JPH11324840A - Antistatic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent electric discharge between a delivery side hose and its peripheral devices, and to improve durability of the delivery side hose. SOLUTION: The device is equipped with a delivery side hose 4 which has a resin pipe portion 21 for supplying fuel from a fuel tank of a vehicle to an engine side and a cover pipe portion 22 comprising a conductive resin or a conductive rubber for covering this pipe portion 21; a conductive return pipe 8 for returning return fuel from an engine to the fuel tank, and a connecting means 27 for connecting the cover pipe portion 22 with the return pipe 8 keeping the conductivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an antistatic device provided in a fuel supply system for supplying fuel from a fuel tank to an engine.

[0002]

2. Description of the Related Art A fuel supply system of a vehicle sucks fuel in a fuel tank by a pump through a filter in the tank, and pressurizes the fuel by a pump through a discharge side hose and a high-pressure pipe supported on the vehicle body side. Supply to the engine. The remainder of the fuel consumed by this engine is returned to the fuel tank via a low-pressure return pipe and low-pressure hose. Here, the fuel tank is provided with a discharge-side curved pipe and a return-side curved pipe for communicating between the inside and the outside of the tank, and a high-pressure pipe and a low-pressure pipe on the vehicle body side are connected to each curved pipe via a discharge-side hose and a return hose. You. The discharge side hose and the return hose are equipped so as to absorb the relative displacement and relative fluctuation between the high pressure pipe and the low pressure pipe fixed to the vehicle body side and the fuel tank side by utilizing the flexibility of the hose. These hoses are usually arranged in a gap between the upper wall of the fuel tank and the rear floor on the vehicle body side.

[0003] A pump unit is provided in the fuel tank, and when the fuel pump of the unit is driven, fuel is sucked in through a filter and discharged to a discharge side hose. At this time, if these fuel path constituent members are made of resin, the friction between the fuel main component hydrocarbon paraffin and the fuel path constituent members causes the separation of electrons from the hydrocarbon molecules, and as a result, the fuel becomes exactly As a result, the fuel path member is negatively charged. For example, when the discharge side hose is non-conductive, the whole area of the discharge side hose is negatively charged by fuel passing through the inside of the discharge side hose. In addition, the fuel filter, which is a fuel path constituent member provided in the fuel tank, is charged by the passage of the fuel, and the generated static electricity is also discharged by the pipe joint at the upper end of the pump module and the discharge side connected thereto. Hose is charged.

When the discharge hose is charged in this way, if the air insulation at that time is low, a weak discharge occurs in a state where the charge amount of the discharge hose is relatively small, and the static electricity of the discharge hose is eliminated. Therefore, excessive charging is unlikely to occur.

[0005]

However, when the air is extremely dry, the insulating properties of the air are increased, and the discharge side hose does not discharge static electricity into the air, and the static electricity cannot be removed from anywhere. When the state continues, the charge amount of the discharge side hose increases sequentially as the fuel flows. Eventually, if the discharge hose is excessively charged until it exceeds the insulating property between the discharge hose and the peripheral parts, a discharge with greater energy is generated between the discharge hose and the peripheral parts, and the discharge point of the discharge hose is discharged. Causes a problem that the resin deteriorates and the durability decreases.

If a plurality of locations on the discharge hose are connected to the conductive hose support on the vehicle body side, the static electricity at the portion facing the connecting portions of the discharge hose and at the vicinity thereof is conductive. The hose is diffused and erased from the hose support to the vehicle body side, and excessive charging of the entire discharge side hose is prevented, and the discharge between the discharge side hose and the vehicle body base side can be relatively reduced. However, if the fuel tank serving as a hose support portion is made of a resin, for example, static electricity generated on the discharge side hose is not eliminated from anywhere, and if the air is extremely dry, the discharge side hose may be used. In particular, the discharge between the discharge hose and the peripheral parts such as the rear floor tends to occur, which causes a problem that the durability of the discharge side hose is reduced.

An object of the present invention is to provide an antistatic device capable of preventing discharge between a discharge side hose and its peripheral parts and improving durability of the discharge side hose.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, a resin tube portion of a discharge side hose is covered with a skin tube portion made of conductive resin or conductive rubber. Since the skin tube portion and the conductive return tube are connected to each other while maintaining conductivity by the connecting means, when high-pressure fuel from the fuel tank is supplied to the engine side via the discharge side hose, the entire surface of the tube portion is generated. All of the generated static electricity is led from the conductive skin tube portion to the conductive return pipe, and through this return pipe, it is guided to the engine and the like from the conductive fuel pipe to eliminate static electricity. For this reason, it is possible to prevent the discharge side hose from deteriorating due to the discharge of the static electricity of the discharge side hose directly to peripheral components, and to improve the durability.
Furthermore, all the static electricity generated on the pipe portion can be eliminated by only an easy operation of connecting the discharge side hose and the return pipe while maintaining the conductivity by the connecting means, and the assembly operation cost can be reduced.

Preferably, the tube portion is a multilayer nylon tube, and the skin tube portion is formed of conductive solid rubber. In this case, since the tube portion is a multilayer nylon tube, the discharge side hose has pressure resistance, Due to the penetration resistance, sufficient durability as a high-pressure fuel pipe can be ensured, and since it has flexibility, the relative displacement between the fuel tank and the fuel pipe fixed to the vehicle body or the like can be absorbed. , Pipe connection work can be facilitated. Further, the discharge side hose and the return pipe may be directly joined to each other by the connecting means. In this case, the discharge side hose and the return pipe can be joined while maintaining conductivity only by directly joining the discharge side hose and the return pipe to each other by the connecting means, so that the pipe connecting work can be simplified, the connecting means used here can be simplified, and the cost can be reduced. Can be achieved.

[0010]

1 and 2 show an antistatic device to which the present invention is applied. This antistatic device is mounted on a fuel supply system A provided between a fuel tank 1 of an automobile and an engine 2 at a front portion of a vehicle body (not shown). The fuel supply system A draws the fuel in the fuel tank 1 into a fuel pump 3 in the tank, increases the pressure, supplies it to the engine 2 via a discharge hose 4 and a high-pressure pipe 5, and supplies the fuel to the fuel injection system 6 on the engine 2.
The remaining fuel not consumed in the above is returned to the fuel tank 1 through the low pressure pipe 7 and the return hose 8 which are return pipes.

The fuel tank 1 is disposed below the left and right frames 9, 9 at the rear of the vehicle body and the rear floor 12 stretched between the front rear floor cross member 10 and the rear rear floor cross member 11, and is long and juxtaposed longitudinally. It is fastened and supported by the front rear cross member 10 and the rear rear cross member 11 via the metal belt 13. This fuel tank 1 is resin-molded as a substantially rectangular hermetic container having a flat bottom wall 101 and an upper wall 102 shaped to avoid interference with the rear floor 12. At substantially the center of the upper wall 102 of the fuel tank 1, a pump module 14 is integrally mounted.

The pump module 14 is used for the fuel tank 1
A casing 141 disposed therein, a lid 142 molded of resin with the casing 141, a fuel filter 15 supported by the casing 141, a fuel pump 3 for sucking fuel through the filter, and a level supported by the casing 141. A curved high-pressure pipe 17, which is integrally connected to the gauge 16 and the lid 142 and penetrates the lid to guide the fuel from the fuel pump 3 to the outside. A low-pressure fuel is integrally connected to the lid 142 and penetrates the lid. And a socket 19 that is integrally connected to the lid portion 142 and penetrates through the lid portion to penetrate the lid portion and accommodates both the motor wiring for guiding the drive current to the motor (not shown) of the fuel pump 3 and the wiring of the level gauge 16. Prepare.

The lid 142 is formed in a shape to seal a hole (not shown) formed in the upper wall 102, and is bolted to the upper wall 102 with a sealing member (not shown) therebetween.

The fuel pump 3 is a circumferential pump and is driven by a motor (not shown) to guide the fuel sucked through the fuel filter 15 to the curved high-pressure pipe 17. The fuel filter filters the fuel in the fuel tank 1 with a filter member made of resin and supplies the filtered fuel to the fuel pump 3. A curved high-pressure pipe 17 communicating with a discharge port (not shown) of the fuel pump 3 has a distal end connected to the discharge side hose 4. The curved low-pressure pipe 18 arranged in parallel with the curved high-pressure pipe 17 on the lid 142 returns the end thereof to the hose 8.

As shown in FIG. 3, the discharge side hose 4 is formed of a resin tube portion 21 and a skin tube portion 22 formed of a conductive resin and covering the tube portion. The tube portion 21 here is formed of nylon resin in order to ensure pressure resistance. Moreover,
Considering the fuel permeability of the resin tube, the resin tube is multi-layered (not shown), and is configured to prevent intermolecular permeation of fuel. The skin tube portion 22 covering the tube portion 21 is made of solid rubber (EPDM) mixed with a conductive material.
Etc.). The skin tube portion 22 is for keeping the entire surface of the tube portion 21 conductive, and is formed to be relatively thin. The skin tube portion 22 may be formed of a conductive resin other than solid rubber.

A pipe joint 201 and a cylindrical nut 20 engaged with the pipe joint 201 are connected to one end of the discharge side hose 4, and the nut 20 is screwed to a threaded portion (not shown) at the tip of the curved high pressure pipe 17. The communication state is maintained.
The other end of the curved high-pressure pipe 17 is connected to a metal high-pressure pipe 5 fixedly supported on the vehicle body via a resin socket 23 as shown in FIG. A main body 231 of the resin socket 23 is integrally formed of resin (PP or the like), and a passage 232 penetrates in a longitudinal direction of the main body 231. Is press-fitted, and a fitting hole 233 is formed in the other. This fitting hole 2
Reference numeral 33 denotes an enlarged diameter portion 234 formed at the innermost portion. When the resin socket 23 is pushed into the high-pressure pipe 5, the annular bulging portion 501 of the high-pressure pipe 5 is relatively pushed to the enlarged diameter portion 234. Can be combined in a non-separable state. Reference numeral 24 indicates a seal member.

As described above, the discharge side hose 4 has pressure resistance and permeation resistance so that the durability as a high-pressure fuel pipe can be sufficiently ensured. In addition, since the discharge side hose 4 has flexibility, the discharge side hose 4 is connected to the fuel tank 1 and the vehicle body side. The relative displacement with respect to the fixedly supported high-pressure pipe 5 can be absorbed, and the pipe connection work can be facilitated. The return hose 8 that connects the curved low-pressure pipe 18 and the low-pressure pipe 7 may have relatively low pressure resistance. As shown in FIG. 3, here, solid rubber (EPDM) mixed with a conductive material is used.
Etc.) only. One end of this return hose 8 and the curved low-pressure pipe 18 and the other end of the return hose 8 and the low-pressure pipe 7 are respectively inserted and connected, and the outer periphery of the connection is, as shown in FIG. The metal fitting 25 is wound around, and both ends of the metal fitting are fastened and connected by bolts 26.

As shown in FIG. 1, the discharge hose 4 and the return hose 8 which are arranged side by side have flexibility, are both bent and deformed, and are both bent pipes on the fuel tank 1 side. The pipes 16 and 17 and the two pipes 5 and 7 on the vehicle body side are communicated with each other, and an intermediate portion between them is deformed so as to be directly joined to each other by a cable band 27 as a connecting means and is connected to each other in that state. The cable band 27 is a flexible resin molded band. As shown in FIG. 3, the belt 273 at the other end is inserted into a hole 272 provided in the engagement ring 271 at one end, and the belt 273 is inserted into the belt 273. The continuously formed locking projection 274 is connected to the variable claw 275 in the engagement ring 271.
, The discharge side hose 4 and the return hose 8 wound around the annular belt portion 273 can be directly joined to each other. The connection work of the discharge side hose 4 and the return hose 8 by such a cable band 27 can be performed very easily.

In this case, the skin tube portion 22 of the discharge side hose 4
Since both the return hose 8 and the return hose 8 are conductive, they are connected while maintaining conductivity. In addition, the return hose 8 is directly connected to the metal low-pressure pipe 7, and the low-pressure pipe 7 is connected to the vehicle body base and the engine 2 side. Have been. Therefore, by directly joining the skin tube portion 22 and the intermediate portion of the return hose 8, the entire skin tube portion 22 of the discharge side hose 4 can be kept electrically connected to the engine side. A vehicle (not shown) equipped with such an antistatic device of FIG. 1 travels for a long time in a state where the air is extremely dry. During this time, the fuel in the fuel tank 1 is sequentially supplied to the engine 2 by the fuel supply system A. I do.

At this time, the fuel in the fuel tank 1 passes through the fuel filter 15, is sucked into the fuel pump 3, is increased in pressure, and is supplied to the engine 2 through the discharge hose 4 and the high-pressure pipe 5. Then, when the fuel passes through the fuel filter 15 made of resin and the discharge side hose 4 which are the fuel path constituent members, the friction between the fuel and the main component hydrocarbon paraffin causes the separation of the electrons from the hydrocarbon molecules and the fuel. Is positively charged, and the fuel filter 15 and the discharge side hose 4 are negatively charged. The static electricity generated in the entire area of the discharge side hose 4 and the static electricity reaching the end of the discharge side hose 4 from the fuel filter 15 through the curved high pressure pipe 17 are transferred to the conductive skin tube section 22.
The return hose 8, the low-pressure pipe 7, the vehicle body base and the engine 2 are dispersed and erased, so that the charge amount of the discharge side hose 4 can be kept almost zero.

As described above, according to the antistatic device of FIG. 1, deterioration of the discharge portion of the discharge side hose 4 due to discharge of static electricity of the discharge side hose 4 directly to peripheral parts such as the rear floor can be reliably prevented. . Furthermore, static electricity generated in almost the entire area of the discharge side hose 4 can be eliminated by only an easy operation of connecting the discharge side hose 4 and the return hose 8 while maintaining conductivity, thereby reducing the assembly work cost. Since the tube portion 21 is a multilayer nylon tube and the skin tube portion 22 is formed of conductive solid rubber, the durability as a high-pressure fuel pipe can be sufficiently ensured, and since it has flexibility, The relative displacement between the fuel tank and the fixed fuel pipe supported on the vehicle body side can be absorbed, and also in this respect, the pipe connection work can be facilitated.

In the above, the discharge side hose 4 and the return hose 8 are connected to the cable band 27 as a connecting means.
Are connected directly to each other to maintain the conductivity. Alternatively, an antistatic device may be configured as shown in FIG. In this case, the discharge side hose 4 and the return hose 8 are arranged in parallel at a predetermined interval over the entire area, are sandwiched between a pair of upper and lower metal fittings 28 made of metal, and fastened to each other by bolts 29. It is configured as follows. Also in this case, the skin tube portion 22 of the discharge side hose 4 and the return hose 8 are connected while maintaining conductivity, and the same operation and effect as the antistatic device of FIG. 1 can be obtained. In particular, the discharge side hose 4 and the return hose 8 Are tightened by the connection fitting 28 and the bolt 29, so that a more reliable connection state can be maintained.

In the above description, the fuel tank 1 is made of resin. However, the fuel tank 1 may be made of sheet metal. Also in this case, static electricity in the entire area of the discharge side hose 4 is more reliably discharged to the vehicle body such as the engine 2. Is done. In the above description, the return hose 8 that connects the curved low-pressure pipe 18 and the low-pressure pipe 7 is formed of conductive solid rubber. However, in some cases, as shown in FIG. , The low pressure pipe 7 fixedly supported on the vehicle body side may be extended and provided, and the middle part of the discharge side hose 4 and the low pressure pipe 7 may be directly joined to each other by the cable band 27. The distal end of the low-pressure pipe 7 and the curved low-pressure pipe 17 are connected by a relatively short return hose 8 '. In this case, the same operation and effect as those of the antistatic device of FIG. 1 can be obtained.
In particular, the return hose 8 'may be insulating.

In the above description, the cable band 27 and the connecting fitting 28 have been described as connecting means. However, other connecting means capable of connecting the discharge side hose 4 and the return hose 8 while maintaining conductivity can also be used. Also in this case, FIG.
The same operation and effect as those of the antistatic device described above can be obtained. The antistatic device of FIG. 1 was installed in the fuel supply system of an automobile,
It may be provided in another fuel supply system connecting the fuel tank and the engine. In this case, the same operation and effect as those of the antistatic device of FIG. 1 can be obtained.

[0025]

As described above, according to the first aspect of the present invention, when the high-pressure fuel from the fuel tank is supplied to the engine side through the discharge side hose, all the static electricity generated in the entire pipe portion is conducted. From the skin tube portion to a conductive return pipe, and through this return pipe, to the engine side from a conductive fuel pipe supported on the vehicle body side, and the charge can be removed. For this reason, it is possible to prevent the discharge portion of the discharge side hose from deteriorating due to the discharge of the static electricity of the discharge side hose directly to peripheral components, thereby improving the durability. Furthermore, by simply connecting the discharge side hose and the return pipe with the connecting means while maintaining the conductivity, the static electricity generated in the entire pipe section can be completely eliminated, and there is no need to use a dedicated static elimination member. Cost and assembly work can be reduced.

[Brief description of the drawings]

FIG. 1 is a cutaway plan view of a main part of a fuel supply system of a vehicle equipped with an antistatic device to which the present invention is applied.

FIG. 2 is a schematic side sectional view of a main part cutaway of the fuel supply system of FIG.

FIG. 3 is a sectional view taken along line III-III of FIG. 1;

FIG. 4 is an enlarged sectional view of a resin socket used in the antistatic device of FIG.

FIG. 5 is a cutaway enlarged sectional view of an end of a return hose used in the antistatic device of FIG. 1;

FIG. 6 is a cutaway plan view of a main part of an antistatic device as another embodiment of the present invention.

FIG. 7 is a cutaway plan view of a main part of an antistatic device as another embodiment of the present invention.

[Description of Signs] 1 Fuel tank 2 Engine 4 Discharge side hose 7 Low pressure pipe (Return pipe) 8 Return hose (Return pipe) 21 Pipe section 22 Skin pipe section 27 Cable band 28 Connecting bracket A Fuel supply system

Claims (1)

[Claims] A discharge hose having a resin tube for supplying fuel from a fuel tank to the engine and a skin tube made of conductive resin or conductive rubber for covering the tube; An antistatic device comprising: a conductive return pipe for returning fuel returned from the fuel tank to the fuel tank; and a connecting means for connecting the skin pipe portion and the return pipe while maintaining conductivity.