JPH06217514A - Rotary vcm - Google Patents

Abstract

PURPOSE:To obtain a rotary VCM which has a small size, can be operated at a high speed, and does not cause any harmful vibration by constituting the coil of the VCM of a laminated coil. CONSTITUTION:The VCM 23 of a rotary VCM actuator 20 is provided with L-shaped yokes 24 and 24 and a prescribed magnetic circuit is constituted of nearly fan-shaped magnets 25 and 25 faced to each other with a magnetic gap in between in the space formed by the yokes 24 and 24. On the other hand, in a magnetic head device 28 driven by the VCM 23, a fan-shaped coil housing section is extended from one side of an arm spindle section 29 rotatably constituted around a rotating shaft 29a and the space of the section 26 in the thickness direction constitutes a magnetic gap G in which a laminated coil 27 is housed. Therefore, the space factor can be improved in the coil section of the VCM and the VCM can be reduced in size. At the same time, the occurrence of harmful vibrations can be prevented when the VCM is driven at a high speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary VCM (voice coil motor) for driving a magnetic head for reading and writing a magnetic disk, for example.

[0002]

2. Description of the Related Art Conventionally, in order to drive a magnetic head for recording or reproducing information on a magnetic disk in the radial direction of this magnetic disk, a rotary VCM as shown in FIGS. 6 and 7 is used. The VCM actuator 1 used is used. FIG. 6 is a schematic side view showing a conventional VCM actuator 1, and FIG. 7 is a plan view thereof.
In the figure, a VCM actuator 1 is composed of a rotary type VCM 3 provided on a base 2 and a magnetic head device 8 which is rotationally driven by the VCM 3.

The rotary VCM 3 has a substantially U-shaped yoke 4 provided on the base 2 and magnets 5 and 5 housed in the yoke with a predetermined gap 5a.
The coil 7 is arranged in the magnetic gap 5a of the magnetic circuit formed by the magnets 5 and 5. The magnetic head device 8 includes an arm spindle portion 9 configured to be rotatable, one end portion 6 extending from the arm spindle portion 9 to one side, and having the coil 7 attached to the tip side thereof, and an arm spindle portion. 9, an actuator body 10 formed of a gimbal spring or the like is provided, and a magnetic head slider 11 is attached near the tip thereof.

In the VCM actuator 1 as described above, when the coil 7 is energized, an electromagnetic force is generated and the arm spindle portion 9 rotates. As a result, the head slider 11 attached to the tip of the actuator (head arm) 10 is moved along the radial direction of the magnetic disk (not shown) as shown by the arrow in FIG.

[0005]

By the way, in such a rotary VCM, high speed and small size have been recently demanded. However, the coil 7 used in this rotary VCM 3 is formed of a winding coil, and such a winding coil is formed of a wire material having a wire diameter of about 1.5 [mm], for example. It is a thing. Therefore, although there is a degree of freedom in the winding pattern, the conductor section has a circular cross section, and the winding coil swells as it approaches the outer diameter. Therefore, the space factor is 30% to at most 60%. It is a degree.

Therefore, if the magnetic gap 5a provided for accommodating the coil 7 in the magnetic circuit is made small in order to make the rotary VCM 3 small, the electromagnetic force of the coil 7 becomes insufficient, so that the rotary VCM is generated. Since the torque to be applied is lower than in the past, it has been difficult to miniaturize the rotary VCM.

Further, even if the magnetic gap 5a has the same size as the conventional one, if the number of turns of the winding of the conventional winding coil 7 is increased, the coil 7 becomes large and cannot be accommodated in the magnetic gap 5a. It was difficult to speed up the VCM.

Further, as a problem peculiar to the conventional rotary type VCM using the wound coil, there are the following drawbacks.
That is, in the winding coil 7 used in the rotary VCM 3 shown in FIGS. 6 and 7, a wire rod having a circular cross section coated with polyurethane around the wire is wound for a predetermined number of turns, and It is configured by bonding using the self-bonding property.

Therefore, when the distance between the magnetic gaps 5a of the rotary VCM 3 is narrow, the number of turns in the thickness direction of the coil 7, that is, the direction of the gap distance is limited, so that the rigidity of the coil 7 is insufficient. . As a result, the rotary V
When the CM 3 is driven at high speed, there is a problem that harmful vibration called “squeaking” occurs due to insufficient mechanical strength of the coil 7.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a rotary VCM which is small in size, can operate at high speed, and does not cause harmful vibration.

[0011]

In the present invention, the above object is to arrange a coil in a magnetic gap of a magnetic circuit,
In a rotary VCM that obtains a rotary driving force by an electromagnetic force generated by passing a current through this coil, this is achieved by a rotary VCM in which the coil is a laminated coil.

Preferably, the coil is formed by stacking a plurality of laminated coils and connecting them.

The coil may drive the magnetic head via an actuator and move the magnetic head in the radial direction of the magnetic disk.

[0014]

According to the above construction, a laminated coil is used in which a rectangular wire having an extremely thin coating is wound around a coil forming a rotary VCM. For this reason, the conductor space factor is dramatically improved as compared with the conventional wound coil. Therefore, even if the magnetic gap accommodating this coil is equal to or smaller than the conventional one, the electromagnetic force generated in this coil is reduced. Grows.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The examples described below are preferred specific examples of the present invention, and therefore, various technically preferable limitations are attached, but the scope of the present invention is
Unless otherwise stated in the following description, the present invention is not limited to these embodiments.

FIG. 1 is an exploded perspective view of a rotary VCM actuator utilizing a preferred embodiment of the rotary VCM of the present invention. In the figure, the rotary VCM 23 of the rotary VCM actuator 20 is substantially L according to the present embodiment.
It is provided with yokes 24, 24 having a character shape. The yokes 24, 24 have a predetermined space (gap) from above and below each other.
Are opposed to each other.

In the space that defines the yokes 24 and 24,
Magnet 2 which is almost fan-shaped with a magnetic gap between them
5, 25 are arranged to face each other to form a predetermined magnetic circuit. Then, a laminate coil 27, which will be described later, is arranged in the magnetic gap G.

On the other hand, the magnetic head device 28 driven by the rotary VCM 23 has substantially the same construction as the conventional one. That is, a substantially fan-shaped coil accommodating portion 26 extends from one side of the arm spindle portion 29 configured to be rotatable about the rotation shaft 29a, and the space in the thickness direction of the coil accommodating portion 26 is the above-mentioned. It constitutes the magnetic gap G. A laminated coil 27 used in the rotary VCM 23 of this embodiment is accommodated in this gap G, and this state is shown in detail in the schematic sectional view of FIG.

An actuator 30, which is composed of a gimbal spring or the like and has a suspension function, extends to the other side of the arm spindle portion 29. The actuator 30 is formed in a taper shape, and a head slider 31 made of, for example, ferrite is provided near the tip of the actuator 30.

In the rotary VCM actuator 20 having the above structure, when the laminate coil 27 is energized, an electromagnetic force is generated and the magnets 24 and 2 are generated.
The coil 27 moves in the horizontal direction by the action of the magnetic circuit formed by 4 and the arm spindle unit 9 rotates. As a result, the actuator (head arm) 30
The head slider 31 attached to the front end of the magnetic disk D is moved in the direction opposite to the laminating coil 27, and thus the head slider 31 can be moved on the recording track along the radial direction of the magnetic disk D. It has become.

The structure of the laminated coil used in the rotary VCM 20 of this embodiment will be described below. 3A and 3B are views showing the structure of a rectangular wire for forming the laminated coil of the present embodiment. FIG. 3A is a longitudinal sectional view, and FIG. 3B is a sectional view taken in a direction orthogonal to the extending direction of the rectangular wire. It is a figure.

Unlike the known laminated coil, the laminated coil of this embodiment first rolls a round winding in the process of forming the rectangular wire 40, and then applies a predetermined insulating coating such as polyurethane, and then the winding. -Finish into a coil through peeling. That is, in FIG.
Reference numeral 41 is a conductor portion, which is made of, for example, copper.
An insulating layer 41 to be coated later is provided around the periphery of the insulating layer 41. The insulating layer 42 has a thickness of 2 μm, which is about half that of the insulating layer of the conventional laminate coil, and the space factor of the conductor can be improved by that much. Incidentally, 43 is an adhesive layer.

Such a rectangular wire 40 is used in this embodiment.
The wire width is about 0.5 [mm] and is wound as shown in FIG. In this example, the coil was wound 60 turns to obtain the coil shown in FIG. In the drawing of the coil 140, 141a is an inner terminal, 141b is an outer terminal, and an insulating layer 141c is provided around the coil 140.

In the rotary VCM 20 of this embodiment, as shown in FIG. 5, preferably two laminated coils 14 are used.
0 and 140 are overlapped to form a coil portion 27, which is housed in the coil housing portion 26. Here, the square coil 14
0 and 140 are stacked so that one is upside down with respect to the other, the terminals 141a exposed at the inner diameter are connected to each other, and the two terminals 141b at the outer diameter are used as lead wires. As a result, a coil with 120 turns can be obtained.

When the laminated coil thus constructed is compared with a conventional winding coil, for example, when the number of turns is matched for comparison with the above-described embodiment, 120 windings can be performed with the winding coil. , 12 in the radial direction of the coil
It is necessary to turn 10 turns in the thickness direction, and the thickness of the conventional coil is 1.7 [mm]. On the other hand, the laminated coil 14 used in this embodiment has a total coil thickness of 1.0 [mm] even if two layers are stacked, so that it is possible to reduce the size by 7 [mm] even if only the coil portion is focused. The rotary VCM can be miniaturized.

As described above, according to the rotary VCM of this embodiment, since the laminated coil is used, the conductor space factor of the coil portion can be improved, and the rotary VCM can be miniaturized. it can. Further, if the magnetic gap can be reduced, the magnetic flux density can be increased accordingly, which is effective in improving the performance of the motor. Further, for example, when the size of the rotary VCM is set to be the same as the conventional one, it is possible to obtain the rotary VCM that can be driven at extremely high speed.

Further, since the laminated coil is used for the coil portion, when the rotary VCM is driven at high speed,
It does not cause harmful vibration called "squeal" as in the past.

[0028]

As described above, according to the present invention, it is possible to reduce the size of a rotary VCM without degrading its performance. Further, it is possible to provide a rotary VCM that is the same size as or smaller than the conventional one, can operate at high speed, and does not cause harmful vibration.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a VCM actuator using a rotary VCM of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a main part of the rotary VCM shown in FIG.

FIG. 3 is a longitudinal sectional view (A) of a rectangular wire for producing a laminated coil used in the rotary VCM of FIG.
(B) Transverse sectional view.

4 is a perspective view showing a laminated coil used in the rotary VCM of FIG. 1. FIG.

5 is a perspective view showing a state where the laminated coil of FIG. 4 is housed in a coil housing part of a motor.

FIG. 6 is a side view showing an example of use of a conventional rotary VCM.

7 is a plan view of the rotary VCM of FIG.

[Explanation of symbols]

 20 rotary VCM actuator 23 rotary VCM 24 yoke 25 magnet 27 laminate coil 29 arm spindle section 30 actuator 31 head slider

Claims (3)

[Claims] 1. In a rotary VCM in which a coil is arranged in a magnetic gap of a magnetic circuit and a rotational driving force is obtained by an electromagnetic force generated by passing a current through the coil, the coil is composed of a laminated coil. A rotary VCM characterized by the following. 2. The rotary VCM according to claim 1, wherein the coil is formed by stacking a plurality of laminated coils and connecting them. 3. The coil is configured to drive a magnetic head through an actuator and move the magnetic head in a radial direction of a magnetic disk.
The rotary VCM according to claim 1.