JPS62110676A - Positioning carriage for magnetic disc device - Google Patents

Abstract

PURPOSE:To reduce a malfunction in a read/write operation and to improve reliability by providing a flat spring, the one end, at least, of which is mounted on either of an arm, a housing, or a motor, and a mass mounted on the flat spring. CONSTITUTION:When a coil 7 is moved rapidly by a read or a write instruction, a vibration in the coil 7 occurs by its vibrating force. By the vibration, a mutual position change between the information position of a magnetic head 1 and that of a magnetic disc 5, that is, an off-track is generated. However, by setting the spring constant of a flat spring 12 at a low level to some degree, a mass 13 is moved with some phase difference against the cycle of the vibration of the coil 7, and therefore, the vibration of the coil 7 is reduced. On the other hand, a resonance occurs in the flat spring 12 and the mass 13, but a resonance frequency of low grade is sufficiently low compared with a troublesome frequency in a servo loop, and the vibration level in the resonance frequency of high grade is low and is insignificant.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a positioning carriage used in a magnetic disk drive.

[Prior Art] In general, in a movable head type magnetic disk drive, as soon as there is a request to recall specific information on the magnetic disk, the movable head is moved rapidly in the radial direction of the magnetic disk so as to minimize the recall time. Must be positioned.

FIG. 3 shows a longitudinal cross-sectional view of a conventional carriage. For example, in the case of a rotary type magnetic disk drive, the magnetic head 1 is attached to an arm 2, the arm 2 is attached to a housing 3, and the carriage rotates around a rotating shaft 4. The magnetic head 1 is brought to an appropriate position on the magnetic disk 5, and as the magnetic disk 5 rotates about the shaft 6, magnetic data is written and read. A voice coil motor coil 7 (hereinafter referred to as a coil) is attached to the housing 3, and by passing current through the coil 7, a permanent magnet 8 is attached.
A force is generated between the magnetic head 1 and the coil 7, which causes the magnetic head 1 to
rotates. In addition, 9 is a magnetic circuit constituted by the coil 7 and the permanent magnet 8, 10a and 10b are bases, and 11 is a bearing. The positioning of the magnetic head 1 is generally performed using a servo circuit system that forms a closed loop of magnetic head 11 position detection pass point control circuit -> power coil 7 for point coil motor -> movement of coil 7 -> movement of magnetic head 1 -> detection of position of magnetic head 1 controlled by

[Problems to be solved] In the positioning carriage of a conventional magnetic disk device, when the magnetic disk drive 1 moves rapidly due to a command such as a call, mechanical resonance occurs in the servo loop as described above. If this resonance frequency is too low or the vibration level is too high, the servo system will resonate, making accurate positioning impossible.

[Means for Solving Problems] The present invention has been made by focusing on the problems of the conventional methods described in L. Conventionally, the recording density of magnetic disks was low and there was sufficient margin for reading and writing information. With the increase in storage density and capacity in recent years, there is no margin when reading and writing information, and it is necessary to increase the resonance frequency or lower the vibration level.
It is an object of the present invention to provide a positioning carriage for a magnetic disk device that can lower the vibration level of the resonance frequency, facilitate control of a servo system, and ensure reliable and stable positioning of a magnetic head.

To this end, the present invention provides a magnetic head, an arm that supports the magnetic head, a housing that supports the arm,
A positioning carriage for a magnetic disk device having a motor for driving the housing, at least one end of which includes a plate spring attached to either the arm, the housing, or the motor, and a mass attached to the plate spring. A positioning carriage for a magnetic disk device is provided.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIGS. 2(a) and 2(b) are a plan view and a longitudinal sectional view showing details of section A in FIG. 1.

In FIG. 1, 9 is a magnetic circuit consisting of a permanent magnet 8 and a coil 7. A housing 3 is operated by a magnetic circuit 9. An arm 2 is attached to the housing 3, and a magnetic helad 1 is attached to the arm 2. This arm 2 rotates around a rotating shaft 4 which is supported via bases 10a, 10b and bearings 11. 5 is a magnetic disk, 12 is a leaf spring installed in the coil 7,
Reference numeral 13 indicates the zero-order mass attached to the leaf spring, and its operation is shown. When the coil 7 moves rapidly in response to a read or write command, the coil 7 vibrates due to the excitation force. This vibration causes a mutual positional change between the information position of the magnetic head 1 and the magnetic disk 5, that is, off-track.

However, if the spring constant of the leaf spring 12 is set to be low to some extent, the mass 13 moves with a certain phase difference with respect to the period of vibration of the coil 7, so that the vibration of the coil 7 becomes small.

(Due to the mass damping effect of the servo loop 113) On the other hand, there is resonance that occurs between the leaf spring 12 and the mass 13, but its low-order resonance frequency is a frequency that becomes a problem in the servo loop (approximately 30
(0 to 3 KHz), and the high-order resonance frequency also has a low vibration level and does not pose a problem. In the above-described embodiment, the plate spring 12 is attached to the coil 7, but the same effect can be obtained even if the plate spring 12 is attached to the arm 2 or the housing 3. In addition, as another example, the shape of the leaf spring 12 is adjusted so that the resonance frequency of the arm 2, the housing 3, the coil 7, etc. generally matches.
By calculating the size of the mass 13 and considering the vibration modes of the arm 2, housing 3, and coil 7 and the mounting position of the leaf spring 12, it is possible to reduce the vibration of each member.

[Effects of the Invention] As explained above, the present invention provides a magnetic disk drive having a magnetic head, an arm for supporting the magnetic head, a housing for supporting the arm, and a motor for driving the housing. The positioning carriage for a magnetic disk device is characterized in that at least one end of the positioning carriage is provided with a leaf spring added to one of the arm, the housing, or the motor, and a mass attached to the leaf spring. This has the advantage that malfunctions are less likely to occur during write/read operations, and therefore reliability can be improved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a positioning carriage of a magnetic disk device according to an embodiment of the present invention, and FIGS. 2(a) and (b)
1 is a plan view and a vertical cross-sectional view showing details of section A in FIG. 1, and FIG. 3 is a vertical cross-sectional view of a positioning carriage of a conventional magnetic disk device. 1: Magnetic head 2: Arm 3: Housing 5: Magnetic disk 7: Pois coil motor coil 12: Leaf spring 13: Mass

Claims (1)

[Claims] In a positioning carriage for a magnetic disk device that includes a magnetic head, an arm that supports the magnetic head, a housing that supports the arm, and a motor that drives the housing, at least one end is connected to the arm, the housing, and the motor. 1. A positioning carriage for a magnetic disk device, comprising a leaf spring attached to one end of the carriage, and a mass attached to the leaf spring.