WO2009139130A1

WO2009139130A1 - Fuel pump

Info

Publication number: WO2009139130A1
Application number: PCT/JP2009/001996
Authority: WO
Inventors: 堀底伸一郎; 中村太一; 本間文司; 葉山恵三; 鵤木孝夫; 金子義弘; 野末裕
Original assignee: 株式会社ミツバ
Priority date: 2008-05-12
Filing date: 2009-05-07
Publication date: 2009-11-19
Also published as: JPWO2009139130A1; BRPI0911560A2; BRPI0911560B1; JP5325881B2

Abstract

Provided is a fuel pump of such a type that an alcohol-containing fuel flows through an electric motor (1), of which the life can be prevented from being shortened by suppressing a metal around a brush holder from being electrolytically corroded and extremely thinned by alcohol. A bracket (4) pivotally supporting an armature core (6) is divided into a first bracket (10) on which brush holder parts (10b) are formed and a second bracket (12) on which a terminal support part (12c) is formed. Partition surface parts (10h, 12f) fitted to each other in a stacked state are formed on both brackets (10, 12), respectively, to form a positive pole chamber (X) and a negative pole chamber (Y) by partitioning between the brush holder part for positive pole and the terminal support part and the brush holder part for negative pole and the terminal support part.

Description

Fuel pump

The present invention belongs to the technical field of a fuel pump that supplies a fuel containing an alcohol component in particular.

In general, an electric motor is used as a drive source of a fuel pump that flows out (discharges) inflowed (suctioned) fuel. Among such fuel pumps, there is one in which fuel flows directly in the electric motor. Recently, however, alcohol (especially ethanol) is sometimes used as a fuel component, but the alcohol functions electrochemically as an acid because of the presence of a hydroxyl group (—OH). As a result, the fuel is used as a medium (solvent). ) exchanges charge between the electrodes occurs as this ion (H + as a ^result, -O ^-) of the metal component electroerosion constituting the armature core (rotor) is the flow (becomes a factor to corrode) Yes.
Incidentally, some fuel pumps allow fuel to flow (pass) through an electric motor (see, for example, Patent Documents 1 and 2).

JP-A-9-112376 JP 2005-307768 A

In such a case, the brush holder, lead wire (pigtail) connected to the brush, terminal plate connected to the lead wire, metal components such as copper contained in the brush, and a bullet machine for pressing the brush, etc. However, the brush holder part is eroded by the ions that move when the metal component moves because the fuel that exists around the positive and negative brushes serves as a medium. This electric corrosion becomes more prominent as the alcohol content becomes higher, and there is a problem that the durability of the electric motor is lowered. This is a problem to be solved by the present invention.

The present invention has been created in view of the above circumstances and has been created for the purpose of solving these problems. The invention of claim 1 is directed to a pump section for discharging the fuel that has flowed in, and the pump section. In the fuel pump configured to flow the inflowing fuel through and out of the electric motor, the electric motor is provided with a permanent magnet on an inner peripheral surface thereof. A cylindrical yoke, an armature core having a core around which a coil is wound and supported rotatably, a commutator provided at one end of the armature core, and a pair of brushes that are in sliding contact with the commutator A bracket for forming a terminal support part for supporting a pair of external power connection terminals and a brush holder part for supporting the external power connection terminal. A partition surface for forming a positive electrode chamber and a negative electrode chamber is formed by partitioning between the positive electrode brush holder and terminal support and the negative electrode brush holder and terminal support. This is a fuel pump.
According to a second aspect of the present invention, the bracket includes a first bracket on which the brush holder portion is formed and a second bracket on which the terminal support portion is formed, and the partition surface portion is provided on at least one of the first and second brackets. The fuel pump according to claim 1, wherein the fuel pump is formed.
According to the invention of claim 3, the partition surface portion is formed on each of the first and second brackets, and the partition surface portion formed on one bracket is formed as a pair, and the partition groove is formed between the opposing surfaces. 3. The fuel pump according to claim 2, wherein the partition surface portion formed on the other bracket is fitted into the partition groove. 4.
The invention according to claim 4 is the fuel pump according to claim 3, wherein the fitting of the partition surface portion into the partition groove is press-fitting.
According to a fifth aspect of the present invention, in the electric motor according to any one of the first to fourth aspects, the fuel passage is formed so that the fuel passes through the partition surface portion and reaches the fuel outlet. It is a pump.
According to a sixth aspect of the present invention, the first bracket is formed with a brush holder for a positive electrode and a brush holder for a negative electrode, and the partition surface surrounds each brush holder and is fitted to the inner peripheral surface of the second bracket. The fuel pump according to claim 3, further comprising a mating wall portion.

According to the first aspect of the present invention, since the bracket on which the paired brush and terminal are supported is partitioned into the positive electrode chamber and the negative electrode chamber by the partition surface portion, the fuel containing the alcohol component is contained in the electric motor. Even if it passes through, the free movement of ions between the two poles in the bracket is restricted, so that the electrolytic corrosion of the brush and the terminal can be reduced and the life can be prevented from being shortened.
Even if the bracket is divided into a first bracket where the brush holder portion is formed and a second bracket where the terminal support portion is formed, the partition surface portion can be formed. it can.
By setting it as invention of Claim 3, it can be set as the labyrinth structure which partition surface parts mutually fitted, and a more reliable partition can be performed.
By setting it as invention of Claim 4, a clearance gap disappears between a partition surface part and the said partition groove | channel, and the free movement of ion can be restrict | limited more.
According to the invention of claim 5, when the alcohol-containing fuel passes through the electric motor, a fuel passage can be formed by effectively using the partition surface portion, and a large amount of fuel is contained in each partitioned chamber. It can be avoided that the flow of ions promotes the movement of ions and promotes electric corrosion.
By setting it as invention of Claim 6, it can be set as the more reliable labyrinth structure which partition surface parts mutually fitted, and a partition with a high effect can be performed.

(A), (B), and (C) are a perspective view, a plan view, and a bottom view of a motor part of a fuel pump. (A) and (B) are the longitudinal cross-sectional views of the part which passes the outflow port part of a fuel pump, and the longitudinal cross-sectional view of the part which passes a pair of brush. (A), (B), (C), and (D) are a plan view, a bottom view, a bottom perspective view, and a plan perspective view of the first bracket. (A), (B), (C), and (D) are sectional views taken along lines AA, BB, CC, and DD in FIG. (A), (B), (C), and (D) are a plan view, a bottom view, a bottom perspective view, and a plan perspective view of a second bracket. FIGS. 5A and 5B are cross-sectional views taken along lines AA and BB in FIG. (A), (B), and (C) are AA cross-sectional views of the upper bracket portion in FIG. 1 (B), a BB cross-sectional view in FIG. 7 (A), and a vertical cross-sectional view of the main part of the terminal support portion. is there.

Next, embodiments of the present invention will be described with reference to the drawings. In the figure, 1 is an electric motor, and the electric motor 1 constitutes a motor part (drive part) M of a fuel pump.

The electric motor 1 includes a cylindrical yoke 3 supporting a permanent magnet 2 on an inner peripheral surface, a pair of

brackets

4 and 5 provided at both ends of the cylinder of the yoke 3, and rotatably supported by both

brackets

4 and 5. It is the same as before that it is configured using various members such as the armature core 6 to be used. In the figure, reference numeral 5a denotes a fuel inlet formed in the other bracket 5.

The armature core 6 includes a core portion 7 formed by winding a core plate 7a, in which a resin material 7b is embedded and insert-molded and a coil that cannot be visually seen is wound, and the core portion 7 includes a commutator 8 provided on one end side of the arm 7 and an armature shaft (motor shaft) 9 penetrating the core portion 7 and the commutator 8, and the armature core 6 has an outer peripheral surface of the core portion 7 that is a permanent magnet. Each end of the armature shaft 9 is rotatably supported by the

brackets

4 and 5 so as to be opposed to each other with a gap (air gap) between the inner peripheral surfaces of the two and is incorporated in the yoke 3. .

One of the brackets 4 and 5 (hereinafter, for the sake of convenience, one is directed to the upper side and the other is directed to the lower side, but the directionality is not limited thereto). A first bracket 10 formed with a shaft holder 10b for supporting the shaft 11 and a brush holder portion 10b that slidably contacts the axially outer end surface of the commutator 8 is formed, and a base of an elastic machine 11a for repressing the brush 11. The second bracket 12 in which a terminal support portion 12c through which a bullet support portion 12a for supporting the end portion, an outlet portion 12b for fuel outflow and a terminal 13 for connecting an external power source are formed is disposed on the lower side. These configurations will be described in detail below.

The lower first bracket 10 has a plate surface portion 10c, and is formed with upper and

lower protrusion portions

10d and 10e protruding upward and downward with the plate surface portion 10c as a boundary. The lower protrusion portion 10e is cylindrical. And is set so as to be fitted into the upper end of the yoke 3. Further, the plate surface portion 10c includes the shaft support portion 10a having a cylindrical shape with the upper end opened at the lower end and a pair of cylindrical brush holder portions 10b opened at both upper and lower ends with respect to the plate surface portion 10c. A passage hole 10f through which fuel passes is formed while projecting upward and downward. In addition, a through groove 10g through which the pigtail 11b connected to the brush 11 penetrates in a vertically movable manner is formed in a portion protruding upward from the plate surface portion 10c of the brush holder portion 10b.
The upper projecting portion 10d has a semi-cylindrical shape having partition surface portions 10h that pass through the passage hole 10f and the shaft support portion 10a and that face each other so as to partition (divide into two) the pair of brush holder portions 10b. A partition groove portion 10i is formed between the pair of partition surface portions 10h facing each other. Further, a portion corresponding to the passage hole 10f of the partition surface portion 10h is formed with a cylindrical portion 10j having a diameter larger than that of the passage hole 10f.

On the other hand, the upper second bracket 12 is formed with an upper surface portion 12d and a peripheral surface portion 12e as much as possible to have a dome-shaped cylindrical shape with an open lower end and a closed upper end. The peripheral surface portion 12e is formed of the upper protruding portion. It is set to be externally fitted to 10d. Further, the upper surface portion 12d is formed with a cylindrical munition support portion 12a projecting vertically from the upper surface portion 12d so that the lower end faces the upper end of the brush holder portion 10b. A support plate 14 for supporting the upper end of the ammunition 11a is fixed to the support portion 12a. Further, as described above, the upper surface portion 12d is formed with the terminal support portion 12c through which a pair of the outflow port portion 12b for fuel outflow and the terminal 13 for connecting the external power supply penetrates upward. A check valve 16 is provided at the outlet portion 12b.
Reference numeral 12f denotes a partition surface portion formed on the second bracket 12. The partition surface portion 12f is formed by an upper surface portion 12d and a peripheral surface portion 12e so as to partition (divide into two) the pair of bullet support units 12a and the pair of terminals 13. The inside of the enclosed second bracket 12 is divided into two, and the partition surface portion 12f is formed when the

brackets

10 and 12 are assembled together by externally fitting the peripheral surface portion 12e to the upper protruding portion 10d as described above. Are set so as to be press-fitted into the partitioning groove portion 10i on the first bracket 10 side, so that the armature core of the bracket 4 is provided on the side opposite to the side where the armature core of the bracket 4 is provided. Is divided in a state where there is no gap between the plus side electrode chamber X in which the other side is provided, the other side is the minus side brush, and the minus side electrode chamber Y in which the terminal 13 is provided. . Further, the partition surface portion 12f is formed with a communication portion 12h that is fitted into the cylindrical portion 10j and has a communication hole 12g that communicates with the passage hole 10f and the outlet portion 12b.
The pump portion P is configured such that an impeller 17 fixed to the armature shaft 9 is incorporated between the bracket 5 and a casing 15 provided in a laminated manner on the outside of the bracket 5. When the impeller 14 rotates as the armature shaft 9 is driven to rotate, fuel flows into the pump part P from an inlet (suction port) 15a provided in the casing 15, and the fuel that flows into the motor part M as described above. It flows out from the outflow port 12b through the inside and is supplied to the internal combustion engine.

In the embodiment of the present invention configured as described above, the fuel that has flowed into the yoke 3 by the pump provided in the pump chamber P (not shown) passes through the bracket 4 and flows out from the outlet portion 12b. In this case, the bracket 4 is divided into the plus pole chamber X in which the plus brush 11, the pigtail 11b, the bullet machine 11a, the terminal 13, and the bullet support plate 14 exist, and the minus brush 11 by the

partition surface portions

10h and 12f. , The pigtail 11b, the ammunition 11a, the terminal 13, and the negative electrode chamber Y in which the ammunition support plate 14 is present. As a result, free ions are allowed to flow between the positive side metal and the negative side metal. The flow is obstructed, and the thinning due to the occurrence of electrolytic corrosion can be reduced, and the shortening of the life can be prevented.

Moreover, in this case, the bracket 4 is divided into a first bracket 10 on which the brush holder portion 10b for supporting the brush 11 is formed and a second bracket 12 on which the terminal support portion 12c for supporting the terminal 13 is formed, Of these

brackets

10, 12, the first bracket 10 is formed with a pair of partition surface portions 10h, and the second bracket 12 is formed with a partition surface portion that fits into a partition groove 10i formed between the pair of partition surface portions 10h. Since 12f is formed, it becomes a partition in a labyrinth structure state in which the three

partition surface portions

10h, 12f, and 10h are fitted to each other, and the function of preventing free movement of ions in the fuel is improved, thereby preventing electrolytic corrosion. Will greatly contribute. And in this Embodiment, since insertion of the partition groove | channel 10i and the partition surface part 12f is press-fitting, a clearance gap disappears between the mutual opposing surfaces to insert, and the function of preventing free movement of ions further improves.

In addition, in this case, the fuel that has entered the yoke 3 passes through the passage hole 10f formed in the partition groove 10i sandwiched between the partition surface portions 10h of the first bracket 10, and the communication hole 12g formed in the partition surface portion 12f of the second bracket 12. Therefore, the amount of fuel flowing into the positive electrode chamber X and the negative electrode chamber Y is so small that a positive fuel flow can be avoided. The total amount of contact of alcohol with the metal member is reduced, so that electric corrosion can be prevented. In addition, since such a fuel path can be effectively used by the partition surface portion that partitions the positive electrode chamber X and the negative electrode chamber Y, the structure can be simplified.

Of course, the present invention is not limited to the above-described embodiment, and the bracket 4 can be implemented even if it is not divided into the first and

second brackets

10 and 12, Moreover, in what was divided | segmented into the 1st, 2nd bracket, even if it forms in at least one

bracket

10 or 12, as a partition surface part, Furthermore, when fitting partition parts, Needless to say, a structure in which four or more partition surfaces are fitted may be employed.

The present invention belongs to the technical field of a fuel pump that supplies a fuel containing an alcohol component in particular. Even if the fuel containing an alcohol component passes through the electric motor, the bracket is configured as in the present invention. In this case, the free movement of ions between the two poles is restricted, so that the electrolytic corrosion of the brush and the terminal can be reduced, and the shortening of the service life can be prevented. In addition, there is an industrial applicability that reliable partitioning can be performed by forming a labyrinth structure in which the partition surface portions are fitted to each other.

DESCRIPTION OF SYMBOLS 1 Electric motor 2 Permanent magnet 3

Yoke

4, 5 Bracket 6 Armature core 7 Core part 8 Commutator 10a Shaft support part 10b Brush holder part 10c Plate surface part 10h Partition surface part 10i Partition groove part 10f Passing hole 11 Brush 11a Bullet 12 Second bracket 12a Machine support part 12b Outlet part 12c Terminal support part 12d Upper surface part 12f Partition surface part 12g Communication hole 13 Terminal

Claims

In a fuel pump comprising a pump unit for flowing out inflowed fuel and an electric motor for driving the pump unit, wherein the inflowed fuel is configured to flow out through the electric motor The electric motor includes a cylindrical yoke having a permanent magnet provided on an inner peripheral surface thereof, an armature core having a core portion around which a coil is wound and rotatably supported, and one end portion of the armature core And a bracket formed with a terminal holder for supporting a pair of external power connection terminals and a brush holder portion for supporting a pair of brushes in sliding contact with the commutator. In this case, the bracket is divided between the brush holder for positive electrode and the terminal support and the brush holder for negative electrode and the terminal support. Las electrode chamber, the fuel pump characterized in that the partition surface portion for forming the negative electrode chamber are formed.
The bracket includes a first bracket on which the brush holder portion is formed and a second bracket on which the terminal support portion is formed, and the partition surface portion is formed on at least one of the first and second brackets. The fuel pump according to claim 1.
The partition surface portion is formed on each of the first and second brackets, and the partition surface portion formed on one bracket is formed as a pair and has a partition groove between opposite sides, The fuel pump according to claim 2, wherein a partition surface portion formed on the bracket is fitted into the partition groove.
The fuel pump according to claim 3, wherein the fitting of the partition surface portion into the partition groove is press-fitting.
The fuel pump according to any one of claims 1 to 4, wherein the electric motor is formed with a fuel passageway through which the fuel passes through the partition surface portion to reach the fuel outlet.
The first bracket has a positive electrode brush holder portion and a negative electrode brush holder portion, and the partition surface portion has a wall portion that surrounds each brush holder and fits to the inner peripheral surface of the second bracket. The fuel pump according to claim 3.