JP3661832B2 - Commutator manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the production how commutator provided with slits over the resin portion inner periphery of the outer peripheral surface of the substantially cylindrical conductor portion.
[0002]
[Prior art]
Conventionally, in an electric motor constituting an electric blower of a vacuum cleaner, the rotor has a commutator in which a plurality of commutator pieces in contact with a carbon brush are integrally provided on a rotating shaft. As shown in FIG. 5, this commutator has a substantially cylindrical shape on the inner peripheral side of a substantially cylindrical resin portion 52 provided with a plurality of conductive commutator pieces 51 located on the outer peripheral surface in a substantially cylindrical shape. The rotation shaft 54 is integrally inserted and held via a sleeve 53. In addition, the outer peripheral surface of the resin part 52 is formed in a concavo-convex shape at equal intervals in the circumferential direction so that the conductive bulge part 51a provided on the inner peripheral side of the commutator piece 51 is engaged. . The commutator 55 is cut along the axial direction from the outer peripheral surface of the substantially cylindrical conductive member 56 provided in a substantially cylindrical shape on the outer peripheral surface of the resin portion 52 to the resin bulging portion 52a of the resin portion 52. A plurality of commutator pieces 51 and 51 are formed by cutting the slit 58 with the blade 57 to cut the conductive member 56 in the circumferential direction.
[0003]
[Problems to be solved by the invention]
However, in the conventional commutator 55 shown in FIG. 5, the edge of the slit 58 located at the resin portion 52 has a square shape. When the driving of the electric blower is stopped, no heat is generated, moisture in the atmosphere is absorbed by the resin part 52, and when the electric blower is driven, heat is generated to evaporate the moisture in the resin part 52. As a result, the resin part 52 is in a state of repeatedly expanding and contracting. For this reason, there is a problem that the stress of expansion / contraction concentrates on the corner portion of the slit 58 and the crack 59 may be generated as shown in FIG.
[0004]
The present invention has been made in view of the above problems, and an object thereof is to provide dispersion prepared how suppress commutator generation of crack stress.
[0005]
[Means for Solving the Problems]
Method of manufacturing a commutator 請 Motomeko 1 wherein the substantially cylindrical resin portion a plurality of substantially cylindrical between the resin swollen portion of the conductive member projecting from the outer peripheral surface of the inner circumferential side a plurality of provided After forming the resin part integrally with the conductive member so as to locate the conductive bulge part, a slit is formed along the axial direction from the outer peripheral surface of the conductive member formed on the resin part to the resin part. the method of manufacturing a commutator forming a plurality of commutator bars to the conductive member, through said resin bulging portion extending axially therethrough edge located on at least the inner diameter side of the arc shape when forming the resin portion The slit is formed by forming a hole and cutting from the outer peripheral surface of the conductive member to the through hole .
[0006]
When the resin portion is formed, the edge that penetrates the resin bulge portion in the axial direction and is located at least on the inner diameter side forms an arc-shaped through hole, and is protruded from the outer peripheral surface of the substantially cylindrical resin portion. From the outer peripheral surface of the substantially cylindrical conductive member formed integrally with the resin portion so as to position the plurality of conductive bulge portions provided on the inner peripheral side of the substantially cylindrical conductive member between the plurality of resin bulge portions. Since a plurality of commutator pieces are formed by cutting across the hole , the edges located in the resin part of the slit are arcuate, preventing stress concentration and preventing damage such as cracks in the resin part. It becomes easy to form slits.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the configuration of an embodiment of an electric blower of the present invention will be described with reference to the drawings.
[0008]
In FIG. 2, reference numeral 1 denotes an electric blower for a vacuum cleaner, for example, and this electric blower 1 has an electric motor 2. The electric motor 2 has a substantially cylindrical body case 3, and a motor body 4 is housed inside the body case 3.
[0009]
The body case 3 is formed with an opening 5 on the front end surface, which is one end in the axial direction, and a flange portion 6 having a substantially L-shaped cross section that protrudes around the opening 5 in the outer peripheral direction. Is bent. The rear end surface which is the other end in the axial direction of the body case 3 is closed by the rear plate portion 7, and the central portion of the rear plate portion 7 projects rearward in a substantially cylindrical shape toward the inner peripheral surface side. A motor head portion 9 for receiving the bearing 8 is provided.
[0010]
Further, a pair of air outlets (not shown) are formed in the peripheral surface in the vicinity of the rear part of the body case 3 so as to be located substantially in the radial direction.
[0011]
Further, a longitudinal plate-like bridge portion 12 is attached to the front end portion of the trunk case 3 with screws 13 so as to bridge the radial direction of the trunk case 3 and cover a part of the opening 5. A bearing portion 15 that protrudes in a substantially cylindrical shape toward the front, accommodates the bearing 8 on the inner peripheral side, and opens the through hole 14 at the substantially center is provided at a substantially central portion of the bridge portion 12. Note that the opening 5 of the body case 3 that is not covered by the bridge portion 12 serves as a ventilation hole (not shown).
[0012]
On the other hand, the motor body 4 includes a field 18 that is a substantially cylindrical stator fixed to the body case 3, and an armature 19 that is an electric element disposed inside the field 18. The armature 19 is disposed substantially coaxially in the body case 3 with both ends of a rotor shaft 20 serving as a rotation shaft provided at the shaft center being rotatably supported by bearings 8 and 8.
[0013]
Further, a pair of brush mechanisms 22 are positioned substantially in the radial direction in the body case 3 and are partially protruded from the peripheral surface and fixed by screws 13. The brush mechanism 22 includes a carbon brush 24 as a slider that is in sliding contact with the outer peripheral surface of the commutator 23 provided in the armature 19, and a brush holder 25 that holds the carbon brush 24. .
[0014]
Further, as shown in FIGS. 1 and 2, the commutator 23 is provided integrally with a substantially cylindrical sleeve 26 that fits the rotor shaft 20 on the inner periphery thereof, and is provided on the outer periphery side of the sleeve 26, for example, a hard synthetic resin. And a resin portion 27 formed in a substantially cylindrical shape, and a conductive material in which a plurality of substantially equal intervals are provided on the outer peripheral side of the resin portion 27 and the carbon brush 24 is in sliding contact with the outer peripheral surface. Commutator pieces 28, 28. The outer peripheral surface of the resin portion 27 has a wall shape along the axial direction and a tip portion that protrudes wide in the circumferential direction, and a plurality of resin bulge portions 27a are provided in an uneven shape at equal intervals in the circumferential direction. It has been. Further, the commutator piece 28 is provided with a conductive bulging portion 28a that is wall-shaped along the axial direction and has a tip that protrudes wide in the circumferential direction and engageable between the resin bulging portions 27a and 27a. Yes.
[0015]
Further, the commutator 23 is provided with a plurality of slits 29 and 29 radially extending in the axial direction from the outer peripheral surface toward the center. The slits 29, 29 are provided with a plurality of conductive bulging portions 28a, 28a on the inner peripheral side so as to engage the resin bulging portions 27a, 27a of the resin portion 27 on the outer peripheral surface of the resin portion 27. The conductive portion 28b as a conductive member is integrally formed in a substantially cylindrical shape, and the resin bulge portion of the resin portion 27 is formed from the outer peripheral surface of the conductive portion 28b corresponding to the resin bulge portions 27a and 27a of the resin portion 27. It is formed by cutting with the cutting blade 30 continuously over 27a. By cutting the slits 29 and 29, the conductive portions 28b are cut at substantially equal intervals in the circumferential direction to form a plurality of commutator pieces 28 and 28. Since the slits 29 and 29 are provided corresponding to the resin bulges 27a, the commutator piece 28 is provided with conductive bulges 28a that engage between the resin bulges 27a and 27a, respectively. Therefore, the commutator piece 28 does not fall off.
[0016]
Further, the brush holder 25 is supported in a state in which the longitudinal direction is substantially orthogonal to the axial direction of the rotor shaft 20, and is supported in a state in which a part projects to the outside of the body case 3. The carbon brush 24 is pressed by the brush holder 25 and is brought into sliding contact with the commutator 23 so that the carbon brush 24 and the commutator 23 are electrically connected to each other.
[0017]
On the other hand, a diffuser 31 is fixed to the front side of the bridge portion 12 with screws 13. Further, a fan 32 is disposed in front of the diffuser 31. One end of the rotor shaft 20 from which the electric motor 2 protrudes is fitted into the center of the fan 32, and a sleeve ring 33 that fits into the rotor shaft 20 and one end portion that is the front side of the rotor shaft 20 are formed. It is clamped via washers 36 and 36 by a hexagonal nut 35 that is screwed to the screw portion 34 and fixed to the front end portion of the armature 19 of the motor main body portion 4.
[0018]
Further, a substantially cylindrical fan cover 40 is fitted to the outer peripheral portion of the flange portion 6 of the body case 3, and the fan 32 is covered by the fan cover 40. The fan cover 40 is formed with an air inlet 42 at the center of the front surface that opens to the approximate center of the fan 32 and faces the air vent 41 that communicates from the inside of the fan 32 to the outer periphery, and a rear opening on the entire rear surface. 43 is formed in an opening to form a substantially cylindrical shape.
[0019]
Next, the manufacturing process of the commutator 23 will be described.
[0020]
First, the sleeve 26, the resin portion 27, and the conductive portion 28b are laminated in advance to form a commutator element body 23a as shown in FIG. When forming the commutator element body 23a, when forming the resin part 27, the resin part 27 is formed by positioning an elongated cylindrical pin (not shown) at a position corresponding to the resin bulge part 27a, A pin 45 is removed to form an elongated circular hole 45 that penetrates in the axial direction.
[0021]
Then, the slits 29 and 29 are formed by cutting with the cutting blade 30 continuously from the outer peripheral surface of the conductive portion 28b to the through hole 45 formed in the resin bulging portion 27a of the resin portion 27. By continuously cutting and forming over the through hole 45, the edge located at the resin bulging portion 27a of the resin portion 27 of the slits 29, 29 is formed in an arc shape. Then, the commutator 23 is attached to the rotor shaft 20 to constitute the motor main body 4 and assembled in the body case 3 to assemble and form the electric motor 2 of the electric blower 1.
[0022]
As described above, in the above embodiment, the commutator 23 of the motor main body 4 of the electric motor 2 is continuously extended from the outer peripheral surface of the conductive portion 28b to the resin bulging portion 27a of the resin portion 27 provided on the inner peripheral side. Then, the slits 29 and 29 are cut and formed, and the edges of the slits 29 and 29 located at the resin bulging portion 27a are formed in an arc shape, so that the edges shown in FIG. Stress concentration can be prevented. For this reason, for example, the driving of the electric blower 1 is stopped, the resin part 27 absorbs moisture in the atmosphere, and the moisture of the resin part 27 absorbed by the heat generated by the driving of the electric blower 1 evaporates. Even if the resin portion 27 repeatedly expands and contracts, stress due to expansion and contraction is dispersed at the arc-shaped portion of the slit 29 to prevent stress concentration, and a crack 59 is generated from the corner portion of the slit 58 shown in FIG. The crack 59 spreads and the resin bulging portion 27a falls off, so that the commutator piece 28 can be prevented from being damaged.
[0023]
In addition, an elongated circular hole 45 is formed in the bulging portion 27a of the resin portion 27, and the slit 29 is continuously formed over the through hole 45, so that the edge located in the resin portion 27 is easily rounded. An arcuate slit 29 can be formed.
[0024]
In addition, in each said embodiment, although the electric blower 1 for vacuum cleaners was demonstrated, any other electric motor is applicable.
[0025]
Also, the resin portion 27 is provided with an elongated circular hole 45 and a slit 29 is provided over the hole 45. For example, as shown in FIG. 3 and FIG. That is, a through hole 48 having a substantially semi-cylindrical shape with an arcuate edge on the direction side from the outer peripheral surface, which is the direction in which the slit 29 is cut and formed, is formed over the through hole 48. 45 is sufficient if at least the edge on the inner diameter side is arcuate.
[0026]
Further, for example, a concave groove is formed in advance along the axial direction at the substantially center of the outer peripheral surface of the resin bulging portion 27a of the resin portion 27, and a concave groove having an arcuate edge located on the inner diameter side is provided in advance. The conductive portion 28b may be provided so as not to be closed, and the conductive portion 28b may be continuously cut across the groove and cut from the outer peripheral surface to be cut to provide the slit 29.
[0027]
Furthermore, although the description has been made by providing the through holes 45 and 48 at the same time when the resin portion 27 is formed, the holes may be formed after the resin portion 27 is formed in advance. In addition, according to the structure which forms the through-holes 45 and 48 simultaneously, manufacturability can be improved.
[0028]
【The invention's effect】
According to the manufacturing method of the commutator 請 Motomeko 1 wherein the edge is located at least the inner diameter side through the resin swollen portion in the axial direction during the formation of the tree fat portion forms an arcuate through hole, Since a plurality of commutator pieces are formed by cutting from the outer peripheral surface of the conductive member to the through-hole , the edges located at the resin part of the slit are arcuate, preventing stress concentration and cracking in the resin part. It is possible to easily form a slit that can prevent damage such as the occurrence of a crack.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view in which a portion of a commutator showing an embodiment of the present invention is cut away.
FIG. 2 is a side cross-sectional view of the electric blower shown in FIG.
FIG. 3 is a cross-sectional view in which a portion of a commutator showing another embodiment of the present invention is cut away.
FIG. 4 is a sectional view showing the vicinity of the slit.
FIG. 5 is a cross-sectional view with a part cut away showing a commutator of a conventional example.
FIG. 6 is a sectional view showing the vicinity of the slit.
[Explanation of symbols]
2 Electric motor
23 Commutator
24 Carbon brush as a slider
27 Resin section
28 Commutator piece
28b Conductive part as conductive member
29 Slit
45, 48 through holes

Claims (1)

The resin portion is disposed so that a plurality of conductive bulge portions provided on the inner peripheral side of the substantially cylindrical conductive member are positioned between the plurality of resin bulge portions protruding from the outer peripheral surface of the substantially cylindrical resin portion. after integrally formed with the conductive member, the rectifier that forms a plurality of commutator bars to the conductive member to form a slit along the axial direction from the outer peripheral surface of the conductive member formed in the resin portion over the resin portion In the child manufacturing method,
When forming the resin portion, the edge that penetrates the resin bulge portion in the axial direction and is located at least on the inner diameter side forms an arc-shaped through hole ,
The slit is formed by cutting from the outer peripheral surface of the conductive member to the through hole . A method of manufacturing a commutator, wherein the slit is formed.

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