporative piping between the first and second evaporative pipings.

A canister communication passage 25 communicating the purge hole of the fuel tank 2 with the inlet of the first canister 21 and a first switching passage 26 communicating the outlet of the first canister 21 with the canister switching valve 23 are connected to the evaporation pipe. A second switching passage 27 that communicates the outlet of the second canister 22 with the canister switching valve 23 and a communication passage 42 that communicates the canister switching valve 23 with each suction port of the intake pipe 5 are formed. In the middle of the canister communication passage 25, a second canister 22 is provided. And the first and second switching passages 2
6 and 27 are formed so as to follow the same passage from the canister switching valve 23.

The first canister 21 contains an adsorbent (not shown), such as activated carbon, for adsorbing fuel vapor. Thereby, the first canister 21 can adsorb the evaporated fuel volatilized in the fuel tank 2 through the second canister 22. Further, the first canister 21 is formed with an atmospheric hole 28 opened to the atmosphere, so that air can be sucked into the inside. The air hole 28 is provided with a canister control valve (canister control valve) 29 for closing the air hole 28 as required. The canister control valve 29 is an electromagnetic on-off valve that closes when energized.

The second canister 22 is a start-only canister for introducing evaporated fuel into the intake port of the intake pipe 5 when the engine E is started. This second canister 22
In the same manner as in the first canister 21, an adsorbent (not shown) made of, for example, activated carbon for adsorbing fuel vapor is stored. Thereby, the second canister 22 can adsorb the evaporated fuel volatilized in the fuel tank 2.
Then, after the fuel in the second canister 22 becomes full (for example, about 10 g), the fuel in the first canister 21 is adsorbed.

The canister switching valve 23 is a component corresponding to the passage switching means of the present invention, and includes the communication passage 42 and the first switching passage 2.
6 is a solenoid-operated two-position switching valve that switches between a first purge passage composed of a second purge passage and a second purge passage composed of a communication passage and a second switching passage 27. After the engine E is started (when the energization is stopped), the canister switching valve 23 communicates with the first canister 21 and the intake pipe 5 through the first purge passage.
It is set on the side that connects the suction port. Further, the canister switching valve 23 is set on the side connecting the second canister 22 and the suction port of the intake pipe 5 via the second purge passage during the start of the engine E (when energized).

Next, the evaporated fuel pumping mechanism 24 will be described with reference to FIGS. Here, FIG. 2 is a diagram showing the evaporated fuel pumping mechanism 24. The evaporative fuel pumping mechanism 24
Is a fuel-driven purge pump 30 that forcibly pumps the evaporated fuel in the first and second canisters 21 and 22 to the intake pipe 5 of the engine E, and adjusts the flow rate of the liquid fuel that drives the purge pump 30. Bypass valve (bypass valve) 3
1, and a purge control valve (purge control valve) 32 for adjusting the purge flow rate of the evaporated fuel supplied (purged) to the intake pipe 5 of the engine E via the evaporation pipe. The above-mentioned canister switching valve 23, canister control valve 29, bypass valve 31, and purge control valve 32 are connected to a purge control device (hereinafter, referred to as a purge ECU) 60 connected to the engine ECU 50 via a communication line.
Is controlled by

The purge pump 30 is provided in a fuel pipe 33 and has a Berton turbine 34 whose rotation speed changes according to the flow rate of liquid fuel, and a magnetic coupling (not shown) to a rotating shaft 35 of the Berton turbine 34. And a pump body 36 with a built-in turbine (not shown) connected thereto via a pump. In the fuel pipe 33, an auxiliary fuel passage 37 communicating with the main fuel passage 14 is formed on the upstream side and the downstream side. The inlet pipe 38 integrally formed with the pump body 36 is provided with the canister switching valve 2.
3 are connected to the outlets of the first and second canisters 21 and 22. In addition, first and second purge passages (communication passages 42) are formed in the inlet pipe 38.

The bypass valve 31 supplies the liquid fuel flowing through the auxiliary fuel passage 37 to the Belton turbine 34 of the purge pump 30.
It is provided in the middle of a bypass passage 39 that detours from the (fuel pipe 33). The bypass valve 31 is an electromagnetic proportional control valve that adjusts the passage resistance of the bypass passage 39 by changing the opening area of the bypass passage 39 according to the amount of electricity. Thus, as the bypass valve 31 reduces the opening area of the bypass passage 39, the flow rate of the liquid fuel flowing into the fuel pipe 33 increases, so that the discharge amount of the evaporated fuel from the purge pump 30 increases. Conversely, as the bypass valve 31 increases the opening area of the bypass passage 39, the flow rate of the liquid fuel flowing into the fuel pipe 33 decreases, so that the discharge amount of the evaporated fuel from the purge pump 30 decreases.

Accordingly, by controlling the amount of current supplied to the bypass valve 31 by the purge ECU 60, the amount of fuel vapor discharged from the purge pump 30 can be adjusted. For example, when the power supply to the bypass valve 31 is stopped (turned off), the bypass valve 31 is closed, so that the discharge amount of the fuel vapor from the purge pump 30 becomes the maximum discharge amount (for example, 40 l / min.
60 l / min). Further, when the bypass valve 31 is energized (turned on), the bypass valve 31 is opened, so that the discharge amount of the fuel vapor from the purge pump 30 becomes the minimum discharge amount (for example, 0 l / min to 10 l / min). Become.

The purge control valve 32 is provided in a first pipe 40 formed in an outlet pipe 40 of a pump body 36 of the purge pump 30.
The second purge passage (communication passage 42) is provided to open and close. The purge control valve 32 changes the purge flow rate of the evaporated fuel supplied to the intake pipe 5 of the engine E based on the duty ratio between the valve opening time (ON time) and the valve closing time (OFF time). It is. The purge control valve 32 is an electromagnetic on-off valve that opens when energized. Thus, when the purge control for supplying the evaporated fuel adsorbed by the adsorbents in the first and second canisters 21 and 22 to the engine E is stopped, the purge control valve 32 may be closed. Here, of the above configurations, the canister switching valve 23, the evaporative fuel pumping mechanism 24, the first switching passage 26, the second
The switching passage 27, the communication passage 42, and the purge ECU 60 shown in FIG. 3 correspond to a purge control unit of the present invention.

Next, the engine ECU 50 and the purge E
The CU 60 will be described with reference to FIGS. Here, FIG. 3 is a diagram showing a control system of the fuel supply device 1.
The engine ECU 50 corresponds to the fuel injection control means of the present invention, and is itself a microcomputer for an engine control system for controlling the engine E having a built-in CPU, ROM, RAM and a timer circuit. The engine ECU 50 includes an engine speed sensor 51, a vehicle speed sensor 52, a throttle opening sensor 53,
A signal for notifying the operating state of the engine E including a cooling water temperature sensor 54, an intake air temperature sensor 55, an intake air amount sensor 56, an oxygen sensor 57, and the like, and a signal from the purge ECU 60 are input.

The engine ECU 50 controls the idle speed of the engine E based on a sensor signal input from each sensor, a communication signal received from the purge ECU 60, and a control program previously stored in the ROM.
The ECU performs engine control such as fuel injection amount control, fuel injection timing control, intake throttle control, air-fuel ratio feedback control, and ignition timing control, and transmits signals necessary for control processing of the purge ECU 60 to the purge ECU 60. Further, when the engine E is started, the engine ECU 50
When a later-described evaporative injection non-execution signal is transmitted from 60, the well-known start-up injection control is executed, and after the start-up, the well-known post-startup injection control is executed.

The engine speed sensor 51 is a speed detecting means for detecting the speed of the crankshaft of the engine E. The vehicle speed sensor 52 is, for example, a reed switch type vehicle speed sensor, a photoelectric type vehicle speed sensor, an MRE (magnetic resistance element) type vehicle speed sensor, or the like, and is a vehicle speed detecting means for detecting the speed of the vehicle. The throttle opening sensor 53 is a throttle opening detecting means for detecting the opening of the throttle valve 6 disposed in the intake pipe 5 of the engine E. Further, the cooling water temperature sensor 54 is a cooling water temperature detecting means for detecting the temperature of the cooling water for cooling the engine E.

The intake air temperature sensor 55 corresponds to the temperature detecting means of the present invention, and is an intake air temperature detecting means for detecting an intake air temperature of air taken into the intake pipe 5 of the engine E via an air filter. . Note that, instead of the intake air temperature sensor 55, a temperature around the second canister 22 may be detected by using a cooling water temperature sensor 54 or an outside air temperature sensor.

Further, the intake air amount sensor 56 is, for example, an air flow meter or the like, and is an intake air amount detecting means for detecting a flow amount (intake air flow amount) of intake air sucked into the intake pipe 5 of the engine E through an air filter. . The oxygen sensor 57 is an air-fuel ratio detecting unit for air-fuel ratio feedback for detecting the oxygen concentration in the exhaust gas flowing in the exhaust pipe 7 of the engine E. Each of these sensors is also an operating state detecting means for detecting the operating state of the engine E.

The purge ECU 60 itself has a CPU,
This is a microcomputer for a purge control system and a vapor injection timing control system which incorporate a ROM, a RAM and a timer circuit. The purge ECU 60 is supplied with power from a battery 62 when an ignition switch 61 is turned on (turned on), and receives sensor signals input from a tank internal pressure sensor 63 and a tank internal temperature sensor 64 and communication signals received from the engine ECU 50 (for example, the engine E). (A signal indicating the operating state). Then, the purge ECU 60 outputs a sensor signal input from each sensor,
Communication signal received from engine ECU 50 and RO
Based on a control program stored in advance in M, the energization control of the canister switching valve 23, the canister control valve 29, the purge pump 30, the bypass valve 31, the purge control valve 32, and the like is performed.

The tank internal pressure sensor 63 is a tank internal pressure detecting means that is attached to the ceiling of the fuel tank 2 and detects the internal pressure in the fuel tank 2. In addition, the tank internal pressure sensor 63 is connected to the evaporative piping or the first and second canisters 2.
1, 22 may be attached to detect the internal pressure. The in-tank temperature sensor 64 is an in-tank temperature detecting unit that detects the temperature in the fuel tank 2 in order to measure the amount of evaporation (evaporation amount) from the liquid fuel in the fuel tank 2. It should be noted that instead of the tank temperature sensor 64, a temperature detecting means for detecting the temperature around the fuel tank 2 may be provided.

[Purge Control and Evaporative Injection Control of the First Embodiment] Next, purge control and evaporative injection control of the present embodiment will be briefly described with reference to FIGS. Here, FIG. 4 is a flowchart showing the purge control and the evaporative injection control by the purge ECU 60. In addition, the flowchart of FIG.
msec) is executed every time elapses.

First, initialization is performed (step S
1). Next, a sensor signal necessary for the subsequent control processing is read from the engine ECU 50 (step S2). next,
The sensor signals necessary for the subsequent control processing are read from the tank internal pressure sensor 63 and the tank internal temperature sensor 64 (step S3).

Next, it is determined whether or not the engine E is being started. Specifically, it is determined whether the ignition switch 61 is ON and the engine speed (NE) detected by the engine speed sensor 51 is lower than a predetermined speed (NES: 500 rpm, for example) (step S4). ). If the result of this determination is NO, the routine of FIG. 5 is started, purge control / evaporation control after startup is performed (step S5), and control returns to step S2. If the result of the determination in step S4 is YES, the routine of FIG. 7 is started to perform the evaporative injection control at the time of startup (step S6), and returns to the control process of step S2.

[Purge Control / Evaporation Injection Control After Start of First Embodiment] Next, purge control / evaporation injection control after start of this embodiment will be briefly described with reference to FIGS. 5 and 6. FIG. Here, FIG. 5 is a flowchart showing the purge control / evaporation injection control after the start by the purge ECU 60.

If the result of the determination in step S4 is NO, that is, if it is determined that the engine E has been started, the canister switching valve 23 is turned off. This allows
The outlet of the first canister 21 and the suction port of the intake pipe 5 are communicated via the first purge passage including the first switching passage 26 and the communication passage 42 (step S11). Next, the routine of FIG. 6 is started, and normal purge flow rate control is performed (step S12).

Next, the integrated amount (EVPn) of the evaporated fuel (evaporative gas) in the second canister 22 is set to the set integrated amount (E
VPs: for example, 10 g) or more (step S13). If the result of this determination is YES, the set pressure (TPs) of the internal pressure in the fuel tank 2 is set to a high pressure (HI: for example, atmospheric pressure + 20 mmHg) (tank pressure setting means: step S14). As a result, the amount of evaporative fuel volatilized in the fuel tank 2 is reduced. Next, the process proceeds to a control process of step S16.

On the other hand, if the decision result in the step S13 is NO, a set pressure of the internal pressure in the fuel tank 2 (TP
s) is set to a low pressure (LO: for example, a pressure together with the atmospheric pressure) (tank pressure setting means: step S15). As a result, the amount of fuel vapor that evaporates in the fuel tank 2 increases.

Next, the amount of evaporative fuel generated per unit time (EVPg) is calculated based on the following equation (1), and RA
The generation amount (EVPg) of the evaporated fuel stored in M is updated (generation amount calculation means: step S16).

EVPg ← f {(TPs), (TTh)} where TPs is the value of step S14 or step S15.
TTh is the temperature inside the fuel tank 2 detected by the tank temperature sensor 64.

Next, the integrated amount (EVPn) of the evaporated fuel in the second canister 22 is calculated based on the following equation (2), and the integrated amount (EVPn) stored in the RAM is updated (integrated). Quantity calculation means: Step S17).

## EQU2 ## EVPn ← EVPn + EVPg

[Purge Flow Control of the First Embodiment] Next, the purge flow control of the present embodiment will be briefly described with reference to FIG. FIG. 6 is a flowchart showing the purge flow rate control by the purge ECU 60.

First, it is determined whether the purge execution condition is satisfied (step S20). This determination result is NO
In this case, the purge control valve 32 is turned off to stop the purge control / evaporation injection control (step S21). Next, the process exits the flowchart of FIG. Here, the purge execution condition is satisfied, for example, when the throttle opening is large and the vehicle speed is in a high speed range, when the air-fuel ratio feedback control is performed, or when the engine rotation speed is high and the throttle opening is large. This is true when the vehicle is not running under load.

If the decision result in the step S20 is YES, the purge control valve 32 is turned on and the purge pump 30 is operated (ON) (step S22). Next, according to a characteristic diagram (not shown) based on the operating state of the engine E (for example, the intake air temperature detected by the intake air temperature sensor 55),
The required purge flow rate (QPR) of the evaporated fuel introduced into the intake pipe 5
G) is determined (step S23). The required purge flow rate of the evaporated fuel may be calculated according to the throttle opening detected by the throttle opening sensor 53.

Next, a set purge flow rate (QLOW: for example, 5 l / min to 10 l / mi stored in the ROM in advance)
n) and the determined required purge flow rate (QPRG), the required purge flow rate is smaller than the set purge flow rate (Q
It is determined whether or not PRG <QLOW) flow rate (step S24). If the determination result in step S24 is NO, the bypass valve 31 is closed (step S2).
5). As a result, the discharge amount becomes a normal discharge amount (for example, 40
1 / min to 60 1 / min), the purge pump 30 is operated, and the evaporative injection control is executed.

Next, the duty ratio (on / off ratio) of the purge control valve 32 is determined according to the required purge flow rate (normal flow rate determining means: step S26). Next, the on-time and off-time of the purge control valve 32 are controlled so as to achieve the determined duty ratio (step S27). Thereafter, the process exits the flowchart of FIG. Step S
If the determination result at 24 is YES, the bypass valve 31 is opened (step S28). Accordingly, the purge pump 30 is operated so that the discharge amount becomes a low discharge amount (for example, 0 l / min to 10 l / min), and the purge control is executed. Next, the duty ratio (on / off ratio) of the purge control valve 32 is determined according to the required purge flow rate (step S29). Next, the process proceeds to a control process of step S27.

[Evaporation Injection Control at Startup of First Embodiment]
Next, the evaporative emission control at the time of starting according to the present embodiment will be briefly described with reference to FIG. Here, FIG.
5 is a flowchart showing the evaporative injection control at the time of starting according to the embodiment.

If the decision result in the step S4 is YES,
That is, when it is determined that the engine E is started, the temperature environment around the second canister 22 is in a temperature environment in which the desorption characteristics of the fuel vapor in the second canister 22 from the adsorbent deteriorates. It is determined whether or not. For example, it is determined whether the cooling water temperature (THW) detected by the cooling water temperature sensor 54 is equal to or higher than a set cooling water temperature (THWs: for example, −10 ° C.) (second canister temperature detecting means: step S31). If the result of this determination is NO, the canister switching valve 23 is turned off. Thus, the outlet of the first canister 21 and the suction port of the intake pipe 5 are communicated via the first purge passage (Step S32).

Next, the purge control valve 32 is turned off to stop the evaporative injection control (step S33). Next, the start-time evaporative injection non-execution signal is sent to the engine ECU 5 so that the injection amount of the liquid fuel injected from each fuel injection valve 13 is set to the normal start-time injection amount according to the operating state of the engine E.
0 (step S34). For example, the injection amount control according to the operating state of the engine E, that is, the fuel injection valve 1
Communication is performed so as to perform control for setting the injection time of No. 3 to, for example, 0.05 seconds to 0.50 seconds. Thereafter, the process exits the flowchart of FIG.

If the result of the determination in step S31 is YES
In the case of (2), similarly, it is determined whether or not the temperature environment of the second canister 22 is a temperature environment in which the desorption characteristics of the evaporated fuel in the second canister 22 from the adsorbent deteriorate. For example, the intake air temperature (THA) of the engine E detected by the intake air temperature sensor 55 is equal to the set intake air temperature (THAs: for example, -10).
(C) or higher (second canister temperature detecting means: step S35). This determination result is N
In the case of O, the processing shifts to the control processing of step S32.
Step S31 and step S35 may be determined as either one.

If the result of the determination in step S35 is YES
In this case, the integrated amount (EVPn) of the evaporated fuel (evaporative gas) adsorbed in the second canister 22 calculated in step S17 of the flowchart of FIG. 5 is equal to or greater than the set integrated amount (EVPs: for example, 10 g). It is determined whether or not (step S36). If the result of this determination is NO, the process moves to the control process in step S32.

If the result of the determination in step S36 is YES
In this case, the canister switching valve 23 is turned on. As a result, the communication path 42 and the second switching path 27 communicate with each other to form a second purge path (step S37). Next, the bypass valve 31 is closed, the purge control valve 32 is turned on, and the purge pump 30 is operated (step S3).
8).

Next, the injection amount of the liquid fuel injected from each fuel injection valve 13 is measured by the second canister 22 from the engine E.
A start evaporative injection execution signal is transmitted to the engine ECU 50 to notify that the amount of fuel to be reduced is reduced by the amount corresponding to the evaporated fuel supplied to the engine or to cut the injection (step S).
39). For example, communication is performed so as to perform injection amount control according to the operating state of the engine E, that is, control to set the injection time of the fuel injection valve 13 to, for example, 0 seconds to 0.10 seconds.

Next, a predetermined time (for example, 0.5 sec.
It is determined whether or not 2.0 seconds have elapsed (step S40). If this determination result is NO, step S
It returns to the control processing of 40. If the result of the determination in step S40 is YES, the accumulated amount of fuel vapor (EVPn) in the second canister 22 stored in the RAM is reset (step S41). Thereafter, the process exits the flowchart of FIG.

[Operation of First Embodiment] Next, the operation of the fuel supply device 1 of the present embodiment will be briefly described with reference to FIGS.

When the temperature around the fuel tank 2 increases, the liquid fuel in the fuel tank 2 evaporates and moves upward from the fuel tank 2. Then, the evaporated fuel present above the fuel tank 2 flows into the canister communication passage 25 from a purge hole formed in the ceiling portion of the fuel tank 2 and is adsorbed by the adsorbent in the second canister 22 to be adsorbed by the second canister 22. When the fuel in the second canister 22 is full, the fuel is adsorbed by the adsorbent in the first canister 21 and accumulated in the first canister 21.

When the driver turns on the ignition switch 61 to start the engine E, the conditions for executing the evaporative injection control at the time of start are satisfied, and the desorption characteristics of the evaporated fuel in the second canister 22 are determined. . When all the conditions are satisfied, the purge pump 30 starts operating, and the canister switching valve 23 is turned on. Thereby, the outlet of the second canister 22 and the suction port of the intake pipe 5 are communicated via the second purge passage including the second switching passage 27 and the communication passage 42.

Therefore, the fuel vapor adsorbed by the adsorbent in the second canister 22 is desorbed from the adsorbent,
The fuel is forcibly injected into each intake port of the intake pipe 5 of the engine E via the canister switching valve 23, the purge pump 30, and the purge control valve 32. At this time, the amount of fuel injected from each fuel injection valve 13 is reduced by the amount of fuel supplemented by the evaporated fuel supplied from the second canister 22 to the engine E, or the amount of fuel injected from the second canister 22 to the engine E is reduced. Since fuel injection from each fuel injection valve 13 is cut off when sufficient evaporated fuel is supplied to start E, the amount of unburned fuel that has not contributed to combustion in each combustion chamber of the engine E is reduced.

After the engine E starts, the canister switching valve 23 is turned off. As a result, the outlet of the first canister 21 and the intake pipe 5 are connected via the first purge passage.
Is communicated with the suction port. Then, it is determined that the purge / evaporation execution condition is satisfied, and if all the purge / evaporation execution conditions are satisfied, the purge pump 30
Starts operating.

Therefore, the evaporated fuel adsorbed in the first canister 21 is desorbed from the adsorbent by the air that has entered the first canister 21 from the air holes 28, and the canister switching valve 23, the purge pump 30 and the purge It is forcibly introduced into each intake port of the intake pipe 5 of the engine E via the control valve 32. As a result, the release of the evaporated fuel volatilized in the fuel tank 2 to the atmosphere is prevented. At this time, the injection amount of the liquid fuel injected from each fuel injection valve 13 into each intake port of the intake pipe 5 is a normal injection amount according to the operating state of the engine E. The air-fuel ratio in the combustion chamber becomes lean (lean), and the output of the engine E is improved.

[Effects of the First Embodiment] As described above, the fuel supply device 1 of the present embodiment can be used when the integrated amount of the evaporated fuel in the second canister 22 at the start of the engine E is equal to or larger than the set integrated amount. Turns on the canister switching valve 23 to switch to the second purge passage. As a result, when the engine E is started, a sufficient amount of fuel vapor accumulated in the second canister 22 is accumulated in the intake pipe 5 of the engine E.
Is injected into each suction port. As a result, a sufficient amount of fuel to supplement the start-up injection amount of the engine E can be introduced into the intake side of the engine E in a well-atomized state of the evaporated fuel.

Therefore, even when the engine E is started from a cold state, by injecting the vaporized fuel originally vaporized into the intake port of the intake pipe of the engine E, the liquid fuel which does not contribute to the combustion of the engine E can be discharged. Since it can be reduced, HC emissions in the exhaust gas can be reduced. Further, when the engine E is started, the fuel injection valve 13
Since the engine E can be started by supplying the fuel vapor without performing the fuel injection in consideration of the amount of fuel attached to the wall surface of the suction port, the fuel consumption rate is reduced, thereby improving the fuel economy. Can be.

In this embodiment, a canister switching valve 23 having two set positions is provided as a passage switching means for switching between the first purge passage and the second purge passage. Therefore, if the first and second canisters 21 and 22 inject the fuel vapor into the intake port of the intake pipe 5 of the engine E when the engine E is started,
When starting the engine E, it is not possible to supply the evaporated fuel at an accurate flow rate corresponding to the increase in the injection amount.
There is a problem that air in the canister 21 and the fuel tank 2 and also air entering through the atmosphere holes 28 are introduced into the intake port of the intake pipe of the engine E. However, in the present embodiment, the use of the canister switching valve 23 having two setting positions eliminates the above-described problem, and the setting corresponding to the increase in the injection amount accumulated in the second canister 22. Since the integrated amount of evaporated fuel can be introduced into the intake port of the intake pipe of the engine E, it is possible to prevent the air-fuel ratio of the engine E from becoming leaner than the target air-fuel ratio, thereby suppressing the deterioration of the startability of the engine E. Can be.

On the other hand, even when the engine E is started, if the fuel injection condition is not satisfied, the canister switching valve 23 is turned off to switch to the first purge passage. At this time, the injection period of the fuel injection valve 13 is controlled so that the injection amount of the fuel injection valve 13 is larger than the post-start injection amount. As a result, it is possible to suppress the air-fuel ratio of the engine E from becoming leaner than the target air-fuel ratio. Therefore, the startability of the engine E is improved, so that the engine E is reliably exploded and started.

Further, even when the engine E is started, if the desorption characteristics of the evaporated fuel adsorbed by the adsorbent in the second canister 22 are degraded, that is, if the desorption characteristic is detected by the cooling water temperature sensor 54, When the detected cooling water temperature is lower than the set cooling water temperature, or when the intake air temperature detected by the intake air temperature sensor 55 is lower than the set intake air temperature, the canister switching valve 23 is turned off and the first The purge passage is switched to the purge passage, and the purge control valve 32 is closed.

Therefore, when the engine E is started, the second
The desorption characteristic of the evaporated fuel from the adsorbent in the canister 22 is poor, and it is not possible to supply the evaporated fuel at a flow rate corresponding to the increase in the injection amount injected from the fuel injection valve 13. Also, the air in the fuel tank 2 is not introduced into the engine E. Thus, by suppressing the air-fuel ratio of the engine 2 from becoming leaner than the target air-fuel ratio, it is possible to suppress the deterioration of the startability of the engine E.

FIG. 8 shows a second embodiment of the present invention.
FIG. 4 illustrates an embodiment and is a diagram illustrating a control system of a fuel supply device.

The fuel supply device 1 of the present embodiment includes an engine E
The first and second purge passages (communication passages 42) formed in the evaporative piping that communicate the intake pipe 5 with the first and second canisters 21 and 22 vary depending on the amount of electricity (for example, applied voltage). A motor-driven (electric) purge pump (the evaporative fuel according to the present invention) in which the rotation speed of an electric actuator (not shown) such as an electric motor changes the discharge amount of evaporative fuel from the pump body. 41 (corresponding to a pressure feeding means). Here, in this embodiment, since the purge pump 41 of the motor drive type is used, it is not necessary to increase the number of pipes of the fuel pipe system as in the first embodiment. Thus, the number of parts and the number of assembling steps of the fuel supply device 1 and the liquid fuel injection device 3 can be reduced, so that the product price can be reduced.

[Modification] In the first embodiment, the fuel injection valve 1
Although the fuel-driven purge pump 30 driven by the fuel fed to the pump 3 is used, an engine-driven purge pump driven by the engine E may be used. The liquid fuel flowing in the main fuel passage 14 or the fuel branch pipe 12 is replaced with the fuel flowing in the sub fuel passage 37.
The purge pump 30 may be driven by the liquid fuel flowing in the return passage for returning the liquid fuel from the fuel tank 2 to the fuel tank 2.

In the first embodiment, the bypass valve 31 is provided in the bypass passage 39 for diverting the fuel from the purge pump 30. However, the flow rate of the fuel flowing in the auxiliary fuel passage 37 for supplying the fuel to the purge pump 30 is adjusted. A flow control valve may be provided. In the second embodiment, the purge control valve 32 is not provided on the downstream side of the motor-driven purge pump 41. However, as in the first and second embodiments, the purge control valve 32 is provided on the downstream side of the purge pump 41. May be provided.

In this embodiment, the canister switching valve 23 having two set positions is used as the passage switching means. However, as the passage switching means, an electromagnetic on-off valve capable of opening and closing the first and second purge passages respectively. May be used. Further, not only the electromagnetic valve but also a switching valve for mechanically switching the first and second purge passages when the engine E is started may be used.

In this embodiment, the first and second purge passages are merged on the way, and a single purge passage is formed from the middle. However, the first and second purge passages are not merged on the way but are independent. It may be constituted by a purge passage. In addition, the first and second canisters 21 and 22 are configured separately, but a partition member is placed in one canister to make the first and second canisters 21 and 22 respectively.
The second canister may be used. Further, in this embodiment,
Although the evaporated fuel generated in the fuel tank 2 is adsorbed to the first canister 21 via the second canister 22, the first fuel can be directly transferred from the fuel tank 2 without passing through the second canister 22.
You may make it adsorb | suck to the canister 21.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a fuel piping system of an automobile (first embodiment).

FIG. 2 is a schematic diagram showing an evaporated fuel pumping mechanism (first embodiment)
Example).

FIG. 3 is a block diagram showing a control system of the fuel supply device (first embodiment).

FIG. 4 is a flowchart showing purge control and evaporative injection control by a purge ECU (first embodiment).

FIG. 5 is a flowchart showing purge control / evaporative injection control after startup by a purge ECU (first embodiment).

FIG. 6 is a flowchart showing a purge flow rate control by a purge ECU (first embodiment).

FIG. 7 is a flowchart showing an evaporative injection control at the time of startup by a purge ECU (first embodiment).

FIG. 8 is a block diagram showing a control system of the fuel supply device (second embodiment).

[Explanation of symbols]

 E engine (internal combustion engine) 1 fuel supply device 2 fuel tank 3 liquid fuel injection device 4 evaporative fuel evaporation prevention device 5 intake pipe 11 fuel pump 13 fuel injection valve 21 first canister 22 second canister 23 canister switching valve (passage switching means) 25) Canister communication path 26 First switching path 27 Second switching path 30 Fuel-driven purge pump 32 Purge control valve 41 Motor-driven purge pump 42 Communication path 50 Engine ECU (fuel injection control means) 54 Cooling water temperature sensor ( Temperature detection means) 55 Intake air temperature sensor (temperature detection means) 60 Purge ECU (purge control means) 64 Tank temperature sensor (tank temperature detection means)

Continuation of the front page (72) Inventor Ichika Minagawa 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside DENSO Corporation

Claims (16)

[Claims] (A) a fuel tank for storing fuel to be supplied to an internal combustion engine; (b) a first canister for adsorbing evaporated fuel generated in the fuel tank; and (c) a fuel tank generated in the fuel tank. (D) a first purge passage communicating the first canister with the intake side of the internal combustion engine, and (e) a second purge passage connecting the first canister with the intake side of the internal combustion engine. And (f) supplying the fuel vapor in the second canister to the intake side of the internal combustion engine via the second purge passage when the internal combustion engine is started. After starting, the first
A purge control means for supplying the fuel vapor in the canister to the intake side of the internal combustion engine through the first purge passage. 2. The purge control means includes a purge pump for forcibly pumping the fuel vapor in the second canister to the internal combustion engine in the middle of the second purge passage. The evaporated fuel evaporation prevention device according to claim 1, wherein the purge pump is operated to supply the evaporated fuel in the second canister to an intake side of the internal combustion engine. 3. The apparatus according to claim 1, wherein the first canister adsorbs fuel vapor generated in the fuel tank via the second canister. . 4. A purge switching means for switching between the first purge passage and the second purge passage, a first switching passage communicating between the first canister and the passage switching means, A second switching passage communicating the second canister with the passage switching unit, a communication passage communicating the passage switching unit with the intake side of the internal combustion engine, and a communication passage provided in the communication passage. A purge control valve that adjusts a supply amount of evaporative fuel supplied to an intake side of the internal combustion engine via the internal combustion engine.When the internal combustion engine is started, the purge control valve is opened, and the passage switching means is used. The second purge passage is formed by communicating the second switching passage with the communication passage. After the internal combustion engine is started, the purge control valve is opened, and the first passage is opened by the passage switching means. Exchange passage and the communication passage and the evaporative fuel evaporative emission control system according to any one of claims 1 to 3, characterized in that to form the first purge passage by communicating. 5. The apparatus according to claim 1, wherein the second purge passage communicates the suction port of each combustion chamber of the internal combustion engine with the second canister.
The evaporative fuel evaporation prevention device according to any one of the first to third aspects. 6. A temperature detecting means for detecting a temperature around the second canister, wherein the purge control means detects a temperature around the second canister detected by the temperature detecting means when the internal combustion engine is started. 6. The fuel supply system according to claim 1, wherein the supply of the fuel vapor from the second canister to the intake side of the internal combustion engine is stopped when the temperature is lower than a predetermined temperature. The evaporative fuel evaporation prevention device as described in the above. 7. The purge control means includes evaporative fuel amount calculating means for calculating an evaporative fuel amount in the second canister, wherein the evaporative fuel amount calculated by the evaporative fuel amount calculating means when the internal combustion engine is started. The supply of evaporated fuel from the second canister to the intake side of the internal combustion engine is stopped when the internal combustion engine is started when the amount of evaporated fuel in the two canisters is smaller than a predetermined amount. An evaporative fuel evaporation prevention device according to claim 6. 8. An in-tank temperature detecting means for detecting a temperature in the fuel tank, and an in-tank pressure setting means for setting a pressure in the fuel tank; Generation amount calculation means for calculating the generation amount of fuel vapor per unit time from the temperature in the fuel tank detected by the temperature detection means and the pressure in the fuel tank set by the tank pressure setting means And an integrated amount calculating means for integrating the generated amount of evaporated fuel per unit time calculated by the generated amount calculating means to calculate the evaporated fuel in the second canister. 8. The evaporated fuel evaporation prevention device according to 7. 9. A fuel tank for storing fuel to be supplied to the internal combustion engine; (b) a first canister for adsorbing evaporated fuel generated in the fuel tank; and (c) a fuel tank generated in the fuel tank. (D) a first purge passage communicating the first canister with the intake side of the internal combustion engine, and (e) a second purge passage connecting the first canister with the intake side of the internal combustion engine. And (f) supplying the fuel vapor in the second canister to the intake side of the internal combustion engine via the second purge passage when the internal combustion engine is started. After starting, the first
Purge control means for supplying the fuel vapor in the canister to the intake side of the internal combustion engine through the first purge passage; (g) a fuel pump for supplying fuel to the internal combustion engine; and (h) a fuel pump. A fuel injection valve for injecting the supplied fuel into the internal combustion engine; and (i) an evaporative fuel adsorbed in the second canister by the purge control means through the second purge passage to intake air of the internal combustion engine. A fuel injection control means for reducing the amount of fuel injected into the internal combustion engine by the fuel injection valve when the fuel is supplied to the fuel injection valve, or stopping injection of fuel to the internal combustion engine by the fuel injection valve. A fuel supply device provided with. 10. The purge control means includes a purge pump for forcibly sending the fuel vapor in the second canister to the internal combustion engine in the middle of the second purge passage. The fuel supply device according to claim 9, wherein the purge pump is operated to supply fuel vapor in the second canister to an intake side of the internal combustion engine. 11. The fuel supply device according to claim 9, wherein the first canister adsorbs fuel vapor generated in the fuel tank via the second canister. 12. The purge control means includes: a passage switching means for switching between the first purge passage and the second purge passage; a first switching passage for communicating the first canister with the passage switching means; A second switching passage communicating the second canister with the passage switching unit, a communication passage communicating the passage switching unit with the intake side of the internal combustion engine, and a communication passage provided in the communication passage. A purge control valve that adjusts a supply amount of evaporative fuel supplied to an intake side of the internal combustion engine through the internal combustion engine. When the internal combustion engine is started, the purge control valve is opened and the passage switching means The second purge passage is formed by communicating the second switching passage with the communication passage. After the internal combustion engine is started, the purge control valve is opened, and the second passage is opened by the passage switching means. Claim and forming the first purge passage by communicating with the communication passage and switchable passages 9 through claim 11
The fuel supply device according to any one of the above. 13. The apparatus according to claim 9, wherein the second purge passage communicates the suction port of each combustion chamber of the internal combustion engine with the second canister. Fuel supply system. 14. A temperature detecting means for detecting a temperature around the second canister, wherein the purge control means detects a temperature around the second canister detected by the temperature detecting means when the internal combustion engine is started. 14. The system according to claim 9, wherein when the temperature is lower than a predetermined temperature, the supply of the fuel vapor from the inside of the second canister to the intake side of the internal combustion engine is stopped.
The fuel supply device according to any one of the above. 15. The fuel cell system according to claim 15, wherein said purge control means includes an evaporative fuel amount calculating means for calculating an evaporative fuel amount in said second canister, wherein said evaporative fuel amount calculated by said evaporative fuel amount calculating means when said internal combustion engine is started. 10. The supply of evaporative fuel from the second canister to the intake side of the internal combustion engine when the internal combustion engine is started, when the amount of evaporative fuel in the two canisters is smaller than a predetermined amount. Claim 14
The fuel supply device according to any one of the above. 16. An in-tank temperature detecting means for detecting a temperature in the fuel tank, and an in-tank pressure setting means for setting a pressure in the fuel tank; Generation amount calculation means for calculating the generation amount of fuel vapor per unit time from the temperature in the fuel tank detected by the temperature detection means and the pressure in the fuel tank set by the tank pressure setting means And an integrated amount calculating means for integrating the generated amount of evaporated fuel per unit time calculated by the generated amount calculating means to calculate the evaporated fuel in the second canister. 16. The fuel supply device according to item 15.