JPH031377A - Coil for magnetic head driving device - Google Patents

Abstract

PURPOSE:To eliminate the looseness of a screw between a coil and a head arm and to stably execute the positioning operation of a magnetic head by providing a bobbin, for which a notched part from an outside to a pickup hole is provided, between fitting holes. CONSTITUTION:A notched part 12 is provided in a central part in the inside of each fixed part 11 in a bobbin 6a and this notched part 12 reaches a pickup hole part 13a of the bobbin 6a. Then, the bobbin 6a is almost U-shaped and a coiling wire 6b is adhered to the upper and lower surfaces of this bobbin 6a. Since such a coil 6 can absorb the thermal shrinkage of the bobbin 6a by the notched part 12 even when the change of a temperature is repeatedly received, large stress is not received in the fixed part 11. Thus, the crack of the fixed part and the warp and twist of the bobbin to be caused by fastening the screw is eliminated, the stable positioning operation of the magnetic head can be always executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head drive device for a magnetic disk drive, and particularly to a coil for a magnetic head drive device using a voice coil motor.

[Conventional technology]

In a magnetic disk device, among the magnetic head drive devices for positioning the magnetic head on a predetermined cylinder of the magnetic disk, those using a voice coil motor as the drive source are magnetic heads attached to a holding member that holds the magnetic head. A coil that moves together with the coil, and a permanent magnet (magnet) that is fixedly installed in correspondence with this coil.
It is configured to provide motion for positioning the magnetic head by the attractive or repulsive force between the magnetic flux generated by passing a current through the coil and the magnetic flux generated by the permanent magnet. .

FIG. 3 is a diagram showing an example of a magnetic head drive device using a voice coil motor as a drive source as described above.
a) is a plan view, and FIG. 3(b) is a view taken in the direction of arrow A.

In FIG. 3, the coil 6 is connected to the helad arm 3 (rotating shaft 4
The magnet 8 is fixed to the coil 6 by a screw 10, and a magnet 8 is adhesively fixed to the upper surface and the lower surface of the coil 6, respectively. Therefore, by passing a current through the winding 6b, an attractive force or a repulsive force is generated between the coil 6b and the permanent magnet 8, which gives rotational motion to the coil 6 and positions the magnetic head 2 on a desired cylinder. movement is driven. This coil 6 is fixed to the head arm 3 with a screw 10. In Fig. 3, 1 is a magnetic disk, 2 is a magnetic head, 5 is an upper support plate, 7 is a yoke,
8 is a magnet, and 9 is a spacer.

FIG. 2 is a plan view showing details of a coil of a conventional magnetic head drive device, in which a winding 6b is wound around a bobbin 6a, and a punch hole 13b is provided.

[Problem to be solved by the invention]

The coil of the conventional magnetic head drive device configured as described above is frequently subjected to stress caused by the temperature difference between when the magnetic disk drive is in use and when it is not in use, and the coil is often subjected to stress caused by the tightening of the bobbin and head arm by screw fixing. The disadvantage is that the force deteriorates, resulting in loosening of screws, warping of the bobbin, cracking of screw fixing parts, etc., which may prevent smooth positioning of the magnetic head and cause unstable positioning. have.

An object of the present invention is to eliminate the drawbacks of the coil of the conventional magnetic head drive device as described above, so that even when subjected to repeated temperature changes, the screw between the coil and the helad arm does not loosen, the tightening does not occur, and the part cracks. It is an object of the present invention to provide a coil for a magnetic head drive device that is free from twisting, warping, etc. of the bobbin and allows stable positioning of the magnetic head.

[Means to solve the problem]

The coil of the magnetic head drive device of the present invention is provided with a winding portion and two mounting holes for supporting the winding portion and passing screws for mounting to the head arm, and a hole is punched from the outside between the mounting holes. The bobbin is provided with a notch that reaches up to the end of the bobbin.

〔Example〕

Next, examples of the present invention will be described.

FIG. 1 is a plan view showing details of a coil of a magnetic head driving device according to an embodiment of the present invention.

As shown in FIG. 1, a notch 12 is provided at the inner center of each fixing portion 11 of the bobbin 6a. This notch 12 reaches a hole 13a of the bobbin 6a, and the bobbin 6a has a substantially U-shape, and the winding 6a is bonded to the upper and lower surfaces of the bobbin 6a.

Even if the coil 6 configured as described above is subjected to repeated temperature changes, the notch portion 12 can absorb the thermal contraction of the bobbin 6a, so that the fixed portion 11 is not subjected to large stress as in the conventional case. There is no. Therefore, cracking of the fixed portion 11, warpage, twisting, etc. of the bobbin 6a due to tightening of the screw 10 is eliminated, and the positioning operation of the magnetic head can always be performed stably.

〔Effect of the invention〕

As described above in detail, the coil of the magnetic head drive device of the present invention has the effect of preventing the generation of large stress due to temperature changes in the screw fixing portion between the bobbin and the helad arm. This has the effect of preventing loosening of screws, cracking of the bobbin, twisting and warping of the screws in this portion, and ensuring stable positioning of the magnetic head at all times.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a coil of a magnetic head drive device according to an embodiment of the present invention, FIG. 2 is a plan view showing a coil of a conventional magnetic head drive device, and FIGS. 3(a) and (b) are FIG. 1 is a plan view and a view taken along arrow A, respectively, showing an example of a conventional magnetic head driving device. 1...Magnetic disk, 2...Magnetic head, 3...
Arm, 4... Rotating shaft, 5... Upper support plate, 6...
・Coil 6a...Bobbin, 6b...Winding, 7...
Yoke, 8...Magnet, 9...Spacer, 1o
...Screw, 11...Fixing part, 12...Notch, 1
3a, 13b... punch holes.

Claims (1)

[Claims] A bobbin including a winding part, two mounting holes for supporting the winding part and passing screws for mounting onto the head arm, and a notch reaching from the outside to the punching hole between the mounting holes. A coil for a magnetic head drive device, comprising: