JPH08223870A - Feeding brush of small dc motor - Google Patents

Abstract

PURPOSE: To obtain large warpage for a brush of a small DC motor in which a space for providing brushes is not large enough. CONSTITUTION: In a small DC motor, one end of a feeding brush is brought into sliding contact with a commutator and the other end is fixed to a brush base. One cut trench 2 is formed in the middle part of the brush B which is formed into a plate-shape so as to bring into contact with the commutator by a switch-back system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a power supply brush for a small direct current motor, and particularly for a small direct current motor in which the brush arrangement space cannot be set large.

[0002]

2. Description of the Related Art Conventionally, a DC motor having a plate-shaped power feeding brush having one free end slidably contacting a commutator and the other end fixed to a brush base is widely known. Such a power feeding brush is formed straight from the base end to the free end, or the middle portion is bent into a face-to-face L-shape for miniaturization to obtain a large amount of deflection.

[0003]

However, even if the power feeding brush having such a structure can be used for a relatively large DC motor, the cylindrical motor has a diameter of 6 mm or less, or the magnet has an inner diameter of 6 mm. If the flat motor below is one that requires the brush itself to fit within the inner diameter of the magnet, it is difficult to secure the amount of deflection, and if the plate brush made of precious metal reaches a thickness of about 0.05 mm. However, it had a problem that it was easily deformed. Further, in the case of bending the surface-opposing L-shape at an acute angle, the noble metal brush made of a spring material has a problem of breakage.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a power feeding brush which can be used in a DC motor which does not require a large space for disposing the brush so as to have a large amount of deflection. Is.

[0005]

According to the invention as set forth in claim 1, the above object is to provide a DC motor power supply brush having one end slidably contacting a commutator and the other end fixed to a brush base. It is possible to achieve this by forming it and making at least one notch in the middle and slidingly contacting the commutator in a switchback system. More specifically, as in the invention as set forth in claim 2, the commutator is formed in a flat plate type, and the brush slidingly contacting the flat plate type commutator is such that at least the sliding contact portion is concentric with the shaft, and the sliding contact is made. This can be achieved by forming the portion so as to be arranged on the inner diameter side. Furthermore, as in the invention described in claim 3, the base portion of the brush is integrally connected, and the brush can be achieved by implanting the brush base and then cutting off the connecting portion to form a pair. Further, according to the invention as set forth in claim 4, it can be achieved by connecting the brush to a terminal arranged on the brush base and then cutting the brush together with the terminal. According to a fifth aspect of the present invention, the commutator is formed in a cylindrical shape, and a brush slidingly contacting the cylindrical commutator has a sliding contact portion on a rotor side and at least a part of a base end is a side surface. It can also be achieved by arranging the sliding contact portion at the position.

[0006]

According to the above means for achieving the above object, the substantial length of the brush can be made large, and the amount of deflection can be made large. Therefore, it is possible to reduce variations in the pressure of sliding contact with the commutator. According to the above means for achieving the above object, the sliding contact portion of the brush is concentric with the shaft, and the sliding contact portion of the brush has a small diameter, so that the braking loss is reduced. According to the above-mentioned means for achieving the above-mentioned object, since the pair of brushes are connected at the base portion, the position becomes constant when the brush is planted in the brush base, and the brush is cut off after the planting. It becomes a power feeding brush with a fixed position. According to the above-mentioned means for achieving the above-mentioned object, the brush base having the terminal has the same function as described above. According to the above means for achieving the above object, a cylindrical commutator can be effectively used by utilizing the private space.

[0007]

[First Embodiment] FIG. 1 is a plan view of a plate brush which is in sliding contact with a flat plate commutator in the axial direction, that is, an axial sliding contact type plate brush B as a first embodiment showing the feature of the present invention. Are integrally connected to the base 1, and spot welded to the terminals T on both sides of the base 1. The movable part is provided with one notch groove 2 in the middle, and the two sliding contact parts 3 are arranged on the inside so as to be concentric with the shaft and the movable spring part 4 is provided on the outside. Has been formed. The sliding contact 3a of the sliding contact portion 3 is equal to the magnetized opening angle,
In this case, it is set to 90 °. After the press-cutting process of the brush B having such a shape, as shown in FIG. 2 which shows a cross section of a main part of a flat motor using the brush, the brush B is slidably brought into contact with the flat plate commutator F at a folding back point 5 in a switchback manner. It is made by bending. In the figure, b is a brush base in which a terminal T is planted, which is integrally molded with the terminal T on a metal end bracket 7. In order to pair the plate brushes B in the forward and reverse directions, the connected base portions 1 may be spot-welded to the terminals T on both sides and then cut together with the terminals T by a press at a position indicated by a broken line. Reference numeral 8 is a die-shaped hole formed in the cut portion.

In this way, at the turning point 5, since the structure is not such that it is bent so as to be face-to-face with a rounded shape, the structure of the mold is simple, and the reserved space can be reduced, and the space between the base of the brush B and the flat plate commutator F is extremely small. Even if it is a thing, there is no possibility that the turning point will come into contact with the flat plate commutator first. Further, since the sliding contact portion 3 is arranged concentrically with the shaft and is located inside, the braking loss can be reduced. Reference numeral 9 is a magnet mounted on the bracket 7, and 10 is a rotor integrated with the flat plate commutator. Further, H indicates a housing for housing this.

[0009]

[Second Embodiment] FIG. 3 is a plan view of a cylindrical commutator as a second embodiment of the present invention when it is arranged so as to be in sliding contact with the cylindrical commutator from the radial direction, and FIG. FIG. 3 is a side view of the main part of a part of the brush seen from one direction. That is, the radial sliding contact type plate brush V is spot welded at the base end 11 to the terminals t and t which are planted in the brush base 66 so as to face each other by 180 ° with the cylindrical commutator C arranged at the center therebetween. The movable portion is inserted into the cut groove 22 and returns to the switchback system at the intermediate turning point 55 and is slidably contacted to the commutator C with an appropriate pressure. Therefore, this sliding contact portion is above the movable portion (rotor side). The terminal portion is provided so as to come to the position of the sliding contact portion when viewed from the side surface. Even in this case, since the folding point 55 does not have a structure of bending in a face-to-face relationship with a roundness, the structure of the mold can be simplified, and the arrangement of the terminal t is particularly well utilized, so that the brush occupying space can be increased. No need to take.

[0010]

As described above, according to the present invention, the amount of deflection can be made large even when the arrangement space of the brush is restricted, so that the variation in the pressure of sliding contact with the commutator can be reduced, and moreover, the sharpness can be achieved in the face-to-face relationship. Even if it is a hard spring material, it does not bend into an L shape
This has the advantage of preventing breakage and simplifying the mold structure.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of a power supply brush of a DC motor according to the present invention.

FIG. 2 is a side view of the main part of the same.

FIG. 3 is a plan view of an essential part of another embodiment of the present invention.

FIG. 4 is a side view of an essential part of a partial cross section of FIG.

[Explanation of symbols]

 B Axial sliding contact type plate brush 1 Base T terminal 2 Notch groove 3 Sliding contact part 4 Movable spring part 5 Folding point F Flat plate commutator V Radial sliding contact type plate brush C Cylindrical commutator 11 Base end 55 Folding point t Terminal

Claims (5)

[Claims] 1. A switchback system in which a brush is formed in a plate shape and at least one cut is made in the middle of a power supply brush of a small direct current motor having one end slidably contacting a commutator and the other end fixed to a brush base. A power supply brush for a small DC motor that comes into sliding contact with a commutator. 2. The commutator is formed in a flat plate type, and the brush slidingly contacting the flat plate type commutator is formed so that at least the sliding contact portion is concentric with the shaft and the sliding contact portion is arranged on the inner diameter side. The power supply brush for the small DC motor according to claim 1. 3. The power supply brush for a small direct current motor according to claim 2, wherein the brushes are integrally connected at their bases, and after being planted in the brush base, the connection is cut off to form a pair. 4. The power supply brush for a small DC motor according to claim 3, wherein the brush is connected to a terminal arranged on the brush base and then cut at the connecting portion together with the terminal. 5. The commutator is formed in a cylindrical shape, and a brush slidingly contacting the cylindrical commutator has a sliding contact portion on the rotor side, and at least a part of a base end of the brush is the sliding contact portion. The power supply brush for a small direct current motor according to claim 1, wherein the power supply brush is located at the position.