JP3317838B2 - Brush holder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an electric motor or
The present invention relates to a brush holder for holding a carbon brush for energizing a commutator of a generator.

[0002]

2. Description of the Related Art A brush holder as shown in FIG. 9 is conventionally known (Japanese Utility Model Publication No. 44-20417). As shown in FIG. 9 , the brush holder is provided with a synthetic resin insulating cylinder 91 fixed in a frame 90 on the stator side of the electric motor. In the insulating cylinder 91, a brush holding cylinder 92 cut out from a brass material is held with its lower part protruding from the lower surface of the insulating cylinder 91. A carbon brush 93 is accommodated in the brush holding tube 92 with its tip protruding from the lower surface of the brush holding tube 92. The brush holding cylinder 92 is integrally molded by insert molding when the insulating cylinder 91 is molded.

A conductive wire 9 is provided at the rear of the carbon brush 93.
4, one end of the conductive wire 94 is connected to the other end of the conductive wire 94.
It is connected to a metal spring receiver 95 attached to the upper surface of the brush holding cylinder 92. An elastic pressure spring 96 is accommodated between the spring receiver 95 and the carbon brush 93, and the tip of the carbon brush 93 contacts the surface of the commutator 97 with a constant pressure by the urging force of the elastic pressure spring 96. Is done. A cap 98 for fixing the spring receiver 95 to the upper end of the brush holding cylinder is screwed and fixed to the upper part of the insulating cylinder 91, whereby the biasing state of the elastic pressure spring 96 is maintained, and the spring receiver 95 and the brush are fixed. The continuity with the holding cylinder 92 is maintained. Also, on the lower peripheral surface of the brush holding cylinder 92,
A power supply connection spring (garter spring) 99 connected to the stator side is fitted therein.

In the above-mentioned brush holder, since the brush holding cylinder 92 is formed by cutting out a brass material, manufacturing costs are increased. In particular, since it is necessary to ensure a sufficient current-carrying capacity between the spring receiver 95 and the brush holding cylinder 92, the contact area between the spring receiver 95 and the brush holding cylinder 92 must be increased. Therefore, since the thickness of the brush holding cylinder 92 is increased, the material cost is increased. In order to reduce the cost, a brush holding cylinder manufactured by bending a brass plate-like member as shown in FIG. 10 has been proposed (Japanese Utility Model Publication No. 3-23823). The brush holding cylinder 110 is formed with arc-shaped tongues 114 and 114 having a concave portion 112 for fitting the connection spring 99 used in the brush holding cylinder 92 described above. The diameter of the circle drawn by the recess 112 is the same as the diameter of the lower part of the brush holding tube 92 in order to ensure compatibility with the connection spring 99 used in the brush holding tube 92.

[0005]

However, in the case of the latter conventional one, as shown in FIG.
Since the gaps 116, 116 are formed between the tongues 114, when the connection spring 99 is fitted to the peripheral surface of the tongue piece 114, the connection spring 99 has a shape shown by a two-dot chain line in FIG. In other words, the arc-shaped portion 10 in contact with the peripheral surface of the tongue piece 114
0 and the linear portion 10 of the portion bridged over the gap 116
2 and the circumference of the connection spring 99 is shorter than that of a circular shape. Therefore, the linear portion 10
2, the tightening force of the connection spring 99 against the tongue piece 114 is reduced, so that there is a problem that the connection spring 99 is easily detached by the vibration of the electric motor.

Moreover, the connecting spring 99 is in sharp contact with the corner 118 of the cut end of the tongue piece 114, and the connecting spring 99 rubs against the corner 118 due to the vibration of the electric motor. There is also a problem that is disconnected. That is, in the above-described conventional device, there is a possibility that power supply to the brush may not be possible due to disconnection or disconnection of the connection spring 99.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to prevent the connection spring for power supply from coming off or being cut off so that the power supply to the brush is prevented. Is to stabilize.

[0008]

According to the first aspect of the present invention, there is provided an insulating tube (80) formed of an insulating material and having a cylindrical shape. 80) a brush holder (10), which is formed in a tubular shape by bending a conductive plate-like member,
A brush holder provided with the carbon brush (40) held in the brush holder fitting (10), wherein the brush holder fitting (10) has a peripheral surface (1).
8, 24), and an arc-shaped winding member (30 to 33) into which a garter spring (99) for power supply is fitted, and the winding member (30 to 3).
3) is provided on the peripheral surface (36, 37) of the brush holder fitting (10) that appears in the gap (38, 39) formed between the circumferential ends (30b to 33b);
Projections (34, 3) projecting into the gaps (38, 39)
5) is adopted.

According to a second aspect of the present invention, in the brush holder according to the first aspect, the protrusions (34, 35) are provided.
Adopts the technical means that the garter spring (99) is protruded to a height that maintains the circular shape. The reference numerals in the parentheses correspond to the reference numerals in the embodiments of the invention described later.

[0010]

According to the first or second aspect of the invention, the peripheral surface of the bracket for the brush holder, which appears in the gap formed between the circumferential ends of the winding member, protrudes into the gap. Since the protrusion is provided, the portion of the garter spring located in the gap can be brought into contact with the protrusion when the garter spring is fitted into the winding member. That is, the deformation of the garter spring fitted into the winding member can be reduced.

[0011] Therefore, since a tightening force can be generated for the brush holder at the portion of the garter spring located in the gap, the garter spring can be prevented from coming off. Moreover, since the garter spring is lifted up from the end by the protruding portion, the force with which the garter spring rubs against the end of the winding member can be reduced. Cutting can be prevented.

Particularly, as in the second aspect of the present invention, the projecting portion is projected to a height which maintains the garter spring in a circular shape, so that the tightening force of the garter spring against the metal fitting for the brush holder is evenly distributed. It is desirable in doing.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an explanatory longitudinal sectional view showing a brush holder of the present embodiment, and FIG.
FIG. 3 is an explanatory view showing a contact portion between a connection fitting and a locking piece used in the brush holder shown in FIG. 3, FIG. 3 is a plan explanatory view of the insulating cylinder shown in FIG. 1 and FIG. 2, and FIG. FIG. 5 is an external perspective view of a brush holder bracket and a carbon brush constituting the brush holder shown in FIG. 5, FIG. 5 is an external perspective view of the brush holder bracket and garter spring shown in FIG. 1, and FIG. 6 is a brush holder shown in FIG. 7 is a front view of FIG. 6, and FIG. 8 is an exploded view of the brush holder shown in FIGS. 4 to 7. FIG. In the present embodiment,
A brush holder used for an AC motor typified by an electric tool will be described as an example.

First, the main configuration of the brush holder according to the present embodiment will be described with reference to FIG. As shown in FIG. 1, the brush holder is provided with a synthetic resin insulating tube 80 embedded in the housing of the AC motor. A female screw 84 is formed on the inner peripheral surface at the upper end of the insulating cylinder 80, and a stepped portion 82 is further provided from the female screw 84 to form a hole 8.
1 is formed. In addition, the brush holder fitting 10 described later in detail is inserted into the hole 81.

As shown in FIG. 2, a bracket 1 for a brush holder
Locking pieces 22, 23, 28, and 29 are formed by bending at the periphery of the upper end of the hole 0, respectively.
It is locked by one step portion 82. These locking pieces 22,
A peripheral portion 63 of a connection fitting 60 indicated by a dotted line
However, the upper surface of the locking pieces 28 and 29 are in contact with the peripheral edge 62, respectively.

As shown in FIG. 1, a connection fitting 60 made of a conductive material has a pigtail (conductive wire) 50 made of copper.
Is connected to the other end 51 of the pigtail 50, and the brush 40a is connected to the other end 51 of the pigtail 50. Brush 4
A coil spring (spring member) 70 is interposed between Oa and the connection fitting 60 to form the carbon brush 40. A garter spring 99 for power supply (see FIGS. 5 to 7) is fitted on the lower peripheral surface of the brush holder fitting 10.

A cap 98 is screwed into and fixed to the female screw 84 on the inner peripheral surface of the upper portion of the insulating cylinder 80. The cap 98 presses the connection fitting 60, and the peripheral portion 6 is pressed.
The conduction state between 2, 63 and the locking pieces 22, 23, 28, 29 is maintained.

The connection fitting 60 is formed with a flat plate member 61 to which the other end 52 of the pigtail 50 is connected. The flat plate member 61 has an arc-shaped peripheral portion 6 on the opposing peripheral edges.
2 and 63 are formed in an elliptical shape.
Plate members 66, 67 orthogonal to the lower surface of the flat plate member 61 are formed integrally with the straight portions 64, 65 between the plates 2, 63. In FIG. 4, the connection fitting 60 is drawn in the illustrated direction for convenience of description, but actually, as described in the description of the assembly of the carbon brush 40 described later, a brush holder When inserting from the other end 12 of the metal fitting 10, 90
And the plate-like members 66 and 67 are inserted into the brush holder metal fitting 10 along the peripheral edges 14 and 15 thereof.

Next, the structure of the brush holder fitting 10 will be described with reference to FIGS. The brush holder fitting 10 is formed by pressing a brass plate-like member (see FIG. 8) formed by punching out the brush holder fitting 10 into a developed shape by press working, and has one end 11 and the other end. Are formed in the shape of a tube, each of which has an open end. Openings at both ends 11 and 12 have U-shaped peripheral edges 14 and 15 corresponding to the outer peripheral shape of the brush 40a.
And arc-shaped peripheral edges 16 and 17 corresponding to the outer peripheral shape of the coil spring 70.

Arc-shaped peripheral surface 1 of brush holder fitting 10
8 are the joint pieces 1 joined to each other at the time of bending and forming.
9 and 20 are formed, and a plurality of caulked portions 21 are provided on these joining pieces 19 and 20. On the extension of the joining pieces 19, 20, arc-shaped (crescent-shaped) locking pieces 22, 23 are integrally formed with their respective ends facing the opening of the other end 12. Locking piece 22
Can be bent in a direction indicated by an arrow in the figure and formed at a virtual position indicated by a two-dot chain line in the figure.
Can be bent in the direction opposite to the locking piece 22 and formed at a position symmetrical to the locking piece 22 (see FIG. 2).

As shown in FIG. 5, joint pieces 25 and 26 similar to the joint pieces 19 and 20 are also formed on a peripheral surface 24 symmetrical to the peripheral surface 18.
On the extension of 5, 26, locking pieces 28, 29 symmetrical to the locking pieces 22, 23 are integrally formed so as to face the opening of the other end 12, respectively. The locking piece 28 can also be bent in the direction indicated by the arrow in the figure and formed at a virtual position indicated by the two-dot chain line in the figure.
Can be formed in a position symmetrical to the locking piece 28 by bending in the opposite direction (see FIG. 2).

As shown in FIGS. 4 and 5, on the peripheral surface on the one end 11 side of the brush holder fitting 10, there is provided a housing groove 30a through which a power supply garter spring 99 (see FIG. 5) is fitted. The arc-shaped winding members 30 to 33 on which the receiving grooves 33a are formed are bent.
7, 0a to 33a are formed in a semicircular cross section corresponding to the outer peripheral shape of the garter spring 99, as shown in FIG. Opposing gaps 38, 39 are formed between the circumferential ends 30b and 32b and 31b and 33b of the winding members 30 to 33, and brushes appearing (visible) in the gaps 38, 39. Projections 34 and 35 having a substantially trapezoidal cross section are formed on the peripheral surfaces 36 and 37 of the holder fitting 10 in a planar shape, respectively (FIG. 4).
Or FIG. 7).

These protruding portions 34 and 35 are formed by pressing a plate-like member shown in FIG. 8 to form a circle drawn by the outer periphery of the winding members 30 to 33 as shown in FIG. The contact height, that is, the garter spring 99 wound around the winding members 30 to 33
Is formed to have a height that maintains a circular shape (substantially perfect circle). Further, as shown in FIG. 1, the winding members 30 to 33 are provided at lower end surfaces 8 of holes 81 formed at the lower end of the insulating cylinder 80.
6 to prevent the brush holder fitting 10 from coming off from the upper end of the insulating cylinder 80.

The projecting portions 34 and 35 are provided with a garter spring 99 wound around the winding members 30 to 33.
Is most preferably formed to have a height that makes it circular. However, it is desirable that the height be at least equal to or higher than the height at which the gaps 38 and 39 contact the garter spring 99. In other words, in order to reduce the force with which the garter spring 99 contacts the ends 30b to 33b of the winding member, the gaps 38, 3
The garter spring 99 is desirably formed to have a height equal to or higher than the height capable of lifting the garter spring 99 by protruding into the inner surface 9.

As described above, according to the brush holder of the present embodiment, the garter spring 99 is in contact with the protrusions 34 and 35 at the portions located in the gaps 38 and 39 between the winding members 30 to 33. The tightening force on the brush holder fittings is
Does not weaken. Therefore, it is possible to prevent the garter spring 99 from coming off the accommodation groove 30a or 33a. Moreover, since the corners of the ends 30b to 33b of the winding members 30 to 33 can be prevented from contacting the garter spring 99, the vibration of the electric motor is transmitted to the garter spring 99 and Rubbing and cutting at the corners can also be prevented.

Next, the assembly of the carbon brush 40 and the brush holder fitting 10 will be described. First, the other end 12 of the brush holder fitting 10 is inserted into the hole 81 from the lower surface of the insulating cylinder 80. And the peripheral edge 14 of the other end 12
When 17 to 17 reach the peripheral position of the hole 81, the locking pieces 22, 23, 28 and 29 of the brush holder metal fitting 10 are bent to the predetermined positions, respectively, and the locking pieces are
(See FIG. 2).

Next, the above-mentioned components are press-fitted into the housing of the electric motor, and the garter spring 99 is fitted into the winding members 30 to 33. Then, the brush 40a is inserted along the peripheral edges 14 and 15 of the one end 12 of the brush holder fitting 10, and the coil spring 70 is passed through the peripheral edges 16 and 1.
Insert along 7. Then, when the plate-like members 66 and 67 of the connection fitting 60 are inserted along the peripheral edges 14 and 15, respectively, the peripheral edge 62 of the connection fitting 60 is locked with the locking pieces 22 and 2.
The peripheral portion 63 is in contact with the upper surfaces of the locking pieces 28 and 29. Next, the female screw 8 of the insulating cylinder 80
4 is screwed and fixed with a cap 98.

The locking pieces 22, 23, 28, 29 of the brush holder fitting 10 of the brush holder thus assembled.
FIG. 2 shows a contact portion between the contact member and the connection fitting 60 by oblique lines. As shown in the drawing, substantially the entire upper surface of each of the locking pieces 22, 23, 28, and 29 is a contact portion, and it is necessary to secure a large contact area as in the conventional device shown in FIG. Can be. Therefore, since the heat generation amount can be reduced by sufficiently securing the conduction capacity at the contact portion, the brush holder can be prevented from being damaged by the melting or thermal expansion of the insulating cylinder 80. Further, the present invention can be suitably applied to a DC motor, a DC generator, an AC generator, and the like.

[0029]

As described above, according to the brush holder of the present invention, it is possible to prevent the power supply gutter spring, which is fitted into the brush holder for holding the brush, from coming off the housing groove and being cut off. Power can be stabilized.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view showing a brush holder according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a contact portion between a connection fitting used in the brush holder shown in FIG. 1 and a locking piece.

FIG. 3 is an explanatory plan view of the insulating cylinder shown in FIGS. 1 and 2;

FIG. 4 is an external perspective explanatory view of a brush holder fitting and a carbon brush which constitute the brush holder shown in FIGS. 1 and 2;

FIG. 5 is an external perspective explanatory view of a brush holder fitting and a garter spring shown in FIG. 1;

6 is an explanatory bottom view showing a state in which a garter spring is attached to the brush holder fitting shown in FIG. 5;

FIG. 7 is an explanatory front view of FIG. 6;

FIG. 8 is a development explanatory view of the brush holder bracket shown in FIGS. 4 to 7;

FIG. 9 is an explanatory vertical sectional view of a conventional brush holder.

FIG. 10 is an explanatory perspective view of the appearance of a conventional brush holding cylinder.

11 is an explanatory plan view showing a state where a garter spring is attached to the brush holding cylinder shown in FIG. 10;

[Explanation of symbols]

 Reference Signs List 10 Brush holder bracket 18, 24 Peripheral surface 30 to 33 Winding member 34, 35 Projecting portion 36, 37 Peripheral surface 40 Carbon brush 40a Brush 50 Pigtail 60 Connection metal fitting 70 Coil spring 80 Insulation cylinder 99 Garter spring

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02K 13/00-13/14 H02K 5/00-5/26 H01R 39/00-39/64

Claims (2)

(57) [Claims] 1. An insulating tube formed of an insulating material in a tubular shape, a brush holder which is housed in the insulating tube, and is formed by folding a conductive plate-like member into a tubular shape. A brush holder provided with a carbon brush held in a brush holder fitting, wherein the brush holder fitting is formed along a peripheral surface thereof, and has an arc shape into which a power supply garter spring is fitted. And a projection provided on a peripheral surface of the brush holder fitting, which appears in a gap formed between circumferential ends of the winding member, and protruding into the gap. A brush holder, characterized in that: 2. The brush holder according to claim 1, wherein the protrusion is protruded to a height that maintains the garter spring in a circular shape.