JPS63192615A - Fuel suction device for fuel tank - Google Patents

Abstract

PURPOSE:To provide a fuel suction device for a car fuel tank, wherein supply efficiency of the fuel in a main and an aux. chamber is enhanced, by internally fitting a fuel diffusing device within a nozzle formed at the end of an induction pipe, forming this diffusing device from a pair of vanes intersecting with a certain specific angle,and thereby eliminating specially devoted parts. CONSTITUTION:The surplus portion of the fuel sent to a fuel supply device by a feed pump is allowed to jet to a throttle 10 and a throat 11 from a return pipe 7 and an ejector pump 8. This generates negative pressure in a chamber 9 around the nozzle 8 to allow suction of the fuel in an aux. chamber via a communication pipe 12 and also sending thereof to a main chamber together with jet stream from the nozzle 8. In the nozzle 8, at this time, a piece for revolution 100 revolves which has a vane intersecting angle theta of 140 deg. or less, and the jet stream from the nozzle 8 is diffused conically, followed by shutting of the throat 11, that suppresses neg. pressure loss in the chamber 9. This enhances the suction efficiency to lead to accomplishment of an enhanced supply efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION This invention relates to a fuel suction device for a fuel tank mounted on a vehicle such as an automobile.

Conventional technologyIn the fuel tank for automobiles, for example,
As shown in Publication No. 09921, due to the structure of the part where the fuel tank is mounted, an inward bulge is formed on the bottom wall of the tank body, and this bulge allows the tank body to It is known to avoid interference between the bottom wall and functional parts of the vehicle body.

Problems to be Solved by the Invention By forming a bulge on the bottom wall of the tank body, the main chamber and the sub-chamber are separated approximately in the lower half of the tank body. To prevent fuel from remaining in one side, the feed pipe is branched into the main chamber side pipe and the auxiliary chamber side pipe through a switching valve, and the switching valve is activated so that the fuel in the main chamber is consumed. It is necessary to ensure that the fuel in the pre-chamber is supplied. For this reason, not only is a switching valve required, but in order to automatically switch and operate this switching valve, a liquid level detection device is required in each of the main chamber and auxiliary chamber, and a control unit is also required. It has been pointed out that there are problems with the product that make it expensive.

Therefore, the present invention does not require dedicated parts such as a switching valve or its operation control unit, and provides a fuel tank that can efficiently supply fuel in the main chamber and sub-chamber.
This is Shino, which provides a water suction device.

Means for Solving the Problems A guide pipe and a suction pipe are provided, and if a nozzle is formed at the end of the guide pipe, a chamber containing the nozzle and communicating with the suction pipe is formed; In a fuel suction device for a fuel tank, which includes an ejector pump in which a constriction part and a throat part following the constriction part are formed below the nozzle, fuel is diffused into the nozzle.
It is equipped with a diffuser equipped with a pair of wings that ejects water.''
The crossing angle of the blades is set to 140° or less.

The fuel led out from the action induction pipe is vigorously jetted out from the nozzle, and this jetting of fuel creates a negative pressure around the nozzle of the chamber, and when the fuel from the suction pipe is sucked into the chamber. Then, together with the jet from the nozzle, the flow velocity is increased by the constriction part and the fluid is discharged from the throat part.

Here, due to the diffusion device provided in the nozzle, the fuel ejected from the nozzle is diffused and injected in a cone shape onto the inner wall of the constriction section below the nozzle, and air is sucked in from the throat section following the constriction section. to prevent

Example Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In Fig. 1.2, reference numeral 1 designates a tank body, and a bulge 2 is formed inward at approximately the center of the bottom of the tank body. 3 and an auxiliary chamber 4 are separated from each other. A feed pump P is attached to the lower end of the feed pipe 5 in the main chamber 3, and a filter 6, for example, is disposed at the suction port of the feed pump P. The fuel is filtered by a filter 6 and then sent to a fuel supply device, which will be described later, via a feed pipe 5. Reference numeral 7 denotes a return pipe that is arranged protrudingly within the tank body 1 and serves as a guide pipe for returning surplus fuel that is not consumed by the fuel supply device into the tank body.A chamber 9 is provided at the end of the return pipe 7. It is formed. A nozzle 8 protruding into the chamber 9 is formed at the end of the return pipe 7, and a constricted part 10 and a throat part 11 are formed in the lower blade of the nozzle 8 of the chamber 9. This throat portion 11 is arranged inside the main chamber 3.

Here, a swirling piece 100 is provided inside the nozzle 8 as a diffusion device that swirls and diffuses the fuel ejected from the tip of the nozzle 8.

This turning piece 100, as shown in FIGS. 4 to 8,
The base piece 100a is composed of a base piece 100a and a pair of wings 100b extending from the base piece 100a and twisting around the other base.
By arranging wing a on the upstream side, the fuel can be swirled by distributing it to the front and back sides of each wing portion 100b.

Reference numeral 12 denotes a communication pipe as a suction pipe in which a filter 12a with one end open Lj is disposed near the bottom of the auxiliary chamber 4. This communication pipe 12 is connected to the circumferential side of the nozzle 8 of the chamber 9, and An ejector pump 13 is configured at a connecting portion between the chamber 9 and the communication pipe 12.

In this embodiment, the ejector pump 13 is composed of an ejector body 13a that integrates the chamber 9, the throttle part IO, and the throw 1-31<11, a boat 7a of the nozzle 8 and the litter pipe 7, and a boat 12b of the communication vibe 12. It is composed of a 2:i body 13b which is made into a unit.

Here, a pair of wing parts 100b of the turning piece I00
The intersecting angle θ is set to 426 to 135°, so that the cone-shaped jet provided by the blade portion 1oob is ejected to the constriction portion 10 with an optimal spread.

That is, if the above-mentioned crossing angle is too large, the jet flow will spread out too much, collide with the above-mentioned constriction part IO, and the substantial amount of the jet flow that will cause a loss there and cause an ejector action will be reduced. On the other hand, if the crossing angle is too small, a gap will be created between the throat part 11 and the jet stream, and outside air will be introduced from this part into the chamber 9 which is in a negative pressure state, canceling out the negative pressure effect and ensuring sufficient ejector action. This is because they will not be able to demonstrate their full potential.

Further, in this embodiment, the dimensions are set to be less than or equal to the dimensions of the ejector pump 13.

Do/Dt=I, Do/&=0.5゜D n / L = 4, I) n / D t
= 0, 2~! .

5L=2Dt~8Dt Q, Distance L from the center of the turning piece 100 to the tip of the nozzle 8; Distance from the tip of the nozzle 8 to the person L of the throat section 11 Dn: Inner diameter of the nozzle Dt Inner diameter of the throat section Do = For turning The inner diameter SL of the boat 7a portion in which the piece 100 is installed, the length of the throat portion 11, Dn/D t =0.2~I, SL = "2D t
The reason for setting the value to 8Dt is that this is the range in which the ejector action can be effectively exerted.

Next, the experimental results for determining the crossing angle of the turning piece 100 are shown in FIG. 3, with the horizontal axis representing the crossing angle θ and the vertical axis representing the suction pressure P.
Shown as

In this experiment, we mainly focused on the case where Dn/Dt=0.5 and the case where Dn/Dt=0.4. Regarding o-s, the following results were obtained using a turning piece that can change the intersecting angle θ.

■Dn/Dt-0.5. Flow rate 2Of2/h C shown by broken line) ■Dn/Dt= 0.5. Flow m 150G! /h
(indicated by a solid line) ■Dn/Dt=0.4. flow m 15
0Q/h C shown by dashed line t)■Dn/Dt= 0.8
．． From the above experimental results (indicated by the two-dot chain line), the flow rate is 150 &/h (indicated by the two-dot chain line). The intersection angle θ of the turning piece is 42° to 13
It was between 5°.

In the above experiment, the suction height H of the communicating pipe 12 was set to 300 zx, the inner diameter of the communicating vibe 12 was set to 61 cm, and the actually required suction pressure was set to 0.06 cm".

Also, the flow rate is 21! /h, l 50Q/h The experiment was conducted using the return flow rate BtoO&/h when the vehicle is idling and the return flow rate 25~80 (
This is because 2/h was taken into consideration.

Furthermore, if D n / D t is made larger than 0.5, the peak of suction pressure P will be lower than the peak of suction pressure P when D n / D t = 0 or 5, and the peak will be smaller than the intersection angle of 0. Moreover, the characteristic curve of the crossing angle θ and the suction pressure P draws a gentle convex curve, but on the contrary, D n /
It is confirmed that if I) t is made smaller than 0.5, the peak of the suction pressure I) decreases and the characteristic curve draws a steep convex curve, so D n / D t is larger than 0.5. In this case, although the peak of the suction pressure P decreases, the ejector action can be sufficiently exerted even if the intersection angle 0 is 42 degrees or less.

From the above experimental results, the optimum angular range of the intersection angle θ of the turning piece 100 has been clarified.

According to the structure of the above embodiment, when the feed pump P is driven, the fuel in the main chamber 3 is transferred to the filter 6 as shown in FIG.
from the feed pipe 5 to the fuel supply device 1
5.

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

Here, the end of the return pipe 7 is connected to the ejector pump 13.
Since the nozzle 8 is formed in the chamber 9 constituting the nozzle 8, the discharge pressure of the feed pump P causes the fuel to flow from the nozzle 8 to the constricted part 10. It is vigorously ejected toward the throat portion 11. Therefore, a negative pressure is generated around the nozzle 8 in the chamber 9, and this negative pressure causes the fuel in the auxiliary chamber 4 to be sucked into the chamber 9 via the communication vibe 12, and together with the jet from the nozzle 8. The flow rate is increased by the throttle part 10 and the fuel is fed from the throat part 11 into the main chamber 3, where an ejector action occurs, and the fuel in the sub-chamber 4 is returned to the main chamber 3 as excess fuel returns to the tank body l. transferred within.

Here, the fuel injected from the nozzle 8 is swirled within the nozzle 8 by the swirling piece 100 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 acts on the communication pipe 12 side without loss, and therefore the nozzle 8
Compared to the case where fuel is injected in spots from the fuel tank, the suction force of the fuel can be substantially increased, and the time required to suck up the fuel from the auxiliary chamber 4 can be shortened.

Specifically, the turning piece 100 and the ejector pump 1
Since each dimension of No. 3 is set so as to exhibit the optimum ejector function, the ejector function can be sufficiently exerted even when the return flow rate is small.

Note that the embodiments of the present invention are not limited to those described above; for example, if the crossing angle of the swirling blades is within the set range, the swirling piece can be mounted on the upstream side as shown in Fig. 10.11. The tip may be formed into a flat shape. In addition, the ejector pump can be adjusted in various ways if the dimensions described above can be set.In the above embodiment, a return pipe was used as a guide pipe, but in order to return a portion of the fuel into the tank body, a feed pump may be used. A connected pipe may also be used.

As described in detail, according to the present invention, the nozzle protruding into the chamber of the ejector pump is provided with a diffusion device, and the crossing angle of the blades of the diffusion device is set to an optimum range. Even when the return flow rate is low, the fuel ejected from the nozzle diffuses and closes the lower side of the chamber below the nozzle, preventing air from being sucked in from the tapered opening. It should be possible to exert the ejector action efficiently by applying it to the suction pipe without pressure loss.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is an overall sectional view, FIG. 2 is an enlarged sectional view of the main part of FIG. 1, FIG. 3 is a graph, and FIG. 4 is a perspective view of a turning piece. , Figures 5 to 8 are a front view, top view, side view, and rear view of the turning piece, respectively, Figure 9 is a fuel supply system diagram, and Figures 10 and 11 are perspective views showing other embodiments of the turning piece. Figure and front view. 7... Return vibe (induction pipe), 8... Nozzle, 9... Chamber, 10... Throttle part, 11...
Throat part, 12...Communication pipe (suction pipe), 1
3...Ejector pump, +00...Swivel piece (
Diffusion device), 100b... wing section (wing), 0... crossover fQ degree. 2 other people Figure 1 7 ---- Return pipe (sometimes via eye 8...
- Noz J 9 - - Chicken 7 M 13 - - 11 Evicta Pump e - - One cross 9 degrees Fig. 3 Intersecting angle □ Fig. 4 Fig. 6

Claims (1)

[Claims] (1) A guide pipe and a suction pipe are provided, a nozzle is formed at the end of the guide pipe, and a chamber containing the nozzle and communicating with the suction pipe is formed;
A fuel suction device for a fuel tank including an ejector pump in which a constriction part and a throat part following the constriction part are formed below the nozzle of the chamber, and the nozzle is provided with a pair of wings that diffuse and eject fuel. A fuel suction device for a fuel tank, characterized in that a diffusion device is installed inside and the crossing angle of the blades is set to 140° or less.