JPS63192999A - Ejector pump of fuel tank device for vehicle - Google Patents

Abstract

PURPOSE:To effectively exhibit the action of an ejector without widening the working hole of a tank body by setting the length of a throat portion connecting with the lower side of a vacuum chamber containing a nozzle specific times larger than the inlet diameter of the throat portion. CONSTITUTION:An ejector pump 9 is constructed in a small size of width by connecting an upper plate 20, having a leading pipe connecting portion 22 and an intake pipe connecting portion 23, integrally projected upward in parallel to a lower plate 21 in which a vacuum chamber 30 containing a nozzle 28, an introducing portion 31 and a discharge portion are formed in one body. And the inlet diameter D of a throat portion 32 connecting with the lower side of the vacuum chamber 30 is set to nearly d/D=0.2-1 in relation to the inner diameter d of the nozzle 28, and the length L of the throat portion 32 is set 2-8 time as long as the inlet diameter D. Accordingly, a working hole provided on a tank body can be small and also it is possible to always obtain the optimum action of an ejector.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an ejector pump for a vehicle fuel tank system.

Conventional technology Some fuel tank devices for automobiles include, for example,
As shown in Publication No. 65057, due to the structure of the part on which the tank body is mounted, an inwardly bulging portion is formed on the bottom wall of the tank body, and this bulging portion forms an abbreviation of the tank portion. Some have a main chamber and an auxiliary chamber separated in the lower half.

With this structure, when the remaining amount of fuel decreases and the fuel level drops, a large amount of fuel remains in the subchamber, so a feed pump is connected to the main chamber and a portion of the discharged fuel is A guide pipe for leading out the water and an ejector pump formed at the end of the guide pipe are provided, and a suction pipe having a suction port near the bottom of the auxiliary chamber is connected to the ejector pump. At the same time, the fuel in the main chamber is transferred to the fuel supply device of the engine, and at the same time, the fuel in the auxiliary chamber is transferred to the main chamber by the ejector action of the ejector pump.

Problems to be Solved by the Invention The aforementioned ejector pump has a guide pipe, a suction pipe,
It consists of four parts: a nozzle and a discharge pipe containing a negative pressure chamber. Moreover, the guide pipe, suction pipe, and discharge pipe each protrude from the negative pressure chamber including the nozzle in different directions, three directions in total. For this reason, when installing the ejector pump into the tank body through the work hole formed in the tank body, for example, if you try to pass the guide pipe and discharge pipe through the work hole with the guide pipe and discharge pipe facing up and down, the suction pipe will be placed horizontally. Since it protrudes in the direction, it is necessary to make the working hole large enough to allow the suction pipe to pass through. However, if the working hole is made larger, the strength of the tank body may be reduced.

Therefore, the present invention provides a fuel tank device for a vehicle that can be installed without hindering workability, that can improve the strength of the tank body by reducing the size of the working hole, and that can ensure efficient ejector action. The present invention provides an ejector pump.

Means for Solving the Problems A guide pipe connection section and a suction pipe connection section are provided, and a nozzle is provided at the lower end of the guide pipe connection section, and a negative pressure chamber containing the nozzle and a negative pressure chamber from the suction pipe connection section are provided. In an ejector pump for a fuel tank device for a vehicle, which is provided with an introduction part leading to a chamber and a throat part continuous to the lower side of this negative pressure chamber, the length of the throat part is 2 times the inlet diameter of the throat part.
It is set to ~8 times.

By reducing the range of interference between the connecting part and the suction pipe connecting part of the inhalation guide vibrator to the working hole, it is possible to prevent the working hole from increasing in diameter, and the ejector function can be exerted most efficiently.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

In Figures 1-4,! indicates a tank body, and a bulge 2 is formed inward at approximately the center of the bottom wall, and a main chamber 3 and a sub-chamber 4 are separated from each other in approximately the lower half of the tank body l. has been done. This main chamber 3 upper blade tanshi body! ! ! ! A working hole 5 is provided in the tank body 1 above the auxiliary chamber 4.
Another working hole 6 is provided in the wall.

An outlet pipe 10 connected to a fuel supply device (not shown) is inserted into the main chamber 3 from the working hole 5,
A feed pump 7 is connected to the tip of this outlet pipe 10. In addition, 16 is a filter for the feed pump 7, 13 is a lid that closes the working hole 5, and 14 is this lid! A stay fixed to 3 and supporting the feed pump 7 is shown.

Further, a guide pipe 8 connected to a fuel supply device (not shown) is inserted into the main chamber 3, and a suction pipe 11 is inserted into the subchamber 4 from the working hole 6 on the side of the subchamber 4. The other end is inserted, and an ejector pump 9, which will be described later, is connected to the guide pipe 8 and the suction pipe 11. Furthermore, 1
Reference numeral 5 indicates the lid of the working hole 6 on the side of the subchamber 4, and reference numeral 12 indicates a filter attached to the suction port Za of the suction pipe 11.

The ejector pump 9 uses a jet flow when surplus fuel of the fuel sent from the feed pump 7 to the fuel supply device returns into the main chamber 3 along the guide pipe 8 into the ejector pump 9. A negative pressure region is formed, and this negative pressure causes the fuel in the auxiliary chamber 4 to flow through the suction pipe 11 to the main chamber 3.
It was designed to lead to.

This ejector pump 9 will be specifically explained.

In FIG. 1.2, the ejector pump 9 is made of oil-resistant resin, and has a guide pipe connection part 22 and a suction pipe connection part 23 that are formed upward in parallel and integrally. an upper plate 2° with a nozzle 28 formed at its lower end; a negative pressure chamber 30 coaxially containing the tip of the nozzle 28; and the suction pipe connecting portion 2.
A lower plate 21 is provided in which an introduction part 3 connecting from 3 to a negative pressure chamber 30 and a throat part 32 connected to the lower side of this negative and positive chamber 3o are integrally formed.

Then, the four portions 29 formed on the periphery of the lower surface of the upper plate 2o and the convex portion 33 formed on the periphery of the upper surface of the lower plate 21 are fitted together to connect the upper plate 20 and the lower plate 2. Accordingly, the negative pressure chamber 30. The introduction section 31 is separated.

Flanges 24.25 are formed at the upper edges of the guide pipe connection part 22 and the suction pipe connection part 23 of the upper plate 20, respectively, and seal receiving parts 26.27 are formed at the inner peripheral edges of these flanges 24.25. There is.

On the other hand, a relief valve 60 for opening and closing the communication hole 35 provided in the guide pipe connection part 22 is provided in the branch boat 34 at a vertically intermediate portion of the guide pipe connection part 22 .

The flanges 24 of the guide pipe connection part 22 and the suction pipe connection part 23 of the plate 20 configured in this way.
A pipe socket 3G is attached to 25 via seal rings 54 and 55.

The pipe socket 36 has the seal ring 54.5.
5, a guide pipe socket part 37 which is in close contact with the flanges 24 and 25 of the guide pipe connection part 22 and the suction pipe connection part 23, a suction pipe socket branch 38, and a bridge part 39 which connects these parts. ing.

A plurality of slits 40 and 41 are formed at regular intervals in the circumferential direction in the lower halves of the guide pipe socket part 37 and the suction pipe socket part 38, and claw parts 44 and 45 are provided between the slits 40 and 41. Elastic pieces 42, 43 are each formed. Moreover, small-diameter cylindrical pipe adapter parts 4G and 47 are provided at the upper openings of the guide pipe socket part 37 and the suction pipe socket part 38, and the guide pipe 8 and the inner wall of the pipe adapter parts 46 and 47 are provided with Suction pipe 1
A recess 5 that receives a protrusion 56,58 formed on the outer wall of 1
0,51 are formed.

Incidentally, the pipe adapter portions 46 and 47 are formed with slits 52 and 53 for smoothly receiving the guide pipe 8 and the suction pipe 11.

Further, on the inner circumferential wall of the seal ring 54,55, a seal lip portion 54a that is in close contact with the guide pipe 8 and the suction pipe 11,
55a is formed.

The guide pipe socket part 37 and the suction pipe socket part 38 are connected by a bridge part 39 having connecting walls 48,49 between each pipe adapter part 413,47.

Here, regarding the length of the throat portion 32 of the lower plate 21, L/D (throat ratio) is set to 2 to 8, where D is the inner diameter as the inlet diameter of the throat portion 32. Note that if the throat ratio (L/D) is smaller than the above range, a gap will be created between the throat part 32 and the jet when the jet from the nozzle 28 flows through the throat part 32, and the negative pressure chamber will flow from this part. Outside air is introduced into the 30, canceling out the negative pressure effect, making it impossible to exert the ejector action, and conversely reducing the throat ratio (L
/D) is larger than the above range, boiling under reduced pressure occurs at the tip of the nozzle 28, generating vapor and increasing internal pressure, which may impede the ejector action and, in some cases, cause the flow path in the throat portion 32 to The resistance may increase and the fuel may flow backward from the introduction section 31 to the suction pipe connection section 23.

The results revealed through experiments to determine the throat ratio (L/D) are shown in Figure 5, where the horizontal axis is the throat ratio (L/D) and the vertical axis is the suction amount (i2/hr). , the excess fuel led out to the guide pipe 8 is at room temperature (20
℃; shown by the solid line) and high temperature (00°C; shown by the broken line), in order to secure the required suction 11 m around 10 (12/hr), the throat ratio (L/hr) is required at both room temperature and high temperature. It was confirmed that cases where D) is 2 to B are preferable.

At this time, the ratio (d/D) between the inner diameter d of the nozzle 28 and the inner diameter of the throat portion 32 was set to 0.2 to 1, and the surplus fuel flow m was set to about 80 (12/hr).

Furthermore, although the amount of surplus fuel varies from moment to moment depending on the driving state of the engine, it has been confirmed that the amount of suction in this case can be secured to be about 3 to 4 times the amount of surplus fuel when the surplus fuel is at room temperature.

According to the structure of the above embodiment, when the feed pump 7 is driven, the fuel in the main chamber 3 is sucked in through the filter 16 and transferred to the engine fuel supply device (not shown) through the outlet pipe IO. Since not all of the discharged fuel is consumed in the fuel supply system, surplus fuel is led to the guide pipe 8 from the engine's fuel supply system (not shown). The fuel led to the guide pipe 8 is ejected from the nozzle 28 through the guide pipe connecting portion 22 by the discharge pressure of the feed pump 7 toward the inlet of the throat portion 32 via the negative pressure chamber 30 of the ejector pump 9. This ejection of fuel from the nozzle 2B generates negative pressure in the negative pressure chamber 30, and this negative pressure causes the fuel in the sub chamber 4 to flow from the suction pipe 11 to the suction pipe connecting portion 23. The fuel is sucked into the negative pressure 1430 through the introduction part 31 and transferred into the main chamber 3 through the throat part 32 together with the fuel jetted from the nozzle 28 .

In this case, by appropriately setting the throat ratio (L/D), a constant suction amount is ensured regardless of the temperature of the fuel, and the ejector action is performed smoothly.

On the other hand, the ejector pump 9 is assembled with the upper plate 20 and the lower plate 21 by hermetically fitting the concave portion 29 and the convex portion 33, respectively, so that the assembly is easy and highly reliable.

Further, since the upper portions of the guide pipe connecting portion 22 and the suction pipe connecting portion 23 are connected to each other by the pipe socket 36 in which the guide pipe socket portion 37 and the suction pipe socket portion 38 are connected by the bridge 39, the guide pipe 8
Or an inhalation pipe! 1, it is possible to prevent the guide pipe connection part 22 and the suction pipe connection part 23 from breaking from the root part by an external force F as shown in FIG.

Moreover, by making the diameters of the guide pipe 8 and the suction pipe 11 different, the guide pipe 8 and the suction pipe 11 can be
The diameters of the pipe receiving parts 57.59 and pipe adapter parts 46.47 to which the guide pipe 8 is fitted and installed are also different.
And an inhalation pipe! It is also possible to prevent incorrect assembly. Since the ejector pump 9 has a simple structure and is lightweight, it can be supported only with the pipe socket 36, eliminating the need for a special bracket, improving installation workability, and ensuring sufficient tank space. It is possible to make the diameter smaller.

FIG. 6 shows a different example of the present invention, in which a branch socket 61 is interposed in the part of the outlet pipe 10 located inside the tank body 1, and the guide pipe 8A is connected to the branch socket 61. The guide is designed to prevent the Eve 8A from being exposed outside the tank body l.

Effects of the Invention As described above, according to the present invention, the upper plate, in which the guide pipe connection part and the suction pipe connection part are integrally projected upward in parallel, is connected to the negative pressure chamber, the introduction part, and the discharge part. Since the part is connected to the integrally formed lower plate,
The width can be made smaller than that in which the guide pipe and suction pipe protrude in two directions.

As a result, the working hole in the tank body can be made smaller, which improves the strength of the tank body.In addition, the area occupied by the ejector pump in the tank body is reduced, so the feed pump and induction pump inside the tank body can be reduced. pipe,
It is also possible to improve component arrangement including other functional components. Since multiple pipes such as guide pipes and suction pipes can be connected in one direction, assembly workability is improved.

Furthermore, since the guide pipe connection part and the suction pipe connection part are parallel, when molding the ejector pump, the mold shape is simple and moldability is good.

In addition, because the length of the throat section is set to the optimum value in relation to the throat inlet diameter, optimal ejector action is always ensured regardless of the fuel temperature situation, further increasing reliability. effective.

[Brief explanation of the drawing]

FIG. 1 is an exploded vertical cross-sectional view showing the main parts of an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view showing the main parts of the embodiment assembled.
Fig. 3 is a schematic side view showing the assembly of the main parts of the embodiment, Fig. 4 is a schematic configuration diagram showing the entire embodiment, Fig. 5 is a graph, and Fig. 6 is another embodiment. It is a schematic block diagram of an example. ! ...Tank body, 9...Ejector pump, 22.
...Induction pipe connection part, 23...Suction pipe connection part,
28... Nozzle, 30... Negative pressure chamber, 3! ...Introduction part, 32...Throat part, I...Length of throat part, D...Inner diameter of throat part (inlet diameter). Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] (1) A guide pipe connection section and a suction pipe connection section are provided, and a nozzle is provided at the lower end of the guide pipe connection section, a negative pressure chamber containing the nozzle, and an introduction section leading from the suction pipe connection section to the negative pressure chamber. In an ejector pump for a vehicle fuel tank device, which is provided with a throat section connected to the lower side of the negative pressure chamber, the length of the throat section is set to be 2 to 8 times the inlet diameter of the throat section. Features: Ejector pump for vehicle fuel tank equipment.