JP2500901Y2 - Fuel tank device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a fuel tank device, and more particularly, to a fuel tank device in which a fuel tank is partitioned at least in a lower portion.

(Prior Art) Conventionally, the lower part of the fuel tank is partitioned, for example, Nissan Service Weekly Report No. 588 (September 1987).
Monthly issue publisher: Nissan Motor Co., Ltd.) The one described on page B-125 is known.

As shown in FIG. 5, in this device, a fuel tank 01 is divided into a main tank portion 02 and a sub tank portion 03, and a jet pump 04 for transferring the fuel in the sub tank portion 03 to the main tank portion 02 is provided. There is.

The jet pump 04 has a structure in which the flow of the return fuel from the engine 05 is used to suck up the fuel in the sub tank portion 03.

(Problems to be solved by the invention) In a fuel tank device having such a jet pump, in order to prevent the fuel in the main tank portion from flowing backward to the sub tank side through the fuel transfer path of the jet pump when the engine is stopped. It is necessary to arrange the jet pump at a position higher than the part that divides both tank parts.

In such cases, it is necessary to open and connect a filler tube for injecting fuel to a position higher than the jet pump as a measure to prevent the fuel from being blown out when the internal pressure in the fuel tank rises due to the stirring action of the jet pump. ,
There is a problem in that the degree of freedom in design is reduced due to such restrictions.

The present invention has been made in view of the above problems, and it is an object of the present invention to prevent fuel agitation by a jet pump and increase the degree of freedom of a filler tube connection position.

(Means for Solving the Problems) In order to solve the above problems, in the fuel tank device of the present invention, the vehicle body is provided with a fuel tank having at least a lower part partitioned into a sub tank part and a main tank part. A filler tube opening for fuel injection is provided inside, and a fuel pump that sends fuel to the engine and a flow of return fuel from the engine are used to suck in and discharge fuel inside the sub tank in the main tank. A jet pump for supplying from the outlet to the main tank part is provided, an enclosing member that covers the periphery of the discharge port of the jet pump, and has a discharge opening part at the bottom is provided, and the discharge opening part is a filler tube opening part. The means is arranged below the upper end of the.

(Operation) When the engine is driven, the flow of the return fuel from the engine causes the jet pump to suck the fuel in the sub tank portion and transfer it to the main tank portion.

In this case, since the surrounding member is provided around the discharge port of the jet pump, when the liquid level of the fuel in the main tank is above the discharge opening of the surrounding member, the surrounding member agitates the fuel. Is prevented, the generation of gasoline vapor is suppressed, and the internal pressure of the fuel tank can be prevented from rising.

This effect of preventing the internal pressure from rising is obtained until the fuel liquid level in the main tank portion becomes lower than the discharge opening portion of the surrounding member.

Therefore, if the upper end of the filler tube opening is arranged at a position higher than the discharge opening of the surrounding member, even if the filler tube opening is arranged at a position lower than the discharge opening of the jet pump, there is a risk of fuel blowout. There is no.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.
In the description of the embodiments, the same reference numerals indicate the same objects in each drawing.

 First, the configuration will be described.

FIG. 1 is a sectional view showing the overall construction of a fuel tank device according to a first embodiment of the present invention, in which 1 is a fuel tank. The lower part of this fuel tank 1 is a sub tank part 11
And the main tank portion 12 are divided.

 Incidentally, G indicates the liquid surface of the fuel.

A filler tube 3 is connected to the main tank portion 12, and a filler tube opening portion 32 which is an opening end of the filler tube 3 is formed.

The fuel tank 1 is provided above the filler tube 3.
The pressure relief pipe 33 communicated with the upper part of the.

A fuel pump 4 and a jet pump 7 are provided inside the main tank portion 12.

The fuel pump 4 supplies the fuel in the main tank portion 12 to the engine 9 through the feed tube 6, and is provided with a filter 41 on the suction side.

The jet pump 7 uses the flow of the return fuel flowing from the engine 9 through the return tube 5 to suck the fuel in the sub tank portion 11 by the pump tube 71 extending to the bottom portion in the sub tank portion 11 and discharge it. It is discharged from the outlet 72 and transferred to the main tank section 12.

A silencer 73 is provided at the discharge port 72 of the jet pump 7.
And the surrounding member 8 is attached. This structure is shown in detail in the enlarged sectional view of FIG.
Reference numeral 73 is for canceling the jetting noise of fuel from the discharge port 72, and is formed of a mesh member.

The surrounding member 8 is provided so as to cover the periphery of the discharge port 72 and the silencer 73. This surrounding member 8
Is formed in a shape in which the lower end of the cylinder is narrowed, and a discharge opening 81 is formed at the lower end so as to open downward.

The upper end of the surrounding member 8 communicates with the fuel tank 1 side.

Further, as shown in FIG. 1, the discharge opening 81 of the surrounding member 8 is arranged at a position lower than the upper end h of the filler tube opening 32. The filler tube 3 is provided with a fuel cap (not shown).

Next, the operation of the fuel tank device of the embodiment will be described.

When the engine 9 is driven and the pump 4 supplies fuel,
The fuel not consumed from the engine 9 is sent back through the return tube 5.

Then, in the jet pump 7, the flow of the return fuel is used to suck the fuel in the sub tank portion 11,
Discharge from the discharge port 72 to the main tank unit 12.

Therefore, even if the lower portion of the fuel tank 1 is partitioned, the fuel in the sub tank portion 11 can be consumed.

 Next, the operation of the surrounding member 8 will be described.

(A) Above the fuel level G The fuel discharged from the discharge port 72 of the jet pump 7 is
After being silenced by the silencer 73, it is discharged to the inner peripheral surface of the surrounding member 8 and supplied to the main tank portion 12 from the discharge opening 81 at the lower end of the surrounding member 8.

Therefore, when the fuel liquid level G is located above the discharge opening 81 of the enclosing member 8, the fuel in the fuel tank 1 is prevented from being stirred by the fuel discharged from the jet pump 7.

Therefore, the generation of gasoline vapor due to fuel agitation is suppressed, and the internal pressure of the fuel tank 1 is prevented from rising.

FIG. 3 shows this internal pressure rise prevention action. In FIG. 3, the left vertical axis shows the internal pressure P of the fuel tank, the right vertical axis shows the fuel temperature T, and the horizontal axis shows the passage of time. The range of A on the axis indicates when the vehicle is running, and the range of B indicates the time when idling.

The solid line in the figure shows the change in the fuel temperature, the alternate long and short dash line shows the change in the tank internal pressure when the surrounding member 8 is not provided, and the dotted line shows the tank internal pressure in the dotted line of the fuel tank device of the present embodiment. .

As shown in this figure, in the idling state where the fuel consumption in the engine 9 is reduced, the effect of preventing the internal pressure rise is particularly remarkable.

(B) When the fuel level G drops When the fuel level G falls to a position lower than the discharge opening 81, the fuel stirring function of the surrounding member 8 is lost, and the fuel discharged from the discharge opening 81 causes the fuel tank ( The fuel in the main tank portion 12) 1 is agitated and gasoline vapor is generated, so that the internal pressure of the fuel tank rises. At this time, the fuel level G is the upper end portion h of the filler tube opening 32.
Since it is located at a lower position than that (the upper end portion h is located higher than the discharge opening portion 81), fuel is not blown out even when the fuel cap is opened.

Next, a second embodiment of the present invention shown in FIG. 4 will be described.

In this embodiment, the discharge opening 81 of the surrounding member 8 is filtered.
This is an example in which the height from the bottom is H near 41.

Since the other structure is the same as that of the first embodiment, its explanation is omitted.

Therefore, in the second embodiment, the internal pressure is prevented from rising while the fuel liquid level G is higher than the height of H from the bottom, and the upper end h of the filler tube opening 32 is at this H level.
If it is at a higher position than this, it is possible to prevent fuel from blowing out.

Therefore, the degree of freedom of the mounting position of the filler tube 3 is higher than that of the first embodiment.

Further, the return fuel discharged from the discharge opening 81 has a characteristic that light components are evaporated due to the temperature rise on the engine 9 side and vapor is hard to be generated. Now, let this discharge opening 81 be the filter 41
Since the fuel pump 4 is disposed in the vicinity of the above, fuel having such good characteristics is easily supplied from the fuel pump 4 to the engine 9, and vapor lock is less likely to occur.

Although the embodiment has been described above with reference to the drawings, the specific configuration is not limited to this embodiment. For example, in the embodiment, the lower portion of the fuel tank is divided into a sub tank portion and a main tank portion. However, the sub and main tank parts may be completely divided into two.

Further, in the embodiment, the example in which the silencer is provided inside the surrounding member is shown, but this silencer may not be provided.

(Effects of the Invention) As described above, in the fuel tank device of the present invention, the periphery of the discharge port of the jet pump is covered with the surrounding member, so that the fuel liquid level in the main tank is the discharge opening of the surrounding member. The effect of being able to prevent the internal pressure of the fuel tank from rising is obtained until it falls below the lower part, and due to this effect, the upper end of the filler tube opening is arranged above the discharge opening of the lower end of the surrounding member. If so, the filler tube opening can be arranged at a position lower than the discharge port of the jet pump, and the degree of freedom in setting the position of the filler tube is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing the overall construction of a fuel tank device according to a first embodiment of the present invention, FIG. 2 is an enlarged sectional view showing the essential parts of the device of the embodiment, and FIG. 3 is a first embodiment and a conventional example. 4 is a graph showing a change in internal pressure, FIG. 4 is a sectional view showing an essential part of a fuel tank device according to a second embodiment of the present invention, and FIG. 5 is a sectional view showing a prior art. 1 …… Fuel tank 11 …… Sub tank 12 …… Main tank 3 …… Filler tube 32 …… Filler tube opening 4 …… Fuel pump 7 …… Jet pump 72 …… Discharge port 8 …… Enclosure 81… … Discharge opening 9 …… Engine

Claims (1)

(57) [Scope of utility model registration request] 1. A vehicle body is provided with a fuel tank at least a lower part of which is divided into a sub tank part and a main tank part, and a filler tube opening for fuel injection is provided in the fuel tank. A fuel pump that sends fuel to the engine and a jet pump that sucks the fuel in the sub-tank part and supplies it from the discharge port to the main tank part by using the flow of the return fuel from the engine are provided in the part. A fuel tank device characterized in that an enclosing member that covers the periphery of the discharge port and has a discharge opening portion at a lower portion is provided, and the discharge opening portion is arranged at a position lower than an upper end of the filler tube opening portion. .