JP2764285B2 - Rotary positioning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to rotary positioning for performing rotary positioning in fields such as electronic devices such as floppy disks, hard disks, and optical disks, ultra LSI manufacturing, and microscopic measurement. It concerns the device.

[Prior Art] Conventionally, a rotary positioning device shown in FIG. 4 has been used for rotary positioning in the field of electronic devices such as hard disks.

In this device, a spring 33 is coupled above a rotary bar 32 supported by a rotary sliding bearing 34, one end of a transmission spring belt 31 is fixed below, and the other end of the transmission spring belt 31 is connected to a pulse motor 30. The magnetic head 36 is attached to the tip of the rotating bar 32.
Is positioned on the disk 35.

By rotating the pulse motor 30, the transmission spring belt
When the rotary bar 32 rotates downward, the rotary bar 32 rotates downward.When the pulse motor 30 is rotated in the reverse direction, the rotary bar 32 rotates upward. 32 and the magnetic head 36 can be precisely displaced.

[Problems of conventional technology]

However, the rotation positioning motor as described above could not be driven at high speed due to the vibration of the transmission spring belt 31 and the inertia of the rotary bar 32.

For example, if the material of the transmission spring belt 31 is SUS304-CS
P, 0.1 mm thickness (t), 6 mm width (w), if the maximum length 40mm lengths (l), the lowest natural frequency f ₀ is given by the following equation.

Where E: Young's modulus I: Screw moment ρ: Density The angular velocity δ is given by the following equation.

δ = f ₀ · a = 152 [deg / sec] where a = average angle magnification = 4 That is, the moving speed (angular speed) of the magnetic head 36 is 152 deg / s.
If it is more than ec, the transmission spring belt 31 will vibrate and it will be difficult to perform accurate positioning. Therefore, the moving speed can be limited to only about 152 deg / sec at a maximum, and it is not fast.

In addition, the transmission spring belt 31 and the rotary bar 32 have a large dimensional change due to a temperature change, and the rotation positioning accuracy cannot be increased.

Therefore, when this rotary positioning device is used, for example, for driving a magnetic head, it has been difficult to read and write information at a low speed and to cope with higher-density information recording.

[Means for solving the problem]

In view of the above, the present invention forms a rotation support portion inside a frame-shaped base, and attaches a plurality of actuators to the other end side of a floating body arranged such that one end is in sliding contact with the rotation support portion. A foot member is attached to the tip of the actuator, and the tip of the foot member is pressed against a slip plate formed inside the base, and an actuator is attached between the foot members to constitute a rotation positioning device. .

〔Example〕

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

As shown in FIGS. 1 (a) and 1 (b), the rotary positioning device of the present invention forms a substantially columnar rotary support portion 2 integrally with the base 1 inside the frame-shaped base 1, The floating body 3 is arranged so as to be in sliding contact with the rotation support portion 2. The floating body 3 is rotatable in the direction of the arrow by sliding with the rotation support section 2 at the rotation slide section 3c.

Further, bending portions 3a and 3b which are thin in two directions extending radially from the rotation supporting portion 2 are formed at an end of the floating body 3 opposite to the rotation sliding portion 3c, and the tip of the bending portion 3a is formed. , An actuator 4 and a foot member 5 are attached to the distal end of the bending portion 3b, respectively. The actuator 8 is also connected between the leg members 5 and 7, but if the strain gauge 9 for measuring the amount of expansion and contraction is attached to the actuator 8, more precise movement becomes possible.

Further, a slip plate 10 having a circumferential shape around the rotation support portion 2 is integrally formed inside the base 1,
The foot members 5, 7 are in contact with the slip plate 10. In addition, the slip plate 10 is molded as a separate body,
It may be connected to the inside of the base 1. Also, foot members
Thin flexible portions 5a, 7a are formed in the portions 5, 7, and the contact surfaces 5b, 7b with the slip plate 10 are circumferential surfaces around the flexible portions 5a, 7a.

Further, in the vicinity of the rotation supporting portion 2 of the base 1, thin portions 11 and 11 for adjusting the gap in the vertical direction and an adjusting screw 12, and thin portions 13 and 13 for adjusting the gap in the horizontal direction and adjusting screws 14 and 14 are provided. The adjustment screws 12, 14, 14 make it possible to correct variations in the gap between the foot members 5, 7 and the slip plate 10 during manufacturing.

Further, a rotating member 16 is connected to the floating body 3 by a bolt 15, and the rotating member 16 can be freely moved according to the movement of the floating body 3. For example, if a magnetic head is attached to the tip of the rotating member 16, it can be used for a rotation positioning device for a magnetic head of a hard disk as shown in FIG.

This rotary positioning device has three actuators 4, 6,
8 rotates the floating body 3 by an inching ohm operation that repeats expansion and contraction with each other. The detailed operation is as follows.

As shown in the time chart of FIG. 3, in the case of clockwise rotation, first, the actuator 4 contracts and the foot member 5
Is released from the slip plate 10 or the pressing force is reduced, and then the actuator 8 contracts, so that the foot member 5 moves downward in the drawing. Here, the actuator 4 is extended, and the foot member 5 is a slip plate.
Pressed to 10. Next, when the actuator 6 contracts, the foot member 7 separates from the slip plate 10 or the pressing force is reduced, and then the actuator 8 is extended to move the foot member 7 downward in the drawing. Here, the actuator 6 is extended, the foot member 7 is pressed against the slip plate 10, and one cycle is completed. At this time, the foot members 5 and 7 have moved downward by the amount of expansion and contraction of the actuator 8, and the floating body 3 has been slightly rotated clockwise about the rotation support 2 as the rotation center. The counterclockwise rotation can be performed by reversing the above operation.

Therefore, the rotation angle can be freely adjusted by setting the amount of expansion and contraction of the actuator 8 and the number of cycles so that the floating body 3 has the required rotation angle.

Further, the triangle formed by the floating body 3, the foot members 5, 7 and the actuators 4, 6, 8 connecting these move with the above-mentioned inching ohm operation, while being slightly distorted. However, since the bending portions 3a and 3b of the floating body 3 and the bending portions 5a and 7a of the foot members 5 and 7 are formed, the triangular distortion can be absorbed by these bending portions.
The coupling relationship between each of the actuators 4, 6, 8 and the floating body 3, and the leg members 5, 7 is not impaired.

Furthermore, the contact surface 5 of the foot members 5, 7 with the slip plate 10
Since b and 7b have curved surfaces, the distortion of the triangle can be absorbed.

In addition, when the foot members 5 and 7 are symmetrical with respect to the central axis extending radially from the rotation supporting portion 2, the balance is improved and excellent.

In the above embodiment, the rotary support 2 formed integrally with the base 1 has a cylindrical shape, and the rotary sliding portion 3c of the floating body 3 has a concave shape. As described above, a cylindrical rotary sliding portion 3c may be formed on the movable body 3 side, and a concave rotary support portion 2 may be formed on the base 1 side, and other various shapes may be employed.

Further, in the above-described embodiment, the one having two foot members 5, 7 is shown. However, it is also possible to equip three or more foot members with the same structure, and to attach the actuator to each foot member. .

Next, a prototype of the rotary positioning device shown in FIGS. 1A and 1B was manufactured, and various performance tests were performed.

The overall size is 40 mm in length, 40 mm in width, and 6 mm in thickness. The base 1, the floating body 3, and the foot members 5, 7 are all made of zirconia ceramic, and the contact surfaces of the foot members 5, 7 with the slip plate 10 are provided. 5b and 7b are mirror surfaces of 0.8 s or less. Each of the actuators 4, 6, and 8 used a piezoelectric actuator in which a plurality of piezoelectric ceramics were laminated. The piezoelectric actuator is capable of performing minute expansion and contraction by adjusting the applied voltage.
m. The method of joining the actuators 4, 6, 8 with the floating body 3, and the foot members 5, 7 is such that a metal layer is formed in advance on a joint surface of each other by metallizing or the like, and the metal layers are fused together. It is.

The performance of such a rotary positioning device has a step feed resolution of about several seconds and an angular velocity of 60
It was excellent at 0 degrees.

In addition, the rotatable range in which the floating body 3 can slide and move with the rotation support portion 2 becomes large.

1-step angle 1-70 seconds (angle) variable 1-step accuracy ± 3 seconds (angle) Maximum speed 30,000step / second (600 degrees / second) Positioning stability ± 1 second (angle) / hour Various materials such as ceramics and metals can be used as the material such as 3, but ceramics such as alumina and zirconia are more preferable because of their small linear expansion coefficient and excellent wear resistance.

〔The invention's effect〕

As described above, according to the present invention, a rotary support portion is formed inside a frame-shaped base, and a plurality of actuators are mounted on the other end side of a floating body arranged such that one end is in sliding contact with the rotary support portion. And a foot member is attached to the tip of each actuator, and the tip of the foot member is pressed against a slip plate formed inside the base body, and an actuator is attached between these foot members to constitute a rotation positioning device. By doing so, it is possible to provide a high-performance rotation positioning device, such as high-speed rotation with low energy, a wide rotatable range, and extremely high-precision positioning.

[Brief description of the drawings]

FIG. 1 (a) is a side view showing a rotary positioning device according to the present invention, and FIG. 1 (b) is a sectional view taken along line AA 'in FIG. 1 (a). FIG. 2 is a sectional view showing another embodiment of the present invention. FIG. 3 is a time chart showing the expansion and contraction operation of each actuator for explaining the operation of the rotary positioning device according to the embodiment of the present invention. FIG. 4 is a perspective view showing a conventional rotary positioning device. 1: Base, 2: Rotary support 3: Floating body, 4, 6, 8: Actuator 5, 7: Foot member, 10: Slip plate

Claims (1)

(57) [Claims] A rotary support is formed inside a frame-shaped base, and a plurality of actuators are attached to the other end of a floating body arranged such that one end is in sliding contact with the rotary support. A rotary positioning device having a foot member attached to a tip thereof, a tip of the foot member pressed against a slip plate formed inside the base, and an actuator attached between the foot members.