JP3628989B2 - Disc-shaped eccentric rotor and flat vibration motor having the same - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an improvement of a flat vibration motor used as a silent call means of a mobile communication device and an eccentric rotor which is a main member thereof.
[0002]
[Prior art]
Conventionally, an eccentric weight W made of tungsten alloy is arranged on the output shaft S of the cylindrical DC motor M as a silent call means such as a pager or a mobile phone, and the centrifugal force of the eccentric weight W is used during rotation as shown in FIG. In this way, vibrations are generated.
[0003]
However, in the case where the eccentric weight W is added to the conventional output shaft S, there is a design limitation such as the fact that the turning space of the eccentric weight W has to be taken into consideration on the device side such as a pager, which is expensive. Since a tungsten alloy is used, there is a problem in terms of cost.
[0004]
Recently, such a cylindrical DC motor is also required to have a thin cylinder, and those having a diameter of about 4 mm have begun to be used. However, in order to obtain the amount of vibration, even if the motor body is 4 mm, the eccentric space of the eccentric weight arranged on the output shaft is about 6 mm, and the cylindrical type cannot be placed as it is, and usually requires a mounting member. Thus, a considerable occupation space must be set, which has become a bottleneck in reducing the thickness of portable devices. Moreover, since the efficiency is in the range of 20 to 30%, there is a problem that current consumption becomes large. For this reason, flat motors that can easily ensure a thickness of 3 mm or less are being re-recognized.
The present applicant eliminates the output shaft and arranges one of the three air-core coils, which are originally normally divided into equal parts, by shifting the phase to the opposite side and biasing them, thereby making the built-in rotor itself. An eccentric flat coreless vibration motor is proposed as Japanese Patent No. 2137724 (US Pat. No. 5,036,239).
[0005]
Since the motor can take a large effective conductor length of the armature coil, the motor is relatively high in efficiency and can easily obtain power consumption of about 10 mA at 3V input. In addition, because there is no output shaft and eccentric weight, it is not subject to design restrictions, it is easy to use, and there is no risk of contact with other parts when turning, etc. Since three air-core coreless windings are provided on one side, the size of the coil has to be small, and the number of parts and the number of processing steps increase.
[0006]
[Problems to be solved by the invention]
The above-described one equipped with a built-in eccentric rotor having three air-core armature coils arranged on one side eliminates the space between the air-core armature coils as the size is reduced, and the terminal does not damage the air-core armature coil. In this way, connecting to the commutator is a difficult technique. In addition, each air-core armature coil must be smaller than the magnetic pole opening angle of the magnet, and further improvement in efficiency is desired. Further, since there are three wire-wound air-core armature coils, the number of parts increases.
Recently, with the miniaturization of mobile phones, the large amount of vibration as before is not necessarily required as a silent notification means. In addition, for the purpose of cost reduction, a three-phase system consisting of two air-core coils with one phase missing has been proposed. However, when downsizing of a diameter of 10 mm or less is required, a little more power is required. is there.
[0007]
A first object of the present invention is to obtain high efficiency and facilitate downsizing while appropriately generating vibration due to centrifugal force.
A second object of the present invention is to provide a disc-shaped eccentric rotor in which the center of gravity is shifted from the center by the coil itself and no separate eccentric member is required.
A third object of the present invention is to provide a high specific gravity weight by utilizing the thickness space of the wire wound air-core coil and further increase the vibration.
A fourth object of the present invention is to prevent axial movement of the rotor by means of printed wiring coils.
A fifth object of the present invention is to provide a cost-effective flat vibration motor with a small number of parts by using such a flat disk-shaped eccentric rotor.
[0008]
[Means for Solving the Problems]
The above basic problem solving means is provided with a shaft insertion hole in the center as in the first aspect of the present invention, a plurality of commutator segment lands are formed around the shaft insertion hole, and the outer shape is viewed from a plane. A printed wiring commutator member formed in a substantially disk shape, and at least three printed wiring air-core coils are equally formed so as not to overlap at least one surface of the printed wiring commutator member. At least one of the printed wiring coils is formed by extending the bearing holder in the axial direction at the position of the shaft insertion hole on the other surface, and unevenly distributing one or two wound-type air core coils radially outward of the bearing holder. This can be achieved with a series connection.
Specifically, as in the inventions described in claims 2 and 3, the winding type air-core coil is composed of one piece, and this winding type air-core coil is connected in series with the in-phase printed wiring air-core coil or the winding type There are two air-core coils, and this wire-wound air-core coil can be achieved by connecting them in series with in-phase printed-wire air-core coils.
As another specific means, it is preferable that the printed wiring coil is magnetically plated as in the invention shown in claim 4.
As another specific means, as in the invention shown in claim 5, an eccentric weight containing a metal is disposed at a position that does not overlap with the winding type air-core coil within a thickness of the winding-type air core coil. It is good.
Further, a spark erasing printing resistor may be disposed between the commutator segment lands as in the invention shown in claim 6.
These disc-shaped eccentric rotors include a disc-shaped eccentric rotor according to any one of claims 1 to 6 as in the inventions shown in claims 7 and 8, a shaft for supporting the eccentric rotor, and the rotor. A magnet that provides a magnetic field via an air gap in the axial direction, a brush that is arranged inside the magnet and that supplies power to the air-core coil via the flat plate commutator member, and a housing that stores these, or A flat shaft whose one end is fixed to one side of the housing, is mounted with the eccentric rotor, and the other end of the shaft is fitted in a recess disposed on the other side of the housing, thereby preventing movement in the radial direction. A vibration motor is preferable.
[0009]
According to the problem attaining means shown in claim 1 above, since each disk coil can be sized so that the effective conductor portion comes to the reference electrical opening angle that is the opening angle of the magnetic pole because of the disk shape, the efficiency is improved. By making the linear coil unevenly distributed, it can be eccentric while being in a disk shape.
Further, according to the problem attaining means described in claims 2 and 3, the center of gravity is biased by the weight difference between the printed wiring air-core coil and the wire-wound air-core coil, and vibration can be easily obtained. According to the problem attaining means described in claim 4, since unnecessary vibration in the axial direction of the rotor can be suppressed, the contact with the brush is stabilized.
According to the problem attaining means shown in claim 5, the center of gravity moves greatly in the radial direction by the weight of the wound coil and the tungsten alloy, and the amount of vibration can be increased. According to the problem attaining means shown in claim 6, sparking between the commutator and the brush can be prevented.
According to the means for accomplishing the problems shown in claims 7 and 8, since the effective conductor portion can be set to the reference electrical opening angle (opening angle of the magnetic pole) because the disk-shaped eccentric rotor makes the shape of the air-core coil, the efficiency becomes high. It can be a flat type vibration motor with less cost.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The configuration of the present invention will be described below based on each embodiment shown in the drawings.
FIG. 1 is a plan view of a printed wiring commutator member constituting a disc-shaped eccentric rotor of the present invention, as viewed from one side.
FIG. 2 is a plan view seen from the other side of the eccentric rotor using the printed wiring commutator member.
3 is a cross-sectional view taken along line AA in FIG.
FIG. 4 is a plan view showing a second embodiment of the disc-shaped eccentric rotor of the present invention. FIG. 5A is a conceptual operation explanatory diagram showing the connection state of the first embodiment.
(B) is a conceptual operation explanatory view showing the connection state of the second embodiment.
FIG. 6 is a cross-sectional view of a flat coreless vibration motor using the disc-shaped eccentric rotor of FIGS.
[0011]
In FIG. 1, reference numeral 1 denotes a printed wiring commutator member formed by forming a printed wiring board having a thickness of about 0.2 mm with copper foil formed on both sides so that the outer shape is substantially disc-shaped when viewed from the plane, and has a central axis. Six commutator segment lands a, b, c, d, which are provided with an insertion hole 1h and are short-circuited with through-holes S1, S2, etc. by using a segment facing one surface around the shaft insertion hole 1h using the other surface. e and f are formed. These opposing commutator segment lands a and d, b and e, c and f are short-circuited on the other surface via through holes S1 and S2. Three printed wiring type air-core coils 1a, 1b, and 1c having a center of approximately 90 degrees (equal to the magnetic pole opening angle of the magnet) are arranged at a pitch of 120 on the outer side. Formed equally in degrees.
The through holes S1, S2 are arranged between the three printed wiring type air-core coils 1a, 1b and 1c, and the windings of these three printed wiring type air-core coils 1a, 1b and 1c are arranged. We are careful not to sacrifice the number of times inside.
The printed wiring type air-core coils 1a, 1b, and 1c are connected through formed on the inner diameter portion by connecting the end of winding (substantially the start of winding) to the commutator segment lands a, c, and e on the drawing, respectively. As shown in FIG. 2 and FIG. 3, through the hole S3, in-phase printed wiring core coils 1aa, 1bb and 1cc, which are similarly formed on the other surface, are connected in series.
Further, the through hole S2 is directly connected to a part of the outer diameter (substantially the start of winding) of the printed wiring air-core coil.
The printed wiring air-core coils 1aa, 1bb, and 1cc cover the commutator segment portion with masking or the like and apply thin magnetic plating (not shown) on the surface. This magnetic plating has a function of attracting and attracting a magnetic field from a magnet when it is incorporated in a motor, and biasing it toward the magnet when it is made into a rotor. When the rotor is configured by this urging force, it functions to prevent unnecessary axial oscillation.
On the other surface, the printed wiring air-core coil 1aa and the winding end terminal batch connection land 1d of the 1cc are further formed on the outer peripheral portion. The winding end terminal connection land 1e of the printed wiring type air-core coil 1bb is separately formed on the outer peripheral portion.
On the other surface of the printed wiring commutator member 1, a spark erasing print resistor r1 is formed between the commutator segments by using the segment connection conductors 1f, 1g, 1i, and the like that are further opposed to each other.
On the other surface of the printed wiring commutator member 1, a bearing holder 2 made of a highly slidable resin is integrally formed in the shaft insertion hole 1h, and the bearing holder 2 is radially spaced 120 degrees apart. It has extended branch walls 2a, 2b and 2c, and is also exposed on one side.
At the position of the printed wiring type air-core coil 1bb outside the bearing holder 2, one winding-type air core coil 3 (in the figure, printed wiring coil is connected in series with the printed wiring-type air core coil 1bb). 1bb is shown as a thick solid line for convenience) and the winding start terminal 3a is soldered to the winding end terminal connection land 1e of the printed wiring type air-core coil 1bb. At the same time, the winding end terminal 3b is soldered to the terminal connection land 1ad having the same potential as the winding end terminal connection land 1d of the printed wiring air-core coil 1aa and 1cc. Notches g, h, and j are formed in each connection land provided on the outer periphery so that the terminal can be hooked so that it can be temporarily fixed at the time of soldering or thermal welding or when connecting by other means. It has become.
In the disc-shaped eccentric rotor R having such a configuration, since the center of gravity is eccentric because the winding type air-core coil 3 is unevenly distributed, a centrifugal force is generated during rotation and vibration is obtained.
Although the above can be configured as a vibration motor, in this embodiment, a heavy material, for example, an eccentric weight W made of a non-magnetic tungsten alloy is disposed at the position of the printed wiring core coil 1aa by bonding or the like. The amount of radial movement of the center of gravity is increased.
The eccentric weight may be made of a resin having a specific gravity of about 6 to 13 in which a tungsten alloy powder is mixed with the resin.
[0012]
FIG. 4 shows a second embodiment, in which a second winding type air-core coil 33 is arranged on the position of the printed-wiring air-core coil 1aa on the other surface of the printed-wiring commutator member 1, and an eccentric rotor R1 is arranged. The winding type air core coil 33 is connected in series with the printed wiring air core coil 1aa in the same phase. That is, the winding start terminal 33a is solder-connected to the winding end terminal connection land 1n of the printed wiring type air-core coil 1aa and the winding end terminal 33b is connected to the first winding type air-core coil 3 together with the winding end terminal. The end of winding of the printed wiring air-core coil 1cc is soldered to the terminal connection land 1q.
Therefore, this winding end terminal connection land 1q serves as a common connection terminal for three-phase star connection.
In this case, since the two wound air-core coils 3 and 33 are unevenly distributed, the radial movement of the center of gravity becomes large, and an eccentric weight made of an expensive tungsten alloy can be made unnecessary.
In any of the above embodiments, the six segment lands are plated with gold so that a commutator piece can be formed as it is, but the printed wiring commutator is used as a printed wiring commutator. It may be connected with
[0013]
Next, FIGS. 5A and 5B show a connection relationship of the star connection type eccentric rotor of the above embodiment and a conceptual operation explanatory diagram as a motor using the rotor. Here, a thin solid line indicates a printed wiring air-core coil, and a thick solid line indicates a wire-wound air-core coil. Since the rotation principle is well known according to Fleming's left-hand rule, the current direction and the rotation direction are indicated by arrows, and the explanation of the operation principle is omitted here. In the case of (A), torque is applied to the two coils. In the case of (B), since the negative brush straddles the segments a and b, all the coils contribute to the torque, although it is instantaneous.
[0014]
Next, in order to obtain a flat vibration motor having a disc-shaped eccentric rotor R as shown in FIGS. 2 and 3, it is preferable to use a fixed shaft type as shown in FIG. That is, an eccentric rotor R, a shaft 4 that rotatably supports the eccentric rotor R, a magnet 5 that applies a magnetic field to the eccentric rotor R through a gap, and an inner side of the magnet 5, the printed wiring commutator member 1 And a housing 9 comprising a brush 6 for supplying electric power to each of the air-core coils 1a, 1b, 1c and 3; a case 7 storing them; and a bracket 8 to which one end of the shaft 4 is fixed. Good.
Here, the other end of the shaft 4 is fitted into a recess 7a provided in the center of the case 7 via an insulating film P1, and the movement in the radial direction is restricted.
In the figure, P2 is a thrust washer made of a polyester film, and has a function of receiving good slidability when the eccentric rotor is urged toward the bracket side by the action of magnetic plating. In the figure, F is a flexible power supply lead that is soldered to the brush 6 and led out through the lower part of the magnet.
[0015]
In each of the above embodiments, the printed wiring type air-core coil is exemplified by two layers of one surface and the other surface, but a multilayer substrate in which two or three printed wiring boards having a thickness of about 0.1 mm are laminated. Alternatively, the number of turns may be increased to a printed wiring type air-core coil having 4 to 6 layers.
In addition, the printed wiring commutator member 1 has the winding-type air-core coils 3, 33, the eccentric weight W, etc. disposed by bonding, but the whole may be integrally formed with the slidable resin.
Further, the above shows a resin bearing type, but a shaft-stained oil-impregnated bearing may be housed in a shaft holder, or a bearing may be arranged in a housing and a shaft may be fixed to the eccentric rotor side.
In addition to the above, the present invention can be implemented in various other forms without departing from the technical idea or features thereof. Therefore, the above embodiment is merely an example and should not be interpreted in a limited manner.
The technical scope of the present invention is shown in the claims, and is not restricted by the text of the specification.
[0016]
【The invention's effect】
The disc-shaped eccentric rotor according to the present invention has three printed wiring type air-core coils equally arranged in three phases by enlarging the air-core coil while appropriately generating vibration due to centrifugal force as described above. According to the problem attaining means shown in the first aspect, it is possible to obtain high efficiency by combining one or two wound type air-core coils and to facilitate connection. The size of each air-core coil can be set so that the effective conductor portion comes up to a certain reference electric opening angle, so that the efficiency is high, and by making the winding coil unevenly distributed, it can be eccentric while being disk-shaped.
Further, according to the problem attaining means described in claims 2 and 3, the center of gravity is biased by the weight difference between the printed wiring air-core coil and the wire-wound air-core coil, and vibration can be easily obtained. According to the problem attaining means described in claim 4, since unnecessary vibration in the axial direction of the rotor can be suppressed, the contact with the brush is stabilized.
According to the problem attaining means shown in claim 5, the center of gravity moves greatly in the radial direction by the weight of the wound coil and the tungsten alloy, and the amount of vibration can be increased. According to the problem attaining means shown in claim 6, sparking between the commutator and the brush can be prevented.
According to the means for accomplishing the problems shown in claims 7 and 8, since the disk-shaped eccentric rotor is used, it becomes highly efficient and can be a cost-effective flat vibration motor with a small number of parts.
[Brief description of the drawings]
FIG. 1 is a plan view showing a first embodiment of a printed wiring commutator member constituting a disc-shaped eccentric rotor of the present invention as viewed from one side.
FIG. 2 is a plan view seen from the other surface side of an eccentric rotor using the printed wiring commutator member.
FIG. 3 is a cross-sectional view taken along line AA in FIG.
FIG. 4 is a plan view showing a second embodiment of the disc-shaped eccentric rotor of the present invention.
FIG. 5A is a conceptual operation explanatory diagram showing a connection state of the first embodiment.
(B) is a conceptual operation explanatory view showing a connection state of the second embodiment.
6 is a cross-sectional view of a flat coreless vibration motor using the disc-shaped eccentric rotor of FIGS. 2 and 3. FIG.
FIG. 7 is a perspective view of a conventional small vibration motor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Printed wiring commutator member 1h Shaft insertion hole a, b, c, d, e, f Commutator segment land 1a, 1b, 1c Printed wiring type air-core coil 1d, 1e, 1f, 1g Terminal connection land R of each air-core coil, R1 Disc type eccentric rotor 2 Bearing holder 2a Branch wall 3, 33 Winding type air core coil 4 Shaft 5 Magnet 6 Brush 7 Case 8 Bracket 9 Housing P1 Insulating film P2 Thrust washer r1 Spark erasing printing resistance W Eccentric weight

Claims (8)

A printed wiring commutator member having a shaft insertion hole at the center, a plurality of commutator segment lands formed around the shaft insertion hole, and having an outer shape formed substantially in a disk shape when seen from a plane, is provided. Three printed wiring air-core coils are equally formed so as not to overlap at least one surface of the member, and the bearing holder is extended in the axial direction at the position of the shaft insertion hole on the other surface of the printed wiring commutator member. A disc-shaped eccentric rotor in which one or two wire-wound air-core coils are unevenly distributed radially outward of a bearing holder and are connected in series with at least one of the printed wiring coils. 2. The disk-shaped eccentric rotor according to claim 1, wherein the winding type air-core coil is composed of one piece, and the winding-type air core coil is connected in series with a printed wiring air-core coil of the same phase. 2. The disk-shaped eccentric rotor according to claim 1, wherein the wire-wound air-core coil is composed of two, and the wire-wound air-core coils are respectively connected in series with in-phase printed wiring air-core coils. The disk-shaped eccentric rotor according to claim 1, wherein the printed wiring coil is magnetically plated. The disc-shaped eccentric rotor according to claim 1, wherein an eccentric weight including a metal is disposed within a substantially thickness of the wound air core coil at a position not overlapping with the wound air core coil. The disc-shaped eccentric rotor according to claim 1, wherein a spark erasing printing resistor is disposed between the commutator segment lands. The disc-shaped eccentric rotor according to any one of claims 1 to 6, a shaft for supporting the eccentric rotor, a magnet for applying a magnetic field to the rotor through an axial gap, and an inner side of the magnet. A flat type vibration motor comprising: a brush for supplying electric power to the air-core coil through the printed wiring commutator member; and a housing storing these. One end of the shaft is fixed to one side of the housing, the eccentric rotor is attached to the shaft from the other end, and the other end of the shaft is fitted into a recess disposed on the other side of the housing so that the shaft is radially The flat vibration motor according to claim 8, wherein the flat vibration motor is prevented from moving.

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