JPH07182045A - Fine positioning driving mechanism - Google Patents

Abstract

PURPOSE:To provide a fine positioning mechanism by a mum unit with a long stroke by constituting a fine positioning driving mechanism composed of a piezoelectric actuator guiding member, a piezoelectric actuator, a micrometer and a pulley. CONSTITUTION:The knob part 8c of the micrometer 8 is rotated and a stage 27 is driven through a ball 21, the piezoelectric actuator 1 and the ball 22. At the time, driving adjustment is performed upto the unit of the minimum scale of the micrometer 8. Then, when a voltage is impressed to the piezoelectric actuator 1, a piezoelectric element 1-1 is extended. At the time, the stage 27 is finely driving adjusted by the mum unit. When the adjustment can not be performed even when the voltage is raised to maximum, the piezoelectric actuator 1 is reduced by tentatively lowering the voltage and the micrometer 8 is rotated in fixed torque by the pulley 19 and a weight 20 and is pressurized onto the piezoelectric actuator 1. Then, again, the voltage is impressed until th stage 27 is adjusted to a desired dimension.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine positioning drive mechanism used for a fine positioning stage or the like.

[0002]

2. Description of the Related Art Conventionally, there is a fine positioning mechanism using a piezoelectric actuator 1 as shown in FIG. The characteristic is that the piezoelectric element 1-1 expands and contracts when a voltage is applied to the piezoelectric element 1-1 through a cord 3 and a connector 2 from a power source (not shown). (FIG. 2) shows two types of piezoelectric elements 1 having different total lengths.
FIG. 3 is a voltage-displacement characteristic diagram showing the state of displacement change when the applied voltage is changed to −1. L1 indicates a state where the total length of the piezoelectric element is 18 mm, and L2 indicates a state where the total length is 9 mm. As is clear from (FIG. 2), the maximum displacement amount is shown to be proportional to the total length L of the piezoelectric element. That is, when a large amount of displacement is required, the total length L of the piezoelectric element is
Requires a long piezoelectric element. (Figure 3), (Figure 4),
FIGS. 5 and 6 are a plan view, a side view, an AB cross sectional view, and a CD view of a stage having a conventional fine positioning mechanism, respectively, when a resolution of several nanometers is required.
A cross-sectional view is shown. The function of the micrometer 8 and the function of the piezoelectric actuator 1 are used together. 6 is
A base 5 is a slide stage that slides on the base 6. The slide stage 5 is provided with a protrusion 5a for receiving a slide drive. A micrometer receiver 7 is provided on the side surface of the base 6 with screws 7-
2 and the micrometer 8 is fixed with a screw 7-1. Further, the piezoelectric actuator receiver 9 is fixed to the side surface of the substrate 6 with a screw 9-1, and the piezoelectric actuator 1 is attached to the upper surface of the piezoelectric actuator receiver 9.
Is slidably placed. Guide protrusions 9-2 and 9-3 are provided on the upper surface of the piezoelectric actuator receiver 9. In the stage with the fine positioning mechanism configured as described above, first, the micrometer 8 is operated to perform positioning in units of 0.01 mm, which is generally the minimum scale, and then the voltage is applied to the piezoelectric actuator 1. Is applied to perform fine positioning of several nm to several tens of μm. In this case, it is desirable that the piezoelectric actuator 1 be capable of fine positioning up to 0.01 mm, which is the minimum unit of the micrometer 8. However, as is clear in (Fig. 2), L2
When (total length 9 mm) is used, only 9 μm can be adjusted. Therefore, the minimum unit of the micrometer 8 is 0,01 mm
Is adjusted by the piezoelectric actuator 1, L1
The piezoelectric actuator 1 having a total length of 18 mm must be used. Manufacturing the piezoelectric actuator 1 having a long total length has a drawback that the cost is high. Further, if the piezoelectric actuator 1 having a long overall length is used, there is a drawback that the structure becomes large accordingly.

[0003]

SUMMARY OF THE INVENTION According to the present invention, even if the piezoelectric actuator 1 having a short overall length is used, the voltage applied to the piezoelectric element 1-1 is repeatedly increased / decreased, so-called
It is an object of the present invention to provide a fine positioning mechanism having a long stroke in the unit of μm by causing the piezoelectric actuator 1 to perform an insect-like movement.

[0004]

[Means for Solving the Problems] A fine positioning drive mechanism for a finely driven member, comprising a piezoelectric actuator guide member, a piezoelectric actuator, a micrometer, and a pulley for rotating the micrometer with a constant torque. To do.

[0005]

First, the driven member is positioned by the micrometer up to the minimum unit of 0,01 mm. Next, apply a voltage up to the specified value to the piezoelectric actuator, and
Extend it to the desired size. When the desired dimension is not reached even when the specified maximum voltage is applied to the piezoelectric actuator (the driven member is driven by the amount of extension), the voltage of the piezoelectric actuator is once completely reduced and contracted. At this time, the micrometer is rotated by the rotational force of the pulley having a constant torque fixed to the micrometer, and the piezoelectric actuator is pushed forward by the spindle portion of the micrometer by the amount of contraction of the piezoelectric actuator. Again, apply the specified voltage to the piezoelectric actuator and extend it to the desired size. Since it cannot extend in the direction of the spindle of the micrometer, it extends in the direction of the driven member,
In this way, the driven member is finely positioned and driven. By repeatedly applying and subtracting voltage to and from the piezoelectric actuator, the piezoelectric actuator and the micrometer and the pulley having a constant torque work to make the piezoelectric actuator a so-called scale insect. It is intended to perform fine movement with a long stroke by intermittently moving in one direction in units of μm.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, referring to the drawings, a specific embodiment will be described first (FIG. 7) to (FIG. 13). (Figure 7)
Is a fine positioning drive mechanism which is an embodiment of the present invention,
It is a side view when utilized for a precision stage. FIG. 8 is a plan view of FIG. 7. A surface plate 32 is provided with a stage 27, which is a driven member, slidably mounted on the upper surface of the surface plate 32. 28 and 29 are stage guide plates and screws 2
It is fixed to the surface plate 32 at 8-1 and 29-1. Reference numeral 1 is a piezoelectric actuator, and piezoelectric actuator guide members 23, 24, rollers 25, 26,
It has been received at. A micrometer receiver 7 is fixed to the upper surface of the surface plate 32 with a screw 7-2, and a micrometer 8 is fixed to the micrometer receiver 7 with a screw 7-1. A pulley 19 is fixed to the rotating portion 8b of the micrometer 8 with a screw 19-1. Pulley 19 has a weight 20
Is hung by the weight thread 20a, and a rotational force of a constant torque is given. A ball 22 is provided between the stage 27 and the piezoelectric actuator 1, and a ball 21 is provided between the piezoelectric actuator 1 and the spindle portion 8 a of the micrometer 8.
Is provided. (FIG. 9) is a cross-sectional view taken along line AB of (FIG. 7). The stage 27 is configured to be slidable by being guided by the stage guide plates 28 and 29 on the upper surface of the surface plate 32. FIG. 10 is a sectional view taken along line C-D of FIG. 7. Piezoelectric actuator guide members 23 and 24 are screws 2
It is fixed to the surface plate 32 at 3-1 and 24-1. Rollers 25, 2 so that the piezoelectric actuator 1 can slide lightly
Received in 6. FIG. 11 is a right side view of FIG. 7. When the torque of the pulley 19 is unnecessary, the weight 20 can be placed on the upper surface of the surface plate 32 as shown by the dotted line (FIG. 1).
2) is a sketch of the piezoelectric actuator guide member 23. (FIG. 13) is a cross-sectional view taken along the line EF of (FIG. 7).
The rollers 25 and 26 are received by ball bearings 23a and 24a.

The operation of the apparatus in which the fine positioning drive mechanism of the present invention is applied to the precision stage will be described below. Generally, this example is used under the field of view of a microscope. First, in (FIG. 7) (FIG. 8), turn the knob portion 8c of the micrometer 8 to move the ball 2
1. The stage 27 is driven through the piezoelectric actuator 1 and the ball 22. At this time, the drive is adjusted to the unit of the minimum scale 0 and 01 mm of the micrometer 8. Next, the piezoelectric actuator 1 is supplied with a power source (not shown). When a voltage is applied to the piezoelectric actuator 1 from the cord 3 and the connector 2, the piezoelectric element 1-1 expands. At this time, the screw cannot be extended in the direction of the spindle 8a of the micrometer 8 because it is a screw, and it is extended in the direction of the stage 27 that is a driven member, and the stage 27 is finely adjusted in units of μm. can do. In this way, the voltage is increased until the stage 27 can be adjusted to the desired dimensions. If the desired dimensions cannot be adjusted even after increasing the maximum voltage, reduce the voltage once. Then, the piezoelectric actuator 1 contracts, and the micrometer 8 is correspondingly retracted by the pulley 19 and the weight 20.
Is rotated with a constant torque and pressed against the piezoelectric actuator 1. Again, voltage is applied until the stage 27 can be adjusted to the desired dimensions. As in this operation, the voltage is repeatedly applied to the piezoelectric actuator 1 to finely drive the stage 27 to a desired size.

Next, one embodiment of the fine positioning drive mechanism of the present invention will be described with reference to an embodiment applied to a liquid micro-injection device (FIG. 14) (FIG. 15). This is (Fig. 7)
Instead of the stage 27 which is the driven member of (FIG. 8),
The device 15, which is a device for accurately injecting a small amount of liquid into a container (omitted) using the microsyringe 16, is a microsyringe receiver and is fixed to a surface plate 32 with a screw 15-1. It is fixed with a screw 15-2. (FIG. 7) Same as the operation described in (FIG. 8), the so-called, by adjusting the voltage of the constant width from the power source (omitted) to the piezoelectric actuator 1 from the cord 3 and the connector 2,
By causing the piezoelectric actuator 1 to perform an insect-like movement, the plunger 16-1 of the microsyringe is intermittently fed, and a certain amount of liquid can be accurately injected into the container (omitted).

Next, another embodiment of the fine positioning and parking mechanism of the present invention will be described, which is applied to a liquid microinjection device, as in the case of FIGS. 14 and 15. (Fig. 1
6) is a side view in which another embodiment of the fine positioning drive mechanism of the present invention is applied to a liquid microinjection device. (Fig. 1
7) shows a plan view of (FIG. 16). (Figure 14) (Figure 1
The portion of the micrometer 8 and the pulley 19 shown in the embodiment 5) is replaced with a fan-shaped cam 34. A pair of fan-shaped cam receivers 35 are fixed to the upper surface of the surface plate 32 with screws 35-1, and the fan-shaped cams 34 are rotatably held by pins 36. A roller 1a is rotatably held on the end surface of the piezoelectric actuator 1 by a pair of roller receivers 1c. FIG. 18 shows a plan view of the fan-shaped cam 34. A pin 36 is fitted in the rotation hole 34-1 so as to be rotatable. When the fan-shaped cam 34 rotates counterclockwise by its own weight, the fan-shaped cam outer circumference 34a pushes the piezoelectric actuator 1 by a cam displacement amount e corresponding to the rotation angle. Next, the operation will be described. First, in the state of (FIG. 16), when a constant voltage is applied to the piezoelectric element 1-1 of the piezoelectric actuator 1, expansion corresponding to the applied voltage occurs. Since the roller 1a and the outer periphery 34a of the fan-shaped cam 34 are in contact with each other and cannot extend in the direction of the fan-shaped cam 34, they extend in the direction of the plunger 16-1 and push the plunger 16-1 by the amount of extension. Become. A liquid corresponding to the pushing amount of the plunger 16-1 can be injected. (The voltage applied in advance and the extension of the piezoelectric element 1-1, that is, the driving amount of the plunger 16-1 are determined beforehand). Next, when the voltage applied to the piezoelectric element 1-1 of the piezoelectric actuator 1 is completely reduced, the piezoelectric element 1
-1 contracts by a certain amount. Then, the fan-shaped cam 34 rotates by its own weight and pushes the piezoelectric actuator 1 by the contraction amount. Thus, by repeatedly applying the width between the upper limit and the lower limit of the voltage, it is possible to sequentially inject a fixed amount of liquid.

[0010]

EFFECTS OF THE INVENTION By causing the piezoelectric actuator to make a worm-like movement, it is possible to form a fine positioning drive mechanism in a unit of μm having a long stroke even with a piezoelectric actuator having a short total length. The overall length of the piezoelectric actuator is short and the cost is as low as possible.

[Brief description of drawings]

FIG. 1 is a sketch of a piezoelectric actuator.

FIG. 2 is a voltage-displacement characteristic diagram of the piezoelectric actuator.

FIG. 3 is a plan view of a stage having a conventional fine positioning mechanism.

FIG. 4 is a side view of (FIG. 3).

5 is a cross-sectional view taken along line AB of FIG.

FIG. 6 is a CD cross-sectional view of (FIG. 3).

FIG. 7 is a side view of an apparatus in which a fine positioning drive mechanism according to an embodiment of the present invention is used for a precision stage.

FIG. 8 is a plan view of (FIG. 7).

9 is a cross-sectional view taken along the line AB of FIG.

FIG. 10 is a sectional view taken along line CD of FIG.

FIG. 11 is a right side view of (FIG. 7).

FIG. 12 is a sketch of a piezoelectric actuator guide member.

13 is a cross-sectional view taken along line EF of FIG.

FIG. 14 is a side view when an embodiment of the fine positioning drive mechanism of the present invention is applied to a trace amount liquid injection device.

FIG. 15 is a plan view of (FIG. 14).

FIG. 16 is a side view when another embodiment of the fine positioning drive mechanism of the present invention is applied to a trace amount liquid injection device.

FIG. 17 is a plan view of (FIG. 16).

FIG. 18 is a plan view of the fan-shaped cam 34.

[Explanation of symbols]

1 = Piezoelectric actuator 2 = Connector
3 = code 5 = slide stage 6 = substrate
7 = Micrometer receiver 8 = Micrometer 9 = Piezoelectric actuator receiver
15 = Microsyringe receiver 16 =
Microsyringe 18 = Tube 19 = Pulley 20 = Weight 20
-A = weight thread 21, 22 = ball 23, 24 = piezoelectric actuator guide member 23a, 24a = ball bearing 25, 26 = roller 27 = stage 28, 29 = stage guide plate 32 = surface plate
34 = fan-shaped cam 35 = fan-shaped cam receiver 36 = pin

Claims (2)

[Claims] 1. A fine positioning drive mechanism including a piezoelectric actuator guide member, a piezoelectric actuator, a micrometer, and a pulley for rotating the micrometer with a constant torque. 2. A fine positioning drive mechanism comprising a piezoelectric actuator guide member, a piezoelectric actuator, and a rotatable fan-shaped cam.