JP2002263979A - Feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a feeding device with simple structure and to provide an increased life. SOLUTION: The feeding device to move an object 31 to be conveyed in a predetermined direction comprises a stretching and displacing first piezoelectric element 12; a first drive part 15a to apply a press force on the object 31 to be conveyed, a second piezoelectric element 22 stretching and displacing in a direction approximately orthogonal to the stretching direction of the first piezoelectric element 12; and a second drive part 15b to apply a press force or a tensile force on the first drive part 15a. With the first piezoelectric element 22 stretched, the second piezoelectric element 22 is retracted, and the object 31 to be conveyed is moved in the retracting direction of the second piezoelectric element 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feeder used for a linear transfer device, an XY table, a rotary table and the like.

[0002]

2. Description of the Related Art Conventionally, when an electric field is applied in the same direction as the polarization direction of a piezoelectric body, a thickness-longitudinal displacement (33 mode displacement) is generated in the piezoelectric body, and a direction perpendicular to the polarization direction of the piezoelectric body is generated. By applying an electric field to the
It is known that a sliding displacement (15-mode displacement) occurs, and a piezoelectric element (3
Various feeders using a piezoelectric element (15 mode element) using a 15 mode displacement and a 3 mode element have been proposed.

For example, Japanese Unexamined Patent Publication No. Hei 4-221792 discloses a feeder configured to support a movable body with a leg composed of one 33-mode element and one 15-mode element. . The leg has a configuration in which a 33-mode element is fixed to the movable body and a 15-mode element is grounded to the fixed body. The operation of the feeder using two legs (a first leg and a second leg) is roughly as follows.

[0004] First, the 15-mode element of the first leg is sheared so that the ground contact surface is displaced in the traveling direction of the movable body, and the 33-mode element is extended to bring the first leg into contact with the ground. At this time, the second leg is left floating from the ground contact surface. This state is referred to as a first step. Next, when the direction of the shear deformation of the 15 mode element of the first leg is reversed, the ground position of the 15 mode element does not change, so that the 33 mode element in the first leg advances by the amount of deformation of the 15 mode element. Move in the direction. That is, the movable body moves in the traveling direction by the amount of deformation of the 15-mode element. During this time, the 15-mode element of the second leg is sheared so that the ground contact surface moves in the traveling direction. This step is the second step.

In a third step, the 33 mode element of the second leg is extended to ground the second leg, while the third mode element of the first leg is grounded.
The three-mode element is contracted so that the 15-mode element of the first leg is lifted from the ground plane. In this way, the second leg is in contact with the ground and supports the movable body. Next, in the fourth step, the movable body is moved in the traveling direction by the amount of deformation of the 15-mode element by reversing the direction of the shear deformation of the 15-mode element of the second leg in the same manner as in the second step. In the meantime, the 15-mode element of the first leg is caused to undergo a shear deformation so that the ground contact surface moves in the traveling direction.

When the first leg is grounded after the fourth step, and the second leg is lifted from the ground,
This is the same as the state after the first step. That is, by repeating the first to fourth steps for the first leg and the second leg after the fourth step, the movable body can be moved by a predetermined distance.

[0007]

However, since the polarization direction of the 15-mode device is perpendicular to the direction of application of the driving electric field, there is a problem in increasing the magnitude of the driving electric field.
Further, the polarization may be extinguished by the driving electric field.
When depolarization occurs in the 15-mode element, repolarization cannot be performed, and there has been a problem that the feeder itself cannot be used.

Further, the manufacturing process of the 15-mode device is complicated, for example, the electrode used for polarization must be removed after polarization to newly provide a driving electrode. If the length is long, it becomes necessary to apply a larger driving voltage, and there is a problem that the safety at the time of using the feeding device is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems of the prior art, and has as its object to provide a feeder having a simple structure and a long life.

[0010]

That is, according to the present invention,
A feed device for applying a predetermined force to a transported object to move the transported object in a predetermined direction, comprising a first piezoelectric element that expands and contracts, and is provided to the transported object by extension of the first piezoelectric element. A first driving unit that applies a pressing force to the first piezoelectric element, and a second piezoelectric element that expands and contracts in a direction substantially perpendicular to the expansion and contraction direction of the first piezoelectric element. A second driving unit for applying a pressing force or a pulling force to the first driving unit, and the second piezoelectric element is expanded and contracted in a state where the first piezoelectric element is expanded. A feeder is provided, which moves a carrier in a direction in which the second piezoelectric element expands and contracts.

In such a feeder, since the first piezoelectric element and the second piezoelectric element use expansion and contraction displacement (thickness-longitudinal displacement), the polarization does not disappear by driving the piezoelectric elements. Thus, the service life of the feeder can be extended. Further, in the feeder of the present invention, since the transported body can be moved by driving at least two piezoelectric elements, the control is easy.

By using a plurality of feed mechanisms including the first drive unit and the second drive unit used in the feed device of the present invention, the transported object can be moved in a two-dimensional direction or can be moved at a predetermined angle. Rotation becomes possible. For example, when the X direction and the Y direction orthogonal to each other are determined, a predetermined number of feed mechanisms are arranged so that the expansion and contraction direction of the second piezoelectric element matches the X direction, and If a predetermined number of expansion and contraction directions are arranged so as to match the Y direction, the expansion and contraction direction of the second piezoelectric element becomes the moving direction of the carrier, so that the X direction or the Y direction
The transported object can be moved in the direction.

Further, a plurality of feed mechanisms are arranged on a concentric circle so that the direction of expansion and contraction of the second piezoelectric element coincides with the normal direction of the concentric circle. When the second piezoelectric element is expanded and contracted in the clockwise direction or the counterclockwise direction in the concentric circle in a state where the element is extended, a rotational force can be applied to the transported object, and the transported It is possible to rotate the body by a predetermined angle.

In such a feeder, the first drive unit and the second drive unit may each have a structure composed of only a piezoelectric element, but preferably have the following structure. That is, the first drive unit has a first support member attached to a fixed base and a contact member that comes into contact with or separates from the transported object, and the second drive unit has a base. As a structure having a second support member fixed to the
Is arranged between the contact member and the first support member, and the contact member is expanded or contracted so as to press or separate from the transported object, and the second piezoelectric element is moved to the second support member. When the first support member is expanded and contracted so as to be pulled, separated, or pressed against the first support member in a direction perpendicular to the direction of expansion and contraction of the first piezoelectric element, a large amount of displacement of the first drive unit can be obtained. In addition, the second piezoelectric element does not damage the first piezoelectric element, so that the life of the device is prolonged and the reliability is improved.

[0015] It is also preferable to provide a third drive section opposed to the second drive section with the first drive section interposed therebetween. In this case, the third piezoelectric element provided in the third drive section is substantially perpendicular to the direction of expansion and contraction of the first piezoelectric element, and
Expands and contracts in a direction substantially in line with the expansion and contraction direction of the piezoelectric element, and applies a pressing force to the first drive unit by extension. Then, the third piezoelectric element is contracted / expanded in synchronization with the extension / reduction of the second piezoelectric element, that is, the first driving section is driven more smoothly by performing the expansion and contraction in opposite directions. Becomes possible.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. The feeder of the present invention performs a predetermined motion by combining at least two piezoelectric elements using the thickness-longitudinal displacement (33 mode displacement) of the piezoelectric body. The material (piezoelectric ceramic, polymer piezoelectric, single crystal piezoelectric, etc.) and form (plate, block, single plate, laminated body, etc.) of the piezoelectric material used are not limited, but practically A laminated piezoelectric element made of piezoelectric ceramics is preferably used.

The laminated piezoelectric element includes a so-called adhesive type formed by sequentially laminating a plate-like piezoelectric body having an electrode film formed on the front and back principal surfaces with an adhesive while interposing a metal plate. There is an integrated fired type produced by stacking and integrating green sheets on which electrodes are printed, and preferably, for example, as shown in FIG.
An integrated firing type laminated piezoelectric element 97a in which the thickness of one piezoelectric body 95 is reduced and the internal electrodes 96 are alternately stacked in several layers
Is preferably used. The internal electrodes 96 alternate with the external electrodes 9
8, the polarization of the piezoelectric body 95 is not extinguished by the application of the driving voltage because it is paired and used for both polarization and driving.

The multilayer piezoelectric element 97a shown in FIG. 10A is generally called a multilayer capacitor type. In addition to this, as shown in FIG. The electrodes 96 are exposed on the side surfaces of the element, and an insulating layer 99 is formed every other layer, and the internal electrodes 96 are formed every other layer.
Is connected to an external electrode 98, and a stress relief layer 94 is provided on a portion of the piezoelectric element 95 where the internal electrode 96 does not overlap in the stacking direction of the piezoelectric body 95, as shown in FIG. A formed multi-layer piezoelectric element 97c called a slit type is known, and in the present invention, the form of the multi-layer piezoelectric element used is not limited.

FIG. 1 is an explanatory view showing an embodiment of a feeder of the present invention using such a laminated piezoelectric element. The feed device shown in FIG. 1 moves a transported body 31 by a feed mechanism 10 along a guide 32 extending in the X direction. The feed mechanism 10 is provided between the guide 32 and a base 33 fixed at a predetermined distance, and includes a first drive unit 15a and a second drive unit 15b.

The first drive section 15a includes a first contact member 11 that contacts or separates from the transported body 31, a first support member 13 attached to the base 33, and a first contact member 11
Piezoelectric element 1 provided between the first piezoelectric member 1 and the first support member 13
2, the direction of expansion and contraction of the first piezoelectric element 12, that is, the thickness-longitudinal displacement direction is the Y direction. The second driving unit 15b includes a second contact member 21 joined to the first support member 13, a second support member 23 fixed to the base 33, the second contact member 21 and the second support member. A second piezoelectric element provided between the first piezoelectric element and the second piezoelectric element; and a second piezoelectric element provided between the first piezoelectric element and the second piezoelectric element.

FIG. 2 is an explanatory view showing an example of a driving mode of the feed mechanism 10. In FIG.
And only the second piezoelectric element 22 and the transported body 31 are denoted by reference numerals. The state shown in FIG. 2A, that is, neither the first piezoelectric element 12 nor the second piezoelectric element 22 is driven, and the first contact member 11 is spaced apart from the transported body 31 by a small distance. Let the state be the initial state. FIG.
In each figure of (e), the position P1 is the first driving unit 15a.
In the X direction are shown.

From the initial state shown in FIG. 2A, first, the first piezoelectric element 12 is extended to bring the first contact member 11 into contact with the conveyed body 31 (this contact position is indicated by a point S). Shown), and the first driving unit 15a operates the transported body 3 with a predetermined force.
1 is pressed (FIG. 2B). Next, with the first piezoelectric element 12 extended, the second piezoelectric element 22
Is extended, and a predetermined force in the X direction is pressed against the first drive unit 15a, the pressing force causes the first drive unit 15a to rotate or shear from the joint surface between the first support member 13 and the base 33 as a starting point. The first contact member 11 moves to the right in the X direction (hereinafter referred to as the “+ X direction”) (FIG. 2).
(C)). At this time, the first contact member 11 and the transferred object 31
The transported object 31 also moves in the + X direction along with the movement of the first contact member 11 due to the frictional force generated by the pressing force between the first contact member 11 and the second contact member 11.

Subsequently, the first piezoelectric element 12 is contracted while the second piezoelectric element 22 remains extended. As a result, the transferred object 31 and the first contact member 11 are separated from each other, and the transferred object 3
1 is maintained in a state of having moved a predetermined distance in the + X direction (FIG. 2D). Further, when the second piezoelectric element 22 is contracted, the feed mechanism 10 returns to the state shown in FIG. 2A (FIG. 2E). By repeating such an operation of the feed mechanism 10 a predetermined number of times, the transported object 31 in FIG.
Can be moved from the position shown by the solid line until the right end thereof reaches the position E2.

When shifting from the state shown in FIG. 2D to the state shown in FIG. 2E, the first contact member 11 has such an extent that the transported body 31 is not returned to the original position. It may be in contact with the transported body 31 by frictional force. In other words, in the initial state shown in FIG. 2A, the first contact member 11 is in a state where a frictional force is generated such that the transferred body 31 does not move even if the position of the first contact member 11 moves. May be in contact with the transported body 31.

FIG. 3 is an explanatory view showing another example of the drive mode of the feed mechanism 10, and is shown in the same format as FIG. The state shown in FIGS. 3A and 3B is the same as the state previously shown in FIGS. 2A and 2B,
From the state of FIG. 3B, when the second piezoelectric element 22 is contracted while the first piezoelectric element 12 is extended and the first driving section 15a is pulled toward the second driving section 15b, this tensile force is reduced to the second driving section 15b. The first driving unit 15a acts so as to rotate or shear from the joint surface between the first support member 13 and the base 33, and the position of the first contact member 11 is set to the left side in the X direction (hereinafter referred to as “−X direction”). ) (FIG. 3 (c)). At this time, the transported object 31 also moves in the −X direction along with the movement of the first contact member 11 due to the frictional force generated by the pressing force between the first contact member 11 and the transported body 31.

Subsequently, the first piezoelectric element 12 is contracted while the second piezoelectric element 22 is kept contracted. As a result, the transported body 31 and the first contact member 11 are separated from each other, and the transported body 31
Are maintained in a state where they have moved a predetermined distance in the −X direction (FIG. 3D). When the second piezoelectric element 22 is further extended and returned to the original length, the feed mechanism 10 returns to the state shown in FIG. 3A (FIG. 3E). By performing such driving of the feed mechanism 10 a predetermined number of times, in FIG. 1, the left end of the transported body 31 in the X direction from the position indicated by the solid line is located at the position E.
It can be moved until it reaches 1.

By combining the driving modes shown in FIGS. 2 and 3, it is possible to move the transported body 31 at a higher speed. For example, when the transported body 31 is moved at a high speed in the + X direction, first, FIG. 2 (a) → FIG. 2 (b) → FIG.
(C) → Drive the first drive unit 15a and the second drive unit 15b in the order described earlier in the order of FIG. 2 (d). Then, while the first piezoelectric element 12 is contracted so as to shift from the state of FIG. 2D to the state of FIG.
2 is contracted, and then the first piezoelectric element 12 is extended so that the state shown in FIG. 3C is obtained (FIG. 2D → FIG. 3).
(D) → FIG. 3 (c)). Further, the second piezoelectric element 22 is extended while the first piezoelectric element 12 is extended so that the state of FIG. 3C is changed to the state of FIG.
(C) → FIG. 2 (c). According to such a driving mode, the moving amount of the first contact member 11 in the + X direction can be increased, and the moving speed of the transported body 31 can be increased. When stopping the movement of the transported body 31,
The first drive unit 15a and the second drive unit 15b may be driven in the order of FIG. 2 (c) → FIG. 2 (d) → FIG. 2 (e).

Similarly, when the transported body 31 is moved at a high speed in the -X direction, FIG. 3 (a) → FIG. 3 (b) → FIG.
(C) → FIG. 3 (d) → FIG. 2 (d) → FIG. 2 (c) → FIG.
(C) → FIG. 3 (d) → FIG. 3 (e).
5a and the second drive unit 15b may be driven.

Since the feed mechanism 10 drives the first piezoelectric element 12 and the second piezoelectric element 22 using the thickness-longitudinal displacement as described above, the feed mechanism 10 applies the electric field in the direction opposite to the polarization direction to perform the polarization. Even if disappears or the direction of polarization is reversed, repolarization is possible, and the device life is prolonged. Further, since the feed mechanism 10 can be driven by controlling two piezoelectric elements, the control is easy.

As described above, the first abutting member 11 is a member that abuts on the transported body 31 and generates a predetermined frictional force with the transported body 31. It is preferable to use a material that generates an appropriate frictional force. For example, a metal material such as a super-hard or hard stainless steel or an engineering ceramic material such as silicon carbide (SiC) or silicon nitride (Si ₃ N ₄ ) is preferable. Used. The first support member 13 is a material that is deformed by a pressing force received from the second drive unit 15b, and must have a predetermined rigidity. For example, a metal material such as stainless steel is preferably used. Can be

Since the second contact member 21 needs to transmit the displacement generated in the second piezoelectric element 22 to the first drive portion 15a without attenuating the material, the second contact member 21 has a predetermined hardness and rigidity and is hardly deformed. It is preferable to use, for example,
The same hard metal material or engineering ceramic material as the first contact member 11 is used. For bonding the second contact member 21 and the first drive unit 15a, an adhesive having a high adhesive strength such as an epoxy-based adhesive is suitably used. At this time, the displacement generated in the second piezoelectric element 22 by the adhesive is used. It is preferable to adjust the thickness and the hardness so that is not absorbed. Note that the second contact member 21 is not always necessary, and one of the end faces in the expansion and contraction direction of the second piezoelectric element 22 may be directly joined to the first drive unit 15a.

The second support member 23 needs to be immovable so that most of the force generated by the displacement of the second piezoelectric element 22 is applied to the first drive unit 15a. For this reason the second
The support member 23 is preferably designed to have sufficient strength and hardness using a hard metal material or the like. Base 33
Needs to have sufficient rigidity so as not to bend when the second piezoelectric element 22 is driven. For example, a hard metal member is suitably used. The first support member 13 or the second support member 23 and the base 33 can be joined by a method using an adhesive, a method of screwing, or the like.

The first piezoelectric element 12 has only to press the first contact member 11 against the transported object 31 with a predetermined pressure.
It does not require an extremely large displacement. On the other hand, the amount of displacement of the second piezoelectric element 22 determines the amount of deformation of the first driving unit 15a and the amount of movement of the object 31. Therefore, in order to realize high-speed movement of the object 31. Is
It is preferable to use an element having a large displacement.

When a predetermined pressing force is applied to the first driving unit 15a from the second driving unit 15b by displacing the second piezoelectric element 22 by a predetermined amount, the pressing force is applied to the first supporting member 13 or the first driving unit 15a. It may be applied to either the first piezoelectric element 12 or the first contact member 11. However, if this pressing force is applied to the first piezoelectric element 12, there is a possibility that the first piezoelectric element 12 may fail.
When this pressing force is applied, the amount of displacement of the first contact member 11 becomes equal to the amount of displacement of the second piezoelectric element 22. It is necessary to use a large displacement.

On the other hand, when the pressing force from the second drive section 15b is applied to the first support member 13, the joint between the first support member 13 and the base 33 becomes the starting point and the first support Since the member 13 is rotated or sheared, the first contact member 11 moves as a result of being displaced and enlarged.
One way to increase the displacement enlargement amount is to increase the length of the first support member 13 in the Y direction, which can be as long as possible under actual use conditions.

Another method for increasing the displacement enlargement amount is as follows.
In this method, the pressing force from the driving unit 15b is applied to the vicinity of the joint between the first support member 13 and the base 33. In this case, a large pressing force is required to deform the first contact member 11. And On the other hand, the pressing force from the second drive unit 15b is applied to the first piezoelectric element 1 in the first support member 13.
2, the amount of movement of the first contact member 11 can be increased with an appropriate pressing force.

Here, for example, like the first support member 13a shown in FIG. 4 (a), a constricted portion between the portion receiving the pressing force from the second driving portion 15b and the joint portion with the base 33. Is provided, the deformation due to the pressing force from the second driving unit 15b is facilitated. Further, the first support member 1 shown in FIG.
3b, the joint area with the base 33 is reduced so that the joint with the base 33 becomes a fulcrum.
Deformation due to the pressing force from the driving unit 15b is facilitated.

Next, an explanatory view showing another embodiment of the feeder of the present invention is shown in FIG. The feeding device shown in FIG.
Is different from the feeding device shown in FIG. 1 in that the second driving unit 1 having the second contact member 21a not joined to the first driving unit 15a
5b ', and the base 33 is fitted to the guide 32 so that the clamp 3 is slidable in the longitudinal direction of the guide 32.
4 and the first contact member 11 contacts the guide 32 at two points. The second contact member 21a is
It is preferable that the first driving unit 15a be in contact with the first driving unit 15a with a pressing force that does not deform the driving unit 15a because the displacement amount and the generated force of the second piezoelectric element 22 can be effectively used. However, from the viewpoint of the driving principle, the second contact member 21a
May be separated from the first drive unit 15a by a distance shorter than the displacement amount of the second piezoelectric element 22.

The feed mechanism 10 'including the first drive section 15a and the second drive section 15b' can be driven by the drive mode shown in FIG. 2, similarly to the feed mechanism 10 shown in FIG. When the feed mechanism 10 ′ is driven according to the drive mode shown in FIG. 2, the guide 32 is fixed and the clamp 3
4 is movable, the feed mechanism 10 ′ moves in the −X direction together with the base 33 and the clamp 34, and conversely, when the clamp 34 and the base 33 are fixed and the guide 32 is movable, 32 moves in the + X direction.

However, the drive mechanism shown in FIG. 3 cannot be used for the feed mechanism 10 'because the second contact member 21' is not joined to the first drive section 15a. Therefore, when the guide 32 is fixed and the clamp 34 is movable, the feed mechanism 10 ′ is moved in the + X direction together with the base 33 and the clamp 34, and conversely, the clamp 34 and the base 33 are fixed and the guide 32 is fixed. In order to move the guide 32 in the −X direction when is movable, the driving mode shown in FIG. 6 is used.

FIG. 6 is an explanatory view showing an embodiment in which the guide 32 is moved in the -X direction when the position of the feed mechanism 10 'is fixed. The position P1 shown in each figure of FIG.
FIG. 6A shows an X direction arrangement position (coordinates) of the first drive unit 15a in a state where the first drive unit 15a is not driven. FIG. 6A shows an initial state in which the feed mechanism 10 'is not operated. Is shown.

First, from the initial state shown in FIG. 6A, the second piezoelectric element 22 in the second drive mechanism 15b 'is extended to deform the first drive section 15a so as to tilt it to the + X side. (FIG. 6 (b)). Then, the first piezoelectric element 12
Is extended, the first contact member 11 is brought into contact with the guide 32, a predetermined pressing force is applied to the guide 32, and a predetermined frictional force is generated between the first contact member 11 and the guide 32. (FIG. 6C). Note that a point S ′ shown in FIG. 6C indicates a contact position between the first contact member 11 and the guide 32. Subsequently, when the second piezoelectric element 22 is contracted from the state shown in FIG. 6C, the first drive unit 15a attempts to return to the original posture, and at this time, the position of the point S 'is changed to the position P1.
It moves in the -X direction so as to come up (FIG. 6D). Further, when the first piezoelectric element 12 is contracted, the feed mechanism 10 'returns to the initial state shown in FIG. 6A (FIG. 6E).

Like the feed mechanism 10 ', the second contact member 2
When 1a is not joined to the first drive unit 15a,
By performing the expansion and contraction of the second piezoelectric element 22 steeply using a rectangular wave voltage, an impact force is applied to the first drive unit 15a, that is, a force that flips the first drive unit 15a in the + X direction is applied. Thereby, the first driving unit 15a can be deformed so as to fall in the + X direction. In this case, as compared with the case where the feed mechanism 10 ′ is driven in a state where the second contact member 21a is in contact with the first drive unit 15a, the first
The driving section 15a can be greatly deformed.

In the feed mechanism 10 ′, the first piezoelectric element 12 can also be driven so as to apply an impact force to the guide 32. As a result of driving the first piezoelectric element 12 and the second piezoelectric element 22, if the impact force applied from the first piezoelectric element 12 to the guide 32 has a component in the X direction, the guide 32 and the feed mechanism 10 'are used. Relative movement is possible. Note that the above-described feed mechanism 10 can also use a driving method that sharply deforms the first piezoelectric element 12.

Next, FIG. 7 is an explanatory view showing still another embodiment of the feeder of the present invention. The feed device shown in FIG. 7 includes a first driving unit 1 that constitutes the feed mechanism 10 shown in FIG.
5a and the second driving unit 15b, the first driving unit 15
a third drive unit 15 opposed to the second drive unit 15b across
c) is provided. The third driving unit 15c is configured to expand and contract in the X direction with a third contact member 21 ′ joined to the first driving unit 15a to apply a predetermined pressing force to the first driving unit 15a. It comprises an element 22 'and a third support member 23' for holding the third piezoelectric element 22 '.

Such a driving method of the feed mechanism 10 ″ may be used in combination with the driving methods shown in FIGS. 2 and 3. That is, the third piezoelectric element 22 'is contracted in synchronization with the operation of extending the second piezoelectric element 22, while the third piezoelectric element 22' is extended in synchronization with the operation of contracting the second piezoelectric element 22. Then, the first driving unit 15a is set to + X
It can be deformed so that it can easily fall in any of the direction and the -X direction.

As described above, the feed mechanism used in the feeder of the present invention basically includes a transport mechanism that moves the transport object in the expansion and contraction direction of the second piezoelectric element provided in the second drive unit. It is driven to apply a predetermined force to the body. Hereinafter, an embodiment of a feeder including a plurality of feed mechanisms 10 will be described with reference to the drawings, using the feed mechanism 10 as an example. Of course, in the embodiment of the feeding device described below, it is possible to use feeding mechanisms 10 ′ and 10 ″ instead of the feeding mechanism 10.

FIG. 8 is a plan view showing an XY table 40 in which eight feed mechanisms 10 (hereinafter referred to as "feed mechanisms 10a to 10h") are arranged at the vertices of a square and the midpoint of each side. . The XY table 40 is disposed on the upper surface of the fixed base 41 such that the expansion and contraction directions of the second piezoelectric elements 22 match the X direction for the feed mechanisms 10a to 10d,
The feed mechanisms 10e to 10h are arranged such that the expansion and contraction direction of the second piezoelectric element 22 matches the Y direction, and have a structure in which the slide table 42 is mounted on the feed mechanisms 10a to 10h.

Therefore, in the XY table 40,
It is possible to move the slide table 42 in the X direction by driving the feed mechanisms 10a to 10d and not driving the feed mechanisms 10e to 10h during this time. Conversely, the feed mechanisms 10e to 10h are driven. During this time, the slide table 42 can be moved in the Y direction by not driving the feed mechanisms 10a to 10d. When the feed mechanisms 10a to 10h are attached to the lower surface of the slide table 42 and the first contact member 11 is configured to be in contact with the base 41, the slide table 42 can be configured to run on its own.

FIG. 9 shows three feeding mechanisms 10 (hereinafter referred to as "feeding mechanisms 10i to 10k") such that the direction of expansion and contraction of the second piezoelectric element 22 on the concentric circle M coincides with the normal direction of the concentric circle M. FIG. 3 is a plan view showing a rotary feeder 50 arranged in the first embodiment. In the rotary feeder 50, feed mechanisms 10i to 10k are provided on the upper surface of a fixed base 51.
It has a structure in which the turntable 52 is arranged on 0i to 10k.

In the rotary feeder 50, the feed mechanisms 10i to 10i
10k simultaneously with the second piezoelectric element with the first piezoelectric element extended.
By driving the piezoelectric element 22 so as to extend, the rotary table 52 can be rotated clockwise by a predetermined angle. Conversely, by driving the second piezoelectric element to contract while the first piezoelectric element is extended, the rotary table 52 can be rotated in a counterclockwise direction, and the feed mechanisms 10i to 10k can be rotated. By performing the driving continuously, it can be used as a rotary motor. When the feed mechanisms 10i to 10k are attached to the lower surface of the turntable 52 and the first contact member 11 is brought into contact with the base 51, a self-propelled rotary device can be obtained.

The embodiment of the feeder according to the present invention has been described above, but the present invention is not limited to the above embodiment. For example, when at least two feed mechanisms 10 are arranged in the X direction in the feed device shown in FIG. 1 and the driving mode shown in FIG. 2 is used, one feed mechanism 10 is changed from FIG. When the state is changed to the state shown in FIG. 2E, the state of the other feed mechanism 10 is changed from the state shown in FIG. 2B to the state shown in FIG. Thus, the transported body 31 can be moved at a higher speed.

In the XY table 40 shown in FIG. 8, the feed mechanism 10 for moving in the X direction is arranged at three positions supporting the slide table 42 at three points. It is possible to adopt a form in which the feed mechanism 10 for moving in the Y direction is arranged at three positions supporting three points. Further, in the rotary feeder 50 shown in FIG.
Is used only for driving to rotate clockwise, and another three feeds for rotating the turntable 52 counterclockwise to a position symmetrical with the position of the feed mechanisms 10i to 10k with respect to the rotation center. It is also possible to provide a mechanism 10. Thus, not only the feed mechanism 10 but also the feed mechanism 10 '
By combining a plurality of 10 ″, it is also possible to realize a feeder that can perform more complicated movement, for example, both planar slide movement and rotational movement, by the transported body.

[0054]

As described above, according to the feeder of the present invention, since the thickness-longitudinal displacement of the piezoelectric element is used, the electric field is applied in the direction opposite to the polarization direction, and the polarization disappears or the direction of the polarization. Is reversed, repolarization is possible. Thus, the life of the device is prolonged and the reliability is enhanced. Further, since the feed mechanism uses two piezoelectric elements as a minimum unit, control is easy. Further, by manufacturing a laminated piezoelectric element to be used by an integral firing method using a green sheet, it is possible to improve productivity.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a feeder of the present invention.

FIG. 2 is an explanatory view showing one driving mode of the feeder shown in FIG. 1;

FIG. 3 is an explanatory diagram showing another driving mode of the feeding device shown in FIG. 1;

FIG. 4 is an explanatory view showing another embodiment of the feeder of the present invention.

FIG. 5 is an explanatory view showing still another embodiment of the feeder of the present invention.

FIG. 6 is an explanatory diagram showing one driving mode of the feeding device shown in FIG. 5;

FIG. 7 is an explanatory view showing still another embodiment of the feeder of the present invention.

FIG. 8 is a plan view showing the structure of an XY table using a feed mechanism used in the feed device of the present invention.

FIG. 9 is a plan view showing a structure of a rotary feeder using a feed mechanism used in the feeder of the present invention.

FIG. 10 is a cross-sectional view showing one embodiment of a piezoelectric element suitably used for the feeder of the present invention.

[Explanation of symbols]

 10.10a to 10k; feed mechanism 10 '/ 10' '; feed mechanism 11; first contact member 12; first piezoelectric element 13.13a / 13b; first support member 15a; first drive unit 15b; Drive unit 15c; third drive unit 21 · 21 ′; second contact member 22; second piezoelectric element 23; second support member 31; transported body 32; guide 33; base 34; clamp 40; Table 41; base 42; slide table 50; rotary feeder 51; base 52; rotary table 94; stress relief layer 95; piezoelectric body 96; internal electrodes 97a to 97c; laminated piezoelectric element 98; layer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masayuki Watanabe 2-4-2 Daisaku, Sakura City, Chiba Prefecture Inside the Cement Co., Ltd. (72) Ryoichi Fukunaga 2-4-2 Daisaku, Sakura City, Chiba Pacific Within Cement Co., Ltd. (72) Inventor Junko Seki 2-4-2 Daisaku, Sakura-shi, Chiba Pref. Pacific Ocean Cement Co., Ltd.

Claims (5)

[Claims] 1. A feeding device for applying a predetermined force to a transported object to move the transported object in a predetermined direction, comprising a first piezoelectric element that expands and contracts and expands the first piezoelectric element. The pressing force is applied to the transferred object by
And a second piezoelectric element that expands and contracts in a direction substantially perpendicular to the direction in which the first piezoelectric element expands and contracts. And a second driving unit for applying a pressing force or a tensile force, wherein the second piezoelectric element is expanded and contracted in a state where the first piezoelectric element is expanded, so that the object to be conveyed is moved to the second piezoelectric element. A feeding device for moving an element in the direction of expansion and contraction. 2. A feed mechanism comprising a first drive unit and a second drive unit is provided with a second piezoelectric device so that a transported object can be moved in an X direction and a Y direction orthogonal to each other. A predetermined number of elements are arranged so that expansion and contraction directions of the elements coincide with the X direction, and a predetermined number are arranged so that expansion and contraction directions of the second piezoelectric elements coincide with the Y direction. 2. The feeding device according to 1. 3. A plurality of feed mechanisms including the first drive unit and the second drive unit are arranged on a concentric circle such that the direction of expansion and contraction of a second piezoelectric element coincides with the normal direction of the concentric circle. When the first piezoelectric elements of the plurality of feed mechanisms are extended, the second piezoelectric element is conveyed by expanding and contracting in the clockwise direction or the counterclockwise direction in the concentric circle. The feeding device according to claim 1, wherein the body is rotated by a predetermined angle. 4. The first drive unit includes: a first support member attached to a fixed base; and a contact member that is in contact with or separated from a transported body. A second driving unit having a second support member fixed to the base, wherein the first piezoelectric element is located between the contact member and the first support member; The contact member expands and contracts so as to press or separate from the transferred object, and the second piezoelectric element is joined to the second support member,
4. The first piezoelectric element expands and contracts so as to be pulled, separated or pressed against the first support member in a direction orthogonal to the expansion and contraction direction of the first piezoelectric element. The feeding device according to item 1. 5. A device according to claim 1, further comprising: a third driving unit that faces the second driving unit with the first driving unit interposed therebetween, wherein the third driving unit is configured to move in a direction in which the first piezoelectric element expands and contracts. A third piezoelectric element that extends and contracts in a direction that is substantially orthogonal to and substantially in line with the expansion and contraction direction of the second piezoelectric element and applies a pressing force to the first drive unit by extension. The third piezoelectric element in synchronization with the extension / reduction of the second piezoelectric element.
The feed device according to any one of claims 1 to 4, wherein the piezoelectric element is reduced / expanded.