JP2604077B2 - Pump device with built-in motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump device having a built-in motor, which has a sliding contact surface between a brush and a commutator at one end in the axial direction, and is particularly suitable for a fuel pump device for supplying fuel to an internal combustion engine.

[0002]

2. Description of the Related Art A large number of fuel pump devices using an electric motor as a power source have been used as fuel pump devices for internal combustion engines. In particular, in order to reduce the size of the fuel pump device, for example, a fuel in which a pump and a motor are disposed in the same casing as disclosed in Japanese Patent Application No. 2-83660 (the same applicant as the present application). Pump devices are known. In such a type of fuel pump device, a DC motor driven by supplying a current to an armature by bringing one or more pairs of brushes into contact with a commutator is often used.

However, in the fuel pump device having the above-described structure, the fuel circulating inside the casing and the slit formed between the segments of the commutator frictionally generate a fluid cutting noise, and the fluid cutting noise is generated. It is preferable to mute the sound as much as possible, since the sound becomes noise and deteriorates the sense of hearing and may cause the driver to feel uneasy. Further, such a DC motor has a structure in which a sliding surface of a commutator which is in sliding contact with a brush is provided on an end surface in an axial direction, and a brush is urged toward the sliding surface. Will be noticeable.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, a main object of the present invention is to provide a pump device with a built-in motor that can reduce noise generated during operation. .

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided, in accordance with the present invention, a pump device with a built-in motor which receives both a DC motor and a pump unit in a casing through which the fluid to be handled flows. A brush holder for the DC motor at one end of the casing, and a cover for covering the brush holder, wherein a silencing chamber communicating with the inside of the casing is formed between the brush holder and the cover. This is achieved by providing a pump device with a built-in motor.

[0006]

With this configuration, since the fluid cutting noise generated near the slit portion of the commutator can be absorbed by the silencing chamber, the noise generated from the entire pump device can be reduced.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a preferred embodiment of the present invention.

1 to 3 show a fuel pump device with a built-in motor to which the present invention is applied. This pump device is housed in, for example, a fuel tank of a vehicle.

As shown in FIG. 2, the left end of the casing body 1 having a cylindrical shape with both ends opened is shown in FIG.
A pump housing 3 constituting the pump section 2 is fitted to one end of the casing main body 1 so as to close the open end. A brush holder 4 and a terminal holder 5 as a cover for covering the brush holder 4 are provided at the right end of the casing body 1 in FIG. 2 so as to close the other open end of the casing body 1. It is fitted.

The pump housing 3 is a metal inner housing 3a which is superposed on each other and has a substantially disc shape.
And an outer housing 3b.
The annular step 3c provided on the outer peripheral portion of the casing body 1
The thinned end portion of the casing main body 1 is caulked radially inward toward the annular step portion 3d of the outer housing 3b which is overlapped with the corresponding step portion 1a.

In the pump section 2, a fuel inlet 6 extending in the axial direction is opened in the outer housing 3b, and a fuel filter (not shown) is attached to the fuel inlet 6. A hole 7 formed in the center of the inner housing 3a in the axial direction is provided with one end 8 of a rotating shaft 8.
a is supported via a bush 9 as a sliding bearing. The other end 8b of the rotary shaft 8 is rotatably supported via a bush 10 as a sliding bearing fixed to the brush holder 4.

A disk-shaped pump rotor 11 is mounted on the rotating shaft 8 at the extreme end on the one end 8a side of the rotating shaft 8. An empty chamber 12 for receiving the pump rotor 11 is formed at the center of the opposing surfaces of the housings 3a and 3b, and an annular pump chamber 13 is provided at the outermost part. The inner housing 3a has an opening 1 for communicating a part of the pump chamber 13 with the inside of the casing body 1.
4 and the fuel inlet 6 provided in the outer housing 3b communicates with another part of the pump chamber 13, so that the fuel inlet 6 and the opening 14
The fuel can be pumped from the fuel inlet 6 toward the inside of the casing body 1 as the pump rotor 11 rotates.

An armature 15 is integrally provided at the center of the rotating shaft 8. The armature 15 is of a known type in which a copper wire is wound around a core 16 formed by stacking steel plates, for example. Winding 17 wound around core 16
Is electrically connected to a commutator 18 integrally and concentrically fixed to the right side of the rotating shaft 8 in FIG. Here, a sliding contact surface 19a with the brush 29, which will be described later, of the commutator 18 is provided on one end in the axial direction, that is, on the right end surface in FIG. In addition, the commutator 18
Eight segments 19 are molded by arranging them on a common circumference with a predetermined gap. Therefore, slits 20 are formed radially between adjacent segments 19 on the right end face of the commutator 18 in FIG.

On the inner peripheral surface of the casing body 1 corresponding to the outer peripheral portion of the armature 15, for example, two semi-cylindrical permanent magnets 21 are fixed concentrically to the armature 15 at intervals. . Between the two permanent magnets 21,
An extension 4b of the brush holder 4 is interposed between the two permanent magnets 21.
Is fixed.

The brush holder 4 and the terminal holder 5 are made of synthetic resin which are superposed on each other and are formed in a substantially disc shape, and an annular step 4 a provided on the outer peripheral portion of the brush holder 4 corresponds to the casing 1. The thinned end (the right side in FIG. 1) of the casing 1 is caulked radially inward toward the annular step 5a of the terminal holder 5 that overlaps with the end 1b. .

A fuel discharge pipe 22 is integrally formed on the terminal holder 5 so as to project outward in the axial direction.
Is connected to the inside of the casing main body 1 through a discharge hole 23 formed so as to penetrate the brush holder 4 in the axial direction. A check valve 2 is provided in the through hole of the discharge pipe 22.
4, the valve body 24a of which is provided with a compression coil spring 24b.
Urged toward the inside of the casing body 1. A relief valve 26 is provided below the terminal holder 5 in FIG. 3 to release an excessive discharge pressure when the discharge pressure of the fuel becomes abnormally high. 26b urges the inside of the casing body 1.

A pair of brush guide holes 28 are formed inside the casing body 1 of the brush holder 4 (FIG. 1). In the brush guide hole 28, for example, a graphite brush 29 is movably received in the axial direction. The brush 29 is urged toward the casing body 1 by a compression coil spring 30.

As shown in the upper part of FIG. 2, a gap 31 is formed between the brush holder 4 and the terminal holder 5 as a noise reduction chamber. The inside of the casing body 1 is communicated with a through hole 32 formed so as to penetrate the casing body 1.

Next, the operation of the pump device with a built-in motor according to the present invention will be described. When current is supplied to the winding 17, the rotating shaft 8, the armature 15, the commutator 1
8. The pump rotor 11 rotates integrally. Then, the fuel sucked from the fuel suction port 6 circulates through the inside of the casing main body 1 from the pump chamber 13 and is sent to the discharge pipe 22 through the check valve 24 under pressure.

At this time, the gap between the respective segments 19 formed in the commutator 18, that is, in this case, the friction between the eight slits 20 and the fuel generates a fluid cutting noise. This fluid cutting noise is absorbed inside the gap 31 through the through hole 32. Therefore, no fluid cutting noise leaks out of the casing body 1. This means that when the noise generated from the pump device shown in Table 1 was measured, the noise was 5.2 (dB) when the terminal voltage of the DC motor was 12 (V).
When the terminal voltage is 13.5 (V),
This is demonstrated by the noise reduction of 7.3 (dB).

[0021]

[Table 1]

[0022]

As is apparent from the above description, according to the pump device with a built-in motor according to the present invention, the silencing chamber formed between the brush holder and the cover communicates with the inside of the casing body. Thereby, the fluid cutting noise generated in the slit portion of the commutator can be absorbed. Therefore, the noise generated from the pump device is reduced, and an environment in which the driver can drive safely can be provided.

[Brief description of the drawings]

FIG. 1 is an end view of a built-in motor type pump device to which the present invention is applied, as viewed from a pump unit side.

FIG. 2 is a sectional view taken on line II-II of FIG. 1;

FIG. 3 is a partial sectional view taken on line III-III of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing main body 1a, 1b Corresponding end part 2 Pump part 3a Inner housing 3b Outer housing 3c, 3d, 4a, 5a Annular step part 4 Brush holder 5 Terminal holder 6 Fuel inlet 7 Hole 8 Rotary shaft 9, 10 Bush 11 Pump rotor 12 Vacuum chamber 13 Pump chamber 14 Opening 15 Armature 16 Core 17 Winding 18 Commutator 19 Segment 20 Slit 21 Permanent magnet 22 Discharge pipe 23 Discharge hole 24 Check valve 24a, 26a Valve body 24b, 26b, 30 Compression coil spring 26 Relief valve 28 brush guide hole 29 brush 31 gap 32 through hole

Claims (1)

(57) [Claims] 1. A pump device with a built-in motor, wherein both a DC motor and a pump unit are received in a casing through which a fluid to be handled flows, wherein the DC motor is provided at one end of the casing. And a cover for covering the brush holder, wherein a silencing chamber communicating with the inside of the casing is formed between the brush holder and the cover. Pump device.