JP4743175B2 - Vehicle fuel supply system - Google Patents

Description

  The present invention relates to a vehicle fuel supply device that supplies fuel stored in a fuel tank of a vehicle to the outside.

In the vehicle fuel supply device, in order to reduce the influence of switching noise generated from the pump control circuit disposed in the passenger compartment on the in-vehicle radio, the pump control circuit is connected to the fuel tank as in Patent Document 1. It has been carried out to be mounted on the upper part of the pump module for closing the opening. As a result, the load line from the pump control circuit, which is a noise source, can be shortened and out of the passenger compartment, and both noise filter (composed of coil and capacitor) inserted in the load line can be eliminated and noise can be reduced. Was made possible. In this case, although the switching noise is radiated from the fuel pump itself located in the fuel tank, the switching noise from the fuel pump does not become a problem because it is shielded by the metal fuel tank.
JP 2005-155602 A

  However, in recent years, since the fuel tank is being changed from metal to resin, in the resin fuel tank, radiation of switching noise from the fuel pump itself located in the fuel tank is generated by the resin fuel tank. In addition, it is reflected on the ground or directly radiated and picked up as noise by the radio antenna, causing a problem.

  To deal with such problems, the noise can be reduced by installing a noise filter in the load line in the pump control circuit as in the conventional case. However, the control circuit is increased in size (additional structural parts and heat radiation fins due to increased heat generation). ) And an increase in power loss, and mounting on the pump module is difficult.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide on-vehicle equipment in which electromagnetic noise from the fuel pump is reflected or directly radiated from the ground even if the fuel tank in which the fuel pump is disposed is made of resin. An object of the present invention is to provide a vehicular fuel supply device that can prevent the influence on the vehicle.

When a fuel pump located in a resin fuel tank is driven, electromagnetic noise from the fuel pump penetrates the fuel tank and is reflected on the ground or directly radiated, affecting on-vehicle equipment such as in-vehicle radio. Although there is a possibility, according to the inventions of claims 1 and 2 , electromagnetic noise from the fuel pump is blocked by a metal sub-tank connected to the vehicle body or a conductive sub-tank. Even if electromagnetic noise penetrating the fuel tank is reflected on the ground, it is possible to prevent in-vehicle equipment from being affected.

According to the invention of claim 3 , the electromagnetic noise from the fuel pump is a high-frequency noise when using a drive circuit that performs switching control such as PWM by voltage or current control of the fuel pump. Effective for suppression.

According to the invention of claim 4 , since the switching circuit constituting the fuel pump drive circuit is connected to the high side drive, the earth connection can be completed in the pump module in the fuel tank, and the earth terminal It can be implemented without special provision. In addition, since it can be connected by a short wiring as a common ground with the drive circuit, it can be prevented that the wiring becomes a new source of electromagnetic noise.

(One embodiment)
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a side view of a vehicle fuel supply device, and FIG. 2 is a plan view of the vehicle fuel supply device. 1 and 2, the vehicle fuel supply device 1 is installed in a fuel tank 2 of the vehicle (the tank surface of the fuel tank is indicated by a two-dot chain line in the figure) and stored in the fuel tank 2. Is supplied to an engine which is an external fuel consuming device. The vehicle fuel supply device 1 includes a lid member 3, a pump module 4, and a sub tank (corresponding to a shield means) 5. The lid member 3 has a resin flange 6 using POM (polyacetal) or the like, and the flange 6 closes the opening of the fuel tank 2.

Two shafts 7 are attached to the lower surface of the lid member 3 in the figure, and the sub-tank 5 is elastically moved in the vertical direction shown in FIG. It is suspended so that it can move.
With the configuration as described above, even if the fuel tank 2 to which the vehicle fuel supply device 1 is mounted expands or contracts due to a change in internal pressure or a change in the amount of fuel due to a temperature change, the bottom of the sub-tank 5 is It is possible to maintain a state where it is constantly pressed against the bottom inner wall.

  A pump module 4 is accommodated in the sub tank 5. The pump module 4 includes a fuel pump 8, a suction filter 9, a fuel filter 10, a pressure regulator 11, and the like. The suction filter 9 removes foreign matters contained in the fuel sucked from the sub tank 5 by the fuel pump 8. The fuel filter 10 accommodates the filter element 13 in the filter case 12 so as to cover the outside of the fuel pump 8 in the circumferential direction, and removes foreign matters contained in the fuel discharged from the fuel pump 8. A discharge pipe 14 is formed at the bottom of the filter case 12 to discharge the fuel from which foreign matter has been removed by the filter element 13, and the discharge pipe 14 is formed on the lower surface of the lid member 3 by a bellows pipe (not shown). Connected to the tube 15. A pressure regulator 11 that regulates the pressure of fuel discharged from the discharge pipe 14 is provided on the side of the bottom of the filter case 12, and the pressure of discharged fuel is adjusted by discharging excess fuel into the sub tank 5.

  A direct connector 16 is formed on the lower surface of the lid member 3, and the fuel pump 8 is electrically connected to the direct connector 16 via a lead wire 17. A discharge pipe 18, a sender connector 19 and a connector 20 are formed on the upper surface of the lid member 3. A fuel pipe is connected to the discharge pipe 18, and a liquid level gauge is connected to the sender connector 19 via a lead wire. A cable, power line, and GND line (all not shown) from the engine ECU are connected to 20.

  A storage chamber 21 is formed on the upper surface of the lid member 3, and a control circuit 22 (see FIG. 3) is stored in the storage chamber 21. The control circuit 22 is mainly composed of a control IC (Integrated Circuit) 23 (see FIG. 3) that houses a pump control circuit that controls electric power supplied to the fuel pump 8.

  Here, in this embodiment, the sub-tank 5 is made of metal (for example, stainless steel or iron), and a shield ground wiring 24 is welded (possible by soldering, caulking, or the like) to the end thereof. The shield ground wiring 24 is connected to the ground line of the control circuit 22 through the direct connection connector 16.

  FIG. 3 shows an electrical configuration of the vehicle fuel supply device 1. In FIG. 3, the control circuit 22 is mainly composed of a control IC 23. The input terminal of the control IC 23 is connected to the control terminal FPC and the diagnosis terminal DI of the control circuit 22. The control terminal FPC is a terminal to which a control signal for the control IC 23 is input from the engine ECU 25. The diagnosis terminal DI is a terminal for diagnosing the control IC 23 by the engine ECU 25.

The power supply terminal of the control IC 23 is connected to the power supply terminal + B of the control circuit 22, and is connected to the positive terminal of the battery 26 of the vehicle through the power supply terminal + B. The ground terminal of the control IC 23 is connected to the ground terminal E of the control circuit 22 and is grounded to the vehicle body through the ground terminal E. The output terminal of the control IC 23 is connected to the gate of a P-channel type power MOS (Metal Oxide Semiconductor) FET (Field Effect Transistor, corresponding to a switching circuit) 27. The source of the power MOSFET 27 is connected to the power supply terminal + B of the control circuit 22, the drain of the power MOSFET 27 is connected to the positive terminal FP + of the control circuit 22, and is connected to the positive terminal of the fuel pump 8 through the positive terminal FP +. That is, the power MOSFET 27 is connected so as to drive the fuel pump 8 on the high side. The negative terminal of the fuel pump 8 is connected to the negative terminal FP− of the control circuit 22 and is connected to the ground terminal E of the control circuit 22 through the negative terminal FP−. Between the positive terminal FP + and the ground terminal E of the control circuit 22, a diode 28 having the illustrated polarity is connected.
The control IC 23 adjusts the energization power to the fuel pump 8 and thus the rotational speed of the fuel pump 8 by switching control of the power MOSFET 27 such as PWM.

  The metal sub tank 5 is connected to the vehicle body by being connected to the negative terminal FP− of the control circuit 22 via the shield ground wiring 24. That is, the control circuit 22 adopts the drive circuit configuration of the high-side switch so that the shield ground wiring 24 can be shared with the negative terminal FP−, and the connector for connecting the shield ground wiring 24 is provided. It is devised so that it is not necessary to add terminals.

  By the way, since the power MOSFET 27 is switching-controlled by the control IC 23 as described above, high-frequency electromagnetic noise is radiated from the fuel pump 8. In this case, when the fuel tank 2 is made of metal, electromagnetic noise from the fuel pump 8 is blocked by the fuel tank 2, but there is no problem. When the industrial fuel supply device 1 is mounted, electromagnetic noise from the fuel pump 8 penetrates the fuel tank 2. Normally, since the fuel tank 2 is provided on the lower surface side of the floor panel of the vehicle, electromagnetic noise radiated upward from the fuel pump 8 through the fuel tank 2 is blocked by the floor panel. Electromagnetic noise radiated downward from the pump 8 through the fuel tank 2 is reflected on the ground or directly radiates between the ground and the floor, and then goes around the floor panel and is picked up as noise by the radio antenna. .

However, according to the vehicle fuel supply device 1 of the present embodiment, the subtank 5 surrounding the fuel pump 8 is made of metal and grounded to the vehicle body, so that electromagnetic noise radiated from the fuel pump 8 is obtained. Can be blocked by the sub tank 5.
Now, since the shielding effect by such a metal is obtained even if the bottom surface of the fuel tank 2 is shielded by metal, the inventor has the shielding effect by the metal sub tank 5 and the bottom surface of the resin fuel tank 2. The shielding effect by providing a metal was tested.

  FIG. 4 shows a case where the sub tank 5 is shielded with aluminum tape affixed (hereinafter referred to as a shield, which corresponds to the shield means of the present invention) 29, and its height dimension is h. FIG. 5 shows a case where the bottom surface of the fuel tank 2 is shielded with aluminum tape affixed (hereinafter referred to as a shield, which corresponds to the shield means of the present invention) 30 and its outer dimension is a × b. The shield 30 shown in FIGS. 4 and 5 is grounded to the vehicle body using wiring. However, when the shield 30 of the fuel tank 2 is actually grounded to the vehicle body, a metal frame attached to the tank or metal Connect to the band.

FIG. 6 shows the evaluation results of the electromagnetic noise reduction effect by the shields 29 and 30. In FIG. 6, noise is reduced when there is no shield (current state), when the height dimension of the shield 29 of the sub tank 5 is changed, when the dimension of the shield 30 on the bottom surface of the fuel tank 2 is changed, and when no shield ground connection is provided. Each effect was evaluated.
The determination values shown in FIG. 6 are not absolute values. When the sub tank 5 is shielded, the height of the shield 29 is set to h / 2, and when the bottom surface of the fuel tank 2 is shielded, the shield The dimension of 30 was set to 300 × 300 as a reference value.

  As a result of the noise evaluation, a shielding effect against electromagnetic noise from the fuel pump 8 can be obtained regardless of whether the sub tank 5 is shielded or the bottom surface of the fuel tank 2 is shielded as shown in FIG. It was confirmed. In this case, when the sub tank 5 is shielded, the shielding effect increases as the height dimension of the shield 29 increases. When the outer bottom surface of the resin fuel tank 2 is shielded, the shielding effect increases as the outer dimension of the shield 30 increases. Was confirmed to be large. Further, it was confirmed that when the shields 29 and 30 are not connected to the ground, the shielding effect cannot be obtained.

  From the above experimental results, it has been found that it is effective to provide a shield with a large size in either case of shielding the sub tank 5 or shielding the bottom surface of the fuel tank 2. Since connecting the shield to the vehicle body increases the manufacturing cost, it is possible to reduce the cost by connecting the shield to the sub-tank 5 surrounding the fuel pump 8 and connecting the shield to the vehicle body as in this embodiment. It is valid.

  According to such an embodiment, since the sub tank 5 surrounding the fuel pump 8 is made of metal and is grounded to the vehicle body, the electromagnetic noise radiated from the fuel pump 8 causes the resin fuel tank 2 to Even if it penetrates, the influence can be reduced without using a noise filter. Therefore, even if the electromagnetic noise radiated from the fuel pump 8 penetrates the resin fuel tank 2, the electromagnetic noise can be effectively reduced and prevented from being picked up as noise by the radio antenna.

Moreover, since the sub-tank 5 that is a component part of the pump module 4 can be implemented simply by changing the material to metal, the sub-tank 5 can be implemented without an increase in the number of parts, without incurring a significant increase in cost. Can be implemented.
Further, as a means for grounding the metal sub-tank 5 to the vehicle body, a direct connection connector 16 for connecting the fuel pump 8 is commonly connected by a short shield ground wiring 24. Therefore, the terminals of the direct connection connector 16 are connected to each other. This can be implemented without increasing the number, and an increase in cost can be suppressed in this respect as well, and the shield ground wiring 24 can be prevented from becoming a new source of electromagnetic noise.

  Furthermore, since the power MOSFET 27 as a switching circuit constituting the drive circuit of the fuel pump 8 is connected so as to be driven at the high side, the ground connection can be completed in the pump module 4 in the fuel tank 2, This can be done without providing a ground terminal.

( Reference example)
Next exemplary embodiment of the present invention will be described with reference to FIGS. 7 and 8, the embodiment and the same parts will not be described with the same reference numerals. This reference example is characterized in that a metal case covering the outer periphery of the fuel pump 8 is used as a shielding means.

  In FIG. 7, which shows a part of the vehicle fuel supply device in cross section, a connection ring 32 is press-fitted into the upper end of a metal case (corresponding to shield means) 31 that covers the outer periphery of the fuel pump 8. The metal case 31 of the fuel pump 8 is electrically grounded to the vehicle body by caulking the ground wiring 33 soldered (may be welded, caulked, etc.) to the ground terminal of the pump connector 34.

FIG. 8 shows an electric circuit diagram in the case of the configuration shown in FIG.
By the way, it is considered that the electromagnetic noise radiated from the fuel pump 8 is mainly radiated from the metal case 31 of the fuel pump 8 when switching the power MOSFET 27 constituting the drive circuit of the fuel pump 8 is controlled. As shown in FIG. 7, electromagnetic noise radiation can be effectively suppressed by connecting the metal case 31 covering the outer periphery of the fuel pump 8 to the vehicle body with a short ground wiring 33.

  According to such an embodiment, the metal case 31 covering the outer periphery of the fuel pump 8 is grounded to the vehicle body by the short ground wiring 33 so as to function as a shield means, so that a special means is used. In addition, electromagnetic noise from the fuel pump 8 can be effectively reduced, and the ground wiring 33 can be prevented from becoming a new source of electromagnetic noise.

In this reference example, if the metal case 31 covering the outer periphery of the fuel pump 8 and the ground terminal of the pump connector 34 are connected, there is an effect of suppressing electromagnetic noise. Contact connection with the ground terminal in the fuel pump 8 or elastic contact with a spring may be used.

The present invention is not limited to the above embodiment, but can be modified or expanded as follows.
The shield structure, the sub-tank and Ri metallic filler is molded by mixing electrically conductive resin, the shield metal may be used as the resin molded article is insert.

The shield of the sub tank 5 and the shield of the fuel tank 2 may be combined.
As a ground connection method to the vehicle body, it may be taken out onto the flange 6 through the metal shaft 7.

The side view which shows a part of vehicle fuel supply apparatus in one Example of this invention in a cross section Plan view of vehicle fuel supply system Schematic showing the electrical configuration of the vehicle fuel supply device Figure showing the sub tank shield of the noise evaluation test Diagram showing fuel tank shield for noise evaluation test Diagram showing noise evaluation test results FIG. 1 equivalent view showing a reference example of the present invention 3 equivalent figure

Explanation of symbols

  In the drawings, 1 is a vehicle fuel supply device, 2 is a fuel tank, 4 is a pump module, 5 is a sub tank (shield means), 8 is a fuel pump, 24 is a shield ground wiring, 27 is a power MOSFET (switching circuit), 31 Is a metal case (shielding means), 32 is a connection ring, and 33 is a ground wiring.

Claims (4)

A fuel supply device for a vehicle having a fuel pump disposed in a fuel tank of a vehicle and supplying the fuel stored in the fuel tank to the outside in a driving state of the fuel pump;
A metal sub-tank that is provided so as to surround the fuel pump so as to include the lower part of the fuel pump and that shields electromagnetic noise radiated at least downward from the fuel pump in a state of being grounded to the vehicle body. A fuel supply device for a vehicle, comprising: A fuel supply device for a vehicle having a fuel pump disposed in a fuel tank of a vehicle and supplying the fuel stored in the fuel tank to the outside in a driving state of the fuel pump;
A sub-tank that is provided so as to surround the fuel pump so as to include the lower part of the fuel pump, and has conductivity to block electromagnetic noise radiated at least downward from the fuel pump in a state where the fuel pump is grounded. A vehicle fuel supply device comprising: 3. The vehicle fuel supply device according to claim 1, wherein the sub-tank blocks switching noise generated when the fuel pump is subjected to switching control as electromagnetic noise . 4. The fuel pump drive circuit is configured to have a switching circuit,
4. The vehicle fuel supply device according to claim 1, wherein the switching circuit is connected so as to drive the fuel pump at a high side .

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