JPS63225969A - Magnetic disk driving device - Google Patents

Abstract

PURPOSE:To enable the followable displacement upon a magnetic disk in its undulation, etc., by supporting 1st and 2nd magnetic heads with gimbal plates respectively to be capable of rolling and pitching and making on the other hand the 2nd gimbal plate indisplacible in the direction of Z axis against a head arm. CONSTITUTION:When the head arm 3 is descended and the magnetic head 21 is brought into contact with the magnetic disk D on its side 1 surface, the magnetic head 21 is supported by the gimbal plate 22, but the displacement in the direction of Z axis is infeasible due to a protrusion 25a of a butt member 25 provided on the head arm 3, so that the magnetic heads 14 and 21 are brought under the state of dynamic stability by pinching the magnetic disk D. When the magnetic disk D is displaced microscopically in the direction of Z axis from the above state, the magnetic head 21 is then displaced in the direction of Z by the movement of the head arm 3 of its own while the magnetic head 14 is displaced in the direction of Z axis so far as an allowable range of an elastically supported push-up member 18 to follow up the displacement of the magnetic disk D very well.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a drive device for a flexible magnetic disk called a J-floppy disk, and particularly to a magnetic head support mechanism thereof.

<Prior Art> As is well known, in a double-sided floppy disk drive, a first magnetic head that comes into contact with the side 0 side surface of the magnetic disk and a magnetic disk are mounted on a kisser ridge that is transported along the radial direction of the magnetic disk. A second magnetic head is mounted which comes into contact with the side L side surface of the magnetic head. The first magnetic head is attached to a carriage base, and the second magnetic head on the other side is attached to an (upper) head arm whose one end is held by the carriage base so as to be able to move up and down. installed.

In addition, the above head arm is controlled by the head arm spring.
The second magnetic head is given a biasing behavior in the direction in which it is pressed against the first magnetic head, and when no magnetic disk is attached, it is lifted up by the lift-up means as appropriate against the head arm spring. When the magnetic disk is mounted, the lift-up means is released and the second magnetic head is pressed against the first magnetic head via the magnetic disk.

In the above configuration, the first magnetic head is normally held so as not to be substantially displaced in the Z-axis direction (direction perpendicular to the plane of the magnetic disk), and the second magnetic head is held in the Zinpulp notebook. Retained. This cymbal cooperates with the head arm spring to cause the second magnetic head to roll and pitch while closely contacting the disk surface, following the minute fluctuations in the disk plane when the magnetic disk rotates. It has become,
This ensures predetermined read/write characteristics.

<Problems to be Solved by the Invention> Incidentally, in the conventional configuration described above, although the second magnetic head on the gimbal plate is pressed toward the first magnetic head side by the head arm spring, the first magnetic head Since the head does not change in the above-mentioned Z-axis direction, there is a possibility that the magnetic disk may sometimes be temporarily separated from the first magnetic head due to waviness or deformation of the magnetic disk.
There was a fear that this would lead to a so-called run-out.

<Objective of the Invention> Therefore, the technical problem to be solved by the present invention is to eliminate the above-mentioned conventional drawbacks, and the purpose thereof is to enable the magnetic heads on both sides to closely follow the undulations of the magnetic disk and to prevent run-out. To provide a B1 disk drive device which can reduce the occurrence of such occurrences and can always expect good head touch.

<Means for Solving the Problems> In order to achieve the above-mentioned object, the magnetic disk drive device of the present invention includes a carriage that transports a flexible magnetic disk along the radial direction, and a carriage base of the carriage that moves the flexible magnetic disk. a first magnetic head that is in sliding contact with the side surface of the side O of the magnetic disk; and a head arm that is attached to the carriage base so as to be able to move vertically by a predetermined amount, and a first magnetic head that is in full contact with the side surface of the site L of the magnetic disk. a head arm pressing means for pressing the second magnetic head together with the magnetic disk toward the first magnetic head;
A first gimbal plate holding the first magnetic head is attached to the carriage base, and the first gimbal plate holds the first magnetic head.
a magnetic head capable of rolling and pitching by a predetermined amount, and also capable of displacing a predetermined amount in the Z-axis direction perpendicular to the magnetic disk surface; and approximately the center of the surface of the first gimbal plate opposite to the surface facing the magnetic disk. a push-up member that abuts the position and is supported by an elastic support means, thereby allowing displacement of the first magnetic head in the Z-axis direction; and a second gimbal that holds the second magnetic head. a plate which is attached to the head arm and allows the second magnetic head to roll and pitch by a predetermined amount; and a substantially central position of the surface of the second gimbal plate opposite to the magnetic disk facing surface. and an abutment member integral with the head arm that abuts the head arm, thereby making it substantially impossible for the second magnetic head to be displaced in the Z-axis direction with respect to the head arm.

Effects> In the configuration of the present invention, when the head arm is lifted up, the height of the gap surface of the first magnetic head is increased by the second magnetic head via the magnetic disk, as described later. It is in a static stable state at a position that is as high as it is pushed and sinks. That is, when the head arm is lifted up, the gap surface of the first magnetic head is in a static stable state with a positional relationship that slightly pushes up the magnetic disk. Then, when the magnetic disk is attached, the head arm is lowered, and the second magnetic head is in contact with one side of the magnetic disk, the second magnetic head is held by the second gimbal plate. Since the head arm cannot be displaced in the Z-axis direction, the first magnetic head sinks slightly due to the pressing force of the second magnetic head by the pressing means (head arm spring), and the first magnetic head The second magnetic head, while holding the magnetic disk, assumes a dynamically stable state at a position where the downward force of the pressing means, the upward force of the elastically supported pushing up member, and the reaction force of the magnetic disk are balanced.

In other words, the macroscopic dynamic balance position of both magnetic heads in the Z-axis direction when the magnetic disk is rotationally driven is determined by the above-mentioned dynamic stable state, and when there is a slight Z-axis displacement in the magnetic disk, the elasticity The first gimbal plate whose center is abutted against the supported push-up member
The magnetic head and the second magnetic head on the head arm, which is supported by a leaf hinge and is movable up and down, are both movable up and down in the Z-axis direction, so both magnetic heads are in close contact with the magnetic disk with appropriate clamping force. The head easily follows the magnetic disk and moves up and down minutely, and from a microscopic point of view, the balance position in the Z-axis direction changes moment by moment to ensure stable head touch.

Note that the second magnetic head moves Z due to the movement of the head arm itself.
The first magnetic head is displaced in the Z-axis direction within a relatively small range allowed by the elastically supported push-up member, and the movement of the upper and lower magnetic heads is not symmetrical and has a resonance natural frequency. are different, so even if vibration is applied from the outside, there is no risk of the amount of displacement in the Z-axis direction being amplified unnecessarily.
There is no off-track tendency.

In addition, both the first and second magnetic heads are supported by a gimbal plate and are capable of rolling and pitching, so they can follow the minute tilting of the magnetic disk well, and in combination with the above-mentioned tracking ability in the Z-axis direction, the head Touch, ie good read/write characteristics can be achieved.

Furthermore, if the above-mentioned push-up member is made of a vibration-absorbing material, the occurrence of head resonance can be suppressed as much as possible.

<Example> The present invention will be explained below with reference to an example shown in FIGS. 1 to 8. Figure 1 is a cross-sectional side view of the main part of the carriage taken along a plane perpendicular to the carriage transport direction, Figure 2 is a cross-sectional side view of the main part taken along a plane along the carriage transport direction, and Figure 3 is a cross-sectional side view of the main part taken along a plane perpendicular to the carriage transport direction.
4 is a side view of the carriage, FIG. 5 is an exploded perspective view of the support mechanism of the first magnetic head, and FIG. 6 is a view of the first magnetic head and the first gimbal plate. 7 is a back view showing the second magnetic head and the second gimbal plate, and FIG. 8 is an explanatory diagram of the operation.

The entire structure is shown in Fig. 3.4, and the carriage is generally designated by the reference numeral l, and is mainly comprised of a carriage base 2 made of plastic such as polycarbonate, and a head arm 3. Reference numeral 4.5 denotes a guide shaft, which is fixed to the main body of the magnetic disk drive device (not shown) with precise parallelism. Then, the carriage base 2 is inserted through the guide shaft 4.5, and the entire carriage l is transported along the shaft 4.5 in the Y direction in FIG. 3, that is, in the radial direction of the flexible magnetic disk. ing. Although not shown in the drawings, the means for transporting the carriage 1 is a known method, such as converting the rotation of a stepping motor into linear motion using a steel belt and transmitting it to the carriage 1. Note that although one of the guide shafts 4 is not shown in the drawings, two bearings of the carriage base 2 are inserted into holes, and the other guide shaft 5 is inserted into a shaft holding portion 6.6 on the side of the carriage base 2. It is inserted into the bolt.

Reference numeral 7 denotes an arm pedestal portion of the carriage base 2 (FIG. 4), the surface of which is formed as a highly accurate flat surface, and a 2M female threaded bushing (not shown) is embedded therein. Reference numeral 8 denotes a leaf hinge made of a thin metal plate with spring properties, and a portion thereof is embedded and fixed in the base end of the head arm 3 by insert molding.

This leaf hinge 8 is firmly attached to the arm pedestal 7 together with a metal fitting 9 by means of a screw 10 which is screwed into the threaded bushing. The head arm 3 is attached to the carriage base 2 so as to be vertically movable by a predetermined amount within the range in which the leaf hinge 8 is elastically deformed.

11 is a head arm spring made of a torsion coil spring,
The coil portion 11a is held by a spring support portion 9a provided on the metal fitting 9, and its end 11b is brought into elastic contact with the spring receiver 12 of the head arm 3, and the other end 11c is attached to the spring support portion 9a provided on the metal fitting 9. is brought into elastic contact with the stepped portion of the metal fitting 9. Although this head arm spring 11 has a rotation bias in the direction in which the free end side of the head arm 3 comes into contact with the carriage base 2 (clockwise direction in FIG. 4), when a magnetic disk is not attached, the head The arm 3 has its finger 13 supported and lifted up by a known appropriate lift-up means, and the head arm 3 is supported by the head arm spring 1.
It is in a state of being lifted up against 1.

No. 1.2.5.61! As shown in FIG. 1, the first magnetic head 14, which is attached to the upper surface of the carriage base 2 and makes sliding contact with the side 0 surface of the magnetic disk, is attached to the carriage base 2 via a first gimbal plate 15. The first gimbal brake) 115 has a plate thickness of 0.
．． It is made of a thin stainless steel spring plate of about 0.05 to 0.1 mm, and has cut grooves 15a to 15d, reference holes 15e and 15f for mounting jigs, and a cut of 1.
Central movable plate portion 15g formed by 5c and 15d
is formed. The known bulk-type first magnetic head 14, which is accurately positioned in the through hole of the central movable plate portion 15g, is fixed to the first gimbal plate 15 with an adhesive. The main body portion 14a has a sliding surface with a gap on the upper surface side,
Further, the coil portion 14b (FIGS. 1 and 2) of the first magnetic head 14 and the like are located on the back side of the first gimbal plate. Note that 16 is a flexible printed circuit board connected to the first magnetic head 14.

Central movable plate portion 15g of the first gimbal brake) 15
Due to the presence of the known grooves 15a to 15d, the first magnetic head 14 attached to the magnetic head 14 can roll in the direction of arrow R in FIG. 5 (rotation perpendicular to the head transport direction Y),
It is movable by pitching in the direction of arrow P (rotation perpendicular to the disk transport direction X) and by a predetermined amount in the Z direction (height) perpendicular to the disk surface. Then, the first gimbal brake (15) supporting the first magnetic head 14 in this manner
In this case, the support of the carriage base 2 is precisely positioned in the part 17 (Fig. 1.2), and the fiBI
7 with adhesive.

Reference numeral 18 denotes a push-up member, which is made of synthetic resin such as polycarbonate, Delrin, elastic synthetic resin, rubber, etc. In any case, a material with better vibration absorption properties than metal is selected, and these materials are suitable for shooting against the gimbal. Elastic synthetic resins and rubbers are selected to function as dynamic absorbers and to further improve their vibration absorbing properties than polycarbonate and Delrin.

This push-up member 18 includes a tapered flat plate portion 18a, a protrusion 18b that receives a pot and comes into contact with the center of the back surface of the first gimbal brake (15), and a bottle 18 for mounting.
c, 18c are integrally formed.

19 is a support leaf spring serving as an elastic support means for bringing the protrusion 18b of the push-up member 18 into contact with the first gimbal plate 15, and has a plate thickness of, for example, 0.05 to 0.15-0.
It is made of thin stainless steel spring plate. The support plate spring 19 is formed into a narrow strip shape, and holes 19a, 1 in the center thereof are formed.
The pin 18c of the push-up member 18 is inserted into the push-up member 9a, and the push-up member 18 is attached to the support plate spring 19 in close contact with the support plate spring 19. If necessary, the push-up member 18 is fixed with an adhesive, heat caulking, or the like. When the push-up member 18 is attached, the tongue piece 19 protruding from the center side of the support plate spring 19 is attached.
b comes into contact with the lower part of the protrusion 18b of the push-up member 18.

Incidentally, 19c and 19d are mounting holes for positioning the support plate spring 19, which are bored at both longitudinal ends of the support plate spring 19.

The support plate spring 19 to which the push-up member 18 is attached as described above is attached to the receiving portion 20 (the first
．． (Fig. 2) and fixed at both ends. That is, the support plate spring 19 is attached at both ends through the holes 1.
9c, 19d, the projections 20a, 20a of the above-mentioned receiver part 20
is inserted and positioned, and then both longitudinal ends are fixed with adhesive. In this installation state, the protrusion 18b of the push-up member 18 comes into contact with the center position of the central movable plate portion 15g of the first gimbal brake (15) (see FIG. 6) to receive a so-called pivot. At the same time, the central movable plate portion 15g, in other words, the first magnetic head 14, is slightly displaced upward.

That is, when the head arm 3 is lifted up, the height of the gap surface of the first magnetic head 14 is as shown by the two-dot chain line in FIG. 8(a) and will be described later. It is made to be in a static stable state at a position that is higher than the dimension by which it is pushed by a second magnetic head (described later) through D. In other words, if the magnetic disk D is mounted while the head arm 3 is lifted up, the first magnetic head 14 will push up the magnetic disk D slightly due to the elastic force of the support plate spring 19. It will be in a static stable state.

As shown in Figure 1.2.7, the head arm 3 described above
A second magnetic head 21 that is attached to the lower surface of the magnetic disk D and makes sliding contact with one side of the magnetic disk D is also attached to the head arm 3 via a second gimbal plate 22 . The second gimbal plate 22 has a substantially similar shape to the first gimbal plate 15 and is slightly smaller, and is made of a thin stainless steel spring plate having a thickness of, for example, about 0.05 to 0.8 m. The second gimbal plate 22 also has a kerf 2 similar to the first gimbal plate 15 described above.
2a to 22d, reference holes 22e and 22f for mounting jigs are bored, and a central movable plate portion 22g formed by cut grooves 22a to 22d is formed.

After the second magnetic head 22, which has the same bulk type head structure as the first magnetic head 14, is accurately positioned on the central movable plate portion 22g, the second gimbal plate 22 is attached with adhesive. The main body portion 21a of the second magnetic head 21 having a gap surface is located on the back side of the second gimbal plate 22 (FIG. 7 is a back view). 2nd on top side
The coil portion 21b (FIGS. 1 and 2) of the magnetic head 21 and the like are located therein. Further, the gap between the second magnetic head 21 and the gap between the first magnetic head 14 is separated by several tracks, for example, 96 TPI when both magnetic heads 14.21 are facing each other. In this case, the separation is equivalent to 8 tracks. Note that 23 is a flexible printed circuit board connected to the second magnetic head 21.

The second gimbal plate 22 to which the second magnetic head 21 is fixed as described above is accurately positioned at the receiving part 24 (Fig. 1.2) on the lower surface side of the head arm 3, and the peripheral part thereof is The receiver is fixed to part 24 with adhesive. And, the installation to this head arm 3 is in the following condition:
The projection 25a of the abutting member 25, which is integrated with the head arm 3, comes into contact with the center of the upper surface of the central movable plate portion 221i of the second gimbal plate 22 (see FIG. 7) as a pivot receiver. . As a result, the central movable plate portion 2
2g1 That is, the second magnetic head 21 is connected to the head arm 3
are not (relatively) displaceable in the Z (axis) direction mentioned above, and the kerfs 22a to 22d and the pivot receiver act on the protrusion 2δa, which is a part of the second magnetic head. 21 is only capable of rolling in the direction of arrow R in FIG. 7 and pitching in the direction of arrow P.

In the configuration of the embodiment described above, the magnetic disk D
is attached and chucked, and the head arm 3 described above is attached.
When the lift-up means of is released by an appropriate means,
The head arm 3 is lowered by the force of the head arm spring 11, and the magnetic disk D is held between the eleventh and second magnetic heads I4.21 in FIG. 1.2.4 and FIG. 8(a). The state shown in the solid line is reached. At this time, when the second magnetic head 2I descends from the state shown by the two-dot chain line in FIG. The magnetic head ' 14 sinks slightly from the above-mentioned static stable position shown by the two-dot chain line in FIG. 8(a), and the first and second magnetic heads 14. At the same time, a dynamically stable state is reached at a position where the downward force of the head arm spring 11, the upward force of the push-up member 18 elastically supported by the support plate spring 19, and the reaction force of the magnetic disk D are balanced. .

The state shown by the solid line in FIGS. 8(a) and 8(b) shows the macroscopic dynamic balance position, which can also be called the expected reference position of the above-mentioned dynamic stable state.

Then, when the magnetic disk D causes a slight displacement in the Z (axis) direction mentioned above from this state, the first magnetic spatula F' 1
4 can be slightly displaced in the Z direction within the allowable range of elastic deformation of the support plate spring 19, and the second magnetic head 21
is supported by the leaf hinge 8 and is movable in the Z direction together with the head arm 3 which is movable up and down with a downward convergence habit. Therefore, both magnetic heads 14 and 21 can tightly contact the magnetic disk D with appropriate pressure. While holding the fj &
It easily follows the displacement of the air disk D in the Z direction and moves up and down minutely. That is, even if the magnetic disk D causes slight displacement in two directions during its rotation, both magnetic heads 14.2
1 is centered on the above-mentioned macroscopic dynamic stable position, while microscopically changing the balance position in the Z direction from time to time, ensuring stable head touch at all times, and making it possible to extremely reduce the occurrence of run-out. There is. Figure 8(b)
The state illustrated by the dotted line and the state illustrated by the two-dot chain line are schematically exaggerated illustrations of the minute downward displacement and minute upward displacement dynamic balance positions in the microscopic sense, respectively.

The second magnetic head 21 is displaced in the Z direction by the movement of the head arm 3 itself, and the first magnetic head 14 is displaced in the Z direction within a relatively small range allowed by the elastically supported push-up member 18. The movement of the upper and lower magnetic heads 14.21 is not symmetrical, and the resonance natural frequencies are different. There is also much less possibility that the amount of displacement in the Z-axis direction will be unnecessarily amplified, and no off-track tendency will occur.

Furthermore, both the first and second magnetic heads 14.21 are supported by the gimbal plate 15.22 and are capable of rolling and pitching as described above.
Even if the magnetic disk D slightly tilts from the position shown by the two-dot chain line to the position shown by the solid line in c), it is well followed by the known action of the second gimbal brake (15), and the above-mentioned Z-axis Coupled with the directional followability, it is possible to guarantee even better head touch, that is, better read/write characteristics.

Effects> As described above, according to the present invention, it is possible to provide a magnetic disk drive device in which the magnetic heads on both sides can closely follow the undulations of the magnetic disk, thereby reducing the occurrence of run-out, and in which good head touch can always be expected. The industrial value is enormous.

[Brief explanation of drawings]

The drawings all relate to one embodiment of the present invention, and FIG. 1 is a cross-sectional side view of the main part of the carriage taken along a plane perpendicular to the carriage transport direction, and FIG. 2 is a main part taken along a plane along the carriage transport direction. A cross-sectional side view, Figure 3 is a plan view of the carriage,
4 is a side view of the carriage, FIG. 5 is an exploded perspective view of the support mechanism of the first magnetic head, FIG. 6 is a plan view showing the first magnetic head and the first gimbal plate, and FIG. The figure is a back view showing the second magnetic head and the second gimbal plate, and FIGS. 8(a) to 8(c) are operation explanatory views.
) is a diagram explaining the static stable state and macroscopic dynamic stable state of the first magnetic head, and FIG. (c) is a diagram illustrating the following minute tilting motion of both magnetic heads. In the figure, D is a magnetic disk, 1 is a carriage, 2 is a carriage base, 3 is a head arm, 4.5 is a guide shaft, 7 is an arm pedestal, 8 is a leaf hinge, 9 is a mounting bracket, and 10 is a mounting bracket. 11 is a head arm spring, 14 is a first magnetic head, 15 is a first gimbal plate, 15a to 5d are cut grooves, 15g is a central movable plate part, 17 is a receiving part, 18 is a push-up member, 18b is a protrusion;
19 is a supporting plate spring, 19b is a tongue piece, 20 is a receiving part, 2
1 is a second magnetic head, 22 is a second gimbal plate, 22a to 22d are grooves, 22g is a central movable plate portion, 2
4 is a receiving portion, 25 is an abutment member, and 25a is a projection.

Claims (2)

[Claims] (1) a carriage that is transported along the radial direction of a flexible magnetic disk; a carriage base of the carriage that has a first magnetic head that slides into contact with the side 0 side of the magnetic disk; a head arm attached to the head arm so as to be vertically movable by a predetermined amount, and having a second magnetic head slidingly in contact with the side surface of the first side of the magnetic disk; a first gimbal plate holding the first magnetic head; the first gimbal plate is attached to the carriage base;
a magnetic head capable of rolling and pitching by a predetermined amount and also capable of displacing a predetermined amount in the Z-axis direction perpendicular to the magnetic disk surface; and approximately the center of the surface of the first gimbal plate opposite to the surface facing the magnetic disk. a push-up member that abuts the position and is supported by an elastic support means, thereby allowing displacement of the first magnetic head in the Z-axis direction; and a second gimbal that holds the second magnetic head. a plate attached to the head arm, and the second
a magnetic head capable of rolling and pitching by a predetermined amount; and an abutment member integral with the head arm that abuts on a substantially central position of the surface of the second gimbal plate opposite to the surface facing the magnetic disk. A magnetic disk drive device comprising: a device that substantially makes the above-mentioned displacement of the second magnetic head relative to the head arm in the Z-axis direction impossible. (2) The magnetic disk drive device according to claim 1, wherein the push-up member is made of a vibration-absorbing material.