JP4292642B2 - Small motor with commutator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a small DC motor, and more particularly to a connection structure between a winding terminal and a commutator.
[0002]
[Prior art]
Conventionally, in connecting a winding terminal of a small DC motor to a commutator, a method by soldering or a method called fusing has been generally used. For example, fusing is described in Japanese Utility Model Publication No. 6-77475.
[0003]
The embodiment will be described with reference to FIG. In the figure, (a) is a side view of a conventional rotor, (b) is a side view of the commutator, and (c) is a side view of the commutator piece. A commutator piece 9100 constituting the commutator 9000 includes a terminal portion 9120 extending from the rectifying portion 9110. The terminal portion is provided with a first U-shaped portion 9130 and a second U-shaped portion 9140 for connecting the winding terminal 9210. Then, the winding terminal 9210 is tangled on the first U-shaped portion 9130, and the varistor 9300 is placed on the flat portion 9150 near the second U-shaped portion. Cream solder is interposed between the varistor 9300 and the flat portion 9150. In this state, when an electrode is applied to the tip 9160 of the rectifying unit and the tip 9170 of the terminal part and energized, these U-shaped parts generate heat, and soldering of the varistor 9300 and welding of the winding terminal 9210 are performed. It is.
[0004]
However, since the welding of the winding terminal only by this energization heating is low in reliability, in most cases, a method of pressing the U-shaped part in the closing direction is used together. It requires a space in which two energizing electrodes can be inserted and pressed. Therefore, this method is not suitable for a motor that is extremely small and requires high density and high output. In addition, since a considerable amount of heat is generated in the commutator, the surrounding insulating resin is easily deformed.
[0005]
Rather than this fusing method, the other soldering method is easier to apply to small precision motors. However, in the soldering connection of the terminal portion, the winding shape of the winding terminal is indefinite. Therefore, unlike soldering on a printed wiring board, it is difficult to control the amount of solder, and it is difficult to keep the connection region always small. Considering the environmental pollution problem, it is a social demand for our producers to shift to a connection method that uses less solder.
[0006]
[Problems to be solved by the invention]
One method of connecting the commutator and the winding without using this solder is a welding method. For example, Japanese Patent Application Laid-Open No. 55-23715 describes a method by arc welding. This is shown in FIG. In the figure, (a) is a side sectional view in the vicinity of a commutator of another conventional example, and (b) is a partial sectional view as viewed from the axial direction. This is an invention in medium and large motors such as engine starter motors. As shown in the figure, while holding the end 9600 of the winding on the outer peripheral surface of the commutator piece 9500 with the holding jig 9700, the welding head 9800 is brought close to the tip of the winding end to cause arc discharge and melt-connect. Yes. As described above, the arc welding method has been often used in medium and large motors.
[0007]
Since this arc welding method does not use solder, there is no concern about environmental pollution and the connection area may be reduced. However, the area around the weld becomes very hot, and at the same time spark and contamination occur. As a result, the commutator and surrounding members are altered, deformed and contaminated. This made it difficult to apply to small precision motors that must perform stable rectification at low voltage and low current.
[0008]
As described above, when connecting the commutator to the winding terminal, the commutator connection is excellent in productivity and can realize a connection area / working area equal to or less than the soldering method and fusing method, not the soldering method. A structure was desired. The arc welding method can be an alternative, but it is not suitable for ultra-small precision motors. Accordingly, it is an object of the present invention to create a joining structure suitable for a small precision motor that eliminates the disadvantages of the conventional arc welding and takes advantage of the advantages.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, a small motor according to the present invention includes a core having a plurality of wound salient poles, and a commutator having a plurality of commutator pieces placed in an axial direction with respect to the core. The commutator piece includes a rectifying portion formed in an arc shape, a radial portion extending radially outward from the rectifying portion, an electrode portion exposed in a part of the radial portion and a metal surface exposed, and a shaft extending from the radial portion. and axial portion extending beyond the thickness of the core in a direction, and a terminal portion for connecting there winding terminal end of the axial portion, and heating and melting an end portion of the front SL terminal portions preform the winding It is formed by joining with a wire terminal.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 of the present invention includes: a core having a plurality of wound salient poles; and a commutator having a plurality of commutator pieces placed in an axial direction with respect to the core. Is a rectifying portion formed in an arc shape, a radial portion extending radially outward from the rectifying portion, an electrode portion that is part of the radial portion and exposing a metal surface, and the axial direction from the radial portion. An axial portion extending beyond the thickness of the core, and a terminal portion at one end of the axial portion for connecting a winding terminal, and heating and melting the end portion of the terminal portion base material to join the winding terminal This is a small motor.
[0011]
The invention according to claim 2 of the present invention comprises: a core having a plurality of wound salient poles; and a commutator having a plurality of commutator pieces placed in an axial direction with respect to the core; Is a rectifying portion formed in an arc shape, a radial portion extending radially outward from the rectifying portion, an axial portion extending from the radial portion in the axial direction beyond the thickness of the core, and a part of the axial portion An electrode part having a metal surface exposed and a terminal part at one end of the axial part for connecting a winding terminal, and heating and melting an end part of the terminal part base material to join the winding terminal This is a small motor.
[0012]
The invention according to claim 3 of the present invention is a small motor in which a heat conduction resistance portion is further provided between the terminal portion and the rectification portion .
[0013]
The invention according to claim 4 of the present invention is a small motor in which a cross-sectional area of the winding is larger than a cross-sectional area of the terminal portion .
[0014]
The invention according to claim 5 of the present invention comprises a core having a plurality of wound salient poles, and a commutator having a plurality of commutator pieces placed in an axial direction with respect to the core, and the commutator pieces. Is a rectifying portion formed in an arc shape, a radial portion extending radially outward from the rectifying portion, an electrode portion that is part of the radial portion and exposing a metal surface, and the axial direction from the radial portion. A winding terminal connecting method for a small motor having an axial part extending beyond the thickness of a core and a terminal part at one end of the axial part for connecting a winding terminal .
[0015]
The invention according to claim 6 of the present invention includes a core having a plurality of wound salient poles, and a commutator having a plurality of commutator pieces placed in an axial direction with respect to the core, and the commutator pieces. Is a rectifying portion formed in an arc shape, a radial portion extending radially outward from the rectifying portion, an axial portion extending from the radial portion in the axial direction beyond the thickness of the core, and a part of the axial portion A winding terminal connecting method for a small motor, comprising: an electrode portion having a metal surface exposed therein; and a terminal portion at one end of the axial portion to which a winding terminal is connected, wherein the winding terminal is connected to the terminal portion. After winding, the first welding electrode is connected to the electrode part, the second welding electrode is brought close to the terminal part, arc discharge is generated, and the end part of the terminal part base material is heated and melted. The winding terminal connection of a small motor joined with the winding terminal It is a method.
[0016]
The invention according to claim 7 of the present invention is the winding terminal connection method for a small motor , further comprising bending the terminal part after the end part of the terminal part base material is heated and melted .
[0017]
The invention according to claim 8 of the present invention is also a winding terminal connection method for a small motor in which a cross-sectional area of the winding is larger than a cross-sectional area of the terminal portion .
[0018]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0019]
Example 1
FIG. 1 is a structural sectional view of a motor according to an embodiment of the present invention. 2A and 2B are explanatory views of the commutator, wherein FIG. 2A is a side sectional view, FIG. 2B is a plan view, and FIG. 2C is a front view in the vicinity of a terminal portion. FIG. 3 shows the rotor in which the commutator is incorporated, undergoes a winding process, and is in a state before the welding process, (a) is a plan view thereof, (b) is a side cross-sectional view, and (c) is near the terminal portion. FIG. FIG. 4 is a schematic diagram showing the welding process, FIG. 5A is a partial enlarged cross-sectional view of the terminal portion before welding, and FIG.
[0020]
In FIG. 1, the motor is composed of a rotor 1001 (entire rotating part) and a stator (non-rotating part whole). The stator includes a frame 5100, a magnet 5200, an upper bearing 5300, a lower bearing 5400, a bracket 5500, a brush 5600, a brush base 5700, a brush holder 5800, and the like. On the other hand, the rotor 1001 includes a shaft 1101, a core 1201, insulators 1301, 1401, a winding 1501, a commutator 2001, and the like.
[0021]
Since the present invention relates to a method for manufacturing a rotor, the structure of the rotor 1001 will be described. First, as illustrated in FIG. 2, the commutator 2001 includes a base 2101, a commutator piece 2201, and an insulating washer 2301. Three commutator pieces 2201 are attached to a base 2101 made of synthetic resin, and the outer periphery of the commutator piece 2201 is held by an insulating washer 2301. The insulating washer 2301 is a heat-resistant synthetic resin that does not lose its holding power even at high temperatures. The commutator piece 2201 includes a rectifying part 2211 formed in an arc shape, a radial part 2221 extending radially outward from the rectifying part, an electrode part 2231 that is part of the radial part and exposing a metal surface, and a radial part It has an axial portion 2241 that extends in the axial direction beyond the thickness of the core, and a terminal portion 2251 that is at one end of the axial portion and connects the winding terminal. Further, a constricted portion 2261 as a heat conduction resistance portion is formed in a part of the axial portion. The commutator piece 2201 is made of a copper-based alloy, but the rectifying unit 2211 has a material and a surface state that maintain stable slidability and conductivity over a long period of time.
[0022]
Using this commutator, a rotor 1001 is assembled as shown in FIG. The insulators 1301 and 1401 are attached to the shaft 1101 and the core 1201 fixed to each other, and the commutator 2001 is attached. Then, the winding 1501 is performed. In the winding process, the winding terminal 1511 is wound around the terminal portion 2251 of the commutator a plurality of times while being wound around the convex pole of the core 1201. This terminal portion 2251 has a cross-sectional area much larger than that of the winding material for winding the winding terminal. In the figure, reference numeral 2231 denotes an electrode portion, 2241 denotes an axial portion, and 2301 denotes an insulating washer. After the above is completed, the process proceeds to the next bonding step.
[0023]
FIG. 4 is a schematic view of a welding apparatus. The rotor 1001 described above is placed on the positioning table 7101 in the posture shown in the figure. When the start switch is pressed, the work clamper 7201 descends and holds the tip of the shaft 1101. Next, the welding electrode 7301 of the welding apparatus rises and contacts the electrode portion 2231 of the commutator piece. Further, the welding head 7401 approaches the vicinity of the tip of the terminal portion 2251 from obliquely above. This welding head 7401 is a non-consumable electrode using tungsten or the like. The electrode has a tip viewed from the center of the gas nozzle 7501. The gas 7600 to be ejected is an inert gas such as argon, and encloses the periphery of the terminal portion 2251 which is a welding base material in an inert gas atmosphere. The apparatus of the system called what is called TIG welding is comprised. In this state, arc discharge is performed, and the tip of the terminal portion 2251 is melted instantaneously. Then, the winding terminal 1511 around which the molten base material is wound is wrapped in a spherical shape, and the joining is completed.
[0024]
FIG. 5 is a schematic cross-sectional view showing details of the welded joint made in this way. (A) shows the terminal part before welding, (b) shows the terminal part after welding. In this manner, the end portion of the base material of the terminal portion 2251 is heated and melted into a spherical shape, and the wound winding terminal 1511 is wrapped and joined. In this embodiment, the terminal portion 2251 that has been joined by the welding device is bent outward in the radial direction as shown in FIG. Then, the rotor 1001 is incorporated to complete the motor as shown in the figure.
[0025]
As described above, in the motor of this embodiment, arc welding is adopted for connection between the terminal portion 2251 of the commutator and the winding terminal 1511. This method can be connected by heating and melting a minute region at the tip of the terminal base material. The amount of melting of the base material can be easily controlled by adjusting the discharge energy. Since the connection can be made in a narrow area smaller than the solder connection, the joining area can be made small and the motor can be adapted to a small and high density design of the motor. Further, in this method, heat welding by arc discharge can be performed only by bringing the welding head 7401 close to each other and blowing an arc. It is suitable for work in a narrow area where cores, windings, etc. are close to each other with high density and a fusing equipment cannot be inserted. Therefore, the work area can be reduced and the motor can be adapted to a small and high density design of the motor.
[0026]
Further, in the motor of this embodiment, the winding terminal is wound a plurality of times around the terminal portion having a much larger cross-sectional area than the winding, and the terminal portion is melted and joined so as to wrap the winding. It is suitable for small motors that do not use thick windings, such as medium and large motors.
[0027]
In the motor of this embodiment, the electrode portion 2231 is disposed between the rectifying portion 2211 and the terminal portion 2251. And since it enabled it to supply between the electrode part 2231 and the terminal part 2251, it can avoid that welding current passes the rectification | straightening part 2211. FIG. Therefore, it is possible to join without adversely affecting the composition and accuracy of the rectifying unit 2211, and a high-quality motor can be obtained.
[0028]
Medium and large motors handle large currents, so some deterioration and contamination on the surface of the rectifier has little effect on performance, but it is a major problem in precision small motors. When a welding electrode is connected to the surface of the rectifying unit with a small motor having a conventional configuration that does not consider arc welding, adverse effects such as melting, deformation, and contamination of the surface of the commutator could not be prevented. In addition, the method applied to the vicinity of the end face of the rectification unit as in the fusing example given at the beginning could not completely eliminate the contamination of the commutator surface due to the spark even though the degree of influence decreased. According to the present invention, such problems can be solved and good quality can be maintained.
[0029]
Further, in the motor of this embodiment, the electrode portion 2231 is disposed on the outer peripheral side of the insulating washer 2301. A spark may occur between the electrode portion 2231 and the welding electrode 7301, but even in that case, the outer peripheral wall portion of the insulating washer 2301 is blocked and the contaminant does not reach the rectifying portion 2211. This contributes to maintaining good quality. By the way, arc welding is performed while injecting an inert gas toward the terminal portion, and pollutants are mixed in the exhaust gas. Therefore, it is better to avoid the exhaust going to the rectification unit. Although not shown, it is preferable to wrap the entire rectifying unit with a pipe-shaped cover, for example, so that the inside is kept at a positive pressure.
[0030]
In the motor of this embodiment, the electrode portion 2231 is disposed on the end surface in the axial direction of the portion excluding the rectifying portion. Since it did in this way, an apparatus can be comprised so that it may connect with the welding electrode of a welding apparatus only by mounting a rotor on the positioning stand 7101 perpendicularly to an axial direction. Therefore, work can be carried out at high speed and reliably, and high quality and high productivity can be realized.
[0031]
In the motor of this embodiment, the commutator piece 2201 includes a radial portion 2221 extending radially outward from the rectifying portion 2211, an electrode portion 2231 that is part of the radial portion and exposing a metal surface, and a radial portion. The structure has a terminal portion 2251 that extends and connects the winding terminal. The arrangement of the electrode part between the rectification part and the terminal part and the arrangement at a position accessible from the axial direction are simultaneously satisfied.
[0032]
In addition, the motor of this embodiment includes an axial portion 2241 that extends from the radial portion 2221 in the axial direction beyond the thickness of the core 1201 and a terminal portion 2251 that is connected to a winding terminal at one end of the axial portion. Since the distance from the rectifying unit to the terminal unit is kept large, the heat when welding the terminal unit 2251 is less transmitted to the rectifying unit 2211, and a high-quality motor can be obtained. At the same time, since the electrode portion 2231 and the terminal portion 2251 are separated on both sides in the axial direction with the core 1201 interposed therebetween, for example, the welding electrode 7301 can be disposed on the lower side and the welding head 7401 can be disposed on the upper side. That is, the design of the welding apparatus becomes easy and high quality and high productivity can be realized. Unlike medium and large motors, arc welding must be performed in a very small space, but the workability has been greatly improved.
[0033]
Further, in the motor of this embodiment, a heat conduction resistance portion 2261 is provided between the terminal portion 2251 and the rectifying portion 2211, thereby preventing heat due to welding heating from being transmitted to the rectifying portion. It is even less likely to transfer heat to the rectifying unit when the terminal part is heat-welded, and a high-quality motor can be obtained.
[0034]
Here, the terminal portion preferably has a shape that extends linearly so that the welding head can be brought close to each other accurately so that the winding terminal can be wound a plurality of times. Since the proximity distance is a parameter that affects the discharge energy, it is important to improve the proximity accuracy. Furthermore, it is desirable to extend the direction in the axial direction because winding is easy, but when a low profile is required, the direction may be the outer circumferential direction. Moreover, you may bend the terminal part in the outer peripheral direction or the inner peripheral direction after completion of welding. It is simple in manufacturing that the heat conduction resistance portion has a structure in which the cross-sectional area is reduced from the vicinity thereof as in this embodiment. If it does so, it can also serve as a bending point at the time of bending.
[0035]
(Example 2)
Another embodiment of the present invention will be described with reference to FIG. In the figure, 7102 and 7202 are work clampers, 1512 is a winding terminal, 2252 is a terminal portion, 7402 is a welding head, and 7502 is a gas nozzle. In the figure, 7102 and 7202 are work clampers, 1512 is a winding terminal, 2252 is a terminal portion, 7402 is a welding head, and 7502 is gas noise. In the rotor 1002 shown in FIG. 6, a part of the axial portion 2242 of the commutator piece 2202 is exposed to form an electrode portion 2232, and the welding electrode 7302 is brought into contact with the outer peripheral side. Depending on the shape of the motor, it may not be possible to provide the electrode portion on the end face in the axial direction, which is effective in such a case.
[0036]
(Example 3)
Still another embodiment will be described with reference to FIG. In the figure, 7103 is a work clamper, 7303 is a welding electrode, 2233 is an electrode portion, 1513 is a terminal winding, 7403 is a welding head, and 7503 is a gas nozzle. In FIG. 7, the commutator piece 2203 has a rectifying portion 2213, a radial portion 2223, an electrode portion 2233 that is a part of the rectifying portion 2213, and a terminal portion 2253. The terminal portion 2253 extends from the radial portion 2223 in the outer peripheral direction and extends at a certain angle in the axial direction. According to such a structure, depending on the case, it is not necessary to bend the terminal portion after joining as in the first embodiment, and the rotor can be designed so that the terminal portion does not get in the way during the winding operation. Of course, if there is no hindrance to the winding work, it is not necessary to make an angle in the axial direction.
[0037]
Although several embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various applications can be made within the scope of the present invention.
[0038]
【The invention's effect】
As described above, the present invention can be connected in a narrow region smaller than the soldering connection by providing a terminal on the commutator and winding the winding terminal to perform arc welding, and can also work in a region narrower than the fusing method. I was able to do it. Further, since the electrode portion is disposed between the rectifying portion and the terminal portion, it is possible to avoid the welding current from passing through the rectifying portion, and the quality is not deteriorated. Furthermore, since the electrode portion is disposed on the end surface in the axial direction of the portion excluding the rectifying portion, it can be connected to the welding electrode of the welding apparatus simply by placing the rotor on the jig.
[0039]
Therefore, it is suitable for an ultra-small precision motor, and can realize a commutator connection structure that can realize a connection area equal to or less than the soldering method, and is excellent in productivity, and a motor including the same.
[Brief description of the drawings]
FIG. 1 is a structural cross-sectional view of a motor according to an embodiment of the present invention. FIG. 2A is a side cross-sectional view of a commutator. FIG. 1C is a plan view of the commutator. a) Plan view of the rotor in the state before the welding process (b) Cross-sectional view of the same side (c) Front view of the vicinity of the terminal part [FIG. 4] Schematic diagram showing the welding process [FIG. 5] (a) Before welding (B) Partial enlarged sectional view of the terminal portion after welding FIG. 6 is a schematic view of a rotor and welding according to another embodiment of the present invention. FIG. 7 is still another embodiment of the present invention. FIG. 8 (a) Side view of a conventional rotor (b) Side view of the commutator (c) Side view of the commutator piece [a] FIG. ) Side sectional view of the commutator near another conventional example (b) Partial sectional view of the commutator viewed from the axial direction
1001, 1002, 1003 Rotor 1101 Shaft 1201 Core 1301, 1401 Insulator 1501 Winding 1511, 1512, 1513 Winding terminal 2001 Commutator 2101 Base 2201, 2202, 2203 Commutator piece 2211, 2213 Commutator 2221, 2223 Radial part 2231, 2232, 2233 Electrode part 2241, 2242 Axial part 2251, 2252, 2253 Terminal part 2261 Constriction part (thermal conduction resistance part)
2301 Insulating washers 7101, 7102, 7103 Positioning bases 7201, 7202 Work clampers 7301, 7302, 7303 Welding electrodes (first welding electrode, ground electrode)
7401, 7402, 7403 Welding head (second welding electrode)
7501, 7502, 7503 Gas nozzle 7600 Inert gas

Claims (8)

A core having a plurality of salient poles wound, and a commutator having a plurality of commutator pieces placed in an axial direction with respect to the core, the commutator pieces being formed in an arc shape; A radial portion extending radially outward from the rectifying portion, an electrode portion having a metal surface exposed at a part of the radial portion, and an axial portion extending beyond the thickness of the core in the axial direction from the radial portion the and a terminal portion for connecting there winding terminals at one end of the axial portion, front Symbol ends melted by heating small motor formed by joining with the winding terminal of the terminal unit matrix. A core having a plurality of wound salient poles, and a commutator having a plurality of commutator pieces placed in an axial direction with respect to the core, the commutator pieces being formed in an arc shape; and A radial portion extending radially outward from the rectifying portion; an axial portion extending from the radial portion in the axial direction beyond the thickness of the core; and an electrode portion exposed at a part of the axial portion and having a metal surface exposed A small motor having a terminal portion at one end of the axial portion and connecting a winding terminal, and heating and melting the end portion of the terminal portion base material to join the winding terminal. Small motor according to claim 1 or claim 2 provided with a thermal resistivity portion between said terminal portion and the rectifying portion. The small motor according to any one of claims 1 to 3, wherein a cross-sectional area of the winding is larger than a cross-sectional area of the terminal portion. A core having a plurality of salient poles wound, and a commutator having a plurality of commutator pieces placed in an axial direction with respect to the core, the commutator pieces being formed in an arc shape; A radial portion extending radially outward from the rectifying portion, an electrode portion having a metal surface exposed at a part of the radial portion, and an axial portion extending beyond the thickness of the core in the axial direction from the radial portion A method of connecting a winding terminal of a small motor having a terminal part at one end of the axial part for connecting a winding terminal,
After winding the end of the winding around the terminal part , the first welding electrode is connected to the electrode part, the second welding electrode is brought close to the terminal part, and arc discharge is generated, and the terminal A method for connecting a winding terminal of a small motor, comprising heating and melting an end portion of a base material and joining to the winding terminal. A core having a plurality of wound salient poles, and a commutator having a plurality of commutator pieces placed in an axial direction with respect to the core, the commutator pieces being formed in an arc shape; and A radial portion extending radially outward from the rectifying portion; an axial portion extending from the radial portion in the axial direction beyond the thickness of the core; and an electrode portion exposed at a part of the axial portion and having a metal surface exposed A method for connecting a winding terminal of a small motor having a terminal part at one end of the axial part for connecting a winding terminal,
  After winding the end of the winding around the terminal portion, the first welding electrode is connected to the electrode portion, the second welding electrode is brought close to the terminal portion, and arc discharge is generated, and the terminal A winding terminal connecting method for a small motor, wherein the end portion of the base metal is heated and melted and joined to the winding terminal. The method for connecting a winding terminal of a small motor according to claim 5 or 6, wherein the terminal portion is bent down after the end portion of the terminal portion base material is heated and melted. The winding terminal connection method of the small motor according to any one of claims 5 to 7, wherein a cross-sectional area of the winding is larger than a cross-sectional area of the terminal portion.

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