JPS60223459A - Voice coil motor - Google Patents

Abstract

PURPOSE:To accelerate the rotational motion speed of a voice coil motor, by using non-conductor plate resin for a movable coil bobbin and by strengthening the outer circumference with a non-magnetic metal or the like. CONSTITUTION:Non-conductive resin is used for a plate bobbin 14 for a movable coil 13 for a voice coil motor, and a coil 15 is fixed on the bobbin 14 with a channel containing the coil 15. And the outer circumference of the bobbin 14 except the coil 15 portion is inserted into a member 16 of L shape made of material (Al, ceramics or the like) more rigid than resin to be strengthened. And the upper portion of the member 16 of L shape is prevented from braking due to eddy current in case of magnetic flux reversal. As the result, the weak point on the rigidity of the resin bobbin 14 is strengthened with the member 16 and the rotational speed of the voice coil motor can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a voice coil motor that is used in a magnetic disk drive or the like and drives an actuator mechanism in which a magnetic head is mounted and a predetermined track is selected.

Prior Art and Problems In a magnetic disk device that performs recording and reproduction by magnetically floating a disk on a rotationally driven disk disk, an actuator mechanism that moves a magnetic head to a predetermined track to be recorded and reproduced is, for example, a first actuator mechanism. It is configured as shown in the figure.

FIG. 1 shows a sectional view of the actuator mechanism, and in the figure, a plurality of helad arms 2 holding magnetic heads 1 are stacked and locked to a rotating shaft 3. Both ends of the rotating shaft 3 are rotatably supported by a frame 4 via bearings 5, and the door arm 2 is rotated in the direction of arrow A by driving a movable coil 6 of a voice coil motor that is fixed to the rotating shaft 3. do. The voice coil motor has frame 4 and base plate 7.
It is formed by magnets 8A and 8B installed with a predetermined gap such that their magnetic poles NS face each other through the gap, and a movable coil 6 disposed within the gap.

FIG. 2(a) is a plan view of a moving coil of a conventional voice coil motor, and a sectional view taken along line AA in FIG. In the figure, a movable coil 6 is constructed by solidly layering a coil 10 on a bobbin 9 formed into a flat plate made of resin as an insulating material. The coil 10 is a wire rod with a rectangular cross section coated with an insulating coating, wound in a spiral shape, embedded and fixed in #111 provided on the bobbin 9, and provided with mounting holes on the rotating shaft 3 side so that the magnets 8A and 8B are located at the positions shown by the chain lines. It is attached by 12.

The movable coil 6 rotates by passing a predetermined current through the coil 10, but in order to increase the rotation speed and shorten the access time, it is necessary to close the gap S between the magnets 8A and 8B.
needs to be made as narrow as possible.

For this purpose, it is necessary to reduce the thickness t of the bobbin 9 of the moving coil 6. If the thickness t of the bobbin 9 is reduced, the wall thickness ta of the portion where the groove 11 is formed naturally becomes thinner, so the moving coil There is a problem that the strength of 6 is weakened and vibrations are more likely to occur.

(e) Purpose of the Invention An object of the present invention is to provide a voice coil motor equipped with a bobbin in which the bobbin strength does not decrease even when the thickness of the bobbin is reduced in order to narrow the gap between opposing magnets. According to the present invention, a winding wire is fixed on a flat bobbin to form a moving coil, and the winding wire of the moving coil is sandwiched between the winding wires and a predetermined gap. In a voice coil motor consisting of opposing magnets, the coil uses a flat bobbin made of non-conducting resin, a groove is provided in the non-conducting resin, the winding is fixed in the groove, and the coil is made of a flat bobbin. A voice coil motor characterized in that the outer periphery of the non-conducting resin is reinforced with non-magnetic metal or ceramics, or a flat bobbin is made of ceramics, and the windings are solidly layered on the ceramics. This is achieved by providing

(e) Examples of the invention DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below with reference to the drawings.

FIG. 3 is a plan view showing one embodiment of the moving coil of the voice coil motor of the present invention, and FIGS. 4 and 5 are pp of FIG. 3.
An lFr surface view is shown.

In the figure, the movable coil 13 uses a flat bobbin 14 made of nonconducting resin, and the coil 15 is fixed to the bobbin 14 by a groove into which the coil 15 is inserted. As shown in Fig. 2, a material (Az.

The L-shaped member 16 may be used to hold the material (ceramics, etc.), or as shown in FIG.
The outer periphery of the bobbin 14 except for the coil 15 portion is reinforced with a flat plate member 17 made of ceramics, etc.).

The reinforcement by the L-shaped member 16 in FIG.
) A plate or the like is used, the outer circumference of which is larger than the outer circumference of the coil 15, and cut to match the outer circumference of the bobbin (resin) 14.

The upper part of the L-shaped member 16 (see Fig. 3) is shaped as indicated by the solid line a to prevent it from acting as a brake when the magnetic flux is reversed due to a thin current.Also, the reinforcement by the flat plate member 17 in Fig. 5 is Flat aluminum (At) with a thickness of 0.1 to 1.0 m,
It can be easily manufactured by inserting ceramics etc. into a mold. At this time, in order to strengthen the reinforcement of the flat plate member 17, the upper part of the flat plate member 17 is
Twist as indicated by the dotted line b.

Further, the coil 15 is fixed on both sides of the resin of the bobbin 14 with an adhesive, and furthermore, the bobbin 14 has a rotating shaft 3.
Terminals (not shown) to which the starting and ending ends of the coil 15 are connected are provided.

When formed in this way, the rigidity of the resin bobbin is reduced by the above-mentioned Lff1 member 16. The flat plate member 17 increases the strength compared to the conventional resin button. Therefore, the bobbin 14 of the present invention
If the wall thickness ts□ of the coil groove is set so as to obtain the same strength as the wall thickness ts of the coil groove of the conventional resin bobbin 9, the wall thickness tas can be made thinner than the wall thickness ta. Therefore, the amount of thinning is the bobbin 14.
The thickness 11 of the voice coil motor can be made thinner, and the thinner thickness tl (see Figure 1) can narrow the above-mentioned gap S, resulting in an increase in the rotational speed of the voice coil motor. is measured.

FIG. 6 is a plan view showing a moving coil according to another embodiment of the present invention, and FIGS. 7, 8, and 9 are sectional views taken along the line pt-P in FIG. 6.

In the figure, a movable coil 18 is attached to a bobbin 19 with a coil 20
is fixed with adhesive or the like, and the rotating shaft 3 is attached to the bobbin 19.
There are a mounting hole 24 for locking the coil 20, and terminals (not shown) to which the starting and ending ends of the coil 20 are connected.

In the present invention, the bobbin 19 is made of a highly rigid ceramic plate, such as a 5isN4 series*ZrOtS 10□ series, which is strong against impact among ceramics, and is made to have a size slightly larger than the outer circumference of the coil 20. The coil 20 is then bonded to both sides of the bobbin 19 using an epoxy adhesive or the like as shown in FIG.

Furthermore, since the ceramic bobbin 19 usually has a very smooth and smooth surface, the adhesion strength with the coil 2o is weak. Irregularities 22 or stripes or ports are mechanically formed on the surface.

Furthermore, in order to increase the fixing strength, a bank 23 is created (using a jig) with adhesive or the like around the coil 20 setting position on the bobbin 19 as shown in FIG. To more reliably transmit the information to the bobbin side.

As described above, the bobbin 19 made of ceramic has a higher rigidity than the conventional resin bobbin 9. Therefore, if the total wall thickness t of the bobbin 19 and the coil 20 is the same as the wall thickness t of the conventional resin bobbin 9, the bobbin 19 of the present invention has a higher mechanical resonance point of the bobbin system than the resin bobbin 9.
High precision positioning becomes possible. Also, if the settings are made so that the same rigidity can be obtained, then the total thickness t of the bobbin 19 and coil 20 of the present invention is
, can be made as thin as 1-1. The above-mentioned gap S can be narrowed by the thinner part.

As a result, the rotational speed of the voice coil motor can be increased.

(f) Effects of the Invention As explained in detail above, the voice coil motor of the present invention uses a flat nonconducting resin for the bobbin of the moving coil,
Reinforce the outer periphery with non-magnetic metal or ceramics, or
Alternatively, by using a flat ceramic material, the rigidity of the entire bobbin becomes higher than that of a conventional resin bobbin. As a result, the thickness of the bobbin can be made as thin as possible, the gap between the magnets can be narrowed, and the voice coil motor can be rotated at a high speed.

[Brief explanation of the drawing]

Figure 1 is a sectional view explaining the actuator mechanism, Figure 2 (u) is a plan view of the moving coil of a conventional voice coil motor, Figure 2 (IP) is a sectional view taken along line A-A in Figure 2, and Figure 3 is a cross-sectional view of the conventional voice coil motor. FIGS. 4 and 5 are plan views showing one embodiment of the movable coil 8- of the voice coil motor of the invention.
-pWr plane view, FIG. 6 is a plan view showing a moving coil of another embodiment of the present invention, and FIGS. 7, 8, and 9 are PWr side views of FIG.
-P sectional views are shown respectively. In the figure, 13.18 is a movable coil, 14.degree. 20 is a coil, 16 is an L plate member, 17 is a flat plate member, 21.24 is a mounting hole, 22 is an uneven surface, and 23 is a bank.

Claims (1)

[Claims] (1) A voice coil consisting of a moving coil formed by solidly layering a winding on a flat bobbin, and magnets sandwiching the winding of the moving coil and facing each other with a predetermined gap. In the motor, the movable coil is made of a flat non-conducting resin, a groove is provided in the non-conducting resin, the winding is solidly layered in the groove, and the outer periphery of the non-conducting resin is made of non-magnetic metal or ceramics. A voice coil motor characterized by reinforcement. (In a voice coil motor, a moving coil is formed by solidifying a winding on a flat bobbin, and magnets sandwich the winding of a cough movable coil and face each other with a predetermined gap. A voice coil motor characterized in that a ceramic is used for a flat bobbin, and the winding is fixed on the ceramic. (3) A patent characterized in that the ceramic has a large number of grooves or irregularities on a plane. The voice coil motor according to claim 2. (4) The voice coil motor according to claim 2, wherein the ceramic has a resin member fixed to a plane other than the arrangement of the windings. 1.