JPH11191255A - Disk clamping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the disk clamping device performing a balancing correction when the revolving speed of a clamp main body becomes a prescribed dangerous speed or higher in the case imbalance of weight exists in a disk. SOLUTION: This device is provided with the ring shaped balancing weight 25 provided slidably with respect to a clamp main body 10, plural tension spring members 27 for making pull strength act toward the revolving center side of the clamp main body 10 with respect to this balancing weight 25 and a leaf spring member 28 at whose top end pressing weights 30 which are to be in contact with the balancing weight 25 are provided and also whose base end is connected to the revolving center of the clamp maim body 10 and which urges the balancing weight 25 toward the clamp main body 10 side with prescribed repulsive forces and this device is constituted so that pressing weights 30 are separated from the balancing weight 25 against urging forces of the leaf spring member 28 by a centrifugal force when the revolving speed of the clamp main body 10 becomes the prescribed speed or higher. Thus, this device performs the balancing correction when the revolution of the clamp main body 10 becomes the prescribed dangerous speed of higher in the case imbalance of weight exists in the disk.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CD (Compa)
ct Disc) and DVD (Digital Vers)
The present invention relates to a disk clamp device attached to a disk device that records or reproduces information on a disk such as an atile disc), and more particularly to a disk clamp device having an unbalance correction function.

[0002]

2. Description of the Related Art Conventionally, as an apparatus for automatically correcting imbalance of a rotating body, there have been known many auto balancers for performing correction using a liquid or a ball. One example of these auto balancers is disclosed in Japanese Utility Model Laid-Open No. Sho 62-158172,
JP-A-59-183846, JP-A-2-1196
No. 94, JP-A-2-279198 and the like. As an example of this auto balancer, for example, if the ball is sealed in the balancer and the rotation speed of the rotating body becomes higher than the critical speed, the balancer will be in the opposite phase to the position of the unbalance of the rotating body and correct the imbalance It was to do. There has also been a technique in which a liquid is sealed in place of the above-described ball, and imbalance is corrected based on the same principle. Further, there is a combination of both a ball and a liquid. For example, the one shown in FIG. 11 is disclosed in JP-A-59-183846, and the balancer mechanism will be described below. However, the present invention relates to a balancer for a centrifugal rotating machine, and a washing machine is taken as an application example.

[0003] An annular chamber 111 provided at an upper peripheral portion of a rotary tub 110 for washing is partitioned by partition walls 116 provided at appropriate intervals in a vertical direction. However, a flow path 115 is provided in the partition below the annular chamber 111 so that the ball 112 and the liquid W can move between spaces separated by the partition. The outer peripheral wall 114 of the annular chamber 111 has a lower part located closer to the inner peripheral side than the upper part, and an upper peripheral wall and a lower peripheral wall are connected by an inclined surface 114a. The lower outer wall below the inclined surface 114a has a slope 114 that is steeper than the inclined surface 114a.
b. A plurality of the balls 112 are provided,
It can move in the circumferential direction of the rotary tank 110 together with the liquid W via the flow passage 115.

When the rotation of the rotary tank 110 is started, the liquid W
Tends to converge on the opposite side of the eccentricity. Ball 11
2 moves through the flow passage 115 to a position opposite to the eccentricity so that the liquid 2 flows through the liquid W. When the number of revolutions further increases, the ball 112 becomes inclined 11 due to centrifugal force.
4b and 114a. Further, the liquid W also has a vertical plane parallel to the upper outer peripheral wall 114 due to the centrifugal force, that is, a form like a dashed line. Even if the liquid W is in such a form, it will not be able to move in the circumferential direction because it is sandwiched by the partition 116 this time. Therefore, in this method, the balancer operates from a state where the number of rotations is low to a state where it is high.

[0005]

However, the balancer mechanism described above records information on a disk,
Alternatively, when the present invention is applied to a disk device from which information is read, there are the following problems. First, since a liquid is used for a part of the balancer, it is necessary to take measures against leakage of the liquid, which complicates the structure. In addition, since the liquid and the ball are used in combination, the cost of materials is increased as a whole, and the size of the balancer cannot be reduced.
Further, it is difficult to evenly distribute the ball once gathered in one place. In addition, there is also a problem that it is quite difficult to accurately fill a predetermined amount of liquid in the inside. The present invention focuses on the problems as described above, and has been conceived in order to effectively solve the problems. The purpose of the present invention is to perform rotation at a predetermined critical speed when there is a weight imbalance in a disk. It is an object of the present invention to provide a disk clamp device that performs balance correction when the number of data exceeds the number.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a disk clamping device for magnetically clamping a disk placed on a turntable, wherein the disk clamp can be attracted to the turntable by magnetic force. , A ring-shaped balance weight slidably provided with respect to the clamp body, and a plurality of pulls for applying a pulling force to the balance weight toward the center of rotation of the clamp body. A plate for providing a spring member and a holding weight at the distal end in contact with the balance weight, and a base end connected to the rotation center side of the clamp body to bias the balance weight toward the clamp body with a predetermined elastic force. A spring member, and when the clamp body has a predetermined rotation speed or more, the holding weight is moved by the plate Against the biasing force of the member is obtained by construction away from the balance weight.

Accordingly, when the disk is at a predetermined rotational speed or less, the balance weight is urged downward by the elastic force of the leaf spring member, so that the disk is in a so-called locked state. When the rotation speed exceeds
The centrifugal force applied to the holding weight attached to the distal end of the leaf spring member becomes greater than the urging force of the leaf spring member pressing the balance weight, and the holding weight rises slightly. As a result, the lock of the balance weight is released, and the balance weight becomes an open state in which the balance weight can be slid. Here, when the rotating disk has a weight imbalance and the center of gravity is deviated, the annular balance weight resists the pulling force of the tension spring member pulling it toward the rotation center. Then, the slider is slid in the direction opposite to the direction of the eccentricity by an amount for correcting the unbalance amount, whereby the entire rotating body is balanced.

Here, at the center of the clamp body, there is provided a sliding shaft slidable along the center of rotation, and at the base end of the sliding shaft, the clamp body is moved toward the turntable. An attracting magnet for attracting is provided, and a base end of the leaf spring member is fixed to a distal end. Accordingly, the sliding shaft slides toward the disk at the same time as the attraction magnet is attracted to the turntable and enters the clamp state, whereby the holding weight provided on the leaf spring member comes into contact with the balance weight to lock it. become.

The contact surface of the holding weight with the balance weight is formed with a spherical projection, and the contact surface of the balance weight with the holding weight is formed in a spherical concave shape. Both are partially fitted to each other, and the locked state at the time of rotation at a predetermined rotation speed or less is strengthened.

[0010] Further, a projection having a flat upper end is formed on the contact surface of the balance weight with the holding weight, so that the rotation of the disk increases and the holding weight comes off from the projection. Sometimes it is completely unlocked.

Further, the contact surface of the balance weight with the holding weight is formed as a tapered surface inclined along the radial direction of the clamp body, so that the rotation speed of the disk is mainly at a critical speed. When the number of rotations decreases from a low speed to a low speed, the holding weight comes into contact with the tapered surface of the balance weight and acts to assist the return movement of the balance weight to the center position.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a disk clamp device according to the present invention will be described below in detail with reference to the accompanying drawings.
1 is a schematic configuration diagram showing a disk device using the disk clamp device of the present invention, FIG. 2 is an enlarged sectional view showing the disk clamp device before mounting shown in FIG.
Is a perspective view of the disk clamp device shown in FIG. 2, FIG. 4 is an exploded view of the disk clamp device, FIG. 5 is an enlarged sectional view of the disk clamp device when mounted, and FIG. 6 is a plan view of the disk clamp device. Here, only the main mechanism components are shown, and the disk mounting mechanism, electric circuit components, exterior components, and the like are omitted.

First, the disk device will be described.
The disk device M writes information on and reads information stored on a disk 1 such as an optical disk or a magnetic disk. That is, the disk 1 is provided with the rotating shaft 2 of the spindle motor 2.
A is mounted on a turntable 3 fixed to the upper end of A, and rotates at high speed around a spindle central axis 5. The pickup 6 can be moved by the pickup moving means 7 in the radial direction of the disk 1 as shown by an arrow,
Information can be written to or read from the disk 1. The disk 1 is magnetically fixed between the disk 1 and the turntable 3 by the disk clamping device 8 of the present invention. Then, a balancer mechanism is integrally incorporated in the disk clamp device 8, and when the disk 1 is unbalanced, the unbalance of the disk 1 is corrected as the rotation speed of the disk 1 increases. The correction mechanism acts in the direction, and the generated vibration can be reduced.

As shown in FIGS. 2 and 5, the disk clamp device 8 has a clamp body 10 having a diameter of about 3 to 4 cm. The clamp body 10 is formed of, for example, a lower clamp base made of a magnetic material. 11 and an upper clamp base 12 made of, for example, tetrafluoroethylene and housed on the lower clamp base 11. On the lower surface of the bottom portion 13 of the lower clamp base 11, a frusto-conical mounting protrusion 3 provided at the center of the turntable 7 is provided.
A mounting hole 14 into which A is fitted is formed. A plurality of, in the illustrated example, six pawls 15 are provided on the peripheral edge of the lower clamp base 11 at equal intervals along the circumferential direction so as to stand up, and the pawls 15 are accommodated as described above. By engaging with the shoulder of the upper clamp base 12,
The two are combined.

A sliding shaft 16 is formed at the center of both clamp bases 11 and 12 so as to be slidable in the axial direction (vertical direction in the figure) without play by penetrating in the thickness direction. I have. Base (lower part) of this sliding shaft 16
In FIG. 1, a disk-shaped mounting plate 17 is received, and the mounting plate 17 is provided with a disk-shaped attracting magnet 18 having the same diameter to exert a clamping force. This attraction magnet 1
Reference numeral 8 denotes an attraction plate 19 made of a ring-shaped magnetic material provided on the mounting projection 3A having a truncated cone shape on the upper surface of the turntable 3.
And the disk 1 is clamped by the magnetic force. An integral body of the mounting plate 17 and the attraction magnet 18 is provided in a cylindrical hollow chamber 20 formed at a joint between the lower clamp base 11 and the upper clamp base 12, and together with the sliding shaft 16, a small amount is provided. It can be moved up and down by a certain distance, for example, a stroke of about several mm.

At the upper end of the sliding shaft 16, a spring holder 22 held by a claw 21 is provided.
A compression spring member 23 compressed between the spring holder 22 and the upper clamp base 12 is provided, and always biases the spring holder 22 upward. Here, the attraction force of the attraction magnet 18 at the time of clamping is set to be greater than the resilience of the compression spring member 23, and the sliding shaft 16 moves downward at the time of clamping. Also, upper clamp base 1
As shown in FIGS. 2 and 5, an annular balance weight 25 is slidably provided on the upper surface of the upper surface 2. The inner periphery of the balance weight 25 is connected to a flange portion 26 provided at the center of the upper clamp base 12 by a plurality of tension spring members 27 radially arranged at regular intervals along the circumferential direction. Thus, the annular balance weight 25 always acts toward the center.

In FIG. 6, the tension spring members 27 are arranged radially and uniformly in six directions about the spindle center axis 5, but the invention is not limited to this. For example, the tension spring members 27 are radially and uniformly arranged in three or four directions. You may make it. The balance weight 25 is located on the lower surface of the upper clamp base 12.
Although the upper clamp base 12 is made of tetrafluoroethylene or the like as described above,
This state of contact between the two surfaces has a very small coefficient of friction.

The sliding shaft 16 is sandwiched at its upper end with the spring holder 22 and extends radially at equal intervals from the center as shown in FIG. The leaf spring member 28 is fixed by being inclined downward. A spherical holding weight 30 is attached and fixed to the tip of each leaf spring member 28. When the holding weight 30 is not clamped, that is, when the sliding shaft 16 is slid upward,
As shown in FIG. 2, the upper surface of the balance weight 25 is separated from the upper surface of the balance weight 25 by a small gap. Conversely, when clamping, that is, when the sliding shaft 16 is slid downward, as shown in FIG. And simply presses the balance weight 25 downward with a predetermined force by the elastic force of the leaf spring member 28, restricts the movement of the balance weight 25 in the horizontal direction, and locks it. I have.

At this time, the elastic force or spring constant of the leaf spring member 28 is set so as to be substantially balanced with the centrifugal force applied to the holding weight 30 when the disk reaches the rotation speed of the critical speed, as described later. ing. In addition, the balance weight 2 is used so that the positioning of the spherical holding weight 30 becomes easy.
On the upper surface of 5, a spherical concave portion 31 is formed in a contact surface portion with the holding weight 30 when the rotation is stopped.

Next, the operation of this embodiment configured as described above will be described. First, the disk 1 is mounted on the turntable 3 and the disk clamp device 8 is mounted on the turntable 3 from above, so that the attraction plate 19 of the turntable 3 and the attraction magnet located below the disk clamp device 8 are mounted. The disc 1 sandwiched between the two is fixed on the turntable to perform clamping. At the time of unclamping, as shown in FIG.
Is urged upward by the resilient force of the compression spring member 23, the shaft 16 is slid upward, so that the holding weight 30 provided at the tip of the leaf spring member 28 is also slightly The holding weight 30 is separated from the upper surface of the balance weight 25.

However, when the clamping is performed as described above, the sliding shaft 16 also slides downward by the attraction force of the attraction magnet 18, whereby the leaf spring member 28 also moves downward by that amount. The holding weight 30 at the tip comes into contact with the upper surface of the balance weight 25, and furthermore, applies a predetermined load downward to the balance weight 25 by the elastic force of the leaf spring member 28. At this time, the lower portion of the spherical holding weight 30 is positioned in the concave portion 31 formed on the upper surface of the balance weight 25. Now, in the state where the clamping is completed, when the spindle motor 2 is stopped or when the spindle motor 2 is rotating at a rotation speed equal to or lower than the critical speed, the holding weight 30 is restored by the restoring force of the leaf spring member 28. A force acts on the balance weight 25 in the downward direction. Therefore, up to the rotation speed at the critical speed, the balance weight 25 is maintained without any sliding movement. However, when the rotation speed of the disc 1 becomes higher than the critical speed, the centrifugal force acting on the holding weight 30 becomes larger than the resilient force of the leaf spring member 28, and the leaf spring member 28 becomes A in FIG. Deform in the direction. That is, due to the centrifugal force, the holding weight 30 slightly rises upward as shown by a dashed line in FIG. 5, and as a result, a slight gap is formed between the holding weight 30 and the balance weight 25.

If the disk 1 has an unbalanced mass in this state, a plurality of tension spring members 2
The balance weight 25, which has been balanced by the resilience of the disc 7, moves to the opposite side to the unbalanced mass of the disk 1, that is, moves to the opposite side to the direction of the eccentricity, and the balance is automatically corrected. It is. As a result, even if the disk 1 rotates at a speed higher than the critical speed, the vibration caused by the imbalance is suppressed. Then, when the rotation speed of the disk 1 becomes low again, the sliding movement amount of the balance weight 25 also decreases and returns to the initial state. At the same time, the holding weight 30 whose centrifugal force has been reduced due to the decrease in the number of rotations also descends, and when the center of gravity of the balance weight 25 and the rotation center coincide with each other, the holding weight 30 is again positioned below the balance weight 25. The load is applied, and the state returns to the initial state. That is, the position of the balance weight 25 is returned to the original position.

As described above, in this embodiment, when the rotation speed is equal to or lower than the critical speed of the disk, the balance weight 25 is pressed by the pressing weight 30 and the leaf spring member 28 to be in a locked state. Even if there is a mass, the balance weight does not move in the direction of the eccentricity, and amplification of vibration is suppressed. When the number of rotations of the disk exceeds the critical speed, the locked state is released by the above-described operation, and the balance weight 25 is slid in the direction opposite to the eccentric direction to correct the imbalance. It is possible to automatically suppress the occurrence of excessive vibration that has an adverse effect.

Although the spherical holding weight 30 may have another shape, it is preferable that at least a portion in contact with the balancing weight 25 is spherical in order to effectively apply a load to the balancing weight 25. Also, here, a part of the spherical holding weight 30 is fitted into the concave portion 31 on the spherical surface provided on the surface of the balance weight 25, but this is because the position of the spherical holding weight 30 is easily determined. However, the spherical concave portion 31 may not be particularly provided. In the above-described embodiment, when the disk has reached the rotation speed of the critical speed or more, the locked state is established when the spherical holding weight 30 comes up against the elastic force of the leaf spring member 28 due to the centrifugal force applied thereto. As shown in FIGS. 7 and 8, an annular projection 35 having a flat upper end is provided on the contact surface of the upper surface of the annular balance weight 25 with the holding weight 30 as shown in FIGS. 7 and 8. May be provided. In this case, the width L1 of the plane at the upper end is set in such a state that even if the lower balance weight 25 slides even slightly, the holding weight 30 comes off the projection 35. Here, the protrusion 35 is provided in a ring shape, but the protrusion 35 may be provided not in a ring shape but in a portion only in contact with the holding weight 30.

In this embodiment, when the centrifugal force acting on the balance weight 25 overcomes the frictional force acting between the holding weight 30 and the balance weight 25 at a rotational speed higher than the critical speed, the balance weight 25 Work as a balancer. That is, as a result of the disk 1 having an unbalanced weight and an eccentricity, the centrifugal force becomes larger than the frictional force at a rotational speed higher than the critical speed, and the balance weight 25 is slightly opposite to the direction of the eccentricity. To the upper surface of the annular projection 35 provided on the upper surface of the balance weight 25.
In the state where is depressed, a gap is formed between the holding weight 35 and the balance weight 25, and the balance weight 25 moves as a balancer, thereby suppressing the occurrence of vibration.

The calibration or return of the position of the balance weight 25 is as described above. Here, as shown in FIG. 8, a case is shown in which three leaf spring members 28 are provided at equal intervals. Incidentally, for example, an optical disk generally rotates at a constant linear velocity as represented by a CD or a DVD. That is, the number of rotations differs depending on the radius of the reading (or writing) position, in other words, the radial position of the pickup. Further, the number of revolutions may greatly change depending on the seek state. At this time, there is a case where the balance weight 25 that can normally follow the fluctuation of the rotation speed cannot completely follow.

For example, this is a case where the pickup seeks from the innermost circumference to the outer circumference, and the number of revolutions changes from a high number of revolutions above the critical speed to a low number of revolutions below the critical speed. In rare cases, the weight of the balance weight 25 is slightly shifted from the center of gravity and the center of rotation.
May fall. However, also in this case, if the work of taking out the disk is performed, the balance weight 25 can be returned to the initial state, that is, the position of the balancer weight can be calibrated or returned. When the disk clamp device 8 separates from the turntable 3 when the disk 1 is taken out, the sliding shaft 16 moves upward by the action of the compression spring member 23. Then, the spherical holding weight 30,
The leaf spring member 28 also moves upward, and a slight gap is formed between the balance weight 25 and the holding weight 30. as a result,
The balance weight 25 can return to the initial state (a state where the center of gravity of the balance weight 25 coincides with the rotation center) from the balance of the force of the tension spring member 27.

The other embodiment shown in FIGS. 9 and 10 prevents the spherical holding weight 30 from being lowered when the center of gravity of the balance weight 25 and the center of rotation are slightly shifted as described above. Is what you can do. As shown in FIGS. 9 and 10, in this embodiment, the inner peripheral surface of the balance weight 25, which is in contact with the spherical pressing weight 30, is inclined downward inward in the radial direction of the clamp body 10. The tapered surface 36 is formed. Then, the spherical holding weight 30 comes into contact with the tapered surface 36. In the drawing, the angle of the tapered surface 36 with respect to the horizontal direction is appropriately selected from the relationship with the elastic force of the leaf spring member 28 and the tension spring member 27.

In this embodiment, when the disc 1 is stopped or rotating at a rotational speed less than the critical speed, the spherical holding weight 30 is moved by the leaf spring member 28 in the direction A shown in FIG. The pressing weight 30 is in close contact with the tapered surface 36 due to the load acting in the direction opposite to the above.
However, when the rotation speed of the disk 1 becomes higher than the critical speed, the spherical holding weight 30 moves in the direction A due to the centrifugal force, the balance weight 25 is released from regulation, and moves as a balancer in the direction opposite to the eccentric center. As mentioned earlier, FIG.
In the method shown in (1), the rotational speed of the disc 1 suddenly drops, and the spherical holding weight 30 falls on the balancer weight 25 due to a decrease in centrifugal force before the center of gravity of the balancer weight 25 matches the center of gravity of the clamp body 10. Can be avoided. That is, the balancer weight 25 is provided with a tapered surface 36, and as long as the spherical pressing weight 30 falls on the tapered surface 36, the spherical pressing weight 30 is restored by the restoring force of the leaf spring member 28. Sliding upward, the balance weight 25 moves to a position where the center of gravity coincides with the center of gravity of the clamp body 10, and calibration or return is quickly performed. That is, the spherical holding weight 30, the leaf spring member 28, and the tapered surface 36
As a result, the balance weight 25 is returned to the most stable position, that is, the position where the center of gravity of the balance weight 25 and the center of gravity of the clamp body 10 coincide with each other.

The apparatus of this embodiment can operate as a balancer even when the disk rotation axis is set perpendicular to the direction of gravity. That is, the balance weight 25 merely suspended by the radially extending tension spring members 27 is lowered by gravity when the disk is stopped by the action of gravity, so that the disk is rotated when the disk is restarted from a stopped state. When the number is low, the balance weight 25 is biased downward. However, in the apparatus shown in FIG. 9, the balance weight 25 and the center of gravity of the clamp body 10 can be kept in alignment when the disk is stopped even when the disk device M is set up vertically. As described above, the spherical holding weight 30 has a tapered surface 36.
This is because the balance weight 25 slides upward and moves so that its center of gravity and the center of gravity of the clamp body 10 coincide. Therefore, when the rotation speed is equal to or lower than the critical speed after the restart, the balance weight 25 is not biased.

It goes without saying that the surfaces of the tapered surface 36 and the spherical holding weight 30 are smooth. Further, in the embodiment shown in FIG. 9, the taper surface 36 is shown as being provided on the inner peripheral surface of the balance weight 25.
6 may be provided on the outer peripheral surface, that is, provided so as to be inclined downward toward the outside in the radial direction of the clamp body 10, and the spherical holding weight 30 may be in contact with the tapered surface 36. Further, in each of the above-described embodiments, the spherical holding weight 30 is used. However, instead of the spherical holding weight, a weight having a three-dimensional structure having a hemispherical or non-spherical curved surface shape may be used. Also,
It is preferable that the positions of the leaf spring member 28 and the spherical holding weight 30 have a minimum height from the disk.

[0032]

As described above, according to the disk clamp apparatus of the present invention, the following excellent functions and effects can be exhibited. At a rotational speed less than the critical speed of the disc, the balance weight is pressed down and locked by the elastic force of the leaf spring member, so that the balance weight moves in the same direction as the unbalanced mass (direction of eccentricity). At a rotation speed higher than the critical speed, the lock state is automatically released by the centrifugal force applied to the holding weight, the balance weight moves to the opposite side to the eccentric direction,
Unbalance weight can be corrected. In addition, by making the upper surface of the balance weight that the holding weight comes into contact with a tapered surface, the position of the balance weight is the center position even if the rotational speed of the disk suddenly drops from the rotational speed above the critical speed to the rotational speed below the critical speed. Can be calibrated. Furthermore,
Even if the disk device is installed so that the rotation axis of the disk is perpendicular to the direction of gravity, the position of the balance weight can be automatically calibrated to the center position when the disk is stopped.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a disk device using a disk clamp device of the present invention.

FIG. 2 is an enlarged sectional view showing the disk clamp device before mounting shown in FIG. 1 and a peripheral portion thereof.

FIG. 3 is a perspective view of the disc clamp device shown in FIG. 2;

FIG. 4 is an exploded view of the disk clamp device.

FIG. 5 is an enlarged cross-sectional view of the disk clamp device when mounted.

FIG. 6 is a plan view of the disk clamp device.

FIG. 7 is an enlarged sectional view showing another embodiment of the present invention.

FIG. 8 is a plan view of the device shown in FIG. 7;

FIG. 9 is a further enlarged cross-sectional view showing another embodiment of the present invention.

FIG. 10 is a plan view of the device shown in FIG. 9;

FIG. 11 is an enlarged sectional view showing an example of a conventional balancer mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Disc, 2 ... Spindle motor, 3 ... Turntable, 6 ... Pickup, 8 ... Disk clamp device,
10 Clamp body, 11 Lower clamp base, 12
... upper clamp base, 16 ... sliding shaft, 18 ... attracting magnet, 23 ... compression spring member, 25 ... balance weight, 2
7: tension spring member, 28: leaf spring member, 30: holding weight, 31: concave portion, 35: projection portion, 36: tapered surface,
M: Disk device.

Claims (2)

[Claims] 1. A disk clamping device for magnetically clamping a disk placed on a turntable, comprising: a clamp body which can be attracted to the turntable by magnetic force; An annular balance weight provided, a plurality of tension spring members for applying a tensile force to the rotation center side of the clamp body with respect to the balance weight, and a holding weight contacting the balance weight at a tip end, A leaf spring member having a base end connected to the rotation center side of the clamp main body to bias the balance weight toward the clamp main body with a predetermined elastic force; and when the clamp main body has a predetermined rotation speed or more. The holding weight is separated from the balance weight against the urging force of the leaf spring member by centrifugal force. A disk clamp device characterized by comprising. 2. A clamp shaft is provided at the center of the clamp body so as to be slidable along the center of rotation, and the clamp body is attracted to the turntable side at the base end of the slide shaft. 2. The disk clamp apparatus according to claim 1, wherein a suction magnet is provided, and a base end of the tension spring member is fixed to a front end.