JPS6055906B2 - Magnetic head loading mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a magnetic head loading mechanism for loading or unloading a magnetic head onto or from a magnetic recording medium.

FIG. 1 shows a front view of a conventional magnetic head loading mechanism, and FIG. 2 shows a side view of the main parts thereof.

In FIGS. 1 and 2, 1 is a magnetic head assembly;
2 is a magnetic head, 3 is an arm, 4 is a carriage, 5 is a linear solenoid, 6 is a link, 7 is a recovery spring, 7
' is the operating spring, and 8 is the guard bar.

Please refer to FIGS. 1 and 2.

A carriage 4 is movably supported along two guide bars 8 stretched over a magnetic recording medium (not shown). The carriage 4 is appropriately positioned over the magnetic recording medium by moving along the guide bar 8. As shown in FIG. 2, the magnetic head assembly 1 includes a magnetic head 2 therein.
One end of the assembly 1 is attached to the upper surface of the carriage 4 by a means such as a hinge so that it can be opened and closed, and the arm 3 attached to the other end of the assembly 1 can be attached to the upper surface of the carriage 4 by means of a link 6 or the like. By moving the magnetic head assembly 1 up and down with the means, the magnetic head assembly 1 is opened and closed with respect to the carriage 4, and the open state (FIG. 2) is the state in which the magnetic head 2 is unloaded with respect to the magnetic recording medium, and the closed state is the state in which the magnetic head 2 is unloaded with respect to the magnetic recording medium. The situation is as follows. The link 6 is rotatable around the fulcrum 9,
Its left end engages with the arm 3 of the magnetic head assembly 1, and its right end has a recovery spring 7 attached thereto and one end of a movable member 10, as shown in FIG. Note that an operating spring 7'' is stretched between the arm 3 and the carriage 4, and serves as a driving source when the magnetic head assembly 1 closes with respect to the carriage 4.The movable member 10 is made of a magnetic material. , is sucked in by energizing the linear solenoid 5.In other words, it moves upward against the tensile force of the spring 7, and the link 6 rotates counterclockwise around the fulcrum 9, so that the link 6 The left end is lowered. Therefore, the arm 3 that was engaged with the left end is also lowered by the force of the operating spring 7'', the magnetic head assembly 1 closes against the carriage 4, and the magnetic head 2 is moved by the magnetic head (not shown). Loaded onto the recording medium. When the solenoid 5 is no longer energized, the right end of the link 6 is lowered by the restoring force of the recovery spring 7, and the left end of the link 6 is raised, moving the arm 3 against the force of the operating spring 7'' as shown in FIG. Since it is lifted as shown, the magnetic head 2 becomes unloaded with respect to the magnetic recording medium.The conventional magnetic head loading mechanism as described above has a problem.

One of them is that, as can be seen from FIG. 1, the link 6 rotates about the fulcrum 9, while the movable member 10 moves up and down when pulled out by the spring 7 sucked into the linear solenoid. Performs linear motion in the direction.
Since the lower end of the movable member 10 is coupled to the right end of the link 6, as the link 6 rotates, it not only moves up and down, but also slightly moves horizontally and horizontally. Due to the movement of such a horizontal component, the movable member 10
When moving up and down inside the linear solenoid 5, the movable member 10 and the solenoid 5 tend to have a slight inclination, and the relative movement between the movable member 10 and the solenoid 5 tends to be uneven. In other words, if the solenoid becomes unsmooth, it may generate abnormal noise during operation, or even become inoperable, so linear solenoids are reliable enough. Tenakatsuta. On top of that,
Implementing a linear solenoid also has the disadvantage of increasing the size of the device. The second problem is that when a magnetic head is loaded onto a magnetic recording medium, a collision occurs between the two.

In recent years, flexible magnetic disks have been developed and used in which a flexible material such as a Mylar sheet is used as a substrate, coated with a magnetic material to form a disk shape, and housed in a jacket made of plastic. A disk is used with a pair of magnetic heads pressed against both sides of the disk. When a pair of magnetic heads is pressed against a magnetic disk by a magnetic head loading mechanism, if the head enters the disk at a high speed, the magnetic disk will be damaged by the impact at the time of collision. Therefore, it is necessary to control the entry speed as much as possible, and it has been experimentally found that a speed of about 10 cm/sec or less is preferable. However,
In the conventional loading mechanism using a linear solenoid, the solenoid's characteristic is that the speed gradually increases after the operation starts, so the speed when the head enters the disk is the highest, which prevents disk damage. It had the major drawback of being easy to occur. In addition, as a technique for preventing damage to the recording medium and the magnetic head, there is a technique such as that described in Japanese Patent Laid-Open No. 52-11913, in which the drive windings of the solenoid each generate torque in opposite directions. There is a damper that controls the balanced state of the drive torque by using a heavy winding and inserting a heat-sensitive element whose internal resistance changes with a time constant into one of the windings.

However, this technique slows down the overall loading speed, consumes unnecessary current, and increases heat generation. The present invention was made to overcome the drawbacks of the conventional loading mechanism as described above, and an object of the present invention is to smoothly operate a magnetic head when loading it onto a magnetic recording medium. In addition, it is an object of the present invention to provide a loading mechanism for a magnetic head in which the speed is controlled so that the head starts loading onto the disk relatively quickly and makes a soft landing when landing, thereby preventing damage.

In order to achieve the above object, a magnetic head loading mechanism according to the present invention drives a magnetic head assembly that supports a magnetic head by a rotary solenoid, and operates the solenoid in such a way that the current is shifted from a relatively small current to a large current. It is characterized by controlling the current. This allows the head loading time to be significantly reduced. Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 3 is a perspective view showing one embodiment of the invention, and FIGS. 4 and 5 are diagrams for explaining the operating state of the magnetic head loading mechanism according to the invention.

In these figures, 11 is a jacket, 12 is a flexible magnetic disk, 13 is a rotary electromagnetic drive means, 14 is a disc, 15 is a stopper pin, 16 is a recovery spring, 17 is a connecting member, and 18 is a support member. , 19 is a support shaft, 20 is a stopper groove, 21 is a pin, and 22 is a rotating shaft of the rotary electromagnetic drive means 13. See Figure 3. The flexible magnetic disk 12 housed in the jacket 11 is rotated at a certain rotation speed, for example, 360 rpm. p. m. The magnetic head 2 is mounted inside the carriage to magnetically write and read information. The carriage 4 is guided by two guide bars 8 extending over the magnetic disk 12, moves in the direction of the track on the surface of the magnetic disk 12, and is appropriately positioned. The magnetic head 2 operates while the carriage 4 is being guided by the guide bar 8 or when information is not being read or written to the magnetic disk 12 for a long time.
In order to avoid unnecessary wear on the magnetic disk 12 and the magnetic head 2, the magnetic head is lifted from the disk surface and placed in an unloaded state. It is only necessary to load the magnetic head onto the magnetic disk when the positioning of the carriage 4 with respect to the magnetic disk 12 is completed and the reading and writing of information to the disk 12 is started. FIG. 4a shows the magnetic head in the unloaded state. A front view of the head loading mechanism, FIG. 4b is a side view of the same (however, the connecting member 17, disk 14, etc. are omitted), and FIG. 5 is a front view of the magnetic head loading mechanism in the loading state. However, since the loading and unloading operating states are the same as those described above for the conventional loading mechanism with reference to FIGS. 1 and 2, further explanation will be omitted. Now, returning to FIG. 3, the loading and unloading operation mechanism will be explained.

Rotary electromagnetic drive means 13 attached to support member 18
When the disc 14, which is concentrically and directly connected to the rotating shaft 22, rotates by the drive of the rotary electromagnetic drive means 13, the pin 21 protruding from the disc 14 engages in a groove at one end of the connecting member 17, as shown in the figure. Because of this, the end of the connecting member 17 is connected to the support shaft 19.
The other end of the connecting member 17 moves up and down, but since this other end is engaged with the arm 3 of the magnetic head assembly 1, its up and down movement causes the magnetic head 2 to move up and down. Loading and unloading can be performed, but the loading and unloading operations in this area are no different from conventional ones. A stopper pin 15 embedded in the enclosing case of the rotary electromagnetic drive means 13 is interposed in the stopper groove 20 provided in the disc 14, and the stopper pin 15 is inserted into the stopper groove 20 provided in the disc 14. The positioning of each rotational position is performed. That is, in the mechanism described above, when the rotary electromagnetic drive means 13 is driven by energization, the rotation of the rotation shaft 22 causes the disc 14 to rotate within the rotation angle limited by the groove 20 and the stopper pin 15. rotate within the range and move the magnetic head assembly 1 to the carriage 4.
The magnetic head 2 mounted in the assembly 1 is loaded by closing the assembly 1 . After the disk 14 has been rotated by the rotational electromagnetic drive means 13, the return operation is performed by the action of a recovery spring 16 stretched between the pin 21 and any other fixed point. Comparing the conventional mechanism shown in FIG. 1 and the mechanism according to the present invention shown in FIG. Connecting member 17
Since the mechanism is such that the movement is converted into vertical movement by the groove engagement between one end of the pin 21 and the pin 21, it is clear that the power transmission is sufficiently smooth compared to that of a conventional linear solenoid.

Next, the reason why collision between the magnetic head 2 and the magnetic disk 12 during loading can be avoided by using the rotational drive by the rotary electromagnetic drive means 13 will be explained.

FIG. 6 shows a rotary electromagnetic drive means 13 used in this invention.
FIG. 7 is a longitudinal sectional view of a main part of an example of the device, and is a diagram for explaining the principle of operation thereof, and FIG. 7 is a diagram showing the torque characteristics of the same means.

In these figures, 22 is a rotating shaft, 23 is a stator,
24 is a coil, 25 is a rest position, 26 is a rotating member that is linked to the rotation of the rotating shaft 22, 27 is a start stopper, 28
indicates a tension spring. Please refer to FIG.

The operating principle of this rotary electromagnetic drive means is similar to that of a step motor. A coil 24 is attached to the rotating shaft 22 by appropriate means, and the rotating shaft 22 is supported at both ends by appropriate means (not shown) and is disposed in the stator 23 as shown. Now, when the coil 24 is energized, the coil 24 attracts the N and S poles in the stator 23 due to magnetization, so the rotating shaft 24 to which the coil 24 is attached
2 rotates, and the coil 24 reaches the position shown by the dotted line and remains stationary. The rotating member 26 that is interlocked with the rotating shaft 22 similarly reaches a resting position 25 and becomes stationary. When the current in the coil 24 is stopped, the magnetization of the coil 24 is stopped, so the rotating member 26
is restored by the tensile force of the tension spring 28 and stops when it hits the stopper 27. Thus, the rotating shaft 22 reciprocates between the position in contact with the stopper 27 and the rest position 25 depending on whether or not the coil 24 is energized. 7th
The figure shows the relationship between the rotation angle of the rotating shaft 22 and the torque.

The torque changes from the maximum value to zero by the time the rotating shaft 22 reaches the rest position 25, with the starting position being the position where the rotating member 26 interlocked therewith contacts the start stopper 27. This is exactly the opposite of the linear solenoid used in the prior art, where the movable member reaches its maximum speed at the position where it should come to rest after starting. Therefore,
When driven by such a rotary electromagnetic drive means, the torque can be made extremely small at the rotation end position of the rotary shaft 22 at which the disk 14 is to be rotated, as shown in FIG. If the amount of rotation of the rotary shaft 22 is selected to correspond to the completion of loading of the magnetic head onto the magnetic disk, damage caused by collision between the head and the disk can be prevented. In particular, in the present invention, by controlling the magnitude of the current supplied to the coil 24, the rotation of the rotating shaft 22 is controlled. Generated torque can be controlled.

For example, by gradually increasing the current shown in Fig. 8 and increasing the voltage, the torque suddenly decreases from a higher starting position shown in Fig. 7, thereby performing high-speed loading. It is something. Let me explain in detail. and,
In FIG. 3, a recovery spring 16 actuated via a pin 21 is attached to a disk 14 that is directly connected concentrically to a rotating shaft 22.
By controlling the current flowing through the coil 24, the position where the force and the load torque determined by the rotation angle of the disk 14 are exactly balanced and at rest can be arbitrarily determined. Therefore, it is clear that the rest position thus determined should be selected so as to correspond to the state in which the magnetic head has just completed loading onto the magnetic disk. FIG. 8 shows the relationship between the voltage waveform to be applied to the coil 24 and the acceleration of the magnetic head at that time, which is desirable for carrying out the present invention.

Note that the state at the moment when the magnetic head just loads onto the magnetic recording medium is sometimes called landing. As is clear from the above detailed explanation, according to the present invention, since the entry speed during magnetic head loading can be controlled with high precision, there is no damage to the magnetic recording medium during magnetic head loading. In addition, we have eliminated the conventional complicated and expensive link mechanism and adopted a simple, inexpensive, and highly reliable power transmission mechanism, creating an excellent magnetic head loading mechanism that can be installed in a much smaller space than before. Furthermore, the loading time of the magnetic head can be significantly shortened by current control.

[Brief explanation of drawings]

FIG. 1 shows a front view of a conventional magnetic head loading mechanism, and FIG. 2 shows a side view of the main parts thereof. FIG. 3 shows a perspective view of an embodiment of the invention, and FIGS. 4 and 5 show diagrams for explaining the operating state of the magnetic head loading mechanism according to the invention. FIG. 6 is a vertical cross-sectional view of a main part of an example of a rotary electromagnetic drive means used in the present invention, FIG. 7 is a diagram showing the torque characteristics of the same means, and FIG. FIG. 3 is a diagram showing an example of a voltage waveform and an acceleration waveform of a magnetic head. In the figure, 1
is a magnetic head assembly, 2 is a magnetic head, 3 is an arm, 4
is a carriage, 5 is a linear solenoid, 6 is a link, 7
is the recovery spring, r is the operating spring, 8 is the guide bar, 9
is a fulcrum of the link 6, 10 is a movable member, 11 is a jacket, 12 is a flexible magnetic disk, 13 is a rotary electromagnetic drive means, 14 is a disc, 15 is a stopper pin, 16 is a recovery spring, and 17 is a connection 18 is a support member, 19 is a support shaft, 20 is a stopper groove, 21 is a pin, 22 is a rotating shaft,
23 is a stator, 24 is a coil, 25 is a rest position, 26 is a rotating member, 27 is a start stopper, and 28 is a tension spring.

Claims (1)

[Claims] 1 A magnetic head loading mechanism that loads a magnetic head onto a continuously rotating disk-shaped recording medium, which includes a magnetic head assembly that supports the magnetic head, and a magnetic head assembly that engages with the magnetic head assembly and adjusts the torque from the maximum torque to the minimum torque. 1. A magnetic head loading mechanism comprising: a rotary solenoid that loads a magnetic head using a rotational driving force that transfers to a magnetic head; and a rotary solenoid that controls a drive current that drives the rotary solenoid.