JPH0350284Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to the piping structure of an evaporative system for automobiles, and particularly relates to a technique for preventing water from being sucked into the canister.

[Prior Art] In automobiles, it is required to maintain the internal pressure of the fuel tank by releasing vaporized gasoline generated within the fuel tank. On the other hand, from the viewpoint of air pollution, it is required that the amount of vaporized gasoline discharged to the outside be suppressed to an extremely low level. In response to these conflicting demands, conventional methods have been used to maintain the internal pressure of the fuel tank and suppress the amount of vaporized gasoline discharged by guiding the vaporized gasoline in the fuel tank to the canister and adsorbing it to an adsorbent inside the canister. The so-called canister type evaporation system is widely used.

FIGS. 3 and 4 are diagrams showing an example of such a canister type evaporation system.

In the evaporative system shown in Figures 3 and 4,
When the gasoline G in the fuel tank 1 is vaporized to produce vaporized gasoline g ₁ , this vaporized gasoline g ₁ is sent to the canister 3 via the pipe 2 and adsorbed by the activated carbon 4 housed in the canister 3 . It's becoming like that. The lower part of the canister 3 is connected via a drain hose 6 to a side member 5, which is a closed section of the vehicle body located below the canister 3, and air purified by the canister 3 is sent to the side member 5. It's becoming like that. In addition, if the outside temperature is high and the amount of vaporized gasoline g ₁ in the fuel tank 1 exceeds the adsorption capacity of the activated carbon 4 in the canister 3, the liquefied gasoline in the canister 3
g ₂ flows down from the lower part of the canister 3 into the side member 5 via the drain hose 6.

On the other hand, an intake manifold section 8 of the engine is connected to the upper part of the canister 3 via a control valve 7. When the engine is stopped, the control valve 7 is kept closed, as shown in FIG. Furthermore, when the engine is operating, the control valve 7 is opened by the vacuum pump ₉ as shown in FIG. The intake manifold portion 8 is configured to take in the outside air a from the intake manifold portion 8 together with the outside air a from the intake manifold portion 8.

[Problem to be solved by the invention] By the way, when a vehicle having an evaporative system as shown in FIG. may invade. In this way, when water enters from the side member 5, this water is sucked into the engine via the drain hose 6, canister 3, and control valve 7 by the suction force of the intake manifold section 8.
There is a problem that causes engine malfunction.

One possible solution to this problem is to connect the drain hose 6 to a position that is higher than the side member 5 and is not likely to be submerged in water. This causes a functional problem. On the other hand, a method of improving the watertight ability of the side member can be considered, but creating a completely watertight structure with a closed cross section is technically and economically wasteful and difficult, and is not practical.

The present invention was proposed in order to solve the shortcomings of the conventional technology, and the problem is to ensure sufficient air purification ability of the canister and discharge ability of liquefied gasoline within the canister, while still maintaining the vehicle body. To provide an excellent piping structure for an evaporative system for an automobile, which prevents water from entering the engine even when the lower part thereof is flooded.

[Means for Solving the Problems] The piping structure of the automotive evaporative system of the present invention communicates the lower part of the canister with a closed section of the vehicle body located below the canister through a communication member, and then connects the lower part of the canister or It is characterized in that the communication member communicates with the second closed section located at a higher position than the closed section through a ventilation member.

[Operation] In the present invention having the above configuration,
Even if the first closed section is submerged in water during operation of the engine, the second closed section located above is not submerged in water. Therefore, the suction force on the engine side acts as the suction force of vaporized gasoline in the canister and the suction force of outside air at the second closed cross section, and the suction force of water is not generated at the lower closed cross section, so that the engine This prevents water from entering the sides.

[Example] An example in which the present invention is applied to a one-box car will be specifically described below with reference to the drawings. Note that the same parts as those in the prior art shown in FIGS. 3 and 4 are given the same reference numerals.

First, as shown in FIGS. 1 and 2, the basic configuration of this embodiment is the same as that of the prior art shown in FIGS. 3 and 4. That is, vaporized gasoline g ₁ generated in the fuel tank 1 is sent to the canister 3 via the pipe 2, and the activated carbon 4 in the canister 3
It has become adsorbed by In addition, the lower part of the canister 3 is connected to a side member 5 which is a first closed cross-section through a drain hose (communication member) 6.
The liquefied gasoline g ₂ in the canister 3 is discharged. Further, an intake manifold part 8 on the engine side is connected to the upper part of the canister 3 via a control valve 7. When the engine is running, the control valve 7 is opened by the operation of the vacuum pump 9, and the intake manifold part 8 is connected to the canister. The suction force is working on 3.

In addition to the existing configuration as described above, in this embodiment, the bulk head reinforcement 10 at the rear of the cockpit is used as the second closed section located at a higher position than the side member 5. The rain force 10 and the central part of the drain hose 6 are connected through a ventilation hose (ventilation member) 11. In this case, the drain hose 6 is divided into an upper drain hose 12 and a lower drain hose 13 above and below the communication portion with the ventilation hose 11, and the diameter l ₁ of the ventilation hose 11 and the diameter l 1 of the upper drain hose 12 are separated. ₂ , and the diameter of the lower drain hose 13
The relationship between l ₃ is l ₂ > l ₁ > l ₃ . Thereby, the ventilation hose 11 and the lower drain hose 1
3 to the upper drain hose 12 is prevented from increasing.

The operation of this embodiment having the above configuration is as follows.
It is as follows.

First, when the engine is stopped, as shown in Fig. 1, the vaporized gasoline g ₁ in the fuel tank 1 is
It is fed into the canister 3 via the pipe 2 and adsorbed by the activated carbon 4 inside the canister 3. in this case,
The air purified by the canister 3 is sent to the ventilation hose 11 and the lower drain hose 13 via the upper drain hose 12, and then to the bulk head drain 10 and the side member 5.
and released to the outside. In addition, when the outside temperature is high and the amount of vaporized gasoline g ₁ in the fuel tank 1 exceeds the adsorption capacity of the activated carbon 4 in the canister 3, the liquefied gasoline g ₂ in the canister 3 is transferred to the upper and lower drain hoses 12. , 13 into the side member 5. Liquefied gasoline in this case g ₂
The emission effect is the same as before. Note that when the engine is stopped, the control valve 7 is maintained in a closed state and the intake manifold portion 8 and the canister 3 are separated, so that no suction force is applied to the canister 3.

Next, when the engine is running, the control valve 7 is opened by the vacuum pump 9 and the intake manifold section 8 is opened, as shown in FIG.
Due to the negative pressure effect, the vaporized gasoline g ₁ in the canister 3 is sucked into the intake manifold section 8 together with the outside air a from the ventilation hose 11 and the lower drain hose 13 .

By the way, in a conventional vehicle equipped with an evaporative system, when the lower part of the vehicle body is submerged in water, water is sucked in from the side member 5, causing water to enter the engine side, but in this embodiment,
Even if the side member 5 is submerged in water, the bulk head rainforest 10 located above the vehicle body is not submerged in water. Therefore, the suction force of the intake manifold section 8 is the suction force of the vaporized gasoline _g1 in the canister 3 and the bulk head reinforcement (second closed cross section).
It acts as a suction force for the outside air a at the side member 5, and does not generate a suction force for water at the side member 5. Therefore, it is possible to reliably prevent water from entering the engine side, and prevent the engine from malfunctioning due to water. Furthermore, since a watertight structure with a closed cross section is not required, it is effective in terms of structural simplification and cost savings.

Note that the present invention is not limited to the above-mentioned embodiments, and the first closed section connecting the drain hose (communication member) and the second closed section above this are connected to the side member and the bulkhead, respectively. The rain force is not limited and can be changed as appropriate.

[Effects of the invention] As explained above, in the piping structure of the automotive evaporation system of the invention, the ventilation member is communicated with the communication member between the canister and the lower first closed section in the existing configuration, and the ventilation member By improving the extremely simple configuration of communicating the canister with the second closed section, the canister can sufficiently purify the air and discharge the liquefied gasoline inside the canister, while also preventing the engine from leaking when the lower part of the vehicle is submerged in water. This provides an excellent effect in that water does not enter the engine, preventing engine malfunction, and there is no need for the first closed section to have a completely watertight structure.

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing one embodiment of the piping structure of an automobile evaporative system according to the present invention, in which FIG. 1 shows when the engine is stopped, FIG. 2 shows when the engine is running, FIG. 4 is a sectional view showing the piping structure of a conventional evaporative system for an automobile, with FIG. 3 showing the state when the engine is stopped, and FIG. 4 showing the state when the engine is operating. 1... Fuel tank, 2... Piping, 3... Canister, 4... Activated carbon, 5... Side member, 6...
...Drain hose, 7...Control valve,
8... Intake manifold section, 9... Vacuum pump, 10... Bulk head drain, 11... Ventilation hose, 12... Upper drain hose, 13... Lower drain hose.

Claims (1)

[Scope of Claim for Utility Model Registration] The vaporized gasoline in the fuel tank is guided to the canister and adsorbed to the adsorbent in the canister, and when the engine is running, a suction force is exerted from the engine side to the canister side due to the negative pressure effect to convert the vaporized gasoline to the canister. In an automobile equipped with an evaporation system that sucks outside air, a lower part of the canister is communicated with a first closed section of the vehicle body located below the canister through a communication member, and the lower part of the canister or the communication member is connected to the first closed section of the vehicle body located below the canister. A piping structure for an evaporative system for an automobile, characterized in that the piping structure is connected to a second closed section located at a higher position than the first closed section through a ventilation member.