JPH0678760B2 - Fuel tank fuel suction device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fuel suction device for a fuel tank mounted on a vehicle such as an automobile.

2. Description of the Related Art Among fuel tanks for automobiles, for example
As disclosed in Japanese Patent Publication No. 21, a bulging portion is formed inward on the bottom wall of the tank body due to the structural reason of the portion where the fuel tank is mounted, and the bulging portion causes the bulging portion of the tank body to move. It is known to avoid interference between the bottom wall and the functional parts of the vehicle body.

Problems to be Solved by the Invention By forming a bulging portion on the bottom wall of the tank main body, the main chamber and the sub chamber are separated from each other in the substantially lower half of the tank main body. The feed pipe is branched from the middle into the main chamber side pipe and the sub chamber side pipe so that the fuel does not remain in either side, and the switching valve is activated when the fuel in the main chamber is consumed. Then, the fuel in the sub chamber must be supplied. Therefore, not only a switching valve is required, but also a liquid level detecting device is required for each of the main chamber and the sub chamber in order to automatically switch the switching valve, and a control unit is required. It has been pointed out that there is a problem that it becomes expensive.

Therefore, the present invention provides a fuel suction device for a fuel tank that can efficiently supply the fuel in the main chamber and the sub chamber without requiring dedicated parts such as the switching valve and its operation control unit. .

Means for Solving the Problems A return pipe and a suction pipe are provided, a nozzle is formed at the end of the return pipe, and a chamber that includes the nozzle and communicates with the suction pipe is formed. A fuel suction device for a fuel tank including an ejector pump in which a throttle portion and a throat portion following the throttle portion are formed below the nozzle, and a diffusion device having a pair of blades for diffusing and ejecting fuel to the nozzle is provided. Installed internally, set the crossing angle of the blades in the range of 60 ° to 120 °, and set the ratio of the nozzle inner diameter to the throat inner diameter to 0.4 to
It is set in the range of 0.8.

The fuel discharged from the return pipe is vigorously ejected from the nozzle, and a negative pressure is generated around the nozzle of the chamber due to the ejection of the fuel, and the fuel from the suction pipe is sucked into the chamber and is also ejected from the nozzle. The flow velocity is increased by the constriction part together with the jet flow of and is discharged from the throat part.

Here, by the diffusion device provided in the nozzle, the fuel ejected from the nozzle is injected in a cone shape on the inner wall of the throttle portion or the like below the nozzle while being diffused, and the suction of air from the throat portion following the throttle portion. Prevent.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

In FIGS. 1 and 2, reference numeral 1 denotes a tank main body, and a bulging portion 2 is formed inwardly at a substantially central portion of a bottom portion thereof,
A main chamber 3 and a sub chamber 4 are separated from each other in a substantially lower half portion of the tank body 1. A feed pump P is attached to the lower end of the feed pipe 5 in the main chamber 3, and a filter 6 is disposed at the suction port of the feed pump P, for example. The fuel is filtered by the filter 6 and fed to the fuel supply device described later via the feed pipe 5. Reference numeral 7 denotes a return pipe projectingly arranged in the tank body 1 for returning excess fuel not consumed by the fuel supply device into the tank body 1, and a chamber 9 is provided at an end of the return pipe 7.
Has been formed. A nozzle 8 projecting into the chamber 9 is formed at the end of the return pipe 7, and a narrowed portion 10 and a throat portion 11 are formed below the nozzle 8 of the chamber 9. The throat section 11 is arranged in the main chamber 3.

Here, inside the nozzle 8, there is provided a swirling piece 100 as a diffusing device for swirling and diffusing the fuel ejected from the tip of the nozzle 8.

As shown in FIGS. 4 to 8, the turning piece 100 extends from the base piece portion 100a and the base piece portion 100a, and the wing portions as a pair of blades wrap around while twisting to each other. Ten
0b, and by arranging the base piece portion 100a on the upstream side, the fuel is distributed to the front and back sides of each blade portion 100b to swirl the fuel.

Reference numeral 12 denotes a communication pipe as a suction pipe arranged near the bottom of the sub chamber 4 of the filter 12a having an opening at one end, and the communication pipe 12 is connected to the peripheral side of the nozzle 8 of the chamber 9 for communication. An ejector pump 13 is formed at a connection portion between the communication pipe 9 and the communication pipe 12.

In this embodiment, the ejector pump 13 is an ejector body 13a in which the chamber 9, the throttle portion 10 and the throat portion 11 are integrated, the nozzle 8 and the port 7a of the return pipe 7.
And a lid 13b in which the communication pipe 12 and the port 12b of the communication pipe 12 are unitized.
It consists of and.

Here, the pair of blade portions 100b of the turning piece 100 have an intersection angle θ set to 60 ° to 120 °.
The cone-shaped jet flow given by 00b is jetted to the narrowed portion 10 with an optimal spread.

That is, if the crossing angle is too large, the jet flow spreads too much and collides with the throttle portion 10, causing a loss in the jet flow, and the substantial amount of the jet flow causing the ejector action decreases. If the corner is too small, the throat part
This is because a gap is created between 11 and the jet flow, and outside air is introduced from this portion into the chamber 9 in a negative pressure state, and the negative pressure effect is canceled out, and the ejector action cannot be sufficiently exerted.

Further, in this embodiment, the dimensions of the ejector pump 13 are set as follows.

Do / Dt = 1, Do / l = 0.5, Dn / L = 4, Dn / Dt = 0.2 to 1, SL = 2Dt to 8Dt l: Distance from center of turning piece 100 to nozzle 8 tip L: Nozzle 8 Distance from tip to inlet of throat section 11 Dn: Inner diameter of nozzle Dt: Inner diameter of throat section Do: Inner diameter of port 7a where swivel piece 100 is installed SL: Length of throat section 11 Dn / Dt = The setting of 0.4 to 1, SL = 2Dt to 8Dt is because it is a range in which the ejector action can be effectively exhibited.

Next, FIG. 3 shows experimental results for determining the crossing angle of the turning piece 100. The horizontal axis represents the crossing angle θ and the vertical axis represents the suction pressure P.
Show as.

In this experiment, Dn / Dt is mainly focused on the case of Dn / Dt = 0.5.
= 0.4, 0.8, the following results were obtained using a turning piece capable of changing the crossing angle θ.

Dn / Dt = 0.5, flow rate 20 / h (shown by broken line) Dn / Dt = 0.5, flow rate 150 / h (shown by solid line) Dn / Dt = 0.4, flow rate 150 / h (shown by dashed line) Dn / Dt = 0.8, flow rate 150 / h (shown by the chain double-dashed line) From the above experimental results, it is ensured that the required pressure at which the fuel can be sucked from the sub chamber 4, that is, the reference pressure of −0.06 (kg / cm ² ) The turning angle of the turning piece is 60 °
It was in the range of 120 °.

In the above experiment, the suction height H of the communication pipe 12
Was 300 mm, the inner diameter of the communication pipe 12 was 6 mm, and the suction pressure -0.06 kg / cm ² actually required was set.

Further, the reason why the experiments were carried out for the flow rates of 20 / h and 150 / h is to consider the return flow rate of 100 / h when the vehicle is idling and the return flow rate of 25 to 80 / h when the vehicle is running.

Further, if Dn / Dt is made larger than 0.5, the peak of the suction pressure P becomes lower than the peak of the suction pressure P when Dn / Dt = 0.5, and the crossing angle θ at which the peak appears becomes smaller and the crossing angle θ and the suction pressure P It is confirmed that the characteristic curve of P draws a gentle convex curve, but conversely, if Dn / Dt is made smaller than 0.5, the peak of the suction pressure P decreases and the characteristic curve draws a steep convex curve. Therefore, when Dn / Dt is in the range of 0.4 to 0.8, suction pressure P
However, if the crossing angle θ is in the range of 60 ° to 120 °, it is possible to secure a suction pressure of -0.06 (kg / cm ² ) or more, which can sufficiently exert the ejector action.

From the above experimental results, the optimum angle range of the crossing angle θ of the turning piece 100 was clarified.

According to the above-described structure of the embodiment, when the feed pump P is driven, the fuel in the main chamber 3 is filtered by the filter 6 as shown in FIG.
The fuel is supplied from the feed pipe 5 after being filtered by
Sent to.

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

Here, since the end of the return pipe 7 is formed as the nozzle 8 in the chamber 9 forming the ejector pump 13, the fuel is discharged from the nozzle 8 by the discharge pressure of the feed pump P.
It is jetted vigorously toward the narrowed portion 10 and the throat portion 11. Therefore, a negative pressure is generated around the nozzle 8 in the chamber 9, and the negative pressure causes the fuel in the sub chamber 4 to be sucked into the chamber 9 through the communication pipe 12, and the nozzle 8
Along with the jet flow from the throat, the flow velocity is increased by the throttle unit 10 and is fed from the throat unit 11 into the main chamber 3, where an ejector action occurs, and the fuel in the sub-chamber 4 returns to the tank body 1 of the surplus fuel. Transferred into the main room 3.

Here, since the fuel injected from the nozzle 8 is swirling in the nozzle 8 by the swirling piece 100 as shown in FIG. 5, it diffuses from the tip of the nozzle 8 into a cone shape as shown in FIG. Therefore, the throat portion 11 side of the chamber 9 is closed by this cone-shaped jet flow. As a result, the negative pressure generated in the chamber 9 is not lost,
It acts on the communication pipe 12 side, and therefore the fuel suction force is substantially increased and the fuel suction time from the sub chamber 4 is shortened as compared with the case where fuel is injected in a spot shape from the nozzle 8. You can

Especially, the crossing angle of the wing 100b of the turning piece 100 is 60 ° to 1
Set it in the range of 20 ° and set the throat part 11 of the ejector pump 13
Since the ratio of the inner diameter Dn of the nozzle 8 to the inner diameter Dt is set in the range of 0.4 to 0.8, the ejector action can be sufficiently exerted even when the return flow rate is small.

Incidentally, the embodiment of the present invention is not limited to the above, for example, the turning piece, if the crossing angle of the turning blade is within the set range, as shown in FIG. The tip may be flat. Further, various structures can be adopted for the ejector pump as long as the dimensions can be set as described above.

Further, although the return pipe is used in the above embodiment, a pipe communicating with the feed pump may be used to return a part of the fuel into the tank body.

EFFECTS OF THE INVENTION As described above, according to the present invention, the nozzle that projects into the chamber of the ejector pump is provided with the diffusion device,
Because the crossing angle of the diffuser blade is set in the range of 60 ° to 120 °, and the ratio of the inner diameter of the nozzle to the inner diameter of the throat is set in the range of 0.4 to 0.8, traveling with a small return flow rate Even at this time, the fuel ejected from the nozzle diffuses to block the lower side of the chamber below the nozzle to prevent the intake of air from the tapered opening, and a sufficient intake pressure can be obtained.

Therefore, the negative pressure generated in the chamber can be exerted on the suction pipe without loss and the ejector action can be efficiently exhibited.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIG. 1 is an overall sectional view, FIG. 2 is an enlarged sectional view of an essential part of FIG. 1, FIG. 3 is a graph view, and FIG. 4 is a perspective view of a turning piece. 5 to 8 are a front view, a plan view, a side view and a rear view of the turning piece, respectively.
FIG. 10 is a fuel supply system diagram, and FIGS. 10 and 11 are a perspective view and a front view showing another embodiment of the turning piece. 7 ... Return pipe, 8 ... Nozzle, 9 ... Chamber, 10 ... Throttle part, 11 ... Throat part, 12 ... Communication pipe (suction pipe), 13 ... Ejector pump, 100 ... Rotating piece (Diffuser), 100b …… Wing (wing), θ ……
Crossing angle, Dt …… Inner diameter of throat, Dn …… Inner diameter of nozzle.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location F02M 37/18 7049-3G (72) Inventor Junya Ohno 2 Takara-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Automobile Co., Ltd. (72) Inventor Katsunori Ozaki 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Inventor Kiyokazu Yamamoto 1760, Higashimatano-cho, Totsuka-ku, Yokohama, Kanagawa Pref. ) Inventor Toshiyuki Matsuki 1760 Higashimatano-cho, Totsuka-ku, Yokohama-shi, Kanagawa Automotive Electric Industry Co., Ltd. (56) References Japanese Patent Publication No. 31-6039 (JP, B1)

Claims (1)

[Claims] 1. A return pipe and a suction pipe are provided,
A nozzle is formed at the end of the return pipe, and a chamber that includes the nozzle and communicates with the suction pipe is formed. A throttle portion is provided below the nozzle of the chamber.
In a fuel suction device for a fuel tank including an ejector pump in which a throat portion following a throttle portion is formed, a crossing angle of the blades is provided by incorporating a diffusion device having a pair of blades for diffusing and ejecting fuel into the nozzle. Is set in the range of 60 ° to 120 °, and the ratio of the inner diameter of the nozzle to the inner diameter of the throat part is set in the range of 0.4 to 0.8.