JPS6027827B2 - Evaporated fuel recovery equipment for motorcycles, etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an evaporated fuel recovery device in a fuel tank of a vehicle, particularly a motorcycle.

In the evaporated fuel recovery device, evaporated fuel from a fuel tank is guided to a gas-liquid separation chamber of a separator, and the liquefied fuel separated in the gas-liquid separation chamber is recycled to the fuel tank, while the remaining evaporated fuel is recycled to the vaporized fuel. There is a system in which fuel is sent to a collection device, and conventionally, a check valve has been installed in the connection passage between the gas-liquid separation chamber and the fuel tank.

This check valve usually consists of a coil spring and a needle valve that is pressed by this spring and integrated into the car key that balances the motorcycle when it is normal.It is open when it is normal and allows vaporized fuel to pass through, but when it falls over, etc. When this becomes extremely troublesome, the valve closes due to an imbalance between the spring and the treadle, and the fuel is drained into the canister (vaporized fuel bottle storage device).
Although this is an excellent method for preventing leakage to the sides, this subordinate method had the following drawbacks. That is,
Since a check valve is interposed between the gas-liquid separation chamber of the separator and the fuel tank, the fuel liquefied in the separator cannot be smoothly returned to the tank.

In other words, the gap serving as the reflux path becomes smaller, and the amount of reflux becomes extremely small due to the surface tension of the fuel.For example, if rapid deceleration is repeated, the fuel will flow into the separator but will not reflux. In some cases, the fuel formed a bubble inside the separator and leaked out into the canister.
As a result, the performance of the adsorbent in the canister was severely degraded. Furthermore, in motorcycles and the like where there is a lot of vibration, the car key of this valve moves up and down strongly due to the vibration, and the valve seat and its contact portion receive a strong impact, which significantly deteriorates the durability performance. Furthermore, if a fuel tank with this structure is left with the valve closed due to an accident such as falling over, and the fuel tank is heated in this state, for example by solar heat, the internal pressure of the tank will rise and the tank will eventually become deformed. To prevent this deformation, a safety valve that opens just before the tank deforms is usually required, which is undesirable in terms of product cost.

The present invention has been made in view of the current situation.

That is, in the present invention, the check valve is incorporated between the gas-liquid separation chamber of the separator and the vaporized fuel construction device to prevent any adverse effect on the reflux of the liquefied fuel, and at this time, the check valve is It is integrated inside the separator to make it more compact. The most important feature is that the structure of the check valve itself is not one in which the needle valve is directly connected to a weight that operates due to overturning, etc.
The structure includes a second spring to absorb the impact of the car bell due to vibrations, and the needle valve is used as a barrier when high pressure is generated due to solar heat, etc. in an overturned situation, eliminating the need for a safety valve. This is what I did. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the entire structure of the evaporated fuel recovery device according to the present invention applied to a motorcycle. A separator 2 is attached to the upper wall of the fuel tank, and a check valve 3 is integrated inside the separator 2. It is built-in.

This separator 2, as shown in FIGS. 2 and 3,
A gas-liquid separation chamber 2A is formed inside by the separator body 4 and the separator lid 5, and the gas-liquid separation chamber 2A has a liquefied fuel reflux port 6 formed in a part of the bottom surface of the separator body, which also serves as an evaporated fuel inlet. It is passed through the upper space 7 of the fuel tank. The weight 8 of the check valve 3 has a flange 8 whose diameter expands upward, as shown in FIGS. 2 and 4.
The valve case 9 is housed in a cylindrical valve case 9 having a cylindrical shape and integrally formed with the separator body.

A first coil spring 10 is installed between the bottom of the dome 8a and the bottom of the case 9. Therefore, the heavy stirrup 8 is constantly urged upward in the figure by the sprocket IJ ring 10. An elastic member 11 made of rubber or the like for shock absorption is attached to the bottom and shoulders of the vehicle weight 8. At the top of the case 9, there is a cylindrical cap body 1 that houses the needle valve 12 and substantially constitutes a part of the valve case.
3 are iron-fitted together, and a vaporized fuel outlet valve seat 14 is formed at the upper end of the cap body 13, with which the needle valve 12 comes into close contact when the valve is closed.

The needle valve 12 has a conical tip, and preferably has a segment 16 at its lower part, as shown in FIG. 5, whose outer periphery is polygonal and forms a relatively large evaporative fuel passage 15 between the needle valve 12 and the inner wall surface of the cap. are joined. And this cylinder 1
A second coil spring 18 and a cylindrical intermediate rod 19 are mounted between the cylindrical portion 17 of 6 and the weight 8 in order from the top. It is adapted to abut against the portion 8b. In this case, the elastic force of the second coil spring 18 is sufficiently smaller than the elastic force of the first coil spring 10, and the needle valve 12 is engaged when the motorcycle is upright and stationary, or The valve is set to open very weakly. Therefore, the vaporized fuel passes freely through the outlet valve seat 14, or only when accompanied by a slight pressure. If the motorcycle falls over and tilts at an angle greater than a predetermined angle, the balance of forces is lost and the weight 8 is pressed against the spring 01 and slides toward the cap body 13, causing its shoulder to It moves until it hits the inner bracing part 13a of the body 13. As a result, the intermediary bar 19 also moves, and the needle valve 12 comes into close contact with the valve 14, and is firmly opened.
Even in this state, when the internal pressure of the gas-liquid separation chamber 2A becomes high due to heat such as solar heat, the second coil spring 18, which has less elasticity than the first coil spring 101, is compressed and the valve opens slightly. This prevents the fuel tank 1 from deforming. In other words, it also has the function of a safety valve. A groove 20 that forms a passage when the weight 8 comes into contact with the conflicting part 13a at the time of falling is carved on a part of the inner side of the cap body 13a on the left side in the figure. Below the treetops, the valve case 9 has a lotus through hole 2.
1 is drilled.

This lotus passage hole 21 opens into a vaporized fuel outlet 24 connected to a canister 26 as a vaporized fuel collection device, which will be described later. A check valve 23 is incorporated.

In this case, the other check valve 23 prevents the evaporated fuel in the fuel tank from flowing into the canister 26 due to engine suction pressure.
This is to prevent the needle valve 12 of the check valve 3 from reaching the valve, and should be installed when the needle valve 12 of the check valve 3 is always closed, or when the valve pressure is unreliable at low pressure even if the valve is open. As shown in FIG. 1, a canister 26 is connected to the vaporized fuel outlet 24 via a vaporized fuel pipe 25, and the vaporized fuel supplied from this pipe 25 is passed through the air intake of the canister 26 during engine operation. It is mixed with the air taken in through the inlet 27 and sent out through the pipe 28 to the engine intake manifold. A part of the separator lid 5 has a pressure pipe 29 that fits into the space 7 above the liquid level of the fuel tank 1.
A isobaric pipe connection port 30 to which is connected is projected.

This pressure pipe 29 opens into the space 7 at a distance from the recirculation port 6 in the longitudinal direction of the vehicle. Therefore, when the motorcycle is parked, for example, on a steep downhill slope, and the recirculation port 6 of the separator 2 is blocked by the fuel in the tank, even if the tank internal pressure increases, the action of the same pressure pipe 29 prevents the separator from closing. This prevents the internal liquid level from rising above the tank internal liquid level, reaching the outlet valve seat 14 of the check valve 3, and flowing out into the canister 26. In addition, 31 is a cap with a negative pressure valve attached to the upper surface of the fuel tank 1, and 32 is a filler pipe. Next, the operation of the device of the present invention having the above configuration will be explained in Figures 1 to 5.
This will be explained with reference to the embodiments shown in the figures.

When the motorcycle is in an upright position, the fuel evaporated in the fuel tank space 7 enters the gas-liquid separation chamber 2A of the separator 2.
The liquefied fuel is returned to the tank through the reflux port 6, while a portion of the vaporized fuel is passed through the check valve 3 directly (as is) or when it is under a small pressure, and is then transferred to another check valve 23. , and reaches the canister 26 via the vaporized fuel pipe 25. In this case, since there is no check valve in the liquefied fuel reflux path, the liquefied fuel reflux is carried out extremely smoothly. In order to reduce the variation in the opening pressure of the check valve 3, it is preferable to make the diameter of the outlet valve seat as large as possible. It is easier to flow into the valve case, so from this point of view, it is preferable to use small grade.
Taking both of these into consideration, the outlet valve seat 14 has two stages: a large light portion D and a small diameter portion d formed at the tip thereof.

Furthermore, if another check valve 23 is provided, the evaporated fuel in the tank will be transferred to the canister 26 by the engine's intake negative pressure.
In addition to preventing the fuel from immediately flowing into the tank 1, there is also the advantage that when the fuel is injected into the tank 1, it can be prevented from being poured beyond the lower end surface of the filler pipe 32 to which the cap 31 is attached. In this upright state, even if it is subjected to large vibrations due to, for example, driving on a rough road, the weight 8 will only hit the competing part 13a on the inside of the cap body, which is made durable. Since the village 11 is attached, the shock is absorbed and is not directly transmitted to the needle valve 12 and valve seat 14.

If the motorcycle falls over or something extreme happens, the balance of forces will be broken, the gun weight 8 will move from the spring 101, and the check valve 3 will be tightly closed, causing fuel to flow out to the canister side. There isn't. In this overturned state, if the tank is heated by solar heat or the like and the internal pressure of the tank rises to just before the tank deformation pressure, the needle valve 12 acts against the elastic force of the second coil spring 18, preventing the tank from deforming. Prevented. Therefore, it is not necessary to separately install a safety valve. Furthermore, if the motorcycle is parked on a steep downhill slope, the recirculation port 6 of the separator 2 will be immersed in fuel, and even if the internal pressure of the tank increases in this situation, the pressure pipe 29 will prevent the fuel from flowing out. It will not leak into the canister.

Next, modified examples of the device of the present invention will be explained with reference to FIGS. 6 to 12.

In FIG. 6, the outlet valve seat 14 of the check valve 3 is positioned toward the vaporized fuel outlet 24 leading to the canister 26 side,
The configuration is such that the valve 3 is closed in the direction in which vaporized fuel flows, and in this case, the other check valve 23 and pressure pipe 29 are not installed.

FIG. 7 shows a configuration in which a connection port 30 for the pressure pipe 29 is attached to the device shown in FIG. 6. FIG. 8 shows how the outlet valve seat 14 of the check valve 3 is connected to the gas-liquid separation chamber 2 as in the case of the first embodiment described above.
It is located on the A side, and the valve 3 is configured to close in the opposite direction to the flow direction of the vaporized fuel. In this case, the other check valve 23 and the same pressure pipe 29 are installed,
do not have. FIG. 9 shows the connection port 30 of the same pressure pipe 29 in the device shown in FIG.
This is the configuration with the . FIGS. 10 and 11 show a structure in which the upper part of the valve is shaped like a covered cylinder (the lid part is a lid 5 3)
4, or surrounded by a complete wall 35, in the latter case, a space 36 is further formed inside the surrounding wall 35, and a throttle hole 37 is formed in the upper part, and a liquefaction hole 37 is formed in the lower part. It has a configuration in which a fuel escape hole 38 is drilled, and in this case, the other check valve 23 and check valve 29 are not installed. In FIG. 12, the outlet valve seat 14 of the check valve 3 is located on the gas-liquid separation chamber 2A side, as in the case of the first embodiment, and the valve 3 is opened in the opposite direction to the flow direction of the vaporized fuel. The needle valve 12 is configured to act as a valve, and the needle valve 12 is seated on the outlet valve seat IA with the separator body in an upright state,
The valve is configured to open at low pressure.

In this case, other check valves 23 and pressure pipes 29 are not installed. In these various devices, substantially the same functions and effects as in the first embodiment can be obtained.

As is clear from the above, according to the present invention, since there is no component such as a check valve between the fuel tank and the separator, the reflux characteristics of the liquefied fuel are significantly improved.
In addition, the structure of the check valve is designed to absorb shocks caused by motorcycle vibration by using the first and second springs, which improves durability, especially the needle valve and the valve that receives the needle valve. The durability of the seat part is extremely good. Furthermore, it is an object of the present invention to provide an evaporated fuel recovery device that is inexpensive to manufacture since no safety valve is required, and is compact and particularly effective for vehicles with limited space, such as motorcycles, since the check valve is integrally built into the separator. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a partial vertical sectional view showing the whole of one embodiment of the device of the present invention. FIG. 2 is a longitudinal sectional view showing the separator of FIG. 1. 3 is a view taken from the direction of arrow A in FIG. 2. FIG. FIG. 4 is an enlarged longitudinal sectional view of the check valve of FIG. 2. Fifth
The figure is a cross-sectional view taken along the line V-V in FIG. 4. Figures 6 to 1
FIG. 2 is a longitudinal sectional side view showing another modification of the device of the present invention. 1...Fuel tank, 2...Separator, 2A
... gas-liquid separation chamber, 3... check valve, 7... space above the liquid level in the fuel tank, 8... dowel, 9... valve case, 10... first spring, 12... Needle valve, 14...Outlet valve seat, 18...Second spring, 19...Mediator valve, 23...Other check valve,
26... Canister (vaporized fuel collecting device), 34... Shield tube, 35... Record tube, 36... Space, 37...
- Throttle hole, 38...Liquefied fuel relief hole. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12

Claims (1)

[Claims] 1. Directing the vaporized fuel from the fuel tank to the gas-liquid separation chamber of the separator, and returning the liquefied fuel separated in the gas-liquid separation chamber to the fuel tank, while sending the remaining vaporized fuel to the vaporized fuel collection device. In the evaporated fuel recovery equipment,
A valve case that extends in the vertical direction and communicates with the gas-liquid separation chamber and the vaporized fuel collection device; a weight that is slidably inserted in the valve case in the vertical direction; and a weight that urges the weight upward. a needle valve that is housed in the valve chamber at a position above the weight and opposes a valve seat formed at the upper end opening of the valve chamber; a second spring with a weak elastic force, and an intermediary rod interposed between the second spring and the weight; the check valve is built into the separator; When the cylinder is tilted at a predetermined angle or more between the gas-liquid separation chamber and the vaporized fuel collection device, the weight slides and moves the needle valve in the closing direction via the intermediate rod. An evaporated fuel recovery device for a motorcycle, etc., characterized in that the device is activated by strongly pressing the device.