JPH076943U - Disk holding mechanism - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention relates to an improvement of a disk holding mechanism having a center hub for holding a disk and a chucking magnet for attracting the disk on opposite surfaces. [Structure] A disk holding member made of a bowl-shaped magnetic member on which a center hub made of a magnetic member is placed, and a disk holding mechanism made of a magnet held in the bowl-shaped recess facing the center hub. Therefore, the attraction force between the magnet and the disc holder is set to be larger than the attraction force between the magnet and the center hub.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to the structure of a motor device for driving a recording / reproducing disk such as a magnetic disk or an optical disk. More specifically, the present invention relates to a center hub for holding the disk and a chucking magnet for adsorbing the center hub. The present invention relates to a disc holding mechanism having a pair of opposed surfaces.

[0002]

[Prior art]

 FIG. 4 shows a conventional example of a holding mechanism of a spindle motor disk for a magnetic disk, to which members related to the invention are applied. The disc holding mechanism 1 holds a disc 8 having an open central portion, and is formed in a dish shape so that a center hub 4 made of a magnetic material locks the disc peripheral edge surface and the outer peripheral surface of the spindle 7. There is a holding body 2 which is formed in a bowl shape and has an annular rib so as to face downward. The holder 2 is a hub in which the inner peripheral surface 22 of the rib engages with the outer peripheral surface 41 of the center hub 4, and the annular edge portion 23 of the rib contacts the disk 8 to form a disk table. An annular magnet 3 for sucking the center hub 4 is in contact with the inner bottom surface 26 of the holder 2 at the bottom surface 31 of the bowl-shaped recess 24 of the holder 2 and is joined with an adhesive or the like. .

The central portion of the holding body 2 is fixed to a spindle 7 which rotates with the rotation of a rotor (not shown), the disc 8 is placed on a disc table, and the central opening hole 42 of the center hub 4 is inserted into the spindle 7. When it is inserted into the outer peripheral surface, the outer peripheral surface 41 of the center hub 4 and the inner peripheral surface 22 of the rib are engaged with each other, and at the same time, the center hub 4 is attracted by the magnetic force of the magnet 3.

Since the disk 8 is sandwiched between the disk table and the outer peripheral surface 43 of the center hub, the rotation of the spindle 7 causes the holder 2 and the center hub 4 to rotate. It is possible to rotate without moving the recording surface of the surface in the peripheral direction.

When the amount of adhesive applied to the inner bottom surface 26 of the holding body 2 and the bottom surface 31 of the magnet 3 is small, or when the adhesive is deteriorated due to long-term use, the center hub 4 is originally operated by the magnet 3. While the magnet 3 is attracted toward the holder 2, the magnet 3 is attracted toward the center hub 4, and the magnet may peel off from the inner bottom surface 26 of the holder 2 and fall off.

When the magnet holding force of the holding body 2 is weaker than the magnet holding force of the center hub 4, the magnet 3 is attracted to the center hub 4 by the magnetic force, and the magnet is removed from the inner bottom surface 26 of the holding body 2. There was a risk of peeling and falling.

[0007]

[Problems to be solved by the device]

 As explained in the conventional example, when the amount of adhesive applied to the inner bottom surface of the holder and the bottom surface of the magnet is small, or when the adhesive deteriorates due to long-term use, and the magnet holding force of the holder is centered. If the magnet holding force is weaker than that of the hub, the magnet may be attracted toward the center-hub, and the magnet may peel off from the inner bottom surface of the holder and fall off to cause the disk holding mechanism to fail.

In view of this, the present invention proposes that the amount of adhesive applied to the inner bottom surface of the holder and the bottom surface of the magnet is small, or the adhesive has deteriorated due to long-term use, and the magnet holding force has a magnet holding force of the center hub. In order to solve the problem that the magnet is attracted toward the center hub when it is weaker than the force, and the magnet peels off from the inner bottom surface of the holder and falls off, the structure of the magnet and the holder forming the disk holding mechanism is changed. That is the summary.

[0009]

[Means for Solving the Problems]

 In view of this, the present invention proposes a disk holder made of a bowl-shaped magnetic body on which a center hub made of a magnetic body is mounted, which is fixed to the spindle, and the bowl-shaped recessed portion facing the center hub. In a disk holding mechanism including a magnet held by the magnet, the attraction force between the magnet and the disk holder is made larger than the attraction force between the magnet and the center hub.

As a means therefor, the magnet is composed of a bottom having a wide surface and an upper portion having a narrow surface, and the bottom is held in the bowl-shaped recess of the holder to hold the magnet and the disk. The attraction force between the magnet and the center hub is made larger than the attraction force between the magnet and the center hub, and further, the thickness of the bowl-shaped recess of the disc holding body is set to the magnet and the disc. The thickness is such that the attractive force between the holding body and the magnet is greater than the attractive force between the magnet and the center hub.

[0011]

[Action]

 The shape of the annularly formed magnet 3 for sucking the center hub in the bowl-shaped recess of the holding body is such that the bottom surface area is larger than the top surface area, for example, a frustoconical shape. If the bottom surface is joined to the inner bottom surface of the holding body with an adhesive or the like, the contact surface becomes wider, so that the suction force increases and the suction force with the holding body becomes larger than the suction force of the center hub.

Further, the thickness of the bowl-shaped recess of the holder is increased so that the attraction between the magnet and the disc holder is larger than the attraction between the magnet and the center hub. To do.

[0013]

【Example】

 The same reference numerals are attached to those having the same function as the conventional example.

FIG. 1 shows an embodiment of the present invention. In the figure, a center hub 4 formed of a magnetic material for holding a disk 8 having an open central portion is formed in a dish shape so as to engage the peripheral edge surface of the disk and the outer peripheral surface of the spindle 7. There is a holding body 2 which is formed in a bowl shape and has annular ribs facing each other in the downward direction.

The holder 2 may be formed of a magnetic material alone. Alternatively, as shown in FIG. 2, the bottom portion 27 and the rib may be molded with a non-magnetic material such as aluminum to form a hub. A magnetic material may be fixed to the bottom of the recess 24 to form the yoke 6, and then the magnet 3 may be attached.

The holding body 2 is a hub in which the inner peripheral surface 22 of the rib engages with the outer peripheral surface 41 of the center hub 4, and the annular edge 23 of the rib contacts the disk 8 to form a disk table. There is. An annular magnet 3 for attracting the center hub 4 is brought into contact with the inner bottom surface 26 of the holder 2 at the bottom surface 31 of the bowl-shaped recess 24 of the holder 2 and is bonded thereto with an adhesive or the like.

The center of the holder 2 is fixed to a spindle 7 which rotates with the rotation of a rotor (not shown), the disk 8 is placed on a disk table, and the central opening hole 42 of the center hub 4 is inserted into the spindle 7. When it is inserted into the outer peripheral surface, the outer peripheral surface 41 of the center hub 4 and the inner peripheral surface 22 of the rib are engaged with each other, and at the same time, the center hub 4 is attracted by the magnetic force of the magnet 3.

Since the disk 8 is held between the disk table and the outer peripheral edge surface 43 of the center hub, the rotation of the spindle 7 causes the holder 2 and the center hub 4 to rotate, and the disk 8 accordingly moves. It is possible to rotate without moving the recording surface of the surface in the peripheral direction.

FIG. 3 is a view showing a side surface shape of a truncated cone when the magnet 3 is formed into a substantially truncated cone in order to change the attraction force of the magnet 3 between the upper surface and the bottom surface. In addition to a straight line, the side surface of the truncated cone has various shapes such that the bottom surface 31 is wider than the top surface 30 such as a figure (a) arc 35, a figure (b) parabola 36, a figure (c) and a figure (d) staircase shape 37. You can

As a result, the magnetic force of the bottom surface 31 of the magnet 3 is always higher than that of the upper surface 30, so that the attraction force between the magnet 3 and the holding body 2 is greater than the attraction force between the magnet 3 and the center hub 4.

In addition, the thickness b of the yoke 6 made of a magnetic material of the inner bottom portion 26 of the bowl-shaped recess 24 forming the holding body 2 shown in FIG. The thickness may be larger than the attraction force between the magnet and the center hub.

In the embodiment, the member forming the center hub 4 and the member forming the yoke 6 are made of the same material, but different members may be used as long as they are magnetic bodies. In this case, since the magnetic permeability changes, the thicknesses of a and b can be changed so that the holding force of the holding body 2 is larger than that of the center hub 4.

As shown in FIG. 3, the shape of the magnet 3 is made wider at the bottom surface 31 than at the top surface 30 so that the attraction force of the holding body 2 is increased by the attraction force between the magnet 3 and the disk holding body 2. The problem can be solved by using each of the methods of making the thickness so as to be larger than the attraction force between the center 3 and the center hub 4 alone or in combination.

In addition to the embodiment, the present invention is such that a chucking magnet for holding a disc is attached to a holding body 2 at least a part of which is made of a magnetic material, and a center hub for holding the disc is provided facing the magnet. Applies to all of the disk retention mechanisms that are present. Therefore, other than the embodiments described above, various modifications can be made without departing from the scope of the present invention.

[0025]

[Effect of device]

 The attraction force between the shape of the magnet and the disc holder is made larger than the attraction force between the magnet and the center hub, so that the attraction force between the magnet and the disc hub is greater than the attraction force between the magnet and the disc hub. Since the adsorption power is increased, the force that presses the adhesive applied to the bottom surface of the magnet is applied, the adhesive is less likely to peel off, not only does the reliability of the adhesive increase, but the adhesive serves as an auxiliary means or can be omitted. Therefore, the economic value is high.

[Brief description of drawings]

FIG. 1 is an embodiment of the present invention.

FIG. 2 is another embodiment of the present invention.

FIG. 3 is a view showing a side surface shape of a truncated cone when the magnet has a substantially truncated cone shape because the attraction force of the magnet changes between the top surface and the bottom surface.

FIG. 4 is a conventional example of a device relating to the invention.

[Explanation of symbols]

 2 holding body 3 magnet 4 center-hub 6 yoke 7 spindle 8 disk 22 rib inner peripheral surface 23 rib annular edge 24 bowl-shaped recess 26 inner bottom surface 27 bottom 30 upper surface 31 bottom surface 35 arc 36 parabola 37 staircase shape 41 outer peripheral surface 42 central opening hole 43 outer peripheral surface.

Claims (3)

[Scope of utility model registration request] 1. A disk holder made of a bowl-shaped magnetic body on which a center hub made of a magnetic body is mounted, which is fixed to a spindle, and a center of the disk, and the bowl-shaped holder so as to face the center hub. In a disk holding mechanism including a magnet held in a recess, an attraction force between the magnet and the disk holder is made larger than an attraction force between the magnet and the center hub. Disk holding mechanism. 2. The disc holder according to claim 1, wherein the magnet has a bottom having a wide surface and an upper surface having a narrow surface, and the bottom is held in the bowl-shaped recess of the holder. mechanism. 3. The thickness of the bowl-shaped recess of the holder is such that the attraction between the magnet and the disk holder is greater than the attraction between the magnet and the center hub. 3. The disk holding mechanism according to claim 1 or 2, wherein the disk holding mechanism has a thickness of