JP4866986B2 - Brush for motor, motor provided with the same, and method for manufacturing brush - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a brush for a motor, a motor including the brush, and a method for manufacturing the brush, and more particularly, a brush for a motor having improved contact resistance and material cost between the brush for the motor and a commutator, and a motor including the brush. The present invention relates to a brush manufacturing method.
[0002]
[Prior art]
As shown in FIG. 4, a metal brush 21 has conventionally been used for a micromotor. The metal brush 21 repeats the movement of moving away from or coming into contact with the commutator 23 while the motor 25 is rotating. For this reason, in order to improve the contact property with the commutator 23, the metal brush 21 is variously devised such as being formed in a leaf spring shape. Further, for good commutation, contact between metals is not preferable, so that expensive noble metal is used as the material of the metal brush 21 or the surface of the metal brush is clad with the noble metal.
[0003]
[Problems to be solved by the invention]
However, as shown in FIG. 4, the conventional metal brush has a large contact area between the contact surface of the metal brush and the commutator, which increases the contact resistance and is likely to be non-conductive when black / brown powder is generated. was there. In addition, since the metal brush uses an expensive noble metal material, there is a problem in that the material cost is increased if the noble metal material is clad on the entire surface of the metal brush as in the past.
[0004]
The present invention has been made in view of the problems described above, and the object of the present invention is to provide a brush for a motor that can reduce the contact resistance and improve the conductivity with respect to the commutator and reduce the material cost. It is providing the motor provided with it, and a brush manufacturing method.
[0005]
[Means for Solving the Problems]
According to the first aspect of the present invention, in a brush for a motor that supplies power to a commutator, a brush body made of metal has a "<" shape, and noble metal plating is applied to a part of the brush body . The convex portion having an arcuate cross section is arranged so that the axial direction of the convex portion is substantially perpendicular to the axial direction of the commutator so as to be in contact with the commutator.
[0006]
For plating the convex portions, for example, gold, silver, or an alloy containing these metals is used. In addition, since the axial direction of the convex portion is disposed substantially perpendicular to the axial direction of the commutator, the circumferential surface of the commutator formed in a cylindrical shape and the circumferential surface of the convex portion having an arcuate cross section Are in contact with each other at substantially right angles. For this reason, a commutator and a convex part will be in a point contact state.
[0007]
According to a second aspect of the invention, in addition to the configuration of the first aspect of the invention, a plurality of the convex portions are arranged in parallel in the axial direction of the commutator.
[0008]
Since a plurality of convex portions are arranged in parallel in the axial direction of the commutator, even if the brush for the motor vibrates due to the rotation of the motor, any convex portion can ensure contact with the commutator. .
[0009]
According to a third aspect of the invention, in addition to the configuration of the first or second aspect of the invention, the convex portion includes a first plating portion and a second plating portion that covers the first plating portion. It is a brush for motors characterized by these.
[0010]
The first plating portion may be formed by noble metal plating, but is preferably formed by metal plating. Further, the second plating part is formed by noble metal plating because it directly contacts the commutator.
[0011]
According to a fourth aspect of the present invention, in the brush for a motor that supplies power to the commutator, a brush body made of metal has a "<" shape, and a part of the brush body contacts the commutator. Thus, a brush for a motor comprising a convex portion having an arcuate cross section formed by noble metal plating.
[0012]
A fifth aspect of the present invention is a motor including the brush according to any one of the first to fourth aspects.
[0013]
According to a sixth aspect of the present invention, in the method for manufacturing a brush for a motor, a first step of performing resist printing of a slit pattern having a predetermined width on a plate material, and a cross-sectional arc shape in which the slit pattern is subjected to metal plating and is in contact with a commutator A second step of forming the convex portion, a third step of applying noble metal plating so as to cover the metal plating, and a fourth step of punching the plate material into a predetermined brush shape.
[0014]
The slit pattern having a predetermined width can be subjected to metal plating of a plurality of brushes at a time in the second step. The metal plating in the second step is preferably a metal such as copper, but may be a noble metal.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the metal brush according to the present embodiment is fixed to the brush base 4 so that the convex portion 2 contacts the commutator 3. As shown in FIG. 2, the metal brush body 1 is formed to have elasticity by bending a plate-like body into a substantially “<” shape. This is to improve the contact with the commutator 3. The surface 1a of the metal brush main body 1 is insulated except for the protrusions 2. On the surface 1 a of the metal brush body 1, two convex portions 2 that are in contact with the commutator 3 are provided in parallel in the axial direction of the commutator 3.
[0016]
As shown in FIGS. 1 and 2, the convex portion 2 is formed in an arc shape in cross section, and is formed in a semi-cylindrical shape along the axial direction of the commutator 3. Two protrusions 2 are provided in parallel even if one protrusion 2 causes a contact failure with the commutator 3 due to vibration of the motor, the other protrusion 2 and the commutator 3 are in contact with each other. It is for keeping it. As shown in FIG. 3B, the convex portion 2 includes a first plating portion 2a and a second plating portion 2b.
[0017]
The first plating portion 2a is formed in a circular arc shape by, for example, copper plating on the surface 1a of the metal brush body 1. Thus, the material cost can be reduced by forming the first plating portion 2a with an inexpensive metal such as copper. Note that the first plating portion 2a is not limited to copper plating, as long as it is formed by metal plating capable of conducting with the commutator 3, and may be formed of other metals or noble metals. Good.
[0018]
The second plating part 2b is formed by applying, for example, hard gold plating so as to cover the first plating part 2a. The thickness of the hard gold plating is formed in consideration of friction with the commutator 3. The second plating portion 2b is not limited to hard gold plating, as long as it is formed by noble metal plating capable of conducting with the commutator 3. The second plating portion 2b is formed of noble metal such as gold, silver, or platinum. It may be.
[0019]
The brush 1 for a motor according to the present embodiment may be any metal as long as the convex portion 2 that contacts the commutator 3 is formed so that the contact resistance with the commutator 3 is reduced. The shape of itself is not limited to a substantially “<” shape. Therefore, for example, when pressing a metal brush main body from the back side of a metal brush, a flat metal brush main body may be sufficient.
[0020]
By using the metal brush 1 formed as described above as the brush of the small motor 5, the conductivity with respect to the commutator 3 is improved and an inexpensive motor can be manufactured.
[0021]
Next, the brush manufacturing method according to the present embodiment will be described with reference to FIG. FIG. 3A is a view of the metal brush manufacturing process as viewed from above, and FIG. 3B is a cross-sectional view of the metal brush.
[0022]
As shown in the first step (1), a metal flat plate serving as a metal brush body is prepared, and as shown in (2), a resist pattern is printed with a slit pattern having a predetermined width on the surface of the metal flat plate. In this slit pattern, since the convex portion is formed by plating, an insulating material is not attached only to a slit portion which is a portion for forming the convex portion. Thus, a plurality of slit portions are formed in parallel on the metal flat plate by performing resist printing of a slit pattern having a predetermined width.
[0023]
As shown in the second step (3), for example, copper plating is applied to the plurality of slit portions to form a first plated portion having an arcuate cross section that contacts the commutator. The plating method is preferably performed, for example, with a body to form a convex portion having a predetermined height. In addition, although the case where copper was used was demonstrated as an example of metal plating, the material of the plating used at a 2nd process is not limited to copper. Therefore, a metal other than copper or a noble metal may be used as long as it can secure a conduction state with the commutator and is an inexpensive metal material.
[0024]
Third Step Next, as shown in (4), hard gold plating is performed so as to cover the copper plating applied in the second step. Since the part formed by this hard gold plating is a part that directly contacts the commutator, it needs to be formed to a predetermined thickness in relation to friction. Is preferable. In addition, although the case where hard gold was used was demonstrated as an example of noble metal plating, the material of the plating used at a 2nd process is not limited to hard gold. Therefore, a noble metal other than hard gold may be used as long as it is a stable noble metal material that can ensure conduction with the commutator and does not chemically change.
[0025]
Fourth Step Next, as shown in (5), a plate material on which a plurality of convex portions are formed is punched into a predetermined metal brush shape.
[0026]
As described above, by forming the convex portion having an arcuate cross section in contact with the commutator on the metal brush body by plating, the brush for the motor has low contact resistance, excellent conductivity, and reduced material cost. Can be manufactured.
[0027]
【Effect of the invention】
The invention according to claim 1 has the effect of reducing the contact resistance and improving the conductivity with respect to the commutator. The contact resistance is reduced because the commutator's axial direction and the convex portion's axial direction are arranged at substantially right angles rather than line contact as in the prior art. This is because the surface and the circumferential surface of the convex portion having an arcuate cross section are in point contact with each other at substantially right angles. In addition, unlike the conventional metal brush, since the noble metal is not clad on the entire surface of the metal brush and only the convex portion is formed of the noble metal, the noble metal used can be reduced, so that the material cost can be reduced. Play.
[0028]
In addition to the effect of the invention described in claim 1, the invention described in claim 2 has an effect that the conductivity can be further improved. This is because a plurality of convex parts are arranged in parallel in the axial direction of the commutator, so that even if the motor brush vibrates due to the rotation of the motor, any convex part is in contact with the commutator. This is because it can be secured.
[0029]
The invention described in claim 3 has an effect that the material cost can be further reduced in addition to the effect of the invention described in claim 1 or claim 2. This is because the amount of expensive noble metal used can be further reduced because the first plating portion is formed by inexpensive metal plating and then precious metal plated thereon.
[0030]
The invention according to claim 4 has the effect of reducing the contact resistance and improving the conductivity with respect to the commutator. Moreover, there exists an effect that material cost can be reduced.
[0031]
According to the fifth aspect of the present invention, since the metal brush according to any one of the first to fourth aspects is used as a brush for a small motor, the conductivity with respect to the commutator can be improved and an inexpensive motor is provided. There is an effect that can be done.
[0032]
The invention according to claim 6 has an effect that the contact resistance is reduced to improve the conductivity with respect to the commutator, and the brush for the motor with reduced material cost can be manufactured.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a contact state between a metal brush and a commutator according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a metal brush according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating a manufacturing process of a metal brush according to an embodiment of the present invention.
FIG. 4 is a diagram illustrating a contact state between a conventional metal brush and a commutator.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Brush 2 for motors Convex part 2a 1st plating part 2b 2nd plating part 3 Commutator 4 Brush stand 5 Motor

Claims (6)

In a brush for a motor that supplies power to a commutator,
The brush body made of metal has the shape of "
In part of the brush body,
The convex portion having an arc-shaped cross section plated with a noble metal is characterized in that the axial direction of the convex portion is disposed substantially perpendicular to the axial direction of the commutator so as to contact the commutator. Brush for motor to be used.  The brush for a motor according to claim 1, wherein a plurality of the convex portions are arranged in parallel in the axial direction of the commutator.  3. The motor brush according to claim 1, wherein the convex portion includes a first plating portion and a second plating portion that covers the first plating portion. 4. In a brush for a motor that supplies power to a commutator,
The brush body made of metal has the shape of "
In part of the brush body,
The brush for motors provided with the convex part of the cross-section circular arc shape formed by noble metal plating so that it may contact with the said commutator.  The motor provided with the brush in any one of Claims 1 thru | or 4. In a method for manufacturing a brush for a motor,
A first step of performing resist printing of a slit pattern of a predetermined width on the plate material;
Applying a metal plating to the slit pattern, forming a convex portion having an arcuate cross section in contact with the commutator;
A third step of applying precious metal plating to cover the metal plating;
And a fourth step of punching the plate material into a predetermined brush shape.

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