JPH0510908B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a floppy disk drive device that uses a linear pulse motor to drive a magnetic head.

[Prior Art] In recent years, office automation (OA) has become popular, and floppy disk devices are widely used as storage devices. Linear pulse motors are often used to drive the heads of these floppy disk devices, and there is a strong demand for smaller, cheaper, and thinner motors. Therefore, the present applicant previously proposed a linear pulse motor that achieves the above requirements in Japanese Patent Application No. 59-47863.

3 and 4 are perspective views showing an example of the configuration of a linear pulse motor similar to the linear pulse motor according to the above proposal. In these figures, 1 is a mover made of mild steel or the like, 2 is a stator, and the lower surface of this mover 1 is formed with comb-shaped mover teeth 1a.

On the other hand, the stator 2 sequentially attracts the mover teeth 1a by sequentially switching magnetic poles with increasing magnetic flux through the interaction between the permanent magnet 3 and the electromagnet, thereby causing the mover 1 to reciprocate in a stepwise manner. , consists of the following structure.

First, on the lower side of the mover 1, opposite to this,
A slit plate 4 made of a metal plate is disposed, and a yoke 6 to which electromagnetic coils 5, 5 are fixed, and a permanent magnet 3 having an H-shape in plan view are sequentially fixed to the lower side of the slit plate 4. ing. A cross-shaped groove is formed in the center of the yoke 6, thereby forming four magnetic poles 6a, 6b, 6c, and 6d.
It also has legs 6e, 6f, 6g, and 6h extending outward. In addition, magnetic poles 6a, 6b, 6c, 6d
Comb-shaped pole teeth 4a, 4b, 4c, and 4d are formed on the slit plate 4 at a position directly above the slider 1, and face the slider teeth 1a of the slider 1 with a very small gap therebetween. , further leg portions 6e, 6f, 6
Legs 4e, 4f, 4g, so as to overlap with g, 6h,
4h is formed.

Each pole tooth 4a, 4b, 4c, 4d and mover tooth 1a
The gap between is formed by a pair of linear bearings 7, 7 arranged on both sides of the slit plate 4, and the slider 1 is placed on the linear bearing 7.
is mounted, and the linear bearing 7 and the slider 1 are fitted so as to be movable in the longitudinal direction along the guide path formed by the slit plate 4 and the guides 8, 8. In this case, the guides 8, 8 are made of plastic, and the guides 8, 8, the slit plate 4, the yoke 6, and the coils 5, 5 are screws 10,
10... are connected to each other and are integrated.

FIG. 5 is a perspective view showing the configuration of the linear bearing 7. As shown in the figure, the linear bearing 7 includes a pair of rollers 11, 11, balls 12,
12 and a retainer 13 that holds them.The rollers 11, 11 are connected to the openings 14, 14.
The balls 12, 12 are rotatably fitted into the recesses 15, 15, respectively. In FIG. 4, 16 is a stopper that is bent upward to restrict movement of the linear bearing 7, and 18 is a back plate for forming a magnetic path for the permanent magnet 3.

According to the above configuration, both sides of the lower surface of the slider 1 come into contact with the rollers 11, 11 of the linear bearing 7,
Further, both side edges of the mover 1 abut against the balls 12, 12. Then, the movable tooth 1a and the pole teeth 4a, 4
b, 4c, and 4d face each other with a slight gap in between. In this state, when a predetermined pulsed current is supplied to the coils 5, 5, the mover 1 moves stepwise and linearly on the stator 2.

[Problems to be Solved by the Invention] By the way, when the above-mentioned linear pulse motor is used as a head feeding motor for a floppy disk device, the magnetic head that writes and reads data to and from the magnetic disk must be The magnetic disk is directly moved in the radial direction by the mover 1, but in this case, the linear pulse motor is required to have high positioning accuracy. However, in the above-described linear pulse motor, the guides 8, 8 that define the moving direction of the slider 1 are made of plastic, while the slit plate 4 and yoke 6 to which the guide 88 is attached are made of metal. Because it has been
Due to these differences in thermal expansion coefficients, the relative positional relationship of the guides 8, 8 with respect to the slit plate 4 and the yoke 6 will shift as the outer peripheral temperature changes, and the direction of movement of the slider 1 will change. There is a risk of deviation from the normal direction of movement. Therefore, there was a risk that the positioning accuracy of the linear pulse motor would deteriorate due to a change in the outer peripheral temperature. Furthermore, for example, when the outer peripheral temperature changes, if the direction of elongation due to thermal expansion of the magnetic disk and the direction of elongation due to thermal expansion of the guides 8, 8 become opposite, the positioning error of the magnetic head increases. Resulting in.

This invention was made in view of the above-mentioned circumstances, and aims to prevent a decrease in positioning accuracy caused by a change in the outer circumferential temperature.

[Means for Solving the Problems] The floppy disk drive device of the present invention is provided with a linear pulse motor that moves the head along the radial direction of the magnetic disk at a position outside the radius of the magnetic disk. A linear pulse motor has a plate-shaped magnetic pole component having a magnetic pole formed in the center and four legs extending outward, which are arranged parallel to each other, and both ends are attached to each of the legs. and a slider provided movably along a guide path along the radial direction of the magnetic disk by the pair of guide members, and each of the pair of guide members Grooves are formed on each surface of the one end and the leg that abut each other, and the surfaces on which the grooves are formed are adhered to each other with synthetic resin, and the one end on the adhesive side is attached to a magnetic disk. It is characterized by being placed towards the

[Function] The floppy disk drive device of the present invention uses a pair of guide members to form a guide path along the radial direction of the magnetic disk, and one end of each of the guide paths is fixed to the magnetic pole component. The direction of expansion and contraction of the guide member due to temperature changes always matches the direction of movement of the slider, and only one end of the guide member is fixed, with the fixed end facing the magnetic disk. Therefore, the thermal expansion and contraction of the floppy disk and the thermal expansion and contraction of the guide member can be canceled out, and the relative positional shift of the magnetic head can be canceled out by the simultaneous thermal expansion and contraction of the guide member.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1a is a plan view showing an embodiment of the floppy disk drive apparatus of the present invention, and FIG. 1b is a perspective view of a linear pulse motor applied to the floppy disk drive of FIG. 1a. As shown in this figure, the slit plate 4 at one end of each guide 8,8
Grooves 8a, 8a, . . . extending in a direction perpendicular to the direction of movement of the mover 1 are formed on the surfaces that come into contact with the mover 1, respectively. On the other hand, the legs 4g and 4h of the slit plate 4
Grooves 4i, 4i, . . . extending in a direction perpendicular to the direction of movement of the slider 1 are formed by half-etching on the surfaces that contact one end of each of the guides 8, 8, respectively. Then, the guides 8, 8 having such a configuration are connected to the screw 1 as in the conventional example shown in FIG.
When attaching the guide 8 and the slit plate 4 onto the slit plate 4 by means of 0, 10, etc., as shown in FIG. After the resin 20 is allowed to harden within each of the grooves 8a, 8a, . . . and 4i, 4i, . . ., it is fixed with screws 10, 10, .

According to the above configuration, one end of each of the guides 8, 8 is tightly fixed to each leg 4g, 4h of the slit plate 4, so that the direction of expansion and contraction of the guides 8, 8 when the outer temperature changes is As shown in FIG. 1a, this linear pulse motor is placed at a position radially outward of the magnetic disk 30 of the floppy disk drive, and the guides 8, 8 Magnetic disk 3 in the direction of expansion and contraction
A magnetic head 31 is attached to the tip of the slider 1, with one end of the slit plate 4 on the side closely fixed to the legs 4g, 4h facing the magnetic disk 30.

With this configuration, it is possible to prevent relative displacement between the magnetic disk 30 and the magnetic head 31 due to changes in the outer peripheral temperature.

In other words, the linear pulse motor has its moving element 1
Since the moving direction (longitudinal direction of the guides 8, 8) is arranged to be the radial direction of the magnetic disk 30, the expanding/contracting direction (radial direction) of the magnetic disk 30 matches the expanding/contracting direction of the guides 8, 8. It turns out. Further, during thermal expansion, the magnetic disk 30 extends radially outward by, for example, ΔL ₁ , whereas the guides 8, 8 of the linear pulse motor also extend outside the radius of the magnetic disk 30 around the fixed point at the one end. Since both are made of plastic, ΔL ₁ ≒ΔL ₂ can be established, and therefore, the position of the magnetic head 31 due to thermal expansion and contraction of the magnetic disk ₃₀ The misalignment can be canceled out by simultaneous thermal expansion and contraction of the guides 8, 8 (guiding members).

"Effects of the Invention" As explained above, according to the floppy disk drive device of the present invention, the relative positional shift of the magnetic head due to thermal expansion and contraction of the magnetic disk can be canceled out by the simultaneous thermal expansion and contraction of the guide member. Therefore, even if the outer peripheral temperature changes, the positioning accuracy of the magnetic head can be maintained at a high level.

[Brief explanation of drawings]

FIG. 1a is a plan view showing an embodiment of the floppy disk drive device of the present invention, FIG. 1b is an exploded perspective view of a linear pulse motor used in the floppy disk drive, and FIG. 2 is the same. 3 is a perspective view showing the structure of a conventional linear pulse motor, FIG. 4 is an exploded perspective view showing the structure of the linear pulse motor, and FIG. 5 is a perspective view showing the structure of the conventional linear pulse motor. FIG. 2 is a perspective view showing the configuration of a linear bearing of a pulse motor. 1...Mover, 4...Slit plate, 4a, 4
b, 4c, 4d...pole teeth, 4e, 4f, 4g, 4
h... Leg portion, 4i, 4i... Groove portion, 6... Yoke, 8... Guide (guiding member), 8a... Groove portion,
20...Synthetic resin.

Claims (1)

[Claims] 1. A linear pulse motor that moves the head along the radial direction of the magnetic disk is provided at a position radially outward of the magnetic disk, and the linear pulse motor has a magnetic pole formed in the center and extends outward. A plate-shaped magnetic pole component having four legs, a pair of guide members arranged parallel to each other and having both ends attached to each of the legs, and the pair of guide members to guide the magnetic disk. a slider provided so as to be movable along a guide path along a radial direction, and a groove portion is formed in each surface of each end portion of the pair of guide members and the leg portion that abut each other, A floppy disk drive device characterized in that the surfaces on which the grooves are formed are bonded to each other with synthetic resin, and one end of the bonded side is disposed facing the magnetic disk.