JPH07334900A - Disk driving device - Google Patents

Abstract

PURPOSE:To prevent disk from floating up from a rotationally driven rotary body by forming the abutted part of a driving pin abutting on the positioning hole of a metallic hub into an inclined surface. CONSTITUTION:One end part of a turning arm 5 arranged on the lower surface side of a disk-like part 4b of the rotationally driven rotary body 4 is turnably mounted on the disk-like part 4b through a supporting shaft 8, and the driving pin 6 is arranged in another end part. The driving pin 6 is projected upward so as to be capable of retaining the positioning hole 2b of the metallic hub 2 of the disk 1 through a hole 4c formed on a disk-like part 4a. This driving pin 6 is made into the shape of an inverse truncated cone, the diameters of which is made larger, as going from the lower part 6b to the upper part 6a, and set on the inclined surface with an inclined angle smaller than 90 deg. to the horizontal surface at the position abutting on the metallic hub 2. By this arrangement, the metallic hub of the disk is always positioned accurately on the rotary body 3, and the generation of burst deviation or trucking error is prevented since the floating of the head or the eccentricity does not occur.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive device for rotationally driving a disk-shaped recording medium such as a 3.5 inch floppy disk.

[0002]

2. Description of the Related Art Generally, as shown in FIGS. 3 and 4, a disk drive device of this type has a disk-shaped recording medium (hereinafter referred to as a disk) 1 on a rotating body 4 which is a turntable integrated with a rotating shaft 3. The rotary shaft 3 is inserted into the chucking hole 2a of the metallic hub 2 made of a ferromagnetic material by being mounted on the rotary shaft 3. The drive pin 6 on the arm 5 attached to the lower side of the rotating body 4 is projected from the lower surface side of the rotating body 4 to the upper surface side, and inside the positioning hole 2b of the metal hub 2 at a position deviated from the chucking hole 2a. The metal hub 2 is held by being attracted by the magnet 7 on the rotating body 4 while being inserted into the. The drive pin 6 has a cylindrical shape and abuts the metal hub 2 at a right angle. When the rotary body 4 current is injected into the motor of the lower (not shown) is rotated, the contact portion 2b ₁ of the metallic hub 2 by the rotational force R and disk load drive pin 6 and the driving pin 6, 2b ₂ Of the rotating shaft 3 and the chucking hole 2a by the force P1 acting in the radial direction and the force P2 acting in the rotating direction at
The disk 1 is rotationally driven by being brought into contact with the rotary shaft 3 and positioned at two positions a ₁ and 2a ₂ . When the disk 1 rotates, the metal hub 2 is brought into close contact with the rotating body 4 with no gap.

[0003]

By the way, in this type of device, the metallic hub 2 may float above the rotating body 4 as shown in FIG. Details of the drive pin 6 and the contact portions 2b ₁ and 2b ₂ of the positioning hole 2b at this time are enlarged and shown in FIG.

3 and 6, the force P acting on the metallic hub 2 by the rotational force of the drive pin 6 and the load of the disk 1
As a reaction of 1 and P2, the driving pin 6 is naturally P1 and P2.
Force that acts. On the other hand, the floating metal hub 2 has a force F that returns in the arrow direction due to the attraction force of the magnet 7 for attraction, and this force and the frictional force of P1 and P2 at the contact portions 2b ₁ and 2b ₂ cause the metal hub 2 to move. The hub 2 has a force f ₁ that adheres to the surface of the rotating body 4 and a force f ₂ that impedes it.
Exists.

That is, f ₁ = F + (P 1 + P ₂ ) sin θ f ₂ = μ × (P 1 + P 2) cos θ. Note that μ is the friction coefficient at the contact portion, and θ is the inclination angle of the disc 1.

Here, considering the parameters of the above equation, the following values are obtained. θ (tilt angle) ≦ 3 °, F = 10 to 15 g, μ = 0.2 to
0.3, P1 ≤ 25g, P2 ≤ 50g, substituting the above values into the above formula, f ₁ = (10-15) + (25 + 50) sin 3 ° = 1
3 to 15 (g) f ₂ = (0.2 to 0.3) × (25 + 50) cos 3 °
= 15 to 22 (g), and when f ₁ > f ₂ , the metal hub 2 can be attracted to the rotating body 4 and maintain a horizontal state, but f ₁ ≦ f ₂
At this time, the metal hub 2 remains inclined with respect to the upper surface of the rotating body 4. Therefore, when the metal hub 2 remains tilted, the head floats or is eccentric with respect to the disk 1 at the contact portion 2b ₁ and the trace does not become a perfect circle, resulting in off-track, and the contact portion 2b ₂ rotates at the contact portion 2b _2. The problem arises that the directional positioning is misaligned.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and includes a rotating shaft fitted in a chucking hole provided in a central portion of a metal hub of a disk-shaped recording medium, and The rotary body is fixed to the rotary shaft to mount the disk-shaped recording medium, and the rotary body is rotatably supported by the rotary body and is fitted into the positioning hole arranged at a position deviated from the chucking hole. In a disk drive device including a rotating arm having a drive pin, the disk-shaped recording medium on the rotating body that is rotationally driven at an abutting portion of the drive pin that abuts a positioning hole of the metal hub. The present invention provides a disk drive device characterized in that it has an inclined surface so as to regulate the position.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a disk drive device according to the present invention will be described in detail below with reference to FIGS.

For the sake of convenience of explanation, the same reference numerals will be given to the same constituent members as those shown above.

The rotary body 4 serving as a turntable is formed into a bowl shape by press molding or the like, and the central portion of the disc portion 4a is projected so that the disc portion 4a and the metal hub 2 of the disc 1 can be mounted. And a protruding portion 4b. The rotary body 4 is supported by a bearing 9 of a motor unit (not shown) arranged in the lower portion and is rotated in a predetermined direction by fixing the rotary shaft 3 to the center of the protrusion 4b by press fitting or the like. A motor substrate 10 has a yoke and a coil fixed thereto. Further, a drive magnet facing the above coil is attached to the outer shape side (not shown) of the rotating body 4.

The rotating arm 5 arranged on the lower surface side of the disc portion 4b has one end rotatably attached to the supporting shaft 8 on the disc portion 4b and the other end portion of the present invention. A drive pin 6 forming a part of the section is arranged. The drive pin 6 projects upward so as to lock the positioning hole 2b of the metal hub 2 through the through hole 4c formed in the disc portion 4a.
An annular magnet 7 that magnetically attracts the metal hub 2 is fixed on the disc portion 4a.

In the present embodiment, the drive pin 6 and the rotary arm 5 are integrally formed of synthetic resin or the like to provide the rotary arm 5 with an elastic action. You may use what formed the arm 5 separately.

The drive pin 6 has a so-called inverted truncated cone shape whose diameter increases from the lower portion 6b to the upper portion 6a, and the inclination angle θ of the disk 1 with respect to the horizontal plane at the contact portion with the metal hub 2 is large. ₂ as shown in Fig. 2 90 °> θ
Set to be _2.

By setting the inclination angle of the drive pin 6 in this way, f ₁ in FIG.
Suppose that f ₂ is obtained. It should be noted that θ is an inclination angle of the disc 1 with respect to the rotating body 4. Where θ ₁ = θ + 90 ° −θ
_If it is set to ₂ , from the relation of f ₁ = F + (P 1 + P ₂ ) sin θ ₁ f ₂ = μ × (P 1 + P 2) cos θ ₁ , at θ ₂ = 90 °, it becomes the same as the conventional one.
Sin θ ₁ increases as 90 °> θ ₂ and cos
Since θ ₁ decreases, f ₁ > f ₂ , and the metal hub 2 is horizontally adsorbed on the rotating body 4 to eliminate the drawbacks of the prior art. Even when the metal hub 2 is in the horizontal state, (P1 + P2) sin θ ₁ of the above formula of f ₁ always acts, so that the rotor 4 is moved downward by magnetic attraction between the core and the drive magnet as in this embodiment. In the case of a motor that is pressed and rotated, if the downward pressing force of the rotating body 4 is 50 g or less, there is a problem that the rotor floats due to vibration during operation. Since the attraction force of this type of attraction magnet is about 90 to 120 g, it must be (P1 + P2) sin θ ₁ <40. As described above, P1 ≤25 g and P2 ≤50 g, and therefore θ ₁ <32.2 ° θ ₁ = θ + 90 ° -θ ₂ and therefore θ + 90 ° -θ ₂ <32.2 ° θ ₂ > 90 ° -32 2 ° + θ (since θ ≦ 3 °) θ ₂ > 60.8 °. Therefore, the inclination angle θ ₂ of the drive pin 6 is preferably in the range of 62 ° <θ ₂ <90 °.

In this way, by setting the angle of the inclined surface of the drive pin 6 so that f ₁ > f ₂ , the disk 1 which is mounted on the rotating rotor 4 by suction is driven by the drive pin 6. When driven to rotate, the inclined surface of the drive pin 6 and the contact portions 2b ₁ and 2b _{2 of the} positioning hole 2b cause the drive pin 6 to slightly move up or hit by the elastic force of the rotating arm due to the action of the inclined surface. By restricting the inclination of the metal hub 2 due to the levitation at the contact position, the metal hub 2 can stably maintain a horizontal state on the rotating body 4. That is, the off-track due to the floating of the head with respect to the disk 1 can be avoided at the contact part 2b ₁ , and the positioning in the rotational direction is accurately performed at the part of the contact part 2b _{2 so} that the reliability of the device is improved. .

[0016]

According to the disk drive apparatus according to the present invention described in detail above, since the metal hub of the disk is always accurately positioned on the rotating body and the head is not lifted or eccentric, burst displacement or tracking error occurs. Since it does not occur, it has a great effect on a disk drive device that requires high-density recording / reproduction.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a disk drive device of the present invention.

FIG. 2 is an enlarged view showing the relationship between the drive pin and the metal hub of the present invention.

FIG. 3 is an explanatory diagram showing a relationship between a metal hub and a drive pin.

FIG. 4 is a sectional view showing a conventional disk drive device.

5 is a cross-sectional view showing a floating state of the metal hub in FIG.

FIG. 6 is an enlarged view showing a relationship between a metal hub and a drive pin.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Disc-shaped recording medium, 2 ... Metal hub, 2b ... Positioning hole, 3 ... Rotating shaft, 4 ... Rotating body, 5 ... Rotating arm, 6
… Drive pin.

Claims (1)

[Claims] 1. A rotating shaft fitted into a chucking hole provided at the center of a metal hub of a disk-shaped recording medium, and a rotating body fixed to the rotating shaft for mounting the disk-shaped recording medium. And a rotating arm that is rotatably supported by the rotating body and has a drive pin that fits into a positioning hole that is located at a position offset from the chucking hole. A disk drive device, wherein an abutting portion of the drive pin that abuts a positioning hole of a hub made of an inclined surface is an inclined surface so as to regulate the position of the disk-shaped recording medium on the rotating body that is rotationally driven.