JP3668671B2 - Brush holding frame for electric motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of a brush holding device for an electric motor used for a DC electric motor.
[0002]
[Prior art]
FIGS. 11 to 19 are views showing a conventional brush holding device for an electric motor disclosed in, for example, Japanese Patent Laid-Open No. 11-275817. First, the brush holding device is shown in a plan view of FIG. 11 and the brush holding frame of FIG. This will be described with reference to a sectional view. In the figure, reference numeral 21 denotes a brush whose tip is in contact with the commutator of the electric motor, 22 is a brush holding frame formed of a synthetic resin having high insulating properties, and 23 guides a current from or to the brush 21. It is a flexible conductive member also called a pigtail, and this flexible conductive member 23 is led out from a lead-out hole 24 provided on the side surface of the brush holding frame 22. Reference numeral 25 denotes a substrate to which the brush holding frame 22 is assembled and fixed. In this brush holding device, four brush holding frames 22 are annularly arranged on the substrate surface of the substrate 25 with the tip of the brush 21 facing the center of the substrate 25, and the lower portions on both sides of each brush holding frame 22 are fixed to the substrate 25, respectively. Has been.
[0003]
Next, fixing means for assembling and fixing the brush holding frame 22 to the substrate 25 will be described with reference to FIGS. 13 is a front view of the brush holding frame, FIG. 14 is a plan view thereof, and FIG. 15 is a right side view thereof. 16 is a plan view of the substrate, and FIG. 17 is a sectional view taken along line A-1A in FIG.
As can be seen from these drawings, side edge portions 26 and 26 are formed to protrude from both sides of the brush holding frame 22 so that the plane of the substrate 25, that is, the substrate surface and the bottom surface are in contact with each other. This functions as a receiving portion for fixing to the substrate 25 to be described later. However, as shown in the figure, the side edge portion 26 has a width in the protruding direction, and the length of the side surface of the brush holding frame 22. When formed so as to extend moderately in the direction, the contact area in contact with the substrate surface of the brush holding frame 22 is expanded, and the stability of installation is obtained.
[0004]
On the other hand, on the substrate surface of the substrate 25, the width of the bottom surface of the brush holding frame 22 (the side edges 26, 26 of the side edges 26, 26 with respect to the left and right side edges 26, 26 protruding from the lower sides of the brush holding frame 22). The pair of fixing portions 27 and 27 are erected with an interval just corresponding to (including the width). In the lower part where the pair of fixing parts 27 and 27 are in contact with the substrate surface on the opposite side, the side edge part 26 is at least one of the upper edges on the tip side in the width direction, that is, the protruding direction of the side edge part 26. A concave portion 28 is provided so as to receive the portion and be pressed from above. The recess 28 is formed by punching the substrate 25 and bending the plate-like protrusions erected on the substrate surface into a shape in which fingers are bent in directions opposite to each other.
[0005]
As described above, the fixing means is composed of the side edge portions 26, 26 provided on the brush holding frame 22 and the concave portions 28, 28 of the pair of fixing portions 27, 27 provided on the substrate 25. , 27, the brush holding frame 22 is inserted so that the bottom surface of the brush holding frame 22 is slid in accordance with the substrate surface, and the side edge portions 26, 26 on both sides of the brush holding frame 22 are respectively fixed to the fixing portions 27, It is fixed by being fitted into the recesses 28, 28.
In order to fit the side edges 26 and 26 and the recesses 28 and 28 firmly, the recesses 28 and 28 have a shape substantially corresponding to the cross-sectional shape of the side edges 26 and 26. By this fixing means, it is possible to reliably prevent at least the movement of the brush holding frame 22 in the left-right direction, that is, the movement of the circular substrate 25 in the circular direction, the horizontal movement, and the vertical movement in the direction perpendicular to the substrate surface.
[0006]
Next, positioning means for determining the assembly position of the brush holding frame 22 to the substrate 25 will be described with reference to FIGS. This positioning means includes a protrusion 29 provided on the bottom surface side of the brush holding frame 22 and a receiving hole 30 provided in the substrate 25. As shown in FIGS. 13 and 15, the protrusion 29 has a quadrangular shape and protrudes downward from the bottom surface of the brush holding frame 22 by a length corresponding to the plate thickness of the substrate 25. On the other hand, the receiving hole portion 30 of the substrate 25 is a notch hole that is notched into a U-shape that opens toward the outside of the outer edge of the substrate 25 so that the quadrangular protrusion 29 fits exactly.
[0007]
When the brush holding frame 22 is assembled to the substrate 25 in contact with the edge of the protrusion 29 of the brush holding frame 22, the brush holding frame 22 that slides on the substrate surface advances toward the center of the substrate 25. Thus, a guide edge 31 for guiding the traveling direction is formed. That is, when the brush holding frame 22 is inserted between the pair of fixing portions 27, 27 provided on the substrate 25 so that the bottom surface of the holding frame 22 is slid in accordance with the substrate surface, the protrusion 29 is inserted. The edges of the two sides facing the sliding direction are functioned as guides.
[0008]
The depth of the cut from the substrate outer edge toward the substrate center side of the cutout hole as the receiving hole portion is such that the side edge portion 26 of the brush holding frame 22 to be inserted fits into the fixing portion 27 of the substrate 25, and the commutator. It is preferable to set the depth at which the brush tip occupies an appropriate position. Since the predetermined fixing position of the brush holding frame 22 to the substrate 25 is easily determined by this positioning means, the assembling accuracy and work efficiency can be improved. Further, if the positioning means is configured in this way, the protrusion 29 and the receiving hole 30 formed in a quadrilateral shape are fitted to each other so that the movement of the substrate 25 in the circumferential direction and the center direction is shifted or moved. It can be reliably prevented.
[0009]
Even in the brush holding frame 22 that is positioned on the substrate 25 and assembled at the predetermined position as described above, the side edges 26 and 26 of the brush holding frame 22 are estimated as inferred from FIGS. The flexible conductive member 23 from the brush 21 led out from the lead-out hole 24 of the brush holding frame 22 extends just as the fixing portion occupied by the fixing portions 27 of the substrate 25 that covers each part of the substrate 25 is pushed. It hits almost directly under the existing passage, and there is a possibility of causing a short-circuit accident due to contact with the fixing portion 27 planted on the substrate 25 which is a steel plate.
[0010]
For this reason, the covering portion 32 protrudes on the side surface of the brush holding frame 22 below the lead-out hole 24 so as to cover the fixed portion at the lower part on both sides of the brush holding frame 22. The covering portion 32 is formed in a shape in which a rectangular plate is protruded in the shape of a bowl in the horizontal direction, but of course it is not limited to this form. In short, any flexible conductive member 23 called a pigtail may be used as long as contact with the fixing portion 27 and the substrate 25 is cut off.
Since the brush holding frame 22 is generally made of injection-molded synthetic resin having a high insulating property, the cost for forming the covering portion 32 as described above is almost negligible. Therefore, compared with the cost of the insulating tube itself and the work cost covered with this, it is possible to achieve a cost reduction that is not comparable.
[0011]
Next, a movement control part is demonstrated based on FIG.11, FIG.12, FIG.18, FIG.19. The movement restricting portion 33 prevents the movement of the brush holding frame 22, and at least causes the brush holding frame 22 to be brought into contact with a desired engagement portion of the brush holding frame 22 positioned on the substrate 25. It functions to prevent the movement of the substrate 25 in the outer edge direction. The movement restricting portion 33 is a plate-like member formed so that the substrate 25 can be punched out and can be caused from the substrate surface as necessary.
[0012]
The plate-like member as the movement restricting portion 33 uses an end portion 34 (FIG. 14) facing the outer edge of the substrate 25 of the side edge portion 26 formed in the brush holding frame 22 as an engaging portion. The covering portion 32 formed on 22 is extended in the direction facing the outer edge of the substrate 25 in the same manner as the side edge portion 26 shown in the figure, and the end portion 35 may be used as the engagement portion.
Of course, the engaging part is not limited to the part shown here. For example, an engaging part of a concave part or a convex part may be formed in an appropriate part of the side surface of the brush holding frame 22 and used as the engaging part. Since the brush holding frame 22 is a synthetic resin injection-molded product, such an engagement portion can be easily provided without cost.
[0013]
Although there is only one movement restricting portion 33, it is needless to say that a plurality of movement restricting portions 33 can be separately provided at appropriate portions. However, when provided together with the fixing means and positioning means as described above, coupled with these functions and effects, the front and rear, left and right sides of the brush holding frame are in spite of the fact that they are pressed against the brush holding member at only one point. Or the effect which seals the motion to an up-down direction effectively is exhibited.
[0014]
Next, a method for assembling the brush holding frame to the substrate in the motor brush holding device will be described. While the brush holding frame 22 is directed from the outer edge of the substrate 25 toward the center of the substrate 25 and the protrusion 29 on the bottom surface side of the brush holding frame 22 is fitted into the receiving hole 30 of the substrate 25, both fixing portions 27, 27 is inserted so that the bottom surface of the brush holding frame 22 slides on the substrate surface, and the side edge portions 26 and 26 on both sides of the brush holding frame 22 are fitted into the recessed portions 28 and 28 of the fixing portions located on both sides, respectively. Fix it. Thereafter, the brush holding frame 22 is firmly assembled by bringing the tip of the movement restricting portion 33 into contact with the engaging portion on the side surface side of the brush holding frame 22.
As a result, at least the vertical movement and the circumferential movement of the substrate 25 on the surface of the substrate 25 are blocked by the fixing portion 27, and the radial movement of the substrate 25 is blocked by the movement restricting portion. It will be.
[0015]
As described above, conventionally, there are two types of directions in which the flexible conductive member 23 is led out from the brush holding frame 22, and the use of the brush holding frame 22 depending on the direction in which the flexible conductive member 23 is pulled out is a manufacturing cost. Therefore, lead-out holes 24 for drawing out the flexible conductive member 23 are provided on both side surfaces of the brush holding frame 22.
The brush holding frame 22 is fixed to the substrate 25. Since the substrate 25 also serves as a conductive circuit, the brush holding frame 22 is formed of a conductive member.
[0016]
When the brush 21 on the positive electrode side or the flexible conductive member 23 on the positive electrode side comes into contact with the substrate 25, the motor is short-circuited and the motor does not operate normally, so the brush 21 on the positive electrode side and the positive electrode side flexible conductive member 23 are connected to the substrate 25. It is necessary to insulate from. In addition, since the brush temperature during use of the electric motor may reach several hundred degrees Celsius, it is necessary to use a material that does not impair the function due to the heat generated by the brush 21, and it is an insulating member and is relatively deformed by heat. Less thermosetting resin was used.
[0017]
[Problems to be solved by the invention]
The conventional brush holding device for an electric motor is configured as described above, and since the lead-out holes through which the flexible conductive member is led are provided on both side surfaces of the brush holding frame, the strength near the lead-out hole is weak. During normal use, no force is applied to this part. However, if the force is applied in the direction of arrow B in FIG. If the force is concentrated and exceeds the allowable stress, it may break.
[0018]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a brush holding device that is not easily damaged by applying an excessive force by improving the strength of the brush holding frame. And
[0019]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a brush holding frame for an electric motor having a lead-out hole on both sides for leading a flexible conductive member for guiding a current from or to the brush, and having a brush for urging the brush toward the commutator. be one in which the bottom portion for receiving the brush biasing reaction force energizing member is formed integrally with both side surfaces, the bottom of the inner and Rutotomoni provided with projections integrally, the height direction of the height-direction center and derived hole projections The center is the same.
[0020]
According to a second aspect of the present invention, there is provided a brush holding frame for an electric motor in which the center of the brush urging member holding portion for holding the outer periphery of the brush urging member is the same as the center of the protrusion.
[0021]
According to a third aspect of the present invention, there is provided the brush holding frame for an electric motor in which the protrusions and the center of the brush holding portion in the height direction are made to coincide.
[0022]
According to a fourth aspect of the present invention, the brush holding frame for an electric motor is configured such that the protrusion is hollow.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 is a front view showing a brush holding frame in a brush holding device for an electric motor according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view taken along the line DD in FIG. In the figure, 1 is a brush holding frame molded from a highly insulating synthetic resin, 2 is a lead-out hole for leading out a flexible conductive member provided on both side surfaces of the brush holding frame 1, and 3 is a substrate surface and brush. Side edges 4 are formed so as to protrude from the bottom surface of the holding frame 2, 4 is a covering portion protruding from the side surface of the brush holding frame 1, and 5 is a positioning means for determining the assembly position of the brush holding frame 2 on the substrate. A projecting portion, 6 is a bottom portion of the brush holding frame 2, 7 is a protrusion provided on the inner surface of the bottom portion 6, 8 is a brush urging member holding portion for holding the outer periphery of the brush urging member, and 9 is a brush holding portion.
[0024]
3 is a front view showing a state in which the brush 10 and the brush urging member 11 are assembled to the brush holding frame 1 , and FIG. 4 is a cross-sectional view taken along line EE of FIG. Is provided with the protrusions 7 on the bottom 6 the inner surface as described above, even if derived holes 2 on both sides of the brush holding frame 1, the strength of the brush holding frame 1 is increased, even if excessive force corruption It is possible to obtain a brush holding frame 1 that is difficult to perform.
Further, the height direction center of the projection 7 and the lead-out hole 2 can be made to coincide with each other, and by configuring in this way, the projection 7 can be arranged at a portion where the stress is most concentrated, so that the strength is more effectively increased. Can be improved.
[0025]
Furthermore, the center of the protrusion 7 and the brush urging member holding portion 8 that holds the brush urging member 11 can be matched. With this configuration, the protrusion 7 can be disposed in the central empty space of the brush urging member 11, so that a larger protrusion 7 can be disposed on the brush holding frame bottom 6.
Further, the center of the projection 7 and the brush holding portion 9 in the height direction are matched, and the projection 7 of the brush holding frame 1 is provided at the center of the brush holding portion 9, whereby the brush urging force by the brush urging member 11 is applied to the brush 10. Therefore, uneven wear of the brush 10 due to eccentricity of the brush biasing force can be prevented.
Furthermore, by making the center of the protrusion 7 hollow, the mass of the brush holding frame 2 can be reduced without significantly reducing the strength.
[0026]
Embodiment 2. FIG.
Regarding the form of the protrusion 7, as shown in FIGS. 5 and 6, the bottom 6 side may be an open end. Moreover, as shown in FIG. 7, FIG. 8, you may comprise so that the bottom part 6 side may be closed and an anti-bottom part side may become an opening end. Furthermore, as shown in FIGS. 9 and 10, the brush holding portion 9 side of the protrusion 7 can be configured as an open end.
[0027]
【The invention's effect】
According to the brush holding frame for an electric motor according to the first aspect of the present invention, the both sides have the lead-out holes for leading the flexible conductive member for guiding the current from or to the brush, and the brush is biased to the commutator. The bottom part of the brush urging member that receives the brush urging reaction force is formed integrally with both side surfaces, and the protrusions are provided integrally with the inner surface of the bottom part, so there are lead-out holes on both side surfaces of the brush holding frame. However, the strength of the brush holding frame is improved, and even if an excessive force is applied, it is difficult to break.
[0028]
Furthermore, since the center in the height direction of the protrusion and the center in the height direction of the lead-out hole are made coincident, the protrusion can be arranged in the portion where the stress is most concentrated, and the strength can be improved.
[0029]
According to the brush holding frame for an electric motor according to the second aspect of the present invention, since the center of the protrusion and the center of the brush urging member holding part for holding the outer periphery of the brush urging member is the same, the large protrusion is arranged in the brush holding frame. Can be placed at the bottom.
[0030]
According to the brush holding frame for an electric motor according to the third aspect of the present invention, since the protrusions and the center of the brush holding portion in the height direction are made to coincide, it is possible to prevent uneven wear of the brush due to the eccentricity of the brush urging force.
[0031]
According to the brush holding frame for an electric motor according to claim 4 of the present invention, since the protrusion is configured to be hollow, the mass of the brush holding frame can be reduced without greatly reducing the strength.
[Brief description of the drawings]
FIG. 1 is a front view showing a brush holding frame according to Embodiment 1 of the present invention.
FIG. 2 is a cross-sectional view taken along the line DD in FIG.
FIG. 3 is a front view showing a state in which a brush and a brush urging member are assembled to the brush holding frame according to the first embodiment of the present invention.
4 is a cross-sectional view taken along line EE in FIG. 3;
FIG. 5 is a front view showing a brush holding frame according to a second embodiment of the present invention.
6 is a cross-sectional view taken along line FF in FIG.
FIG. 7 is a front view showing a brush holding frame according to a second embodiment of the present invention.
8 is a cross-sectional view taken along line GG in FIG.
FIG. 9 is a front view showing a brush holding frame according to a second embodiment of the present invention.
10 is a cross-sectional view taken along line HH in FIG.
FIG. 11 is a plan view showing a conventional brush holding device.
FIG. 12 is a front view showing a state in which a brush and a brush urging member are assembled to a conventional brush holding frame.
FIG. 13 is a front view showing a conventional brush holding frame.
FIG. 14 is a plan view showing a conventional brush holding frame.
FIG. 15 is a side view showing a conventional brush holding frame.
FIG. 16 is a plan view of a conventional substrate.
17 is a cross-sectional view taken along line AA in FIG.
FIG. 18 is a front view showing a state in which a brush and a brush urging member are assembled to a conventional brush holding frame.
FIG. 19 is a front view showing a state in which a brush and a brush urging member are assembled to a conventional brush holding frame.
[Explanation of symbols]
1 brush holding frame, 2 lead-out hole, 6 bottom, 7 projection, 8 brush urging member holding part,
9 Brush holding part, 10 brush, 11 brush urging member.

Claims (4)

Both sides have lead-out holes that lead out flexible conductive members that conduct current from or to the brush, and the bottoms that receive the brush bias reaction force of the brush biasing member that biases the brush toward the commutator characterized in that the motor brush holding frame which is integrally formed, were matched Rutotomoni provided with projections on the inner surface integral with the bottom, and a height direction center of a height direction center and the derivation hole of the protrusion and A brush holding frame for an electric motor. The brush holding frame for an electric motor according to claim 1, wherein the center of the brush urging member holding portion for holding the outer periphery of the brush urging member and the center of the protrusion are the same. The brush holding frame for an electric motor according to claim 1 or 2, wherein the protrusion and the center of the brush holding portion in the height direction are made to coincide. The brush holding frame for an electric motor according to any one of claims 1 to 3, wherein the protrusion is configured to be hollow.

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