JPH0445666B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fuel unit, in which the fuel pump operates to supply fuel to an engine to reduce the fuel in a sub-tank and depressurize the interior of the sub-tank. In conjunction with this, a sub-tank is used which allows a negative pressure to be created inside the sub-tank by sucking fuel from the bottom of the fuel tank using a replenishment tube and replenishing the sub-tank. In addition to automatically and intermittently discharging fuel into the fuel tank by jetting it into the compartment inside the sub-tank, it can also be used in the sub-tank of new cars, etc., where there is no way to create negative pressure in the sub-tank and the fuel has not been refilled. This is what I did.

(Prior art) It is possible to provide a sub-tank in a fuel tank that allows for negative pressure inside the fuel tank, or to provide a refueling tube with a pipe end facing the bottom of the fuel tank in a sub-tank capable of negative pressure. No known configuration is known, such as providing a device for intermittently discharging fuel gas that collects in the upper layer of an empty sub-tank capable of negative pressure into the fuel tank.

(Problems to be Solved by the Invention/Objectives of the Invention) The fuel pump unit is made of a new material called a sub-tank that enables negative pressure in the interior, and the jet fuel flowing from the jet tube into the compartment of the sub-tank The solution is to make it possible to forcefully and intermittently discharge the fuel gas that collects in the upper layer of the sub-tank into the fuel tank, and to also be able to deal with new cars that do not have a means to create negative pressure inside the sub-tank. This is the goal of the present invention.

(Means for Solving the Problems) The present invention has been made to meet the above-mentioned object, and a specific invention is to provide a sub-tank in a fuel tank with a negative pressure inside the fuel tank, and to provide an end portion of the sub-tank to the sub-tank. A replenishment tube facing the bottom of the fuel tank and equipped with a check valve opened by the pressure of fuel in the fuel tank near the bottom of the sub-tank, and a fuel pump connected to the engine are installed, and a compartment is provided in the sub-tank. A fuel jet tube is inserted into the chamber from above, and the compartment is turned into a fuel reservoir with a device that stores a substantially constant amount of jet fuel and intermittently flows out to the sub-tank, and the jet fuel in the compartment is A first check valve that is pushed by the fuel gas pressure in the sub-tank and opens the valve toward the compartment to discharge gas at a position exceeding the height at which intermittent outflow starts, and the fuel gas pressure in the compartment. A second check valve is provided that opens the valve on the fuel tank side when pushed and discharges gas, and the fuel pump supplies fuel to the engine to create a negative pressure in the subtank and refuel from the fuel tank using the replenishment tube. It is characterized by allowing
The second invention is characterized in that the jet tube of the specific invention is a return tube. A third invention is characterized in that the jet tube of the specific invention is a branch tube that is provided on the discharge side of the fuel pump and discharges a part of the fuel. The fourth invention is a siphon device that stores a substantially constant amount of jet fuel in a compartment and intermittently flows out into a sub-tank according to the specified invention. It is characterized by certain things.

(Example) Figures 1 to 6 show the first example of the present invention, and the seventh
The figure shows the second embodiment.

In the first embodiment shown in FIGS. 1 to 6, 1 is a fuel tank, 3 is a sealing lid provided on a working hole 2 of the fuel tank 1 to prevent fuel leakage, and a replenishment tube 5, which will be described later, is provided on the bottom surface of the lid. A sub-tank 4 is provided in which the fuel supply pipe 7 of the fuel pump 6 and the return tube 8, which is an example of the fuel jet tube of the present invention, are sealed jointly with the sealing lid 3 or sealed alone to enable negative pressure inside the tank. establish.

The replenishment tube 5 has a bag-shaped filter 11 that protrudes from the bottom of the sub-tank 4 and is attached to the end thereof, and is in contact with the bottom of the center of the fuel tank 1. When the sub-tank 4 cannot be attached to the center of the fuel tank 1, The substantially horizontal bent portion of the replenishment tube 5 protruding from the bottom of the sub-tank 4 is extended to the center of the bottom of the fuel tank 1, and the filter 11 is attached. The replenishment tube 5 is formed inside the sub-tank 4 into an inverted T-shape consisting of a horizontal portion 12 and a vertical portion 13, and a check valve 14 is provided at the end of the horizontal portion 12 to prevent backflow of fuel into the fuel tank 1. As shown in FIG. 3, the check valve 14 is made of rubber or the like and has a valve port 15 at its tip that is elastically closed. When the fuel tank 1 is filled with fuel, the pressure chamber automatically causes the fuel to flow into the sub-tank 4, and prevents it from flowing back from the sub-tank 4 to the fuel tank 1, thereby preventing leakage from the check. Use something that is almost zero.

The vertical portion 13 has a tube shape with an opening 5a at the upper portion of the sub-tank 4.

A compartment 16 is provided inside one wall of the sub-tank 4, which allows negative pressure in the interior, and a return tube 8 is faced from the upper wall of the compartment.

The compartment 16 has a deep box shape, and is provided with a device that forms a fuel reservoir 17 for jet fuel from the return tube 8 and intermittently flows out to the sub-tank 4 when a substantially constant amount of jet fuel is accumulated in the reservoir 17. In this embodiment, a siphon device 18 is installed on the side wall of the compartment 16, and the accumulated jet fuel from the return tube 8 starts to flow out to the sub-tank 4 side when the liquid level reaches a substantially constant level. An embodiment is shown in which the device is provided as a device that stores a substantially constant amount of jet fuel and intermittently flows out into the sub-tank 4. The siphon device 18 has a downward inner opening 19 near the bottom of the compartment 16 (fuel reservoir 17), and on the side of the sub-tank 4 outside the compartment 16, a first
It has a bend 20 and a second bend 21 that rises from the bend 20 to near the upper end of the tank 4, so that the heights of the downwardly directed outer opening 22 and the above-mentioned inner opening 19 are approximately the same.

As shown in FIG. 5, the compartment 16 is pushed open by the pressure of the fuel gas on the sub-tank 4 side to a position exceeding the height at which the jet fuel X from the siphon device 18 starts flowing out, and the gas is released. A guide cylinder is provided with a first check valve 25 that allows entry into the farm room 16, and further closes the valve port 27 by pushing up the float valve 26 by the jet fuel X that flows into the farm room 16 and accumulates from the position where it starts to accumulate. The outer end of 28 is opened at a high position in the fuel tank 1, and a second check valve 30 is provided at the opening.

The fuel pump 6 is mounted on a mounting base 29 provided within the sub-tank 4. The opening 6a in the sub-tank 4 of the suction tube of the fuel pump and the check valve 1
It is preferable to set the height to approximately the same level as 4.

In this embodiment, when the fuel tank 1 is filled with fuel F 1 when the car is new, there is no means to make the sub tank ₄ negative pressure, and the sub tank 4 is not refilled with fuel F 1 , the sub tank 4
Due to _the pressure difference between Fuel is supplied to the engine, and jet fuel X is spouted from the return tube 8 into the compartment 16.

Even with exceptions such as new cars, fuel tank 1
is filled with fuel F, when the fuel pump 6 is started and the fuel F ₁ in the sub-tank 4 is supplied to the engine, the sub-tank 4 reduces the volume corresponding to the amount of fuel supplied and becomes negative pressure. Fuel F in the fuel tank 1 is sucked into the sub-tank 4 by the replenishment tube 5 due to negative pressure.

When fuel is supplied to the engine and the jet fuel The pressure in the upper layer increases and closes the first check valve 25. The fuel gas in the compartment 16 is discharged into the fuel tank 1 by pushing the second check valve 30 by the gas pressure (the fuel tank has a device for sucking the fuel gas into the engine via a canister). When the jet fuel X in the compartment 16 reaches a height at which it starts to flow out as shown in FIG. The jet fuel X accumulated in the chamber 16 (fuel reservoir 17) rapidly flows into the sub tank 4, and the jet fuel
As shown in FIG. 6, the pressure in the upper part of the compartment 16 is reduced. At this time, since the pressure in the upper part of the sub-tank 4 is high in most cases, the first check valve 25 is pushed open as shown in FIG. 2 to allow the fuel gas to flow into the compartment 16. The room 1
The fuel X accumulated in the compartment 16 is lower than the inner opening 19 of the siphon device 18 as shown in FIG. If the pressure is higher than the fuel gas pressure in the fuel tank 1, the second check valve 30 is opened and the fuel tank 1 is removed.
Excrete inside.

When the jet fuel is return fuel from the return tube 8 and contains fuel gas, this gas accumulates in the upper layer of the compartment 16 and flows out into the tank 1 through the check valve 30 or through the siphon device 18.
The fuel is separated while flowing into the subtank 4 and is discharged into the subtank 4.

As shown in the second embodiment of FIG. 7, a branch pipe 31 branched outside the fuel tank 1 from the fuel supply pipe 7 of the fuel pump 6 is inserted from above the compartment 16 as the fuel jet tube of the present invention. can do.

(Function) The function of the present invention is that the sub-tank 4 is configured to have a negative pressure inside the sub-tank 4, and the fuel pump 6 supplies the fuel in the sub-tank 4 to the engine, thereby making the sub-tank 4 a negative pressure. 1
In addition, there is no function to make the inside of the sub-tank 4 negative pressure, and the sub-tank 4 is not refilled with fuel. Since a check valve 14 is provided in the replenishment tube 5 for new cars, etc., when the fuel tank 1 is filled with fuel, the sub-tank 4 is automatically refilled with fuel, and a nearly constant amount of jet fuel is As the gas accumulates, the gas is intermittently discharged into the sub-tank 4, and thereby the gas pressure inside the compartment 16 is periodically generated in two strong and weak states, and the gas pressure between the upper layer of the sub-tank 4 and the compartment 16 is The first check valve 25 provided in the sub-tank 4
The fuel gas that collects in the upper layer is discharged into the fuel tank 1 through the compartment 16 to raise the fuel level in the sub-tank 4, so that the sub-tank 4 is always full of fuel.

(Effects) The fuel pump unit of the present invention uses a new material for the sub-tank that enables negative pressure in the inner space, and with the configuration of the specific invention, it can be used as a countermeasure for new cars to reduce the negative pressure in the sub-tank generated by the fuel pump. This has the effect of easily producing the combined effect of refueling from the base fuel tank and discharging the fuel gas that collects in the upper layer of the sub-tank into the fuel tank. In addition, the second invention uses a jet tube as a return tube, and the third invention uses a branch tube provided on the discharge side of a fuel pump to discharge a part of the fuel. It has the effect that it can. Further, the fourth invention uses a siphon device as a device for storing a substantially constant amount of jet fuel and intermittently flowing it out into a sub-tank, and this siphon device has the effect of further improving reliability.

[Brief explanation of the drawing]

1 to 6 show a first embodiment of the present invention.
The figure is a longitudinal front view, Figure 2 is a longitudinal front view of the same main part,
FIG. 3 is a perspective view of the check valve 14, and FIGS. 4 to 6 are longitudinal sectional front views of the main parts, which explain the order in which the fuel gas in the upper layer of the sub-tank 4 is discharged into the fuel tank 1. 7th
The figure shows the second branch pipe 31 installed in the fuel pump.
It is the same longitudinal sectional front view as the figure. 1 → fuel tank, 3 → sealing lid, 4 → sub tank, 5 → supply tube, 6 → fuel pump, 8 → return tube, 14 → check valve, 16 → compartment,
17 → fuel reservoir, 18 → siphon device, 25 →
First check valve, 30→second check valve, 31→branch tube.

Claims (1)

[Scope of Claims] 1. A sub-tank whose internal air can be under negative pressure is provided in the fuel tank, and the end of the sub-tank faces the bottom of the fuel tank, and the fuel in the fuel tank is located near the bottom of the sub-tank. A replenishment tube equipped with a check valve that can be opened by pressure and a fuel pump connected to the engine are installed, a compartment is provided in the subtank, a fuel jet tube is inserted from above into the compartment, and the fuel jet tube is inserted into the compartment from above. is a fuel reservoir with a device that stores a nearly constant amount of jet fuel and intermittently flows out to the sub-tank, and the fuel gas pressure on the sub-tank side is adjusted to a position exceeding the height at which the intermittent flow of jet fuel starts in the compartment. A first check valve that is pushed by the fuel gas pressure in the farm room to open the valve on the side of the farm room and discharge gas, and a second check valve that is pushed by the fuel gas pressure in the farm room and opens the valve on the fuel tank side and discharges the gas. A fuel pump unit characterized in that it is provided with a check valve and that a negative pressure is created in a sub-tank by supplying fuel to an engine using a fuel pump, thereby causing fuel replenishment from a fuel tank using a replenishment tube. 2. The fuel pump unit according to claim 1, wherein the fuel jet tube is a return tube. 3. The fuel pump unit according to claim 1, wherein the fuel jet tube is a branch tube provided on the discharge side of the fuel pump and discharges part of the fuel. 4. A device that stores a nearly constant amount of jet fuel in a farm room and intermittently flows out to the sub-tank, the fuel that has accumulated in the farm room to the height of the outflow begins to flow to the sub-tank side, and A fuel pump unit according to claim 1, characterized in that the inner opening is a siphon device located near the bottom of the chamber.