JPS5924839Y2 - fuel injected engine - Google Patents

Description

[Detailed description of the invention] This invention is a blow-by gas generated in engines, especially fuel-injected engines that are configured to stop fuel injection to some cylinders during light loads (including idling), or in the fuel tank. This invention relates to an apparatus for injecting vaporized fuel into an engine intake passage.

Conventionally, in order to prevent blow-by gas generated in the crankcase and evaporated fuel generated in the fuel tank from escaping into the atmosphere, the crankcase and fuel tank are connected to the intake passage, and the negative pressure generated in the intake passage when the engine is running is prevented. Devices that inhale and burn blow-by gas or vaporized fuel are known.

On the other hand, for example, as disclosed in Japanese Unexamined Patent Publication No. 53-16122, for the purpose of improving fuel efficiency, fuel injection to some cylinders is stopped during light loads and the remaining cylinders are operated. Fuel-injected engines have been proposed that are configured to perform.

However, if the crankcase or the upper part of the fuel tank is connected to the intake passage of this engine, blow-by gas and evaporated fuel are sucked into the cylinders where fuel injection is stopped during light loads and are discharged to the exhaust system without being combusted. This creates the problem of

The purpose of the present invention is to solve this problem.
By connecting at least one of the crankcase and the upper part of the fuel tank to the intake passage of the cylinder in which fuel is being injected, blow-by gas or evaporated fuel is introduced only into the cylinder in which fuel is injected, and is combusted in that cylinder. It is characterized by preventing release into the exhaust system.

Hereinafter, the present invention will be explained in detail with reference to the drawings showing embodiments.

The figure shows an embodiment of the present invention, in which 1 indicates cylinder E.
1. E2. E3. E4. In the crankcase of a six-cylinder engine having cylinders El, E6, 2 is an intake passage having thrower 1 to valve 3, which branches into passages 2a and 2b in the middle, and passage 2a connects cylinders El, E2, . Back to E3, passage 2b
is cylinder E4. E5. Each is connected to E6.

Reference numeral 4 indicates an injection nozzle for injecting fuel into each cylinder, which is provided in the intake passage just before each cylinder.

5 is an air tank, and 6 is a fuel tank.

The upper part of the fuel tank 6 is connected to the crankcase 1 via a steam pipe 7 and a ventilation pipe 8, and the steam pipe 7 and ventilation pipe 8 are connected to one branch passage 2a of the intake passage via an intake pipe 9. The suction pipe 9 is provided with a ventilation valve 1 that communicates with the suction pipe 9 at least under light load.
0 is provided to constitute an inhaler.

The ventilation valve 10 senses negative pressure generated in the intake passage 2 during engine operation, opens the intake pipe 9, and connects the -L portion of the crankcase 1 and the fuel tank 6 to the branch passage 2a of the intake passage 2.

Reference numeral 11 denotes a connecting pipe that connects the crankcase 1 and the air tank 17-5, and a charcoal canister 12 is provided in the middle.

The charcoal canister 12 adsorbs evaporated fuel generated in the upper space 6a of the fuel tank 6 when the engine is stopped, and prevents it from escaping into the atmosphere.

In the above six-cylinder engine, fuel is supplied from each injection nozzle 4 to all cylinders during medium and high loads, and the ignition order is E+, Es.
, E3. E6. E2. Operation is performed with E4, but when the load is light such as when idling or driving at low speed, half of the cylinders E4. Es, fuel injection to E6 is stopped and the injection of fuel to other cylinders E1. E2. Fuel is injected only into E3, and fuel is injected into cylinders El, E2. Operation is carried out only in E3.

In addition, due to the negative pressure generated in the intake passage 2 during engine operation, the ventilation valve 10 opens the intake pipe 9 and connects the crankcase 1 and the fuel tank 6 to the branch passage 2 of the intake passage 2.
Connects to a.

As a result, the blow-by gas generated in the crankcase 1, the evaporated fuel generated in the upper space 6a of the fuel tank 6, and the evaporated fuel adsorbed in the charcoal canister 12, together with fresh air from the air cleaner 5, are removed from the connecting pipe 11. The fuel is sucked into the branch passage 2a through the ventilation pipe 8, the steam pipe 7, and the suction pipe 9, and is introduced into the cylinders El, E2 and E3, where it is combusted together with the fuel injected from the injection nozzle 4.

As mentioned above, the upper part of the crankcase 1 and fuel tank 6 is equipped with a cylinder ELE that injects fuel even under light load.
2. Since it is connected only to the intake passage 2a of E3 and communicated with the ventilation valve 10 during engine operation,
Blow-by gas and evaporated fuel are transferred to cylinder E4, which stops fuel injection during light loads. Es.

Cylinder E1 where combustion is always performed without being introduced into E6
．． E2. It is introduced only into E3 and is burned reliably.

In the above embodiment, the intake pipe 9 is branched at the communication pipe 9' as shown by the dashed line in the drawing, and the cylinder E4. E5. It is connected to the intake passage 2b of cylinder E6, and the cylinder E4. E5. The intake device may be configured to include a valve 13 that closes the iron pipe when injection of fuel to E6 is stopped.

In this case, cylinder E4. E5. At light load when injection to E6 is stopped, blow-by and evaporated fuel is in cylinder El.

Blow-by and evaporated fuel are introduced only to E 2 and E 3, but during medium/high load when fuel is injected to all cylinders, blow-by and evaporated fuel are introduced to all cylinders and burned.

Furthermore, the present invention is not limited to six-cylinder engines as in the above embodiments, but can be easily applied to other multi-cylinder engines.

In addition, in the above embodiment, the blow-by gas and the evaporated fuel are both inhaled into the engine intake passage, but the present invention is not limited to this, and it is possible to inhale only the blow-by gas or only the evaporated fuel. Good too.

As described above, the present invention allows at least one of the crankcase and the upper part of the fuel tank to be connected only to the intake passage of the cylinder in which fuel is being injected during light loads when fuel injection to at least some cylinders is stopped. By communicating with each other, blow-by gas or evaporated fuel is reliably combusted within the cylinder and is prevented from being exhausted directly to the exhaust system.

[Brief explanation of the drawing]

The figure is a schematic diagram showing an embodiment of the present invention. 1: Crankcase, 2, 2 a, 2 b...
・Intake passage, 4: Fuel injection nozzle, 6: Fuel tank, (
E,,E2゜E3. E4. E5. E6): Cylinder.

Claims (1)

[Scope of utility model registration request] At least one of the crankcase and the upper part of the fuel tank is communicated with the intake passage, and the blow-by gas in the crankcase or the evaporated fuel in the fuel tank is sucked into the intake passage during engine operation, and is also supplied to some cylinders when the engine is lightly loaded. In a fuel-injected engine configured to stop fuel injection to some cylinders, during light load when fuel injection to some cylinders is stopped, fuel is injected into at least one of the crankcase and the upper part of the fuel tank. A fuel injection engine characterized by being equipped with an intake device that communicates only with the intake passage of the cylinder.