JPS62124680A - Head positioning mechanism - Google Patents

Abstract

PURPOSE:To heighten efficiency of utilization of an electric conductor and reduce leakage magnetic field by providing an electric conductor consisting of six specific sides, the first-the sixth, applying current to the conductor, and generating specific driving force by the magnetic field and flow of current. CONSTITUTION:An end sides are connected to each other and made to the first side 7a and the second side 7b and provided on a face parallel to the face of the direction of moving of a movable body 3. The third side 7c and the fourth side 7d consisting of electric conductors 7 that end sides are connected to each other and parallel to the first side 7a and the second side 7b are provided. Another end sides of the first side 7a and the third side 7c are connected at nearly right angles, and the fifth side 7e consisting of electric conductors 7 that intersect at nearly right angles to the direction of movement of the movable body 3. Similarly, the sixth side 7f is provided by the second side 7b and the fourth side 7d. A magnetic field is interlinked to at least one side of the electric conductor 7, and driving force is generated to move the movable body 3 by applying current to the electric conductor 7. Thus, efficiency of utilization of the electric conductor 7 is heightened, leakage magnetic field is reduced and malfunction of the head is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a head positioning mechanism that is mounted on, for example, a magnetic disk drive and performs high-speed positioning with respect to a magnetic disk.

[Prior Art] As a conventional head positioning mechanism of this type, for example, the first
There is something like the one shown in Figure 0. This is the swing axis 101,
An arm 105 with a magnetic head 103 attached to its tip is swingably provided, and a coil 107 is wound around the base of the arm 105 on the opposite side of the swing axis 101 from the magnetic head 103. A rectangular coil support 109 is coupled. A magnet 113 is inserted into the coil support 109 and is attached to a yoke 111 fixed to the housing side (not shown), and together with this yoke 111 constitutes a magnetic circuit that applies a magnetic field to the upper and lower long sides 107a of the coil 107. has been done.

In such a configuration, when a current is passed through the coil 107, the coil 107 is caused by this current and the magnetic field generated by the magnetic circuit.
A force that causes the arm 105 to swing around the swing shaft 101 is received. As a result, the magnetic head 103 is positioned in a predetermined manner with respect to the magnetic disk (not shown).

Moreover, FIG. 11 shows a head positioning mechanism showing another example. This is a magnet 1115.117 with opposite polarity to each other.
is placed on a yoke 119 that forms a magnetic circuit with the magnets 115 and 117, and the member that forms the magnetic circuit, with the magnet attached to the yoke, is placed so as to sandwich the coil 123 attached to the arm 121 from both sides. The coils 123 are arranged on both sides of the coil 123. In this case as well, by applying current to the coil 123, the arm 121 swings about the swing shaft 125, and the magnetic head 127 is positioned at a predetermined position with respect to the magnetic disk (not shown).

[Problem to be Solved by the Invention 1] However, in the mechanism shown in FIG. 10, since the magnetic field is applied only to the upper and lower long sides 107a of the rectangular coil 107, the driving force is applied only to the long sides 107a. occurs, and no driving force is generated in the short side portions 107b on both sides.Furthermore, in this case, the length of the coil 107 is a long coil type that is longer than the length of the magnet 113. No driving force is generated even in long parts, and as a result, the wire length of the coil that generates the driving force becomes extremely short compared to the total coil wire length, resulting in extremely low coil utilization efficiency. There's a problem.

Furthermore, since the coil wire is wound around the part of the coil support 109 that is connected to the base of the arm 105 (the short side 107b on the swing shaft 101 side), the connection of the coil support 109 to the base of the arm 105 is prevented. The problem is that it is difficult to consolidate power.

Furthermore, since the magnetic circuit of this example has a long coil type as described above, it is necessary to increase the strength of the magnetic field interlinking with the coil 107, and therefore the magnetic field within the yoke 111 cannot be brought to a state close to saturation. There are many and York 11
1 and the magnet 113, the leakage magnetic field increases, and it is necessary to install a shield plate to prevent it from affecting the magnetic head 103.

On the other hand, also in the mechanism shown in FIG.
23b only, side 123C.

Since no driving force is generated in 123d, it is undeniable that the utilization efficiency of the coil is reduced. In particular, since the side 123C is long, it not only promotes the invalid length of the coil wire, but also increases the length of the arm 121C.
There is a problem of increasing the rotational inertia of the

The present invention was devised in view of these conventional problems, and aims to provide a head positioning mechanism that increases coil utilization efficiency and reduces leakage magnetic fields.

[Means for Solving the Problems] In order to achieve this object, the present invention provides a movable body in which a recording/reproducing head (11) is mounted and movable relative to a recording medium, and a conductor attached to this movable body. and a magnetic circuit for moving the movable body by applying a magnetic field to the conductor, wherein the conductor extends in a direction substantially perpendicular to the moving direction of the movable body and is connected to each other at one end. Provided as a first side and a second side on one surface parallel to the moving direction plane of the movable body, and parallel to the first side and second side, respectively, on the other surface and connected at one end side to each other. a third side and a fourth side made of a conductive material, the other end sides of the first side and the third side are connected to these two sides at a substantially right angle, and a movable body is provided. A fifth side made of a conductor is provided that is substantially orthogonal to the moving direction of the
A sixth side made of a conductor is connected to the other ends of the second side and the fourth side at a substantially right angle to these two sides and is substantially perpendicular to the moving direction of the movable body. A magnetic circuit is provided that interlinks a magnetic field with at least one side of the conductor and generates a driving force to move the movable body by energizing the conductor.

[Effect] When a current is passed through a conductor consisting of six sides (first side to sixth side), a magnetic field is generated in a magnetic circuit on each side, and the force acting on each side due to the magnetic field and the current flow is It occurs so that the direction is the direction of movement of the movable body. As a result, the movable body moves and the recording/reproducing head is positioned at a predetermined position on the recording medium.

[Example 1] Hereinafter, a detailed explanation of the present invention will be given based on FIGS. 1 to 9.

FIGS. 1 to 5 relate to a head positioning mechanism of a magnetic recording apparatus which is an embodiment of the present invention, and the structure thereof will first be explained.

An arm 3 having a recording/reproducing head (hereinafter simply referred to as a head) 1 attached to its tip is swingable about a swing shaft 5 . A coupling portion 9a of a coil support 9 incorporating a coil (conductor) 7, which will be described later, shown in FIG. 2 is firmly coupled to the base 3a side of the arm 3 on the side opposite to the head 1 by an appropriate method. . The coil support 9 swings together with the arm 3 and has a hollow shape with openings on both sides in the swinging direction. The coil support body 9 and the arm 3 constitute a movable body.

The coil 7 has a shape as shown in FIG. That is, the coil wire of this coil 7 has a first side 7a and a second side 7b extending in a direction perpendicular to the direction of movement of the coil support 9 at an appropriate angle to each other in the radial direction about the swing axis 5. They are provided on one side (the upper side in FIG. 2) 9b parallel to the moving direction of the coil support 9 with one ends connected to each other. Also, in FIG. 2, the coil support 9
On the other surface 9c, which is the lower surface of the
Similarly to the mutual connection state of the sides 7a, 7b and the arrangement state of the first and second sides 7a, 7b to the one side 9b,
A third side 7c and a fourth side 7d are provided, respectively.

The other ends of the first side 7a and the third side 7G are connected by a fifth side 7e that is perpendicular to these two sides and perpendicular to the moving direction of the coil support 9. Base 9a
It is installed at 9d on the opposite side. Further, the other ends of the second side 7b and the fourth side 7d are connected by a sixth side 7f that is perpendicular to these two sides and perpendicular to the moving direction of the coil support 9. Similar to the side 7e, it is provided on the surface 9d of the coil support 9 opposite to the base 9a.

These are the first to sixth sides 7a, 7b, 7c, and 7d.

In the coil 7 composed of 7e and 7f, the coil wire goes from the first side 7a to the fifth side 7e to the third side 7C to the fourth side 7.
d→sixth side 7f→second side 7b→first side 7a→...
It is wound in the order of...

The member 11 consisting of the coil 7 and the coil support 9 can be manufactured by forming a substantially hexagonal coil into the shape shown in FIG. 1 by press forming, and then bonding it to the coil support 9. Alternatively, the processed coil 7 is formed integrally with the coil support 9.

FIG. 3 shows a magnet 13 and a yoke 15 made of a magnetic material, which constitute a magnetic circuit for applying a magnetic field to the coil 7 described above. The yoke 15 has a hollow shape and is composed of a yoke main body 15a having an upper surface A, a lower surface and a rear surface C opposite to the swing shaft 5, and side yokes 15b and 15C, and is supported by both side yokes 15b and 15c. At the same time, a center yoke 15d is disposed with a gap provided between the upper surface A and the lower surface B, respectively.

A pair of magnets 13 as shown in FIG.
(13a, 13b) are provided.

That is, the magnet 13a on one side yoke 15b side is
A surface 13a1 consisting of an N pole that contacts the upper surface A, and this surface 1
Continuing from the edge on the rear surface C side of 3a1, there is a N-pole 13a2 which is bent at right angles to the surface 13a1, and a N-pole 13a2 is continuous from this surface 13a2 by being bent at right angles in the same direction as the N-pole surface 13a1, and a surface 13a3 consisting of an N pole that contacts the lower surface B. Further, the magnet 13b on the other side yoke 15c has the same shape as the magnet 13a, and the magnet 1
The surfaces 13b+ and 13b2 and 13b3 that are close to the surfaces 13a+ and 13a2 and 13a3 of 3a, respectively, are S poles.

Then, as shown in FIG. 5, the coil support 9 to which the coil 7 is attached is movable relative to the yoke 15 so as to be able to swing around the swing shaft 5, and the center yoke 15d is placed inside the coil support 9. is inserted.

At this time, the magnets 13a, 13b] each of the first to sixth sides 7a, 7b, 7c, 7d, 7e of the tile 7.

7f, a magnetic field is generated in the direction of the broken line arrow perpendicular to each side, as shown in FIG. In this state, when no current is applied to the coil 7 in the direction of the solid line arrow, the arm 3 and the coil support are connected to each of the first to sixth sides of the coil 7, with the swing shaft 5 as the center in a direction perpendicular to each side. A force is applied in the swing direction 9, and the head is positioned at a predetermined position on a magnetic disk (not shown).

Therefore, in this case, since the driving force acts on most parts of the coil 7, there are almost no ineffective parts of the coil 7, and the coil utilization efficiency is extremely high. Furthermore, in this magnetic circuit, since the magnets 13a and 13b are opposed to the coil 7 with a gap in between, the leakage magnetic field toward the swing shaft 5 side where the yoke 15 is open is reduced. Furthermore, since the yoke 15 is provided on the side and rear surfaces, the leakage magnetic field to the side and rear surfaces is extremely small.

In addition, the coupling of the coil support body 9 to the arm 3 is strong because no coil is interposed as in the conventional case, and therefore the rigidity of the movable body is improved and the mechanical resonance frequency can be increased. High-speed and highly accurate positioning of the head 1 becomes possible.

FIGS. 6 and 7 show a second embodiment. In this embodiment, the tip (head 1) can be adjusted by bending the arm 3.
The side is arranged on the side of the side yoke 15c. Furthermore,
A notch 17 is formed in the side yoke 15c, and a reinforcing side 9e that protrudes toward the side yoke 15c is provided at the end of the coil support 9 opposite to the coupling surface 9a. This reinforcing periphery 9e protrudes from the notch 17 to the outside, and its tip is fixed to the arm 3. As a result, the coil support body 9 is reinforced, a movable body with a high mechanical resonance frequency can be constructed, and high-speed and highly accurate positioning is possible. Also, since arm 3 is bent,
The total length of the mechanism itself can be shortened.

FIGS. 8 and 9 show a third embodiment. In this embodiment, the arm 3 is bent like the second embodiment described above, and the side yoke is only one side yoke 15b, while the coil support 9 is formed into a substantially triangular shape and is connected to the arm 3. The surface 9a is made wide to strengthen the connection between the coil support 9 and the arm 3. This makes it possible to configure a movable body with a high mechanical resonance frequency. Also in this embodiment, since the arm 3 is bent, it is possible to shorten the overall length of the mechanism itself.

Note that the present invention is not limited to each of the above-described embodiments. For example, the coupling portion of the coil support 9 to the arm 3 may be formed on both upper and lower surfaces 9b and 9c, and the coupling surface 9a may be removed.
Each surface on which the coil 7 is provided, such as b and 9c, may have a C-shaped side surface having a constant curvature centered on the swing axis 5 side.

Furthermore, in each of the above embodiments, the magnetic field to the coil 7 is
Although it is given to each of the sixth sides, it may be given only to a pair of sides on the same plane, for example, the first side 7a and the second side 7b,
Alternatively, it may be applied to the two sets of sides above.

Furthermore, the side yokes can be
It may also be made of non-magnetic material.

[Effects of the Invention] As described above, according to the present invention, the utilization efficiency of the conductor is increased, and malfunction of the head can be prevented by reducing the leakage magnetic field, and a high-speed, high-precision head can be operated with low power consumption. Positioning control becomes possible.

[Brief explanation of drawings]

Figures 1 to 5 relate to one embodiment of the present invention, with Figure 1 being a perspective view of the coil, Figure 2 being a perspective view of the coil mounted on a coil support, and Figure 3 being a perspective view of the yoke. , FIG. 4 is a perspective view of the magnet, FIG. 5 is a perspective view of the head positioning mechanism, FIGS. 6 and 7 are related to the second embodiment, FIG. 6 is a perspective view of the head positioning mechanism, and FIG. 7 is a perspective view of the head positioning mechanism. The figure is a perspective view of the coil and the coil support, FIGS. 8 and 9 relate to the third embodiment, FIG. 8 is a perspective view of the head positioning mechanism, and FIG. 9 is a perspective view of the coil and the coil support. 10 is a perspective view of a conventional head positioning mechanism, and FIG. 11 is a plan view of another conventional head positioning mechanism. 1... Recording/reproducing head 3... Arm (movable body) 7... Coil (conductor) 7a... First side 7b... Second side 7C.
...Third side 7d...Fourth side 7e...Fifth side 7f...Sixth side 9...Coil support movable body) A...Top surface (one side ) B...Bottom surface (other surface)
C... Rear surface/d Fig. 2 Lnu'') Fig. 5 Fig. 6 Fig. 7 Fig. 10 Fig. 07b Fig. 11ゝ107a 125123d (T::.

Claims (1)

[Claims] A head positioning mechanism having a movable body to which a recording/reproducing head is attached and movable relative to a recording medium, a conductor attached to the movable body, and a magnetic circuit that applies a magnetic field to the conductor to move the movable body. , the conductors are extended in a direction substantially perpendicular to the direction of movement of the movable body, and one end side thereof is connected to each other, and provided as a first side and a second side on one surface parallel to the plane in the direction of movement of the movable body. In addition, a third side and a fourth side made of a conductor are provided on the other surface, parallel to the first side and the second side, respectively, and connected to each other at one end side, and the first side and the fourth side are provided on the other side. A fifth side made of a conductor is provided, the other end side of which is connected to these two sides at a substantially right angle, and is substantially orthogonal to the moving direction of the movable body, and The other end side of the fourth side,
A sixth side made of a conductor is provided which is connected to these two sides at a substantially right angle and is substantially orthogonal to the moving direction of the movable body, and a magnetic field is interlinked with at least one side of the conductor to energize the conductor. A head positioning mechanism characterized by being provided with a magnetic circuit that generates a driving force to move a movable body.