JPH09233764A - Vibrating motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor which can generate vibration even at a low speed rotation and has little vibration damping ratio. SOLUTION: This motor is provided with an eccentric rotor 3 supported so as to rotate in a casing, consisting of a cup-shaped case 1 and a bottom plate for covering the opening of the case 1, and produces vibration as a result of the eccentric rotor rotating. The eccentric rotor 3 involves a coil 4 with a plurality of phases, and a frame 5 which restrains the coil 4 and where a position out of its center of gravity is the center of rotation, and the frame 5 is constituted of magnetic metal. The eccentric rotor 3 involves a flat-shaped commutator 6. The first terminal of the coil 4 with a plurality of phases is connected to the respective segments of the commutator 6. The second terminal of the coil 4 of a plurality of phases is common-connected to the frame 5, and respective coils 4 may be star-connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration motor in which a plurality of air-core coils are eccentrically arranged on one side of a rotor. For example, an individual call signal is transmitted to a personal handyphone (PHS). It can be used for the purpose of notifying the reception by generating vibration.

[0002]

2. Description of the Related Art In a mobile phone or the like, a vibration motor for generating vibration by rotation may be used as one of means for informing that an individual call signal has been received. In order to generate vibration due to the rotation of the motor, an eccentric plate with a decentered center of gravity may be provided on the output shaft of the motor, but in order to reduce the thickness and reduce the current consumption, a plurality of drive coils are installed in the rotor. It is proposed to displace it on one side of. An example is the one described in Japanese Utility Model Laid-Open No. 2-33573, which is shown in FIGS. 10 and 11.

In FIGS. 10 and 11, the vibration motor is press-fitted and fixed in a cup-shaped case 36, an end plate 31 covering the open end of the case 36, and the center holes of the case 36 and the end plate 31. Oil-impregnated bearings 32 and 35, a rotary shaft 33 rotatably supported by the oil-impregnated bearings 32 and 35, a boss 34 integrally provided on the rotary shaft 33 between the oil-impregnated bearings 32 and 35, and a boss 34 of the boss 34. A rotor holder 21 integrally formed with resin on the outer peripheral side, and three drive coils 23 embedded in the rotor holder 21.
A flat commutator 38 provided on the lower surface side of the rotor holder 21, and a brush 37 slidably contacting the flat commutator 38.
And a flat ring-shaped magnet 39 fixed to the inner surface of the end plate 31 so as to face the drive coil 23. The three drive coils 23 are arranged on the rotor holder 21 so as to be offset from the rotation shaft 33, and when the rotor 30 is rotationally driven, vibration is generated due to an imbalance in weight thereof. Commutator 38 and brush 37
The drive coils 23 are energized via the
The rotor 30 can be continuously driven to rotate by switching the energization of each drive coil 23 according to the rotational position of. When the rotor 30 is rotationally driven, the vibration is generated as described above.

According to the conventional flat type vibration motor described above, by arranging the plurality of drive coils 23 in the rotor holder 21 in a biased manner, the center of gravity is moved to one side and the rotor itself is unbalanced to generate vibration. Therefore, it is not necessary to newly add a component for unbalanced weight distribution of the rotor, and it is possible to obtain a highly efficient vibration motor that is thin and consumes less current.

[0005]

However, in the vibration motor having the above structure, the rotor 30 including the drive coil 23 and the rotor holder 21 is formed by molding the drive coil 23 with resin. For this reason,
The rotor 30 itself is light in weight, the amount of eccentricity, that is, the amount of imbalance is small, and the rotor 30 rotates at high speed (4000 rpm to 7000 r).
If it is not performed, a predetermined amount of vibration cannot be generated. Further, since the rotor 30 itself is light in weight, the load is reduced, and even if the number of rotations is increased and the amount of vibration is increased, the vibration damping ratio (vibration down ratio) at the time of motor assembly is increased. Had a point.

The present invention has been made in order to solve the problems of the prior art as described above, and provides a vibration motor that can generate vibration even at low speed rotation and has a small vibration damping rate. With the goal.

[0007]

According to the first aspect of the present invention,
A vibration motor comprising an eccentric rotor rotatably supported in a casing formed of a cup-shaped case and a bottom plate covering an opening of the case, wherein the eccentric rotor causes vibration to occur. Multi-phase coils,
It has a frame which holds the coil and is a center of rotation at a position deviated from the center of gravity, and the frame is made of a conductive metal.

According to a second aspect of the present invention, the eccentric rotor has a flat plate-shaped commutator, and the first terminals of the coils of the plurality of phases are connected to different segments of the commutator, respectively, while the first terminals of the coils of the plurality of phases are connected. The second terminal is commonly connected to the frame, and each coil is star-connected.

According to a third aspect of the present invention, a cylindrical portion integrally provided with the frame holds the bearing by a bearing, the bearing is inserted into a shaft fixed in a casing, and the eccentric rotor is rotatably supported. It is characterized by being

The invention according to claim 4 is characterized in that an arc-shaped collar portion is provided on the outer peripheral edge of the frame.

By energizing the air-core coil held by the eccentric frame composed of the integrally formed holding part and bearing, the eccentric rotor composed of the air-core coil, the eccentric frame, etc. is rotationally driven. Since the eccentric frame is made of conductive metal and the weight distribution is unbalanced,
The rotation causes vibration.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a flat type vibration motor according to the present invention will be described below with reference to the drawings. 1 to 3, a hole 2a is formed in the center of the bottom plate 2.
The shaft 9 is press-fitted and fixed in the hole 2a. Further, a flat ring-shaped drive magnet 7 is attached to a portion of the bottom plate 2 on the outer peripheral side of the shaft 9.

A sintered oil-impregnated type bearing 8 is provided on the outer peripheral surface of the shaft 9.
The inner peripheral surface of is inserted. A frame 5 formed by pressing or forging a conductive metal is attached to the outer peripheral surface of the bearing 8. Frame 5 is
The outer diameter is substantially semicircular, and a cylindrical boss portion 5c is integrally formed at a position deviated from the center of gravity of the holding portion 5d, and the inner peripheral surface of the boss portion 5c is relative to the outer peripheral surface of the bearing 8. Pressed and fixed. In addition, three triangular holes 5b, 5b ', and 5 are provided at concentric circles with the boss 5c as the center.
b "is formed. The holes 5b, 5b ', 5b" are
The portions adjacent to each other are cut out to form soldered portions A and A '. Further, at the outer edge portion of the frame 5 on a concentric circle centered on the boss portion 5c, the collar portion 5 protruding toward the bottom plate 2 side is formed.
a is formed.

Further, the holes 5b, 5b 'and 5b "formed in the holding portion 5d of the frame 5 have coils 4w, 4v,
4u are attached respectively. Coils 4w, 4
Reference symbols v and 4u are air-core coils having a hole in the center, and the insulating phase is peeled off at the inner peripheral surface of the hole and at the portion closest to the boss 5c to form the electrodes 4w1, 4v1, and 4u1. . Further, no insulating layer is formed on the outer peripheral surfaces of the coil 4w, the coil 4v, and the coil 4u, and the conductive portions are exposed. Of these, the portion of the outer peripheral surface of the coil 4w that faces the coil 4v in the soldering portion A is the electrode 4w2. In addition, coil 4
coil 4u on the outer peripheral surface of v and in the soldering portion A '.
The portion facing each other with a constant gap is the electrode 4v2. Further, in the coil 4u, the soldered portion A
The portion facing the electrode 4v2 is the electrode 4u2. The electrodes 4w2, 4v2, 4u2 are the second terminals of the coils 4w, 4v, 4u, and are soldered in the soldering portions A and A ', respectively, so that the electrodes 4w2, 4v2, 4u2 are connected to each other via the frame 5 made of a conductive metal. It is in the form of common connection. Each coil 4w, 4v, 4u is W
It belongs to phase, V phase, and U phase, and has a three-phase configuration.

A plane commutator 6 is attached to the outer peripheral surface of the boss portion 5c of the frame 5. An inner peripheral side portion of the upper end surface of the plane commutator 6 is in contact with the lower end surface of the frame 5. Further, the outer peripheral side portion of the upper end surface of the plane commutator 6 covers the holes 5b, 5b ', 5b "from below. In the holes 5b, 5b', 5b" of the plane commutator 6, Terminals X, Y and Z are formed on the covered portion. These terminals X, Y and Z are placed in the coil 5 in the holes 5b, 5b 'and 5b ".
When w, 4v, 4u are attached, electrodes 4w1, 4v
It is formed at a position corresponding to 1, 4u1. Therefore, the holes 5b, 5b 'of the coils 4w, 4v, 4u,
Electrodes 4w1, 4v1, 4 at the same time as mounting to 5b "
The u1 and the electrodes X, Y, Z can be connected by soldering. In addition, the holes 5b, 5 of the flat commutator 6 are
The coil 4w, by the portion covered in b ', 5b ",
4v and 4u are supported without dropping downward from the holes 5b, 5b ', and 5b ".

On the lower end surface of the plane commutator 6, nine fan-shaped segments are formed concentrically around the boss portion 5c. As shown in Figure 2, the segments are clockwise,
The segment U1, the segment V1, the segment W1, the segment U2, the segment V2, the segment W2, the segment U3, the segment V3, and the segment W3 are formed in this order. Of these, segments U1, U2, U3
Are connected to each other by patterns, through holes, etc. formed on the bottom plate 2 side of the commutator 6. In addition, the segments V1, V2, V3 or the segments W1, W
Similarly, 2 and W3 are connected to each other by a pattern formed on the bottom plate 2 side of the commutator 6 or through holes. Further, the terminal X connected to the electrode 4w1 of the coil 4w is the segment W3, and the terminal Y connected to the electrode 4v1 of the coil 4v is the segment v1 and the electrode 4 of the coil 4u.
The terminal Z connected to u1 is connected to the segment u2 by a through hole or the like. Therefore, the coil 4w,
4v and 4u are common-connected electrodes 4w1 and 4v1,
4u1 and electrodes 4w2, 4v2, 4u2, etc. connected to the segments of the plane commutator 6 are in a star-connected form.

Of the segments (U1 to W3) formed on the lower surface of the plane commutator 6, the coils 4u, 4v, 4w are energized via brushes (not shown) which are in sliding contact with specific segments corresponding to the rotational position of the rotor. Then, the driving magnet 7 biases the coils 4u, 4v, and 4w, and the eccentric rotor 3 including the frame 5 and the coils 4u, 4v, and 4w is rotationally driven, and vibration is generated due to unbalance of the weight of the eccentric rotor 3. It is supposed to do. Further, as the eccentric rotor 3 is driven to rotate, the segments with which brushes (not shown) are in sliding contact are sequentially switched. As a result, the eccentric rotor 3 is driven to rotate continuously, and vibration due to the imbalance of the weight of the frame 5 is continuously generated. To be done.

A flat cup-shaped case 1 is attached to the upper end of the shaft 9. The lower end of the peripheral wall of the case 1 is
It is attached to the outer circumference of the bottom plate 2. For this reason,
The case 1 has a configuration in which a stator member such as the driving magnet 7 attached to the frame 5 and the bottom plate 2 is covered from above, and the stator member such as the driving magnet 7 is housed inside the case 1. There is.

According to the vibration motor having the above structure, since the frame 5 is made of the conductive metal, the weight can be increased. Therefore, the amount of imbalance in weight can be increased, and vibration with a small damping rate can be generated. Further, since the weight of the frame 5 can be increased, a sufficient amount of vibration can be obtained even at low speed rotation. Further, by forming the collar portion 5a on the outer periphery of the frame 5, the weight of the frame 5 can be further increased, so that the above effect can be further enhanced. Furthermore, when the coils 4w, 4v, and 4u are star-connected, the frame 4 made of a conductive metal is used to form the coil 4
Since w, 4v and 4u can be connected in common, coil 4w,
It is possible to simplify the connection of 4v and 4u and reduce the assembly cost.

Further, in the frame 5, the coils 4w, 4v, 4
Although u is commonly connected, a current at that time can be passed to the shaft 9 through the bearing 8 and contributes to reduction of electrical noise, that is, sparks of the segments of the plane commutator 6 and a brush (not shown). You can

The frame 5 may be made of any material as long as it is a conductive metal, and the same effect as that of the above embodiment can be obtained. Further, the frame 5 may be formed by sintering a powdery conductive metal, and the same effect as that of the above-described embodiment can be obtained. When the frame 5 is sintered with powdered conductive metal, not only the frame 5 but also the bearing 8 may be formed by sintering powdered conductive metal.

Further, in the frame 5 made of a conductive metal, the collar portion 5a for increasing the weight of the frame 5 and increasing the amount of unbalance is, as shown in FIG. Although it is formed so as to project to the side, it is not limited to this. For example, when the frame 5 is formed by sintering,
Since the degree of freedom of the shape is increased, as shown in FIG. 4B, the collar portion 5a is projected to both sides in the axial direction, that is, not only on the bottom plate 2 side but also on the opposite side, so that the collar portion 5a is protruded. Can be formed. By forming such a collar portion 5a, the weight of the collar portion 5a is increased, so that the unbalance amount can be further increased.

Further, when the frame 5 is formed by pressing or forging a conductive metal plate, as shown in FIG.
As shown in (c), the collar portion 5a may be formed by folding back the outer peripheral portion. The tip of the collar portion 5a is
It may be flush with the base of the frame 5, or
As indicated by the dotted line, the frame 5 may be projected above the base.

Further, in the above-described embodiment, the frame 5 having a substantially semicircular outer diameter is used. However, it is not limited to this. As shown in FIG. 5, a circular frame 10 may be used. The frame 10 has a circular shape, and a rotating shaft 13 is attached to the center of the circle. In addition, the rotating shaft 13 is provided on the frame 10.
Three solder circular coils 12 are attached at an equal angle (120 °) with respect to. On the other hand, on the outer periphery of the frame 5, a weight 11 made of copper and having a partial arc shape is attached. The weight 11 is attached in such a manner that the inner peripheral portion thereof extends along the outer periphery of the frame 10, and the opening angle of the circular arc centering on the rotating shaft 13 is 180.
It is set to be within °. By attaching the weights 11 to the circular frame 10 as described above, the center of gravity of the frame 10 is displaced (eccentric) from the portion where the rotary shaft 13 is attached, and the unbalance amount of the rotor weight increases. It is possible to obtain a sufficient amount of vibration even at low speed. The weight 11
Is configured as a separate component from the frame 10 and the weight 11 is attached to the frame 10. However, the present invention is not limited to this, and the frame 10 and the weight 11 may be integrally molded. Good. Frame 10
However, when the conductive metal plate is formed by pressing or forging, the weight 11 may have a brim shape so as to project to one side in the axial direction as shown in FIG. It may be shaped so as to project in the axial direction by folding back as shown in FIG. 4 (c). Further, when the frame 10 is sintered and formed, the weight 11 may be shaped so as to project to both sides in the axial direction, as shown in FIG. In any case, the center of gravity of the frame 10 can be shifted, the unbalance amount of the rotor can be increased, and a sufficient amount of vibration can be obtained during rotation.

As the rotor of the vibration motor, there is also a cylindrical one to which a cylindrical coil is attached. As the cylindrical coil, a hexagonal winding (Kodak method) as shown in FIG. 6 (a), a rhombus winding (Maxon method) as shown in FIG. 6 (b), and FIG. 6 (c) are mainly shown. There are three types of honeycomb winding (foul-faber method). Further, as shown in FIG. 6 (d), there is also one in which the air-core coil 15 is provided on the surface of a cylindrical holding member.

The inner peripheral surface of each of the various cylindrical coils 14 as described above is attached to the outer peripheral surface of the rotor. Figure 7
In (a), the rotor 15 includes a cylindrical frame 15c made of a conductive metal, a beam 15a, a coil 14, a rotating shaft 16, a weight 15b, and the like. Rotary axis 1
A cross-shaped beam 15a is provided on the outer periphery of 6, and an inner peripheral surface of a cylindrical frame 15c is attached to an outer portion of the beam 15a. Furthermore, the frame 15c
The inner peripheral surface of the coil 14 is attached to the outer peripheral surface of the coil.

The beam 15a equally divides the inner circumference of the frame 15c into four spaces. A partial arcuate weight 15b is attached to a specific space of the four spaces divided by the beam 15a so as to be along the inner peripheral surface of the frame 15c. By attaching the weight 15b, the center of rotation of the rotor 15, that is, the portion of the rotary shaft 16 and the center of gravity of the rotor 15 are displaced.
Further, since the frame 15c is made of a conductive metal, it has a sufficient weight, and large vibration can be generated even if the rotation speed of the rotor 15 is low.

Further, another embodiment of the cylindrical rotor will be described. In FIG. 7B, the rotor 17
Is composed of members such as the rotating shaft 16, the frame 17c, and the coil 14. The frame 17c is made of a conductive metal, is cylindrical, and has openings on both sides, and circular plate members 17b and 17b 'are attached to both openings. By attaching the circular plate members 17b and 17b 'to the openings on both sides of the frame 17c, the internal space of the frame 17c is sealed. In this closed space, the inner peripheral surface of the frame 17c is
A weight 17a having a partially arcuate shape and having an opening angle set within 180 ° about the rotation shaft 16 is attached along the inner peripheral surface of the frame 17c. Further, a hole is formed in the center of the plate members 17b and 17b ', and the rotary shaft 16 is passed through and fixed to the hole. Further, the inner peripheral surface of the cylindrical coil 14 is attached to the outer peripheral surface of the cylindrical frame 17c.
In such a rotor 17, the upper end portion and the lower end portion of the rotating shaft 16 are supported by bearings (not shown) and are rotationally driven.

According to the rotor 17 of the vibration motor as described above, since the weight 17a having a partial arc shape is provided on the inner peripheral surface of the rotor 17, that is, the inner peripheral surface of the frame 17c, the center of rotation of the rotor 17 And the center of gravity will shift.
Further, since the frame 17c is made of a conductive metal and has a sufficient weight, the vibration motor using the rotor 17 can generate a sufficiently large vibration even at low speed rotation.

Further, another embodiment of the rotor to which the cylindrical coil is attached will be described. FIG. 8 (a)
In (b), the rotor 18 is composed of members such as the rotating shaft 16, the frame 50, the coil 14, and the weight 19. Of these, the frame 50 is made of conductive metal,
In addition, circular plate members 51, 51 are attached to the opening portions on both sides of the cylindrical portion. Two plates 5
A hole is formed in the center of each of the holes 1, 51, and one rotary shaft 16 is passed through and fixed to the two holes. A cylindrical coil 14 is attached to the outer peripheral surface of the frame 50. The outer peripheral surface of the coil 14 does not cover the entire outer peripheral surface of the frame 50, but covers only the axially central portion of the outer peripheral surface of the frame 50. Also, the coil 14
Are opposed to the inner peripheral surface of the ring-shaped drive magnet 53 located on the outer peripheral side with a constant gap. Further, the weight 1 is attached to the upper and lower end portions of the outer peripheral surface of the frame 50 and the portions not covered with the coil 14.
9 and 19 are attached. The weights 19 and 19 have a partial arc shape with an opening angle of 180 ° or less,
Is attached so as to follow the outer peripheral surface of the. In such a rotor 18, an upper end portion and a lower end portion of the rotary shaft 16 are supported by bearings (not shown) and are rotatable with respect to a stator (not shown). Therefore, coil 1
The coil 14 is biased by the driving magnet 53 and the rotor 18 is rotationally driven by controlling the energization of the coil 4.

According to the rotor 18 of the vibration motor as described above, since the weights 19 and 19 having the partial arc shape are provided on the inner peripheral surface of the rotor 17, that is, the outer peripheral surface of the frame 50, the rotation of the rotor 18 is prevented. The center of gravity will deviate from the center of gravity. Further, the frame 17c is made of a conductive metal and has a sufficient weight, and since two weights 19 are used, a large vibration can be generated even at low speed rotation.

Both weights 19 are frame 5
It may be attached only to the outer peripheral surface on the upper side of 0, or may be attached only to the outer peripheral surface on the lower side. However, if the weights 19 are attached so that the inner peripheral surfaces of the weights 19 face each other with the rotation axis 16 as the center, the center of rotation of the rotor 17 and the center of gravity coincide, so the two weights should be attached on the same side. preferable. This is two weights 19
The same applies to the case where is attached above and below the frame 50.

Further, in the rotor 18 having the above structure,
Even if the weights 19 are not used, the center of rotation and the center of gravity can be shifted. For example, as shown in FIG. 9, a cylindrical frame 50, circular plate members 51, 51 covering both side openings of the frame 50, and a bearing (not shown) attached in a form penetrating the center of the plate members 51, 51. In the rotor 18 having the rotation shaft 16 rotatably supported, the plate member 51 is provided with the opening hole 51a so that the center of gravity is displaced from the center of rotation. The opening hole 5
1a is not limited to only one plate member 51a,
It is more effective to form both plate members 51, 51. In this case, if the holes 51a are formed on the same side, the amount of imbalance is large and a large amount of vibration can be obtained.

[0034]

According to the present invention, the eccentric rotor has the coils of a plurality of phases and the frame which holds the coils and whose center of rotation is at a position deviated from the center of gravity, and the frame is made of a conductive metal. Therefore, increase the weight, and
It is possible to increase the amount of weight imbalance, and it is possible to generate vibration with a low damping rate. Further, by increasing the weight of the frame, it becomes possible to obtain a vibration of a sufficient magnitude even at low speed rotation. Further, by having an arc-shaped brim portion on the outer peripheral edge of the frame, it is possible to increase the weight, so that a larger weight imbalance amount can be obtained and vibration with a low damping rate can be generated. Is possible. Further, it is possible to obtain a vibration of a sufficient magnitude even at low speed rotation.

Furthermore, since the second terminals of the coils of a plurality of phases are commonly connected to the coils and the coils are star-connected, the coils can be easily connected and the assembly cost can be reduced. Become. In addition, since the bearing is held by the cylindrical portion that is integrally provided in the frame, and this bearing is inserted into the shaft fixed in the casing and the eccentric rotor is rotatably supported, a common connection is made to the frame. Current can be passed from the plurality of second coil terminals to the shaft through the bearing, which contributes to reduction of electrical noise and the like.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a vibration motor according to the present invention.

FIG. 2 is a plan view showing an embodiment of a rotor applied to the same vibration motor.

FIG. 3 is a plan view showing an embodiment of a frame applied to the same vibration motor.

FIG. 4 is a sectional view showing an embodiment of a frame applied to the same vibration motor.

FIG. 5 is a plan view showing another embodiment of a rotor applied to the vibration motor according to the present invention.

FIG. 6 is a perspective view showing another embodiment of a coil applied to the vibration motor according to the present invention.

FIG. 7 is a perspective view showing still another embodiment of a rotor applied to the vibration motor according to the present invention.

8A and 8B show another embodiment of the rotor applied to the vibration motor according to the present invention, FIG.
Is a perspective view.

FIG. 9 is a perspective view showing still another embodiment of a rotor applied to the vibration motor according to the present invention.

FIG. 10 is a sectional view showing an example of a conventional vibration motor.

FIG. 11 is a plan view showing an example of a frame applied to the same vibration motor.

[Explanation of symbols]

 1 case 2 bottom plate 3 eccentric rotor 4 coil 5 frame

Claims (4)

[Claims] 1. A vibration motor comprising an eccentric rotor rotatably supported in a casing composed of a cup-shaped case and a bottom plate covering an opening of the case, and vibration generated by the rotation of the eccentric rotor. The eccentric rotor has coils of a plurality of phases and a frame that holds the coils and has a rotation center at a position deviated from the center of gravity, and the frame is made of a conductive metal. Vibration motor. 2. The eccentric rotor has a plate-shaped commutator, and the first terminals of the coils of the plurality of phases are connected to different segments of the commutator, respectively.
2. The vibration motor according to claim 1, wherein the second terminals of the coils of the plurality of phases are commonly connected to the frame, and the coils are star-connected. 3. A cylindrical portion integrally provided on the frame holds a bearing, the bearing is inserted into a shaft fixed in a casing, and an eccentric rotor is rotatably supported. The vibration motor according to claim 1 or 2. 4. The vibration motor according to claim 1, further comprising an arc-shaped collar portion on the outer peripheral edge of the frame.