JPH02143945A - Magnetic head device - Google Patents

Abstract

PURPOSE:To efficiently attenuate a resonance phenomenon caused by a torsional vibration without deteriorating the followup ability for a disk by providing a viscoelastic body at one position of the elastic part of a gimbal to be approximately symmetrical to the circumferential direction of the disk. CONSTITUTION:Viscoelastic bodies are embedded in two parts of the clearance parts between a substrate part 4a and an inner frame part 4b of the gimbal corresponding to the positions diagonal to the circumferential direction of a disk 6 with a head 3 as its center, and these viscoelastic bodies are fixed to the thin side faces of the substrate parts 4a and the inner frame parts 4b. In general, the maximum amplitude at resonance time tends to become smaller as viscous resistance becomes larger. Consequently, the viscous resistance of the torsional vibration can be heightened, and the resonance can be attenuated by embedding the viscoelastic body 1 at the diagonal positions. Thus, the resonance phenomenon caused by the torsional vibration can be efficiently suppressed without deteriorating the followup ability of the head for the disk.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a head or a head support structure used in a head device such as a floppy disk drive.

[Prior Art 1] A conventional head device has a structure shown in Japanese Patent Laid-Open No. 62-66481, which is shown in more detail in FIG. 6.

FIG. 6 is a diagram of a conventional gimbal structure. -09 The gimbal in a head device is used to support the head and bring the head and disk into smooth contact.
The gimbal is affixed to a carriage that moves it into position. Therefore, the gimbal is designed so that the magnetic head can easily follow the rotating disk and can move freely. However, periodic force generated by frictional force between the head and the disk is likely to be transmitted to the gimbal, and gimbal vibration caused by the force tends to cause a resonance phenomenon. Due to this resonance phenomenon, the spacing between the head and the disk changes in proportion to its resonance gain and at its resonance frequency, resulting in a decrease in the recording magnetic field and a decrease in the reproduction output (
(space loss) will occur periodically, making it impossible to ensure the performance of the disk device.

In order to suppress such a resonance phenomenon, a conventional gimbal structure was used as shown in the conventional example of Japanese Patent Application Laid-Open No. 62-66481 shown in FIG. In this gimbal structure, there are four gaps between the outer frame part 4a and the middle frame part 4b,
Viscoelastic bodies 28 to 2h, such as silicon adhesive, are installed at four locations in the gap between the middle frame portion 4b and the substrate portion 4c.

Generally, the maximum amplitude during resonance tends to decrease as the viscous resistance increases, so the resonance phenomenon caused by the frictional force between the head and the disk can be attenuated by the viscoelastic body.

[Problem to be Solved by the Invention 1] However, the conventional gimbal structure has the following problems.

First, as mentioned above, the gimbal that mounts the head is designed so that the head can move freely within a predetermined range, and the head and disk make smooth contact, reducing the space loss between the head and disk. You can hold it low and right. However, in the gimbal structure mentioned above, the viscoelastic body is installed in a total of 8 locations in the gap between the outer frame and the middle frame, and in the gap between the middle frame and the board, so the degree of freedom of movement of the gimbal is quite limited. This makes it difficult for the head mounted on the gimbal to follow the rotating disk, preventing smooth contact between the head and the disk, increasing space loss. Therefore, even if the resonance phenomenon is suppressed, the contact between the head and the disk deteriorates, causing problems such as a decrease in the recording field due to space loss and a decrease in the reproduction output.

Furthermore, since a viscoelastic body is installed at the same location, this increases manufacturing costs, and it cannot be said that the resonating vibration mode is suppressed efficiently. Here, the resonance mode will be explained below.

FIG. 7 is a distribution diagram of the forcing force caused by the friction between the head and the disk, and shows the approximate distribution of the forcing force f acting on a certain part of the head mounting portion 4d along the radial direction of the disk. , is an action diagram of forcing force during resonance. Both figures show only the vicinity of the cymbal substrate portion 4c.

The circular disk 6 is fixed by a disk fixing portion 6a at the center, and rotates with its outer circumferential portion open and in contact with the head. Therefore, as shown in FIG. 7, the force generated by the frictional force between the head and the disk is greater toward the center of the disk. However, the head and the rotating disk 6 often avoid stick-slip contact,
The distributed forcing shown in FIG. 7 is not always applied to the gimbal. What causes resonance and becomes a problem here is the circumference caused by stick slip! ! It is a type of coercive force. As mentioned above, since the forcing force is larger toward the center of the disk, the periodic forcing force f as shown in FIG. ■). Considering the case where the tie bar portions 7a act on a point, both tie bar portions 7a generate torsional vibration about the center axis of torsion passing through the head center 0 and the connection point between the middle frame portion and the tie bar portion. The gimbal is mainly caused by this torsional vibration.
1i% phenomenon occurs. Therefore, if only this torsional vibration is to be suppressed, there is no need to install a viscoelastic body at the same location.

As described above, the conventional example also has the problem of not effectively suppressing the resonance phenomenon.

Therefore, an object of the present invention is to suppress the resonance phenomenon caused by torsional vibration in the most efficient manner without deteriorating the tracking ability of the head with respect to the disk.

[Means for Solving the Problems] ■) The head device of the present invention includes: a head B that performs recording and reproduction by slidingly contacting at least one surface of an A3 rotating disk-shaped recording medium; a carriage for moving and positioning the head to a predetermined position by moving the head to a predetermined position; a gimbal for mounting the head on the carriage; the gimbal is provided with an elastic portion that configures a degree of freedom of movement that allows the head to follow the behavior of the disc-shaped recording medium; , the elastic section is characterized in that it includes viscoelastic bodies at positions that are substantially symmetrical in the circumferential direction of the rotating disc-shaped recording medium with the head as a basis.

The gimbal includes a substrate portion to which the head is fixed, an outer frame portion fixed to a part of the carriage, a middle frame portion formed between the plate portion and the outer frame portion, and a substrate portion and the middle frame portion. It is composed of a first tie bar that connects, and a second quiver that connects the middle frame part and the outer frame part, and the Aii recording elastic body is a space formed by the base part and the middle frame part or the middle frame part and the outer frame part. It is characterized by being buried or erected.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a cymbal drawing diagram showing one embodiment of the present invention, and FIG. 2 is a cymbal drawing diagram showing how the gimbal drawing shown in FIG. 1 suppresses the resonance phenomenon caused by torsional vibration. It is a gimbal structure diagram.

FIG. 3 is a gimbal structure diagram showing another embodiment. Fourth
The figure shows a general head support structure diagram of a head device, and FIG. 5 shows a general gimbal structure diagram.

First, the basic head support FMiW and cymbal structure will be explained based on FIGS. 4 and 5.

A gimbal in a head device is used to support the head and bring the head and disk into smooth contact, and the gimbal is fixed to a carriage that moves it to a predetermined position. Therefore, the gimbal is designed so that the magnetic head can easily follow the rotating disk and can move freely. Here, as shown in the head support structure diagram shown in FIG. The second head 14 is mounted via a first carriage 9 that is moved to a certain position and a second gimbal 12 that holds the second head 14, and the second head 14 is moved to a predetermined position together with the first carriage 9. The structure is such that the disk 6, which rotates once, is sandwiched between the second carriage 10 and the two heads brought into contact with each other under a predetermined load. Furthermore, the gimbal 4 shown in FIG. 5 has a thickness of 5
It is made by etching a flat metal plate such as stainless steel with a size of about 100 ft. The gimbal 4 includes, for example, an outer frame portion 4a fixed to a carriage, and an inner portion (Il) of the outer frame portion 4a.
1n11] and further 1n11 therein
The outer frame portion 4a and the substrate portion 4C and the middle frame portion 4b and the outer frame portion 4a each have a narrow first tie bar 78 having elasticity. and are connected at two locations each by a second tie bar 7b,
Each tie bar is provided at a position orthogonal to each other. Therefore, the head fixed to the substrate part 4C is the fifth head.
The head can freely move five times within a predetermined range around the two axes shown in the figure, and the head smoothly contacts the rotating disk.

The above is an outline of the basic head support structure.

Now, in this embodiment, as shown in FIG. 1, in two places in the gap between the base part 4a and the middle frame part 4b of the gimbal, which are located at a position opposite to fl+ in the circumferential direction of the disk 6 with the head 3 as the center. A viscoelastic material is embedded. The viscoelastic body is fixed to the thin side surfaces of the substrate portion 4a and the middle frame portion 4b.

The following describes how the above gimbal structure suppresses the resonance phenomenon caused by torsional vibration.6 First, as explained in the conventional example, the periodic forcing force generated by the frictional force between the head and the rotating disk is causes a resonance phenomenon. This vibration is complex, and in addition to the rotational vibration centered on the rotation axis on the quiver in the radial direction and the same direction as shown in FIG. The torsional vibration caused by the vibration is the main factor and causes a resonance phenomenon, and the spacing between the head 3 and the disk changes in magnitude proportional to the resonance gain and at the resonance frequency. A decrease in the recording field and a decrease in the reproduction output (space loss) occur periodically, making it impossible to ensure the performance of the disk. Now, in -F1a, the maximum amplitude at the time of resonance tends to decrease as the viscous resistance increases. Therefore, the viscoelastic body I
By embedding them at diagonal positions as shown in FIG. 1, the viscous resistance to torsional vibration increases and resonance can be damped. Note that the viscous resistance of this vibration system can be set by the viscosity coefficient and shape of the viscoelastic body 1.

By suppressing the resonance phenomenon as described above, the above-described reduction in the recording 6t1 field and the reduction in reproduction output (space loss) do not occur periodically, and the performance of the head device can be ensured.

In addition, as mentioned above, the gimbal is designed so that the mounted head can move freely, but the viscoelastic body is buried in only two places, so it does not greatly restrict the freedom of movement of the gimbal. The mounted head never becomes difficult to follow the rotating disk. Therefore, the performance of the head device can be ensured without increasing space loss. Furthermore, since the viscoelastic body is not installed at the same location, there is no significant increase in manufacturing costs.

In addition, in the gimbal structure diagram shown in FIG. 3 as another example, similar to the example shown in FIG. A tape-shaped viscoelastic body 2 is installed. The viscoelastic body is fixed on the substrate portion 4a and the middle frame portion 4b.

In this case as well, the resonance can be damped by increasing the viscous resistance to torsional vibration, as in the above-described embodiment. Therefore, the recording & H field decreases and the playback output decreases (
Space loss) does not occur periodically, and the performance of the head device can be ensured. In addition, the viscoelastic bodies installed are only at two locations, as in the previous example, so they do not greatly restrict the degree of freedom of movement of the gimbal (and do not make it difficult for the mounted head to follow the rotating disk). , without increasing space loss.Furthermore,
Since the viscoelastic body is not installed at the same location, there is no significant increase in manufacturing costs.

[Effect of the Invention 1] As described above, according to the present invention, the elastic part of the gimbal is provided with a viscoelastic body at a position substantially symmetrical to the circumferential direction of the disk, thereby improving the followability of the mounted head to the disk. It most efficiently attenuates the resonance phenomenon caused by the torsional vibration of the gimbal without causing any negative effects, and suppresses the loss of recording power and the decrease in playback output (space loss) caused by the resonance phenomenon, improving the performance of the head device. It has the 2JI effect of being able to ensure (disappointment).Furthermore, it is also possible to improve the yield in manufacturing disk devices.

[Brief explanation of the drawing]

Fig. 1 is a gimbal structure diagram showing one implementation of the present invention (511), and Fig. 2 is a gimbal structure diagram for explaining how the gimbal structure shown in Fig. 1 suppresses the resonance phenomenon caused by torsional vibration. Fig. 3 is a gimbal structural diagram showing another embodiment. Fig. 4 is a 6Q head support structure diagram of the head device. Fig. 5 is a 199 gimbal structural diagram. Fig. 6 is a conventional gimbal structural diagram. The gimbal structure diagram, Figure 7, is a distribution diagram of the forcing force caused by the friction between the head and the disk. Figure 8 is the action diagram of the forcing force during resonance. ■, 2... Viscoelastic body 3... ... Head 4 ... Gimbal 4a ... Board part 4b ... Middle frame part 4c ... Outer frame part 4d ... Head mounting part 5 ... Carriage 6 ...Disc 7a...First tie bar 7b...Second tie bar 9...First carriage 10...Second carriage 11... First gimbal 12...Second gimbal 13...First head 14...Second head a, b...Center axis of twisting Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1) A. A head that performs recording and reproduction by slidingly contacting at least one surface of a rotating disc-shaped recording medium; B. A head that moves in the radial direction of the disc-shaped recording medium and moves the head to a predetermined position. A carriage for moving and positioning the head, C, is composed of a plate-like member, fixes the head substantially in the center, fixes at least a part of the substantially outer periphery to a part of the carriage, and fixes the head to the carriage. a gimbal to be mounted, and the gimbal is provided with an elastic part that constitutes a degree of freedom of movement that allows the head to follow the behavior of the disk-shaped recording medium, and the elastic part is provided with an elastic part that allows the head to follow the behavior of the disk-shaped recording medium. 1. A magnetic head device comprising: a viscoelastic body provided at substantially symmetrical positions in the circumferential direction of the rotating disk-shaped recording medium with reference to . 2) The gimbal includes a substrate portion to which the head is fixed, an outer frame portion fixed to a part of the carriage, an intermediate frame portion formed between the substrate portion and the outer frame portion, and a connecting portion between the substrate portion and the intermediate frame portion. First thing to do
and a second tie bar connecting the middle frame and the outer frame, and the viscoelastic body is buried or built in the space formed by the base plate and the middle frame or the middle frame and the outer frame. A magnetic head device according to claim 1, characterized in that: