GB2378222A

GB2378222A - In-tank fuel supply apparatus

Info

Publication number: GB2378222A
Application number: GB0207988A
Authority: GB
Inventors: Michio Onuma
Original assignee: Keihin Corp
Current assignee: Keihin Corp
Priority date: 2001-04-09
Filing date: 2002-04-08
Publication date: 2003-02-05
Anticipated expiration: 2022-04-08
Also published as: JP2002303217A; HK1049871B; TW550338B; HK1049871A1; GB0207988D0; GB2378222B

Abstract

A fuel supply apparatus for mounting in an opening of a fuel tank comprises a lid 20, a fuel pump E, a filter 21 and a pump driving circuit 23. The lid 20 closes an opening in a fuel tank T, and includes a supporting portion 20D, to support the fuel pump E, and a recess portion 20E to receive the filter 21. The pump E and filter 21 are attached to the lid 20 such that they are located within the tank T. The pump driving circuit 23 is attached to the lid 20 such tat it is located outside the tank T. The pump driving circuit 23 may also be positioned such that it is not in contact with a discharge passage 22 formed in the lid 20. The lid 20 may be made from a synthetic resin material. A pump driving circuit receiving member 24 may be made from a metallic material and may be used to attach the lid 20 to the tank T.

Description

SPECIFICATION

TITLE OF THE INVENTION_

FUEL SUPPLY APPARATUS

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

The present invention relates to a fuel supply apparatus in which a fuel pump provided with a pump portion and a motor for driving the pump portion is received and arranged within a fuel tank, a pressure of a fuel within the fueltank is increased by the fuel pump, and the fuel having the increased pressure is supplied toward an engine, and this is employed as a fuel supply apparatus in a fuel injection apparatus.

DESCRIPTION OF THE CONVENTIONAL ART

In the conventional fuel pump mentioned above, thereis executed a process ofoontrollinga rotational number of the motor by a pump driving circuit so as to change a discharge amount of fuel discharged from the fuel pump. A first prior example of the fuel pump provided with the pump driving circuit is shown in Japanese Unexamined Patent Publication No. 7-259676.

In accordance with this structure, a pump portion serving for a pump operation and a motor for driving the pump portion are arranged within a housing constituting the fuelpump,anda circuit ease receiving a motor control circuitis arranged withinthehousing.

s In accordance with this structure, when an electric current is applied to the motor and the pump portion is driven, the fuel discharging from the pump portion flowsdown toward a discharge passage within the housing, thereby radiating heaLgeneratedin the controlcircuit by the fuel flowing within the housing into the fuel via the circuit case. A second prior example is disclosed in Japanese Unexamined Patent Publication No. 6280707. This is structured such that a pump portion end a motor portion for driving thepump portion are arranged within a motor housing, and a fuel is discharged from an inner portion of the housing toward a fuelpassage due to en operation of the pump portion.

Further, a controller case receiving a drive control circuit for controlling the drive operation of the motor portion is mounted to en outer wall of the fuel passage in the downstream side of the pump portion. In accordance with this structure, when the fuel pump is driven,the controller caseis cooled by the fuelflowing through the fuel passage. Further, at this time, no fuel intrudes into the controller case.

The first example of the conventional fuelsupply apparatus mentioned above has the following problems.

Since the circuit case in which the control circuit is received is installed within the fuel pump, the fuel having the increased pressure and flowing within the

housingis applied Lo the circuit case, so that a secure sealing property of the circuit case is required.

Accordingly, in order to secure the sealing property, a specific sealmemberis required, end a manufacturing operation thereof becomes complex, whereby en increase of manufacturing cost is generated. Further, since itis preferable that the fuelflowing within the housing flows toward the discharge passage with a smooth flow, it is necessary to carefully select an arrangement of the circuit ease so that the circuit ease arranged within the housing does not prevent the flow, so that a limitationis given to a freedom of arranging the circuit case. Further, since the circuit case is cooled only by the fuel moving from the fuel pump toward the discharge passage,there is a risk that the fuel moving from the discharge passage toward the fuel injection valve is heated, so that there is a risk that bubbles are generated within the fuel pipe and it is not preferablein view of afuelsupply properly. Further, since the circuit easels arranged within the housing, a size of the fuel pump itself is apt to be increased, end particularlyln an in-tank type fuel pump in which the fuel pump is arranged within the fuel tank, it is necessary to take a support of the fuel pump into consideration. Further, in accordance with the second prior

example, since the controller case is mounted to the outer wall of the fuel passage, it is hard to sufficiently secure a contact area between the controller case and the fuel passage, so that it is impossible to sufficiently cool the controller case.

SUMMARY OF THE INVENTION

The present invention is made by taking the problems mentioned above into consideration, and an object of the present invention is to provide a fuel supply apparatus which can effectively cool a pump driving circuit driving a fuel pump, does not largely increase a temperature of fueldischargedirom the fuel pump, can arrange a size of the fuel pump in compact, and can achieve a reduction of manufacturing cost.

In order to achieve the object mentioned above, in accordance with a first aspect of the present invention, there is provided a fuel supply apparatus comprising: an opening portion disposed below a fuel tank; and a fuel pump supported by a lid member closing the opening portion, wherein a supporting portion supporting the fuel pump and a strainer receiving recess portion receiving a strainer connected to a pump suction passage of the fuel pump are formed in an fuel tank inner side of the

lid member, a discharge passage supplying a fuel discharged from the fuel pump toward an engine is arranged in the lid member through the lid member so as to be open toward an external portion, and a pump driving circuit driving the fuel pump is arranged in an fuel tank outer side of the lid member at a position opposing to the strainer receiving recess portion.

Further, in accordance with a second aspect of the present invention, there is provided a fuel supply apparatus as recited in the first aspect, wherein the pump driving circuit is arranged et a position et which the pump driving circuit is not in contact with the discharge passage formed in the lid member.

Further, in accordance with a third aspect of the present invention, there is provided a fuel supply apparatus as recited in the first aspect, wherein the lid member is formed with a synthetic resin material, a driving circuit receiving member receiving the pump driving circuit is formed with a metal material, and thelidmemberis mounted Lo the fueltank vie the driving circuit receiving member.

Since one side of the pump driving circuit is indirectly cooled by the fuel within the pump receiving recess portion of the lid member and another side of the pump driving circuit is cooled by the atmospheric air via the driving circuit receiving member, it is

possible to affectively coolthe pump driving circuit.

Further, since the pump driving circuit is not received within the fuel pump, the size of the fuel pump is not increased, and the fuel discharged from the discharge passage is not largely heated.

Further, in accordance with the second aspect of the present invention, since the pump driving circuit is not directlyin contact with the discharge passage, the temperatureincrease discharged from the discharge passage is restricted, and it is possible to reduce the generation of bubbles within the fuel pipe.

Further, in accordance with the third aspect of the present invention, since the lid member is mounted to the fueltankvia the driving circuit receivingmember made of the metal material, it is possible to securely mount the lid member to the fuel tank even in the case that the lid member is formed with the synthetic resin material, and further it is possible to improve a heat radiation property of the pump driving circuit to the atmospheric air side.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a vertical cross sectional view showing an embodiment ofa fuel supply apparatus in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A description will be given below of a first

embodiment of a fuel supply apparatus in accordance with the present invention with reference to Fig. 1.

Reference symbol K denotes a pump case formed in a cylindricalshape, inwhichanotherendK2isopenupward via an upper engaging step portion Kl, and one end K4 is open downward via a lower engaging step portion K3.

Reference numeral 1 denotes a pump housing arranged on the lower engaging step portion K3 of the pump case K so as to be brought into contact therewith. A pump cover2is arranged onalower surface of the pump housing l so as to be brought into contact therewith. In this state, a lower end of one end K4 in the pump case K is inward caulked toward the pump cover 2, whereby the pump housing 1 and the pump cover 2 are arranged on the lower engaging step portion K3 so as to be firmly fixed thereto. Reference numeral 3 denotes a bearing holding cover arranged on the upper engaging step portion K1 of the pump case K so as to be brought into contact therewith. In this state, an upper end of another end K5 of the pump case K is inward caulked toward the bearing holding covers, whereby the bearing holding cover 3 is arranged on the upper engaging step portion K1 so as to be firmly fixed thereto. Further, a pump chamber 4 is formed in the contact surfaces between the pump housing 1 and the pump cover 2, and a downstream side of a pump suction passage 5 pierced

in the pump cover 2 and an upstream side of a pump discharge passage 6 pierced in the pump housing 1 are open within the pump chamber 4. Accordingly, a motor chamber 8 is formed by the inner portion K5 of the pump case K, an upper surface 1A of the pump housing 1 and a lower surface 3A of the bearing holding cover 3, and a downstream side of the pump discharge passage 6 and an upstream side of a discharge passage 7 provided in the pump housing 1 and the pump cover 2 are open to the motor chamber 8.

AmotorMisconstitutedoftheroilowingelements. Reference numeral 10 denotes a rotor yoke formed in a closed-end cylindrical shape. A magnet 11 is arranged in an inner peripheral wall of the rotor yoke 10 so as to be fixed thereto by an adhesive agent or thelike, andisfirmlyfixedtoarotaryshaft12passing through a center of the rotor yoke 10 in an integral manner. Further, en upper portion of the rosary shaft 12 isrotatably supported to a tube portion3B extending downward from a center of the bearing holding cover 3 via a bearing B. and a lower portion of the rotary shaft 12 is rotatably supported to the pump housing lvisa bearing C. Referencenumeral13 denotes astator around which an armature coil 14 is wound. The stator 13 is arranged in an inner side of the rotor yoke 10 and arranged in an outer side of the tube portion 3B

so as to be fixed thereto. The motor M formed in the manner mentioned aboveis received and arranged within the motor chamber 8.

A pump P is structured such that an impeller 15 is arranged so es to tee received within the pump chamber 4, and a lower end of the rotary shaft 12 is engaged with the impeller 15.

Inaccordanco with the structure mentioned above, one end K4 of the pump case K is closed by the pump housing 1 and the pump cover 2, the pump portion P is arranged so that the impeller 15 is received within the pump chamber 4 between the pump housing 1 and the pump cover 2. On the other hand, another end K2 of the pump case K is closed by the bearing holding cover 3, and the motor is arranged so as to be received within the motor chambers formed by the bearing holding cover 3, the pump case K and the pump housing 1.

Further,afilterFforremovingforeignmaterials contained in the fuel flowing from the inner portion of the motor chamber 8 toward the discharge passage 7 is arranged so as to be received within the motor chamber 8. The filter F is structured such that a cylindrical tube portion FD (the tube portion ED is formed by a net or the like having a filtering performance) is formed upward from a bottom portion FA, a fitting tube portion FB is formed in an upper

end thereof, and a pump discharge passage FC connected to the pump discharge passage 6 of the pump housing 1 is formed through the bottom portion FA. The filter F mentioned above is arranged within the motor chamber 8, in particular, the bottom portion FA of the filter Fis arranged on the upper surfacelAof the pump housing 1, the tube portion FD is arranged so as to surround an outer periphery of the rotor yoke 10 in the motor M, and the fitting tube portion FB is arranged so as to be fitted to the upper portion of the inner portion K5Ofthepump case K. In accordance with the structure mentioned above, a filtration chamber A is formed between the tube portion FD of the filter F and the inner portion K5 of the pump case K, an upstream side ofthedischargepassageisconnectedLoaninnerportion of the filtration chamber A so as to be open, and a downstream side thereof is open toward an external portion. In accordance with the fuel pump E structured as mentioned above, when the motor M rotates and the pump portion P serves a pump operation, the fuel having the pressureincreasedwithin the pump chamber4is supplied to an inner side of the filter F via the pump discharge passages 6 and FC, and the fuel within the inner side is discharged to the filtration chamber A formed by the outer portion of the filter F and the inner portion

K5 of the pump case K after the foreign materials are removed by the tube portion FD of the filter F. The cleanly filtered fuel within the filtration chamber A is supplied, forexample, toe fuel distribution pipe to which a fuel injection valve is mounted, in an externalportion from the discharge passage7. In this case, the fuel pump E mentioned above is structured such as to employ an outer rotor type brushless motor, however, it may be a DC motor, and is not limited to this motor. Further, the structure of the filter is not limited to the present embodiment.

Reference symbol T is a fuel tank of which the fuel is storedinaninner portion. An opening portion TA is pierced in a lower bottom portion. Reference numeral 20 denotes a lid member closing the opening portion TA of the fuel tank T and supporting the fuel pump E. The lid member 20 is provided with a cylinder portion 20A arranged so es tobeinsertedto the opening portion TA, and a flange portion 20B extending out from the below of the cylinder portion 20A toward an outer peripheral direction. Further, a supporting portion 20D and a strainer receiving recess portion 20E are formed in a fuel tank inner side 20C (in other words, on an upper surface of the cylinder portion 20A) facing to the inner portion of the fueltank fin thelid member 20. The supporting portion 20D is formed so as to 1 1

protrude out upward from an outer peripheral portion of the fuel tank inner side 20C of the lid member 20, and is formed in a shape which can be directly or indirectly brought into contact with an outer surface in a longitudinal direction of the pump case K in the fuel pump E. Further, the strainer receiving recess portion 20E is recessed in a lower direction from the fuel tank inner side 20C of the lid member 20 toward an inner portion of the cylinder portion 20A, and can receive a strainer 21 attached to the pump suction passage 5 of the fuel pump E. Fu- ^ ler, a discharge passage 22 in which one end is open within the fuel tank T end another endis open toward en externalportion is pierced in the lid member 20. Reference numeral 23denotesapumpdrivingcircuit,forexample, acontrol circuit of a brushless motor, a control circuit of a DC motor or the like. The pump driving circuit 23 is arranged so as to be received in a driving circuit receiving member 24.

Further, the fuel pump E is arranged so as to be received within the fueltank fin the following manner.

Firstly, the fuel pump E is arranged so as to face to the fuel tank inner side 20C, and an outer side of the pump oaseKinthefuelpumpEismountedto the supporting member20D. Thisis achieved, for example, by winding a forkshaped band 25 arranged in a groove portion 20F

provided in the middle of the supporting portion 20D around the pump case K so as to engage therewith. In accordance with the manner mentioned above, the fuel pump E is mounted to the lid member 20, and at this time, thestrainer21mountedtothepumpsuctionpassage 5 open tothelower portion of the fuelpumpEis arranged soastobereceivedwithinthestrainerreceivingrecess portion 20E of the lid member 20. Further, the discharge passage7Of the fuel pump E open to thelower portion is arranged so as to be connected to the discharge passage 22 of the lid member 20. Next, the driving circuit receiving member 24 arranging so as toreceivethepumpdrivingcircuit23isarrangedLoward a fuel tank outer side 20G of the lid member 20, and at this time, the pump driving circuit 23 is arranged so as to face to the strainer receiving recess portion 20E. Being arranged so as to face to the strainer receiving recess portion 20E means that one half or moreareaofasubstrate23A,onwhichpartsconstituting thepumpUrivingcircuit23,forexample,anovervoltage protection circuit, a constant voltage circuit, a position detecting sensor, a power transistor and the like are arranged, is arranged so as to face to the strainer receiving recess portion 20E. Further, at this time,a first flange portion 24A extending outward from a part of the driving circuit receiving member

24 is arranged on the flange portion 20B of the lid member 20 so as to be brought into contact therewith.

In this case, a signal output from the pump driving circuit 23 is input to the armature coil 14 of the fuel pump E via a feeder element Q. Further, the fuel pump E is mounted to the supportingportion20Dofthelidmember20,thecylinder portion 20A of the lid member 20, on which the driving circuit receiving member 24 with the pump driving circuit 23 being arranged and received therein so as to race to the fuel tank outer side20G ofthelid member 20 is arranged in a contact manner is arranged so as to be inserted within the opening portion TA of the fuel tank T. the flange portion 20B of the lid member 20 is arranged on a supporting portion TB integrally formed with the fuel tank T so as to be brought into contact "herewith, and in such a state, a secondilange portion24B extendingoutwarUfromanotherportion(the left side in the drawing) of the driving circuit receiving member 24 is engaged toward a supporting portion TD via a bolt 26.

In accordance with the structure mentioned above, the lid member 20 is held by the fuel tank T via the driving circuit receiving member 24 so as to be fixed and arranged, and at this time, sealing between the opening portion TA of the fuel tank T and the cylinder

portion 20A of the lid member 20 is made by an O-rig Accordingly, when the fuel pump E is driven on the basis of an output signal from the pump driving circuit 23, the fuel stored within the fuel tank T is sucked within the pump chamber 4 via the strainer 21 and the pump suction passage 5, and the fuel having the pressure increased within the pump chamber 4 is supplied into the motor chambers vie the pump discharge passages 6 and FC. Further, the fuel within the motor chamber 8 is supplied into the filtration chamber after the foreign materials are removed by the filter F. and this clean fuel is supplied toward the external portion via the discharge passage 7 and the discharge passage 22 of the lid member 20 Further, in accordance with the fuel supply apparatus of the present invention, the following features are provided. Firstly, the pump driving circuit 23 is arranged in the fuel tank outer side 20G of the lid member 20 at a position opposing to the strainer receiving recess portion 20E. In accordance with this structure, since the pump driving circuit 23 isarrangedintheatmosphericairandisnotimmersed into the fuel, it is not necessary to prepare a specific seal member for the seal thereof and it is unnecessary to assemble the seal member, so that it is possible

to achieve a stability of an output performance and a reduction of manufacturing cost. Further, in accordance with the structuresin which the pump driving circuit 23 is not arranged within the fuel pump E and the pump driving circuit 23 is not arranged so as to be directly in contact with the discharge passages 7 and 22, since the fuel flowing clown toward the external portion such as the fuel injection valve or the like is not directly heated by the heat radiated from the pump driving circuit 23, it is possible to restrict increase of the fuel temperature, i, is possible JO restrict generation of the bubbles within the fuel pipe system, and it is possible to achieve an improved fuel supply. Further, in accordance with the structure in which the pump driving circuit23is not received within the fuel pump E, it is possible to reduce a weight of the fuel pump E itself and it is possible to arrange it compactly, in particular, at a time of mounting the fuel pump E to the supporting portion COD, it is not necessary to peculiarly increase a rigidity of the supporting portion 20D and it is possible to largely improve a mounting property. Further, in accordance with the structure in which the pump driving circuit 23 is arranged in the fuel tank outer side 20G at a position opposing to the strainer receiving recess portion 20E, it is possible to secure a large cooling

area with respect to the pump driving circuit 23, it is possible to cool the pump driving circuit 23 by the fuel within the strainer receiving recess portion 20E in which the strainer 21 sucks the fuel to generate the fuel stream always, and it is possible to radiate heat into the atmospheric air via the driving circuit receivingmember24, sothatitis possible to increase the cooling effect with respect to the pump driving circuit23. Further, in accordance with the structure in which the lid member 20 is held and fixed to the fuel tank T by the driving circuit receiving member 24 made of the metalmaterial, itis possible to easily form thelidmember20 with the synthetic resin materiel without preparing a peculiar new pressing member.

Further' since the strainer is previously arranged so as to be received within the strainer receiving recess portion 20E of the lid member 20 at a time of mounting the fuel pump E to the lid member 20, the strainer 21 is not brought into contact with the opening portion TA of the fuel tank T and the strainer 21 is not broken at a time of the fuel pump E being received within the fuel tank T. so that it is possible to largely improve an assembling property.

As mentioned above, in accordance with the fuel supply apparatus of the present invention, since the supporting portion supporting the fuel pump and the

strainer receiving recess portion receiving the strainer connected to the pump suction passage of the fuel pump are formed in the fuel tank inner side of the lid member, the discharge passage supplying the fuel discharged from the fuel pump toward the engine is arranged in the lid member through the lid member so as to be open toward the external portion, and the pump driving circuit driving the fuel pump is arranged in the fuel tank outer side of the lid member at the position opposing to the strainer receiving recess portion, it is not necessary to secure the fuel sealing property with respect to the pump driving circuit, and it is possible to achieve the stability of the output performance end the reduction of the manufacturing cost Further, it is possible to restrict the increase of the fuel temperature within the fuel pipe system, it is possible to reduce the generation of the bubbles anditis possible to obtain theimprovedfuelsupplying property. Further, since the pump driving circuit is not directly received in the fuel pump, it is possible to reduce the weight of the fuel pump, it is possible to form the fuel pump compact and it is possible to improve the mounting property to the lid member.

Further, since the pump driving circuit is structured such that one side thereof is indirectly cooled by the fuel which always circulates within the strainer

receiving recess portion, and another side thereof is heat radiated into the atmospheric air via the driving circuit receiving member, it is possible to improve a cooling effect of the pump driving circuit. Further, since the strainer is previously arranged so as to be received within the strainer receiving recess portion, the strainer is not damaged even at a time of closing the opening portion of the fuel tank by the lidmember, and it is possible to improve an assembling property.

Further, since the pump driving circuit is arranged at the position which is not in contact with the discharge passage formed in the lid member, it is possible to restrict the increase of the fuel temperature, and it is possible to restrict the generation of the bubbles within the fuel pipe system.

Further, in accordance with the structure in which the lidmemberis formed with the synthetic resinmaterial, the driving circuit receiving member receiving the pump driving circuit is formed with the metal material, and thelidmemberis mounted to the fueltank vie the driving circuit receiving member,itis possible tocasily form the lid member with the synthetic resin material.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and

which are open to public inspection with this s specification, and the contents of all such papers and

documents are incorporated herein by reference.

All of the features disclosed in this specification

(including any accompanying claims, abstract and lo drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

15 Each feature disclosed in this specification

(including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, 20 each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any 25 novel one, or any novel combination, of the features disclosed in this specification (including any

accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

_b

Claims

WHAT I S CLAIMED I S:

1. A fuel supply apparatus comprising: an opening portion disposed below a fuel tank; and a fuel pump supported by a lid member closing the opening portion, wherein a supporting portion(20D) supporting the fuel pump (E) and a strainer receiving recess portion (20E) receiving a strainer (21) connected to a pump suction passage (5) of the fuel pump (E) are formed in a fuel tank inner side (20C) of the lid member (20), a discharge passage (22) supplying a fuel discharged from the fuel pump (E) toward an engine is arranged in the lid member (20) through the lid member (20) so as to be open toward an external portion, and a pump driving circuit driving the fuel pump (E) is arranged in a fuel tank outer side (20G) of the lid member (20) et a position opposing to the strainer receiving recess portion (20E).

2. A fuel supply apparatus as claimed in claim 1, wherein the pump driving circuit is arranged at a position at which the pump driving circuit is not in contact with the discharge passage (22) formed in the lid member (20).

3. A fuel supply apparatus as claimed in claim 1, wherein the lid memberis formed with a synthetic resin 2,

material, a driving circuit receiving member (24)-

receiving the pump driving circuit (23) is formed with a metal material, and the lid member (20) is mounted to the fuel tank (T) via the driving circuit receiving member 5 (24).

4. A fuel supply apparatus substantially as herein described, with reference to the accompanying drawings.