JPH0511699Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a fuel tank device installed in, for example, an automobile and supplying fuel to an internal combustion engine, and in particular, the fuel tank is composed of a main tank and a sub tank. Related to fuel tank device.

[Conventional technology]

Conventionally, for example, fuel tank devices for automobiles include
It is known that the fuel tank is divided into a main tank that accommodates fuel as well as a fuel pump and the like, and a sub-tank that only accommodates fuel, due to constraints on the vehicle body structure or a desire to increase tank capacity.

3 and 4 show this type of fuel tank device according to the prior art.

In the figure, 1 is a fuel tank that accommodates fuel A, and the fuel tank 1 is provided with a bottom plate 2, a right side plate 3, a left side plate 4, a front plate (not shown), a rear plate 5, a fuel filler port 6A, and a pipe insertion port 6B. The fuel supply port 6A is covered by a cap 7, and the pipe insertion port 6B is normally closed by a cover plate 8. At the center of the bottom plate 2 of the fuel tank 1, a shaped part 2A for straddling the rear axle housing B is formed to protrude inside the fuel tank 1, and a right bottom plate part 2B and a left bottom plate part 2 of the shaped part 2A are formed.
By providing a step C, the fuel tank 1 is made up of an integrally formed deep-bottomed main tank 1A that accommodates a fuel pump 9, etc., which will be described later, and a shallow-bottomed sub-tank 1B.

Reference numeral 9 denotes a fuel pump that is located within the fuel tank 1 and is located on the side of the main tank 1A, and that pumps fuel A to a fuel injection valve 13, which will be described later.The fuel pump 9 has a pump part and a motor part in a casing. It is roughly composed of a pump body 9A, a filter 9C connected to the suction port 9B of the pump body 9A, and a discharge port 9D provided in the pump body 9A and equipped with a check valve for maintaining residual pressure inside. .

One end of 10 is the discharge port 9D of the fuel pump 9.
12 is a pressure regulator connected to the other end of the discharge pipe 10. The pressure regulator 12 is connected to a supply pipe 14 that supplies fuel to the fuel injection valves 13, 13, . . . and a control pressure pipe 16 that introduces positive or negative pressure generated in the intake manifold 15 as control pressure. By introducing the control pressure, out of the fuel flow rate supplied from the fuel pump 9, the return flow rate that is returned to the fuel tank 1 via the return piping 17, which will be described later, is controlled, and the fuel supplied to each fuel injection valve 13 is controlled. The pressure is controlled to a predetermined set pressure.

Reference numeral 17 denotes a return pipe for returning surplus oil of fuel A supplied from the fuel pump 9 to the fuel tank 1 side. One end side of the return pipe 17 is connected to the pressure regulator 12, and the other end side is connected to the fuel tank 1 side.
It extends to the main tank 1A side.

18 is an ejector located on the main tank 1A side and provided on the tip side of the return pipe 17 in order to suck the fuel A stored in the sub tank 1B of the fuel tank 1 and flow it into the main tank 1A side. The fuel suction pump 18 has a pump body 18A as shown in FIG.
An oil passage 18B that penetrates through the oil passage 18B and communicates with the return pipe 17, a large-diameter oil reservoir 18C that is provided in the middle of the oil passage 18B, and It consists of a passage 18B and a suction passage 18D communicating in a T-shape. The proximal end side of a suction pipe 19 is connected to the suction path 18D of the fuel suction pump 18, and the suction port on the distal end side 19A of the suction pipe 19 is connected to the suction path 18D of the fuel tank 1.
It is located below A and is arranged inside the sub tank 1B.

The conventional technology is configured as described above, and its operation will be explained next.

The fuel pump 9 is driven to supply fuel A in the fuel tank 1 to the fuel injection valve 13 side via the discharge pipe 10. At this time, the pressure regulator 12 introduces positive pressure or negative pressure from the intake manifold 15 as a control pressure, and controls the return flow rate of the fuel flow rate supplied from the fuel pump 9 to the fuel tank 1 side. The pressure of fuel supplied to the injection valve 13 is controlled to a predetermined set pressure.

Thus, the fuel injection valve 1 is activated by the fuel pump 9.
A part of the fuel A supplied to the fuel injection valve 1
3 into the combustion chamber of the internal combustion engine, and the remaining surplus oil is returned from the pressure regulator 12 to the fuel tank 1 via a return pipe 17.

Further, due to the negative pressure generated in the suction passage 18D due to surplus oil flowing through the oil passage 18B of the fuel suction pump 18 provided in the return piping 17, the fuel A in the sub-tank 1B is pumped through the suction pipe 19. Fuel A is sucked into the main tank 1A side, and fuel A from the sub tank 1B side is sequentially sent to the main tank 1A side as the fuel pump 9 is driven.

[Problem that the invention attempts to solve]

According to the prior art, while the fuel pump 9 is in operation, surplus oil is constantly returned to the fuel tank 1 via the pressure regulator 12, and therefore the fuel suction pump 18 is always sucked.
As a result, even when the remaining amount of fuel A in the sub-tank 1B becomes low and the suction port of the suction pipe 19 is exposed from the fuel A, the fuel suction pump 18 continues to suck the air inside the fuel tank 1. There is a problem in that a suction sound (sudden sound) is generated at this time and becomes a noise.

The present invention was developed in view of the above-mentioned drawbacks of the conventional technology, and is designed to prevent the generation of suction noise by automatically closing the suction port of the suction pipe when the fuel in the sub-tank reaches a predetermined level. The purpose of the present invention is to provide a fuel tank device that has the following features.

[Means for solving problems]

The feature of the means of the present invention, which is designed to solve the above-mentioned problems, is that a float valve is provided in the sub-tank, which constitutes the fuel tank together with the main tank, to close the suction port of the suction pipe when the fuel in the sub-tank decreases to a predetermined amount.

[Effect]

Fuel in the sub-tank of the fuel tank is sucked into the main tank through a suction pipe, and when the remaining amount of fuel in the sub-tank reaches a specified amount, a float valve automatically closes the suction port of the suction pipe, preventing the intake of air and reliably preventing the generation of suction noise.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 and 2. Note that the same components as those of the prior art described above are given the same reference numerals and will be referred to.

FIG. 1 shows a first embodiment of the present invention. In the figure, 21 is a suction pipe located on the bottom side of the fuel tank 1 and arranged from the main tank 1A to the sub-tank 1B.The suction pipe 21 is made of synthetic resin such as polyacetal, and its base end The side (not shown) is the fuel suction pump 1
It communicates with the suction passage 18D of No. 8. On the other hand, the tip side 21A of the suction pipe 21 extending into the sub-tank 1B
is bent upward and protrudes, and a suction port 21B with a slightly smaller diameter is formed at the tip.

Reference numeral 22 denotes a float valve that opens and closes the suction port 21B of the suction pipe 21 according to the increase or decrease of the fuel A in the sub-tank 1B. Suction port 2
1B, and a float 24 formed of synthetic resin into a hollow donut shape having a shaft insertion hole 24A in the center, and fixed to the upper surface of the valve body 23.

Reference numeral 25 denotes an opening formed in the upper plate 6 of the fuel tank 1 in order to arrange the float valve 22 in the fuel tank 1. The lid body 28 is tightened by
It is kept closed at all times. 29 is a shaft insertion hole 2 of the float valve 22 in order to guide the float valve 22, which moves up and down as the fuel A increases and decreases, only in the axial direction.
4A, the upper end of the guide rod 29 is inserted into and fixed to a thick plate-shaped fixing member 30 fixed to the lower surface of the lid 28, and the lower end is inserted through the suction port 21B. The suction tube 21 is arranged vertically so as to protrude into the suction pipe 21.

The present embodiment is constructed as described above, and the fuel pump 9 is driven to supply the fuel A in the fuel tank 1 to the fuel injection valve 13 side, and the pressure regulator 12 drains excess oil through the return pipe 17. and is returned into the fuel tank 1. Then, the excess oil is removed from the fuel suction pump 1 installed in the return pipe 17.
When flowing through the oil passage 18B of No. 8, the fuel from the sub tank 1B side is transferred to the main tank 1 through the suction pipe 21.
It is similar to the prior art in that it is attracted to the A side.

According to this embodiment, the fuel A rises and falls in the sub-tank 1B as the amount of fuel A increases and decreases, and when the fuel A decreases to just before the suction port 21B of the suction pipe 21 is exposed, the suction port 21B is closed. float valve 22
Since the suction pipe 21 is provided with
It is possible to reliably prevent the suction port 21B from being exposed from inside the fuel A and sucking in outside air, and generating suction noise at this time.

On the other hand, when the amount of fuel A in the fuel tank 1 increases by injecting the fuel A into the fuel tank 1 through the fuel filler port 6A, the float valve 22 is guided by the guide rod 29 and becomes buoyant. As it rises, the suction port 21B of the suction pipe 21 opens again, and the fuel A in the sub tank 1B is transferred to the main tank 1.
It can be supplied within A.

Next, FIG. 2 shows a second embodiment of the present invention.
In the figure, 31 is molded from synthetic resin such as polyacetal as in the first embodiment, and its base end (not shown) is a suction pipe that communicates with the suction passage 18D of the fuel suction pump 18. Suction tube 31
The distal end side 31A is located near the left side plate 4 in the sub-tank 1B and is bent upward, and a suction port 31B is formed at the distal end.

32 is a float valve that opens and closes the suction port 31B of the suction pipe 31, and the float valve 32 has a valve body 33 formed in the shape of a disk of foamed rubber or the like, and a hollow cylindrical shape whose inside is sealed. A synthetic resin float 34 fixed to the upper surface of the valve body 33, and a dogleg-shaped arm 35 that is integrally molded with the float 34 and projects laterally from the outer peripheral surface of the float 34.
and a shaft portion 36 formed to protrude from the distal end side 35A of the arm 35 in the orthogonal direction. 3
7 and 37 are a pair of support brackets (however, one is not shown) that are erected on the left bottom plate 2C in the sub-tank 1B to face each other across the suction pipe 31 in order to rotatably support the float valve 32. The shaft portion 36 is pivotally supported by the support bracket 37.

According to this embodiment configured as described above, the float valve 32 moves up and down around the shaft portion 36 as the fuel A in the sub-tank 1B increases and decreases, and when the fuel A decreases to a predetermined amount, the float valve 32 starts suctioning. This embodiment is the same as the first embodiment in that the suction port 31B of the pipe 31 is closed and the suction port 31B is opened when the fuel A increases, but the structure is simpler than the first embodiment. Therefore, the number of parts can be reduced.

Although the fuel tank 1 of each embodiment is composed of a main tank 1A and a sub-tank 1B formed integrally, there is also a fuel tank in which the main tank and the sub-tank are formed separately and arranged apart from each other. The present invention can also be applied to

[Effect of idea]

According to the present invention configured as detailed above,
The suction port of the suction pipe that leads the fuel in the sub-tank into the main tank is opened and closed by a float valve that moves up and down as the fuel in the sub-tank increases and decreases, so when the fuel decreases to a predetermined amount, the suction port opens and closes automatically. The suction port can be closed off, and the suction noise caused by sucking air from the suction port can be reliably prevented from being generated, thereby realizing a reduction in vehicle noise.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the main parts of a fuel tank device according to the first embodiment of the present invention, FIG. 2 is a cross-sectional view showing the main parts of the fuel tank device according to the second embodiment, and FIG. 4 is a system diagram showing the overall configuration of a fuel tank device according to the prior art, and FIG. 4 is an enlarged sectional view of the fuel suction nozzle shown in FIG. 3. 1...Fuel tank, 1A...Main tank, 1
B...Subtank, 9...Fuel pump, 17...
Return piping, 18...Fuel suction pump, 21,
31... Suction tube, 21B, 31B... Suction port, 2
2, 32...Closing valve.

Claims (1)

[Scope of utility model registration request] A fuel tank consisting of a main tank and a sub-tank, a fuel pump provided on the main tank side of the fuel tank and supplying fuel to the fuel injection valve side, and a pressure regulator that regulates the pressure of the fuel supplied by the fuel pump. a return piping connected to the tank for returning surplus oil to the fuel tank; and a fuel suction pump installed in the return piping for sucking fuel in the sub-tank into the main tank by utilizing the flow of the surplus oil. and a suction pipe whose base end is connected to the fuel suction pump and whose distal end side has a suction port opened into the sub-tank, wherein the fuel in the sub-tank is reduced to a predetermined amount. A fuel tank device characterized in that a float valve is provided that closes a suction port of the suction pipe when the suction pipe is closed.