JPH02312076A - Method for measuring force and friction coefficient generated between disk and head - Google Patents

Abstract

PURPOSE:To accurately measure the frictional force and force which are generated by providing plural sensors, measuring surface pressure and the frictional force while friction is generated between the disk and head, and measuring a side force while there is not the friction. CONSTITUTION:When the disk 7 is rotated while the friction is generated be tween the disk 7 and head 9, the surface pressure is measured by a floating force sensor 9. The current frictional force is measured by a frictional force sensor 9 and the side force generated while the disk 7 is rotated is measured by a side force sensor 9S. Then when the disk 7 is rotated while the friction is not generated between the disk 7 and head 9, its floating force is measured by the floating force sensor 9S. Consequently, the frictional force, floating force, and surface resistance force generated between the disk 7 and head 9 are accu rately measured and the measurement accuracy of the friction coefficient and generated forces can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a storage device using a disc-shaped recording medium,
This invention relates to a method for measuring the force and friction coefficient generated between a disk and a head.

[Prior Art] Conventionally, the friction coefficient has been measured by the method of ANS, I (American standard).

FIG. 3(a) is a plan view of a device showing a conventional measurement method.
Figure (b) is a sectional view taken along line B-H in figure (a). As is clear from FIG. 3, the conventional method for measuring the coefficient of friction, etc. is to remove the floating head slider 11, place a weight 12 on it, tie a thread 13 to the floating head slider 11 or the weight 12, and rotate the disk 16. This method uses a strain gauge 14 to measure the tension applied to the thread 13 when the tension is applied.

Note that 15 is a metal plate that restricts the movement of the floating head slider 11 in the radial direction from the center of the rotating disk 16;
It has a hole 17 at its tip, into which the weight 12 is loosely fitted.

[Problem to be Solved by the Invention] According to the conventional method described above, although it is possible to accurately measure the very initial coefficient of friction, it is not possible to accurately measure the coefficient of friction thereafter. , because when the disk 16 starts rotating, the floating head slider 11
is shifted in the radial direction of the disk 16, so the position to be measured for the friction coefficient is slightly shifted, making it impossible to accurately determine changes in the friction coefficient at the same location or the continuation of the lubricant's effect. , it is not possible to perform measurements under detailed condition settings.In other words, in the conventional method, the disk 16 is measured using a pseudo weight 12 having a constant weight.
By creating a state in which the RAD slider 11 and the floating RAD slider 11 are in contact with each other, in order to set the force in the surface pressure direction, which is the basis for calculating the friction coefficient, using the weight 12, the conditions are changed every 0.1 g, for example. However, it is very difficult to understand the changes in the coefficient of friction, and it requires a lot of effort and time.

The present invention has been made in order to solve such conventional problems, and it is an object of the present invention to provide a method for easily and accurately measuring the force and coefficient of friction generated between a disk and a head.

[Means for Solving the Problems] In order to achieve the above object, the method of the present invention provides a head or a head holder that holds this head with a levitation force sensor that measures the levitation force in the disk surface pressure direction, and a levitation force sensor that measures the levitation force in the disk surface pressure direction. A friction force sensor that measures the frictional force generated between the head holder and the disk and a side force sensor that measures the side force generated in the radial direction from the center of the disk are provided. By providing a means for measuring the distance between the head or the head holder and the disk, when friction with the disk occurs, it is possible to accurately measure the friction coefficient and change in the friction coefficient, and to check the friction between the head or the head holder and the disk. In a state where no such force is generated, the flying force generated in the head or head holder, the distance between the head and the disk, and the side force generated in the radial direction from the center of the disk are measured.

[Operation] According to the above method, it is possible to measure the frictional force and surface pressure generated between the disk and the head by rotating the disk in such a way that friction occurs between the disk and the head or the head holder that holds it. .

■It is possible to measure the distance between the disk and the head by rotating it without causing any friction, and at the same time measure the levitation force generated on the head.

(2) In the measurements of (2) and (2) above, the force (side force) generated in the radial direction from the center of the disk can be measured at the same time.

[Embodiment] Fig. 1 is a block diagram showing a schematic configuration of main parts in an embodiment of the present invention. In the figure, l is a sensor amplifier and a signal processing circuit, 2 is a system control circuit that performs signal amplification and calculation of force S; 3 is a motor for rotating the disk; 4 is a motor drive circuit for rotating the disk; 5 is a motor that moves the head in the radial direction from the center of the disk; the motor drive circuit 6. 7 is a disk, 8 is a sensor for measuring the distance between the head 9 and the disk 7, 9 is a head held in a head holder, and has sensors for measuring surface pressure or levitation force R9 frictional force F, and side force S. We are prepared.

FIG. 2 is a perspective view showing the disk, head, and head holder in the embodiment of FIG. 1, in which 9R represents a surface pressure or levitation force sensor, 9F represents a friction force sensor, and 9S represents a side force sensor. ing.

Next, the operation shown in FIG. 2 will be explained. When the disk 7 is rotated with friction occurring between the disk 7 and the head 9, the surface pressure R acting between the disk 7 and the head 9 is measured by a sensor in the surface pressure direction of the levitation force sensor 9R. The frictional force F at that time is measured by the frictional force sensor 9F''?! Also, the side force S generated at the same time as the disk 7 starts to rotate is measured by the side force sensor 9S. These measured values are The input is input to the sensor amplifier and signal processing circuit l shown in Fig. 1, and amplification and calculations are performed. It can be determined by performing calculations based on the measured values.

Next, when the disk 7 is rotated in a state where no friction occurs between the disk and the head 9, a floating force R is generated corresponding to the distance of the gap between the disk 7 and the head 9, and this force is
It can be measured with the levitation force sensor 9R. At this time, side force S and friction force F are also generated, although they are small.
Each can be measured as described above.

As described above, according to the present invention, the friction coefficient can be accurately measured in a state where the frictional force F is generated between the disk 7 and the head 9. Further, in a state where no frictional force F is generated, the flying force of the head 9 and the distance between the head and the disk, that is, the flying force R can be accurately measured. Also, in both conditions, side force S (generally disc 7
At the same time as the rotation of the disk 7, the force directed toward the center of the disk 7 can also be measured.

[Effects of the Invention] As described above, according to the method of the present invention, the frictional force, surface pressure, and side force between the disk and the head can be accurately grasped, so the measurement accuracy of the friction coefficient and generated force is improved. It is effective.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a schematic configuration of main parts in an embodiment of the present invention, FIG. 2 is a perspective view showing a disk, a head, and a head holder in the embodiment of FIG. 1, and FIG. ) is a plan view of the device showing the conventional measurement method;
b) is a cross-sectional view taken along line B-H in FIG. In the figure. l: Sensor amplifier and signal processing circuit 2 System control circuit 3: Disk rotation motor 4: Disc rotation motor drive circuit 5: Head movement motor 6: Motor drive circuit 7: Disk 8: Dial indicator 9: Head and Head holder 9R: Surface pressure or levitation force measurement sensor 9F: Friction force measurement sensor 9S: Side force measurement sensor Representative Patent attorney 1) Haru Kitatake Figure 1 Figure 2

Claims (1)

[Claims] A levitation force sensor that measures the levitation force in the disk surface pressure direction on the head or a head holder that holds the head; a friction force sensor that measures the frictional force generated between the head or head holder and the disk; By providing a side force sensor for measuring the side force generated in the radial direction from the head and a means for measuring the distance between the head or head holder and the disk, in a state where friction with the disk occurs, Accurately measure the coefficient of friction and changes in the coefficient of friction, and when there is no friction between the head or head holder and the disk, calculate the flying force generated on the head or head holder and the distance between the head and the disk. A method for measuring the force and coefficient of friction generated between a disk and a head, characterized by measuring the side force generated in the radial direction from the center of the disk.