JPH0732935Y2 - Fuel pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a fuel pump suitable for use in, for example, supplying fuel in a fuel tank to an automobile engine, and more particularly to a fuel pump generated in the fuel pump. The present invention relates to a fuel pump equipped with a hot restart valve that discharges vapor to the outside.

[Prior art]

FIGS. 4 to 5 show examples in which a fuel pump according to the prior art is mounted in a fuel tank of a vehicle.

In the figure, 1 is a fuel pump mounted in a fuel tank via a mounting bracket (neither is shown), 2 is a cylindrical casing that constitutes the main body of the fuel pump 1, and inside the casing 2, A motor unit including an electric motor such as a DC motor and a roller vane type or turbine type pump unit (neither is shown) rotatably driven by the motor unit are provided. In addition, the casing 2
A suction port (not shown) communicating with the pump portion is formed at the lower end side of the pump, and a filter (neither is shown) is provided at the suction port via a suction pipe. The fuel pump 1 sucks the fuel in the fuel tank from the suction port into the pump unit through the filter and the suction pipe by the rotation of the motor unit, and discharges the fuel from a discharge port 4 described later to the outside. .

Reference numeral 3 denotes an upper cover which forms a part of the casing 2 and is provided on the upper end side of the casing 2 and is formed in a lid shape from a resin material or the like. Discharge port 4 for discharging the fuel of the above toward an external pressure regulator, a fuel injection valve (neither is shown), etc.
A relief valve 5 that opens when the pressure inside the casing 2 reaches a predetermined pressure to allow fuel to escape to the fuel tank side, and a pair of power supply terminals 6 and 7 for supplying power to the motor section from the outside.
A hot restart valve 8 to be described later is provided.
Also, as shown in FIG. 5, the upper cover 3 is formed with a pair of recesses 3A, 3A on the outer peripheral side, and each recess 3A makes the thickness of the upper cover 3 uniform and suppresses deformation during molding. It has become.

Reference numeral 8 denotes a hot restart valve provided at the vapor discharge port 3B of the upper cover 3, and the hot restart valve 8 is fixed in the vapor discharge port 3B via a stopper washer 9 as shown in FIG. , A stepped cylindrical valve seat member 10 having a valve seat 10A formed on the lower end side, a valve body 11 which is seated on and off the valve seat 10A to open and close the vapor discharge port 3B, and the valve body 11
And a valve seat member 10, and is normally composed of a valve spring 12 that holds the valve body 11 in an open state. The valve body 11 has a pressure in the casing 2 of, for example, 0.2 kg / cm. ^When it exceeds about ² , the valve is closed against the valve spring 12. Also,
An upper end side of the valve seat member 10 projects upward, and a base end side 13A of a vapor discharge pipe 13 described later is connected to the protruding end side. The hot restart valve 8 is adapted to discharge the vapor generated in the casing 2 into the fuel in the fuel tank through the vapor discharge pipe 13 at the time of starting the motor part for the reason described below. Indicated at 13 is a vapor discharge pipe composed of an elastic hose or the like, the base end side 13A of which is connected to the hot restart valve 8 and the tip end side 13B of which is connected to the filter 14. It is bent in a letter shape and extends from the upper end side of the casing 2 toward the lower end side along the outer peripheral surface, and the front end side 13B
Is fixed to the outer periphery of the casing 2 with a fixing band 15 made of resin in a state in which is directed toward the bottom side of the fuel tank. And
The vapor discharge pipe 13 guides the vapor in the casing 2 discharged from the hot restart valve 8 into the fuel in the fuel tank, and muffles the discharge sound at the time of discharging the vapor.

The fuel pump 1 according to the prior art has the above-described structure. When the motor part is supplied with power from the power supply terminals 6 and 7 to rotate the pump part when the engine is started, the fuel in the fuel tank is filtered by a suction pipe. Is sucked into the pump section through the suction port. Then, this fuel is supplied under pressure from the discharge port 4 to the fuel injection valve of the engine through the periphery of the motor section.

By the way, when the remaining amount of fuel in the fuel tank becomes small and the casing 2 projects beyond the oil level of the fuel, the fuel in the casing 2 flows out to the fuel tank side after the driving of the pump unit is stopped, and the inside of the casing 2 becomes negative pressure. At the same time, the motor cannot be cooled by the fuel, and the heat from the motor causes the inside of the casing 2 to reach a high temperature. Therefore, vaporization easily occurs in the casing 2 due to vaporization of fuel.

Therefore, a hot restart valve 8 is provided on the upper end side of the fuel pump 1, and a vapor discharge pipe 13 having a filter 14 attached to the front end side 13B is connected to the valve 8 so that the vapor in the casing 2 is removed from the fuel tank. By discharging into the fuel, the so-called vapor lock of the engine is prevented, and the inside of the casing 2 is shut off from the outside air through the vapor discharge pipe 13 or the like to prevent the inside of the casing 2 from being dried by the outside air. ing.

[Problems to be solved by the invention]

By the way, in the above-mentioned prior art, the vapor discharge pipe
Since the fixing band 15 is fastened to the outer peripheral side of the casing 2 by the fixing band 15, when the fixing band 15 is swollen by the fuel, the position of the vapor discharge pipe 13 is changed to contact the mounting bracket. Or the vapor discharge pipe 13 may be deformed at a portion 13D shown in FIG. Further, when the remaining amount of fuel in the fuel tank becomes low, the filter 14 and the like may be exposed from the liquid surface of the fuel, and outside air may enter the vapor discharge pipe 13.

Therefore, in the conventional technique, the fuel vapor generated in the casing 2 is transferred from the hot restart valve 8 to the vapor discharge pipe.
There is a possibility that the fuel cannot be normally discharged into the fuel through the motor 13 and that the inside of the casing 2 is dried by the outside air that has entered from the vapor discharge pipe 13 and an oxide film is formed on the commutator, brush, etc. Of the fuel pump, and the reliability and life of the fuel pump are significantly reduced.

Moreover, since the vapor is discharged into the fuel in the fuel tank through the vapor discharge pipe 13, the vapor discharge pipe 13
It is necessary to make the length longer and fasten it to the casing 2 with a fixed band, which results in a problem that the manufacturing cost of the fuel pump 1 and the number of assembly steps increase.

The present invention has been made in view of the above-mentioned problems of the prior art. The present invention can stably discharge the vapor of the fuel for a long period of time, and reliably prevents the occurrence of vapor lock and the drying of the casing due to the outside air. The present invention provides a fuel pump capable of improving workability at the time of assembly and greatly improving reliability and life.

[Means for Solving the Problems]

The feature of the structure adopted by the present invention to solve the above-mentioned problems is that a fuel pool for accumulating fuel is provided inside the upper end of the casing, and the tip side of the hot restart valve is inside the fuel in the fuel pool. The vapor discharge pipe is provided to discharge the vapor from the hot restart valve into this fuel.

[Action]

With the above structure, the paper of the fuel generated in the casing can be discharged from the hot restart valve into the fuel in the fuel reservoir through the vapor discharge pipe, and the fuel in the fuel reservoir can discharge the inside of the casing to the outside air. The shutoff can be continued, and the inside of the casing can be prevented from being dried by the outside air.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

In the figure, 21 indicates a fuel pump according to the present embodiment, which is substantially the same as the fuel pump 1 described in the prior art,
Although generally composed of a cylindrical casing 22 containing a motor part and a pump part (neither shown),
An upper end side of the casing 22 extends upward by a predetermined length to form a cylindrical fuel pool 23 having an open upper end surface on an upper surface side of an upper cover 24 described later. And the fuel pool 23
Fuel is replenished from the outside when the fuel tank is refueled, etc., so that a predetermined amount of fuel is reserved and secured even when the fuel remaining amount in the fuel tank becomes small, and the inside of the vapor discharge pipe 30 described later is This fuel shuts off the inside of the casing 22 and the outside air. (See Figure 3).

Reference numeral 24 denotes an upper cover forming a part of the casing 22, and the upper cover 24 is similar to the upper cover 3 described in the prior art, and has a discharge port 25, a relief valve 26, power terminals 27 and 28,
Although a hot restart valve 29 is provided,
As shown in FIG. 2, the upper cover 24 is formed with a pair of recesses 24A, 24A having a diameter larger than that of each recess 3A described in the prior art and filled with fuel. Then, a filter 31 of a vapor discharge pipe 30 described later is inserted into one of the recesses 24A of the recesses 24A, and a fuel pool is always provided around the filter 31.
It is designed to secure the fuel in 23.

Reference numeral 30 denotes a vapor discharge pipe made of a resin material or the like in which the base end side 30A is connected to the hot restart valve 29 and the tip end side 30B is integrally provided with a filter 31.
Is formed in an inverted "S" shape by bending the intermediate portion 30C in an inverted U shape. As shown in FIG. 3, the vapor discharge pipe 30 inserts the filter 31 into the recess 24A of the upper cover 24 to remove the vapor of the fuel in the casing 22 discharged from the hot restart valve 29 into the filter 31. The gas is discharged into the fuel in the fuel pool 23 through the so that the sound emitted when the vapor is discharged is silenced and the inside of the casing 22 is prevented from being dried by the invasion of the outside air.

The fuel pump according to the present embodiment has the above-mentioned configuration, and the basic operation thereof is not different from that of the prior art.

Therefore, in the present embodiment, the fuel pool 23 for storing fuel is formed on the upper end side of the casing 22, and the hot restart valve 29 has the filter 31 on the tip side 30B located in the recess 24A of the upper cover 24. Is immersed in the fuel in the fuel pool 23,
Since the vapor discharge pipe 30 for discharging the vapor generated in the casing 22 into the fuel from the hot restart valve 29 is provided, the vapor in the casing 22 is stably discharged into the fuel in the fuel pool 23 for a long period of time. Therefore, it is possible to effectively prevent the occurrence of a vapor lock or the like of the engine, and it is possible to reliably prevent the inside of the casing 22 from being dried by the outside air by shutting off the inside of the casing 22 from the outside air by the fuel in the fuel sump 23. Therefore, it is possible to reliably prevent the formation of an oxide film on the commutator or brush of the motor section.
The reliability and life of the fuel pump 21 can be significantly improved, and the vapor discharge pipe 30 has a filter 3 on the tip side 30B.
1 can be easily attached to the hot restart valve 29 in an integrated state, improving workability during assembly,
Various effects can be obtained such that the whole can be formed compactly.

Incidentally, in the above-mentioned embodiment, the vapor discharge pipe 30 is located in the middle portion 30C.
Bend it in an inverted U shape to form an inverted "S" shape.
Although it has been described that the filter 31 of B is inserted and installed in the recess 24A of the upper cover 24, instead of this, the paper discharge pipe is replaced.
The 30 may be formed in another shape such as an inverted U shape or a short rod shape, and the filter 31 is placed on the upper surface of the upper cover 24 or fixed by using a fixing member such as a claw member or an adhesive. In this case, the upper end side of the casing 22 may be extended upward to form the fuel pool 23 deeply, and the vapor discharge pipe 30 may be replaced with the vapor from the hot restart valve 29. It is sufficient that the fuel can be discharged into the fuel in the fuel pool 23.

Further, in the above-described embodiment, the fuel pool 23 is described as being formed in a cylindrical shape having the upper end side of the casing 22 elongated for a predetermined length and having an open upper end surface, but the present invention is not limited to this.
For example, in order to integrally form the fuel sump 23 with the upper cover 24, the upper cover 24 may be formed into a bottomed cylindrical shape with an open upper end surface, and the fuel sump 23 will only have a small amount of fuel remaining in the fuel tank. Even if it does, the fuel is accumulated inside, and this fuel shuts off the air inside the casing 22 and the outside, and
It suffices if the tip 30B side of the vapor discharge pipe 30 can be immersed in this fuel.

Further, in the above-described embodiment, it is described that the fuel is replenished and stored in the fuel reservoir 23 from the outside when the fuel tank is refueled, but instead of this, for example, the return oil from the return pipe is stored in the fuel reservoir 23. Into the fuel pool
The fuel may be replenished and stored in the fuel tank 23. In this case, the fuel can be more reliably reserved in the fuel tank even when the remaining fuel amount in the fuel tank is low.

[Effect of device]

As described in detail above, according to the present invention, a fuel pool for accumulating fuel is provided at the upper end side of the casing, and the hot restart valve has its tip side immersed in the fuel in the fuel pool and is Since a vapor discharge pipe for discharging this vapor into the fuel is provided, the fuel vapor generated in the casing is stably discharged into the fuel in the fuel pool from the hot restart valve through the vapor discharge pipe for a long period of time. In addition, it is possible to prevent vapor lock of the engine and to block the inside of the casing from outside air and the like, thereby preventing the inside of the casing from being dried and preventing an oxide film from being formed on the motor part. , Various effects are exhibited.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention, FIG. 1 is a perspective view of a fuel pump, FIG. 2 is a plan view of the fuel pump, and FIG. 3 is an arrow III-III in FIG. FIG. 4 is a perspective view of the fuel pump, FIG. 5 is a plan view of the fuel pump, and FIG. 6 is an enlarged view of a hot restart valve and the like. FIG. 21 …… Fuel pump, 22 …… Casing, 23 ………… Fuel sump, 29 …… Hot restart valve, 30 …… Vapor discharge pipe, 31 …… Filter.

Claims (1)

[Scope of utility model registration request] 1. A fuel pump comprising: a casing containing a motor unit and a pump unit; and a hot restart valve provided on an upper end side of the casing for discharging vapor of fuel generated in the casing to the outside. A fuel reservoir for accumulating fuel is provided on the upper end side of the casing, and the tip end side of the hot restart valve is immersed in the fuel in the fuel reservoir, and the vapor from the hot restart valve is placed in this fuel. A fuel pump comprising a vapor discharge pipe for discharging.