JP4484399B2 - Jet pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
This invention is attached to a return pipe that sucks up fuel in a fuel tank with a pump and supplies it to the engine to return surplus fuel into the fuel tank. The fuel in the fuel tank is sucked and transferred to a predetermined position in the fuel tank. The present invention relates to a jet pump.
[0002]
[Prior art]
Some fuel tanks mounted on vehicles such as automobiles have a bottom that is recessed upward to separate the fuel tank into a main chamber and a sub chamber, or contain a swirl tank.
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 into the swirl tank.
In this way, a jet pump is used to transfer the fuel on the sub chamber side to the main chamber side or the fuel in the fuel tank to the swirl tank.
[0003]
The above-described jet pump is attached to a reflux pipe that is pumped up by the pump and supplied to the engine to return surplus fuel into the fuel tank. The surplus fuel from the pump nozzle is ejected at an increased flow rate to surround the pump nozzle. By using the negative pressure generated in the sub-chamber, the fuel on the sub chamber side is transferred to the main chamber side or the fuel in the fuel tank is transferred to the swirl tank.
In order to generate a turbulent flow so that the negative pressure can be efficiently generated and the fuel can be stably transferred, the jet pump has a turning piece installed in the pump nozzle (for example, Japanese Patent Publication No. 5-84833). ).
[0004]
[Problems to be solved by the invention]
The conventional jet pump generates a negative pressure efficiently and enables stable fuel transfer, so that the flow of fuel injected from the pump nozzle is widened to facilitate liquid sealing. Therefore, the workability of attaching the turning piece is poor, and it has not been possible to manufacture efficiently.
Moreover, since a turning piece is required, the number of parts increases.
In addition, turbulent flow could not be reliably generated in the low flow rate region of fuel, and stable fuel transfer could not be performed.
[0005]
The present invention has been made to solve the above-described problems, and does not require a turning piece, that is, it can be efficiently manufactured with a small number of parts, and can efficiently generate a negative pressure. Thus, it is an object of the present invention to provide a jet pump that can stably transfer fuel even in a low flow rate region of fuel.
[0006]
[Means for Solving the Problems]
The present invention relates to a jet pump that is attached to a return pipe that sucks up with a pump and supplies it to an engine to return surplus fuel into the fuel tank, and sucks the fuel in the fuel tank and transfers it to a predetermined position in the fuel tank. A notch is formed on only one side surface of the front end of the pump nozzle having a fuel outlet, and a side surface outlet communicating with the fuel outlet is opened . And it is desirable to provide the wall part which opposes the flow of the fuel which a pump nozzle ejects under a pump nozzle.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
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 which shows the front-end | tip part of a pump nozzle.
Note that a part of the relief nozzle in FIG. 2 is omitted.
[0008]
In these drawings, reference numeral 1 denotes a fuel tank, and the inside is separated into a main chamber 2M and a sub chamber 2S by denting the bottom upward.
Reference numeral 4 denotes a pump, which sucks up fuel F in the fuel tank 1 (main chamber 2M) through a filter 5 and supplies it to an engine (not shown) through a supply pipe 6 and the like.
Reference numeral 7 denotes a recirculation pipe, which is a pipe for returning surplus fuel F supplied to the engine by the pump 4 into the fuel tank 1, and is 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.
[0009]
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 side outlet 12c that is communicated with the fuel outlet 12a by forming a notch 12b at the tip side surface. The nozzle 12, the connection pipe portion 13 provided on the side surface of the pump nozzle 12 so as to communicate with the pump nozzle 12, and the connection pipe portion 13 provided in the connection pipe portion 13 so that the pressure in the pump nozzle 12 increases to a predetermined pressure or more. Then, the safety valve 14 that bypasses the fuel in the pump nozzle 12 into the connection pipe portion 13, the relief nozzle 15 connected to the connection pipe portion 13, and the pump nozzle 12 below the connection pipe portion 13 are connected in series. The pump body part 16 whose peripheral edge is bent downward, and the lower end of the pump body part 16 are attached in a sealed state, and the pump body part 1 A lid portion 17 that forms a space S therebetween, a constricted portion 18 that is contiguous to the lid portion 17 and keeps a constant distance from the tip of the pump nozzle 12, and a lid portion 17. The connection pipe portion 19 communicates with the space S and is connected to the other end of the transfer pipe 8 and the L-shaped starter nozzle 20 connected to the throttle portion 18.
Note that a portion of the starter nozzle 20 facing the tip of the pump nozzle 12 and the tip of the throttle portion 18 becomes a wall portion 20a facing the flow of the fuel F ejected by the pump nozzle 12.
[0010]
Reference numeral 31 denotes an attachment member for attaching and fixing the jet pump 11 in the fuel tank 1.
[0011]
Next, supply and transfer of fuel F will be described.
First, when the pump 4 is driven, the fuel F in the main chamber 2M is filtered by the filter 5, enters the pump 4, and is supplied to the engine (not shown) via the supply pipe 6 and the like.
The surplus fuel F is supplied to the jet pump 11 through the reflux pipe 7 and the like.
[0012]
When surplus fuel F is supplied to the jet pump 11 in this way, the surplus fuel F is ejected from the outlets 12a and 12c of the pump nozzle 12 at an increased flow velocity, and is liquid-sealed at the throttle 18. A negative pressure is generated around the pump nozzle 12.
When negative pressure is generated in this manner, the air in the space S is sucked, whereby the fuel F in the sub chamber 2S is sucked into the space S through the transfer pipe 8, and jets from both outlets 12a and 12c. At the same time, it is mixed in the throttle unit 18 and supplied and transferred into the main chamber 2M.
[0013]
When the pressure of the surplus fuel F supplied to the pump nozzle 12 becomes equal to or higher than the set pressure of the safety valve 14, the safety valve 14 is opened, so that a part of the surplus fuel F in the pump nozzle 12 is relieved. Is supplied into the main room 2M.
[0014]
As described above, when the excess fuel F is ejected from both the outlets 12a and 12c with the increased flow velocity, the fuel F injected due to the influence of the side outlet 12c is likely to be turbulent and easily entrain surrounding air. .
Furthermore, since the fuel F is bounced back even in the wall portion 20a, the amount of bounce of the fuel F increases so that liquid sealing is facilitated.
[0015]
As described above, according to the embodiment of the present invention, by providing the pump nozzle 12 with the side surface outlet 12c in addition to the fuel outlet 12a, the fuel F injected under the influence of the side surface outlet 12c is reduced from the low flow rate region. Since turbulent flow is easily generated and spreads easily, it is easy to liquid-seal the inner surface of the throttle portion 18, entraining the surrounding air, efficiently generating negative pressure around the pump nozzle 12, and transferring the fuel F This can be done efficiently.
Therefore, a turning piece is not required as in the prior art, that is, the number of parts is reduced, the jet pump 11 can be efficiently manufactured, and negative pressure is efficiently generated and stable even in a low flow rate region of fuel. The transferred fuel can be transferred.
Furthermore, by providing the wall portion 20a, the fuel F turbulent in the wall portion 20a is rebounded, so that the amount of rebound of the fuel F is larger than the amount of rebound in the laminar flow state, so that liquid sealing is facilitated. The start of the transfer of the fuel F can be started at an early point, and the fuel F can be transferred even with the return amount of the fuel F, which has conventionally been impossible to transfer the fuel F.
[0016]
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. .
[0017]
In FIG. 4, the fuel tank 1 has a flat bottom and accommodates the swirl tank 3.
The fuel F in the swirl tank 3 is sucked up by the pump 4 and supplied to the engine, and the fuel F in the fuel tank 1 is transferred into the swirl tank 3.
Reference numeral 21 denotes a guide pipe portion that guides the fuel F from the starter nozzle 20 into the swirl tank 3.
[0018]
As described above, when the swirl tank 3 is housed in the fuel tank 1, the fuel F is transferred into the swirl tank 3 even when the vehicle is tilted and the fuel F runs out around the swirl tank 3 with the fuel F being reduced. Can be supplied to the engine.
[0019]
In the above-described embodiment, an example in which the fuel outlet 12a and the side surface outlet 12c are communicated is shown. However, even if the fuel outlet 12a and the side surface outlet 12c are not in communication, the jet pump 11 is the same as described above. The fuel F can be transferred to the tank.
[0020]
【The invention's effect】
As described above, according to the present invention, in addition to the fuel outlet of the pump nozzle, a notch is formed only on one side surface of the tip, and the side surface outlet communicating with the fuel outlet is opened. The fuel injected in the air easily generates turbulent flow from the low flow rate region and spreads easily, so that it is easy to liquid-seal on the inner surface of the throttle, and the surrounding air is entrained and negative pressure is efficiently applied around the pump nozzle. The fuel can be transferred efficiently. Therefore, it does not require a turning piece as in the conventional case, that is, the number of parts is reduced, the jet pump can be manufactured efficiently, and the negative pressure is generated efficiently and stable even in a low flow rate region of fuel. Fuel can be transferred. Furthermore, by providing the wall, the fuel turbulent in the wall is rebounded, so that the amount of fuel rebounding is greater than the amount of rebounding in the laminar flow state, making it easier to liquid-seal. Can be started at an early point, and the fuel can be transferred even with the return amount of the fuel that could not be transferred conventionally.
[Brief description of 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.
2 is a cross-sectional view of the jet pump according to one 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 an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fuel tank 2M Main chamber 2S Sub chamber 3 Swivel tank 4 Pump 5 Filter 6 Supply pipe 7 Recirculation pipe 8 Transfer pipe 11 Jet pump 12 Pump nozzle 12a Fuel outlet 12b Notch part 12c Side outlet 13 Connection pipe part 14 Safety valve 15 Relief nozzle 16 Pump body part 17 Lid part 18 Restriction part 19 Connection pipe part 20 Starter nozzle 20a Wall part 21 Guide pipe part 31 Mounting member F Fuel S Space

Claims (2)

In a jet pump that is attached to a return pipe that sucks up with a pump and supplies it to the engine to return surplus fuel into the fuel tank, and sucks the fuel in the fuel tank and transfers it to a predetermined position in the fuel tank.
A jet pump characterized in that a cutout portion is formed only on one side of the tip of a pump nozzle having a fuel outlet at the tip, and a side outlet communicating with the fuel outlet is opened .   2. The jet pump according to claim 1, wherein a wall portion facing a flow of fuel ejected from the pump nozzle is provided below the pump nozzle. 3.

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