JP2574978Y2 - Motor driven music box - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor-driven music box in which a rotary drum for resiliently driving a valve of a diaphragm is driven by a motor through a reduction gear train.

[0002]

2. Description of the Related Art Conventionally, there has been known a motor-driven music box in which a rotary drum for repelling a valve of a diaphragm is driven by a motor via a reduction gear train. The rotating drum, diaphragm,
The reduction gear train and the motor are supported by a frame that forms a substrate of the music box. Each gear constituting the reduction gear train is rotatably supported by the frame by cutting its shaft into a notch or bearing provided in the frame.

[0003] In a motor used as a drive source, a rotor on which windings are wound is supported by a shaft rotatably supported by a bearing provided on a frame. The rotor is provided with a commutator that is pressed against a brush connected to a power supply, and switches the direction and phase of a current supplied from the brush and flowing through the winding.

[0004]

[Problems to be Solved by the Invention] By the way, motor-driven music boxes that use a motor having a cylindrical commutator as a drive source have a reputation for noise and motor reliability. Because the taeter is cylindrical, it is necessary to spread the brush, which is narrower than the width (diameter) direction of the commutator, in some way to press against the commutator when assembling the motor. The assembly is more troublesome than the assembly of the reduction gear train, which only needs to be cut into the provided cuts and bearings, making it difficult to automatically assemble the motor-driven music box. On the other hand, there is a commutator formed in a disk shape in consideration of the bulk in the axial direction and the assembling property. However, since this commutator is mainly manufactured by etching or the like, the material and the thickness of the commutator are different. There is a problem that sufficient durability cannot be obtained as compared with a cylindrical commutator.

[0005]

Accordingly, the motor-driven music box of the present invention comprises a stator portion having a magnet disposed in a stator case and a rotor core having a magnetic center at a position shifted from the magnetic center of the magnet. A small brushed DC motor having a rotor portion formed by winding a coil, a commutator unit provided with a commutator formed substantially in a conical shape by rotating integrally with the rotor portion, and engaging with the small DC motor. A rotating drum provided with a plurality of pins corresponding to the number of tracks, a diaphragm provided with a plurality of valves resiliently vibrated by the plurality of pins, and the rotating drum , A diaphragm, a reduction gear train, and a frame that supports the small DC motor, and supports the rotor unit and the commutator unit. But to support the small DC motor in a direction orthogonal to the frame.

[0006]

The small DC motor is rotated in such a manner that the axis supporting the rotor and the commutator unit formed in a conical shape is orthogonal to the rotating drum, the diaphragm, the reduction gear train and the frame supporting the small DC motor. Because of the support, the motor is assembled to the frame by dropping the rotor and the commutator unit with respect to the shaft, similarly to the reduction gear train.

[0007]

1 and 2, reference numeral 1 denotes a motor-driven music box. The motor-driven music box 1 has a well-known rotary drum 3 whose shafts at both ends are rotatably supported on a frame 2A thereof, and a large number of valves 4a which are repelled by a plurality of pins 3a implanted on the peripheral surface of the rotary drum 3. , A driving motor 5 and a reduction gear train 6.

The diaphragm 4 is fixed to the frame 2A with screws 7. A drum gear 8 is fixed to one end of the rotating drum 3, and the gear 8 meshes with a final gear 9 of the reduction gear train 6. The reduction gear train 6 includes the gear 9 described above.
, A gear 10, a gear 11, a worm gear 12 integral with the gear 11, a worm 13, and a gear 14 integral with the worm 13
It is constituted by.

The gear 14 is a rotor 15 of the motor 5.
And is in mesh with a motor gear 30 formed of an insulating material. The gears 9, 10, 11, and 12 are supported by dropping both ends of their shafts into recesses 31, 32, and 33 (see FIG. 3) of the frame 2, respectively. As shown in FIG. 2, the worm 13 has one end supported by the frame 2A and the other end supported by the lid 2B.

The drive motor 5 is a flat type small DC motor, and is disposed at a corner of the frame 2A. The drive motor 5 includes a stator section 20 in which arc-shaped magnets 17 and 18 are disposed on a yoke 19 as a stator case, and a coil 16 on a rotor core 15A having a magnetic center at a position shifted from the magnetic center of the magnets 17 and 18. It mainly includes a wound rotor portion 15, a commutator unit 22 provided with a commutator 21 formed in a substantially conical shape that rotates integrally with the rotor portion 15, and a pair of brushes 23 in contact with the commutator 21. .

The yoke 19 has a magnet 1 on its inner peripheral surface.
7 and 18 are fixed, and are fixed and supported by being dropped into a concave portion 2 a surrounding substantially 3/4 around a yoke 19 formed on the frame 2. Brush 23
Is fixed to the lid 2B and connected to a power source (not shown).

A cylindrical bearing 25 protruding upward is formed on the bottom 2b of the frame 2. This bearing 25
, A support shaft 24 for supporting the rotor core 15A is press-fitted and supported so as to be orthogonal to the frame 2.

The rotor core 15A is formed by laminating silicon steel sheets having excellent magnetic properties. As shown in FIG. 4, anchor-shaped projections 15B extend in three directions. As shown in FIG. 5, a hole 15C is formed in the center of the rotor core 15A, and a boss 27a of a commutator holder 27 that supports the commutator 21 is fitted into the hole 15C. . The coil 16 is wound around the rotor core 15A via an insulator 26. The rotor core 15A has its magnetic center aligned with the magnets 17 and 1.
8, and is always biased in the direction of the arrow P.

A recess 27b is formed in the boss 27a of the commutator holder, and a shaft hole 28 for loosely supporting the tip 24a of the support shaft 24 formed in a conical shape is formed in the recess 27b. Is formed. The closed side of the shaft hole 28 has a vertex on the center line L of the support shaft 24 and is formed in a cone shape slightly larger than the apex angle of the tip 24a.
The contact resistance between the shaft hole 4a and the shaft hole 28 is reduced.

As shown in FIG. 5, a boss 30a of a gear 30 rotatably supported by a support shaft 24 is provided in the recess 27b.
Is press-fitted. Therefore, the gear 30, the commutator holder 27 and the rotor core 15A are integrated, and the support shaft 2
4 rotatably supported.

On the top surface of the commutator holder 27, there is formed a conical portion 27b which rises in a conical shape. Is provided by insert molding.

The commutator 21 switches the direction of the current flowing through the coil 16, and in the present embodiment, the groove 21a is cut by a cutter (not shown) to be divided into three pieces to form three pieces. A pair of brushes 23 is in contact with a part of 21a (see FIG. 4). A part of the outer periphery of the commutator 21 is radially extended from the commutator holder 27 and is integrally formed with three electrode terminals 29 in three directions.
Are in contact with the coil 16.

The brush 23 transmits a current from a power supply (not shown) to the commutator 21, and has a slope similar to that of the conical surface of the commutator 21 so that the lid 2B
When the cover 2B is attached to the frame 2A, the cover 2B comes into contact with the commutator 21 at a constant pressure.

On the other hand, the rotor core 15A and the magnet 1
7 and 18 are arranged coaxially with respect to the support shaft 24 with an air gap d provided therebetween. The air gap d is set so as to take into account thermal expansion due to high-speed rotation and long-time operation of the rotor unit 15 and to maintain a large magnetic flux density.

The assembling of the drive motor 5 in the motor drive music box 1 constructed as described above is performed by assembling the yoke 19 having the magnets 17 and 18 fixed to the inner peripheral surface of the frame 2.
Then, the support shaft 24 is dropped into the bearing portion 25 and press-fitted. Then, the previously integrated commutator holder 27, rotor portion 15 and gear 30
Is inserted into the support shaft 24 from above the frame 2A, and the cover 2B
The brush 23 is fixed to the frame 2A so as to contact the commutator 21. In the present embodiment, the bearing 25 is formed integrally with the frame 2A, but may be formed separately.

[0021]

According to the present invention, the motor for driving the rotary drum is supported on the frame with the axis supporting the rotor and the commutator unit orthogonal to the frame. Can be assembled by dropping the rotor shaft into a bearing provided on the frame, as in the assembly of the reduction gear train.
In addition, the commutator has a conical shape, so there is no need to extend the brush interval to contact the commutator, and the axial width is reduced compared to a cylindrical commutator, and a circular commutator is used. The range of choices such as material and plate thickness is wider than that of thetater. Therefore, the motor assembling work is improved while the flattening of the motor and the durability of the commutator are improved, and the problem of the automatic assembling work of the motor-driven music box is solved.

[Brief description of the drawings]

FIG. 1 is a plan view of a motor-driven music box showing one embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view showing a frame of the music box.

FIG. 4 is a perspective view of a commutator unit and a rotor unit, which are main parts of a motor.

FIG. 5 is an enlarged sectional view taken along line BB of FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 motor-driven music box 2A frame 3 rotating drum 3a plural pins 4 diaphragm 4a plural valves 5 small DC motor 6 reduction gear train 15 rotor part 15A rotor core 16 coil 17, 18 magnet 19 stator case (yoke) 20 stator part 21 Commutator 22 Commutator unit 23 Brush 24 Shaft (support shaft)

Claims (1)

(57) [Scope of request for utility model registration] A stator provided with a magnet disposed in a stator case; a rotor formed by winding a coil around a rotor core having a magnetic center at a position shifted from the magnetic center of the magnet; A small DC motor with a brush having a commutator unit provided with a commutator formed in a substantially conical shape that rotates together, and a rotary motor driven through a reduction gear train that engages with the small DC motor. A rotating drum provided with a plurality of pins, a diaphragm provided with a plurality of valves resiliently vibrated by the plurality of pins, and supporting the rotating drum, the diaphragm, a reduction gear train, and the small DC motor. A frame supporting the rotor portion and the commutator unit, and the axis supporting the rotor unit and the commutator unit is oriented in a direction orthogonal to the frame. A motor-driven music box that supports the motor on the same frame.