JPS6021499Y2 - Engine evaporative gas recovery device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for recovering evaporated gas from a carburetor or a crankcase.

Generally, in an automobile engine, unburned gas called blow-by gas may leak from the combustion chamber and flow into the crank chamber.

Since this blow-by gas contains components such as HC9CO9NOx, lead, and moisture, if it is allowed to remain in the crank chamber, it will cause sludge to grow in the lubricating oil and cause deterioration of the lubricating effect.

This deteriorated oil then flows into the lubricating parts and cylinder head through the oil passages of the cylinder block, accelerating the wear of the valves and lubricating parts.

As mentioned above, this blow-by gas contains HC, Co, NO
Because it contains a large amount of harmful gas components such as was.

On the other hand, in air cleaners, during high-temperature operation, during dead soak after high-load operation, or when left in high-temperature conditions, evaporated fuel gas from the float chamber of the carburetor passes through the air vent pipe and may accumulate and fill the air cleaner. .

The higher the temperature of the engine, the carburetor, or the surrounding area, the more this evaporative gas is generated.When the air cleaner is full, it enters the rad cover into the cylinder through the blow-by gas return passage, or They are introduced into the canisters, where they are retained and accumulated.

In the evaporated gas in the canister, only the fuel components are adsorbed by an adsorbent such as activated carbon, and the air is released into the atmosphere.

The adsorbed fuel components are recycled to the intake system and re-combusted during the next engine start.

In addition, the evaporated gas that stays and accumulates in the rad cover of the cylinder gradually makes the air-fuel ratio here richer over time, reaching the flammable range.

Then, there is a risk that sparks or backfires caused by the next engine start may ignite and cause an explosion, and in severe cases, it may cause engine trouble such as damage to the cylinder head.

Therefore, in view of the above-mentioned drawbacks of the conventional evaporative gas treatment measures, the present invention has been improved by providing a blow-by gas passage that communicates the inside of the rad cover and the air cleaner to the cylinder of the engine, and a passage that communicates the canister and the blow-by gas passage. At the connection point, there is a three-way control valve that switches the connection of the passage so that when the engine starts, the inside of the cylinder head cover communicates with the air cleaner, and when the engine stops, the canister and the air cleaner communicate with each other, or a three-way control valve that controls the temperature of the engine, etc. At least one of the three-way control valves detects the temperature and switches the connection of the passage so that the canister and the air cleaner are communicated if the temperature is above a predetermined temperature, and the inside of the rad cover and the air cleaner are communicated with the cylinder if the temperature is below a predetermined temperature. The purpose is to treat engine evaporation gas and blow-by gas by installing one to solve engine troubles.

The configuration of the present invention will be explained below according to the embodiments shown in the drawings.

Fig. 1 shows the first embodiment of the present invention, in which 1 is a cylinder head, 2 is a cylinder cover, 3 is an air cleaner, 4 is a canister containing a built-in adsorbent for adsorbing evaporated fuel gas, and 15 is an intake air It is a passage.

A carburetor 6 is disposed downstream of the air cleaner 3 in the intake passage 5, and an air bend pipe 7 is provided facing into the air cleaner 3 from its float chamber 8.

Reference numeral 9 indicates a blow-by gas passage that communicates the inside of the rad cover 2 and the air cleaner 3 to the cylinder, and 10 indicates a passage that communicates the canister 4 with the blow-by gas passage 9.

At the connection point between these passages 9 and 10, there is a
A three-way control valve 12 is arranged to open and close passages in three directions by turning the ignition switch 11 ON and OFF, which is one means for indicating a stop.

13 is the air hole of canister 4, 14 is the canister 4
This passage has a throttle 16 that communicates the intake passage 5 with the vicinity of the throttle valve 15.

Note that 17 is a gas-liquid separation device having a blow-by gas maze.

The three-way 10-control valve 12 is the ignition switch 11.
It is set so that the inside of the cylinder rad cover 2 and the air cleaner 3 are communicated with each other when the engine is started (N), and the canister 4 and the air cleaner 3 are communicated with each other when the engine is stopped (OFF).

As a result, when the engine is stopped, such as during high-temperature operation, dead soak after high-load operation, or when left in a high-temperature state, the air vent pipe 7 is removed from the float chamber 8 of the carburetor 6.
The evaporative gas of the fuel that evaporates into the air cleaner 3 through
When the air cleaner 3 is full, the canister 4
Here, the fuel component and air component are separated, and only the air component is released into the atmosphere through the atmospheric hole 13.

Fuel components are adsorbed by an adsorbent such as activated carbon. For this reason,
Evaporated gas is not retained or accumulated within the cylinder cover 2.

While the engine is starting, the inside of the rad cover 2 and the air cleaner 3 are always in communication with the cylinder.
The blow-by gas that has entered the engine and accumulated there and the blow-by gas inside the crank chamber are collected in the intake system and re-combusted.

During engine startup, the negative pressure in the intake passage 5 forms an air flow path that flows from the air hole 13 of the canister 4 through the inside of the canister, through the passage 14, and into the intake passage 5. Due to the flow, the fuel components adsorbed and held by the adsorbent when the engine is stopped are desorbed and sent to the re-combustion process.

In this case, the intake passage opening of the passage 14 is arranged so that it is upstream of the throttle valve 15 when the engine is idling, and downstream of the throttle valve 15 during normal operation and high-load operation, and is arranged so that it is located downstream of the throttle valve 15 when the engine is idling. This is to prevent a large amount of fuel from being sent from the canister 4 to the re-combustion process when the engine is at an unstable idle, that is, to prevent the air-fuel ratio from becoming too rich and causing misfire.

Incidentally, the above description has been made based on the case where the three-way control valve 12 is operated in conjunction with the ignition switch 11, but as shown in the embodiment A of FIG. During startup, the control valve 22 is moved as shown by the chain line by the intake negative pressure to communicate the inside of the air cleaner 3 and the cylinder to the rad cover 2, and during the stop, the air cleaner 3 and the canister 4 may be communicated with each other.

Furthermore, instead of using the pressure fluctuations in the intake passage 5, it is also possible to use the pressure fluctuations in the exhaust passage E, as in the embodiment of the bad day shown in the figure.

In this case, the exhaust pressure of the exhaust gas during startup is transmitted to the control valve device 21 through the orifice 01 surge tank T in the passage 18, and the valve 42 moves as shown by the chain line to the air cleaner 3.
and the inside of the herad cover 2 are communicated with each other.

When the engine is stopped, the exhaust pressure becomes atmospheric pressure, and the valve 42 returns to the position shown by the solid line, and the air cleaner 3 and canister 4 are communicated with each other.

Furthermore, as in the embodiment shown in FIG. 3, the passage may be switched based on a signal from a thermosensor that detects the temperature of the engine or the like.

In this case, if the signal from the thermosensor that detects the temperature of the engine room is at a predetermined temperature, e.g. 80°C or higher, a large amount of evaporative gas will be generated, so the canister 4 and the air cleaner 3 are communicated so that the signal is lower than the predetermined temperature. If so, the rad cover 2 and the air cleaner 3 should be communicated to the cylinder.

In this way, it is also possible to provide the three-way control valve 32 operated by a thermosensor that detects the temperature of the engine, such as engine temperature, carburetor section or intake air temperature.

The embodiment shown in FIG. 4 is a combination of the embodiment shown in FIG. 1 and the embodiment shown in FIG.

In this case 1, during starting when the ignition switch 11 is turned on, the air cleaner 3 communicates with the inside of the rad cover 2 through the passage 9, the control valve 12', the passages 9a and 9d, and the inside of the rad cover 2. Ru.

Furthermore, when the engine is stopped with the ignition switch 11 turned OFF, if the temperature is below a predetermined temperature, the air cleaner 3 is connected to the inside of the head cover 2 via the passage 9, control valve 12', passage 9b, control valve 32', passages 9c and 9d. When the temperature exceeds a predetermined temperature, the air cleaner 3 and the passage 9, the control valve 12',
It communicates with the canister 4 via the passage 9b, the control valve 32', and the passage 10.

This makes it possible to provide an evaporative gas recovery device that can be adapted to all operating conditions of the engine.

In this invention, when starting the engine, the blow-by gas passage connecting the engine cylinder, the inside of the rad cover and the air cleaner, and the passage connecting the canister and the above-mentioned blow-by gas passage are connected to each other. ,
The three-way control valve area, which connects the inside of the cylinder head cover and the air cleaner, and switches the connection of the passage so that the canister and the air cleaner communicate when the cylinder head is stopped, detects the temperature of the engine, etc. At least one of the three-way control valves is provided, which connects the canister and the air cleaner, and switches the connection of the passage so that the inside of the rad cover and the air cleaner are connected to the cylinder when the temperature is below a predetermined temperature. During soaking after high-load operation or when left in high-temperature conditions, it is possible to dispose of evaporated gas from the carburetor and crankcase without accumulating or accumulating in the rad cover. This can prevent engine troubles that may occur.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the first embodiment of the device of the present invention, Fig. 2 is a schematic diagram showing the second and third embodiments, and Fig. 3 is a schematic diagram showing the fourth embodiment. , FIG. 4 is a schematic diagram showing a fifth embodiment in which the first and fourth embodiments are combined. 2... Rad cover to cylinder, 3...
Air cleaner, 4... Canister - 9, 10.
...Passage, 12...Three-way control valve.

Claims (1)

[Scope of utility model registration request] At the connection point between the gas passageway that communicates the inside of the rad cover to the engine cylinder and the air cleaner, and the passage that communicates the canister and the above-mentioned proveby gas passage main, when starting the engine, the inside of the rad cover goes to the cylinder. A three-way control valve that communicates with the air cleaner and switches the connection of the passage to communicate the canister and air cleaner when stopped, detects the temperature of the engine, etc., and if the temperature is above a predetermined temperature, the canister and an air cleaner, and at least one of a three-way control valve that switches the connection of the passage so that the inside of the cylinder cover and the air cleaner are communicated when the temperature is below a predetermined temperature. Gas recovery equipment.