JPH04124517U - vapor recovery system - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to realize a vapor recovery system that can prevent air containing evaporated fuel in a fuel tank from being released into the atmosphere during a fuel injection operation. [Structure] A first evaporative fuel holding part communicates from the fuel tank with a first pipe passing through a check valve, and a second vaporized fuel holding part communicates with the fuel tank through a second pipe passing through a first on-off valve.
A third pipe is provided that directly communicates the first vaporized fuel holding section and the second vaporized fuel holding section, and the second vaporized fuel holding section is connected to the internal combustion via the second on-off valve. A fourth pipe is provided that communicates with the downstream side of the throttle valve of the engine suction pipe, and the first on-off valve is opened when fuel is injected into the fuel tank and when the internal combustion engine is operating, and when the internal combustion engine is operating and predetermined conditions are satisfied. A control section is provided for controlling the second on-off valve to open when the second on-off valve is opened.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to a vapor recovery system for internal combustion engines, especially for fuel injection. When the fuel tank cap is opened, evaporated fuel may be released into the atmosphere from the cap. This invention relates to a vapor recovery system that can effectively prevent air pollution.

0002

[Conventional technology]

In conventional internal combustion engines, as a countermeasure to the problem of vaporized fuel being released into the atmosphere, A canister that communicates with the fuel tank and adsorbs and holds evaporated fuel is installed, When the operating state of the canister is in the purge area that satisfies the predetermined conditions, the canister is adsorbed. Vapor recovery system that controls the release of retained vaporized fuel into the intake system of an internal combustion engine There are some that are equipped with a tem.

0003 An example of such a vapor recovery system for an internal combustion engine is shown in FIG.

0004 In FIG. 8, 102 is an air cleaner, which is connected to the air cleaner 102. The intake pipe 104 is connected via a carburetor and throttle body 106 (not shown). It communicates with the internal combustion engine 108. A throttle valve 110 is installed in the throttle body 106. I'm being kicked.

[0005] Further, in FIG. 8, 112 is a fuel tank provided with a fuel injection pipe 114. . The fuel tank 112 communicates with the upper part of the canister 118 via piping 116. Ru. The canister 118 has a large portion at the bottom opposite to the attachment portion of the pipe 116. An opening 120 that is open to air is provided, and a pipe 122 is connected to an on-off valve 124 from the top. The intake pipe 4 is connected to the downstream side of the throttle valve 10 via the intake pipe 4.

[0006] In the above configuration, the on-off valve 124 is normally closed, so the fuel tank The evaporated fuel generated in the pipe 112 is transferred from the pipe 116 to the canister 1 as shown by the arrow u. 18, and is adsorbed and stored in the canister 118.

[0007] When the operating state of the internal combustion engine is in a purge state that satisfies predetermined conditions, the on-off valve 1 24 is released. In addition, in this state, the throttle body 106 is provided with The throttle valve 110 is opened at a predetermined angle to create a flow of intake air in the intake pipe 4. Therefore, the air in the pipe 122 flows as shown by the arrow w and is sucked into the canister. The vaporized fuel adsorbed inside 118 is sucked out and replaced with fresh fuel from the opening 120. Since the atmosphere flows into the canister 118 as shown by the arrow v, the canister 11 8 is replaced with fresh air.

[0008] In addition, as a vapor recovery system for such an internal combustion engine, the Utility Model Application No. 63-1 There are some disclosed in Publication No. 21757 and Japanese Utility Model Application Publication No. 126550/1983. .

[0009] The one disclosed in Utility Model Application Publication No. 63-121757 has an ignition switch. When the fuel tank is turned off and the refueling switch is turned on, the fuel tank and evaporated fuel adsorption unit are A valve placed in the middle of the piping connects the pipes and releases the pressure inside the fuel tank when refueling. I'm trying to open it.

0010 In addition, what is disclosed in Utility Model Application Publication No. 63-126550 is that The main canister collects evaporated fuel, and the main canister communicates with the fuel tank only when fuel is injected. An auxiliary canister is installed, and the main canister is opened under operating conditions where the amount of intake air is equal to or higher than the first set value. The control valve installed in the purge passage communicating with the intake pipe is opened, and the intake air amount is set to the first setting. The auxiliary canister communicates with the intake pipe under operating conditions equal to or higher than the second set value. A control valve provided in the purge passage is opened.

[0011]

[Problem that the idea aims to solve]

By the way, in the conventional vapor recovery system, fuel is not poured into the fuel tank. When filling the fuel tank, empty the evaporated fuel in the fuel tank corresponding to the volume of fuel to be injected. The air contained therein is released to the atmosphere from the fuel inlet. In this way, evaporated fuel enters the atmosphere. Emissions are important from the perspective of preventing air pollution, but have traditionally been a never-ending problem. It was thought that However, there are moves to legalize it in the United States and other countries, so it is urgently necessary to There is a need to take countermeasures.

0012 In order to solve the above problem, this invention eliminates the vaporized fuel in the tank when fuel is injected. A container where the air can be properly disposed of after being stored without being released into the atmosphere. - The challenge is to realize a Paris cover system.

[0013]

[Means to solve the problem]

Therefore, in order to eliminate the above-mentioned inconvenience, this invention has been developed to When certain conditions are met, the evaporated fuel is absorbed and held in a predetermined evaporative fuel holding part by the internal combustion engine. In an internal combustion engine vapor recovery system that controls the exhaust gas to the intake system of the engine, A first evaporative fuel that communicates with the fuel tank through a first pipe that passes through a check valve. A second evaporator connected to the holding part and the fuel tank by a second pipe passing through the first on-off valve. The first evaporative fuel holder and the second evaporative fuel holder are directly connected to each other. A third pipe is provided to pass through the fuel vapor, and the second vaporized fuel holding part is connected to the fuel vapor via the second on-off valve. A fourth pipe communicating with the downstream side of the throttle valve of the internal combustion engine suction pipe is provided, and the fourth pipe is connected to the fuel tank. When the fuel is injected and the internal combustion engine is operated, the first opening/closing valve is opened and the internal combustion engine is operated. Control to open the second on-off valve when the fuel engine is operating and when predetermined conditions are satisfied. The present invention is characterized in that it is provided with a control section that performs the following operations.

[0014]

[Effect]

According to the configuration of this invention, when the first on-off valve is opened during the fuel injection operation, In both cases, by closing the second on-off valve, the supply fuel including evaporated fuel is supplied. The amount of air flows to the second evaporative fuel storage section and is stored, and when the internal combustion engine is stopped, the air is transferred to the first and second evaporative fuel storage sections. By closing the on-off valve, the internal pressure inside the fuel tank is high, which means that the amount of evaporated fuel is When the amount exceeds a certain amount, the evaporated fuel flows to the first evaporated fuel holding section and is stored, and the internal combustion engine When a predetermined condition is satisfied during operation, the first on-off valve and the second on-off valve are opened. By this, the evaporated fuel adsorbed in the first evaporated fuel holding part and the second evaporated fuel holding part is released downstream of the throttle valve in the internal combustion engine intake pipe, and evaporated fuel is in the fuel tank. There is no accumulation, and even when fuel is injected into the fuel tank, vaporized fuel does not enter the atmosphere. Not released.

[0015]

【Example】

Next, an embodiment of this invention will be described in detail based on the drawings.

[0016] Figures 1 to 5 show the structure of the first embodiment of the vapor recovery system based on this invention. Figure 6 shows the structure of the second embodiment of the vapor recovery system based on this invention. Figure 7 shows the structure of a third embodiment of the vapor recovery system based on this invention. It is something.

[0017] In FIG. 1, 2 is an air cleaner, and intake air is communicated with the air cleaner 2. The pipe 4 communicates with an internal combustion engine 8 via a throttle body 6. throttle The body 6 is provided with a throttle valve 10, and the intake pipe 4 is connected to the upstream side of the throttle body 6. 4-a and an intake manifold 4-b on the downstream side.

[0018] In addition, in Fig. 1, 12 is an injector, and the throttle body 6 has a diaphragm. A throttle sensor 14 is provided to detect the operating angle of the valve 10.

[0019] The fuel tank 16 is provided with a fuel injection pipe 18, and the fuel injection pipe 18 is provided with a fuel key. A cap 20 is attached.

[0020] The first pipe 22 from the fuel tank 16 passes through the check valve 24 to the first evaporator. It communicates with a canister 26 using activated carbon, which is a fuel holding part, and this canister 26 is provided with an opening 28 open to the atmosphere. In this embodiment, the canister 26 describes the case of a bottom type in which the opening 28 is at the top.

[0021] Further, the second pipe 30 from the fuel tank 16 is connected to the second vaporizer via the first on-off valve 32. It communicates with a vapor tank 34 which is a fuel holding section. The third pipe 36 The nister 26 and the vapor tank 34, which is a second vaporized fuel holding section, are communicated with each other.

[0022] A fourth pipe 38 from the vapor tank 34 is connected to the intake air via a second on-off valve 40. The piping 4 is connected to the intake manifold 4-b on the downstream side of the throttle body 6. Ru.

[0023] Further, a fuel injection chamber 42 is provided at the tip of the fuel injection pipe 18 of the fuel tank 16. Then, cover the tip of the fuel injection pipe 18 with the fuel cap 20 in the fuel injection chamber 42. A body side lid 44 is also provided.

[0024] Furthermore, the fuel injection chamber 42 is equipped with a switch that is turned on when the body side cover 44 is opened. A switch 46 is provided, and when this switch 46 is turned on, the first An electric circuit is provided to open the on-off valve 32.

[0025] 50 is a control unit that controls the throttle sensor 14 mentioned above and other predetermined signals. The internal combustion engine 8 is controlled by inputting the signal and outputting it to the injector 12 and the like. applicable system The controller 50 controls the second on-off valve 4 when the internal combustion engine 8 enters a predetermined operating state, which will be described later. 0, and also operates the first on-off valve 32 in parallel with the switch 46. An electric circuit is provided.

[0026] Inside the vapor tank 34, a plurality of partition walls 52 with one end open are provided as attachment parts. The second pipe 30 and the fourth pipe 38 and the third pipe 36 are separated. Therefore, it enters this vapor tank 34. If the evaporated fuel contains a liquid component or part of the evaporated fuel returns to liquid, it will naturally turn into gas. The component and liquid component are separated.

[0027] Next, the operation of the above configuration will be explained.

[0028] FIG. 2 shows that the internal combustion engine 8 has stopped operating and the fuel cap 20 and fuel tank 16 are closed. The state in which the body side lid 44 and the body side lid 44 are closed is shown.

[0029] In FIG. 2, the switch 46 detects that the body side cover 44 is closed and controls the Since the first on-off valve 32 and the second on-off valve 40 are closed by the operation of the control part 50, the combustion When the fuel vapor pressure in the fuel tank 16 exceeds the set pressure of the check valve 24, this Evaporated fuel flows into the canister 26 via the check valve 24 (see arrow a). It is adsorbed. In addition, some of the evaporated fuel that has flowed into the canister 26 flows through the third pipe 36. It flows through the vapor tank 34 (see arrow b) and is stored there.

[0030] In FIG. 3, the internal combustion engine 8 is operating, but the control unit 50 determines that the purge is not operating. It describes the situation. In other words, the internal combustion engine 8 is operating, but the purge is not operating. In this situation, the first on-off valve 32 is opened but the second on-off valve 40 is closed. There is. Therefore, the evaporated fuel in the fuel tank 16 is transferred from the second pipe 30 to the vapor tank 3. 4 (see arrow c), and further flows to the canister 26 via the third pipe 36. (see arrow d). Also, check the fuel vapor pressure in the fuel tank 16. When the pressure exceeds the set pressure of the check valve 24, the canister is The liquid flows into the tank 34 (see arrow a) and is adsorbed.

[0031] FIG. 4 shows that the internal combustion engine 8 has started operation and entered the preset purge operation state. It describes the situation at the time. The control unit 50 determines the purge operation and enters the purge operation state. Then, the first on-off valve 30 and the second on-off valve 40 are respectively opened.

[0032] In this situation, the throttle valve 10 of the throttle body 6 provided in the intake pipe 4 The intake pipe 4 is opened at a predetermined angle, and a flow of intake air is generated in the intake pipe 4. Therefore , the air in the fourth pipe 38 flows into the intake pipe downstream of the throttle body 6 provided in the intake pipe 4. The vapor accumulated in the vapor tank 34 is sucked into the take manifold 4-b. The generated fuel is transferred from the fourth pipe 38 to the downstream side engine of the throttle body 6 provided in the intake pipe 4. It is discharged into the intake manifold 4-b (see arrow e).

[0033] Further, the vaporized fuel accumulated in the canister 24 is also transferred from the third pipe 36 to the vaporized fuel. Flows through the tank 34 (see arrow f), and is provided from the fourth pipe 38 to the intake pipe 4. is discharged into the intake manifold 4-b on the downstream side of the throttle body 6 (as shown by the arrow). (See mark e). In addition, fresh air flows from the opening 28 of the canister 26 toward the atmosphere. The air flow (see arrow g) flows in and removes the evaporated fuel adsorbed into the canister 26. Replace with fresh air.

[0034] Furthermore, the fresh air that has passed through the canister 26 is vaporized from the third pipe 36. The vaporized fuel in the vapor tank 34 is transferred to fresh air (see arrow f). Replace with

[0035] Further, the evaporated fuel in the fuel tank 16 is transferred to the vapor tank 3 via the second pipe 30. 4 (see arrow c), and further from the fourth pipe 38 to the slot provided in the intake pipe 4. is released into the intake manifold 4-b on the downstream side of the body 6 (see arrow e). . When the fuel vapor pressure in the fuel tank 16 exceeds the set pressure of the check valve 24, It flows into the canister 26 via this check valve 24 (see arrow a).

[0036] As described above, the vapor tank 3 having a predetermined volume serves as the first vaporized fuel holding section. 4, the effect of adjusting the pressure inside the fuel tank 16 by the vapor tank 34 is It has the ability to remove evaporated fuel from the fuel tank in a short time.

[0037] In addition, since the vapor tank 34 is provided with a plurality of partition walls 52, the vaporized fuel to be absorbed is Air in the fuel tank containing fuel can accumulate without being released directly, and can also It has the function of separating the liquid while the air containing the evaporated fuel flows. Therefore, it is suitable for adsorbing liquid substances compared to canisters.

[0038] FIG. 5 shows the situation when the operation of the internal combustion engine 8 is stopped and fuel is injected into the fuel tank 16. is written. To inject fuel, open the body side lid 44 and close the fuel cap 20. is removed, and a fuel injection gun 54 is inserted into the fuel injection pipe 18 instead. figure 5, 56 is a sealing member, which connects the fuel injection pipe 18 and the fuel injection gun 54. The gap between the fuel tank 16 and the fuel tank 16 is sealed to prevent the vaporized fuel in the fuel tank 16 from leaking.

[0039] When the body side cover 44 is opened, the switch 46 is activated and the first on-off valve 32 is opened. do. When fuel is injected from the fuel injection gun 54, the air inside the fuel tank 16 is It flows through the pipe 30 (see arrow j) and reaches the vapor tank 34, and further the vapor tank The water flows sequentially between the partition walls 52 in the canister 34 (see arrow k) and from the third pipe 36 to the canister. The water flows into the canister 26 (see arrow m), and then flows into the atmosphere from the opening 28 of the canister 26. (see arrow n). During this flow, the vaporized fuel contained in the air is During this flow, the liquid component of the fuel contained in the air is adsorbed by the nister 26, and the liquid component of the fuel contained in the air is absorbed into the air. It is separated by pattern tank 34 and remains. Therefore, the air flowing out from the opening 28 toward the atmosphere Air does not contain evaporated fuel.

[0040] According to the first embodiment, as described above, the evaporated fuel in the fuel tank 16 is At the time of entry, the vapor tank 34 connects to the atmosphere via the canister 26, so there is a large It is absorbed into the vapor tank 34 or canister 26 before being released into the air. follow Therefore, unlike conventional methods, the evaporated fuel in the fuel tank 16 is not directly released into the atmosphere. Never.

[0041] A second embodiment of the present invention is shown in FIG. will be explained using the same reference numerals.

[0042] The feature of this second embodiment is that the second vaporized fuel retention in the first embodiment is The vapor tank 34 is replaced with a canister 62 using activated carbon, and Along with this change, some piping was also changed.

[0043] That is, in FIG. 6, the first pipe 22 from the fuel tank 16 is connected to the check valve 2. 4 to the first canister 26, and the first canister 26 is connected to the atmosphere. An opening 28 is provided through the opening 28. A second pipe 30 from the fuel tank 16 connects the first on-off valve 32. via the second canister 62, and the second canister 62 has a An opening 64 is provided. Further, a third pipe 66 is connected to the first canister 26 and the second key. It communicates with the canister 62.

[0044] A fourth pipe 68 from the third pipe 66 is connected to the intake pipe 4 via a second on-off valve 70. It branches and communicates with the intake manifold 4-b on the downstream side of the throttle body 6. Ru.

[0045] The second embodiment has a base that is the second vaporized fuel holding section in the first embodiment described above. The pattern tank 34 was replaced with a canister 62, and the piping was changed due to this change. This is a partially modified version. Therefore, the effect is similar to that explained with reference to FIGS. 1 to 5. This is almost the same as the first embodiment.

[0046] That is, the operation of the internal combustion engine was stopped and the fuel cap 20 of the fuel tank was closed. In the situation shown in FIG. 6, the first on-off valve 32 and the second on-off valve 70 are closed. Therefore, the fuel vapor pressure in the fuel tank 16 exceeds the set pressure of the check valve 24. Then, the flow passes through this check valve 24 to the first canister 26 (see arrow a). (see) and is adsorbed. In addition, a part of the water passes through the third pipe 66 to the second canister 62. It flows (see arrow b) and is adsorbed.

[0047] In a situation where the internal combustion engine is operating but the purge is not operating, in FIG. The first on-off valve 32 is opened, but the second on-off valve 70 is closed. Therefore, fuel The evaporated fuel in the tank 16 flows from the second pipe 30 to the second canister 62 (arrow c reference), and further flows to the first canister 26 via the third piping 66. (See arrow d). Also, check the fuel vapor pressure in the fuel tank 16. When the pressure exceeds the set pressure of the valve 24, the first key is released through the check valve 24. The liquid flows into the canister 26 (arrow a) and is adsorbed.

[0048] When the internal combustion engine operates and enters the purge operation state, in FIG. 32 and the second on-off valve 68 are each opened.

[0049] In this situation, the throttle valve 10 of the throttle body 6 provided in the intake pipe 4 It is opened at a predetermined angle, and a flow of intake air is generated in this intake pipe 4. Therefore , the air in the fourth pipe 68 flows into the intake pipe on the downstream side of the throttle body 6 provided in the intake pipe 4. is sucked into the take manifold 4-b (see arrow e) and stored in the second canister 62. The accumulated evaporated fuel and the evaporated fuel accumulated in the first canister 26 are connected to the third pipe 6. 6 to the downstream side of the throttle body 6 provided in the intake pipe 4 via the fourth pipe 68 It is discharged into the intake manifold 4-b (see arrow e). Also, the second canister A flow of fresh air (see arrow f) flows through the opening 64 which is open to the atmosphere at 62. The evaporated fuel adsorbed in the second canister 62 is replaced with fresh air, and the first Fresh air flows from the opening 28 of the canister 26 to the atmosphere (arrow g ) flows into the first canister 26 and the vaporized fuel adsorbed in the first canister 26 is placed in fresh air. will be replaced.

[0050] The evaporated fuel in the fuel tank 16 is transferred from the first pipe 30 (see arrow c) to the third pipe. Downstream of the throttle body 6 provided in the intake pipe 4 via the pipe 66 and the fourth pipe 68 It is discharged into the side intake manifold 4-b (see arrow e).

[0051] When the body side cover 44 is opened, the switch 46 is activated and the first on-off valve 32 is opened. do. When fuel is injected from the fuel injection gun, the air inside the fuel tank 16 flows into the second pipe. 30 (see arrow c) and reaches the second canister 62, where the evaporated fuel is adsorbed. The remaining air is released to the atmosphere through opening 64 (see arrow h).

[0052] Further, the evaporated fuel reaches the first canister 26 via the third pipe 66 and is adsorbed. The remaining air is then released into the atmosphere through the opening 28 (see arrow j).

[0053] According to the second embodiment, as described above, the evaporated fuel in the fuel tank is is connected to the atmosphere through two canisters, so it evaporates before being released into the atmosphere. Fuel is absorbed into the canister. Therefore, as in the past, evaporative combustion in the fuel tank There is no direct release of air into the atmosphere.

[0054] In the second embodiment in which the second canister 62 is used as the second evaporated fuel holding section, as described above, The required volume can be made smaller than the first embodiment using a vapor tank. .

[0055] A third embodiment of the present invention is shown in FIG.

[0056] The feature of this third embodiment is that the structure shown in FIG. The canister 26 which is the holding part and the downstream side of the throttle body 6 provided in the intake pipe 4 The intake manifold 4-b is connected to the intake manifold 4-b by the fifth piping 72 via the third on-off valve 74. It was passed through.

[0057] That is, the fifth pipe 72 is connected from the canister 26 via the third on-off valve 74. Intake manifold 4-b on the downstream side of the throttle body 6 of the intake pipe 4 is connected to.

[0058] As mentioned above, the third embodiment adds the third on-off valve 74 and the fifth pipe 72 to the first embodiment. Since this is an addition, its function is the same as that of the first embodiment explained with reference to FIGS. 1 to 5. It is almost the same.

[0059] Therefore, the operation of the fifth pipe 72 equipped with the third on-off valve 74 different from that in FIG. 1 will be explained. .

[0060] The third on-off valve 74 is opened in the purge operation mode.

[0061] That is, when the internal combustion engine 8 is operating and the control unit 50 determines that it is in the purge operation state. Then, the third on-off valve 74 is opened by an operation signal from the control section 50.

[0062] When the internal combustion engine 8 is in operation, the slot provided in the intake pipe 4 The throttle valve 10 of the trunk body 6 is opened at a predetermined angle, and intake air is supplied to the intake pipe 4. The flow is occurring. Therefore, the air in the fourth pipe 38 flows through the slot provided in the intake pipe 4. The vapor is sucked into the intake manifold 4-b on the downstream side of the trunk body 6. The evaporated fuel accumulated in the tank 34 is transferred from the fourth pipe 38 to the intake pipe 4. It is discharged into the intake manifold 4-b on the downstream side of the throttle body 6 (arrow e reference).

[0063] Further, the vaporized fuel accumulated in the canister 26 is also transferred from the third pipe 36 to the vaporized fuel. Flows through the tank 34 (see arrow f), and is provided from the fourth pipe 38 to the intake pipe 4. is released into the intake manifold 4-b on the downstream side of the throttle body 6 (as indicated by the arrow). (see e).

[0064] Further, the evaporated fuel accumulated in the canister 26 in parallel with the above-mentioned flow is 5 The intake man on the downstream side of the throttle body 6 provided from the piping 72 to the intake piping 4 It is released directly into Nifold 4-b (see arrow e).

[0065] Additionally, an opening 28 in the canister 26 that is open to the atmosphere allows a flow of fresh air. (see arrow g) flows into the canister 26 and removes the evaporated fuel adsorbed into the canister 26 into fresh air. Furthermore, a flow (arrow) flows from the third pipe 36 via the vapor tank 34. (see mark f), the downstream side of the throttle body 6 provided in the intake pipe 4 from the fourth pipe 38 is discharged into the intake manifold 4-b (see arrow e).

[0066] As mentioned above, the vaporized fuel accumulated in the canister 26 passes through the vapor tank 34. It is discharged through two routes, the third pipe 36 and the fifth pipe 72. This two Two paths set the purge diversion ratio by presetting their respective flow resistances can do.

[0067] In other words, the amount of gas purged from the fuel tank 16 through the second pipe 30 is too large. If this occurs, there is a risk that the inside of the fuel tank 16 will become negative pressure, so the fifth pipe 72 Preventing this by providing a direct discharge path from canister 26 I can do it.

[0068] As mentioned above, the fifth on-off valve is closed except in the purge operation mode. The third embodiment is the same as the first embodiment except for the purge operation mode, and its effects are The result is the same as the first implementation except for the addition of the effect that there is no risk of negative pressure in the fuel tank mentioned above. Similar to the example.

[0069]

[Effect of the idea]

According to the present invention described above, the first pipe from the fuel tank via the check valve The first vaporized fuel holding part communicates with the second vaporized fuel holding part which is connected to the fuel tank via the first on-off valve. A second evaporative fuel holding section is provided which communicates with the first evaporative fuel holding section through piping. In addition to providing a third pipe that directly communicates with the second evaporative fuel storage section, A fourth pipe that connects the holding part to the downstream side of the throttle valve of the internal combustion engine suction pipe via the second on-off valve. A pipe is installed, and the first on-off valve is turned on when injecting fuel into the fuel tank and when operating the internal combustion engine. When the internal combustion engine is operating and a predetermined condition is satisfied, the second opening and closing operation is performed. Since a control unit is provided to control the opening of the valve, it is possible to open the first on-off valve when fuel is injected. At the same time, the second on-off valve is closed, and the evaporated fuel flows to the second evaporated fuel holding section, and then The evaporated fuel flows to the second evaporative fuel holding section and is accumulated therein, and the fuel is put into the fuel tank. When the evaporative fuel in the fuel tank is not released into the atmosphere, the first and second evaporative fuels are The evaporated fuel in the fuel tank can be collected in the fuel storage section, and there is no risk of the evaporated fuel in the fuel tank being released into the atmosphere. It is possible to prevent air pollution without being harmful, and it also violates possible future legal regulations. There is nothing to fear.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a vapor recovery system showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating the operation of the vapor recovery system when the internal combustion engine is stopped and the fuel tank is not opened.

FIG. 3 is a configuration diagram illustrating the operation of the vapor recovery system when the internal combustion engine is operating and the purge is not activated.

FIG. 4 is a configuration diagram illustrating the operation of the vapor recovery system in a purge operating state during internal combustion engine operation.

FIG. 5 is a configuration diagram illustrating the operation of the vapor recovery system during fuel supply.

FIG. 6 is a configuration diagram of a vapor recovery system showing a second embodiment of the present invention.

FIG. 7 is a configuration diagram of a vapor recovery system showing a third embodiment of the present invention.

FIG. 8 is a configuration diagram of a vapor recovery system showing the prior art of the present invention.

[Explanation of symbols]

2 Air cleaner 4 Intake piping 8 Internal combustion engine 16 Fuel tank 24 Check valve 26 Canister 32 First on-off valve 40 Second on-off valve 34 Vapor tank

Claims (1)

[Scope of utility model registration request] [Claim 1] A vapor recovery cover system for an internal combustion engine that controls the vaporized fuel absorbed and held in a predetermined vaporized fuel holding portion to be released into the intake system of the internal combustion engine when the operating state of the internal combustion engine satisfies predetermined conditions. A first evaporated fuel holding part communicates with the fuel tank through a first pipe passing through the check valve, and a second evaporative fuel holding part communicates with the fuel tank through a second pipe passing through the first on-off valve, respectively. A third pipe is provided that directly communicates the first evaporative fuel holding section and the second evaporative fuel holding section, and the second evaporative fuel holding section is connected to the second evaporative fuel holding section.
A fourth pipe is provided which communicates with the throttle valve downstream side of the internal combustion engine suction pipe via the on-off valve, and opens the first on-off valve and shuts down the internal combustion engine when fuel is injected into the fuel tank and when the internal combustion engine is operated. A vapor recovery system comprising: a control section that controls the second on-off valve to open when the engine is operating and when predetermined conditions are satisfied.