JPH0540316Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fuel pump for pumping and supplying fuel in a fuel tank to, for example, an automobile internal combustion engine. This invention relates to an oil-immersed fuel pump that allows fuel to flow through the air.

[Conventional technology]

Conventionally, fuel pumps used in internal combustion engines for automobiles include a casing body with a cover made of synthetic resin, and a roller vane-type fuel pump that is installed inside the casing body and pumps fuel from one side of the casing body to the other side. A rotary pump section, an electric motor located within the casing body to rotationally drive the rotary pump section, and a brush holder formed on the cover to hold a brush that slides into contact with a commutator of the electric motor. The composition is known.

In the above-mentioned fuel pump, the rotation of the electric motor rotates the rotary pump part, sucks the fuel in the fuel tank from one side of the casing body, circulates it inside the casing body, and supplies the fuel from the other side to the internal combustion engine. It is now being discharged.

[Problem that the invention attempts to solve]

By the way, the cover that closes the casing body is made of synthetic resin so that the discharge port and relief port can be integrally molded, but if the brush holder is also integrally molded with the cover, synthetic resin There is a drawback that the sliding surface of the brush holder cannot obtain sufficient flatness due to shrinkage during curing. For example, the flatness standard
When the flatness of the actually molded cover is set to 100 μm, the flatness of the actually molded cover is approximately 120 to 180 μm, which may deteriorate the sliding properties of the brush against the brush holder, resulting in poor contact between the brush and commutator, uneven wear, or the brush It has the disadvantage of poor workability when inserted into a holder.

The present invention was developed in view of the above-mentioned drawbacks of the prior art, and the problems to be solved by the present invention are as follows:
When the brush holder is integrally molded with the cover using synthetic resin, the brush holder is formed so that the brush can slide smoothly, preventing poor contact and uneven wear of the brush, and improving assembly workability. There is a particular thing.

[Means for solving problems]

In order to solve the above-mentioned problems, the configuration adopted by the present invention includes a rotary pump part inside the casing body that pumps fuel from one side of the casing body to the other, and a rotary pump part that rotates the rotary pump part. An electric motor is provided to drive the casing body, and a synthetic resin cover that covers the casing body is integrally formed with a brush holder for holding a brush that slides into contact with the commutator of the electric motor, and the inner surface of the brush holder is configured to hold a brush that is in sliding contact with the commutator of the electric motor. The brush is formed on the sliding surface of the brush having long grooves along the sliding direction, and a lubricating liquid film is formed by the fuel flowing into the long grooves.

[Effect]

Long grooves are formed along the brush sliding direction on the brush holder's brush sliding surface to reduce the contact area with the brush, so when the cover and brush holder are integrally molded, the brush sliding will be prevented by shrinkage during curing. Even if the contact surface is deformed, the flatness of the brush sliding contact surface can be prevented from decreasing, and the brush can be slid smoothly. In addition, since the fuel flowing in the fuel pump flows into the long groove, a lubricating liquid film is formed between the brush sliding surface and the brush by this fuel.
This further improves the sliding properties of the brush.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

In the figure, reference numeral 1 denotes a casing body made of a metal cylinder constituting a casing A, and a turbine-type pump section 2 for pumping fuel from one side of the casing body 1 to the other side is provided at one end side of the casing body 1. It is being Reference numeral 3 denotes a pump housing that constitutes the turbine type pump section 2 and covers one end side of the casing body 1. The pump housing 3 is composed of an outer housing 3A and an inner housing 3B. Reference numeral 4 denotes a closed vane type turbine which is rotatably housed in the pump housing 3 while being inserted through a fixed shaft 12 (to be described later), and 5 is a fuel located on the outer peripheral side of the turbine 5 and formed in the pump housing 3. The starting end of the fuel flow path 5 opens at the lower surface of the outer housing 3A and serves as a suction port 5A communicating with a fuel tank (not shown). On the other hand, the terminal end of the fuel flow path 5 opens at the lower surface of the outer housing 3A, and a return port 5 communicates with the fuel tank.
A discharge port 5C is formed in the inner housing 3B and opened to the inside of the casing body 1.

Thus, the turbine type pump section 2 according to this embodiment includes a pump housing 3 that covers one end of the casing body 1, a turbine 4 rotatably provided within the pump housing 3, and a turbine 4 on the outer circumferential side of the turbine 4. The fuel passage 5 is located in the pump housing 3, and has a starting end serving as a suction port 5A, and a terminal end serving as a return port 5B and a discharge port 5C. A valve chamber 6 is provided between the fuel flow path 5 and the return port 5B, and a reed valve (not shown) for opening and closing the return port 5B is provided within the valve chamber 6.

Next, 7 is an upper cover fitted to the other end of the casing body 1 facing the pump housing 3, and the upper cover 7 includes a disc-shaped cover body 7A;
A peripheral wall portion 7B provided around the outer periphery of the cover body 7A.
and each pair of wide fitting protrusions 7C, 7C and narrow fitting protrusions 7 formed protrudingly on the end surface of the peripheral wall portion 7B.
D, 7D, an annular rib 7E located inside the peripheral wall 7B and protruding from the lower surface of the cover body 7A at the same height as the peripheral wall 7B, and radially extending between the annular rib 7E and the peripheral wall 7A. The upper cover 7 is formed of a plurality of vertical ribs 7F, 7F, . and,
The upper cover 7 is provided with a positive terminal 8A and a negative terminal 8B penetrating from the upper surface to the lower surface, and a plurality of connection terminals 9, 9, . . . are implanted in the lower surface. Further, a discharge port 10 is formed in the center of the upper cover 7, and a relief port 11 is formed near the outer periphery.

Reference numeral 12 indicates a fixed shaft installed between the upper cover 7 and the pump housing 3, and 13 indicates a DC electric motor provided within the casing body 1 for rotationally driving the turbine 4 of the turbine type pump section 2. The electric motor 13 includes a stator 14 inserted into the casing body 1, a rotor 15 rotatably supported by the fixed shaft 12, and the rotor 15.
a multi-pole coil 16 wound around the rotor 1;
The commutator 17 is provided on the other axial side of the rotor 15 and rotates integrally with the rotor 15, and a pair of brushes 18, 18 are supported by a brush holder 20, which will be described later, and are in sliding contact with the commutator 17. There is. A sleeve-shaped joint 19 is provided on the fixed shaft 12 and located between the rotor 15 and the turbine 4.
The protrusion 19A protruding from the lower end of the rotor 9 engages with the turbine 4, and the protrusion 15A protruding from one end of the rotor 15 engages with the joint 19, whereby the rotor 15 and the turbine 4 rotate integrally. I'm starting to do that.

Next, reference numerals 20, 20 indicate a pair of brush holders integrally formed on the upper cover 7 to slidably hold each brush 18. Each brush holder 20 has an upper surface portion 20A provided between the peripheral wall portion 7B and the annular rib 7E of the upper cover 7, and is protruded from opposite sides of the upper surface portion 20A in the width direction along the radial direction of the upper cover 7. Left and right side parts 20B, 2
0C, and a lower surface portion 20 formed at the lower ends of the left and right side portions 20B and 20C facing the upper surface portion 20A.
D is formed into a rectangular frame shape. 2
1, 21, . . . are a plurality of cross-sectional long grooves recessed in the inner surface of the upper surface portion 20A along the sliding direction of the brush 18, and each of the long grooves 21 is separated by a predetermined interval in the width direction of the upper surface portion 20A. By arranging the brushes in a row, the inner surface of the upper surface portion 20A forms a brush sliding contact surface 22 in the shape of a narrow band.

In addition, in the figure, 23 is a notch groove formed in the left side surface portion 20B, and a pressure spring (not shown) stretched between the upper cover 7 and the brush 18 is installed in the notch groove 23. It's starting to fit loosely. Also,
Reference numeral 24 denotes a U-shaped notch groove formed in the lower surface portion 20D, into which a wiring (not shown) connected to the brush 18 is loosely fitted.

The fuel pump according to this embodiment is constructed as described above, and the operation itself of driving the turbine type pump section 2 to rotate by the rotation of the electric motor 13 and pumping fuel from one side of the casing A to the other side is as follows. , there is no substantial difference from the prior art.

According to this embodiment, the brush holder 20
A plurality of long grooves 21, 21, . . . are provided in the upper surface portion 20A along the sliding direction of the brush 18, and the brush 18
The contact area of the brush sliding contact surface 22 that comes into contact with the brush is made small. As a result, brush holder 2
To effectively prevent the flatness of the brush sliding surface 22 from deteriorating even if the brush sliding surface 22 is deformed due to contraction etc. during resin curing when the brush sliding surface 22 and the cover 7 are integrally molded. The brush sliding contact surface 2
The flatness of 2 can be made to meet the standard. Further, since the fuel flowing in the casing A flows into the long groove 21, the brush 1 is
A lubricating liquid film can be formed between the brush 8 and the brush sliding contact surface 22, which allows the brush 18 to slide more smoothly and eliminates defects due to poor contact between the brush 18 and the commutator 17 and twisting of the brush 18. It is possible to prevent the brush from decreasing, etc., and to extend the life of the brush 18.

In this embodiment, the long groove 21 is formed in the upper surface portion 20A of the brush holder 20, but the left and right side portions 20B, 20C and the lower surface portion 20
Similarly, the inner surface of D may also be a brush sliding contact surface with long grooves 21 formed therein. Furthermore, although this embodiment uses the turbine type pump section 2 as the rotary pump section, the present invention can also be applied to a fuel pump using a roller vane type pump section.

[Effect of idea]

According to the present invention configured as detailed above,
Since long grooves are formed on the brush sliding contact surface of the brush holder to reduce the contact area between the brush sliding contact surface and the brush, when the cover and brush holder are integrally molded, the brush will shrink due to shrinkage during curing. Even if the sliding surface is deformed, the flatness of the brush sliding surface can be prevented from decreasing, and the brush can be slid smoothly. In addition, the fuel flowing in the fuel pump is allowed to flow into the long groove, and this fuel forms a lubricating liquid film between the brush sliding surface and the brush, which improves the sliding performance of the brush. It is possible to make the fuel pump even better, and to prevent poor contact and uneven wear of the brushes, thereby extending the life of the fuel pump.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of a fuel pump according to an embodiment of the present invention, Fig. 2 is a front view of an upper cover integrally formed with a brush holder, and Fig. 3 is a partially cutaway bottom view of Fig. 2. It is. DESCRIPTION OF SYMBOLS 1... Casing body, 2... Turbine type pump part, 7... Upper cover, 13... Electric motor, 1
7... Commutator, 18... Brush, 20...
Brush holder, 21...long groove, 22...brush sliding contact surface.

Claims (1)

[Scope of utility model registration request] A rotary pump section for pumping fuel from one side of the casing body to the other side and an electric motor for rotationally driving the rotary pump section are provided in the casing body, and a synthetic resin cover for covering the casing body. is integrally formed with a brush holder for holding a brush that slides in contact with the commutator of the electric motor, and the inner surface of the brush holder is formed into a brush sliding surface having a long groove along the sliding direction of the brush, A fuel pump in which a lubricating liquid film is formed by the fuel flowing into the long groove.