JPH10174375A - Commutator and method of manufacturing the same - Google Patents

Abstract

(57) [Problem] To provide an inexpensive commutator that is easy to manufacture. SOLUTION: Tin (Sn) plating is applied to at least a connection surface between a disc-shaped copper terminal base material having a claw portion 63a on an outer periphery and a contact portion base material made of a carbon material to form a bonding layer 63b. , 62a. Bonding layer 62a and bonding layer 6
Heat treatment is performed in a state where 3b and 3b are brought into close contact with each other, and the joining layers are melted to join the terminal portion base material and the contact portion base material. After the resin molding, the segments are divided into respective segments, and the contact portions 62 and the terminal portions 63 are formed. Since the bonding layers formed on the connection surfaces are melted by a heat treatment to bond the contact portion base material and the terminal portion base material, manufacturing is facilitated. Furthermore, since an expensive soldering device is not required, manufacturing costs can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a commutator and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a fuel pump for an automobile, for example, an electromagnetically driven fuel pump including a motor section and a pump section has been widely used. Current is supplied from the power supply to the armature wound with the coil by the contact portion of the commutator divided into a plurality of portions of the motor portion slides with the brush,
The armature rotates. Fuel is sucked up from the fuel tank by the rotation of the armature, and supplied to an internal combustion engine (hereinafter, the “internal combustion engine” is referred to as an engine).

[0003] The contact portion of the commutator is generally made of copper. However, the contact portion made of copper may react with, for example, an oxidized fuel or a fuel containing a sulfur component and corrode. In addition, the generation of conductive copper sulfide may cause the contact portions divided into a plurality of portions to be electrically connected. To prevent the contacts from reacting with the fuel,
As disclosed in U.S. Pat. No. 5,175,463, it is known to form a contact portion with a carbon material.

As a method of electrically connecting a contact portion formed of such a carbon material to a metal terminal portion, a metal plating is applied to the contact portion in advance, and the metal plating surface of the contact portion and the metal terminal portion are soldered. A method of manufacturing a commutator by attaching the same is conceivable.

[0005]

However, in the method of soldering a contact portion having a low-melting-point metal bonding layer and a metal terminal portion, the number of steps for sandwiching a solder material between the contact portion and the metal terminal portion is reduced. Production is complicated because it is required.
Furthermore, since an expensive soldering device is required, there is a problem that it is difficult to reduce the manufacturing cost of the commutator.

[0006] It is an object of the present invention to provide a commutator which is easy to manufacture and inexpensive. Another object of the present invention is to provide an inexpensive fuel pump that is easy to manufacture. Still another object of the present invention is to provide a method of manufacturing a commutator that is easy and inexpensive to manufacture.

[0007]

According to the commutator of the present invention, a low-melting-point metal bonding layer is formed on an electrical connection surface between a contact portion and a terminal portion formed of a carbon material. Since the contact portion and the terminal portion are electrically connected by fusion bonding the joining layers, the connection between the contact portion and the terminal portion can be easily and inexpensively performed as compared with the case of joining by soldering. it can.

According to the commutator of the second aspect of the present invention,
The thickness of the bonding layer formed on the contact portion and the terminal portion is 10 to 5
By setting the thickness to 0 μm, the contact portion and the terminal portion can be reliably electrically and physically connected, and the metal forming the bonding layer can be prevented from protruding from the bonding portion during melting. According to the commutator according to claim 3 or 4 of the present invention,
By joining the locking portion provided on the contact portion and the terminal portion with the mold resin, the contact portion and the terminal portion can be more reliably joined in addition to the fusion joining of the joining layers.

According to the commutator of claim 5 of the present invention,
Even when the concave and convex portions respectively formed in the contact portion and the terminal portion are fitted together, even if the low-melting-point metal melt-bonded located between the contact portion and the terminal portion is melted by the heat at the time of fusing. It is possible to prevent the displacement between the contact portion and the terminal portion. According to the fuel pump of the sixth aspect of the present invention, the fuel pump can be manufactured easily and at low cost.

According to the method for manufacturing a commutator according to claim 7 or 8 of the present invention, a bonding layer of a low melting point metal is formed on each of a terminal portion and a contact portion formed of a carbon material, and the bonding layers are formed. Since the contact portion and the terminal portion are electrically connected by heating and fusion bonding, the commutator can be easily and inexpensively manufactured.

[0011]

Embodiments of the present invention will be described below. (First Embodiment) FIG. 3 shows an example in which the commutator according to the first embodiment of the present invention is applied to an in-tank type fuel pump.

As shown in FIG. 3, the fuel pump 10 includes a pump section 20 and a motor section 30 as an electromagnetic drive section for driving the pump section 20. Motor unit 30
Denotes a DC motor with a brush, and a cylindrical housing 1
1, a permanent magnet 31 is disposed in a ring shape.
The armature 32 is arranged concentrically on the inner peripheral side of the armature.

The pump section 20 comprises a casing main body 21, a casing cover 22, an impeller 23 and the like.
Is formed, for example, by die casting of aluminum. The casing main body 21 is press-fitted and fixed inside one end of the housing 11, and a bearing 24 fitted at the center of the casing main body 21 rotatably supports the rotating shaft 35 of the armature 32. The fuel sucked by the pump unit 20 is supplied to the motor unit 3
It is pumped within 0. On the other hand, the casing cover 22 is fixed to one end of the housing 11 by swaging or the like while being covered by the casing main body 21. A thrust bearing 25 is fixed to the center of the casing cover 22 so that a thrust load of the rotating shaft 35 can be received. A suction port 40 is formed in the casing cover 22, and fuel in a fuel tank (not shown) is drawn into the pump flow path 41 of the pump unit 20 from the suction port 40. Casing body 21 and casing cover 2
2 constitutes one casing, in which the impeller 23 is rotatably accommodated.

A blade is formed on the periphery of the impeller 23, and the fuel sucked into the pump passage 41 from the suction port 40 by the rotation of the impeller 23 is fed into the motor unit 30 by pressure. The armature 32 is rotatably accommodated in the motor unit 30, and a coil (not shown) is wound around the core 32a. The commutator 60 is disposed above the armature 32 in FIG. 3, and power is supplied from a power supply (not shown) to the coil via the terminal 46 embedded in the connector 45, a brush (not shown), and the commutator 60. . A contact portion 62 of the brush and the commutator 60 that slides with the brush is formed of a carbon material.

The commutator 60 includes eight segments 61 divided at equal angular intervals as shown in FIGS. 1 and 2, and a resin support 69 for supporting the segments 61. Each segment 61 includes a contact portion 62 and a contact portion 62
And a copper terminal 63 electrically connected to the terminal. Since the groove 64 dividing each segment 61 reaches the support portion 69, each segment 61 is electrically insulated from each other. The claw portion 63a protrudes to the outer peripheral side of each terminal portion 63, and is electrically connected to the coil.

When the coil of the armature 32 is energized and the armature 32 rotates, the impeller 23 rotates together with the rotating shaft 35 of the armature 32. When the impeller 23 rotates, fuel is sucked into the pump channel 41 from the suction port 40, and this fuel receives kinetic energy from each blade piece of the impeller 23 and is pumped from the pump channel 41 into the motor unit 30. You. The fuel pumped into the motor section 30 passes around the armature 32 and is discharged from the fuel discharge port 43.

Next, a method of manufacturing the commutator 60 will be described. Tin (Sn) plating, which is a low-melting metal, is applied to at least the connection surfaces of the disc-shaped copper terminal base material having the claw portions 63a on the outer periphery and the contact portion base material made of carbon material.
The bonding layers 63b and 62a are formed. Joining layers 63b, 62
The thickness of a is 10 to 50 μm.

A heat treatment is performed to about 230 ° C. in a state where the bonding layers 62a and 63b are in close contact with each other, and the bonding layers are melted to bond the terminal portion base material and the contact portion base material. The support part 69 is formed by molding the resin. The contact portion base material and the terminal portion base material are divided until reaching the support portion 69, and the contact portion 62 and the terminal portion 63 are formed.

After the commutator 60 is formed as described above, the coil is fused to the claw portion 63a to electrically connect the contact portion 62 and the coil. Here, fusing refers to a method in which the coating of the coil is pressed and connected to the claw portion 63a while heating. In the first embodiment, the bonding layers 62a,
63b was formed by tin (Sn) plating, but is not limited to tin but may be magnesium (Mg), aluminum (Al), zinc (Zn), arsenic (As), antimony (Sb), tellurium Te), bismuth (Bi) or the like may be plated. The method for forming the bonding layer is not limited to plating, but may be thermal spraying or vapor deposition.

The thickness of the bonding layers 62a and 63b is set to 10
Although the thickness was set to 50 μm, the plating thickness is desirably 20 μm or more in order to more reliably join, and the plating thickness is desirably 25 μm or less to prevent sagging during melting. Therefore, the plating thickness is more preferably in the range of 20 to 25 μm. In the first embodiment of the present invention described above, a contact layer base material made of a carbon material and a copper terminal portion base material are joined to each other by melting a bonding layer formed on a bonding surface between them by heat treatment. Therefore, compared to a method of joining a contact portion base material made of a metal plated carbon material and a metal terminal portion base material by soldering, a solder material is provided between the terminal portion base material and the contact portion base material. Since the man-hour for sandwiching is not required, manufacturing becomes easy. Furthermore, since an expensive soldering device is not required, manufacturing costs can be reduced.

(Second Embodiment) FIG. 4 shows a second embodiment of the present invention.
Shown in The terminal portion 63 and the contact portion 70 are joined by melting a joining layer of a low melting point metal formed on each joining surface by a heat treatment. An outer peripheral tapered surface 70a and an inner peripheral tapered surface 70b are formed on the inner periphery and the outer periphery of the contact portion 70 so as to move away from each other toward the joint side with the terminal portion 63. Outer peripheral tapered surface 70a and inner peripheral tapered surface 70b
Represents a “locking portion” described in the claims.
Since the support portion 71 is molded so as to cover the outer peripheral taper surface 70a and the inner peripheral taper surface 70b, the contact portion 7
0 and the terminal portion 63 are prevented from peeling off.

The tapered surface formed on the contact portion 70 may be formed on at least one of the inner periphery and the outer periphery. Further, a step or a convex portion may be formed as a “locking portion” on at least one of the inner periphery and the outer periphery of the contact portion instead of the tapered surface. (Third Embodiment) A third embodiment of the present invention is shown in FIG.

The terminal portion 80 of each segment is provided with a through hole 80a as a concave portion, and the contact portion 81 of each segment is formed with a projection 81a as a convex portion at a position corresponding to the through hole 80a. A bonding layer of a low-melting metal is formed on each of the bonding surfaces of the terminal portion 80 and the contact portion 81, and a heat treatment is performed in a state where the protrusions 81a are fitted into the through holes 80a to melt the bonding layer, and The part 80 and the terminal part 81 are joined.

Since the protrusion 81a is fitted into the through hole 80a, the temperature at which the coil 80 is heated to the claw portion 80b of the terminal portion 80 becomes higher than the melting point of the low melting point metal by the heat generated by fusing the coil. Even if the molten metal joining the terminal portion 81 is melted, no displacement occurs between the terminal portion 80 and the contact portion 81. In other words, the protrusion 81 is formed in the through hole 80a.
By fitting a, even if a high heat-resistant coating that does not melt unless it is heated to a higher temperature is applied to the coil, the displacement between the terminal portion 80 and the contact portion 81 does not occur due to fusing heat. Can be joined.

In the third embodiment, the through hole 80a as a concave portion is formed in the terminal portion 80, and the projection 81a as a convex portion is formed in the contact portion 81. However, if the displacement between the terminal portion and the contact portion can be prevented. For this reason, a convex portion may be formed in the terminal portion and a concave portion may be formed in the contact portion. In the above-described embodiment showing the embodiment of the present invention described above, the contact portion formed as a whole in a disk shape was used, but the contact portion was formed in a cylindrical shape as a whole, and a brush was applied to the cylindrical side surface. It is also possible to slide.

In the above embodiments, the commutator of the present invention is applied to an in-tank type fuel pump, but the field of application of the commutator of the present invention is not limited to the fuel pump. .

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line II of FIG. 2 showing a commutator according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a commutator of the first embodiment.

FIG. 3 is a sectional view showing a fuel pump according to the first embodiment.

FIG. 4 is a sectional view showing a commutator according to a second embodiment of the present invention.

FIG. 5 is a sectional view showing a commutator according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Fuel pump 11 Housing 20 Pump part 30 Motor part 32 Armature 60 Commutator 61 Segment (Commutator) 62 Contact part (Commutator) 62a Joining layer 63 Terminal part (Commutator) 63b Joining layer 69 Supporting part (Commutator) Reference Signs List 70 Contact part (commutator) 70a Tapered surface (locking part) 70b Tapered surface (locking part) 71 Support part (commutator) 80 Terminal part (commutator) 80a Through hole (recess) 81 Contact part (commutator) 81a Projection (convex) 82 Support (commutator)

Claims (8)

[Claims] 1. A commutator having a contact portion sliding on a brush and a terminal portion electrically connected to the contact portion,
The contact portion is formed of a carbon material, and a low-melting-point metal bonding layer formed on an electrical connection surface between the contact portion and the terminal portion is fusion-bonded to the contact portion and the terminal. A commutator characterized by being electrically connected to a part. 2. The commutator according to claim 1, wherein the thickness of each of the bonding layers formed on the contact portion and the terminal portion is 10 to 50 μm. 3. It has a resin support part molded so as to cover said terminal part and said contact part, and said contact part is separated from said terminal part by being covered by said support part. 3. A commutator according to claim 1, wherein a locking portion for preventing the commutator is formed on the contact portion. 4. The commutator according to claim 3, wherein the locking portion has a tapered surface. 5. The commutator according to claim 1, wherein a concave portion and a convex portion provided on one of the contact portion and the terminal portion are fitted. 6. A fuel pump using the commutator according to any one of claims 1 to 5. 7. A method of manufacturing a commutator having a contact portion that slides on a brush and a terminal portion that is electrically connected to the contact portion, wherein a bonding layer of a low melting point metal is formed on the contact portion formed of a carbon material. Forming a bonding layer of a low-melting-point metal on the terminal portion; and bringing the bonding layers of the contact portion and the terminal portion into contact with each other and heating to melt-bond the bonding layers. And
Electrically connecting the contact portion and the terminal portion to each other. 8. The method according to claim 7, wherein the bonding layer is formed by any one of plating, thermal spraying, and vapor deposition.