JPH0584833B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a fuel suction device for a fuel tank mounted on a vehicle such as an automobile.

Conventional technology Some automobile fuel tanks contain, for example,
As shown in Publication No. 57-109921, due to the structure of the part where the fuel tank is mounted, a bulge is formed inward on the bottom wall of the tank body. It is known to avoid interference between the bottom wall of the tank body and functional parts of the vehicle body.

Problem to be Solved by the Invention By forming a bulge in the bottom wall of the tank body, the main chamber and the sub-chamber are separated from each other in the substantially lower half of the tank body. In order to prevent fuel from remaining in either side, the feed pipe is branched into the main chamber side pipe and the auxiliary chamber side pipe through a switching valve, and when the fuel in the main chamber is consumed, the switching valve is closed. It must be activated so that the fuel in the pre-chamber is supplied. For this reason, not only is a switching valve required, but in order to automatically switch and operate this switching valve, a liquid level detection device is required in each of the main chamber and auxiliary chamber, a control unit is required, and an emergency It has been pointed out that there are problems with the product that make it expensive.

SUMMARY OF THE INVENTION Therefore, the present invention provides a fuel suction device for a fuel tank that does not require dedicated parts such as a switching valve or its operation control unit, and can efficiently supply fuel into the main chamber and the auxiliary chamber. be.

Means for solving the problem: The suction port of the feed pipe is arranged in the main chamber separated from the lower half of the tank body, and a chamber is formed at the end of the return pipe protruding into the tank body. A nozzle protruding into the chamber is formed at the end of the return pipe, and the nozzle is provided with a diffusion device for diffusing and ejecting fuel, and a constriction part is provided below the nozzle of the chamber, and a constriction part is provided below the nozzle of the chamber, and a constriction part is provided next to the constriction part. A tapered opening is formed and the tapered opening is disposed in the main chamber, while a communication pipe having one end opening disposed near the bottom of the auxiliary chamber is communicatively connected to the nozzle peripheral side of the chamber, and is connected to the chamber. A fuel suction device for a fuel tank comprising an ejector section at a connecting portion with a communication pipe, wherein the diffusion device includes a base section having a surface along the flow direction of fuel, and a fuel distributing device using this base section as a border. It is comprised of a wing section having a pair of diagonally downward facing surfaces in a direction that intersects each other, and an opening section provided in each wing section and opening toward the downstream side.

Operation When the feed pump is driven, fuel in the main chamber is sucked in from the suction port of the feed pipe and supplied to the fuel supply device, and excess supplied fuel is returned to the tank body via the return pipe. The surplus fuel returned from the return pipe is forcefully ejected from the nozzle in the ejector section due to the discharge pressure of the feed pump. This jetting of fuel creates negative pressure around the nozzle of the chamber.
The fuel in the auxiliary chamber is sucked into the chamber through the communication pipe, and together with the jet from the nozzle, the flow velocity is increased by the constriction section and fed into the main chamber through the tapered opening.

Here, by the diffusion device provided in the nozzle, the fuel ejected from the nozzle is diffused and injected in a cone shape onto the inner wall of the constriction section, etc. below the nozzle, and the air flows from the tapered opening following the constriction section. Prevent inhalation. Here, the fuel that has reached the diffuser is divided into two parts at the base piece and a swirling force is applied to each wing, but the flow velocity, which is weakened by the swirling force being applied, reaches the wings. A portion of the spilled fuel is compensated for by jetting downstream from the opening.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In Figures 1 and 2, 1 indicates the tank body;
An inwardly bulging portion 2 is formed approximately at the center of the bottom, and a main chamber 3 and a sub chamber 4 are separated from each other in approximately the lower half of the tank body 1. In the main chamber 3, a feed pump P is attached to the lower end of the feed pipe 5. For example, a filter 6 is disposed at the suction port of the feed pump P, and when the feed pump P is driven, the fuel in the main chamber 3 is Filter 6
The fuel is then passed through a feed pipe 5 to be fed to a fuel supply device, which will be described later. Reference numeral 7 denotes a return pipe which is disposed protrudingly within the tank body 1 and returns surplus fuel that is not consumed by the fuel supply device back into the tank body 1, and a chamber 9 is formed at the end of the return pipe 7. . A chamber 9 is provided at the end of the return pipe 7.
A nozzle 8 protruding inward is formed, and a constriction part 10 and a tapered opening 11 are formed below the nozzle 8 of the chamber 9, and this tapered opening 11 is connected to the main body. It is located in room 3.

Here, inside the nozzle 8, a swirling piece 100 is provided as a diffusion device that swirls and diffuses the fuel jetted from the tip of the nozzle 8.

As shown in FIGS. 3 to 9, this turning piece 100 includes a base piece 100a having a surface along the flow direction of fuel, and a pair that is divided with this base piece 100a as a boundary and facing diagonally downward. wing portions 100b with surfaces intersecting each other, and openings 10 provided in each wing portion 100b and open to the downstream side.
0c, and by arranging the base piece 100a on the upstream side, fuel can be swirled. Reference numeral 12 denotes a communicating pipe with one end opening 12a disposed near the bottom of the auxiliary chamber 4;
is communicated with and connected to the circumferential side of the nozzle 8 of the chamber 9, and an ejector portion 13 is formed at the connection portion between the chamber 9 and the communication pipe 12.

In this embodiment, the ejector part 13 is composed of an ejector main body 13a that integrates the chamber 9, the constriction part 10, and the taper opening 11, the nozzle 8, the port 7a of the return pipe 7, and the communication pipe 12.
The port 12b is formed into a unit with a lid 13b.

Further, an orifice 14 is provided at the upper side of the tapered opening 11, specifically at a location corresponding to the vicinity of the maximum liquid level of the main chamber 13.

According to the above embodiment structure, the feed pump P
When the main chamber 3 is driven, the fuel in the main chamber 3 is passed through the filter 6 and fed to the fuel supply device 15 through the feed pipe 5, as shown in FIG.

In this fuel supply device 15, not all of the fuel fed from the feed pipe 5 is consumed, and surplus fuel is returned into the tank body 1 via the return pipe 7.

Here, since the end of the return pipe 7 is formed as a nozzle 8 within the chamber 9 constituting the ejector section 13, the fuel is transferred from the nozzle 8 to the constricted section 10, the tapered opening 11, and the discharge pressure of the feed pump P. It is ejected forcefully towards. Therefore, a negative pressure is generated around the nozzle 8 in the chamber 9, and this negative pressure causes the fuel in the auxiliary chamber 4 to be sucked into the chamber 9 via the communication pipe 12.
Together with the jet from the nozzle 8, the flow velocity is increased by the constriction part 10, and the flow is fed into the main chamber 3 through the tapered opening 11, where an ejector action occurs and the sub-chamber 4
The fuel inside is transferred into the main chamber 3 along with the return of surplus fuel into the tank body 1.

Here, the fuel injected from the nozzle 8 is swirled within the nozzle 8 by the swirling piece 100 as shown in FIGS. Therefore, this cone-shaped jet spreads into the chamber 9.
The tapered opening 11 side of is closed. Here, the wing portion 100b of the turning piece 100 has an opening 10.
0c, this opening 100c
By jetting out a part of the fuel that has reached the wing portion 100b, the flow velocity of the fuel weakened by the application of swirling force is compensated for, and the fuel becomes easier to flow toward the nozzle 8. As a result, the negative pressure generated in the chamber 9 is not lost, and the communication pipe 1
Therefore, the suction force of the fuel is substantially increased compared to the case where the fuel is injected in a spot form from the nozzle 8, and the time for sucking up the fuel from the subchamber 4 is also shortened. I can do it. Then, the wing portion 100b of the base piece portion 100a of the turning piece 100
By changing the shape of the turning piece 100, such as by changing the angle of inclination with respect to the base piece 100a or adding more twist to the base piece 100a, various ejector characteristics can be obtained, and differences in tank capacity, return flow rate, etc. can be easily accommodated.

Once such a fuel transfer action occurs, even if the feed pump P stops, if the fuel level on the main chamber 3 side is lower than the fuel level on the auxiliary chamber 4 side, the communication pipe 12 is transferred from the chamber 9. Since the system is filled with fuel, the above-mentioned fuel transfer is continued due to the siphon effect until the fuel level on the main chamber 3 side becomes the same level as the fuel level on the auxiliary chamber 4 side. In the opposite case,
In other words, when the fuel level on the main chamber 3 side is higher than the fuel level on the auxiliary chamber 4 side, the siphon effect does not occur because the orifice 14 is located above the tapered opening 11 of the chamber 9. Therefore, main room 3
There is no backflow of fuel from the side to the subchamber 4 side. In FIG. 11, 16 indicates a fuel damper, 17 a fuel filter, and 18 a pressure regulator.

In the embodiment shown in FIG. 10, one end opening 12a of the communication pipe 12 is arranged in a swirl tank 19 fixed to the bottom wall of the subchamber 4. By arranging the opening 12a at one end of the communication pipe 12 in the turning tank 19 in this way, when the remaining fuel level becomes low, the fuel level can be adjusted to the dotted lines a and b in the same figure due to a sudden turn of the vehicle. Even when tilting as shown, the amount of fuel that can be sucked into the turning tank 19 can be secured, and even during this sharp turn, the above-mentioned transfer of fuel from the auxiliary chamber 4 side to the main chamber 3 side can be carried out. can continue.

In addition, when the feed pump P is arranged outside the tank body 1, the suction port of the feed pump P becomes the lower end of the feed pipe 5. In addition, in the embodiment described above, the tapered opening 11 of the chamber 9 is submerged in the fuel in the main chamber 3, but if the tapered opening 11 is placed above the fuel liquid level, there will be a hole above the tapered opening 11 to prevent backflow. There is no need to provide an orifice 14.

Effects of the Invention As explained above, according to the present invention, the fuel in the main chamber is led out to the fuel supply device by driving the feed pump, and at the same time, the fuel in the sub chamber is smoothly transferred to the main chamber side by the ejector action of the ejector part. Moreover, since it does not require special electrical parts unlike conventional methods, it is structurally simple and has a great practical effect of being able to achieve significant cost reductions. have

Furthermore, since a diffusion device is provided on the nozzle that protrudes into the chamber, the fuel ejected from the nozzle diffuses and closes the lower side of the chamber below the nozzle, thereby preventing air from being sucked in from the tapered opening. Therefore, the negative pressure generated in the chamber can be applied to the communication pipe without loss, and the fuel in the auxiliary chamber can be efficiently transferred to the main chamber. The diffusion device includes a base portion having a surface along the flow direction of the fuel, and a wing portion distributed with this base portion as a boundary and having a pair of surfaces facing diagonally downward in a direction crossing each other. , an opening provided in each wing section and open to the downstream side, the flow velocity of the fuel is weakened by the application of swirling force, and the fuel is ejected from the opening. This is compensated for by this, and the ejector action can be efficiently exerted.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is an overall sectional view, FIG. 2 is an enlarged sectional view of the main part of FIG. 1, FIG. 3 is a perspective view of the turning piece, and FIGS. 8 and 9 are a plan view and a front view showing the flow of fuel, respectively. FIG. 10 is a partial sectional view of another embodiment, and FIG. Figure 11 is a fuel supply system diagram. 1...Tank body, 2...Bulging part, 3...Main chamber, 4...Sub-chamber, 5...Feed pipe, 7...
Return pipe, 8... Nozzle, 9... Chamber, 10... Throttle part, 11... Taper opening, 1
2...Communication pipe, 13...Ejector part, 100
...Turning piece (diffusion device).

Claims (1)

[Claims] 1. In a structure in which a bulge is formed on the bottom wall of the tank body to separate a main chamber and a sub-chamber in substantially the lower half of the tank body, the suction port of the feed pipe is arranged near the bottom of the main chamber. At the same time, a chamber is formed at the end of the return pipe protruding into the tank body, a nozzle is formed at the end of the return pipe protruding into the chamber, and a diffusion device is provided for diffusing and ejecting fuel into the nozzle. a constriction section below the nozzle of the chamber, and a tapered opening section following the constriction section, and the tapered opening section is disposed within the main chamber, while the opening at one end is located near the bottom of the auxiliary chamber. A fuel suction device for a fuel tank, in which a disposed communication pipe is communicated and connected to a nozzle peripheral side of the chamber, and an ejector portion is configured at a connecting portion between the chamber and the communication pipe, wherein the diffusion device controls the flow of fuel. A base part having a surface along the direction, a wing part distributed with this base part as a border and having a pair of faces facing diagonally downward in a direction that intersects each other, and a wing part provided on each wing part and provided on the downstream side. 1. A fuel suction device for a fuel tank, characterized in that the fuel tank comprises: