JPH04278253A - Disk clamping device - Google Patents

Abstract

PURPOSE:To reduce impact and load on the bearing of a rotary driving device when a disk is attached to and removed from a turntable and to achieve the low cost of a clamping device. CONSTITUTION:A center ring 33 having the tapered surface is provided for determining the central position of a disk 1. Clamp levers 40 for fixing the disk 1 are provided at a plurality of places in the inner space of a turntable 32. The clamp levers 40 are moved by the turning with a pulling spring 42 of a cam member 41 and a brake shoe 45, and the disk 1 is fixed to the turntable 32 with a clamp pawl 40a.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc clamping device for fixing a disc in an optical disc player.

0002

2. Description of the Related Art In optical disc players, a disc clamp device is used which engages with a clamp hole opened in the center of the disc to attach and remove the disc from a rotary drive device. An example of a conventional disk clamp device will be described below. FIG. 3 is a sectional view showing an example of a conventional disk clamp device (first conventional example). In this figure, a turntable 2 on which a disk 1 is placed is made of a magnetic material, and is fixed to a rotating shaft 4 of a spindle motor 3 with a lock screw 2a. The center ring 5 has a truncated conical outer shape, and the center ring 5 has a truncated cone shape, and the center ring 5 has a truncated conical outer shape,
It is fitted onto the rotating shaft 4 for positioning coaxially with the rotating shaft 4. In order to press the center ring 5 upward, a pressing spring 6 is provided coaxially with the rotary shaft 4 and embedded in the central recess of the turntable 2. A retaining ring 7 is attached to the end of the rotating shaft 4 in order to stop the center ring 5 urged by the pressing spring 6 at a specific position on the rotating shaft 4. The outer circumferential side surface of the center ring 5 is a tapered surface 5a, and this tapered surface 5a positions the disk 1 at the center of rotation by fitting with the end surface of the clamp hole 8 of the disk 1. A rubber plate 9 is bonded to the disk mounting surface of the turntable 2, and due to the friction thereof, rotational torque is applied from the turntable 2, and the disk 1 rotates together with the turntable 2. The clamper 10 holds the disk 1 on the turntable 2, and has an annular permanent magnet 11 on a part of the surface facing the disk 1. Also, in the groove provided on the outer peripheral side of the clamper 10,
Clamp operating plate 1 that defines the movement range of the clamper 10
2 are fitted.

To mount the disc 1 on the turntable 2, the disc 1 is conveyed to the vicinity of the mounting surface of the turntable 2 by a disc guiding means (not shown). By lowering the clamp operating plate 12 in the direction shown by arrow A from the open state of the clamper 10, the clamp hole 8 of the disk 1 is fitted into the center ring 5. Furthermore, the magnetic attraction force between the permanent magnet 11 and the turntable 2 strongly presses the disk 1, and the disk 1 is fixed coaxially with the turntable 2 via the tapered surface 5a.

Next, when the spindle motor 3 is rotated, the disk 1 is rotated via the turntable 2. At this time, the disk 1 is attached to the center ring 5 by the clamp hole 8.
Since it is held coaxially by the tapered surface 5a, it rotates at a position on the axis where the elasticity of the presser spring 6 and the magnetic force of the permanent magnet 11 are balanced. To stop the rotation of the spindle motor 3 and release the fixation of the disk 1 from a state in which the disk 1 is fixed to the turntable 2 and rotating, the clamper 10 must be moved away from the turntable 2 by moving the clamper 10 away from the turntable 2 by overcoming the magnetic force of the permanent magnet 11. It is necessary to pull it away in direction B.

FIG. 4 is a sectional view showing the structure of another conventional disk clamping device (second conventional example). The turntable 2, spindle motor 3, center ring 5, etc. are the same as those in the first conventional example shown in FIG. However, in this figure as well, the disk 1 is placed on the turntable 2 via the rubber plate 9, but is fixed by a clamper 21 having a structure different from that of the first conventional example. This clamper 21 does not include a permanent magnet, but is provided with a mechanism for applying pressure in the direction shown by arrow C from the outside on the back side of the disk pressing surface. A cylindrical groove 22 is cut out in the center of the axis of the clamper 21, and a steel ball 23 is embedded therein. On the other hand, the bearing 24 that presses the steel ball 23 is connected to the arm 25.
is attached to. This arm 25 is held at its right end (not shown), and its left end is biased downward by a coiled spring 26.

With this configuration, the clamper 21 is pressed by the arm 25, and the steel ball 23 receives contact pressure from the bearing 24, thereby pressing the disc 1 against the turntable 2. Further, the rotating shaft 4 of the spindle motor 3 receives a load in its axial direction, causing the disk 1 to rotate. To stop the spindle motor 3 and release the disk 1 from the turntable 2, the arm 25 can be moved in the direction shown by arrow D against the spring 26.

[0007]

However, in the first conventional example, the pressing force for fixing the disk 1 to the turntable 2 is obtained by the attraction force of the permanent magnet 11, but this force is not applied to the permanent magnet 11 and the turntable. Depends on the gap between table 2,
In particular, it changes depending on the thickness of the rubber plate 9. Furthermore, the turntable 2 must be made of a magnetic material, which is disadvantageous in terms of cost compared to materials such as resin moldings, which are relatively inexpensive and suitable for production. Furthermore, when attaching or detaching the disk 1, the clamper 10 is pulled apart against the attraction force of the permanent magnet 11, so that the rotating shaft 4 of the turntable 2 and spindle motor 3
is also pulled at the same time, giving a thrust load to the bearing, which is an important component of the spindle motor 3, which has a negative effect on performance and life.

Further, in the disk clamp device shown in the second conventional example, steel balls 2 are used to transmit the pressing force to the disk 1.
3, a bearing 24, and a groove 22, and a thrust load is applied to the spindle motor 3 by the friction load of this part. This adversely affects the performance and life of the spindle motor 3, and there is also the problem that the steel balls 23, bearings 24, etc. are likely to wear out.

Furthermore, in the first and second conventional examples, each component for fixing the disc 1 to the turntable 2 is constructed above the disc mounting surface, so there is a drawback that the height of the entire device becomes large. there were.

The present invention has been made in view of the above-mentioned problems of the conventional art, and is designed to reduce the height of an optical disc player and to provide a component for use in a clamp device.
The purpose is to reduce the cost of the device by using inexpensive materials such as resin and general metal without using permanent magnets or magnetic materials. Another purpose is to eliminate the thrust load applied to the rotating shaft of the spindle motor, thereby improving the reliability and extending the life of rotational drive devices such as the spindle motor.

[0011]

[Means for Solving the Problems] The present invention is a disk clamping device for removably holding a disk having a clamp hole opened in the center on a rotary drive device, in which the disk is fixed to the main shaft of the rotary drive device. A center ring is fitted into the turntable on which it is placed and the main shaft of the rotary drive device, has a tapered outer circumferential side surface, and holds the disk in the center position by holding the clamp hole of the disk with the outer circumferential side surface. , a first end that is attached to the lower part of the turntable and is rotatably held in the radial direction of the turntable, and that protrudes outward from the outer circumferential side of the center ring, and a second end that has a sliding surface. a cam member having one end abutting the sliding surface of the second end of each clamp lever;
and a tension spring that fixes the disk by the end of the disk.

0012

[Operation] According to the present invention having such features, the clamp lever is avoided into the center ring via the cam member while the rotational drive device is stopped. At this time, the first end holding the clamp hole of the disc is retracted, and the disc is removed from the turntable. In order to fix the disc to the turntable, first, the clamp hole of the disc is fitted into the tapered outer peripheral side of the center ring, and the disc is positioned coaxially with the turntable. Next, the cam member is rotated, and the tension spring causes the clamp lever to rotate toward the edge of the clamp hole of the disk. At this time, the disk is fixed to the turntable by the first end of the clamp lever. On the other hand, the outer peripheral side surface of the cover is pressed against the rotary drive device that is about to stop, and the turntable becomes unable to rotate.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a state in which a disk of a disk clamp device according to an embodiment of the present invention is fixed. In this figure, disk 1, which is a recording medium,
The rotating shaft 31 of the spindle motor 31 rotates the
A turntable 32 is attached to a by a lock screw 32a. A center ring 33 having a truncated conical outer shape is fitted into the end of the rotating shaft 31a, and is held in a fixed position on the rotating shaft 31a by a compression spring 34 and a retaining ring 35 inserted coaxially with the rotating shaft 31a. center ring 33
The outer peripheral side surface of the disc 1 has a tapered surface that is machined with high precision and is symmetrical with respect to the rotational axis, and the disc 1 is positioned on the turntable 32 by inserting the clamp hole 8 of the disc 1. Further, inside the center ring 33, a space is provided to accommodate various members for fixing the disk 1, and openings are provided at two locations on the outer periphery of the center ring 33 at intervals of 180 degrees.

On the other hand, two sets of clamp members 36 for fixing the disk 1 to the lower surface of the turntable 32 are attached at positions symmetrical to the rotation axis. Clamp member 36
The following members are included: board 38, pin 39, clamp lever 40, cam member 41, pin 41a, and tension spring 42.
Consists of etc. The board 38 is a mounting plate vertically fixed to a part of the bottom surface of the turntable 32.
A clamp lever 40 is rotatably supported by a pin 39 on the top 8. The clamp lever 40 is an L-shaped lever with a first lever that protrudes upward from the turntable 32.
and a second end having a sliding surface on the cam member 41 side. A first end of the clamp lever 40 is provided with a clamp pawl 40 a that has an outwardly facing wedge surface and engages with the clamp hole 8 of the disk 1 . This wedge surface is formed of an inclined part 40b that presses the upper edge of the clamp hole 8, and an inclined part 40c that prevents collision between the clamp claws 40a when they are stored in the internal space of the center ring 33. There is. On the other hand, the second end of the clamp lever 40 has a sliding surface 40 bent parallel to the disk mounting surface.
d and a hole for tensioning the spring. The cam member 41 rotates the clamp lever 40 within a predetermined range, and is supported on the base plate 38 . Cam member 4
1 is the sliding surface 4 of the clamp lever 40 centered on the pin 41a.
The cam portion 41b that contacts the cam portion 0d and the arm 41c that rotates the cam portion 41b by an external pressure force are integrally constituted in a lever shape. The tension spring 42 is connected to the sliding surface 40d of the clamp lever 40 and the lower part of the base plate 38.

A cylindrical cover 43 that covers the clamp member 36 is attached to the lower side surface of the turntable 32. A plurality of openings 43a are provided in a portion of the outer peripheral surface of the cover 43 that is close to the mounting surface of the spindle motor 31. Further, above the spindle motor 31, a brake guide 44 is disposed circumferentially on the lower surface of the cover 43. Further, a brake shoe 45 is attached to the inner peripheral side of the brake guide 44, and is configured to press the arm 41c inwardly by a driving source such as an electromagnetic plunger (not shown).

Next, the operation of the disk clamping device of this embodiment will be explained. FIG. 2 is a sectional view of the disc clamping device according to this embodiment, showing a state in which the disc is not fixed. When a disc 1 is placed on a transport stand in an optical disc player, the disc 1 is transported to the center of the turntable 32 by a disc transport device (not shown). In this state, as shown in FIG. 2, the spindle motor 31 stops rotating, and the brake shoe 45 is driven in the direction of the rotating shaft 31a. Therefore, the brake shoe 45 presses the arm 41c of the cam member 41 inward. By pushing the end face of the arm 41c in the direction shown by arrow G, the radius of rotation of the cam portion 41b increases, pushing up the sliding surface 40d. Therefore, the clamp lever 40 rotates in a direction to retreat from the edge of the clamp hole 8, and the clamp claw 40a retreats toward the rotating shaft 31a. Also brake shoe 45
is in contact with the outer peripheral side surface of the cover 43, and the turntable 32 is fixed by its friction brake.

Next, when the disk 1 is moved to the turntable 32 side by the disk transport device and lowered downward at this position, the clamp hole 8 is fitted into the center ring 33 while coming into contact with the tapered portion 33a. The disk 1 fitted coaxially with the rotating shaft 31a is placed on the rubber plate 9 of the turntable 32, but more precisely, the disk 1 is placed on the rubber plate 9 of the turntable 32.
It is not necessarily held parallel to the mounting surface of 2.

Next, when the brake shoe 45 is released from the state shown in FIG. 2 to the outside of the rotating shaft 31a by the driving source as shown in FIG. rotates in the direction shown by arrow H. Then, the clamp lever 40 rotates in the direction of the arrow G, and the clamp claw 40a is inserted into the clamp hole 8 of the disk 1.
move to the edge of the Then, the inclined portion 40b of the clamp claw 40a engages with the edge of the clamp hole 8, and the inclined portion 40b engages with the edge of the clamp hole 8.
The disc 1 is pressed against the turntable 32 side by b. At this time, the clamp hole 8 of the disk 1 is pressed against the turntable 32 while coming into contact with the tapered portion 33a of the center ring 33, and the disk 1 is clamped while being positioned at the center of the rotation drive device. . As shown in FIG. 1, when the disc 1 is completely fixed to the turntable 32, the brake shoe 45 is retracted to a position where it does not come into contact with the cover 43, so by driving the spindle motor 31, the disc 1 is It can be rotated while being fixed to the turntable 32.

Next, to stop the rotation of the disk 1, an electric brake is applied to the spindle motor 31. This braking torque causes the rotational speed of the spindle motor 31 to drop to the point where it almost stops, and at this point the brake shoe 45 is activated. By doing so, the brake shoe 45 is connected to the cam member 41.
The cam portion 41b comes into contact with the arm 41c, and the cam portion 41b rotates in the direction of arrow G. Therefore, the clamp lever 40 also rotates, and the clamp claw 40a separates from the edge of the clamp hole 8. At the same time, the brake shoe 44 also comes into contact with the cover 43, so the turntable 32 is stopped via the cover 43. The clamp claw 40a retreats from the opening 33b of the center ring 33 toward the central axis, and the fixed hold on the disk 1 is released. After this, the clamp hole 8 is connected to the tapered part 3.
The disk 1 is removed without being blocked from 3a.

In this embodiment, the clamp member 36 is provided at two locations symmetrically to the rotating shaft 31a, but by miniaturizing each component constituting the clamp member 36, three locations are provided at 120° intervals relative to the rotating shaft. It is also possible to provide one.

[0021]

Effects of the Invention As described above in detail, according to the inventions of claims 1 to 4 of the present application, a rotatable clamp lever is provided inside the center ring that holds the disk at the center position of the rotary drive device. , the disc is fixed to the turntable via the edge of the clamp hole of the disc. Therefore, it is not necessary to configure the turntable with a magnetic material or to provide a permanent magnet in the clamper that presses the disk. Therefore, the clamp member can be made of an inexpensive material such as resin or metal, and the price of the clamp device can be reduced. Also, to release the fixation of the disc, the clamp lever must be rotated via the cam member, so
The clamp claw is easily removed from the clamp hole of the disk, and the disk can be removed from the turntable without applying an axial tensile load to the rotating shaft of the spindle motor. It is possible to realize an excellent disk clamping device that eliminates the thrust load of the spindle motor when attaching and detaching the disk, thereby improving the reliability and extending the life of the rotary drive device. Furthermore, since the clamp lever and cam member for holding the disc are installed between the turntable and the spindle motor, the upper surface of the disc is simplified, and the thickness of the optical disc player can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a state in which a disk is fixed in a disk clamp device according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a state in which the disk is released from being held in the disk clamping device of this embodiment.

FIG. 3 is a sectional view showing the configuration of a disk clamp device in a first conventional example.

FIG. 4 is a sectional view showing the configuration of a disk clamp device in a second conventional example.

[Explanation of symbols]

1 Disc 8 Clamp hole 31 Spindle motor 31a Rotation axis 32 Turntable 33 Center ring 33a Taper part 33b Opening 34 Compression spring 36 Clamp member 38 Board 39 pin 40 Clamp lever 40a Clamp claw 40b, 40c　Slope part 40d Sliding surface 41 Cam member 41a pin 41b Cam part 41c arm 42 Pull spring 43 Cover 43a Opening 44 Brake guide 45 Brake shoe

Claims (4)

[Claims] 1. A disk clamp device that removably holds a disk having a clamp hole opened in the center on a rotary drive device, the turntable being fixed to a main shaft of the rotary drive device and on which the disk is placed. a center ring that is fitted into the main shaft of the rotary drive device, has a tapered outer circumferential side surface, and holds the disk at a central position by holding the clamp hole of the disk with the outer circumferential side surface; a first end that is attached to a lower part of the table and is rotatably held in the radial direction of the turntable, and that protrudes outward from the outer circumferential side of the center ring, and a second end that has a sliding surface; a cam member having one end in contact with a sliding surface of a second end of each of the clamp levers, and a puller that biases the clamp lever and fixes the disk by the first end thereof. A disk clamp device comprising a spring. 2. The first end of the clamp lever includes:
a wedge-shaped portion that engages with the clamp hole of the disk;
2. The disk clamp device according to claim 1, wherein the disk is fixed to the turntable by the wedge surface. 3. The cam member has a cam part that comes into contact with the second end of the clamp lever, and an arm that is integrally formed on the side facing the cam rotation axis, 2. The disk clamp device according to claim 1, further comprising a brake shoe that faces the arm and releases the fixation of the disk by the first end of the clamp lever when pressed. 4. A cylindrical part that accommodates the cam member and the tension spring, faces the brake shoe and rotates together with the turntable, and the brake shoe is pressed against the outer peripheral surface of the cylindrical part. 4. The disk clamp device according to claim 3, wherein the turntable is stopped from rotating.