JP2020152152A - Liquid tank - Google Patents

Abstract

To inhibit a liquid from being squirted from an inlet part of a filler pipe.SOLUTION: A liquid tank 1 includes: a tank body 2; a filler pipe 3 connected to the tank body and used to inject a liquid into the tank body; and a breather pipe 4 connected to the tank body and the filler pipe and used to discharge a gas in the tank body during injection of the liquid. The breather pipe includes: an inlet part 9 which is disposed facing downward in the tank body; and an opening 22 provided at a periphery side surface part 21 of the inlet part. A cross section area of the opening is reduced toward the upper side.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a liquid tank, and more particularly to a liquid tank suitable for storing a liquid such as a fuel for an internal combustion engine in a vehicle.

For example, in a vehicle, the fuel of an internal combustion engine, which is a liquid, is stored in a fuel tank as a liquid tank. The fuel tank includes a tank body which is a container for substantially storing fuel, a filler pipe for injecting a liquid into the tank body, and a breather pipe for discharging gas in the tank body when the liquid is injected. ..

JP-A-2009-262582

The outlet of the breather pipe is connected to the inlet of the filler pipe, and the gas passing through the breather pipe is released to the atmosphere from the outlet of the breather pipe via the inlet of the filler pipe.

Here, there is no particular problem when the flow rate of the fuel supplied to the filler pipe at the time of refueling is small. However, if the flow rate is high, the pressure of the gas in the tank body rises, and the fuel in the tank body is pushed out into the breather pipe. Then, there is a problem that the fuel flows back in the filler pipe after being discharged from the outlet portion of the breather pipe and is ejected to the outside from the inlet portion of the filler pipe.

Therefore, the present disclosure was conceived in view of such circumstances, and an object thereof is to provide a liquid tank capable of suppressing liquid from being ejected from an inlet portion of a filler pipe.

According to one aspect of the present disclosure
With the tank body
A filler pipe connected to the tank body and for injecting a liquid into the tank body,
A breather pipe connected to the tank body and the filler pipe for discharging gas in the tank body when a liquid is injected.
With
The breather pipe includes an inlet portion arranged downward in the tank body and an opening provided on a peripheral side surface portion of the inlet portion.
A liquid tank is provided, characterized in that the cross-sectional area of the opening decreases upward.

Preferably, the cross-sectional area of the opening is continuously reduced toward the top.

Preferably, the opening is a triangle having a base at the lower end of the entrance.

According to the present disclosure, it is possible to suppress the liquid from being ejected from the inlet of the filler pipe.

It is the schematic which shows a part of the fuel tank which concerns on embodiment of this disclosure. It is an enlarged view which shows the main part of a fuel tank. It is a figure which shows the decrease of the cross section of an opening. It is a figure which shows the 1st modification. It is a figure which shows the 2nd modification.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to the following embodiments.

FIG. 1 is a schematic view showing a part of the liquid tank according to the present embodiment. The liquid tank of the present embodiment is applied as a fuel tank 1 for storing fuel of an internal combustion engine (engine) in a vehicle, and the liquid to be stored is fuel. The vehicle is a large vehicle such as a truck, the internal combustion engine is a diesel engine, and the fuel is light oil. However, the type, application, etc. of the vehicle, internal combustion engine, and fuel are not particularly limited. For example, the vehicle may be a small vehicle such as a passenger car, the engine may be a gasoline engine, and the fuel may be gasoline. You may.

The engine may be mounted on a moving body other than a vehicle, for example, a ship, a construction machine, or an industrial machine. Further, the engine does not have to be mounted on a moving body, and may be a stationary engine.

The fuel tank 1 is connected to a tank body 2 which is a container for substantially storing fuel (not shown), a filler pipe 3 which is connected to the tank body 2 and for injecting fuel into the tank body 2, and a tank body 2. And a breather pipe 4 connected to the filler pipe 3 and for discharging the gas in the tank body 2 at the time of fuel injection.

The tank body 2 of this embodiment is made of resin. However, the material is arbitrary and may be made of metal.

The filler pipe 3 has an outlet portion 5 as one end portion inserted and fixed to the tank body 2 from the side, and extends upward (obliquely upward in the illustrated example) from the outlet portion 5. Further, the filler pipe 3 has an inlet portion 6 as the other end portion located above the outlet portion 5. The filler pipe 3 is supplied with fuel from the refueling nozzle Z inserted into the inlet portion 6 from the outside, guides the supplied fuel and discharges the supplied fuel into the tank body 2 from the outlet portion 5, and discharges the fuel into the tank body 2. Inject into 2. The filler pipe 3 is capable of efficiently injecting fuel by utilizing the head between the inlet portion 6 and the outlet portion 5.

Although optional, a tapered nozzle insertion pipe 7 is provided inside the inlet portion 6 of the filler pipe 3 to insert and position the refueling nozzle Z and prevent fuel from blowing back as much as possible. A filler cap 8 is detachably attached to the inlet portion 6 of the filler pipe 3.

The breather pipe 4 has an inlet portion 9 as one end portion inserted and fixed to the tank body 2 from above, and extends upward (obliquely upward in the illustrated example) from the inlet portion 9. Further, the breather pipe 4 has an outlet portion 10 as the other end portion located above the inlet portion 9. The outlet portion 10 is connected to the inlet portion 6 of the filler pipe 3 on the outer peripheral side of the nozzle insertion pipe 7. The breather pipe 4 has a smaller diameter than the filler pipe 3 and has a circular cross section. For example, the inner diameter of the filler pipe 3 is about 30 to 40 mm, and the inner diameter of the breather pipe 4 is about 12 mm.

The breather pipe 4 may also be referred to as a breather tube, a vent pipe, a vent tube, or the like.

FIG. 2 shows in detail the main parts of the fuel tank 1. As shown in the figure, the breather pipe 4 is divided into three parts in the longitudinal direction, and the inlet portion 9 formed of the L-shaped pipe, the outlet portion 10 formed of the same L-shaped pipe, and these inlet portions 6 It also has an intermediate portion 11 that connects the outlet portion 10.

The intermediate portion 11 is formed by a flexible hose. The inlet end portion of the intermediate portion 11 is closely fitted to the outside of the inlet portion 9, and is tightened and fixed from the outer peripheral side by the fastening band 12. Similarly, the outlet end portion of the intermediate portion 11 is closely fitted to the outside of the outlet portion 10, and is tightened and fixed from the outer peripheral side by the fastening band 12. Other methods are also possible for connecting the intermediate portion 11. For example, when connecting the intermediate portion 11 to the inlet portion 9, a connection method using a quick connector or a connection method by press fitting can also be adopted.

The inlet portion 9 has a vertical portion 13 located on the inlet side thereof and extending in the vertical direction, and a horizontal portion 14 located on the outlet side thereof and curved from the upper end of the vertical portion 13 and extending in the horizontal direction or the horizontal direction. The lateral portion 14 is located outside the tank body 2, and the inlet end portion of the intermediate portion 11 is connected.

An insertion hole 15 is provided in the upper surface portion 2A of the tank body 2, and the vertical portion 13 of the inlet portion 9 is inserted into the insertion hole 15 from above. A mounting flange 16 is fixed to the outer peripheral portion of the vertical portion 13, and the mounting flange 16 is fixed to the upper surface portion 2A of the tank body 2 so that the inlet portion 9 is fixed to the tank body 2.

In the present embodiment, the inlet portion 9 and the mounting flange 16 are made of the same resin as the tank body 2. The mounting flange 16 has a shape like an inverted ring plate, and is integrally molded on the outer peripheral portion of the vertical portion 13. Further, the lower end surface 17 of the mounting flange 16 is integrally fixed to the upper surface portion 2A of the tank body 2 by heat welding or the like. As a result, the inlet portion 9 is fixed to the tank body 2 while preventing fuel leakage and gas leakage from the tank body 2.

If the tank body 2, the inlet 9, and the mounting flange 16 are made of metal, the mounting flange 16 is welded to the inlet 9 and the tank body 2.

When the inlet portion 9 is fixed in this way, the lower half portion of the vertical portion 13 is arranged downward in the tank body 2. That is, the inlet portion 9 is arranged in the tank main body 2 with the circular inlet opening 19 (see FIG. 3A) located at the lower end 18 thereof facing downward. As shown in FIG. 1, the height position H2 of the lower end 18 to the inlet opening 19 is higher than the height position H1 of the upper end of the outlet opening 20 of the filler pipe 3. The lower end 18 is perpendicular to the axial direction of the vertical portion 13.

In addition, in the present embodiment, an opening 22 is provided in the peripheral side surface portion 21 of the vertical portion 13 arranged in the tank main body 2. The cross-sectional area of the opening 22 decreases toward the upper side, and particularly continuously decreases in the present embodiment.

In the present embodiment, the opening 22 is a triangle having a base at the position of the lower end 18 of the vertical portion 13, particularly an isosceles triangle, and extends upward from the position of the lower end 18 of the vertical portion 13. The opening 22 has a shape such that the peripheral side surface portion 21 is cut out upward from the lower end 18 of the vertical portion 13, and communicates with the entrance opening 19 at the position of the lower end 18. The opening 22 has a predetermined apex angle θ and a pair of hypotenuses 24 extending obliquely upward from the lower end 18 and intersecting at the apex 23.

3 (A) to 3 (C) show the cross section (cross section) of the vertical portion 13 at each height position Ha, Hb, Hc which increases in order from the bottom. The lowest height position Ha is the height position at the lower end 18 (Ha = H2). The highest height position Hc is the height position near the top 23, and Hb is the height position in between. Note that FIG. 3A shows a state when the lower end 18 is viewed from below.

The cross-sectional area of the opening 22 means, for example, in the case of FIGS. 3A to 3C, the areas Aa, Ab, and Ac of the portion representing the opening 22. As can be seen from this figure, the cross-sectional area of the opening 22 is continuously reduced toward the upper side. Further, the width W of the opening 22 is also continuously reduced toward the upper side.

The rate at which the cross-sectional area of the opening 22 decreases with respect to the height from the lower end 18, that is, the cross-sectional area reduction rate can be changed according to the size of the apex angle θ. For example, if the apex angle θ is increased, the cross-section reduction rate can be increased, and conversely, if the apex angle θ is decreased, the cross-section reduction rate can be reduced.

By the way, assuming a comparative example without an opening 22, this comparative example has the following problems.

As shown in FIG. 1, for example, when refueling an empty fuel tank 1 to a full tank, the refueling nozzle Z of the refueling gun is inserted into the nozzle insertion pipe 7 at the inlet 6 of the filler pipe 3 to start refueling.

The liquid level in the tank body 2 gradually rises, and eventually the liquid level reaches the height position H1 at the upper end of the outlet opening 20 of the filler pipe 3. In that case, the outlet opening 20 of the filler pipe 3 is closed with fuel. After that, the liquid level rises in the tank body 2 and in the filler pipe 3. At this time, the gas (referred to as the gas in the tank) in the space above the liquid level (referred to as the space in the tank) in the tank body 2 is released to the atmosphere through the breather pipe 4. Here, the gas in the tank is a mixture of air and fuel vapor.

Specifically, as the liquid level rises, the gas in the tank is pushed into the breather pipe 4 from the inlet 9 of the breather pipe 4. The gas in the tank pushed in rises in the breather pipe 4, and is discharged from the outlet portion 10 into the inlet portion 6 of the filler pipe 3. Then, the gas in the tank flows through the gap between the nozzle insertion pipe 7 and the refueling nozzle Z in the reverse flow direction opposite to the refueling direction, and is discharged from the inlet portion 6 of the filler pipe 3 to the atmosphere.

After that, the liquid level reaches the height position H2 of the lower end 18 of the inlet portion 9 of the breather pipe 4, as shown in FIG. In that case, the inlet opening 19 of the breather pipe 4 is closed with fuel.

Here, it is assumed that the flow rate of the fuel supplied to the filler pipe 3 is sufficiently small (that is, the refueling rate is sufficiently slow). In this case, after the inlet opening 19 of the breather pipe 4 is closed with fuel, the rise of the liquid level in the tank body 2 stops. Instead, the fuel penetrates into the breather pipe 4 through the inlet opening 19 and the liquid level rises in the filler pipe 3 and in the breather pipe 4. As the liquid level in the breather pipe 4 rises, the gas in the tank above the liquid level is pushed upward and released to the atmosphere.

When the liquid level reaches the height position H3 of the fuel detection sensor (for example, pressure sensor) S attached to the tip of the refueling nozzle Z, refueling is automatically stopped. Since this height position H3 is sufficiently lower than the outlet opening 25 of the breather pipe 4, fuel discharge from the outlet portion 10 of the breather pipe 4 into the filler pipe 3 is prevented.

However, if the flow rate of the fuel supplied to the filler pipe 3 is large (that is, the refueling speed is high), the following problem may occur. Immediately after the liquid level reaches the height position H2 and the inlet opening 19 of the breather pipe 4 is closed with fuel, the rise in the liquid level in the tank body 2 should stop, but the fuel flow rate is high. Therefore, the liquid level rises slightly, the gas in the tank in the tank body 2 is compressed, and the pressure of the gas in the tank rises sharply. As a result, the gas in the tank rapidly pushes the fuel in the tank body 2 into the breather pipe 4. Then, the extruded fuel soars in the breather pipe 4, and is ejected from the inlet portion 6 of the filler pipe 3 to the outside at substantially the same timing as, for example, when the refueling is automatically stopped.

That is, the fuel that has risen sharply in the breather pipe 4 is discharged from the outlet portion 10 into the inlet portion 6 of the filler pipe 3, and then in the nozzle insertion pipe 7 and the refueling nozzle Z, as in the above-mentioned gas discharge path. Through the gap, it flows in the reverse flow direction opposite to the refueling direction, and is ejected from the inlet portion 6 of the filler pipe 3 to the outside.

Note that this fuel ejection occurs when (i) the breather pipe 4 has a smaller diameter than the filler pipe 3 and the fuel rising speed tends to increase, and (ii) the filler pipe 3 becomes long or has a complicated shape due to the vehicle layout. Another cause is that the fuel rising speed in the filler pipe 3 is difficult to increase.

Therefore, in the present embodiment, in order to suppress or prevent such fuel ejection, an opening 22 is provided at the inlet 9 of the breather pipe 4. In this case, the following effects can be obtained. It is assumed that the flow rate of the fuel supplied to the filler pipe 3 is large.

Even immediately after the liquid level reaches the height position H2 and the inlet opening 19 of the breather pipe 4 is closed with fuel, the space inside the tank above the liquid level in the tank body 2 remains through the opening 22 through the breather pipe. It communicates with the inside of 4. Therefore, even if the liquid level rises slightly above the height position H2, the gas in the tank can escape into the breather pipe 4 through the opening 22, so that the compression and pressure rise of the gas in the tank can be suppressed. it can. As a result, it is possible to suppress or prevent the fuel from being pushed out into the breather pipe 4 and being ejected from the inlet portion 6 of the filler pipe 3 to the outside.

However, if the escape of the gas in the tank through such an opening 22 is allowed, the liquid level in the tank body 2 is also allowed to rise, and as a result, the position of the inlet opening 19 of the breather pipe 4 is moved upward. It will be the same as moving, and there is a risk of hindering the planned fuel rise in the filler pipe 3 and the automatic stop of refueling.

Therefore, in the present embodiment, the cross-sectional area of the opening 22 is reduced toward the upper side. In this way, as the liquid level rises from the height position H2, the area of the substantial opening 22 that communicates the space inside the tank with the inside of the breather pipe 4 can be reduced. Then, it is possible to make it difficult for the gas in the tank to escape as the liquid level rises, and to make it easier to raise the pressure of the gas in the tank. As a result, it becomes possible to realize the planned fuel rise in the filler pipe 3 and automatic refueling stop.

At this time, it is convenient because the method of increasing the pressure with respect to the increase of the liquid level can be changed according to the magnitude of the apex angle θ.

As described above, in the present embodiment, since the opening 22 whose cross-sectional area decreases toward the upper side is provided, at the same time when the liquid level reaches the height position H2, the space inside the tank and the inside of the breather pipe 4 are communicated with each other. The communication area can be gradually reduced as the liquid level rises from the height position H2, rather than immediately shutting off. As a result, the pressure rise of the gas in the tank after the liquid level reaches the high position H2 can be suppressed, and the fuel is ejected from the inlet portion 6 of the filler pipe 3 even when the refueling speed is high. Refueling can be reliably and automatically stopped. Therefore, it is possible to prevent the fuel from being ejected from the inlet portion 6 of the filler pipe 3.

Next, a modified example of this embodiment will be described. The same parts as those in the basic embodiment are designated by the same reference numerals in the drawings, and the description thereof will be omitted. Hereinafter, the differences from the basic embodiment will be mainly described.

In the first modification shown in FIG. 4, the shape of the opening 22 is changed to a right triangle. The opening 22 is a right triangle having a base at the position of the lower end 18 of the vertical portion 13, and extends upward from the position of the lower end 18 of the vertical portion 13. The opening 22 has a predetermined apex angle θ, a apex 23, a vertical side 26 extending vertically upward from the lower end 18, and a hypotenuse 27 intersecting the vertical side 26 at the apex 23.

The cross-sectional area of the opening 22 is also continuously reduced toward the upper side. Therefore, this modified example exerts the same action and effect as the basic embodiment.

In the second modification shown in FIG. 5, the opening 22 is formed by a plurality of holes 28 instead of notches. And the number of holes 28 decreases toward the top. Therefore, the cross-sectional area of the opening 22 of this modification is reduced toward the upper side, and in particular, it is generally gradually reduced. Even with such a modified example, it is possible to exert substantially the same effect as that of the basic embodiment. The cross-sectional area of the opening 22 as used herein means the total area of one or more holes 28 in a specific cross section.

This is just an example, but in the case of this modified example, five holes 28 are arranged side by side in a row at the bottom. The number of holes 28 is reduced one by one as the row goes up. The number of holes 28 in the uppermost stage is one, and the total number of stages is five. The holes 28 are circular and are arranged in a staggered pattern. The dimensions of the holes 28 are all the same.

However, the number of holes 28, the number of steps, the arrangement method, the shape, the dimensions, and the like can be arbitrarily changed.

Although the embodiments of the present disclosure have been described in detail above, various other embodiments and modifications of the present disclosure can be considered.

(1) For example, the present disclosure is applicable to a liquid tank other than the fuel tank, which stores a liquid other than the fuel. For example, some vehicles equipped with a diesel engine are equipped with an SCR (Selective Catalytic Reduction) device for reducing and purifying NOx in exhaust gas. Liquid urea water is used as a reducing agent in the SCR device, and a urea water tank for storing the urea water is mounted on the vehicle. When the urea water is injected into the urea water tank, the same urea water as described above may be ejected. In this case, the present disclosure can be applied to the urea water tank to suppress the ejection of urea water.

(2) The shape of the opening may be a shape other than a triangle, for example, a semicircle or the like, as long as the cross-sectional area decreases toward the upper side.

The embodiments of the present disclosure are not limited to the above-described embodiments, and all modifications, applications, and equivalents included in the ideas of the present disclosure defined by the scope of claims are included in the present disclosure. Therefore, the present disclosure should not be construed in a limited manner and may be applied to any other technique belonging within the scope of the ideas of the present disclosure.

1 Fuel tank 2 Tank body 3 Filler pipe 4 Breather pipe 9 Inlet 21 Peripheral side surface 22 Opening

Claims (3)

With the tank body
A filler pipe connected to the tank body and for injecting a liquid into the tank body,
A breather pipe connected to the tank body and the filler pipe for discharging gas in the tank body when a liquid is injected.
With
The breather pipe includes an inlet portion arranged downward in the tank body and an opening provided on a peripheral side surface portion of the inlet portion.
A liquid tank characterized in that the cross-sectional area of the opening decreases toward the top. The liquid tank according to claim 1, wherein the cross-sectional area of the opening is continuously reduced toward the upper side. The liquid tank according to claim 1 or 2, wherein the opening is a triangle having a base at a position at the lower end of the inlet.

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