JPS6039481Y2 - Evaporated fuel control device for internal combustion engine - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an evaporated fuel control device for an internal combustion engine.

The evaporated fuel generated from the fuel tank and vaporizer float chamber is collected by the evaporated fuel collection device without being discharged into the atmosphere.As the engine operates, the evaporated fuel collected by the collection device is guided to the intake side of the engine and burned. It is well known that this is done.

With the tightening of evaporative fuel emission regulations, the same regulations have come to be applied to two-wheeled vehicles, which are the main source of evaporative fuel, as well as four-wheeled vehicles.

Therefore, it has become necessary to use an evaporative fuel control device also in two-wheeled vehicles.

Compared to four-wheeled vehicles, two-wheeled vehicles have an outlet for extracting evaporated fuel from the fuel tank closer to the liquid level of the fuel tank, so driving the vehicle can cause problems such as starting, stopping, traveling, climbing steep slopes, descending, and overturning. Due to the waving phenomenon of the fuel in the fuel tank and changes in the liquid level, liquid fuel may flow out from the evaporative fuel outlet, resulting in deterioration of the performance of the evaporative fuel collection device (due to a decrease in the performance of the evaporative fuel collection device, Since the suppression of fuel emissions into the atmosphere is incomplete, evaporated fuel is emitted into the atmosphere, contributing to air pollution.

) Liquid fuel could be released into the atmosphere, contributing to air pollution or causing a fire.

The present invention is intended to solve the above-mentioned problems and effectively suppress the emission of vaporized fuel and liquid fuel into the atmosphere.

The present invention will be explained based on the embodiment shown in the drawings. In FIG. .

The upper air layer of the carburetor float chamber 5 and the fuel outflow control valve 3 are communicated through a circulation passage 4.

The air cleaner 8 and the canister 6 are communicated through a mixture passage 9.

The passages 2 and 9 are open to the same adsorbent 7 side of the canister 6, and an air inlet 30 is provided on the other side.

FIG. 2 shows the fuel outflow control valve 3, and the control valve main body is provided with an inlet pipe 11, an outlet pipe 12, and an outlet pipe 13 in the lower part.

Reference numeral 18 is a weight and is provided in the control valve body so as to be able to slide up and down, and a valve body 15 for opening and closing the inlet pipe 11 and the outlet pipe 12 is formed on the upper part of the weight.

The valve body 15 is in contact with a weight 18 via a valve spring 16 and a valve push rod 17, and as the weight 18 moves up and down, the inlet pipe 11
It is configured so that it can be seated and removed from a valve seat 14 provided on the side.

Reference numeral 19 denotes a spring that biases the weight 18 upward, and the biasing force is such that when the control valve body is in a vertical position, the weight 18 descends;
When the control valve body is tilted more than a predetermined amount, the component force of the weight 18 in the spring extension direction decreases, and the weight spring 19 expands by overcoming this component force, raising the weight 18 and pushing the valve push rod. 17, the weight 18 pushes up the valve spring 16 and the valve body 15,
As a result, the valve body 15 is seated on the valve seat 14, so that the inlet pipe 11 and the outlet pipe 12 are cut off.

When the control valve body is tilted more than a predetermined level, the upward movement of the weight 18 is restricted by the upper wall of the valve body, so that the force acting on the valve body 15 is limited so that it does not exceed a certain load.

A passage is provided in the earthen wall so that the passage is not blocked by the weight 18 when the weight 18 comes into contact with the upper wall of the valve body.

When the control valve body is tilted by a predetermined amount or more and a positive pressure of a predetermined amount or more is applied with the valve body 15 seated on the valve seat 14, the pressure overcomes the force of the valve spring 16 pushing the valve body 15, and the valve body 15 is separated from the valve seat 14, and the inlet pipe 11 and outlet pipe 1
It has the effect of allowing communication between the two.

FIG. 3 shows that the fuel outflow control valve 3 of FIG. 2 is tilted more than a predetermined level,
The valve body 15 is seated on the valve seat 14, and the inlet pipe 11 and the outlet pipe 1
2 is shown in a state where it is cut off.

FIG. 4 shows another embodiment, which is a modification of FIG. 2, and only the modified portion will be explained.

In FIG. 2, when the control valve body is in a vertical position, the inlet pipe 11 and the outlet pipe 12 are in communication, and when the control valve body is tilted more than a predetermined level, the valve body 15 seats on the valve seat 14 and the passage is blocked. In contrast, in FIG. 4, when the control valve body is in the vertical position, the valve body 15 is already seated on the valve seat 14, and if a positive pressure of more than a predetermined value acts on the inlet pipe 11 side, By pressing the valve spring 16, the valve body 15 is separated from the valve seat 14, and the inlet pipe 11 and the outlet pipe 12 are brought into communication.

Furthermore, when the control valve body is tilted more than a predetermined level, the force pushing the valve seat 14 of the valve body 15 increases and the evaporated fuel passage 2 is closed, so that a positive pressure greater than the above is applied to the inlet pipe 11 side. At times, the inlet pipe 11 and the outlet pipe 12 are in communication.

In addition, in the embodiment shown in FIG. 2, the inlet pipe 11 and the outlet pipe 13 communicate with each other in the vertical state, but are blocked by the valve body 15 when the incline exceeds a predetermined level, and in the blocked state, the inlet pipe 11 side communicates with the inlet pipe 11. When the positive pressure exceeds a predetermined level, the inlet pipe 11 and the outlet pipe 12 are configured to communicate with each other, but in the embodiment shown in FIG.
are shut off by a valve body 15, and when a positive pressure of more than a predetermined level acts on the inlet pipe 11 side, the inlet pipe 11 and the outlet pipe 13
The two are connected.

A valve mechanism consisting of a valve body 23, a valve spring 24, and a valve seat 22 that opens and closes the passage by vertical movement of a weight 18 is provided in the passage between the inlet pipe 11 and the outlet pipe 13. When the weight 18 is descending, the valve is in an open state, and when the weight 18 is tilted more than a predetermined level, the valve is in a closed state.

When the tilt exceeds a predetermined level, the force of the valve body 15 pushing the valve seat 14 increases, and at the same time, the weight 18 rises, causing the valve body 23 to move against the valve seat 22.
, and the passage is blocked.

At this time, when a positive pressure of a predetermined level or higher is applied to the inlet pipe 11 side, the valve body 15 separates from the valve seat 14, and the inlet v11 and the outlet pipe 12 are brought into communication.

The inlet pipe 11 and the outlet pipe 13 are disconnected.

A passage 21 is provided so that the passage to the outlet 13 side is not blocked by the weight 18 in the vertical state.

Only the modified portions of FIG. 5, which is a modified example of FIG. 4, will be explained.

In FIG. 4, the inlet pipe 11 and the outlet pipe 12 have a valve mechanism that allows flow only from the inlet pipe 11 side to the outlet pipe 12 side, whereas in FIG. In addition, a valve seat 2 that allows flow only from the outlet pipe 12 side to the inlet pipe 11 side
7. The difference is that the present invention includes a valve mechanism provided in the negative and positive passages 26 that includes a valve body 28 and a valve spring 29.

Another difference is that a separator 25 is provided between the inlet pipe 11 and the outlet pipe 12, and the outlet pipe 13 also opens into the separator 25.

Outlet pipe 1 of the fuel outflow control valve 3 in FIGS. 2, 4, and 5
The extraction position of No. 2 is the inlet pipe 11 when vertical and when tilted.
Preferably, the position is such that the liquid fuel from the outlet pipe 13 and the control valve 3 body does not flow out from the outlet pipe 12 to the canister 6 side. A restriction may be provided in the passage.

In the device constructed as described above, in the case of FIGS. 1 and 2, when the engine 10 is stopped, the evaporated fuel generated in the fuel tank 1 passes through the evaporated fuel passage 2 and the fuel outflow control valve 3. , is collected by the adsorbent 7 in the canister 6.

The vaporized fuel generated in the vaporizer float chamber 5 passes through the circulation passage 4 and the fuel outflow control valve 3, and is collected by the adsorbent 7 in the canister 6.

Since no suction negative pressure is applied to the air cleaner 8, the vaporized fuel adsorbed on the adsorbent 6 is not scavenged.

Next, when the engine 10 is stopped and the fuel tank 1 tilts more than a predetermined amount due to a fall or the like, liquid fuel tries to enter the evaporated fuel passage 2 from the opening in the fuel tank 1 of the evaporated fuel passage 2. The accompanying fuel outflow prevention valve 3 has a valve body 15 seated on the valve seat 14 as shown in FIG.
2 is cut off, liquid fuel does not enter the evaporative fuel passage 2.

At this time, the liquid fuel in the vaporizer float chamber 5 tries to enter the fuel outflow control valve 3 from the upper air layer of the float chamber 5 through the circulation passage 4. Since the opening position and the like are appropriate, liquid fuel does not enter the outlet pipe 12 side.

Next, when the fuel outflow control valve 3 when the engine 10 is stopped is tilted to a predetermined level or more, and the fuel tank 1 is heated by direct sunlight etc., evaporated fuel is generated and the internal pressure reaches a positive pressure higher than the predetermined pressure. The valve element 15 overcomes the urging force of the valve spring 16 pushing the valve element 15 and opens, and the pressure inside the fuel tank 1 is adjusted.

At this time, since the outlet pipe 12 is provided at a proper position, the evaporated fuel from the fuel tank 1 is collected in the canister 6 via the outlet pipe 12, through the evaporated fuel passage 2.

Further, the liquid fuel from the fuel tank 1 is circulated from the outlet pipe 13 through the circulation passage 4 into the vaporizer float chamber 5.

When the engine 10 is in operation, suction negative pressure acts on the mixture passage 9 that opens to the air cleaner 8, and due to the negative pressure,
Clean air is introduced from the air introduction port 30 of the caster 6.

When the clean air passes through the seven adsorbent layers, the evaporated fuel adsorbed on the adsorbent 7 is desorbed, flows into the intake system together with the clean air, and is burned in the combustion chamber.

Similar to when the engine 10 is stopped, when the engine is in operation, if the fuel tank is tilted more than a predetermined level, the inlet pipe 11 and the outlet pipe 12 are cut off, so that liquid fuel does not flow into the evaporative fuel passage 2.

In the embodiment shown in FIG. 4, which is a modification of FIG. Otherwise, the evaporated fuel will not reach the outlet pipe 12 side, so it acts to reduce the load on the adsorbent 7 and to prevent liquid fuel from entering into the evaporated fuel passage 2.

Moreover, if the valve body 23 is tilted more than a predetermined level, the valve body 23 will sit on the valve seat 22 and the outlet pipe 12 and the outlet pipe 13 will be cut off, which will prevent the liquid fuel in the carburetor float chamber 5 from entering the canister 6 side. ing.

The other functions are the same as those of the embodiment shown in FIG.

In the embodiment shown in FIG. 5, which is a modification of FIG. 4, the negative pressure passage 26 is provided on the inlet pipe 11 side, so that the inside of the fuel tank 1 becomes negative pressure due to fuel consumption and a decrease in fuel temperature. The valve body 28 separates from the valve seat 27 to open the valve, and atmospheric air is introduced from the canister 6, so that the negative pressure inside the fuel tank 1 is adjusted.

Further, when the fuel outflow control valve 3 is tilted more than a predetermined level and the inside of the fuel tank 1 becomes positive pressure more than a predetermined value, the valve element 15 is separated from the valve seat 14 and the valve is opened, vaporized fuel and liquid fuel are released from the fuel tank 1. The mixed fluid enters into the separator 25, but the liquid fuel is stored in the separator 25 depending on the appropriate separator 25 chamber volume, the outlet position of the outlet pipe 12, etc., and the evaporated fuel is transferred from the outlet pipe 12 to the adsorbent 7 of the canister 6. is collected by.

At this time, the fuel in the carburetor float chamber 5 is transferred to the outlet pipe 12 and the outlet pipe 13 due to the valve body 23 of the control valve 3 being seated on the valve seat 22.
This prevents the liquid fuel in the vaporizer float chamber 5 from entering the canister 6 side.

When it becomes vertical again, the valve body 23 of the control valve 3 touches the valve seat 22.
Therefore, the liquid fuel stored in the separator 25 is circulated into the vaporizer float chamber 5 through the circulation passage 4.

As described above, in the present invention, even in a two-wheeled vehicle in which the evaporated fuel outlet from the fuel tank is close to the fuel liquid level, vehicle operation (starting, stopping, traveling, climbing steep slopes, descending, etc.) ), even if the fuel in the fuel tank is undulated or the liquid level changes, the provision of a fuel outflow control valve will make it difficult for liquid fuel to enter the outlet, and even if it does, it will flow back to the carburetor float chamber. This makes it possible to prevent liquid fuel from flowing toward the evaporative fuel collection device, resulting in the following effects.

(a) Since performance deterioration of the evaporated fuel collection device due to liquid fuel intrusion can be prevented, emission of evaporated fuel into the atmosphere during long-term use can be suppressed.

(b) Since liquid fuel can be prevented from leaking into the atmosphere, air pollution and fires in vehicles can be prevented.

(C) When the canister is used as an evaporative fuel collection device, it is possible to prevent the performance deterioration of the adsorbent due to liquid fuel adsorption, making it possible to downsize the canister.
It is useful for improving vehicle mountability, reducing costs, etc.

Even in motorcycles that tend to overturn relatively frequently, the fuel outflow control valve can prevent liquid fuel from flowing out from the fuel tank and the carburetor float chamber, so even when overturning, the above-mentioned ■, ■■
The effect of this can be obtained.

In the embodiment shown in Fig. 1, a canister is used as an example of the evaporative fuel collection device, but the space in the crankcase or the space from the air cleaner to the intake pipe may be used as the evaporative fuel collection device. The effect is the same.

In addition to two-wheeled vehicles, the same effects as described above can also be obtained in four-wheeled vehicles.

[Brief explanation of the drawing]

Fig. 1 is a fuel system diagram of the fuel outflow control device according to the present invention, Fig. 2 is a vertical cross-sectional view of the fuel outflow control valve of the fuel reservoir according to the invention, and Fig. 3 is the fuel outflow control valve of Fig. 2. FIGS. 4 and 5 are longitudinal sectional views showing other embodiments. DESCRIPTION OF SYMBOLS 1... Fuel tank, 2... Fuel vapor passage, 3... Fuel outflow control valve, 4... Circulation passage, 5... Curved carburetor float chamber, 6... canister, 7... eye opening adhesive, 8... air cleaner,
9...Mixture passageway, 10...One engine, 11...
...Inlet pipe, 12.13・Bend/Exit pipe, 14...
・・・Valve seat, 15・Curve・Valve body, 16・・Valve opening spring, 17
... Valve push rod, 18... Bent weight, 19... Bent weight spring, 20.21... Passage, 22, 23... Bent valve seat, 24... ... Valve spring, 25 ... Separator, 26 ... Negative pressure passage, 27 ...
・Valve seat, 28・Curve・Valve body, 29... Valve spring, 3
0...Air inlet.

Claims (1)

[Scope of utility model registration request] A fuel outflow control valve 3 is provided in the evaporated fuel passage communicating between the upper air layer of the fuel tank and the evaporated fuel collection device, and is located at a height equal to or higher than the liquid level of the vaporizer float chamber.
An evaporation device for an internal combustion engine, characterized in that a recirculation passage 4 is provided to communicate the fuel outflow control valve and the carburetor float chamber, and a mixture passage is provided to communicate the evaporated fuel collection device to the engine intake system. Fuel control device.