JPH0341085Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a vapor removal device for an in-tank fuel pump.

<Prior Art> In conventional internal combustion engines for automobiles, an electric fuel pump is provided in the fuel tank, and fuel is supplied to the engine by the fuel pump (see Utility Model Application No. 59-110373). reference).

As a conventional fuel pump, one shown in FIG. 2 is known.

That is, in a cylindrical casing 1, a plurality of grooves 5 are formed in a peripheral portion rotatably supported by a fixed shaft 4 in a pump housing 3 having a fuel suction port 2 and a fuel discharge port (not shown). A pump section 7 that houses an impeller 6 and an electric motor 8 that rotationally drives the impeller 6 disposed above the pump section 7 are housed.

By supplying power to the armature 10 from a battery (not shown) via the brush 9 and the commutator 10a formed on the armature 10, the armature 10 generates rotational force, and the rotational force is transmitted to the impeller 6 via the joint member 11. to rotate the impeller 6. Then, by the action of the groove 5 of the impeller 6, the fuel in the fuel tank is sucked into the casing 1 from the fuel suction port 2, and from the fuel outlet 13 (not shown) formed in the upper part of the casing 1 and equipped with a check valve 12. Supply to institutions.

Furthermore, a vapor removal passage 14 is formed at the upper end of the casing 1 and communicates between the inside of the casing 1 and the inside of the fuel tank. and a protrusion 1 formed on the valve body 16.
An on-off valve 18 consisting of an outer cylindrical member 17 into which the valve 6a is loosely inserted is interposed.

With the on-off valve 18 interposed in this way, when the vapor inside the casing 1 is in contact with the on-off valve 18, the valve body 16 moves downward in the figure due to the biasing force of the spring 15, and the end face 16c of the valve body 16 moves downward in the figure. and the end surface 17a of the outer cylinder member 17 are maintained separated from each other. Then, the vapor inside the casing 1 is removed from the valve body 1.
The vapor accumulated in the upper part of the casing 1 is discharged into the fuel tank through the groove 16b formed in the casing 16 and the gap formed between the valve body 16 and the outer cylinder member 17, and the vapor accumulated in the upper part of the casing 1 enters the engine from the fuel outlet 13. It prevents it from being supplied.

On the other hand, when the liquid fuel pumped by the pump section 7 attempts to pass through the on-off valve, the valve body 16 moves upward in the figure due to the fluid resistance of the liquid fuel, and the end surface 16c of the valve body 16 and the end surface 17a of the outer cylinder member 17 are in contact with each other to shut off the inside and outside of the casing 1, thereby preventing fuel leakage and reducing the discharge performance of the pump.

<Problems to be solved by the invention> However, in such a conventional in-tank fuel pump, if the fuel pump is stopped for a long time with the liquid level lower than the on-off valve 18, the inside of the casing 1 The user is exposed to air entering through the open/close valve 18 which is in the open state for a long time. When such a state is repeated, the outer surface of the commutator 10a disposed within the casing 1 gradually oxidizes, which may cause a failure in power supply to the armature 10.

The present invention was developed by focusing on these problems of conventional in-tank fuel pumps, and aims to provide a vapor removal device for in-tank fuel pumps that can prevent power supply failures due to oxidation of the commutator. do.

<Means for Solving the Problems> For this reason, in a conventional vapor removal device for an in-tank fuel pump, the vapor removal passage on the downstream side of the on-off valve and the vicinity of the bottom wall of the fuel tank are communicated by a hollow member.

<Operation> Since the above-described configuration is adopted, even if the liquid level falls below the on-off valve, fuel remains in the hollow member, and this residual fuel blocks the inside and outside of the casing. Therefore, air can be prevented from entering the casing, and oxidation of the commutator and, ultimately, failure of power supply to the armature can be prevented.

<Example> FIG. 1 shows an example according to the present invention. In addition,
Elements similar to those in the conventional example are designated by the same reference numerals and description thereof will be omitted.

One end of an inverted J-shaped hollow member 20 is connected to the vapor removal passage 14 on the downstream side of the on-off valve 18, and the other end of the hollow member 20 is located near the bottom wall 19 of the fuel tank. For this reason, the liquid level is lower than the fuel tank bottom wall 1.
Fuel will definitely remain in the hollow member 20 until the temperature drops to around 9.

Note that the hollow member 20 is attached to the outer periphery of the casing with a tubular band 21 made of rubber.

Since such a configuration is adopted, even if the on-off valve 18 is maintained in the open state due to the vapor inside the casing 1 when the liquid level is lowered and is below the on-off valve 18, the inside of the hollow member 20 is The airtightness inside and outside of the casing 1 is maintained by the residual fuel. For this reason,
Air enters the casing 1 and the commutator 10
A is not oxidized, and defective power supply to the commutator 10 can be prevented.

In addition, in the embodiment, the on-off valve 18 is connected to the casing 1.
Although the vapor removal passage 14 formed at the upper end is interposed, if the upper part of the casing is where vapor easily accumulates, a vapor removal passage is formed on the upper side of the casing 1, and an on-off valve 18 is interposed in the vapor removal passage. It may be something.

Further, in the embodiment, the pump section 7 is constructed using an impeller, but the same effect can be obtained even if the pump section 7 is constructed using a well-known pump such as a roller vane.

<Effects of the invention> As explained above, according to the invention, the vapor removal passage on the downstream side of the on-off valve and the vicinity of the bottom wall of the fuel tank are communicated with each other through the hollow member. can be blocked,
It is possible to prevent power supply failures to the armature due to oxidation of the commutator.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of one embodiment of the present invention;
The figure is a sectional view of a conventional in-tank fuel pump. 1...Casing, 2...Fuel suction port, 7...
Pump part, 8...Electric motor, 13...Fuel outlet, 14...Vapor removal passage, 18...Opening/closing valve,
19...Fuel tank bottom wall, 20...Hollow member.

Claims (1)

[Scope of utility model registration request] A pump part including a fuel suction port and a fuel discharge port, a casing provided to cover the fuel discharge port of the pump part and having a fuel outlet formed in the upper part thereof, and a casing disposed inside the casing to support the pump part. A driving electric motor, a vapor removal passage formed in the casing portion, and an on-off valve interposed in the vapor removal passage that maintains an open state due to the fluid resistance of the vapor and closes due to the fluid resistance of the liquid fuel. In the vapor removal device for an in-tank fuel pump, the in-tank fuel pump is characterized in that a hollow member is provided that communicates the vapor removal passage on the downstream side of the on-off valve with the vicinity of the bottom wall of the fuel tank. Vapor removal device.