JP4360035B2 - Motor brush holding structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motor brush holding structure in which a carbon brush is attached and held on an insulating substrate by a brush holder.
[0002]
[Prior art]
Conventionally, as shown in FIG. 8, claw-like pieces 3 that are paired on both sides are integrally extended from a metal brush holder 2 that surrounds and holds the carbon brush 1, and each claw-like piece 3 is made to be an insulating substrate. There is known a motor brush holding structure in which the carbon brush 1 is attached and held on the front side of the insulating substrate 4 by being inserted into 4 and bent on the back side of the insulating substrate 4. The motor brush holding structure is employed in a vibration tool such as an electric impact driver.
[0003]
In this case, a terminal 8 made of a metal material is interposed between the carbon brush 1 and the insulating substrate 4 to dissipate heat from the carbon brush 1, and penetrates the terminal 8 and the insulating substrate 4. A slit 6 is formed. In addition, the brush holder 2 has a substantially U-shaped cross section, and claw-like pieces 3 are integrally projected and extended from both side base ends of the brush holder 2. And the nail | claw-shaped piece 3 of both sides is penetrated by each slit 6, and it opposes on the back side of the insulating board | substrate 4, and each is bent inside and crimped. Thereby, the brush holder 2 is attached and fixed to the front side of the insulating substrate 4, and the carbon brush 1 is held inside the brush holder 2.
[0004]
[Problems to be solved by the invention]
However, in the above conventional technique, since it is used for a vibration tool, impact and vibration are applied to the motor brush holding structure. Therefore, as shown in FIG. 9, the friction between the claw-like piece 3 of the brush holder 2 and the insulating substrate 4 due to impact or vibration causes wear on the back surface of the insulating substrate 4 made of synthetic resin. As a result, the brush holder 2 moves rattling with the incompletely fixed state of the claw piece 3 and the function of the brush holder 2 for holding the carbon brush 1 is impaired. It was. Further, if the carbon brush 1 is not securely held by the brush holder 2, the contact state between the carbon brush 1 and the commutator becomes unstable, and there is a problem that a predetermined motor characteristic cannot be obtained.
[0005]
The present invention has been invented in order to solve the above-mentioned problems in the prior art, and the problem is that the carbon brush is securely attached and held by the brush holder so that it does not rattle the insulating substrate. By providing a motor brush holding structure that does not impair the holding function and motor characteristics of the brush holder due to impact and vibration, does not cause trouble over time, and has a long life by improving heat dissipation. is there.
[0006]
[Means for Solving the Problems]
In the motor brush holding structure according to the first aspect of the present invention, the claw-like pieces that are paired on both sides are integrally extended from a metal brush holder that surrounds and holds the carbon brush, and each claw-like piece is insulated. A motor brush holding structure in which the carbon brush is attached and held on the front side of the insulating substrate by being inserted into the substrate and bent at the back side of the insulating substrate. A metal terminal is interposed between the substrate and a metal bottom plate on the back side of the insulating substrate. The claw-like piece is inserted into the terminal and the bottom plate, and the claw-like piece is placed on the back side of the bottom plate. the Ri Do caulking by bending to form an outer shape substantially the recess of matching shape of the bottom plate on the back surface of the insulating substrate, it is housed engaged engaged with the bottom plate to the recess.
[0007]
Therefore, in this case, the claw-like piece extending from the brush holder is inserted into the insulating substrate and the metal bottom plate from the terminal, and is bent and caulked on the back side of the bottom plate. The part abuts against the back surface of the bottom plate, but the corresponding contact part is strong, hardly deformed, and hardly wears. Therefore, the brush holder is firmly fixed to the insulating substrate so as not to wobble, and the carbon brush surrounded and held by the brush holder is securely attached and held so as not to rattle the insulating substrate. .
[0008]
As described above, when the holding function of the brush holder is ensured, the carbon brush can be held in a stable state to obtain a predetermined motor characteristic, and these functions and characteristics are not impaired by impact and vibration, and are not deteriorated over time. It will not cause any trouble. In addition, the heat dissipation action is improved by the heat conduction from the metal brush holder to the metal bottom plate, and the service life is extended. Furthermore, since the metal terminal is disposed between the carbon brush and the insulating substrate, further heat dissipation of the carbon brush can be achieved. In addition, the bottom plate is housed compactly in the thickness direction in the recess on the back surface of the insulating substrate, and the bottom plate is engaged with the recess so that the outer shape substantially matches, so the rotation of the bottom plate is restricted. As a result, the brush holder is attached and fixed in a more stable state.
[0009]
The motor brush holding structure according to claim 2 of the present invention is the motor brush holding structure according to claim 1, wherein the bottom plate is formed with slits that are paired on both sides, and the nail-like pieces on both sides that are inserted through the slits are formed. It is characterized by facing and bending inward.
[0010]
Therefore, especially in this case, the claw-like pieces on both sides inserted into each slit are opposed and bent inward, so that the insulating substrate and the bottom plate are wrapped with the same claw-like pieces between the slits on both sides. The brush holder is attached and fixed more firmly.
[0011]
The motor brush holding structure according to claim 3 of the present invention is the motor brush holding structure according to claim 2, wherein a plurality of pairs of claw-like pieces and slits are arranged in the longitudinal direction of the slits. .
[0012]
Therefore, especially in this case, since a plurality of pairs of claw-like pieces and slits are arranged side by side in the longitudinal direction, the brush holder attached and fixed in the longitudinal direction moves so as to change its orientation. It is difficult and is more securely attached and fixed at a predetermined position.
[0015]
A motor brush holding structure according to a fourth aspect of the present invention is the motor brush holding structure according to any one of the first to third aspects, wherein the motor brush holding structure is bonded to a caulked portion of a claw-like piece bent at the back side of the bottom plate. It is characterized in that an agent is applied and fixed.
[0016]
Therefore, in this case, in particular, since the adhesive is applied and fixed to the caulking portion of the claw-like piece bent on the back side of the bottom plate, the caulking portion is reinforced so as not to move or deform, and the brush holder Is more firmly attached and fixed.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 to 5 show an embodiment corresponding to all of claims 1 to 5 of the present invention. The motor brush holding structure of the embodiment includes a metal brush holder 2 that surrounds and holds the carbon brush 1. The insulative substrate is formed by projecting and extending the claw-like pieces 3 that are paired on both sides, inserting each claw-like piece 3 into the insulating substrate 4 and bending the claw-like pieces 3 on the back side of the insulating substrate 4. The carbon brush 1 is attached and held on the front side of 4. In this case, a metal bottom plate 5 is disposed on the back side of the insulating substrate 4, the claw-like piece 3 is inserted into the bottom plate 5, and the claw-like piece 3 is bent on the back side of the bottom plate 5. I'm cautious. As shown in FIG. 5, the bottom plate 5 is formed in a substantially rectangular shape and is made of a copper plate material having high conductivity.
[0018]
In the motor brush holding structure of the embodiment, the bottom plate 5 is formed with slits 6 that are paired on both sides, and the claw-like pieces 3 that are inserted into the slits 6 are opposed to each other and bent inward. It is tightening. In this case, as shown in FIGS. 2, 4, and 5, a plurality of pairs of claw-like pieces 3 and slits 6 are arranged in the longitudinal direction of the slits 6, and the bottom plate 5 is disposed on the back surface of the insulating substrate 4. A recess 7 having a shape substantially matching the outer shape is formed, and the bottom plate 5 is accommodated and engaged with the recess 7. Further, in the motor brush holding structure of the embodiment, an adhesive is applied to the caulked portion of the claw-like piece 3 bent on the back side of the bottom plate 5 and fixed.
[0019]
The motor brush holding structure of this embodiment is employed for a vibration tool such as an electric impact driver. In this case, as shown in FIGS. 1 to 4, for further heat dissipation of the carbon brush 1, a terminal 8 made of a copper plate material is interposed between the carbon brush 1 and the insulating substrate 4. 5 is formed so as to communicate with the insulating substrate 4 and the terminal 8. The brush holder 2 has a substantially U-shaped cross section, and claw-like pieces 3 are integrally projected and extended from both side base ends of the brush holder 2. Then, the claw-like pieces 3 on both sides are inserted into the respective slits 6 from the front side of the insulating substrate 4, faced on the back side of the bottom plate 5, and bent to the inside. Thereby, the brush holder 2 is attached and fixed to the front side of the insulating substrate 4, and the carbon brush 1 is held in the space surrounded by the brush holder 2.
[0020]
As shown in FIG. 2, the brush holder 2 protrudes from the surface of the insulating substrate 4 in a gate shape, and the carbon brush 1 slides in the cylinder direction in a substantially cylindrical space surrounded by the brush holder 2. It is accommodated and held freely. The tip 1 a of the carbon brush 1 on the side in contact with the commutator (not shown) protrudes slightly from one open end of the brush holder 2. Also, the side wall 2a on one side of the brush holder 2 is formed with a first groove 10 that is long in the cylinder direction in which the pigtail 9 led out from the carbon brush 1 is inserted and can be moved in the cylinder direction. One end of the groove 10 reaches the vicinity of the one opening end, and the other end is opened at the other opening end.
[0021]
As shown in FIGS. 3 to 5, the insulating substrate 4 is a substantially disc-shaped synthetic resin molded product, and a pair of carbon brushes 1 held by the brush holder 2 are opposed to each other on the front side. In addition, spring materials 11 are disposed on the opposite sides of the pigtails 9 of both brush holders 2, and the spring materials 11 elastically bias the carbon brush 1 forward. A rotor (not shown) is rotatably held in a circular opening 12 formed in the center of the insulating substrate 4, and the tip 1a of the carbon brush 1 is slid on the commutator provided on the rotor. Touched.
[0022]
As shown in FIG. 6, the entire brush holder 2 is formed by bending a copper plate material and pressing it integrally, and is opposed to the side wall 2a in which the first groove 10 of the brush holder 2 is formed. On the opposite side wall portion 2b, a second kerf 13 is formed which is long in the cylinder direction in which the working side end portion of the spring material 11 is inserted and is movably accommodated in the cylinder direction. Moreover, the side wall 2a in which the first groove 10 is formed is one opening end on the side from which the tip 1a of the carbon brush 1 is slightly protruded and extends outward to bend the reinforcing piece. Therefore, the side wall 2a is hardly deformed and damaged.
[0023]
Therefore, in the motor brush holding structure of the embodiment, the claw-like piece 3 extending integrally from the brush holder 2 is inserted from the synthetic resin insulating substrate 4 to the metal bottom plate 5, Since it is bent and caulked on the back side of the bottom plate 5, the caulked portion of the claw-like piece 3 comes into contact with the back surface of the same base plate 5, but the corresponding contact portion is the same base metal plate 5 and is hard and hard to deform. Is also difficult to occur. Therefore, the brush holder 2 is firmly fixed to the insulating substrate 4 so as not to wobble, and the carbon brush 1 surrounded and held by the brush holder 2 is surely prevented from rattling against the insulating substrate 4. Is attached and held.
[0024]
As described above, when the holding function of the brush holder 2 is ensured, the carbon brush 1 can be held in a stable state with high accuracy to obtain a predetermined motor characteristic. It will not be damaged and will not cause any trouble over time. In addition, since the heat generated by the carbon brush 1 is thermally conducted from the metal brush holder 2 to the metal bottom plate 5, the heat dissipation action is improved and the life of the carbon brush 1 is extended.
[0025]
Moreover, in the motor brush holding structure of this embodiment, the claw-like pieces 3 on both sides inserted through the slits 6 are opposed and bent inward, so that the insulating substrate 4 and the bottom plate 5 are on both sides. The brush holder 2 is more firmly attached and fixed by being sandwiched between the slits 6 so as to be wrapped with the same claw-like pieces 3. In addition, in this case, a plurality of pairs of claw-like pieces 3 and slits 6 are arranged side by side in the longitudinal direction of the slits 6, so that the orientation of the brush holder 2 attached and fixed in the longitudinal direction changes. It is difficult to move around, and it is more securely attached and fixed at a predetermined position.
[0026]
Furthermore, in the motor brush holding structure of this embodiment, the bottom plate 5 is accommodated compactly in the thickness direction in the recess 7 on the back surface of the insulating substrate 4, and the bottom plate 5 and the outer shape of the recess 7 are substantially the same. Since they are mated and engaged, the rotational displacement of the bottom plate 5 is restricted, and the brush holder 2 is attached and fixed in a more stable state. And since an adhesive agent is apply | coated and fixed to the caulking part of the both nail | claw-shaped pieces 3 bent by the back side of the baseplate 5, this caulking part is reinforced so that it may not move or deform | transform, and the brush holder 2 Is more firmly attached and fixed.
[0027]
【The invention's effect】
As described above, in the motor brush holding structure according to the first aspect of the present invention, the caulking portion is reinforced by the bottom plate so that it is difficult to deform and wear, and the brush holder is firmly fixed to the insulating substrate. The carbon brush is securely attached to and held on the insulating substrate by the brush holder, and the holding function of the brush holder is ensured. Further, the carbon brush is held in a stable state, and predetermined motor characteristics can be obtained. These functions and characteristics are not impaired by impact and vibration, and do not cause trouble over time. Furthermore, since the heat radiation effect is improved by the bottom plate, the life can be extended. Furthermore, since the metal terminal is disposed between the carbon brush and the insulating substrate, further heat dissipation of the carbon brush can be achieved. Further, the bottom plate is accommodated in a recess in the back surface of the insulating substrate, and the rotation of the bottom plate is restricted, so that the brush holder is fixed and fixed in a more stable state.
[0028]
In the motor brush holding structure according to claim 2 of the present invention, in particular, since the insulating substrate and the bottom plate are sandwiched between the slits on both sides so as to be wrapped by the two claw-like pieces, the brush holder is made stronger. It is fixed.
[0029]
Further, in the motor brush holding structure according to claim 3 of the present invention, the brush holder is particularly attached and fixed so as to face the longitudinal direction in which a plurality of pairs of claw-like pieces and slits are arranged. It is more securely attached and fixed at the position.
[0031]
In the motor brush structure according to claim 4 of the present invention, the brush holder is particularly firmly attached and fixed because the caulking portion is reinforced with an adhesive that is applied and fixed.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a main part of a motor brush holding structure according to an embodiment of the present invention.
FIG. 2 is a perspective view showing a main part of the motor brush holding structure.
FIGS. 3A and 3B show an entire holding state of an insulating substrate in the motor brush holding structure, wherein FIG. 3A is a plan view and FIG. 3B is a side view thereof.
4 is a cross-sectional view taken along line XX in FIG.
FIG. 5 is a bottom view showing the entire holding state of the insulating substrate in the motor brush holding structure.
FIGS. 6A and 6B show a brush holder before mounting and fixing in the motor brush holding structure, wherein FIG. 6A is a plan view thereof, FIG. 6B is a left side view thereof, FIG. 6C is a right side view thereof, and FIG. The rear view.
FIG. 7 is an enlarged plan view of a main part in FIG.
FIG. 8 is a cross-sectional view of an essential part showing a conventional motor brush holding structure.
FIG. 9 is a cross-sectional view of a main part showing a worn deformation state of the motor brush holding structure.
[Explanation of symbols]
1 Carbon brush 2 Brush holder 3 Claw-shaped piece 4 Insulating substrate 5 Bottom plate 6 Slit 7 Recess

Claims (4)

From the metal brush holder that surrounds and holds the carbon brush, claw-like pieces that are paired on both sides are extended and integrated, and each claw-like piece is inserted into the insulating substrate and bent on the back side of the insulating substrate. A motor brush holding structure in which the carbon brush is attached and held on the front side of the insulating substrate by caulking, and a metal terminal is interposed between the carbon brush and the insulating substrate, disposing a metallic base plate on the back side of the insulating substrate, Ri Do caulking by bending the pawl-shaped piece at the back of the also inserted through the claw-shaped piece to the terminal and the bottom plate the bottom plate, the insulating substrate motor brush holding structure to form an outer shape substantially the recess of matching shape, you characterized in that engaged accommodating engagement of the bottom plate in the recess of the bottom plate on the back.  2. The motor brush holding structure according to claim 1, wherein slits that are paired on both sides are formed in the bottom plate, and the claw-like pieces on both sides that are inserted through the slits are opposed and bent inward.  The motor brush holding structure according to claim 2, wherein a plurality of pairs of claw-like pieces and slits are arranged side by side in the longitudinal direction of the slits. The motor brush holding structure according to any one of claims 1 to 3 , wherein an adhesive is applied and fixed to a caulked portion of a claw-like piece bent on the back side of the bottom plate.

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