JP2008157055A - Fuel feeding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel feeding apparatus with high reliability adapted to prevent a fuel temperature rise. <P>SOLUTION: A fuel feeding apparatus includes a suction port, a discharge port, and a housing having a motor room and a pump apparatus room. The motor room and the pump apparatus room are made to communicate with each other, but the suction port and the discharge port are made to directly communicate with only the pump room, fuel that has been suctioned from the suction port to the pump apparatus room is suctioned into the pump apparatus without passing through the motor room and discharged to the discharge port. A motor stator is embedded in a housing wall. The motor may be a brushless motor or a stepping motor, and can be RPM-controlled depending on the consumed flow rate of a fuel injection valve. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel supply device.

  The fuel supply system has been changed from a mechanical carburetor to an electronically controlled system having a fuel injection valve from the viewpoint of exhaust gas regulations and fuel efficiency improvement due to environmental problems, and all recent automobiles adopt the latter system. In recent years, environmental regulations have been expanded to include not only automobiles but also motorcycles, outboard motors, and other special vehicles. The fuel supply system used in automobiles is an in-vehicle system that uses a centrifugal pump installed in a fuel tank. Tank-type fuel supply devices (not shown) are the mainstream, but a relatively large fuel tank is required for this purpose, and the fuel tank has a small exhaust volume and mounting space, so in-tank fuel is supplied to the fuel tank. Vehicles that cannot be equipped with devices are difficult to deal with environmental problems, and an in-line fuel supply device that can be mounted outside the fuel tank is required.

  As a conventional fuel supply device, for example, as described in Patent Document 1, there is an in-line fuel supply device configured by a positive displacement pump and a DC brush motor excellent in self-priming property. The pump is composed of a suction valve, a discharge valve, a cylinder slidably fitted to the piston, a plate constituting a fuel pressurizing chamber together with the cylinder, a swash plate for moving the piston in the axial direction, and between the piston and the swash plate. It consists of a shoe that slides against the swash plate together with the piston, a spring that presses the piston against the swash plate, and a spring holder that serves as a seating surface of the spring. The motor is a permanent magnet, a yoke that fixes the permanent magnet, a magnetic circuit, a rotating shaft that is fixed integrally with the swash plate, a stator that is press-fitted and fixed to the shaft, has a winding, a brush that serves as an electrical contact, It consists of lead wires that connect the battery and brush. The pump and the motor are integrally connected to each other by the body or the housing, and the fuel is sucked from the suction port provided on the motor side of the housing, passes through the motor, enters the pump, and is pressurized and pressurized on the pump side of the housing Is supplied into the fuel passage from a discharge port provided in the fuel passage.

  In such a fuel supply device, when the motor is rotated by an external battery, the swash plate fixed to the shaft is rotated. Next, when the swash plate rotates, the piston pressed against the swash plate by the spring slides with the cylinder. When the piston moves downward, the volume of the fuel pressurization chamber composed of the piston, cylinder, intake valve, discharge valve, and plate increases, so that the pressure of the fuel pressurization chamber is reduced and is less than the opening pressure of the intake valve. At that time, fuel is sucked from the intake valve. Next, when the piston moves upward, the fuel pressurization chamber is pressurized, and the discharge valve is pressurized to a pressure equal to or higher than the internal pressure of the delivery pipe adjusted to a predetermined pressure by a pressure adjusting device installed outside. The fuel is discharged from. This operation is sequentially repeated with a plurality of pistons arranged concentrically in accordance with the rotation of the swash plate.

JP 2001-65447 A

  The axial piston pump is a highly efficient pump with excellent performance for sucking fuel under atmospheric pressure in the fuel tank (hereinafter referred to as self-priming performance), but the motor is located on the suction side of the pump due to the placement of the suction valve. Will be. For this reason, when the brush used as the electrical contact of the motor is worn, the wear powder may enter the pump and damage the pump. In addition, when the fuel temperature rises due to the heat generated by the motor, vapor is generated from the fuel, and when the vapor enters the pump, a vapor lock phenomenon occurs and the pump function is remarkably reduced.

  Further, for example, by arranging a seal member such as an oil seal or a mechanical seal at the connecting portion between the pump and the motor, it is possible to suppress intrusion of brush wear powder and an increase in fuel temperature. However, in this case, if the seal part is broken or deteriorated, there is a possibility that the fuel leaks to the outside, torque loss is generated at the seal part, and the structure becomes complicated and the motor becomes large.

  Accordingly, an object of the present invention is to provide a highly reliable fuel supply device that prevents an increase in fuel temperature.

  The fuel supply device of the present invention includes a housing having a suction port, a discharge port, an electric motor chamber and a pump device chamber, an electric motor provided in the electric motor chamber, and a pump device provided in the pump device chamber, In the fuel supply device in which the motor chamber and the pump device chamber communicate with each other, the fuel sucked into the pump device chamber from the suction port is sucked into the pump device without passing through the motor chamber, and is supplied to the discharge port. A fuel supply device that is discharged.

  The fuel supply device of the present invention includes a housing having a suction port, a discharge port, an electric motor chamber and a pump device chamber, an electric motor provided in the electric motor chamber, and a pump device provided in the pump device chamber. In the fuel supply apparatus in which the electric motor chamber and the pump device chamber are in communication with each other, both the suction port and the discharge port are in direct communication with the pump chamber.

  The fuel supply device of the present invention also includes a housing having a suction port, a discharge port, an electric motor chamber and a pump device chamber, an electric motor provided in the electric motor chamber, and a pump device provided in the pump device chamber, In the fuel supply device in which the electric motor chamber and the pump device chamber communicate with each other, the electric motor is a brushless motor.

  According to the fuel supply device of the present invention, it is possible to obtain an effect of preventing an increase in fuel temperature and increasing reliability.

Embodiment 1 FIG.
The fuel supply device of the present invention shown in FIG. 1 includes a generally hollow cylindrical housing 1, an electric motor 2 provided in the housing 1, and a pump device 3 provided in the housing 1 and driven by the electric motor 2. And has.

  The housing 1 has a cylindrical wall 4 and an end wall 5 which are housing walls, and has an electric motor housing 7 which forms an electric motor chamber 6 in which the electric motor 2 is accommodated, a cylindrical wall 8 and an end wall 9, and a pump device 3 therein. And a pump device housing 11 that forms a housed pump device chamber 10. The open end of the motor housing 7 is firmly connected to the open end of the pump device housing 11 by an appropriate means such as caulking, so that the motor chamber 6 and the pump device chamber 10 communicate with each other. The cylindrical wall 8 of the pump device housing 11 is provided with a fuel inlet 12, and the end wall 9 is provided with a fuel outlet 13. The motor housing 7 is closed except that the motor housing 7 communicates with the pump device housing 11 at the open end.

  The electric motor 2 includes a stator 14 embedded in the cylindrical wall 8 of the electric motor housing 7 and bearings 15 and 16 disposed at both ends of the cylindrical wall 4 so that the drive shaft 17 is rotatably supported. And a rotor 18 rotated by the rotating magnetic flux. In the illustrated example, the electric motor 2 includes a stator 14 having a core and a coil embedded in a synthetic resin cylindrical wall 4 together with a lead wire 19 to an external power source, and a rotor 18 is a permanent magnet on a drive shaft 17 or a core. Is a DC brushless motor fixed by adhesive or insert molding.

  The pump device 3 includes a cylinder block 20 provided in the pump device housing 11 and a plunger 22 that slides within a plurality of cylinders 21 provided in the cylinder block 20 to form a variable volume pump chamber in the cylinder 21. And. The cylinder block 20 further includes a suction passage 24 having a suction valve 23 for supplying fuel in the pump device chamber 10 into the cylinder 21 and a discharge valve 25 for discharging fuel compressed in the cylinder 21. A discharge passage 26 is provided.

  A compression spring 28 is provided at a protruding end of the plunger 22 from the cylinder 21 via a spring stopper 27, and the plunger 22 is always slid on a rotating swash plate 29 that is supported by the drive shaft 17 of the electric motor 2 and rotates together. The contact is possible.

  When the electric motor 2 rotates, the rotation of the rotary swash plate 29 causes the plunger 22 to reciprocate in order within the cylinder 21, sucking the fuel in the pump device chamber 10 and discharging it from the discharge port 13. At this time, the fuel that has entered the pump device chamber 10 from the suction port 12 is directly sucked by the pump device 3 without passing through the motor chamber 6 in which the motor 2 is disposed, so that the motor chamber 6 is placed in the fuel passage. I can't say there is.

  Thus, in this fuel supply device, there is no seal member that prevents the fuel from entering between the connecting portion of the pump and the motor, that is, between the electric motor chamber 6 and the pump device chamber 10. Further, both the suction port 12 and the discharge port 13 communicate directly with only the pump device chamber 10, and do not communicate directly with the motor chamber 6, but pass through the pump device chamber 10 and only through the bearing 16. The electric motor chamber 6 is a stagnation part of the fuel flow. Therefore, in the illustrated example, the electric motor 2 that is a DC brushless motor can be said to be disposed outside the fuel passage. Further, the electric motor 2 is a brushless motor, and there are no brushes in the fuel passage that cause foreign matter to enter the fuel or cause sparks.

  The fuel supply device of the present invention is provided in a housing 1 having a suction port 12, a discharge port 13, an electric motor chamber 6 and a pump device chamber 10, an electric motor 2 provided in the electric motor chamber 6, and a pump device chamber 10. The motor chamber 6 and the pump device chamber 10 are in communication with each other, and the suction port 12 and the discharge port 13 are both in direct communication with the pump device chamber 10. Further, the fuel sucked into the pump device chamber 10 from the suction port 12 is sucked into the pump device 3 without passing through the electric motor chamber 6 and discharged to the discharge port 13.

  Further, the electric motor 2 can be a brushless motor or a stepping motor, the electric motor 2 can be controlled in rotational speed according to the consumption flow rate of the fuel injection valve, or the brushless motor stator can be embedded in the housing wall of the housing. You can also.

  Therefore, according to the fuel supply device of the present invention, an increase in fuel temperature can be prevented and the reliability can be improved.

  In the illustrated fuel supply device, a DC brushless motor in which a rotor 18 of an electric motor 2 fixes a permanent magnet to a drive shaft 17 and a core, windings, and lead wires are embedded inside a cylindrical wall of a housing outside the fuel passage. Since it is used, it has excellent durability, can reduce loss torque, and can reduce the size of the motor. Further, since the housing of the DC brushless motor is a mold resin having a smaller heat transfer coefficient than that of metal, it is possible to suppress an increase in the fuel temperature by suppressing the amount of heat transferred to the pump side of the heat generated by the winding that becomes the heating element. It becomes possible.

  In addition, since the rotational speed of the DC brushless motor is determined by an excitation signal from a control controller (ECU), the rotational speed is easy to control, and the pressure is controlled by controlling the pump rotational speed in accordance with the flow rate of the fuel injection valve. It is also possible to minimize the return flow rate returned from the control device to the fuel tank, and to minimize sliding heat generated at the sliding portion between the piston and cylinder of the pump.

  Furthermore, as a method for fixing the permanent magnet of the rotor 18, an adhesive is conventionally used and the adhesive may be deteriorated by the fuel. However, a bonded magnet is also used for the permanent magnet, and the rotor 18 ( It becomes highly reliable by insert molding to the shaft.

Embodiment 2. FIG.
In the example shown in FIG. 1, the electric motor 2 of the fuel supply device has been described as a DC brushless motor. However, the DC brushless motor requires an expensive drive circuit for rotational control, and the control controller (ECU) becomes expensive. There was a problem. In the fuel supply apparatus shown in FIG. 2, this problem is solved by adopting a stepping motor as the electric motor 2 as shown in FIG. 2. The other structure is the same as that of the fuel supply apparatus of FIG.

  That is, the electric motor 2 that is a stepping motor includes a rotor 18 having a permanent magnet fixed to a drive shaft 17 and a stator 14 that is a coil that generates a drive magnetic field, as in the example of FIG. If such a stepping motor is used, the drive circuit of the control controller that rotates the electric motor 2 can be made inexpensive.

It is sectional drawing which shows the fuel supply apparatus of this invention. It is sectional drawing which shows another example of the fuel supply apparatus of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Housing, 2 Electric motor, 3 Pump apparatus, 4 Housing wall, 6 Motor room, 10 Pump apparatus room, 12 Inlet, 13 Outlet, 14 Stator.

Claims (7)

A housing having a suction port, a discharge port, a motor chamber and a pump device chamber;
An electric motor provided in the electric motor chamber;
A pump device provided in the pump device chamber,
In the fuel supply device in which the electric motor chamber and the pump device chamber communicate with each other,
The fuel sucked into the pump device chamber from the suction port is sucked into the pump device without passing through the motor chamber and discharged to the discharge port.   2. The fuel supply apparatus according to claim 1, wherein the electric motor is a brushless motor.   2. The fuel supply apparatus according to claim 1, wherein the electric motor is a stepping motor.   4. The fuel supply device according to claim 1, wherein the stator of the electric motor is insert-molded in a housing wall of the housing. 5.   5. The fuel supply device according to claim 1, wherein the number of revolutions of the electric motor is controlled according to a consumption flow rate of the fuel injection valve. A housing having a suction port, a discharge port, a motor chamber and a pump device chamber;
An electric motor provided in the electric motor chamber;
A pump device provided in the pump device chamber,
In the fuel supply device in which the electric motor chamber and the pump device chamber communicate with each other,
A fuel supply device, wherein both the suction port and the discharge port are in direct communication with the pump device chamber. A housing having a suction port, a discharge port, a motor chamber and a pump device chamber;
An electric motor provided in the electric motor chamber;
A pump device provided in the pump device chamber,
In the fuel supply device in which the electric motor chamber and the pump device chamber communicate with each other,
A fuel supply apparatus, wherein the electric motor is a brushless motor.

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