JP2003018800A - Brush holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brush holder capable of suppressing an abnormal sound incident to a collision of the brush with a commutator. SOLUTION: A vibration damping hole 42 is formed on a left side wall 4L and a right side wall 4R respectively which functions as a vibration film actuated by the collision of the brush with a commutator, to decrease the area of both walls as much as an empty area of the hole 42; that is to say, the area to be vibrated caused by the collision of the brush is made smaller. Therefore, the vibration of the left and right walls 4L, 4R caused by the collision of the brush is suppressed, also the abnormal sound as well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brush holding device provided in a DC motor, and more particularly to a brush holding device that holds a brush for mechanically rectifying a power supply to a winding. .

[0002]

2. Description of the Related Art A brush holding device for a DC motor is fixed to a motor housing, is fixed to a substrate made of an insulating resin material, and is fixed to the substrate.
The brush holder is made of a metal material such as brass and has an opening on the commutator side. The brush holder accommodates a brush and a spring that biases the brush toward the commutator. As a result, in the DC motor, the commutator is rotated and the brush is brought into sliding contact with the commutator by the urging force of the spring to mechanically rectify the DC power from the outside and supply it to the winding.

[0003]

However, as the commutator rotates, the frictional force between the commutator and the brush fluctuates. As a result, when the brush vibrates and collides with the brush holder, abnormal noise is generated.

The present invention has been made in view of these problems, and an object thereof is to provide a brush holding device capable of suppressing abnormal noise caused by a collision of brushes. .

[0005]

In order to achieve the above object, according to the invention as set forth in claim 1, in a brush holding device for holding a brush and pressing it against the commutator, the brush is arranged in the rotating direction of the commutator with respect to the brush. On the side wall located,
A vibration suppression unit that suppresses vibrations caused by a brush collision is provided. Therefore, according to the first aspect of the invention, the vibrations due to the collision of the brush are suppressed by the vibration suppressing portion on the side wall located in the rotation direction of the commutator with respect to the brush.

According to a second aspect of the invention, in the brush holding device according to the first aspect, the vibration suppressing portion is a hole formed in the side wall. Therefore, according to the second aspect of the invention, the area of the side wall is reduced by the amount of the holes formed.
In other words, the area of the portion of the side wall that vibrates due to the collision of the brush becomes narrow. Therefore, the vibration of the side wall due to the collision of the brush is suppressed.

According to a third aspect of the present invention, in the brush holding device according to the first aspect, the vibration suppressing portion is an uneven structure formed on the surface of the side wall. Therefore, according to the third aspect of the present invention, the rigidity of the sidewall is increased by the uneven structure formed on the surface of the sidewall. Therefore, the side walls are less likely to vibrate as much as the rigidity is increased. As a result, vibration of the side wall due to the collision of the brush is suppressed.

According to a fourth aspect of the invention, in the brush holding device according to any one of the first to third aspects, the vibration suppressing portion is provided in the central portion of the side wall. Therefore, according to the fourth aspect of the present invention, the vibration suppressing portion provided at the central portion of the side wall, that is, the portion where the amplitude of the vibration caused by the collision of the brush is maximized causes the vibration of the side wall caused by the collision of the brush. Efficiently suppressed.

According to a fifth aspect of the invention, in the brush holding device according to any one of the first to fourth aspects, the vibration suppressing portion is provided closer to the side of the side wall where the brush collides than the central portion of the side wall. It was Therefore, according to the fifth aspect of the present invention, the vibration suppressing portion provided on the side where the brush collides with respect to the central portion of the side wall efficiently suppresses the vibration of the side wall due to the collision of the brush.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A first embodiment of the brush holding device according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of the brush holding device of the present embodiment, FIG. 2 is a side sectional view of the brush holding device, and FIG.
The exploded perspective view of a brush holding | maintenance apparatus is each shown in FIG.

As shown in FIG. 1, a brush holding device 1 for a DC motor comprises a substrate 2 and a brush holder 3.
The substrate 2 is made of an insulating resin material. The brush holder 3 is made of a metal material such as brass, which is excellent in heat resistance and has a small dimensional variation due to heat, and has a rectangular tube shape, and is fixed to the substrate 2.

As shown in FIG. 3, the brush holder 3 comprises a brush holder body 4 and a bottom plate 5. The brush holder body 4 has a U-shaped cross section and includes an upper wall 4U, a left side wall 4L and a right side wall 4R. A guide groove 41 is formed in the upper wall 4U from the commutator 6 side toward the anti-commutator 6 side. A pair of vibration suppressing holes 42 are formed in the left side wall 4L and the right side wall 4R. Bottom plate 5
Is a base 5 that closes the opening below the brush holder body 4.
D and a rising portion 5B for closing the opening of the brush holder body 4 on the side opposite to the commutator 6 are provided.

On the left side wall 4L and the right side wall 4R of the brush holder body 4, a pair of fixing pieces 43 are formed so as to extend downward from the center of the lower end. Each of these fixing pieces 43 is inserted into a pair of engaging recesses 51 formed in the base portion 5D of the bottom plate 5 and a pair of fitting holes 21 formed in the substrate 2, and is bent inward. As a result, as shown in FIG. 2, the brush holder body 4 and the bottom plate 5 are integrally fixed to the substrate 2.
Then, in the fixed state, the brush holder body 4
The accommodation section S is formed so that only the commutator 6 side is opened.

The accommodating portion S accommodates a brush 7 and a spring 8 for urging the brush 7 toward the commutator 6 side. As a result, the brush 7 is brought into sliding contact with the commutator 6 by the urging force of the spring 8 and mechanically rectifies the DC power supplied from above the brush holder 3 via the pigtail 9 and supplies it to the winding.

By the way, when the commutator 6 is rotated when the power is rectified in this way, the commutator 6 is rotated.
The frictional force between the commutator 6 and the brush 7 varies with the rotation of the. As a result, the brush 7 vibrates and the left side wall 4L
Or, when it collides with the right side wall 4R, abnormal noise is generated. The abnormal noise increases as the area of the left side wall 4L or the right side wall 4R that acts as a vibrating film with the collision of the brush 7 increases.

Therefore, in the present embodiment, in order to suppress the abnormal noise due to the collision of the brush 7, the left side wall 4L and the right side wall 4
The area of R is narrowed. That is, the pair of vibration suppressing holes 42 are formed in the left side wall 4L and the right side wall 4R.

Next, the vibration suppressing hole 42 will be described with reference to FIG.
Will be explained. As shown in FIG. 4, the vibration suppressing hole 42
Is composed of a first suppressing portion 42a and a second suppressing portion 42b. The first suppressing portion 42a is formed at the central portion of the left side wall 4L or the right side wall 4R, that is, at the portion where the amplitude of vibration associated with the collision of the brush 7 is maximized. 2nd suppression part 4
2b is on the side where the brush 7 collides with the left wall 4L or the right wall 4R in the center, that is, when the brush 7 vibrates with the connection portion with the pigtail 9 as a fulcrum, the left wall 4L.
Alternatively, it is formed below the right side wall 4R.

As described above in detail, according to this embodiment, the following actions and effects can be obtained. (1) The vibration suppressing holes 42 are formed in the left side wall 4L and the right side wall 4R that act as a vibrating film when the brush 7 collides, and the vibration suppressing holes 42 form the areas of the left side wall 4L and the right side wall 4R. It's made as narrow as it was done. In other words,
In the left side wall 4L and the right side wall 4R, the areas of the portions that vibrate with the collision of the brush 7 are narrowed. for that reason,
Vibration of the left side wall 4L and the right side wall 4R due to the collision of the brush 7 is suppressed. Therefore, it is possible to suppress the abnormal noise caused by the collision of the brushes 7.

(2) The vibration suppressing hole 42 is formed in the first suppressing portion 42a.
And the second suppressing portion 42b. And the first
The suppressing portion 42a is provided at the central portion of the left side wall 4L or the right side wall 4R,
That is, it is formed in a portion where the amplitude of vibration associated with the collision of the brush 7 is maximized. Therefore, the first suppressing unit 42
The vibration of the left side wall 4L and the right side wall 4R due to the collision of the brush 7 is efficiently suppressed by a. Therefore, the brush 7
It is possible to reliably suppress the abnormal noise that accompanies the collision.

(3) In addition, the second suppressing portion 42b vibrates on the side where the brush 7 collides with the central portion of the left side wall 4L or the right side wall 4R, that is, the brush 7 uses the connecting portion with the pigtail 9 as a fulcrum. In the case, the left side wall 4L or the right side wall 4
It is formed under R. Therefore, the second suppressing unit 4
The vibration of the left side wall 4L and the right side wall 4R due to the collision of the brush 7 is efficiently suppressed by the 2b. Therefore, it is possible to reliably suppress the abnormal noise caused by the collision of the brushes 7.

(4) When the commutator 6 rotates in the clockwise direction shown by the arrow CW in FIG. 1, the brush 7 easily collides with the right side wall 4R as the commutator 6 rotates. On the other hand, when the commutator 6 rotates counterclockwise, the brush 7 is likely to collide with the left side wall 4L as the commutator 6 rotates. That is, when the commutator 6 rotates bidirectionally like a DC motor used in a power steering device of an automobile, the brush 7 is attached to either the left side wall 4L or the right side wall 4R as the commutator 6 rotates. Is also likely to collide. Therefore, in the present embodiment, the vibration suppression holes 4 are formed in both the left side wall 4L and the right side wall 4R.
Forming 2. Therefore, even when the commutator 6 rotates bidirectionally, it is possible to suppress the abnormal noise caused by the collision of the brushes 7.

(Second Embodiment) Next, a second embodiment of the present invention will be described. The second embodiment is mainly different from the first embodiment in that the vibration suppressing hole 42 is formed by flange forming, so-called burring. This flange forming refers to a forming process in which a die is pressed into a hole to form a flange around the hole of the metal plate.

That is, as shown in FIG. 5, the left side wall 4L and the right side wall 4R are each formed with a vibration suppressing hole 42 whose diameter decreases outward, and a flange F is formed around the vibration suppressing hole 42. Are formed.

As described above in detail, according to this embodiment, the following actions and effects can be obtained. (5) The vibration suppressing hole 42 is formed by flange molding,
A flange F is formed around the vibration suppressing hole 42. Therefore, the flange F enhances the rigidity of the left side wall 4L and the right side wall 4R, and compensates for the rigidity of the left side wall 4L and the right side wall 4R which is reduced due to the formation of the vibration suppressing hole 42. Therefore, the left side wall 4 is formed by the formation of the vibration suppressing hole 42.
It is possible to suppress the decrease in the rigidity of L and the right side wall 4R as much as possible.

(Third Embodiment) Next, a third embodiment of the present invention will be described. The third embodiment is mainly different from the first embodiment in that, instead of forming the vibration suppressing holes 42 in the left side wall 4L and the right side wall 4R, uneven portions are formed on the inner surfaces of the left side wall 4L and the right side wall 4R. This is the point where 44 is formed.

That is, as shown in FIG. 6, an uneven portion 44 is formed on the inner surfaces of the left side wall 4L and the right side wall 4R.
The uneven portion 44 includes the first suppressing portion 44a and the second suppressing portion 44b.
It consists of The first suppressing portion 44a includes the left side wall 4L.
Alternatively, it is formed in the central portion of the right side wall 4R, that is, in the portion where the amplitude of vibration associated with the collision of the brush 7 is maximized. The second suppressing portion 44b is a side where the brush 7 collides with respect to the center portion of the left side wall 4L or the right side wall 4R, that is, when the brush 7 vibrates with the connection portion with the pigtail 9 as a fulcrum,
It is formed below the left side wall 4L or the right side wall 4R.

The uneven portion 44 is formed on the left side wall 4L and the right side wall 4
Instead of the configuration formed on the inner surface of R, the configuration may be formed on the outer surfaces of the left side wall 4L and the right side wall 4R. Also in this case, the same operation and effect as described below can be obtained.

As described above in detail, according to this embodiment, the following actions and effects can be obtained. (6) The uneven portion 44 is formed on the inner surfaces of the left side wall 4L and the right side wall 4R that act as a vibrating film when the brush 7 collides, and the uneven portion 44 causes the left side wall 4L and the right side wall 4R.
The rigidity of is improved. Therefore, the left side wall 4L and the right side wall 4R are less likely to vibrate due to the increased rigidity. As a result, the left side wall 4L and the right side wall 4R accompanying the collision of the brush 7
Vibration is suppressed. Therefore, it is possible to suppress the abnormal noise caused by the collision of the brushes 7.

(7) In addition, since the vibration energy is attenuated by the uneven portion 44, the vibration of the left side wall 4L and the right side wall 4R due to the collision of the brush 7 is suppressed, so that the difference due to the collision of the brush 7 is suppressed. The sound can be reliably suppressed.

The above-mentioned respective embodiments can be modified and embodied as follows. -In each said embodiment, although the vibration suppression hole 42 or the uneven part 44 was formed in both the left side wall 4L and the right side wall 4R, the vibration suppression hole 42 is formed in either the left side wall 4L or the right side wall 4R.
Alternatively, the uneven portion 44 may be formed. Specifically, when the commutator 6 rotates only in the clockwise direction indicated by the arrow CW in FIG. 1, the brush 7 easily collides with the right side wall 4R as the commutator 6 rotates. Therefore, only the right side wall 4R is provided with the vibration suppressing hole 42 or the uneven portion 4
4 is formed. On the other hand, when the commutator 6 rotates counterclockwise, the brush 7 is likely to collide with the left side wall 4L as the commutator 6 rotates. Therefore, the vibration suppressing hole 42 or the uneven portion 44 is formed only on the left side wall 4L.

In the first embodiment or the second embodiment, the single vibration suppressing hole 42 is formed in each of the left side wall 4L and the right side wall 4R, but at least one of the left side wall 4L and the right side wall 4R is formed. Alternatively, a plurality of small holes may be formed as a vibration suppressing portion on one side.

Further, the technical idea grasped from the above embodiment will be described below together with their effects. [1] The brush holding device according to claim 2, wherein the vibration suppressing portion is a hole formed by flange molding. According to this structure, a flange is formed on the side wall by flange molding. Therefore, the flange enhances the rigidity of the side wall and compensates for the rigidity of the side wall which is lowered due to the formation of the hole. Therefore, it is possible to suppress deterioration of the rigidity of the side wall due to the formation of the hole as much as possible.

[0033]

Since the present invention is constructed as described above, it has the following effects. According to the invention described in any one of claims 1 to 5, it is possible to suppress the abnormal noise caused by the collision of the brushes.

[Brief description of drawings]

FIG. 1 is a perspective view of a brush holding device according to a first embodiment.

FIG. 2 is a side sectional view of the brush holding device according to the first embodiment.

FIG. 3 is an exploded perspective view of the brush holding device according to the first embodiment.

FIG. 4 is a side view of the brush holder body according to the first embodiment.

FIG. 5 is a perspective view of a brush holder body according to a second embodiment.

FIG. 6 is a partial cross-sectional perspective view of a brush holder body according to a third embodiment.

[Explanation of symbols]

1 ... Brush holding device, 4L ... Left side wall as side wall, 4R
... right side wall as side wall, 6 ... commutator, 7 ... brush, 42 ... vibration suppressing hole as vibration suppressing portion, 44 ... uneven portion as vibration suppressing portion.

Claims (5)

[Claims] 1. A brush holding device for holding a brush and pressing it against a commutator, wherein a side wall located in the rotation direction of the commutator with respect to the brush is provided with a vibration suppressing portion for suppressing vibration due to collision of the brush. apparatus. 2. The brush holding device according to claim 1, wherein the vibration suppressing portion is a hole formed in a side wall. 3. The brush holding device according to claim 1, wherein the vibration suppressing portion has an uneven structure formed on a surface of a side wall. 4. The brush holding device according to claim 1, wherein the vibration suppressing portion is provided in a central portion of a side wall. 5. The brush holding device according to any one of claims 1 to 4, wherein the vibration suppressing portion is provided closer to the side of the side wall where the brush collides than the central portion of the side wall.