JPH0520825A - Negative-pressure type magnetic-head support device and magnetic disk apparatus - Google Patents

Abstract

PURPOSE:To provide a magnetic-head support device wherein a disk does not come into contact with a slider when the disk is turned and stopped and executes a recording or replay operation in the magnetic-head support device used for a magnetic disk apparatus. CONSTITUTION:In a loading and unloading type magnetic-head support device which is constituted of a negative-pressure type magnetic head 3, a gimbals 2 supporting it and a suspension 1, a constraint vibration-damping material 8 is pasted on the gimbals 2 supporting the negative-pressure type magnetic head 3. The negative-pressure type magnetic head and a magnetic disk can be loaded and unloaded in a noncontact manner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negative pressure type magnetic head supporting device and a magnetic disk device.

[0002]

2. Description of the Related Art FIGS. 8A and 8B are a plan view and a side view showing a conventional negative pressure type magnetic head supporting device, respectively. In FIGS. 8A and 8B, reference numeral 1 denotes a suspension composed of a leaf spring or the like, and the suspension 1 is bent near its root. 2 is suspension 1
The gimbal 3 attached to the gimbal 3 is a negative pressure type magnetic head attached to the gimbal. Below, negative pressure type magnetic head 3
Will be described with reference to FIG. In FIG. 9, reference numeral 3a denotes a slider body made of a magnetic material such as ferrite. The slider body 3a is provided with a U-shaped levitation rail 3b for generating a positive pressure, and the levitation rail 3b has a stepped portion 3c. It is provided. Further, 3d is a recess surrounded by the levitation rail 3b, and negative pressure is generated in the recess 3d. 3e,
Reference numeral 3f is a core joined to the slider body 3a via non-magnetic materials 3g and 3h, which are magnetic gaps. Three
i is a conducting wire wound around the core 3e. In this case, only the core 3e performs magnetic recording / reproduction. Air is lead 3i
Flows from the side opposite to the winding side (inflow end A) to the side on which the conducting wire 3i is wound (outflow end B). The suspension 1, the gimbal 2, and the negative pressure type magnetic head 3 constitute a support device 4.

FIG. 10 shows a state in which the supporting device 4 of the negative pressure type magnetic head thus constructed is mounted on the magnetic disk device.
Shown in. In FIG. 10, 5 is a magnetic disk, 6 is an arm to which the supporting device 4 is attached, and the arm 6 moves substantially parallel to the magnetic disk about a rotation axis (not shown). Reference numeral 7 is a load pin that presses the suspension 1 toward the magnetic disk 5, and the load pin 7 is driven by an actuator (not shown).

A method of loading a negative pressure type magnetic head of a magnetic disk device will be described below with reference to FIGS. 11 (A), (B), (C) and (D).
Will be explained.

Initially, as shown in FIG. 11A, the negative pressure type magnetic head 3 is held at a position away from the magnetic disk 5. Next, when the load pin 7 is driven by the actuator, the load pin 7 presses the suspension 1 toward the magnetic disk 5 side to bring the negative pressure type magnetic head 3 closer to the magnetic disk 5. This state is shown in FIG. When the load pin 7 further presses the suspension 1 toward the magnetic disk 5 and brings the negative pressure type magnetic head 3 close to the magnetic disk 5 to a predetermined position, a negative pressure acts on the negative pressure type magnetic head 3 and the negative pressure type magnetic head 3 becomes a magnetic disk. 5
It will be sucked up by and will float on the magnetic disk 5. This state is shown in FIG. When the negative pressure type magnetic head 3 floats, the load pin 7 stops pressing the suspension 1 and returns to a predetermined position. This state is shown in FIG.
It shows in (D).

When the negative pressure type magnetic head is to be unloaded, the negative pressure acting on the negative pressure type magnetic head 3 is reduced by reducing the rotation of the magnetic disk 5 to reduce the negative pressure type magnetic head 3.
Is separated from the magnetic disk 5 by the composite force of the suspension 1.

[0007]

However, in the above-mentioned conventional configuration, after repeated loading and unloading,
When the magnetic disk 5 is observed, many contact marks between the slider and the disk remain. This contact mark increases as the number of times of loading and unloading increases, and may occur over the entire circumference of the disk. The size is 80
It is about 100 μm. On the other hand, the slider on the disk where the contact marks are generated is likely to wear due to contact,
Occasionally, there is a problem that the head gap portion is worn and the head output is lowered.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a negative pressure type magnetic head supporting device and a magnetic disk device in which the negative pressure type magnetic head does not come into contact during loading / unloading. Is trying

[0009]

In order to achieve this object, the gimbal is provided with a restraining damping material.

[0010]

[Function] With this configuration, the load of the negative pressure type magnetic head
Vibration of the negative pressure type magnetic head that occurs during unloading can be suppressed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A negative pressure type magnetic head supporting device according to an embodiment of the present invention will be described below.

FIGS. 1A, 1B, and 1C are an enlarged view, a plan view, and a side view of a main part of a negative pressure type magnetic head supporting device according to an embodiment of the present invention, respectively. Figure 1
In (A), (B), and (C), 1 is a suspension,
Reference numeral 2 is a gimbal, and 3 is a negative pressure type magnetic head, which have the same construction as the conventional one. Reference numeral 8 denotes a constrained vibration damping material attached to the surface of the gimbal 2 opposite to the surface on which the negative pressure type magnetic head is mounted. The constrained vibration damping material 8 is configured as shown in FIG. In FIG. 2, reference numeral 9 is a damping material made of a viscoelastic material, and the damping material 9 has an effect of diffusing vibration energy by converting it into heat energy and dissipating it. A constraining plate 10 is provided on the damping material 9 and is made of a material such as polyimide. The damping material 9 and the restraint plate 10
The constrained damping material 8 is constituted by, and specifically, the damping material 9 is a double-sided tape or the like.

The negative pressure type magnetic head support of this embodiment was specifically mounted on a magnetic disk device as shown in FIG. 10 and various characteristics were measured in comparison with a conventional example.

(Experiment 1) Experiment of the effect of preventing contact during unloading The experimental apparatus has a spindle motor and a suspension mounting arm, and the suspension mounting arm is on a stage where the postures of the slider in the pitching and rolling directions can be freely changed. It is fixed to. Further, a vibration sensor is attached to the suspension mounting arm so that contact between the head disks can be detected.

The experiment is conducted as follows. The magnetic disk suspension was assembled into the experimental device, and the spindle was 3600.
After the steady rotation at rpm, the slider is loaded on the magnetic disk. After that, when the spindle is switched off, the rotational speed of the magnetic disk gradually decreases, the negative pressure generated in the negative pressure slider also decreases accordingly, and when the restoring force of the suspension becomes greater than the negative pressure, The slider unloads from the disc. At this time, the contact state between the disk and the slider is measured by a vibration sensor attached to the arm. The posture of the slider is considered as a parameter, and the posture is divided into the pitching direction and the rolling direction. That is, the difference in height from the disk at the inflow end and the outflow end of the slider at the moment of loading is the pitching posture, and the difference in height from the disc at the inner and outer circumference ends is the rolling posture. It was changed by moving the stage to which the suspension arm was attached, and the contact distribution during unloading was measured separately for the example and the conventional example.

(Results) FIG. 3 shows the experimental results. Figure 3
The measurement result of the conventional example is shown in (A), and the measurement result of the embodiment is shown in FIG. 3 (B). The horizontal axis of the graph represents the pitching posture, and the vertical axis of the graph represents the rolling posture. "" Indicates non-contact, and "x" indicates contact area. As can be seen from FIG. 3A, in the conventional example in which the restraint damping material is not provided on the gimbal, the slider and the disk come into contact with each other only when the slider slightly tilts from the disk. Further, as can be seen from FIG. 3 (B), it can be seen that in the example in which the restraint damping material is provided on the gimbal, it is possible to unload without contact within the measured range.

(Experiment 2) Experiment of the effect of preventing contact with external disturbance A continuous disturbance is given by applying external disturbance. After the test, the slider is observed under a microscope to confirm contact with the disk. The purpose of this experiment is to: In the load / unload mechanism type magnetic head supporting device, the negative pressure slider is thin and is supported by a gimbal having a small torsional rigidity. Initially, the slider is unlikely to be mounted parallel to the disc and has some tilt relative to the disc. However, since a thin air film is formed on the rotating disk (Fig. 4 (A)),
As the slider approached the disc, it gradually recovered its posture to be parallel to the disc (Fig. 4).
(B)), it can be loaded on the disk without contact (FIG. 4C). However, there is a limit in approaching the disk without contact and starting to levitate. This is when the frequency of the disturbance transmitted to the magnetic head supporting device is higher than the frequency at which the slider recovers its posture. At this time, the slider approaches the disk without being able to recover the posture, so the slider comes into contact with the disk. This contact is also a disk
Scratches are left on the slider, and the head gap is damaged, which adversely affects recording and reproduction.

The experimental apparatus has a spindle motor and a suspension mounting arm, which are fixed on an exciter capable of continuously applying vibration under a constant condition. The condition for vibration is that the acceleration frequency of 1 G (m / s ² ) in the vertical direction is 400H.
z.

In the experiment, loading and unloading are performed tens of thousands times under the above-mentioned vibration conditions. At this time, the spindle motor speed is 360
It is 0 rpm. Then, the slider after the experiment is observed with a microscope to confirm the contact with the disk 5.

(Results) FIG. 5A is a microscopic image of the negative pressure type magnetic head held by the supporting device of the conventional example, and FIG.
FIG. 3B shows a microscopic image of the negative pressure type magnetic head held by the supporting device of the embodiment. As can be seen from FIG. 5 (A), the slider portion of the negative pressure type magnetic head mounted on the conventional supporting device was worn by the contact of the disk (slider right end portion), but was mounted on the supporting device of the embodiment. It is not found in the slider part of the negative pressure type magnetic head. That is, since the restraint damping material is attached on the gimbal, the slider does not vibrate against external disturbance, so that the slider can be loaded / unloaded without contact.

(Experiment 3) A continuous load / unload test is repeated with and without the restraint damping material attached, and the change in head output before and after the test is observed.

(Results) The results are shown in FIG. The horizontal axis of the graph shows the number of times of loading / unloading, and the vertical axis shows the relative value of the head output. As shown in the figure, load
Head output is about 25% when the number of unloads is 100,000 or less
Although it decreases, in the embodiment, the output does not change even if the load / unload count is repeated 300,000 times or more.

As described above, in this embodiment, the disk and slider can be loaded and unloaded without contact. This is due to the following. A contact mark can be generated only by a negative pressure slider flying test. No contact mark is generated. Therefore, when the slider starts to fly on the disk (when loading) or when the slider stops flying from the disk ( It is one of the two. As to whether the contact mark was generated during loading or unloading, it was found that it was occurring during unloading as a result of testing the loading and unloading on separate tracks. However, in all the load and unload tests, contact marks did not occur, and in some cases it was completely intact, and the differences were considered. The movement of the slider immediately after unloading draws a free vibration waveform of the spring as shown in FIG. Now consider the attitude of the slider. The attitude of 0 means that the slider is parallel to the disk when the slider approaches the disk. When the posture is 0, the force exerted on the flying slider by the magnetic head supporting device is only the upward force of the suspension. Therefore, after the slider is unloaded from the disk, the slider moves according to the free vibration of the suspension. However, when the posture is not 0, that is, when the slider being loaded has a tilt with respect to the disk, the amount of tilt is absorbed as a gimbal twist after flying. Therefore, the floating slider has a force applied from the magnetic head supporting device to an upward force of the suspension and a force to recover the twist of the gimbal. Therefore, after the slider is unloaded from the disk, the slider becomes a vibration in which the free vibration of the suspension and the torsional vibration of the gimbal overlap. That is, it can be seen that the vibration amplitude of the slider is largely related to the posture, and the larger the posture, the larger the vibration amplitude. This increase in vibration amplitude affects the contact between the slider and the disk after unloading, and this contact leaves a contact mark on the disk, wears the slider, and damages the head gap, which causes recording and reproduction. Also has an adverse effect. Therefore, the present invention suppresses the increase in the vibration amplitude by attaching a restraining vibration damping material to the gimbal.

In this embodiment, the restraint damping material has a square shape, but may have another shape such as a circular shape. Further, although the restraint damping material is provided on the side opposite to the surface of the gimbal on which the negative pressure type magnetic head is attached, the same effect can be obtained by providing it on the surface on which the negative pressure type magnetic head is attached.

[0025]

By providing the restraint damping material on the gimbal, it is possible to suppress the vibration of the negative pressure type magnetic head that occurs during loading / unloading of the negative pressure type magnetic head.
The negative pressure slider and magnetic disk can be loaded and unloaded without contact.

[Brief description of drawings]

FIG. 1A is an enlarged view of a main part of a negative pressure type magnetic head supporting device according to an embodiment of the present invention. FIG. 1B is a plan view of a negative pressure type magnetic head supporting device according to an embodiment of the present invention. 1 is a side view of a negative pressure type magnetic head supporting device according to an embodiment of the invention.

FIG. 2 is an enlarged sectional view of an essential part of a negative pressure type magnetic head supporting device according to an embodiment of the present invention.

FIG. 3A is a diagram showing a result of a contact state between a negative pressure type magnetic head and a magnetic disk according to a rolling direction and a pitching posture by a conventional supporting device; The figure which shows the result of the contact state of a pressure type magnetic head and a magnetic disk.

4A is a side view showing a loading state of the negative pressure type magnetic head, FIG. 4B is a side view showing a loading state of the negative pressure type magnetic head, and FIG. 4C is a side view showing a loading state of the negative pressure type magnetic head.

FIG. 5A is a microscope image of a negative pressure type magnetic head held by a conventional supporting device. FIG. 5B is a microscope image of a negative pressure type magnetic head held by a supporting device of the present embodiment.

FIG. 6 is a diagram showing a relationship between the number of times of load / unload and a relative value of head output.

FIG. 7 is a diagram showing a vibration state of a negative pressure type magnetic head during unloading.

FIG. 8A is a plan view showing a supporting device for a conventional negative pressure type magnetic head device, and FIG. 8B is a side view showing a supporting device for a conventional negative pressure type magnetic head device.

FIG. 9 is a perspective view showing a negative pressure type magnetic head.

FIG. 10 is a perspective view of a negative pressure type magnetic head supporting device mounted on a magnetic disk.

11A is a side view showing a loading state of a negative pressure type magnetic head supporting device, FIG. 11B is a side view showing a loading state of a negative pressure type magnetic head supporting device, and FIG. 11C is a side view showing a negative pressure type magnetic head supporting device. Side view showing a state (D) Side view showing a loading state of a support device for a negative pressure type magnetic head

[Explanation of symbols]

1 suspension 2 gimbal 3 Negative pressure type magnetic head 8 Restraint damping material 9 damping material 10 Restraint plate

Claims (2)

[Claims] 1. A negative pressure type magnetic head supporting device comprising: a suspension; a gimbal provided on the suspension; and a negative pressure type magnetic head attached to the gimbal, wherein a restraining vibration damper is provided on the gimbal. . 2. A magnetic disk, an arm that moves substantially parallel to the magnetic disk, and a suspension provided on the arm so as to be separated from the magnetic disk.
A gimbal provided on the suspension, a negative pressure type magnetic head provided on one surface of the gimbal, and a suspension pressing means for pressing the suspension toward the magnetic disk to bring the negative pressure type magnetic head close to the magnetic disk. A magnetic disk device comprising: a gimbal, and a restraining vibration damping material provided on the gimbal.