JP2002364481A - Jet pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a jet pump in which a turning piece is not required, that is, the number of part items is reduced to implement efficient manufacturing thereof, and negative pressure is efficiently generated to stably transfer fuel even in a low flow rate area. SOLUTION: The jet pump 11 is attached to a returning pipe 7. A pump 4 pumps the fuel and supplies the fuel to an engine, and the returning pipe 7 returns the remaining fuel F into a fuel tank 1. The jet pump 11 sucks the fuel F in the fuel tank 1 to transfer the fuel F in a predetermined position in the fuel tank 1. A cutout part 12b for opening a side face outlet 12c is formed in a side face of a tip of a pump nozzle 12 having a fuel outlet 12a at the tip thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply system in which a fuel in a fuel tank is sucked up by a pump and supplied to an engine, and surplus fuel is returned to the fuel tank. The present invention relates to a jet pump for transferring to a predetermined position in a tank.

[0002]

2. Description of the Related Art In a fuel tank mounted on a vehicle such as an automobile, a bottom is depressed upward to separate the inside of the fuel tank into a main chamber and a sub chamber, or to accommodate a swirl tank. There is something. The former fuel tank needs to transfer the fuel in the sub chamber to the main chamber, and the latter fuel tank needs to transfer the fuel in the fuel tank to the swirl tank. As described above, the jet pump is used to transfer the fuel in the sub chamber to the main chamber or the fuel in the fuel tank to the swirl tank.

The above-mentioned jet pump is attached to a return pipe which sucks up the pump and supplies it to the engine and returns the surplus fuel to the fuel tank. The jet pump pumps out the surplus fuel from the pump nozzle at a high flow rate. By utilizing the negative pressure generated around the nozzle, the fuel in the sub chamber is transferred to the main chamber, or the fuel in the fuel tank is transferred to the swirl tank. The jet pump is provided with a turning piece in the pump nozzle in order to generate a turbulent flow so as to generate a negative pressure efficiently and perform stable fuel transfer (for example, Japanese Patent Publication No. 5-84).
No. 833).

[0004]

In the conventional jet pump, the flow of the fuel injected from the pump nozzle is widened so that a liquid seal can be easily formed so that a negative pressure can be efficiently generated and a stable fuel transfer can be performed. Since the turning piece must be mounted in the narrow jet pump nozzle, the work of mounting the turning piece is poor, and it has not been possible to manufacture efficiently. In addition, since a turning piece is required, the number of parts increases. In addition, turbulence cannot be reliably generated in a low fuel flow rate region, and stable fuel transfer cannot be performed.

The present invention has been made to solve the above-mentioned problems, and does not require a turning piece. That is, the present invention has a small number of parts, can be manufactured efficiently, and has a negative pressure. The present invention provides a jet pump capable of stably transferring fuel even in a low flow rate range of fuel by generating the pressure.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a recirculation pipe for sucking up a fuel by a pump and supplying the fuel to an engine and returning surplus fuel to a fuel tank. In a jet pump for transferring to a position, a cutout for opening a side outlet is provided on a side surface of a front end of a pump nozzle having a fuel outlet at a front end. And it is desirable to provide a wall portion below the pump nozzle that faces the flow of fuel ejected from the pump nozzle.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view showing an example of a fuel tank using a jet pump according to an embodiment of the present invention, FIG. 2 is a sectional view of the jet pump according to an embodiment of the present invention shown in FIG. 1, and FIG. It is a perspective view showing the tip part of a pump nozzle. Note that some of the relief nozzles in FIG. 2 are omitted.

[0008] In these figures, reference numeral 1 denotes a fuel tank, the inside of which is recessed upward to form a main chamber 2M.
And the sub chamber 2S. 4 indicates a pump,
The fuel F in the fuel tank 1 (main chamber 2M) is sucked up through a filter 5 and supplied to an engine (not shown) through a supply pipe 6 or the like. Reference numeral 7 denotes a return pipe, which is a pipe for returning surplus fuel F supplied to the engine by the pump 4 into the fuel tank 1 and connected to a jet pump 11 described later. Reference numeral 8 denotes a transfer pipe. One end (suction end) is disposed in the sub chamber 2S, and the other end (discharge end) is connected to the jet pump 11.

Reference numeral 11 denotes a jet pump, to which a reflux pipe 7 is connected, a fuel outlet 12a is provided at the tip (lower end), and a notch 12b is formed at the tip side to form a side outlet 12c communicating with the fuel outlet 12a. A pump nozzle 12 provided, a connection pipe portion 13 provided on a side surface of the pump nozzle 12 so as to communicate with the pump nozzle 12,
The pump nozzle 12 is provided in the connection pipe portion 13.
When the internal pressure rises above a predetermined pressure, the pump nozzle 12
Safety valve 14 for bypassing the fuel inside the pipe into the connection pipe section 13, a relief nozzle 15 connected to the connection pipe section 13, and a pump nozzle 1 below the connection pipe section 13
2 pump body part 1 which is continuously provided and whose peripheral edge is bent downward
6, a lid 17 which is attached to the lower end of the pump body 16 in a sealed state and forms a space S between the pump body 16 and the tip of the pump nozzle 12. Section 18 which contracts while maintaining a constant distance from
A connecting pipe 19 connected to the lid 17 and communicating with the space S, to which the other end of the transfer pipe 8 is connected;
And an L-shaped starter nozzle 20 connected to the starter nozzle. In addition, the part of the starter nozzle 20 facing the tip of the pump nozzle 12 and the tip of the throttle part 18 is formed by a wall part 20 a
Becomes

Reference numeral 31 denotes a mounting member, and the jet pump 1
1 is mounted in the fuel tank 1 and fixed.

Next, the supply and transfer of the fuel F will be described. First, when the pump 4 is driven, the fuel F in the main chamber 2M is discharged.
Is filtered by a filter 5, enters the pump 4, and is supplied to an engine (not shown) via a supply pipe 6 or the like. The surplus fuel F is supplied to the jet pump 11 via the return pipe 7 and the like.

When the surplus fuel F is supplied to the jet pump 11 in this manner, the surplus fuel F is ejected from both outlets 12a and 12c of the pump nozzle 12 at an increased flow rate, and is ejected by the throttle 18 to form a liquid seal. As a result, a negative pressure is generated around the pump nozzle 12. When the negative pressure is generated in this manner, the air in the space S is sucked, so that the fuel F in the sub-chamber 2S is sucked into the space S via the transfer pipe 8, and the jets from both outlets 12a and 12c are jetted. At the same time, they are mixed in the throttle unit 18 and supplied and transferred into the main chamber 2M.

When the pressure of the surplus fuel F supplied to the pump nozzle 12 becomes higher than the set pressure of the safety valve 14,
When the safety valve 14 opens, a part of the surplus fuel F in the pump nozzle 12 is supplied into the main chamber 2M via the relief nozzle 15.

As described above, when the surplus fuel F is ejected from both outlets 12a and 12c at an increased flow velocity, the fuel F injected due to the influence of the side outlet 12c tends to be turbulent.
It becomes easy to entrain the surrounding air. Further, since the fuel F is rebounded also on the wall portion 20a, the rebound amount of the fuel F is increased, so that the liquid seal is easily performed.

As described above, according to one embodiment of the present invention, by providing the pump nozzle 12 with the side outlet 12c in addition to the fuel outlet 12a, the fuel F injected under the influence of the side outlet 12c is low. Since the turbulent flow is easily generated and spread from the flow rate region, the liquid seal is easily formed on the inner surface of the throttle unit 18, the surrounding air is entrained to efficiently generate a negative pressure around the pump nozzle 12, and the fuel F Can be efficiently transferred. Therefore, unlike the conventional case, the turning piece is not required, that is, the number of parts is reduced, the jet pump 11 can be manufactured efficiently, and a negative pressure is efficiently generated to stably operate even in a low fuel flow rate region. Fuel transfer. Furthermore, by providing the wall portion 20a, the wall portion 20a is provided.
Since the fuel F that has become turbulent in step a is rebounded, the rebound amount of the fuel F becomes larger than the rebound amount in a laminar flow state, and liquid sealing is easily performed. In addition, the fuel F can be transferred even with the return amount of the fuel F, which cannot be transferred conventionally.

FIG. 4 is an explanatory view showing another example of a fuel tank using a jet pump according to an embodiment of the present invention. The same or corresponding parts as in FIGS. Is omitted.

In FIG. 4, the fuel tank 1 has a flat bottom and accommodates a swirl tank 3. And swirl tank 3
The fuel F inside is pumped up by the pump 4 and supplied to the engine,
The fuel F in the fuel tank 1 is transferred into the swirl tank 3. Reference numeral 21 denotes a guide pipe for guiding the fuel F from the starter nozzle 20 into the swirl tank 3.

As described above, when the swirl tank 3 is accommodated in the fuel tank 1, even if the vehicle leans and the fuel F runs out around the swirl tank 3 in a state where the fuel F is low, the fuel is introduced into the swirl tank 3. F can be transferred and supplied to the engine.

In the above-described embodiment, the example in which the fuel outlet 12a and the side outlet 12c are communicated has been described. However, even if the fuel outlet 12a and the side outlet 12c are not connected, the jet pump 11 will The fuel F can be transferred in the same manner as described.

[0020]

As described above, according to the present invention, by providing the pump nozzle with the fuel outlet and the side outlet, the fuel injected under the influence of the side outlet generates a turbulent flow from a low flow rate region. As it is easy to spread and easy to spread, it is easy to liquid seal on the inner surface of the throttle part, entrain the surrounding air and efficiently generate a negative pressure around the pump nozzle,
The fuel can be efficiently transferred. Therefore, there is no need for a turning piece as in the prior art, that is,
The number of parts is reduced, the jet pump can be manufactured efficiently, and the negative pressure can be efficiently generated to stably transfer the fuel even in a low fuel flow rate region. Further, by providing the wall portion, the turbulent fuel is rebounded at the wall portion, so that the rebound amount of the fuel is larger than the rebound amount in the laminar flow state, so that the liquid sealing is easily performed. Can be started at an early point in time, and the fuel can be transferred even with the return amount of fuel, which has not been possible in the past.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of a fuel tank using a jet pump according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the jet pump according to the embodiment of the present invention shown in FIG.

FIG. 3 is a perspective view showing a tip portion of a pump nozzle.

FIG. 4 is an explanatory view showing another example of a fuel tank using a jet pump according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel tank 2M Main chamber 2S Sub chamber 3 Swirling tank 4 Pump 5 Filter 6 Supply pipe 7 Reflux pipe 8 Transfer pipe 11 Jet pump 12 Pump nozzle 12a Fuel outlet 12b Notch 12c Side exit 13 Connection pipe 14 Safety valve 15 Relief nozzle 16 Pump body section 17 Lid section 18 Restricted section 19 Connection pipe section 20 Starter nozzle 20a Wall section 21 Guide pipe section 31 Mounting member F Fuel S Space

Claims (2)

[Claims] 1. A jet pump attached to a return pipe for pumping up and supplying surplus fuel supplied to an engine to a fuel tank and sucking the fuel in the fuel tank and transferring the fuel to a predetermined position in the fuel tank. 3. The jet pump according to claim 1, wherein a cutout for opening the side outlet is provided on a side surface of the front end of the pump nozzle having a fuel outlet at the end. 2. The jet pump according to claim 1, wherein a wall facing the flow of fuel ejected from the pump nozzle is provided below the pump nozzle.