JPS62145309A - Precise feeding device - Google Patents

Abstract

PURPOSE:To feed a member to be fed axially precisely at intervals of fine distance by providing a piezoelectric element which vibrates a guide bar for guiding the feed member axially to one end of the guide bar. CONSTITUTION:The 2nd piezoelectric element 35 on a carriage side is driven before the 1st piezoelectric element 25 on a guide-bar side is driven, so that clamping pieces 31 and 32 are so displaced as to come closer to each other. Consequently, a carriage 20 moves by fine distance together with the guide bar which moves finely in a feed direction. Then, the pulse voltage of the 2nd piezoelectric element 35 is ceased, the guide bar 24 is displaced finely as the piezoelectric element 25 contracts. At this time, the clamping pieces 31 and 32 generate no clamping force to the guide bar 24, so the carriage 20 stops at its current position because of its inertia even when the guide bar 24 is displaced in the opposite direction from the feed direction, so that it moves forth on the whole. Further, the carriage is moved back by cutting off the pulse voltage to the 1st piezoelectric element 25 after a pulse voltage is applied to the 2nd piezoelectric element 35.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a precision feeding device, and more specifically,
This invention relates to a precision feeding device using an element.

[Prior Art] Generally, in order to send a certain member in a linear direction with high precision, a structure is adopted in which the rotational motion of a motor as a drive source is converted into linear interlocking motion.

Some examples of such structures are shown in Figures 10 and 11.
Shown in Figures (A), (B), and (C).

The example shown in figure m10 is a head carrier of a magnetic disk device.
The carriage shown by reference numeral 1 in the figure is magnetically moved by 1. The kite 2 has one end slidably fitted to the kite par 3.

The other end of the carrier 1 is slidably fitted into a screw 4 disposed parallel to the guide bar 3.

One end of the screw 4 is connected to the output shaft of a stepping motor 5, and the other end is rotatably supported by a bearing 6. A needle 7, which is suspended horizontally on a part of the carrier 1, is partially fitted into the thread groove of the screw 4.

Reference numeral 8 denotes a spindle motor, which has the role of rotating a magnetic disk (not shown), and its center and the magnetic head 2 are on the same axis.

When the stepping motor 5 is rotated based on the above-described structure, the screw 4 rotates, and the needle 7 fitted into the thread groove serves as a nut, and the stepping motor 5 is rotated according to the screw drive principle. The carriage moves in the radial direction of the magnetic disk along the guide bar 3 according to the rotational direction of the magnetic disk, thereby performing magnetic recording and reproduction.

On the other hand, the example shown in FIG. 11(A) is also applied to the feeding mechanism of a hemlock carriage used in a magnetic disk device, and the carriage designated by reference numeral 10 in FIG. 1 is slidably guided by two wooden kite pars 11 and 12. Ru.

The carriage 10 is provided with a magnetic head 13.
A so-called α-wound steel belt 15 is provided on a support member 14 protruding from the side surface of the carriage 13, with both ends thereof being fixed.

On the other hand, what is indicated by the reference numeral 16 is a stepping motor, and the steel belt 15 is attached to a bobbin fixed to the output shaft of the stepping motor.
The α-winding part of is wrapped.

A spindle hub 18 rotates a magnetic disk (not shown).

When the stepping motor 16 is rotated based on the structure described above, the steel belt 1 changes depending on the direction of rotation.
5 is wound up, and the carriage 10 moves in the radial direction of the magnetic disk (not shown) to perform magnetic recording and reproduction.

In addition, the α-wound steel belt 15 is shown in Fig. 11 (B).
The method called 1-2 winding as shown in the figure (C)
There is a method called 1-1 winding as shown in FIG.

[Problems to be Solved by the Invention] All of the dual feed mechanisms employ a configuration that converts the minute rotational movement of the stepping motor into linear motion via a screw drive mechanism or a steel belt. Because of this, there are many parts such as stepping motors, screws, and steel belts, making the whole system complicated and large, and it is not possible to obtain very high precision.

[Means for Solving the Problems] In order to solve the problems described in the present invention, a first piezoelectric element that vibrates the guide bar in the axial direction is provided at one end of the guide bar that guides the transported member. A structure is adopted in which a second piezoelectric element is provided on the side of the conveyed member to generate the clamping force of the clamping member of the guide bar.

[Function] When the above-described structure is adopted, when the guide bar is slightly moved in the feeding direction of the sent member, the first piezoelectric element drives the second piezoelectric element to apply a clamping force to the clamping member. By applying or removing the guide bar, the member to be sent can be moved minutely along with the displacement of the guide bar.

By adjusting the phase of the pulse that excites the drive of the second piezoelectric element, it is also possible to move the member to be sent in the opposite direction. Therefore, if you repeat the above operation,
It is possible to accurately feed the member to be fed by minute distances.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

[First Embodiment] FIGS. 1 to 5 illustrate a first embodiment of the present invention, and are exemplified as being applied to a head carriage feeding mechanism.

In FIGS. 1 to 3, a carriage is designated by the reference numeral 20, and an L-shaped arm 21 is formed at one end of the carriage, and a magnetic head 22 is provided on the upper surface of the horizontal end of the carriage.

Further, a support plate 23 is protruded from the other end of the carriage 20, and a guide bar 24 is slidably fitted into the support plate 23 and the arm 21.

One end of the guide bar 24 is connected to one end of the first piezoelectric element 25 . The other end of the piezoelectric element 25 is a fixed part 26 of the device.
is fixed.

On the other hand, a support plate 27 is provided protruding from the center of the upper surface of the carriage 20. This support plate 27 is formed into an approximately 8-shape, and protruding pieces 29 and 30 are provided on the left and right sides.
A pair of left and right holding pieces 31 and 32 are protruded from the center.

As shown in FIG. 3, the clamping pieces 31 and 32 have 7-shaped notches 31a and 32a formed in opposing positions on the inside of their upper ends, and a chi'r is formed between these notches 31a and 32a. :/<-24 is fitted.

A circular gouge 81 is provided between the proximal ends of a pair of clamping pieces 31 and 32.
! 33 is formed, and furthermore, left and right clamping pieces 31 are formed.
．． Circular gouges 34 are also formed on the outside of the proximal ends of 32, respectively.

By forming these gouged parts 33, 34, hinge parts 31b, 32b are formed at the base ends of each clamping piece 31, 32, and the tips of a pair of clamping pieces 31, 32 can approach and separate from each other. It is designed to make it easier.

On the other hand, a second piezoelectric element 35 is fitted between the left and right projecting pieces 29, 30 and the respective clamping pieces 31 and 32, respectively.

Note that the other end of the guide bar 24 is supported so that the guide bar 24 can be easily displaced in the axial direction.

A piezoelectric element drive circuit 36 is provided on the lower surface of the carriage 20.

Next, the operation of this embodiment configured as above will be explained.

FIGS. 4(A) to 4(C) show the first and second piezoelectric elements 25.
．． 35. FIG. 3A is a timing chart of driving pulses applied to the piezoelectric element 35. FIG. 3A shows the driving pulses of the first piezoelectric element 25 provided on the guide bar side.

Further, FIG. 4(B) shows the drive pulse applied to the second piezoelectric element 35 when the carriage moves in one direction, and FIG. 4(C) shows the drive pulse applied to the second piezoelectric element 35 when the carriage moves in one direction. The driving pulse applied to the second piezoelectric element 35 when moving in the direction is shown.

First, a case will be described in which the carriage 20 moves, for example, from the home position to the return position.

As shown in Figure 4 (A) and CB), the first
Before the piezoelectric element 25 of
The piezoelectric element 35 is driven, and the clamping pieces 31 and 32 are deformed in the direction in which they approach each other. For this reason, one set of clamping pieces 31.32
is a notch 31a.

The guide bar 24 is held via the guide bar 32a.

Therefore, the carriage 20 moves a small distance together with the guide bar 24, which moves slightly in the feeding direction.

Then, when the pulse voltage of the second piezoelectric element 35 is cut off and the pulse voltage applied to the piezoelectric element 25 at the rear part 1 is cut off, the guide bar 24 is slightly displaced as the piezoelectric element 25 contracts.

In this state, the clamping force of the clamping pieces 31 and 32 against the guide/heel 24 is lost, and the carriage 20
4, the arm 21 and the support plate 23 are in sliding contact only through the bearings, so even if the guide bar 24 is displaced in the opposite direction to the feeding direction, the inertia of the carriage 20 will keep the carriage 20 in that position. Stay. Thereafter, the same operation is repeated, and the carriage moves forward by small distances.

The overall moving distance is minute unit distance x number of drive pulses for the second piezoelectric element.

On the other hand, the movement of the carriage in the backward direction utilizes the movement of the kite par, which was in the contraction direction when it was in the forward direction.

That is, ':fS4 As is clear from the figures (A) and (C), after applying the pulse voltage to the second piezoelectric element 35, the first
The pulse voltage to the piezoelectric element 25 is cut off.

Then, the clamping pieces 31 and 32 chuck the guide bar 24 before the guide bar 24 starts to be displaced, and move minutely together as the guide bar moves minutely in the direction of displacement. Then, before the next pulse voltage is applied to the first piezoelectric element 25 after a predetermined period of time has elapsed, the pulse voltage applied to the second piezoelectric element 35 is cut off.

In this state, the clamping pieces 31 and 32 do not hold the guide bar 24, so even if the first piezoelectric element 25 is driven again and the guide bar 24 is displaced, the carriage 20 remains in that position due to inertia. .

Thereafter, the same operation is repeated and a backward operation is performed.

FIGS. 5(A) to 5(C) are diagrams explaining the displacement of the guide bar and the carriage. FIG. 5(A) shows the displacement of the guide bar 24, and FIG. )direction)
(C) shows the displacement in the backward direction of the carriage ((-)
direction).

Note that the minute unit feed distance of the carriage is determined by the amount of displacement of the first piezoelectric element 25, but by appropriately manipulating the applied pulse voltage, minute feed positioning in units of 11 gm can be performed with high precision. .

Since this embodiment is constructed as described below, a highly accurate feeding mechanism can be obtained by using only three piezoelectric elements, and the number of parts is small, making it possible to reduce the size and weight.

[Second Embodiment] FIGS. 6(A) to 6(D) illustrate a second embodiment of the present invention, in which an annular piezoelectric element 37 is used as the clamping means. . This piezoelectric element 37 is attached to the carriage 20 side by means not shown, and when a voltage is applied, it contracts as shown in FIGS. When no voltage is applied, the diameter is enlarged as shown in FIGS. 3(C) and 3(D), and the kite par 24 is released.

This annular piezoelectric element 37 constitutes a clamping means, and
It serves as the second piezoelectric element in the first embodiment.

Even if the clamping means is configured using the annular piezoelectric element 37 in this way, and it is also given the role of the second piezoelectric element in the first embodiment, the same effects as in the first embodiment can be obtained and , the number of parts can be reduced.

[Third Embodiment] FIG. 7 explains a third embodiment of the present invention. In this embodiment, a piezoelectric element 38 is provided between the base ends of two clamping pieces 31 and 32. We are hiring. If such a structure is adopted, the clamping pieces 31 and 32 can be operated with one piezoelectric element, and the structure is further simplified.

[Fourth Embodiment] FIGS. 8(A) and 8(B) illustrate a fourth embodiment of the present invention. In this embodiment, the cross-sectional shape of the guide bar 24 is circular, The shape of the first pressure TfL element 25 is configured as a rectangular laminate, as shown in FIG.
In the example shown in ), the guide bar 24 has a quadrilateral cross-sectional shape, and the first piezoelectric element 25 has a rectangular shape.

Even if the structure as described above is employed, the same effects as those of the embodiments described above can be obtained.

[Fifth Embodiment] FIG. S9 illustrates a fifth embodiment of the present invention, in which first piezoelectric elements 25.25a are provided at both ends of the guide bar 24.

These piezoelectric elements 25, 25a are driven with their phases shifted by π.

If such a structure is adopted, vibrations along the guide bar 24 can be obtained more reliably.

[effect] According to the present invention, as is clear from the above description.

A first piezoelectric element that vibrates a guide bar in the axial direction serves as a drive source for linearly moving a member such as a head carriage with high precision. Since the structure includes a second piezoelectric element that directly or indirectly applies a clamping force to the feeding member, it is possible to feed the feeding member with high precision without using drive members such as motors or belts. , the device can be made smaller and the number of parts can be reduced.

[Brief Description of the Drawings] Figures 1 to 5 explain the first embodiment of the present invention, in which Figure 1 is a perspective view of the drive system, Figure 2 is a side view of the drive system, and Figure 2 is a side view of the drive system. 3 is a front view of the drive system, FIGS. 4(A) to 4(C) are timing charts for explaining the method of driving the piezoelectric element, and FIGS. 5(A) to 5(C) are diagrams showing the displacement and carry of the guide bar.
6(A) to 6(D) are explanatory diagrams of the driving state explaining the second embodiment of the present invention, and FIG.
The figure is a front view of a drive system illustrating a third embodiment of the present invention.
8(A) and 8(B) are perspective views of the guide bar side explaining the fourth embodiment of the present invention, and FIG. 9 is a side view of a portion of the guide bar explaining the fifth embodiment of the present invention. Figure 10 is a plan view for explaining the conventional structure, and Figures 11 (A) to (C) are for explaining other conventional examples. Same figure (B),
(C) is a 41 perspective view of the steel belt. 20... Carriage 24... Guide/9-25
...First piezoelectric element 35...Second piezoelectric element■ (A) (B) Figure 6

Claims (1)

[Scope of Claims] 1) In a precision feeding device that feeds a member to be sent by small distances along a guide bar, a first piezoelectric element that vibrates the guide bar in the axial direction is provided at one end of the guide bar, and A precision feeding device characterized in that a second piezoelectric element is provided on the side thereof, the second piezoelectric element being driven out of phase with the first piezoelectric element and directly or indirectly clamping a member to be fed. 2) Hold the guide bar from both sides on the side of the transported member.
2. A precision feeding device according to claim 1, wherein a pair of clamping pieces are provided, and the second piezoelectric element is provided between the outside of the clamping pieces and the member to be fed. 3) On the side of the material to be transported, a guide bar is held from both sides.
2. The precision feeding device according to claim 1, wherein a pair of clamping pieces are provided, and a second clamping piece is provided between the clamping pieces. 4) The precision feeding device according to claim 1, wherein the second piezoelectric element is provided on the side of the member to be fed in an annular shape surrounding the guide bar. 5) The first piezoelectric element is provided at both ends of the guide bar and is configured to be driven with a phase shift. Precision feed device as described.