JP4305853B2 - Fuel supply device - Google Patents

Description

  The present invention relates to a fuel supply device attached to a bottom wall of a fuel tank.

For example, in a fuel supply device attached to the bottom wall of a fuel tank such as a motorcycle, when a fuel pump is installed in the fuel tank, the bottom of the tank enters the fuel tank due to the breathing action of the fuel tank. Water or water generated by condensation in the fuel tank may accumulate.
Therefore, when a fuel pump using a brush motor is installed in the fuel tank, the position where the brush and the commutator are formed is higher in the fuel tank than the water staying at the bottom of the fuel tank. It is necessary to increase the height of the installed fuel pump. The brush motor rotates the rotor by controlling the current supplied to the rotor around which the coil is wound by the contact between the commutator and the brush, so that the commutator is configured when the brush and the commutator are immersed in water. This is because there is a risk of causing an electrical short circuit between the segments or between the commutator and the brush.

Thus, when the height of the fuel pump installed in the fuel tank becomes high, there arises a problem that the structure for installing the fuel pump in the fuel tank becomes complicated.
For example, in Patent Document 1, the fuel pump intake port faces the inside of the fuel tank, and the fuel pump is attached to the outer surface of the bottom of the fuel tank. In Patent Literature 1, this configuration prevents the commutator and the brush from being electrically short-circuited by being immersed in the water retained at the bottom of the fuel tank. Further, since the fuel pump is attached not to the inside of the fuel tank but to the outer surface of the bottom of the fuel tank, the structure for installing the fuel pump in the fuel tank is simplified.
Further, in Patent Document 1, it is disclosed that a brushless motor is used as a fuel pump drive unit. Therefore, even when water enters the fuel pump, an electrical short circuit of the motor unit can be prevented.

Japanese Patent Laid-Open No. 2003-120455

  However, as in Patent Document 1, when a fuel pump is attached to the outer surface of the bottom of the fuel tank, a seal structure that prevents the fuel from leaking out of the fuel pump from the pump chamber that pressurizes the fuel sucked from the suction port is required. It is. For example, in patent document 1, it is possible to seal between a pump chamber and the bearing of the rotating shaft which connects an impeller and a rotor. However, it is difficult to seal between the bearing sliding with the rotating shaft and the pump chamber, and Patent Document 1 does not disclose a structure for sealing between the pump chamber and the bearing.

Even if the space between the pump chamber and the bearing can be sealed, the sliding portion between the rotating shaft and the bearing is not lubricated by the fuel, so that there is a problem that sliding resistance increases and sliding wear increases.
The present invention has been made to solve the above problems, and in a fuel supply device in which a fuel pump is installed in a fuel tank and is attached to the bottom wall of the fuel tank, a structure in which the fuel pump is installed in the fuel tank is provided. An object is to simplify the sealing structure in the fuel pump, reduce sliding resistance and sliding wear in the fuel pump, and prevent electrical short circuit in the fuel pump.

In the first to third aspects of the invention, in the fuel supply device attached to the bottom wall of the fuel tank, the fuel pump is installed in the fuel tank, so that the seal structure in the fuel pump is simple. Further, since the inside of the fuel pump is filled with the fuel, the mechanical sliding portion in the fuel pump is lubricated with the fuel. Therefore, sliding resistance and sliding wear can be reduced.
According to the first aspect of the present invention, the suction filter extends outward from the lid member in the direction substantially the same as the direction in which the fuel pump is laterally placed in the fuel tank along the lid member. Therefore, the fuel pump and the suction filter can be installed in the fuel pump by rotating the fuel supply device while inserting the fuel pump and the suction filter from the opening of the fuel tank in the direction along the lid member. Therefore, the fuel pump and the suction filter can be connected to the fuel pump without expanding the opening of the fuel tank even if the filter area necessary for the suction filter is secured by extending the suction filter along the lid member to the outside of the lid member. Can be installed in a tank. Therefore, the strength of the fuel tank is improved. Further, since the terminal is at a height equal to or higher than the upper end portion of the fuel pump on the bottom side of the fuel tank, even if at least a part of the fuel pump is immersed in water, the terminal can be prevented from being immersed in water.

In addition, since the electric drive part of the fuel pump is a brushless motor, even if the fuel pump is installed horizontally along the lid member at the bottom of the fuel tank and the electric drive part is immersed in water, electrical short circuit is prevented it can.
Further, since the fuel pump is installed horizontally along the lid member at the bottom of the fuel tank, the height of the fuel pump in the fuel tank is reduced, and the lid member and the fuel pump are brought closer. Therefore, the fuel supply device becomes compact. Further, the structure in which the fuel pump is supported by the lid member and mounted in the fuel tank is simplified.

In addition , a terminal that is electrically connected to an electric device including a fuel pump installed in the fuel tank is installed away from the lid member above the fuel tank. According to this configuration, even if water stays at the bottom of the fuel tank, it is possible to prevent the terminal from being immersed in water if the terminal is installed above the fuel tank with respect to the remaining water. Therefore, an electrical short circuit between the terminals can be prevented.

  By the way, in the commutator-controlled motor, the motor efficiency is lowered due to the sliding resistance between the commutator and the brush and the fluid resistance received by the groove provided to divide the commutator into each segment. There is a problem that efficiency decreases. Here, the fuel pump efficiency is expressed by (motor efficiency) × (pump efficiency). The motor efficiency and pump efficiency are: I for the drive current supplied to the motor part of the fuel pump, V for the applied voltage, T for the torque of the motor part, N for the rotation speed of the motor part, and P for the fuel pressure discharged by the fuel pump. When the fuel discharge amount is Q, (motor efficiency) = (T × N) / (I × V), (pump efficiency) = (P × Q) / (T × N). Therefore, (fuel pump efficiency) = (motor efficiency) × (pump efficiency) = (P × Q) / (I × V).

Thus, when a fuel pump using a commutator control motor with a low efficiency of the fuel pump as a driving source is used for a fuel supply device of a two-wheeled vehicle, the battery capacity of the two-wheeled vehicle is small, so that the power supplied to the fuel pump is secured. Is difficult.
Also, since there is a risk of using deteriorated fuel or low-quality fuel containing alcohol, for example, in a two-wheeled vehicle, a commutator control motor is used in the fuel tank of a two-wheeled vehicle using such deteriorated fuel or low-quality fuel. When the fuel pump is mounted, electric corrosion or corrosion occurs at the sliding portion between the commutator and the brush, which may cause poor electrical conduction.

Therefore, in the invention described in claim 3 , the fuel pump using the brushless motor is installed in the fuel tank of the motorcycle. In contrast to the brush motor, the brushless motor has no sliding portion between the brush and the commutator, so the efficiency of the fuel pump is high. Therefore, even a battery having a small capacity of a two-wheeled vehicle can supply electric power necessary for the fuel pump. Moreover, even if deteriorated fuel or low-quality fuel is used, electrolytic corrosion or corrosion does not occur at the sliding portion between the brush and the commutator unlike the brush motor. Furthermore, since the sliding wear between the commutator and the brush does not occur, the life of the fuel pump is extended.

Embodiments of the present invention will be described below with reference to the drawings.
A fuel supply apparatus according to an embodiment of the present invention is shown in FIGS. 1 and 2. The fuel supply device 2 is attached to the bottom wall of the fuel tank 1 of the motorcycle.
The fuel supply device 2 includes a lid member 10, a fuel pump 20, a suction filter 70, a sender gauge 72, and the like. The lid member 10 is formed in a disk shape from polyacetal or polyphenylene sulfide (PPS) and closes the opening 1 a formed in the bottom wall of the fuel tank 1. The lid member 10 is integrally molded with a discharge pipe 11, a connector 12, a coupling portion 13, a fuel passage portion 14, an electric passage portion 16, and the like. The fuel pump 20 is installed horizontally on the bottom of the fuel tank 1 along the lid member 10.

  The discharge pipe 11 supplies the fuel discharged from the fuel pump 20 to the outside of the fuel tank 1. A suction filter 70 is snap-fitted and connected to the connecting portion 13. The fuel passage portion 14 and the electric passage portion 16 are provided so as to protrude above the fuel tank 1 from the lid member 10. The fuel passage portion 14 is connected to the discharge port 66 (see FIG. 3) of the fuel pump 20 through the fuel pipe 15, and guides the fuel discharged from the fuel pump 20 to the discharge pipe 11.

A terminal 17 is installed at the projecting side end of the electric passage portion 16. The terminal 17 is electrically connected to an electric device such as the fuel pump 20 and the sender gauge 72 via the lead wire 18, and is installed outside the fuel tank 1 of the lid member 10 via the electric passage portion 16. The connector 12 is electrically connected.
The terminal 17 is preferably installed above the fuel tank 1 above the lid member 10 and further above the fuel tank 1 above the end of the fuel pump 20 on the bottom side of the fuel tank 1. In the present embodiment, the terminal 17 is installed at substantially the same height as the end of the fuel pump 20 on the upper side of the fuel tank 1.

In the fuel pump 20, the discharge port 66 is coupled to the fuel passage portion 14 via the fuel pipe 15, and the suction filter 70 and the suction port 60 (see FIG. 3) that are coupled to the coupling portion 13 by snap-fit are coupled. By this, it is supported by the lid member 10 and mounted in the fuel tank 1.
The suction filter 70 extends to the outside of the lid member 10 along the lid member 10 in substantially the same direction as the direction in which the fuel pump 20 is horizontally placed. Thus, the suction filter 70 secures a filter area necessary for removing foreign matters in the fuel sucked by the fuel pump 20.

  The sender gauge 72 is connected to the float 74 by an arm 73, and outputs the position of the float 74 that rises and falls according to the fuel remaining amount in the fuel tank 1 as a fuel remaining amount signal. With the fuel supply device 2 attached to the fuel tank 1, the suction filter 70 and the arm 73 are substantially the same as the direction in which the fuel pump 20 is placed horizontally along the lid member 10 as shown in FIGS. 1 and 2. It extends to the outside of the lid member 10 along the same direction.

Next, the fuel pump 20 will be described in detail with reference to FIG.
The fuel pump 20 includes a motor unit 22 and a pump unit 23 that is driven by the rotation of the rotor 40 of the motor unit 22 and boosts the intake fuel.
The motor unit 22 as an electric drive unit is a so-called brushless motor, and includes a stator core 30, a coil 32, and a rotor 40. The stator core 30 is formed by laminating magnetic steel plates in the axial direction, and six teeth protruding toward the center side of the motor portion 22 are formed at equal intervals in the circumferential direction. A coil 32 is wound around each tooth. The resin housing 24 is molded with the stator core 30 and the coil 32. The metal housing 26 is insert-molded in the resin housing 24 and caulked with a suction side cover 50 described later. A plurality of through holes 26 a provided in the metal housing 26 is filled with the resin of the resin housing 24.

  The rotor 40 has a shaft 42, a rotary core 44, and a permanent magnet 46, and is rotatably installed on the inner periphery of the stator core 30. The shaft 42 which is a rotating shaft is supported at both ends in the axial direction by bearings 27. The permanent magnet 46 is formed as a single member in a cylindrical shape, and is installed on the outer peripheral side of the rotary core 44. The permanent magnet 46 forms eight magnetic pole portions 47 in the rotation direction. The eight magnetic pole portions 47 are magnetized so as to form different magnetic poles alternately in the rotational direction on the outer peripheral surface facing the stator core 30.

  The pump unit 23 is a so-called Wesco pump having a suction side cover 50, a discharge side cover 52, and an impeller 54. The suction side cover 50 and the discharge side cover 52 are case members that rotatably accommodate an impeller 54 that is a rotating member. The discharge side cover 52 is sandwiched between the resin housing 24 and the suction side cover 50 by the metal housing 26. The suction side cover 50 and the discharge side cover 52 form pump passages 62 and 64 on both sides in the axial direction of the impeller 54 along a blade groove of the impeller 54 described later. The fuel sucked into the pump passages 62 and 64 from the suction port 60 is pressurized by the rotation of the impeller 54. The fuel whose pressure is increased in the pump passages 62 and 64 is discharged from a fuel outlet (not shown) of the discharge side cover 52, passes between the stator core 30 and the rotor 40, and is discharged from the discharge port 66.

Next, the process of attaching the fuel supply device 2 to the fuel tank 1 is shown in FIG.
As shown in FIG. 4A, the fuel supply device 2 is inserted into the opening 1 a from the direction in which the fuel pump 20, the suction filter 70 and the arm 73 are along the lid member 10. Then, when the suction filter 70 and the arm 73 that extend greatly to the outside of the lid member 10 along the lid member 10 enter the fuel tank 1, as shown by an arrow X in FIG. Rotate 2 Then, as shown in FIG. 4B, the opening 1 a is closed with the lid member 10.

  According to the fuel supply device 2 of the present embodiment described above, the fuel pump 20 is installed in the fuel tank 1 and the fuel flows in the fuel pump 20, so that the seal structure in the fuel pump 20 is simple. Further, the sliding portion between the shaft 42 and the bearing 27 in the fuel pump 20 is lubricated with fuel, so that sliding resistance and sliding wear can be reduced.

Further, since the motor unit 22 of the fuel pump 20 is a brushless motor, the fuel pump 20 is installed horizontally along the lid member 10 at the bottom of the fuel tank 1, and the water stays at the bottom of the fuel tank 1. Even if the motor unit 22 is immersed in the motor unit 22, an electrical short circuit of the motor unit 22 can be prevented.
Further, since the fuel pump 20 is installed horizontally along the lid member 10 at the bottom of the fuel tank 1, the height of the fuel pump 20 in the fuel tank 1 is reduced, and the lid member 10 and the fuel pump 20 Can be brought closer. Therefore, the discharge port 66 of the fuel pump 20 is coupled to the fuel passage portion 14 via the fuel pipe 15, and the suction port of the fuel pump 20 is coupled to the suction filter 70 snap-fitted to the coupling portion 13. The fuel pump 20 can be supported and mounted in the fuel tank 1 with a simple structure.
Furthermore, since the fuel pump 20 is installed horizontally in the fuel tank 1 along the lid member 10, each component of the fuel supply device 2 including the fuel pump 20 installed in the fuel tank 1 and each device The height is lowered. Therefore, the whole fuel supply device 2 becomes compact.

  Further, the suction filter 70 and the arm 73 of the sender gauge 72 are installed so as to extend outside the lid member 10 in the same direction as the fuel pump 20 is laterally placed along the lid member 10. In the direction in which the fuel pump 20 along the fuel tank 20 is placed horizontally in the fuel tank 1, fuel is supplied while inserting the fuel pump 20, the suction filter 70, the arm 73 of the sender gauge 72 and the float 74 from the opening 1 a of the fuel tank 1. If the device 2 is rotated, other parts including the fuel pump 20 other than the lid member 10 can be installed in the fuel tank 1 even from the small opening 1a. By reducing the opening 1a, the strength of the fuel tank 1 is improved.

Further, the terminal 17 is located above the fuel tank 1 rather than the end of the fuel pump 20 on the bottom side of the fuel tank 1, and is installed at substantially the same height as the end of the fuel pump 20 on the upper side of the fuel tank 1. Therefore, even if the fuel pump 20 is almost immersed in water staying at the bottom in the fuel tank 1, the terminal 17 can be prevented from being immersed in water.
In addition, since a brushless motor having a higher fuel pump efficiency than the brush motor is used as the motor unit 22 of the fuel pump 20, even when the battery capacity is small as in a two-wheeled vehicle, the necessary power is supplied to the fuel pump 20. Can supply. In addition, the brushless motor does not have a sliding portion between the brush and the commutator unlike the brush motor, so even if deteriorated fuel or low quality fuel containing alcohol, for example, is used, the commutator and brush Since no electric corrosion or corrosion occurs at the sliding portion, it is possible to prevent electrical conduction failure. Further, since the sliding wear between the commutator and the brush does not occur, the life of the fuel pump 20 is extended.

(Other embodiments)
In the above embodiment, the fuel supply device is attached to the bottom wall of the fuel tank of the two-wheeled vehicle. However, in any fuel tank other than the two-wheeled vehicle, the fuel supply device is attached to the fuel tank. If the fuel pump is installed in the vehicle, it is desirable to adopt the configuration of the present invention.

  In the above embodiment, the coil 32 is wound around the outer stator core 30 and the permanent magnet 46 is installed on the inner rotor 40 to configure the brushless motor. However, the permanent magnet is installed on the outer rotor. The brushless motor may be configured by winding a coil around the inner peripheral stator core.

It is a side view which shows the fuel supply apparatus by one Embodiment of this invention. It is a perspective view which shows the fuel supply apparatus of this embodiment. It is sectional drawing which shows the fuel pump of this embodiment. It is explanatory drawing which shows the process of attaching the fuel supply apparatus of this embodiment to a fuel tank.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel tank, 1a opening part, 2 Fuel supply apparatus, 10 Cover member, 20 Fuel pump, 22 Motor part (electric drive part, brushless motor), 23 Pump part, 30 Stator core, 34 Coil, 40 Rotor, 46 Permanent magnet 54 Impeller (Rotating member)

Claims (3)

A fuel supply device attached to a bottom wall of a fuel tank and supplying fuel in the fuel tank to the outside of the fuel tank,
A lid member covering an opening formed in the bottom wall of the fuel tank;
A fuel pump supported by the lid member and installed at the bottom of the fuel tank;
A suction filter connected to the suction port of the fuel pump for removing foreign matter in the fuel sucked by the fuel pump;
An electrical passage formed in the lid member at the bottom of the fuel tank;
A terminal electrically connected to an electric device including the fuel pump installed in the fuel tank, separated from the lid member above the fuel tank, and installed in the electric passage;
With
The electric drive part of the fuel pump is a brushless motor, and the fuel pump is placed horizontally in the fuel tank along the lid member,
The terminal is at a height equal to or higher than the upper end of the fuel pump on the bottom side of the fuel tank,
The fuel supply device according to claim 1, wherein the suction filter extends outwardly of the lid member in a direction substantially the same as a direction in which the fuel pump is horizontally placed. The brushless motor is
A stator core, a coil wound around the stator core and controlled in energization to change the magnetic poles formed in the circumferential direction of the stator core, and magnetic poles alternately different in the rotation direction are formed on opposing surfaces facing the stator core. The fuel supply device according to claim 1, further comprising a rotor. The fuel supply device according to claim 1 or 2, wherein the fuel supply device is attached to a bottom wall of a fuel tank of a motorcycle.

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