JP2011089501A - Fuel supply device - Google Patents

Abstract

An object of the present invention is to provide a highly reliable fuel supply device in which the lubricity of a bearing of a motor part is improved and the fuel pressure is stable.
In a fuel supply device that drives a pump unit 2B by rotation of a motor unit 2A and pressurizes and discharges fuel sucked by the pump unit 2B, the motor unit 2A includes a bracket 6, an iron core 7, and the iron core 7. A stator 9 composed of a coil 8 wound around, a rotor 10 that rotates around a shaft 11 facing the stator 9, a space between the stator 9 and the rotor 10, and a pump portion 2B that is filled with fuel. A bottomed cylindrical partition body 17 and a bearing 20 that is provided at the bottom of the partition body 17 and supports one end of the shaft 11 of the rotor 10. The rotor 10 has a plurality of fuels that penetrate the rotor 10 in parallel with the shaft 11. A passage 14 was provided.
[Selection] Figure 2

Description

  The present invention relates to a fuel supply device that supplies fuel to a fuel injection device of an internal combustion engine, for example.

  Regarding the fuel supply device, the fuel supply device disclosed in Patent Document 1 houses a stator and a control device in a bottomed case, and is provided with a plurality of recesses on the inner peripheral surface of a bearing disposed at the back of the case. Is a fuel passage.

  Moreover, although it is not a fuel supply device, for example, Patent Document 2 includes a partition body that separates a fluid from a stator, and a fluid supply passage for lubricating an anti-impeller side bearing disposed at the back of the partition body is a rotor. The structure of the electric water pump provided in the magnet is disclosed.

Japanese Patent No. 3402330 JP 2000-213490 A

  In the fuel supply device of Patent Document 1, the recesses that serve as the flow paths are formed at a plurality of locations in the axial direction on the sliding surface with the shaft on the inner surface of the bearing. Therefore, precise processing is required to ensure the accuracy of the bearing. This increases the processing cost and the accuracy management of the parts. In addition, since the sliding surface of the bearing and the shaft becomes discontinuous due to the dent, there is a problem that the rotor tends to vibrate or generate abnormal noise during rotation.

  Moreover, since the electric water pump of Patent Document 2 is provided with the fluid supply passage inclined at a predetermined angle with respect to the rotor axial direction, it is necessary to form an inclined hole in the magnet, resulting in an increase in processing cost. There was a problem.

  The present invention has been made to solve the above-described problems, and improves the lubrication performance of the bearing and increases the wear and temperature of the bearing without incurring an increase in cost for forming a fuel flow path for bearing lubrication. It is an object of the present invention to provide a fuel supply device that reduces the rise and improves the reliability of the bearing.

  The fuel supply device according to the present invention is a fuel supply device that drives the pump unit by rotation of the motor unit and pressurizes and discharges the fuel sucked by the pump unit. The motor unit is wound around the bracket, the core, and the core. A stator composed of a coil formed on the bottom, a rotor that rotates about a shaft opposite to the stator, a bottomed tubular partition wall that is separated from the stator and connected to the pump portion and is filled with fuel. A bearing is provided at the bottom of the partition body and supports one end of the shaft of the rotor, and the rotor is provided with a plurality of fuel passages penetrating the rotor in parallel with the shaft.

  According to the present invention, it is possible to prevent wear and overheating of the bearing of the motor of the fuel supply device without increasing the cost. In addition, since the sliding loss of the bearing can be reduced, not only the power consumption of the motor can be suppressed, but also the temperature rise of the fuel can be suppressed, so that the generation of vapor due to the vaporization of the fuel is reduced and the pump biting of the pump is avoided. The fuel pressure can be stabilized and the reliability of the fuel supply device can be improved. In addition, since sufficient lubrication is performed on the motor bearing, the motor rotation is not hindered even if the fuel supply device is inclined with respect to the horizontal direction. Therefore, the degree of freedom of the mounting posture of the fuel supply device increases.

1 is a general fuel system configuration diagram. It is sectional drawing which shows the fuel supply apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the rotor of the fuel supply apparatus which concerns on Embodiment 1, Comprising: (a) is a sectional side view, (b) is sectional drawing which looked at the cross section in the AA line of (a) in the arrow direction. (c) is the front view which looked at (a) from the arrow B direction. 6 is a graph showing the measurement results of bearing temperature according to the first embodiment. It is a figure which shows the rotor of the fuel supply apparatus which concerns on Embodiment 2 of this invention, Comprising: (a) is a top view which shows a part of rotor, (b) is a cross section in the DD line | wire of (a). It is the front view seen in the direction. It is a figure which shows the rotor of the fuel supply apparatus which concerns on Embodiment 3 of this invention, Comprising: (a) is a sectional side view, (b) is the cross section which looked at the cross section in the CC line of (a) in the arrow direction. FIG. 4C is a front view of FIG. It is a figure which shows the rotor of the fuel supply apparatus which concerns on Embodiment 4 of this invention, Comprising: (a) is a sectional side view, (b) is the cross section which looked at the cross section in the EE line of (a) in the arrow direction. FIG. 4C is a front view of FIG.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a fuel system in which the fuel supply apparatus of the present invention is used. The fuel supply device 2 is driven by a drive signal from the control unit 5, and the fuel supply device 2 sucks and discharges fuel from the fuel tank 1 through a filter. The discharged fuel is adjusted to a predetermined pressure by the pressure adjusting device 3, passes through the high-pressure fuel pipe, and is supplied to the fuel injection device 4. The fuel injection device 4 controls the injection timing and the injection amount based on the drive signal from the control unit 5 based on the engine speed, the load, and the like, and injects the fuel into the intake pipe.

  FIG. 2 is a cross-sectional view showing the structure of the fuel supply device 2. The fuel supply device 2 includes a motor part 2A and a pump part 2B. The motor unit 2 </ b> A includes a stator 9 including a stator core 7 disposed along the inner periphery of the bracket 6 and a plurality of stator coils 8 wound around the stator core 7. The stator 9 generates a rotating magnetic field when the excitation phase of the stator coil 8 is switched by a drive signal from the control unit 5.

  A rotor 10 is disposed inside the stator 9. The rotor 10 includes a shaft 11 and a magnet 12 that rotates about the shaft 11. FIG. 3 is a diagram showing details of the rotor 10. The magnet 12 is formed in a ring shape, and a plurality of poles are magnetized on the outer periphery. The magnet 12 is fixed to the shaft 11 via a nonmagnetic support 13 made of resin, for example, by insert resin shaping. A part of the outer peripheral surface of the shaft 11 is formed with a knurled or H-cut (not shown). By pouring a molding resin into this portion, the shaft 11 and the nonmagnetic support 13 are prevented from rotating by the anchor effect. Made.

  The nonmagnetic support 13 between the magnet 12 and the shaft 11 has a substantially bobbin shape, and supports the inner periphery and both end faces of the magnet 12. The nonmagnetic support 13 is provided with fuel passages 14 penetrating in parallel with the shaft 11, for example, at positions that divide the circumference of the rotor 10 concentrically with the circumference at equal intervals. The cross-sectional shape of the fuel passage 14 is not limited to a circle, and may be a long hole, an ellipse, or a half moon. On one side of the nonmagnetic support 13, that is, on the outer surface of the end on the pump portion 2 </ b> B side, a substantially fan-shaped guide groove 15 that communicates with the fuel passage 14 with the fuel passage 14 as a main position is directed toward the outer periphery of the rotor 10. Is formed. Further, a tapered inclined surface 16 that extends toward the outer periphery of the rotor is formed on the outer surface of the end portion where the guide groove 15 is provided. The plurality of fuel passages 14 and the guide grooves 15 are arranged at equal pitches on the circumference so as not to cause a vibration during rotation of the rotor.

  Between the stator 9 and the rotor 10, a bottomed cylindrical partition body 17 is disposed on the inner periphery of the stator core 7. A flange 18 is formed on one side of the partition body 17, and a seal member 19 is disposed on the outer periphery of the flange 18 to seal the fuel in the housing 23 and the partition body 17. The flange 18 is sandwiched between the motor unit 2A and a pump unit 2B described later, and fixes the partition wall 17 itself. The partition body 17 is made of a nonmagnetic material such as resin formed by molding. The rotor 10 is rotatably accommodated in the partition body 17.

  One end of the shaft 11 of the rotor 10 is supported by a first bearing 20 disposed at the bottom (back) of the partition wall body 17. The first bearing 20 may be inserted and molded when the partition body 17 is molded, or may be inserted after molding. The other end of the shaft 11 is supported by a second bearing 21 fixed to the flange 18 side of the partition wall body 17. The second bearing 21 is a slide bearing having a through hole in the figure, but may be a rolling bearing. The second bearing 21 is provided with an opening 22 for communicating the pump portion 2B and the rotor 10 side. The rotor 10 is arranged so that the end portion where the guide groove 15 is provided is on the second bearing 21 side.

  Next, the pump unit 2B will be described. The pump portion 2B includes a housing 23 that is airtightly coupled to the motor portion 2A via the flange 18 of the partition wall body 17. The housing 23 has a suction valve 24 connected to the fuel tank 1 and a discharge valve 25 connected to the fuel injection device 4. In the housing 23, a plate 26 fixed to the shaft end of the shaft 11 and rotating, a piston 27 and a cylinder 28 driven by the plate 26, a spring 29 for biasing the piston 27, and the like are provided.

  The plate 26 is fixed to the tip of the shaft 11 at a predetermined angle and is rotated by the rotation of the shaft 11. The head of the piston 27 is in contact with the inclined surface of the plate 26, and the piston 27 reciprocates in the cylinder 28 due to the rotation of the plate 26, and the fuel that flows into the housing 23 from the suction port 31 flows into the cylinder 28. Then, the pressure is increased by being fed into the pressure-increasing chamber 30 and is fed from the discharge port 32 through the discharge valve 25. The housing portion of the partition body 17 connected to the housing 23 and the opening 23 with the housing 23 is filled with fuel.

  During the operation of the fuel supply device 2 configured as described above, as the rotor 10 rotates, the fuel near the end face of the rotor 10 flows to the outer peripheral side by centrifugal force along the end face of the rotor 10, and the rotor 10 and the partition wall It is supplied to the first bearing 20 side at the back of the partition wall body 17 through the gap between the bodies 17. The fuel that has turned to the first bearing 20 side forms a fuel circulation flow that returns to the side surface of the rotor 10 again through the fuel passage 14 provided in the nonmagnetic support 13.

  At this time, the guide groove 15 starts from the position communicating with the fuel passage 14 and expands in a fan shape toward the outer periphery of the rotor 10, reaches the outer periphery of the rotor and faces the inner wall surface of the partition wall 17. Therefore, fuel tends to flow along the guide groove 15 toward the outer periphery of the rotor, lowering the pressure on the fuel passage 14 side, facilitating the flow of fuel into the fuel passage 14, and the fuel released from the guide groove 15 Since it flows into the inner part of the partition wall body 17 along the inner wall of the partition wall body 17, the fuel circulation efficiency can be improved. Furthermore, since the inclined surface 16 is provided at the end portion of the rotor 10, the fuel flowing along the inclined surface 16 is likely to flow into the gap between the rotor 10 and the partition body 17.

  As described above, the fuel is positively supplied to the first bearing 20 at the back of the partition body 17, so that lubrication and cooling are performed to suppress the temperature rise of the bearing 20 portion, and thereby the fuel Temperature rise is suppressed. As a result, reduction of bearing wear caused by insufficient lubrication and increase in sliding torque due to wear can be suppressed, and increase in power consumption of the motor can be suppressed. Furthermore, seizure of the bearing is prevented, and the reliability of the fuel supply device is improved.

  FIG. 4 is an actual measurement graph showing the bearing temperature according to the configuration of the present invention over time. The vertical axis represents the bearing temperature and the horizontal axis represents the elapsed time. In the figure, the chain line indicates that the rotor 10 is not provided with the fuel passage 14, and the solid line indicates the configuration of the present invention. It was confirmed that a temperature reduction effect of about 19 ° C. can be obtained by providing a fuel circulation path.

  As an effect of the circulating flow of fuel, heat accumulation inside the partition wall 17 due to heat generated by the motor can be suppressed, so that an increase in fuel temperature in the inner volume of the partition wall 17 is suppressed, and vapor is generated due to fuel vaporization. Is reduced. As a result, the vapor does not easily flow into the pump unit 2B, so that the so-called vapor biting of the fuel pump is suppressed, the fuel pressure is stabilized, and the performance of the fuel supply device is stabilized.

  In addition, according to the configuration of the present invention, the lack of lubrication to the bearing can be avoided even when the fuel supply device is mounted obliquely on the vehicle or when the vehicle is traveling uphill, so the degree of freedom in the mounting direction is increased. , Layout in a limited space becomes easy.

Embodiment 2. FIG.
The fuel supply device according to Embodiment 2 defines the positional relationship between the position of the fuel passage 1 provided in the rotor 10 and the plate 25 attached to the shaft 1, and other configurations are carried out. This is the same as Form 1.

  FIG. 5A is a plan view of the end portion of the rotor 10, and FIG. 5B is a front view of the cross section taken along line DD in FIG. As shown in FIG. 5, the configuration of the second embodiment is symmetric with respect to a line 35 connecting the top dead center 33 and the bottom dead center 34 of the plate 26 inclined to the shaft 11 and at an equal pitch. A fuel passage 14 and a guide groove 15 are disposed. With such an arrangement, the fuel passage 14 and the guide groove 15 are provided, so that there is an effect of preventing vibration during motor rotation.

Embodiment 3 FIG.
The fuel supply apparatus according to the third embodiment relates to the position where the fuel passage 14 is formed, and the other configurations are the same as those of the first embodiment.

  6A is a cross-sectional view of the rotor 10, FIG. 6B is a cross-sectional view of the cross section taken along the line CC of FIG. 6A in the direction of the arrow, and FIG. 6C is a front view of FIG. It is. As shown in FIG. 6, in the configuration of the third embodiment, the fuel passage 14 is formed on the inner peripheral surface of the ring-shaped magnet 12. The nonmagnetic support 13 has a pincushion shape as in the first embodiment, and a guide groove 15 communicating with the fuel passage 13 is formed on one end face thereof. The inclined surface 16 is also formed in the same manner as in the first embodiment.

  The rotor 10 is formed by inserting the magnet 12 and the shaft 11, which are the same technique as in the first embodiment, by insert formation when using the magnet 12 in which the recess that becomes the fuel passage 14 is provided in advance on the inner peripheral surface. In order to prevent the molding resin from flowing into the recess of the magnet 12 when forming, the molding die is provided with, for example, a pin-like shape, and the recess is thereby sealed, so that the fuel passage 14 is magnetized after molding. 12 and the resin that is the nonmagnetic support 13 are guaranteed to be formed at the boundary.

  According to the configuration of the third embodiment, since the concave fuel passage is formed on the inner peripheral surface of the magnet toward the shaft direction, the magnet can be manufactured by sintering or injection molding, and the types of applicable magnets are increased. be able to.

Embodiment 4 FIG.
The fuel supply device according to the fourth embodiment relates to the formation of the magnet of the rotor, and the other configurations are the same as those of the first embodiment.

  7A is a cross-sectional view of the rotor 10, FIG. 7B is a cross-sectional view of the cross section taken along line E-E of FIG. 7A in the arrow direction, and FIG. 7C is a front view of FIG. It is. As shown in FIG. 7, the configuration of the fourth embodiment uses an injection molding type plastic magnet 12a as a magnet. According to this, the plastic magnet 12a is directly formed on the shaft 11 by injection molding. The fuel passage 14 and the guide groove 15 similar to those of the first embodiment can be formed simultaneously with the molding of the plastic magnet 12a. The fuel passage 14 is formed with a predetermined distance (thickness) from the outer peripheral surface of the plastic magnet 12a so as not to affect the magnetic path in the plastic magnet 12a. A guide groove 15 communicating with the fuel passage 14 is formed on one end face of the rotor 10 formed of the plastic magnet 12a when the injection of the plastic magnet 12a is formed. The inclined surface 16 is also formed at the same time.

  According to the configuration of the fourth embodiment, the fuel passage hole can be formed simultaneously with the molding of the magnet, and the number of parts can be reduced, so that the cost can be reduced.

1 fuel tank, 2 fuel supply device,
2A motor part, 2B pump part,
3 pressure adjusting device, 4 fuel injection device,
5 Control unit, 6 Bracket,
7 Stator core, 8 Stator coil,
9 stator, 10 rotor,
11 shaft, 12 magnet,
12a plastic magnet, 13 non-magnetic support,
14 fuel passage, 15 guide groove,
16 inclined surface, 17 partition body,
18 flange, 19 seal member,
20 first bearing, 21 second bearing,
22 opening, 23 housing,
24 suction valve, 25 discharge valve,
26 plates, 27 pistons,
28 cylinders, 29 springs,
30 Booster chamber, 31 Suction port,
32 Discharge port.

Claims (11)

  In the fuel supply device that drives the pump unit by rotation of the motor unit and pressurizes and discharges the fuel sucked by the pump unit, the motor unit includes a stator including a bracket, a core, and a coil wound around the core, A rotor that rotates about a shaft facing the stator, a bottomed tubular partition wall that is spaced from the stator and the rotor and that is filled with fuel through the pump portion, and at the bottom of the partition body A fuel supply apparatus comprising: a bearing provided to support one end of a shaft of the rotor; and a plurality of fuel passages penetrating the rotor in parallel to the shaft.   2. The fuel supply device according to claim 1, wherein the rotor includes a magnet fixed to the shaft via a nonmagnetic support, and the fuel passage is formed in the nonmagnetic support. 3. .   The rotor is composed of a magnet fixed to the shaft via a nonmagnetic support, and the fuel passage is formed at a boundary between the magnet and the nonmagnetic support. The fuel supply device described in 1.   4. The fuel supply device according to claim 2, wherein the nonmagnetic support is made of resin, and the magnet is fixed to the shaft by insert resin molding.   The non-magnetic support is formed in a bobbin shape that holds the magnet, and a fuel guide groove leading to the fuel passage is formed on the end surface of the non-magnetic support on the pump portion side toward the outer peripheral side of the rotor. The fuel supply device according to claim 2, wherein the fuel supply device is provided.   The fuel supply device according to claim 5, wherein the guide groove has a fan shape with the fuel passage as a main position.   The fuel supply device according to claim 1, wherein the fuel passages are provided at an equal pitch on a concentric circle with the outer periphery of the rotor.   2. The fuel supply device according to claim 1, wherein a plate that drives a piston that controls fuel compression is attached to an end portion of the rotor shaft on the pump portion side so as to be inclined with respect to the shaft. .   The fuel supply device according to claim 8, wherein the fuel passage is disposed symmetrically with respect to a line connecting the top dead center and the bottom dead center of the inclined surface of the plate.   The fuel supply device according to claim 1, wherein the rotor is configured by a plastic magnet directly fixed to the shaft, and the fuel passage is formed in the plastic magnet.   2. The fuel supply device according to claim 1, wherein an inclined surface directed toward the bearing is provided on a circumferential portion of the end surface of the rotor on the pump portion side.

Images