JPS6370149A - Apparatus for measuring friction factor between magnetic disc and magnetic head - Google Patents

Abstract

PURPOSE:To measure a friction factor at a high accuracy with simple operation, by transmitting a friction force of a contact surface as intact in the tangential direction of a track to detect. CONSTITUTION:A slider 4 is interlocked with the bottom of a fulcrum member 2 mounted at the tip of an arm 1 through an elastic body 3 and placed on the top surface of a magnetic disc D. A balancer 5 is attached to the fulcrum member 2 by being positioned within a vertical plane passing through the axis center of the arm 1 to uniformize a load distribution of the contact surface between the slider 4 and the magnetic disc D. A fine load converter 6 is connected to the rear end of the arm 1 through a hook 7 by being positioned within a vertical plane containing the axis center. The arm 1 and the fine load converter 6 are made to align in the tangential direction of a track of the magnetic disc D being inspected and the slider 4 is abutted on the top of the disc D to detect a friction force of the contact surface thereof with the fine load converter 6 through the arm 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for measuring the coefficient of friction of a contact surface between a magnetic disk and a magnetic head.

[Conventional technology]

Measuring the coefficient of friction of the contact surface between a magnetic disk and the magnetic head that comes into contact with the surface of the disk during recording/playback operations is
(This is one of the important management items for d-disk quality.

As means for measuring the coefficient of friction between a magnetic disk and a magnetic head, those shown in FIGS. 3 to 5 are used.

The measuring device shown in FIG. 3 includes a load cell (10) having a V-shaped notch (11) and a strain gauge (12) attached to its base, and a slider (4) connected to the load cell (10) at the tip. ) to which an arm (13) is attached. The slider (4) is made of the same material as the magnetic disk.
It is a slide with a form. When the slider (4) is placed on the top surface of the magnetic disk (D), which is the object to be examined, and is placed on the rotating spindle (S) and the disk (D) is rotated, the rotating magnetic disk (D) and slider (4)
The slider (4) is displaced in the rotational direction of the magnetic disk (D) due to the frictional force between the contact surfaces with the slider (4), and the V-shaped notch (11) of the load cell (10) is bent due to the bending moment caused by the displacement. Strain gauge (12)
The friction coefficient of the contact surface between the magnetic disk and the slider is determined from the detected value.

FIG. 4 shows a slider (4) placed on the upper surface of a magnetic disk (D) installed on a rotating spindle (S), rotating the rotating spindle (S), and applying torque generated on the rotating spindle (S) to the spindle ( The friction coefficient of the contact surface between the magnetic disk (D) and the slider (4) is determined based on the detected value.

In addition, FIG. 5 shows that the bottomed cylindrical bearing supports the rotary spindle (S) in a non-contact manner by introducing compressed air (a) into the member (15) from the compressed air inlet (16). S
) on the top surface of the magnetic disk (D) installed on the slider (
4), and pull the pulling string (17) that has been wound in advance around the rotating spindle (S).
From the tensile force required to rotate the magnetic disk (D)
The friction coefficient of the contact surface between the slider (4) and the slider (4) is determined.

[Problem that the invention seeks to solve]

The measuring device shown in FIG. 3 does not have sufficient measurement accuracy because the displacement of the slider due to friction with the magnetic disk is small. As a countermeasure, it may be possible to incorporate a mechanism to amplify the displacement, but if the amplification mechanism is installed, the arm balance will deteriorate and the load distribution on the bottom surface of the slider that contacts the magnetic disk will likely become uneven ( Furthermore, the position of the slider relative to the track of the magnetic disk changes, resulting in an off-track or off-cent state, making it impossible to improve measurement accuracy.

In the measuring device shown in FIG. 4, since friction is involved in the rotating spindle of the magnetic disk, accurate measurement is almost impossible.

The measuring device shown in FIG. 5 has excellent measurement accuracy, but its mechanism is complicated and the equipment cost is high.

In view of the above, it is an object of the present invention to provide a measuring device that has high measurement accuracy, has a simple structure, and is inexpensive.

[Means for solving problems]

Magnetic disk-magnetic head friction coefficient 411 according to the present invention
The device includes an arm having a fulcrum member attached to its tip, a slider linked to the lower part of the fulcrum member via an elastic body and placed on the upper surface of a magnetic disk as a subject, and an upper surface of the magnetic disk. a balancer attached to the fulcrum member and located in a vertical plane including the axis of the arm in order to equalize the load distribution on the lower surface of the slider that comes into contact with the arm; and a load transducer as the main components, and the arm and the micro load transducer are bent once in the tangential direction of the track of the subject magnetic disk, the slider is placed on the upper surface of the subject magnetic disk, and the slider is brought into contact with the subject magnetic disk. It is characterized in that the frictional force on the surface is detected by a minute load transducer via the arm.

FIG. 1 (CI in the same figure) showing an embodiment of the measuring device of the present invention.
(II) is a front view and (II) is a side view), (1
) is an arm, (2) is a fulcrum member attached to the tip of arm (1), (4) is a slider located at the bottom of fulcrum member (2), and (5) is attached to fulcrum member (2). The balancer (6) is a minute load transducer connected to the rear end side of the arm (1).

The fulcrum member (2) has a gate-shaped cross section, and a gimbal (3) which is an elastic member is attached to the bottom of the fulcrum member (2). By supporting the slider (4) and the fulcrum member (2)
) has been formed.

A fulcrum member (
The reason for carrying 2) is to prevent the load from being biased when it is directly carried.

The balancer (5) has a weight receiver attached to the fulcrum member (2) so as to be located in a vertical plane passing through the axis of the arm (1), and a weight receiver attached to the member (51). By changing the position of the weight (52) on the member (51), the fulcrum of the balance can be made to approximately coincide with the center of the slider (4), and the support can be made up of a weight (52) placed on the slider (4). ) is uniformly distributed at the center of the slider (4).

A minute load transducer (6) on the rear end side of the arm (1) is located in a vertical plane that includes the axis of the arm (1), and is connected to the arm (1) via a hook (7).

FIG. 2 shows how the device of the present invention is installed when measuring the friction coefficient. (A) is a rotating spindle portion, and (B) is a carry nozzle portion, each of which is placed on a precision surface plate (C). A fulcrum member (2) is mounted on the upper surface of the subject magnetic disk (D) set in the rotating spindle (A).
A slider (4) linked to the carriage part (
A minute load transducer (6) is installed in B), and in this state leveling adjustment of the entire measuring device is achieved. Further, the apparatus of the present invention is installed so as to coincide with the tangential direction of the track of the magnetic disk (D), which is the object to be examined, as shown in FIG. 2 (II).

When the device of the present invention is installed on the subject's corporal punishment disk in this way and the magnetic disk (D) is rotated in the direction of the arrow, the contact surface between the slider (4) and the magnetic disk (D) is Due to the frictional force, the slider (4) moves against the magnetic disk (
D) is dragged in the tangential direction of the track, and the frictional force is transmitted to the minute load transducer (6) via the arm (1) and converted into an electric potential.

[Effect]

In the device of the present invention, the balance fulcrum is adjusted by the balancer, and the slider displacement during measurement coincides with the tangential direction of the track of the d-disk, so the balance fulcrum does not deviate from the slider and the lower surface of the slider The load distribution on the slider is always maintained in a substantially uniform state.Therefore, measurement errors caused by bias in the load distribution on the lower surface of the slider are extremely small.

In addition, since the displacement of the slider is in the tangential direction of the trunk of the disk, off-track of the slider (displacement of the slider in the radial direction of the magnetic disk) due to friction with the magnetic disk and the resulting displacement, and offset angle (
The inclination angle of the slider with respect to the tangential direction of the track of the magnetic disk is small, and therefore the measurement error due to offset/off-track of the slider is small.

Furthermore, since there is no rotating part within the measuring device, measurement errors due to friction of the rotating part do not occur.

In this way, measurement errors caused by biased load distribution on the lower surface of the slider, off-track/offcent of the slider, etc. are small, and the relationship between the magnetic disk and the slider is minimized and there is no disturbance caused by friction within the device. The frictional force on the contact surface is
Since the load is transmitted to the minute load transducer and detected in the tangential direction of the track, highly accurate measured values can be obtained.

〔Effect of the invention〕

According to the device of the present invention, the coefficient of friction between a magnetic disk and a magnetic head can be measured with high precision with simple operation. Moreover, the device of the present invention is configured to transmit the frictional force between the magnetic disk and the magnetic head in the track tangential direction to the minute load transducer in the tangential direction, and does not have a rotating part in the device, and has no displacement amplification mechanism. It is a measuring device that has an extremely simple structure, does not require a

[Brief explanation of the drawing]

FIG. 1 (1) Front view showing an embodiment of the measuring device of the present invention, (
II) is a side view, FIG.
5 to 5 are main part explanatory diagrams showing a conventional measuring device and a measurement mode (however, FIG. 3 is a plan view, FIG. 4 is a front view, and FIG. 5 is a partially cutaway front view). 1: arm, 2: fulcrum member, 3: elastic body, 4 varnish slider, 5: balancer, 6: minute load transducer, D = magnetic disk.

Claims (1)

[Claims] (1) An arm with a fulcrum member attached to its tip,
A slider is linked to the lower part of the fulcrum member via an elastic body and is placed on the upper surface of the magnetic disk that is the object to be inspected, and the arm is arranged to equalize the load distribution on the contact surface between the slider and the magnetic disk. The main components include a balancer located in a vertical plane passing through the axis of the fulcrum member and attached to the fulcrum member, and a minute load converter connected to the rear end side of the arm, and the arm and minute load converter. The slider is brought into contact with the upper surface of the magnetic disk to be tested by aligning the slider with the tangential direction of the track of the magnetic disk to be tested, and the frictional force on the contact surface is detected by the minute load transducer via the arm. A magnetic disk-magnetic head friction coefficient measuring device characterized in that: